WO2016059968A1 - Working vehicle - Google Patents
Working vehicle Download PDFInfo
- Publication number
- WO2016059968A1 WO2016059968A1 PCT/JP2015/077538 JP2015077538W WO2016059968A1 WO 2016059968 A1 WO2016059968 A1 WO 2016059968A1 JP 2015077538 W JP2015077538 W JP 2015077538W WO 2016059968 A1 WO2016059968 A1 WO 2016059968A1
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- WIPO (PCT)
- Prior art keywords
- brake
- transmission
- shaft
- case
- gear
- Prior art date
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60K17/00—Arrangement or mounting of transmissions in vehicles
- B60K17/04—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or kind of gearing
- B60K17/10—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or kind of gearing of fluid gearing
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T11/00—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant
- B60T11/04—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant transmitting mechanically
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T7/00—Brake-action initiating means
- B60T7/02—Brake-action initiating means for personal initiation
- B60T7/04—Brake-action initiating means for personal initiation foot actuated
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D11/00—Steering non-deflectable wheels; Steering endless tracks or the like
- B62D11/02—Steering non-deflectable wheels; Steering endless tracks or the like by differentially driving ground-engaging elements on opposite vehicle sides
- B62D11/06—Steering non-deflectable wheels; Steering endless tracks or the like by differentially driving ground-engaging elements on opposite vehicle sides by means of a single main power source
- B62D11/08—Steering non-deflectable wheels; Steering endless tracks or the like by differentially driving ground-engaging elements on opposite vehicle sides by means of a single main power source using brakes or clutches as main steering-effecting means
Definitions
- work vehicles such as farm work machines such as tractors and special work machines such as crane trucks.
- an engine is mounted on the front part of the body frame, a transmission case is connected to the rear part of the body frame, and the traveling body is supported by the front and rear traveling parts.
- the transmission case incorporates, for example, a traveling transmission gear mechanism, a differential gear mechanism, a PTO transmission gear mechanism, and the like.
- the power of the front engine is transmitted to the rear transmission case, and is transmitted from the differential gear mechanism in the transmission case to at least the left and right rear traveling units. Power is also transmitted from the PTO transmission gear mechanism in the transmission case to a working unit such as a rotary tiller (see, for example, Patent Document 1).
- an inline hydraulic continuously variable transmission is assembled in a mission case.
- the hydraulic continuously variable transmission includes a hydraulic pump unit that transmits power from an engine via an input shaft, and a hydraulic motor unit that transmits a shift output to a rear traveling unit or the like via an output shaft.
- the input shaft and the output shaft are concentric double shafts, and a cylinder block that rotates integrally with the input shaft is fitted on the input shaft.
- a hydraulic pump part is fitted on one side of the input shaft across the cylinder block, and a hydraulic motor part is fitted on the other side.
- the work vehicle includes a forward / reverse switching mechanism that switches the output of the hydraulic continuously variable transmission in the forward or reverse direction, a double speed drive mechanism that increases the rotational speed of the left and right forward traveling units when the traveling vehicle body is turning forward, Furthermore, there is also a brake mechanism that is configured to automatically apply a brake to the rear traveling portion inside the turn during operation of the double speed drive mechanism (a so-called autobrake, see, for example, Patent Document 2).
- hydraulic fluid from a hydraulic source is supplied to a hydraulic device (such as a hydraulic clutch or a hydraulic cylinder) for a hydraulic continuously variable transmission, a forward / reverse switching mechanism, a double speed drive mechanism, a brake mechanism, etc. Activate each of the mechanisms described above.
- This invention makes it a technical subject to provide the work vehicle which improved after examining the above present conditions.
- the present invention includes an engine mounted on a traveling machine body, a transmission case incorporating a hydraulic continuously variable transmission for shifting the power of the engine, and a rear traveling unit provided on the left and right sides of the transmission case via a rear axle case.
- the left and right brake mechanisms for braking the left and right rear traveling units are disposed in the transmission case, and the left and right brake pedals for braking the left and right brake mechanisms are disposed in front of the control seat of the traveling aircraft body.
- the work vehicle is provided with a pair of brake cylinders that operate each of the brake mechanisms and an auto brake valve that controls supply of hydraulic oil to the brake cylinders, and the left and right brake links are connected to the left and right brake links.
- the brake pedal and the left and right brake mechanisms are interlocked and connected, and the left and right brake link bodies are The corresponding brake cylinders are interlocked and connected via a strip member, and the brake pedal is not allowed to follow between the left and right brake link bodies and the left and right brake pedals when the brake mechanism is operated by the brake cylinders.
- One interchangeable member is provided, and a second interchangeable member is provided between the left and right brake link bodies and the left and right cable members so as not to cause the brake cylinder to follow up when the brake mechanism is operated by the brake pedal. Is.
- the brake cylinder pair and the auto brake valve pair are assembled into a brake control case as a unit, and the brake control case is disposed in front of the hydraulic lifting mechanism on the upper surface of the transmission case. It may be said that there is.
- an engine mounted on a traveling machine body a transmission case incorporating a hydraulic continuously variable transmission for shifting the power of the engine, and a rear traveling unit provided on the left and right sides of the transmission case via a rear axle case
- the left and right brake pedals for braking the left and right brake mechanisms are disposed in front of the control seat of the traveling aircraft. Is provided with a pair of brake cylinders that operate each of the brake mechanisms, and an auto brake valve that controls supply of hydraulic oil to each of the brake cylinders, via the left and right brake link bodies.
- the left and right brake pedals and the left and right brake mechanisms are interlocked and connected, and the left and right brake link bodies Since the corresponding brake cylinders are interlocked and connected via a rope member, the brake cylinder can be connected via the rope member to a mechanical connection structure from the brake pedal to the brake mechanism. . For this reason, the structure for operating the left and right brake mechanisms manually and automatically can be gathered mainly by a mechanical connection structure, which can be simplified and made compact and resistant to failure.
- a first interchangeable member that does not follow the brake pedal when the brake mechanism is operated by the brake cylinder is provided between the left and right brake link bodies and the left and right brake pedals, Since a second interchangeable member is provided between the left and right cable members that does not follow the brake cylinder when the brake mechanism is operated by the brake pedal, the brake pedal on one side is inadvertent No follow-up action.
- the brake pedal when the brake pedal is depressed, an unnecessary load is applied to the brake cylinder, and the brake cylinder is not damaged. Therefore, while the structure for operating the left and right brake mechanisms manually and automatically is mainly organized by a mechanical connection structure, it is possible to easily and reliably realize both the manual operation structure and the automatic operation structure.
- the brake cylinder pair and the auto brake valve pair are assembled to a brake control case to form a unit, and the brake control case is disposed in front of the hydraulic lifting mechanism on the upper surface of the transmission case. Therefore, the brake control case incorporating the brake cylinder pair and the auto brake valve pair can be arranged by effectively utilizing the dead space on the upper surface of the mission case, and space saving can be achieved.
- the hydraulic system related to the braking of the work vehicle can be made compact. In the work vehicle production line, it is possible to reduce the number of steps for assembling the brake related hydraulic system.
- the brake cylinder pair and the auto brake valve pair can be attached to and detached from the upper surface of the transmission case with respect to the brake control case in front of the hydraulic lifting mechanism, thereby improving maintainability of the brake control case.
- FIGS. 1 to 8 the traveling machine body 2 of the tractor 1 is supported by a pair of left and right rear wheels 4 as well as a pair of left and right front wheels 3 as a traveling portion.
- the pair of left and right rear wheels 4 corresponds to the rear traveling unit.
- a diesel engine 5 (hereinafter simply referred to as an engine) is mounted on the front portion of the traveling machine body 2, and the tractor 1 is configured to travel forward and backward by driving the rear wheel 4 or the front wheel 3 with the engine 5.
- the engine 5 is covered with a bonnet 6.
- a cabin 7 is installed on the upper surface of the traveling machine body 2.
- Steps 10 on which the operator gets on and off are provided on the left and right outer sides of the cabin 7.
- a fuel tank 11 for supplying fuel to the engine 5 is provided below the bottom of the cabin 7.
- the traveling machine body 2 includes an engine frame 14 having a front bumper 12 and a front axle case 13, and left and right machine body frames 15 detachably fixed to a rear portion of the engine frame 14.
- a front axle 16 is rotatably protruded outward from the left and right ends of the front axle case 13.
- the front wheels 3 are attached to the left and right ends of the front axle case 13 via the front axle 16.
- a transmission case 17 is connected to the rear part of the body frame 15 for appropriately changing the rotational power from the engine 5 and transmitting it to the front and rear four wheels 3, 3, 4, 4.
- a tank frame 18 having a rectangular frame plate shape in a bottom view projecting outward in the left and right directions is bolted to the lower surface sides of the left and right body frames 15 and the mission case 17.
- the fuel tank 11 of the embodiment is divided into left and right two parts.
- the left and right fuel tanks 11 are distributed and mounted on the upper surface side of the left and right projecting portions of the tank frame 18.
- Left and right rear axle cases 19 are mounted on the left and right outer surfaces of the mission case 17 so as to protrude outward.
- Left and right rear axle cases 20 are rotatably inserted in the left and right rear axle cases 19.
- the rear wheel 4 is attached to the mission case 17 via the rear axle 20.
- Upper portions of the left and right rear wheels 4 are covered with left and right rear fenders 21.
- a hydraulic lifting mechanism 22 that lifts and lowers a ground working machine (not shown) such as a rotary tiller is detachably attached.
- the ground work machine is connected to the rear portion of the transmission case 17 via a three-point link mechanism 111 including a pair of left and right lower links 23 and a top link 24.
- a PTO shaft 25 for transmitting a PTO driving force to a working machine such as a rotary tiller is provided to project rearward.
- a flywheel 26 (see FIGS. 4 to 6, 10, and 11) is directly attached to an output shaft (piston rod) of the engine 5 that protrudes rearward from the rear side of the engine 5.
- a main shaft 27 projecting rearward from the flywheel 26 and a main transmission input shaft 28 projecting forward from the front side of the transmission case 17 are connected via a power transmission shaft 29 having universal shaft joints at both ends. (See FIGS. 4 to 6).
- a hydraulic continuously variable transmission 500, a forward / reverse switching mechanism 501, a traveling transmission gear mechanism, a rear wheel differential gear mechanism 506, and the like are arranged.
- the rotational power of the engine 5 is transmitted to the main transmission input shaft 28 of the transmission case 17 via the main driving shaft 27 and the power transmission shaft 29, and is appropriately shifted by the hydraulic continuously variable transmission 500 and the traveling transmission gear mechanism.
- the power is transmitted to the left and right rear wheels 4 via the rear wheel differential gear mechanism 506.
- the front wheel output shaft 30 projecting forward from the front lower part of the transmission case 17 is transmitted to the front wheel projecting rearward from the front axle case 13 containing the front wheel differential gear mechanism 507 via the front wheel drive shaft 31.
- the shaft 508 is connected. Transmission power by the hydraulic continuously variable transmission 500 and the traveling transmission gear mechanism in the transmission case 17 is transmitted from the front wheel output shaft 30, the front wheel drive shaft 31, and the front wheel transmission shaft 508 to the front wheel differential gear in the front axle case 13. It is configured to be transmitted to the left and right front wheels 3 via a mechanism 507.
- a steering column 32 is disposed in front of the control seat 8 in the cabin 7.
- the steering column 32 is erected in a state of being embedded in the back side of the dashboard 33 disposed on the front side inside the cabin 7.
- a steering handle 9 having a substantially round shape in plan view is attached to the upper end side of the handle shaft that protrudes upward from the upper surface of the steering column 32.
- a pair of left and right brake pedals 35 for braking the traveling machine body 2 are arranged on the right side of the steering column 32.
- a forward / reverse switching lever 36 (reverser lever) for switching the traveling direction of the traveling machine body 2 between forward and reverse and a power transmission clutch (not shown) are disconnected.
- a clutch pedal 37 is provided on the left side of the steering column 32.
- An erroneous operation preventing body 38 (reverser guard) extending along the forward / reverse switching lever 36 is disposed on the left side of the steering column 32 and below the forward / reverse switching lever 36.
- an erroneous operation prevention body 38 as a contact preventer below the forward / reverse switching lever 36, the operator is prevented from inadvertently contacting the forward / reverse switching lever 36 when getting on and off the tractor 1.
- An operation display panel 39 incorporating a liquid crystal panel is provided on the upper rear side of the dashboard 33.
- Accelerator pedal 41 for controlling the rotational speed of the engine 5 or the vehicle speed is disposed on the right side of the steering column 32 on the floor plate 40 in front of the control seat 8 in the cabin 7. Note that substantially the entire top surface of the floor plate 40 is formed as a flat surface. Side columns 42 are arranged on both the left and right sides of the control seat 8. Between the control seat 8 and the left side column 42, the parking brake lever 43 for executing the operation of maintaining the left and right rear wheels 4 in a braking state and the traveling speed (vehicle speed) of the tractor 1 are forcibly greatly increased.
- An ultra-low speed lever 44 (creep lever) for reducing the speed
- a sub-shift lever 45 for switching the output range of the traveling sub-speed gear mechanism in the transmission case 17, and a PTO speed change for switching the driving speed of the PTO shaft 25.
- a lever 46 is arranged.
- a differential lock pedal 47 for turning on / off the differential drive of the left and right rear wheels 4 is disposed below the control seat 8.
- a sub-PTO lever 48 for performing an operation for driving the PTO shaft 25 in synchronization with the vehicle speed or an operation for driving it in the reverse direction is disposed on the left rear side of the control seat 8.
- an armrest 49 for placing the arm and elbow of the operator seated on the control seat 8 is provided.
- the armrest 49 is configured separately from the control seat 8 and has a main transmission lever 50 that increases and decreases the traveling speed of the tractor 1 and a dial type that manually changes and adjusts the height position of a ground working machine such as a rotary tiller.
- Working part position dial 51 (elevating dial).
- the armrest 49 is configured to be able to be turned up and rotated in a plurality of stages with the rear end lower part as a fulcrum.
- the left side column 42 includes, in order from the front side, a throttle lever 52 that sets and maintains the rotational speed of the engine 5, and a PTO clutch switch 53 that performs intermittent operation of power transmission from the PTO shaft 25 to a working machine such as a rotary tiller.
- a plurality of hydraulic operation levers 54 (SCV levers) for switching the hydraulic external take-off valve 430 (see FIG. 14) arranged on the upper surface side of the mission case 17 are arranged.
- the hydraulic external take-off valve 430 is for controlling supply of hydraulic oil to hydraulic equipment of another work machine such as a front loader retrofitted to the tractor 1.
- four hydraulic operation levers 54 are arranged in accordance with the number of hydraulic external take-out valves (four stations).
- left and right front support bases 96 that support the front side of the cabin 7 and left and right rear support bases 97 that support the rear part of the cabin 7 are provided.
- the front support 96 is bolted to the front and rear intermediate portions of the outer side surfaces of the left and right aircraft frames 15, and the front bottom of the cabin 7 is anti-vibrated on the upper surface of the front support 96 via the anti-vibration rubber body 98.
- the rear support base 97 is bolted to the middle portion of the left and right widths of the upper surfaces of the left and right rear axle cases 19 that are horizontally extended in the left-right direction, and the vibration-proof rubber body 99 is attached to the upper surface side of the rear support base 97.
- the rear bottom portion of the cabin 7 is supported by vibration isolation. Further, as shown in FIGS. 4 and 5, etc., the rear support base 97 is disposed on the upper surface side of the rear axle case 19, and the steady bracket 101 is disposed on the lower surface side of the rear axle case 19.
- the fastening bracket 101 is fastened with bolts, and both ends of the steady rod body 103 with turnbuckles that can be expanded and contracted are connected to the middle portion of the lower link 23 and the steady bracket 101 that extend in the front-rear direction. The horizontal vibration of 23 is prevented.
- the diesel engine 5 has a cylinder head mounted on a cylinder block having a built-in engine output shaft and piston, and is connected to an air cleaner 221 via a turbocharger 211 on the right side surface of the diesel engine 5 (cylinder head). And an EGR device 210 that recirculates a part of the exhaust gas from the exhaust manifold 204, and a part of the exhaust gas discharged to the exhaust manifold 204 is returned to the intake manifold 203. The maximum combustion temperature during high-load operation is lowered, and NOx (nitrogen oxide) emissions from the diesel engine 5 are reduced.
- NOx nitrogen oxide
- the exhaust manifold 204 connected to the tail pipe 229 and the turbocharger 211 are arranged on the left side surface of the diesel engine 5 (cylinder head). That is, the intake manifold 203 and the exhaust manifold 204 are distributed and arranged on the left and right side surfaces along the engine output shaft in the engine 5.
- a cooling fan 206 is disposed on the front side of the diesel engine 5 (cylinder block).
- the diesel engine 5 includes a continuously regenerative exhaust gas purification device 224 (DPF) disposed on the upper surface side (above the exhaust manifold 204) of the diesel engine 5, and exhaust gas.
- a tail pipe 229 is connected to the exhaust side of the purification device 224.
- the exhaust gas purifying device 224 removes particulate matter (PM) in the exhaust gas discharged from the engine 5 through the tail pipe 229 to the outside of the machine, and at the same time, carbon monoxide (CO) and carbonization in the exhaust gas.
- Hydrogen (HC) is configured to be reduced.
- the bonnet 6 has a front grill 231 at the front lower side, and covers the upper surface side and the front surface side of the engine room 200.
- Side engine covers 232 formed of a perforated plate are arranged on the lower left and right sides of the bonnet 6 to cover the left and right sides of the engine room 200. That is, the hood 6 and the engine cover 232 cover the front, upper, and left and right sides of the diesel engine 5.
- a radiator 235 having a fan shroud 234 attached to the back side is erected on the engine frame 14 so as to be positioned on the front side of the engine 5.
- the fan shroud 234 surrounds the outer peripheral side of the cooling fan 206 and allows the radiator 235 and the cooling fan 206 to communicate with each other.
- An air cleaner 221 is disposed above the front surface of the radiator 235.
- an oil cooler, a fuel cooler, and the like are installed on the front side of the radiator 235.
- the pair of left and right body frames 15 are connected by a support beam frame 236.
- the supporting beam frame 236 is bolted to the left and right airframe frames 15 and is installed on the front end portions (rear side of the engine 5) of the left and right airframe frames 15 via the engine legs having vibration-proof rubber.
- the rear part of the diesel engine 5 is connected to the upper surface of the support beam frame 236.
- 1, 2, 4, 5, 11, and 12, left and right front engine legs 238 having anti-vibration rubber are provided in the middle of the pair of left and right engine frames 14.
- the left and right side surfaces of the front part of the diesel engine 5 are connected. That is, the front side of the diesel engine 5 is supported on the engine frame 14 by vibration isolation, and the rear part of the diesel engine 5 is supported on the front end sides of the pair of left and right body frames 15 via the support beam frame 236.
- the transmission case 17 includes a front transmission case 112 having a main transmission input shaft 28 and the like, a rear transmission case 113 having a rear axle case 19 and the like, and a front side of the rear transmission case 113 on the rear side of the front transmission case 112.
- An intermediate case 114 to be connected is provided.
- the rear ends of the left and right machine body frames 15 are connected to the left and right side surfaces of the intermediate case 114 via the left and right upper and lower machine body connecting shafts 115 and 116.
- the rear end portions of the left and right airframe frames 15 are connected to the left and right side surfaces of the intermediate case 114 by the two upper airframe connecting shaft bodies 115 and the two lower airframe connecting shaft bodies 116.
- the transmission case 17 is integrally connected to form the rear part of the traveling machine body 2, and the front transmission case 112 or the power transmission shaft 29 is disposed between the left and right machine body frames 15, so that the front transmission case is provided. 112 and the like are protected.
- the left and right rear axle cases 19 are attached to the left and right sides of the rear transmission case 113 so as to protrude outward.
- the intermediate case 114 and the rear transmission case 113 are made of cast iron, while the front transmission case 112 is made of aluminum die cast.
- the transmission case 17 is divided into the three parts of the front transmission case 112, the intermediate case 114, and the rear case 113, parts such as shafts and gears are attached to the cases 112 to 114, respectively.
- the front transmission case 112, the intermediate case 114, and the rear transmission case 113 can be assembled. Therefore, the assembly of the mission case 17 can be performed accurately and efficiently.
- left and right rear axle cases 19 are attached to the left and right sides of the rear transmission case 113, and an intermediate case 114 that connects the front transmission case 112 and the rear transmission case 113 is connected to the left and right body frames 15 constituting the traveling vehicle body 2. Therefore, for example, it is possible to remove the front transmission case 112 while the intermediate case 114 and the rear transmission case 113 are attached to the machine body frame 15 and perform operations such as shaft and gear exchange. Therefore, the frequency of dropping (removing) the entire mission case 17 from the tractor 1 can be remarkably lowered, and the workability during maintenance and repair can be improved.
- the intermediate case 114 and the rear transmission case 113 are made of cast iron, and the front transmission case 112 is made of aluminum die cast, the intermediate case 114 connected to the body frame 15 and the left and right rear axle cases 19 are made.
- the rear transmission case 113 to which the two are connected can be configured with high rigidity as a strength member constituting the traveling machine body 2.
- the front transmission case 112 that is not a strength member can be reduced in weight. Therefore, it is possible to reduce the weight of the transmission case 17 as a whole while sufficiently securing the rigidity of the traveling machine body 2.
- the hydraulic lifting mechanism 22 includes left and right hydraulic lift cylinders 117 that are controlled by operation of the working unit position dial 51 and the like, and the upper surface of the rear transmission case 113 of the transmission case 17.
- the left and right lift arms 120 are connected to the left and right lower links 23, and the left and right lift arms 120 are pivotally supported via a lift fulcrum shaft 119 on an openable and closable upper surface lid 118.
- Left and right lift rods 121 are provided.
- a part of the right lift rod 121 is formed by a horizontal cylinder 122 for hydraulic control, and the length of the right lift rod 121 is configured to be adjustable by the horizontal cylinder 122.
- the top link hinge 123 is fixed to the back side of the top cover 118, and the top link 24 is connected to the top link hinge 123 via a hinge pin.
- the piston of the horizontal cylinder 122 is expanded and contracted to change the length of the right lift rod 121.
- the angle is configured to change.
- the transmission case 17 includes a front transmission case 112 having a main transmission input shaft 28 and the like, a rear transmission case 113 having a rear axle case 19 and the like, and a front side of the rear transmission case 113 connected to the rear side of the front transmission case 112.
- An intermediate case 114 is provided.
- the mission case 17 is formed in a hollow box shape as a whole.
- a front lid member 491 is disposed on the front surface of the mission case 17, that is, on the front surface of the front transmission case 112.
- the front lid member 491 is detachably fastened to the front surface of the front transmission case 112 with a plurality of bolts.
- a rear cover member 492 is disposed on the rear surface of the transmission case 17, that is, on the rear surface of the rear transmission case 113.
- the rear lid member 492 is detachably fastened to the rear surface of the rear transmission case 113 with a plurality of bolts.
- An intermediate partition wall 493 that partitions the front transmission case 112 and the intermediate case 114 is integrally formed on the front side in the intermediate case 114.
- a rear partition wall 494 that partitions the inside of the rear transmission case 113 forward and backward is integrally formed in the middle part of the rear transmission case 113.
- the inside of the mission case 17 is divided into three chambers, a front chamber 495, a rear chamber 496, and an intermediate chamber 497, by the middle and rear partition walls 493 and 494.
- a space between the front lid member 491 and the intermediate partition wall 493 in the transmission case 17 (inside the front transmission case 112) is a front chamber 495.
- a rear chamber 496 is formed between the rear lid member 492 and the rear partition wall 494 (inside the rear side of the rear transmission case 113).
- a space between the intermediate partition wall 493 and the rear partition wall 494 is an intermediate chamber 497.
- the front chamber 495, the intermediate chamber 497, and the rear chamber 496 communicate with each other by cutting out part of the partition walls 493 and 494 so that the hydraulic oil (lubricating oil) in the chambers 495 to 497 can move to each other. is doing.
- a mechanical creep transmission gear mechanism 502 that shifts rotational power via the hydraulic continuously variable transmission 500 and a forward / reverse switching mechanism 501 described later.
- a traveling auxiliary transmission gear mechanism 503 and a two-wheel drive / four-wheel drive switching mechanism 504 for switching between the two-wheel drive and the four-wheel drive of the front and rear wheels 3 and 4 are arranged.
- a forward / reverse switching mechanism 501 is provided in the intermediate chamber 497 of the mission case 17 (inside the intermediate case 114 and the front of the rear transmission case 113) to switch the rotational power from the hydraulic continuously variable transmission 500 in the forward or reverse direction. ing.
- a PTO transmission mechanism 505 for appropriately changing the rotational power from the engine 5 and transmitting it to the PTO shaft 25, and a creep transmission gear mechanism 502 or A rear wheel differential gear mechanism 506 that transmits rotational power via the traveling auxiliary transmission gear mechanism 503 to the left and right rear wheels 4 is disposed.
- the creep transmission gear mechanism 502 and the traveling auxiliary transmission gear mechanism 503 correspond to a traveling transmission gear mechanism that multi-shifts the transmission output via the forward / reverse switching mechanism 501.
- a work case hydraulic pump 481 that is driven by the rotational power of the engine 5 and a pump case 480 that houses the traveling hydraulic pump 482 are attached to the front portion of the rear outer case 113.
- a flywheel 26 is directly connected to the output shaft of the engine 5 that protrudes rearward from the rear side surface of the engine 5.
- a main transmission input shaft 28 projecting forward from the front side (front cover member 491) of the transmission case 17 is connected to a main driving shaft 27 projecting rearward from the flywheel 26 via a power transmission shaft 29 having universal joints at both ends. It is connected.
- the rotational power of the engine 5 is transmitted to the main transmission input shaft 28 of the transmission case 17 (front transmission case 112) via the main driving shaft 27 and the power transmission shaft 29, and the hydraulic continuously variable transmission 500 and the creep transmission gear mechanism.
- the main transmission input shaft 28 protruding forward from the front lid member 491 extends in the front-rear direction from the front transmission case 112 to the intermediate case 114 (from the front chamber 495 to the intermediate chamber 497).
- a midway portion before and after the main transmission input shaft 28 is rotatably supported by the intermediate partition wall 493.
- the rear end side of the main transmission input shaft 28 is rotatably supported by an intermediate auxiliary plate 498 that is detachably fastened to the front surface side (intermediate chamber 497 side) of the rear partition wall 494.
- the intermediate auxiliary plate 498 and the rear partition wall 494 are arranged so that a gap in the front-rear direction is left between the two plates 498 and 494.
- an input transmission shaft 511 for transmitting power from the main transmission input shaft 28 is arranged in parallel with the main transmission input shaft 28.
- a hydraulic continuously variable transmission 500 is disposed via an input transmission shaft 511.
- the front side of the hydraulic continuously variable transmission 500 is attached to the inner surface side of the front lid member 491 that detachably closes the front opening of the front transmission case 112.
- the rear end side of the input transmission shaft 511 is rotatably supported by the intermediate auxiliary plate 498 and the rear partition wall 494.
- the hydraulic continuously variable transmission 500 in the front chamber 495 is an inline type in which a main transmission output shaft 512 is concentrically arranged on an input transmission shaft 511.
- a cylindrical main transmission output shaft 512 is fitted in a portion of the input transmission shaft 511 in the intermediate chamber 497.
- the front end side of the main transmission output shaft 512 passes through the intermediate partition wall 493 and is rotatably supported on the intermediate partition wall 493.
- the rear end side of the main transmission output shaft 512 is rotatably supported by the intermediate auxiliary plate 498. Therefore, the rear end side that is the input side of the input transmission shaft 511 protrudes rearward from the rear end of the main transmission output shaft 512.
- a main transmission input gear 513 is fitted on the rear end side of the main transmission input shaft 28 (between the intermediate auxiliary plate 498 and the rear partition wall 494) so as not to be relatively rotatable.
- An input transmission gear 514 that always meshes with the main transmission input gear 513 is fixed to the rear end side of the input transmission shaft 511 (between the intermediate auxiliary plate 498 and the rear partition wall 494). Accordingly, the rotational power of the main transmission input shaft 28 is transmitted to the hydraulic continuously variable transmission 500 via the main transmission input gear 513, the input transmission gear 514, and the input transmission shaft 511.
- a main transmission high-speed gear 516, a main transmission reverse gear 517, and a main transmission low-speed gear 515 are fitted on the main transmission output shaft 512 so as not to rotate relative to each other for traveling output.
- the hydraulic continuously variable transmission 500 includes a variable displacement hydraulic pump unit 521 and a constant displacement hydraulic motor unit 522 that is operated by high-pressure hydraulic oil discharged from the hydraulic pump unit 521.
- the hydraulic pump unit 521 is provided with a pump swash plate 523 that can change the inclination angle with respect to the axis of the input transmission shaft 511 and adjust the amount of hydraulic oil supplied.
- a main transmission hydraulic cylinder 524 that changes and adjusts the inclination angle of the pump swash plate 523 with respect to the axis of the input transmission shaft 511 is linked to the pump swash plate 523.
- the main transmission hydraulic cylinder 524 is assembled to the hydraulic continuously variable transmission 500 and unitized as one member.
- the pump swash plate 523 of the embodiment adjusts the angle in a range between one (positive) maximum inclination angle and the other (negative) maximum inclination angle with a neutral angle of substantially zero inclination (before and after including zero) interposed therebetween. It is possible to set an angle that is inclined to one of the two times when the vehicle speed of the traveling machine body 2 is the lowest (in this case, an inclination angle that is negative and near the maximum).
- the hydraulic motor unit 522 When the inclination angle of the pump swash plate 523 is substantially zero (neutral angle), the hydraulic motor unit 522 is not driven by the hydraulic pump unit 521, and the main transmission output shaft 512 rotates at substantially the same rotational speed as the input transmission shaft 511. To do.
- the hydraulic pump unit 521 activates the hydraulic motor unit 522 at a higher speed than the input transmission shaft 511.
- the main transmission output shaft 512 rotates at a high rotational speed. For this reason, the rotational speed of the hydraulic motor unit 522 is added to the rotational speed of the input transmission shaft 511 and transmitted to the main transmission output shaft 512.
- the shift power (vehicle speed) from the main shift output shaft 512 is changed in proportion to the tilt angle (positive tilt angle) of the pump swash plate 523 within a range of rotation speed higher than the rotation speed of the input transmission shaft 511. Is done.
- the pump swash plate 523 is positive and has an inclination angle near the maximum, the traveling machine body 2 reaches the maximum vehicle speed.
- the hydraulic pump unit 521 decelerates (reverses) the hydraulic motor unit 522, and the input transmission shaft
- the main transmission output shaft 512 rotates at a rotational speed lower than 511.
- the rotational speed of the hydraulic motor unit 522 is subtracted from the rotational speed of the input transmission shaft 511 and transmitted to the main transmission output shaft 512.
- the speed change power from the main speed change output shaft 512 is changed in proportion to the inclination angle (negative inclination angle) of the pump swash plate 523 within the range of the rotation speed lower than the rotation speed of the input transmission shaft 511.
- the traveling machine body 2 has the minimum vehicle speed.
- a pump drive gear 484 is fitted on the pump drive shaft 483 that drives both the working machine and traveling hydraulic pumps 481 and 482 so as not to be relatively rotatable.
- the pump drive gear 484 connects the main transmission input gear 513 of the main transmission input shaft 28 via a flat gear mechanism 485 so that power can be transmitted.
- a lubricating oil pump 518 is provided between the intermediate auxiliary plate 498 and the rear partition wall 494 to supply hydraulic oil for lubrication to the hydraulic continuously variable transmission 500, the forward / reverse switching mechanism 501 and the like.
- the pump gear 520 fixed to the pump shaft 519 of the lubricating oil pump 518 is always meshed with the input transmission gear 514 of the input transmission shaft 511. Therefore, the working machine and traveling hydraulic pumps 481 and 482 and the lubricating oil pump 518 are driven by the rotational power of the engine 5.
- a planetary gear mechanism 526 which is a forward high-speed gear mechanism, and a low-speed gear pair 525, which is a forward low-speed gear mechanism, are disposed at a location in the intermediate chamber 497 of the main transmission input shaft 28 (on the rear side of the main transmission input shaft 28). is doing.
- the planetary gear mechanism 526 includes a sun gear 531 that rotates integrally with an input-side transmission gear 529 that is rotatably supported on the main transmission input shaft 28, and a carrier 532 that rotatably supports a plurality of planetary gears 533 on the same radius. And a ring gear 534 having inner teeth on the inner peripheral surface.
- the sun gear 531 and the ring gear 534 are rotatably fitted on the main transmission input shaft 28.
- the carrier 532 is fitted to the main transmission input shaft 28 so as not to be relatively rotatable.
- the sun gear 531 meshes with each planetary gear 533 of the carrier 532 from the inside of the radius. Further, the inner teeth of the ring gear 534 mesh with the planetary gears 533 from the radially outer side.
- An output side transmission gear 530 that rotates integrally with the ring gear 534 is also rotatably supported on the main transmission input shaft 28.
- the input-side low-speed gear 527 and the output-side low-speed gear 528 constituting the low-speed gear pair 525 have an integral structure, and can rotate between the planetary gear mechanism 526 and the main transmission input gear 513 of the main transmission input shaft 28. It is pivotally supported.
- the main transmission input shaft 28, the input transmission shaft 511, the travel relay shaft 535 extending in parallel with the main transmission output shaft 512, and A travel transmission shaft 536 is disposed.
- the front end side of the travel relay shaft 535 is rotatably supported by the intermediate partition wall 493.
- a rear end side of the travel relay shaft 535 is rotatably supported on the intermediate auxiliary plate 498.
- the front end side of the traveling transmission shaft 536 is rotatably supported by the intermediate partition wall 493.
- the rear end side of the travel transmission shaft 536 is rotatably supported by the intermediate auxiliary plate 498.
- the forward / reverse switching mechanism 501 is provided on the traveling relay shaft 535. That is, the traveling relay shaft 535 has a forward high-speed gear 540 coupled by a wet multi-plate forward high-speed hydraulic clutch 539, a reverse gear 542 coupled by a wet multi-plate reverse hydraulic clutch 541, and a wet multi-plate. A forward low-speed gear 538 connected by a forward low-speed hydraulic clutch 537 of the mold is fitted. A travel relay gear 543 is fitted between the forward high speed hydraulic clutch 539 and the reverse gear 542 in the travel relay shaft 535 so as not to be relatively rotatable. A travel transmission gear 544 that always meshes with the travel relay gear 543 is fitted to the travel transmission shaft 536 so as not to be relatively rotatable.
- the main transmission low speed gear 515 of the main transmission output shaft 512 is always meshed with the input low speed gear 527 of the low speed gear pair 525 on the main transmission input shaft 28 side, and the output low speed gear 528 is always meshed with the forward low speed gear 538.
- the main transmission high speed gear 516 of the main transmission output shaft 512 is always meshed with the input transmission gear 529 of the planetary gear mechanism 526 on the main transmission input shaft 28 side, and the output transmission gear 530 is always meshed with the forward high speed gear 540.
- a main transmission reverse gear 517 of the main transmission output shaft 512 is always meshed with the reverse gear 542.
- the forward low-speed hydraulic clutch 537 or the forward high-speed hydraulic clutch 539 When the forward / reverse switching lever 36 is operated to the forward side, the forward low-speed hydraulic clutch 537 or the forward high-speed hydraulic clutch 539 is in a power connection state, and the forward low-speed gear 538 or forward high-speed gear 540 and the travel relay shaft 535 are connected to each other so as not to be relatively rotatable. Is done. As a result, forward low-speed or high-speed rotational power is transmitted from the main transmission output shaft 512 to the travel relay shaft 535 via the low-speed gear pair 525 or the planetary gear mechanism 526, and power is transmitted from the travel relay shaft 535 to the travel transmission shaft 536. Communicated.
- the reverse hydraulic clutch 541 When the forward / reverse switching lever 36 is operated to the reverse side, the reverse hydraulic clutch 541 enters a power connection state, and the reverse gear 542 and the travel relay shaft 535 are coupled so as not to be relatively rotatable. As a result, the reverse rotational power is transmitted from the main transmission output shaft 512 to the travel relay shaft 535 via the low speed gear pair 525 or the planetary gear mechanism 526, and the power is transmitted from the travel relay shaft 535 to the travel transmission shaft 536.
- a mechanical creep transmission gear mechanism 502 and a traveling auxiliary transmission gear mechanism 503 for shifting rotational power via the forward / reverse switching mechanism 501 are arranged in the front chamber 495 of the transmission case (in the front transmission case 112).
- a travel counter shaft 545 extending coaxially with the travel transmission shaft 536 is disposed in the front chamber 495 (in the front transmission case 112).
- a sub-transmission shaft 546 extending in parallel with the travel counter shaft 545 is disposed from the front transmission case 112 to the rear transmission case 113 (from the front chamber 495 through the intermediate chamber 497 to the rear chamber 496).
- the front end side of the travel counter shaft 545 is rotatably supported by the front lid member 491.
- the rear end side of the travel counter shaft 545 is rotatably supported by the intermediate partition wall 493.
- the front end side of the auxiliary transmission shaft 546 is rotatably supported by the front lid member 491.
- the middle part of the auxiliary transmission shaft 546 is rotatably supported by the intermediate partition wall 493.
- the rear end side of the auxiliary transmission shaft 546 is rotatably supported by the intermediate auxiliary plate 498 and the rear partition wall 494.
- a transmission gear 547 and a creep gear 548 are provided on the rear side of the travel counter shaft 545.
- the transmission gear 547 is rotatably fitted to the travel counter shaft 545 and is pivotally supported on the intermediate partition wall 493 while being connected to the travel transmission shaft 536 so as to rotate integrally therewith.
- the creep gear 548 is fitted on the travel counter shaft 545 so as not to be relatively rotatable.
- a creep shifter 549 is spline-fitted between the transmission gear 547 and the creep gear 548 of the travel counter shaft 545 so as not to be relatively rotatable and slidable in the axial direction.
- the creep shifter 549 slides by turning the ultra low speed lever 44 on and off, and the transmission gear 547 and the creep gear 548 are alternatively connected to the travel counter shaft 545.
- a reduction gear pair 550 is rotatably fitted in a portion of the auxiliary transmission shaft 546 in the front chamber 495 (front transmission case 112).
- the input side reduction gear 551 and the output side reduction gear 552 constituting the reduction gear pair 550 have an integral structure, and the transmission gear 547 of the travel counter shaft 545 always meshes with the input side reduction gear 551 of the auxiliary transmission shaft 546,
- the creep gear 548 is always meshed with the output side reduction gear 552.
- a low speed relay gear 553 and a high speed relay gear 554 are provided on the front side of the travel counter shaft 545.
- the low speed relay gear 553 is fixed to the travel counter shaft 545.
- the high-speed relay gear 554 is fitted on the travel counter shaft 545 so as not to be relatively rotatable.
- a low-speed gear 555 that meshes with the low-speed relay gear 553 and a high-speed gear 556 that meshes with the high-speed relay gear 554 are rotatably fitted on the auxiliary transmission shaft 546 on the front side of the reduction gear pair 550.
- a sub-transmission shifter 557 is spline-fitted between the low-speed gear 555 and the high-speed gear 556 in the sub-transmission shaft 546 so as not to be relatively rotatable and slidable in the axial direction.
- the sub transmission shifter 557 slides and the low speed gear 555 and the high speed gear 556 are alternatively connected to the sub transmission shaft 546.
- the creep gear 548 is connected to the travel counter shaft 545 so as not to be relatively rotatable, and the low speed gear 555 is connected to the sub transmission shaft 546.
- a relatively low speed travel driving force is output from the travel transmission shaft 536 to the front wheel 3 and the rear wheel 4 via the travel counter shaft 545 and the auxiliary transmission shaft 546.
- the ultra-low speed lever 44 and the auxiliary transmission lever 45 are interlocked and connected via a shift check member (details will be described later), and the high-speed side operation of the auxiliary transmission lever 45 and the entry operation of the ultra-low speed lever 45 are performed. It is configured to prohibit compatibility. That is, the sub-shift lever 45 cannot be operated to the high speed side when the ultra-low speed lever 44 is operated and the ultra-low speed lever 44 cannot be operated when the sub-speed lever 45 is operated to the high speed side. .
- the transmission gear 547 is connected to the travel counter shaft 545 so as not to rotate relative to it, and the low speed gear 555 cannot be rotated relative to the sub transmission shaft 546.
- a low-speed traveling driving force is output from the traveling transmission shaft 536 to the front wheels 3 and the rear wheels 4 via the traveling counter shaft 545 and the auxiliary transmission shaft 546.
- the transmission gear 547 is connected to the travel counter shaft 545 so as not to rotate relative to it, and the high speed gear 556 cannot be rotated relative to the sub transmission shaft 546.
- a high-speed travel driving force is output from the travel transmission shaft 536 to the front wheels 3 and the rear wheels 4 via the travel counter shaft 545 and the auxiliary transmission shaft 546.
- the rear end side of the auxiliary transmission shaft 546 passes through the rear partition wall 494 and extends into the rear chamber 496.
- a pinion 558 is provided at the rear end of the auxiliary transmission shaft 546.
- a rear wheel differential gear mechanism 506 for transmitting the driving force to the left and right rear wheels 4 is disposed in the rear chamber 496 (inside the rear side of the rear transmission case 113).
- the rear wheel differential gear mechanism 506 includes a ring gear 559 that meshes with the pinion 558 of the auxiliary transmission shaft 546, a differential gear case 560 provided in the ring gear 559, and a pair of differential output shafts 561 that extend in the left-right direction. Yes.
- a differential output shaft 561 is connected to the rear axle 20 via a final gear 562 and the like.
- the rear wheel 4 is attached to the front end side of the rear axle 20.
- the left and right differential output shafts 561 are provided with brake mechanisms 563, respectively.
- the brake mechanism 563 applies brakes to the left and right rear wheels 4 by two systems of operation and automatic control of the brake pedal 35 and the parking brake lever 43. That is, each brake mechanism 563 is configured such that the brake is applied to the corresponding differential output shaft 561 and the rear wheel 4 when the brake pedal 35 is depressed or the parking brake lever 43 is pulled up.
- the brake cylinder 630 is actuated by the switching operation of the autobrake solenoid valve 631 (see FIG. 14) with respect to the rear wheel 4 on the inside of the turn.
- the brake mechanism 563 for the rear wheel 4 is configured to automatically perform a braking operation (so-called autobrake). For this reason, the tractor 1 can easily execute a small turning turn such as a U-turn (direction change at a headland in a field).
- the differential gear mechanism 506 for the rear wheels is provided with a differential lock mechanism 585 that stops its own differential (the left and right differential output shafts 561 are always driven at a constant speed).
- the differential lock pin constituting the differential lock mechanism 585 is engaged with the differential gear of the differential gear case 560 by depressing the differential lock pedal 47, the differential gear is fixed to the differential gear case 560, and the differential function of the differential gear is determined. Stops, and the left and right differential output shafts 561 are driven at a constant speed.
- a two-wheel drive / four-wheel drive switching mechanism 504 is disposed in the front chamber 495 (front transmission case 112) of the mission case.
- a front wheel input shaft 568 and a front wheel output shaft 30 extending in parallel with the travel counter shaft 545 and the auxiliary transmission shaft 546 are disposed in the front chamber 495 (in the front transmission case 112).
- a driven gear 569 fitted to the front wheel input shaft 568 so as not to rotate relative to the main drive gear 569 fitted so as not to rotate relative to the front end side of the auxiliary transmission shaft 546 is always meshed.
- a double-speed relay gear 571 and a four-wheel drive relay gear 572 are fitted to the front wheel input shaft 568 so as not to rotate relative to each other on both sides of the driven gear 570.
- the front wheel output shaft 30 is provided with a 2WD 4WD switching mechanism 504. That is, the front wheel output shaft 30 is fitted with a double speed gear 574 connected by a wet multi-plate type double-speed hydraulic clutch 573 and a four-wheel drive gear 576 connected by a wet multi-plate type four-wheel hydraulic clutch 575. is doing.
- the double speed relay gear 571 of the front wheel input shaft 568 is always meshed with the double speed gear 574 of the front wheel output shaft 30, and the four-wheel drive relay gear 572 is meshed with the four-wheel gear 576.
- the four-wheel drive hydraulic clutch 575 When a drive changeover switch or drive changeover lever (not shown) is operated to the four-wheel drive side, the four-wheel drive hydraulic clutch 575 is in a power connection state, and the front wheel output shaft 30 and the four-wheel drive gear 576 are connected so as not to be relatively rotatable. Then, as a result of the rotational power being transmitted from the auxiliary transmission shaft 546 to the front wheel output shaft 30 via the front wheel input shaft 568 and the four-wheel drive gear 576, the tractor 1 is a four-wheeled vehicle driven by the front wheel 3 together with the rear wheel 4. It becomes a driving state.
- the double speed hydraulic clutch 573 is in a power connection state, and the front wheel output shaft 30 and the double speed gear 574 are connected so as not to be relatively rotatable. Then, the rotational power is transmitted from the auxiliary transmission shaft 546 to the front wheel output shaft 30 via the front wheel input shaft 568 and the double speed gear 574, so that the rotational speed of the front wheel 3 by the rotational power via the four-wheel drive gear 576 is increased.
- the front wheel 3 is driven at a high speed about twice as high.
- the front wheel differential gear mechanism 507 that transmits a driving force to the left and right front wheels 3 is disposed.
- the front wheel differential gear mechanism 507 includes a ring gear 578 that meshes with a pinion 577 provided on the front end side of the front wheel transmission shaft 508, a differential gear case 579 provided on the ring gear 578, and a pair of differential output shafts 580 extending in the left-right direction. And.
- a differential output shaft 580 is connected to the front axle 16 via a final gear 581 or the like.
- the front wheel 3 is attached to the front end side of the front axle 16.
- a steering hydraulic cylinder 622 (see FIG. 14) for power steering is provided on the outer surface of the front axle case 13 to change the traveling direction of the front wheel 3 to the left and right by the steering operation of the steering handle 9.
- a PTO transmission mechanism 505 that transmits power from the engine 5 to the PTO shaft 25 is disposed in the rear chamber 496 of the transmission case 17 (inside the rear side of the rear transmission case 113).
- a PTO input shaft 591 extending coaxially with the main transmission input shaft 28 is connected to the rear end side of the main transmission input shaft 28 via a PTO hydraulic clutch 590 for power transmission interruption.
- the PTO input shaft 591 is disposed in the rear chamber 496.
- the front end side of the PTO input shaft 591 is rotatably supported on the rear partition wall 494. As shown in FIG.
- upper and lower support wall portions 613 and 614 that partition the rear chamber 496 forward and backward are integrally formed in the rear chamber 496.
- a midway portion between the front and rear of the PTO input shaft 591 is rotatably supported on the upper support wall portion 613 in the rear chamber 496.
- the rear end side of the PTO input shaft 591 is rotatably supported on the inner surface side of the rear cover member 492.
- a PTO transmission shaft 592, a PTO counter shaft 593, and a PTO shaft 25 extending in parallel with the PTO input shaft 591 are disposed.
- the front end side of the PTO transmission shaft 592 is rotatably supported on the upper support wall 613, and the rear end side of the PTO transmission shaft 592 is rotatably supported on the inner surface side of the rear lid member 492.
- the front end side of the PTO counter shaft 593 is rotatably supported on the lower support wall portion 614, and the rear end side of the PTO counter shaft 593 is rotatably supported on the inner surface side of the rear lid member 492.
- the PTO shaft 25 protrudes rearward from the rear lid member 492.
- a front end side of the PTO shaft 25 is rotatably supported on the lower support wall portion 614.
- the PTO hydraulic clutch 590 When the power connection operation of the PTO clutch switch 53 is performed, the PTO hydraulic clutch 590 is in a power connection state, and the main transmission input shaft 28 and the PTO input shaft 591 are coupled so as not to be relatively rotatable. As a result, rotational power is transmitted from the main transmission input shaft 28 toward the PTO input shaft 591.
- the PTO input shaft 591 is provided with a medium speed input gear 597, a low speed input gear 595, a high speed input gear 596, and a reverse shifter gear 598 in order from the front side.
- the medium-speed input gear 597, the low-speed input gear 595, and the high-speed input gear 596 are fitted on the PTO input shaft 591 so as not to be relatively rotatable.
- the reverse shifter gear 598 is spline-fitted to the PTO input shaft 591 so as not to rotate relative to the PTO input shaft 591 and to be slidable in the axial direction.
- the PTO transmission shaft 592 is rotatably fitted with a PTO medium speed gear 601 that meshes with the medium speed input gear 597, a PTO low speed gear 599 that meshes with the low speed input gear 595, and a PTO high speed gear 600 that meshes with the high speed input gear 596. is doing.
- a pair of front and rear PTO transmission shifters 602 and 603 are spline-fitted to the PTO transmission shaft 592 so as not to be relatively rotatable and to be slidable in the axial direction.
- the first PTO shift shifter 602 is disposed between the PTO medium speed gear 601 and the PTO low speed gear 599.
- the second PTO speed shifter 603 is disposed on the rear end side with respect to the PTO high speed gear 600.
- the pair of front and rear PTO shift shifters 602 and 603 are configured to slide in the axial direction in conjunction with the operation of the PTO shift lever 46.
- a PTO transmission gear 604 is fixed between the PTO low-speed gear 599 and the PTO high-speed gear 600 in the PTO transmission shaft 592.
- the PTO counter shaft 593 has a PTO counter gear 605 that meshes with the PTO transmission gear 604, a PTO relay gear 606 that meshes with a PTO output gear 608 that is non-rotatably fitted to the PTO shaft 25, and a PTO reverse gear 607. It is impossible to fit.
- the reverse shifter gear 598 slides and the reverse shifter gear 598 meshes with the PTO reverse gear 607 of the PTO counter shaft 593. ing.
- the pair of front and rear PTO speed shifters 602 and 603 slide along the PTO speed change shaft 592, and the PTO low speed gear 595, the PTO medium speed gear 597, and the PTO high speed gear 596 become the PTO speed change shaft. 592 is alternatively connected.
- low-speed to high-speed PTO shift outputs are transmitted from the PTO shift shaft 592 to the PTO counter shaft 593 via the PTO transmission gear 604 and the PTO counter gear 605, and further, the PTO relay gear 607 and the PTO output gear 608 are transmitted. Is transmitted to the PTO shaft 25.
- the reverse shifter gear 598 meshes with the PTO reverse gear 607, and the rotational power of the PTO input shaft 591 is transmitted to the PTO counter shaft 593 via the reverse shifter gear 598 and the PTO reverse gear 607. Then, the reverse PTO shift output is transmitted from the PTO counter shaft 593 to the PTO shaft 25 via the PTO relay gear 607 and the PTO output gear 608.
- the PTO speed change mechanism 505 of the embodiment is located behind the upper and lower support wall portions 613 and 614 in the rear chamber 496.
- a rear wheel differential gear mechanism 506 is disposed in front of the upper and lower support wall portions 613 and 614 in the rear chamber 496.
- the rear wheel differential gear mechanism 506 and the PTO transmission mechanism 505 are selected and arranged in a simple and compact manner. The assembling workability and maintainability of the case 17 are improved.
- the PTO speed change mechanism 505 is configured to be able to enter and leave the chamber 496 behind the upper and lower support walls 613 and 614.
- the PTO transmission mechanism 505 is mounted on the rear side of the rear chamber 496 from the upper and lower support wall portions 613 and 614, the PTO transmission mechanism 505 is supported by the upper and lower support wall portions 613 and 614 and the rear lid member 492. ing.
- the assembly workability and disassembly workability of the mission case 17 and the maintenance performance of the PTO transmission mechanism 505 can be further improved.
- the PTO input shaft 591 and the PTO transmission shaft 592 are supported by the upper support wall portion 613 and the rear cover member 492, and the PTO counter shaft 593 and the PTO shaft 25 are supported by the lower support wall portion 614 and the rear cover member 492. Is supported. Then, the positional relationship between these shafts 25, 591 to 593 is set so as to be positioned at the top of a rectangle in a rear view (see FIG. 21), and the upper PTO input shaft 591 to the middle PTO speed change shaft 592 and the PTO counter shaft. The PTO output is transmitted to the lower PTO shaft 25 via 593. With this configuration, the reaction forces of the shafts 25, 591 to 593 accompanying the increase in PTO output can be offset. As a result, vibration transmission to the mission case 17 and the traveling machine body 2 can be reduced.
- a longitudinal longitudinal vehicle speed tuning shaft 564 extending in parallel with the auxiliary transmission shaft 546 is disposed from the intermediate chamber 497 to the rear chamber 496.
- a vehicle speed tuning input gear 565 is fitted on the front end side of the vehicle speed tuning shaft 564 so as not to be relatively rotatable.
- the vehicle speed tuning input gear 565 is always meshed with a power branch gear 566 that is fitted in a position in the intermediate chamber 497 of the auxiliary transmission shaft 546 so as not to be relatively rotatable.
- a vehicle speed tuning output gear 610 that is rotatably fitted to the front side of the PTO output gear 608 in the PTO shaft 25 is always meshed with a vehicle speed tuning relay gear 609 fixed to the rear end portion of the vehicle speed tuning shaft 564.
- a vehicle speed tuning shifter 611 is spline-fitted between the vehicle speed tuning output gear 610 and the PTO output gear 608 of the PTO shaft 25 so as not to be relatively rotatable and slidable in the axial direction.
- the function of the sub PTO lever 48 is made different depending on the drive specification of the PTO shaft 25.
- the reverse shifter gear 598 is slid by manual operation of the sub PTO lever 48 and the reverse PTO shift output is transmitted to the PTO shaft 25.
- the vehicle speed synchronization shifter 611 is slid by manual operation of the sub-PTO lever 48, and the PTO shift output synchronized with the vehicle speed is transmitted to the PTO shaft 25.
- the PTO speed change lever 46 and the sub PTO lever 48 are interlocked and connected via a PTO check member (details will be described later). It is configured to prohibit compatibility with the lever 48 entering operation. In other words, the PTO speed change lever 46 cannot be shifted to any position other than neutral when the sub PTO lever 48 is engaged, and the sub PTO lever 48 cannot be engaged when the speed change operation is performed other than neutral. ing.
- the hydraulic circuit 620 of the tractor 1 includes a working machine hydraulic pump 481 and a traveling hydraulic pump 482 that are driven by the rotational power of the engine 5.
- the mission case 17 is used as a working oil tank, and the working oil in the mission case 17 is supplied to the working machine hydraulic pump 481 and the traveling hydraulic pump 482.
- the traveling hydraulic pump 482 is connected to the steering hydraulic cylinder 622 for power steering by the steering handle 9 via the control valve mechanism 621 for power steering, and the hydraulic pump 521 and the hydraulic motor 522 of the hydraulic continuously variable transmission 500. Is connected to a closed loop oil passage 623 connecting the two. While the engine 5 is being driven, the hydraulic oil from the traveling hydraulic pump 482 is always replenished to the closed loop oil passage 623.
- the traveling hydraulic pump 482 includes a main transmission hydraulic switching valve 624 for the main transmission hydraulic cylinder 524 of the hydraulic continuously variable transmission 500, a double speed hydraulic switching valve 625 for the double speed hydraulic clutch 573, and a four-wheel drive for the four-wheel hydraulic clutch 575.
- the hydraulic switching valve 626 is connected to a PTO clutch electromagnetic valve 627 for the PTO hydraulic clutch 590 and a switching valve 628 operated thereby.
- the traveling hydraulic pump 482 includes left and right autobrake solenoid valves 631 as switching valves that actuate a pair of left and right autobrake brake cylinders 630, and a forward low speed clutch solenoid valve 632 that actuates a forward low speed hydraulic clutch 537.
- the work machine hydraulic pump 481 is configured to provide a tread (distance between wheels) between a plurality of hydraulic external extraction valves 430 arranged on the upper surface of the hydraulic lifting mechanism 22 on the rear side of the upper surface of the mission case 17 and the left and right rear wheels 4.
- Left and right tread adjustment solenoid valves 646 that control the supply of hydraulic oil to the right and left tread adjustment hydraulic cylinders 645, and a tilt control solenoid valve 647 that controls the supply of hydraulic oil to the horizontal cylinder 122 provided on the right lift rod 121 ,
- An ascending oil pressure switching valve 648 and a descending oil pressure switching valve 649 for controlling the supply of hydraulic oil to the hydraulic lift cylinder 117 in the hydraulic lifting mechanism 22, an ascending control electromagnetic valve 650 for switching the ascending oil pressure switching valve 648, and a descending oil pressure
- the switching valve 649 is connected to a lowering control electromagnetic valve 651 for operating.
- the left and right tread adjustment electromagnetic valves 646 When the left and right tread adjustment electromagnetic valves 646 are switched and driven, the left and right tread adjustment hydraulic cylinders 645 expand and contract to expand and contract the left and right rear axle cases 19 in the left and right directions. As a result, the tread between the left and right rear wheels 4 becomes longer or shorter.
- the tilt control electromagnetic valve 647 When the tilt control electromagnetic valve 647 is switched and driven, the horizontal cylinder 122 expands and contracts, and the right lower link 23 moves up and down with the lower link pin on the front side as a fulcrum. As a result, the ground work machine tilts left and right with respect to the traveling machine body 2 via the left and right lower links 23, and the left and right tilt angles of the ground work machine change.
- the hydraulic circuit 620 of the tractor 1 includes a lubricating oil pump 518 that is driven by the rotational power of the engine 5 in addition to the working machine hydraulic pump 481 and the traveling hydraulic pump 482 described above.
- the lubricating oil pump 518 includes a PTO clutch hydraulic pressure switching valve 641 that supplies hydraulic oil (lubricating oil) to the lubricating portion of the PTO hydraulic clutch 590, and a lubricating portion of the input transmission shaft 511 that supports the hydraulic continuously variable transmission 500.
- the forward low-speed clutch hydraulic pressure switching valve 642 that supplies hydraulic oil (lubricating oil) to the lubricating portion of the forward low-speed hydraulic clutch 537, and the forward high-speed clutch hydraulic pressure that supplies hydraulic oil (lubricating oil) to the lubricating portion of the forward high-speed hydraulic clutch 539.
- the switching valve 643 is connected to a reverse clutch hydraulic pressure switching valve 644 that supplies hydraulic oil (lubricating oil) to the lubricating portion of the reverse hydraulic clutch 541.
- the hydraulic circuit 620 includes a relief valve, a flow rate adjustment valve, a check valve, an oil cooler, an oil filter, and the like.
- the engine 5 mounted on the traveling machine body 2, the transmission case 17 for shifting the power of the engine 5, and the left and right sides of the transmission case 17 And a rear traveling unit 4 provided via an axle case 19, and a differential mechanism 506 for transmitting transmission power via the mission case 17 to the left and right rear traveling units 4 is disposed in the mission case 17.
- a front chamber 495, an intermediate chamber 497, and a rear chamber 496 are formed in the mission case 17, and the rear chamber 496 includes support wall portions 613 and 614 that divide the rear chamber 496 in the front-rear direction.
- the differential mechanism 506 is disposed in front of the support wall portions 613 and 614 in the rear chamber 496, and the power of the engine 5 is changed to change the speed of the engine. Since the PTO transmission mechanism 505 for transmitting to the PTO shaft 25 projecting rearward from the case 17 is disposed behind the support wall portions 613 and 614 in the rear chamber 496, the rear of the transmission case 17 is In the chamber 496, the differential mechanism 506 and the PTO transmission mechanism 505 (PTO transmission system) can be selected and arranged in a simple and compact manner, and the assembly workability and maintenance performance of the mission case 17 can be improved.
- a rear lid member 492 that detachably closes the rear opening of the transmission case 17 is provided, and the rear lid member 492 is detachably attached to the rear chamber 496 behind the support wall portions 613 and 614.
- the PTO transmission mechanism 505 is configured to be able to enter and exit, and the PTO transmission mechanism 505 is mounted on the rear side of the rear chamber 496 with respect to the support wall portions 613 and 614, the support wall portions 613 and 614 Since the PTO transmission mechanism 505 is supported by the rear cover member 492, the PTO transmission mechanism 505 can be exposed by removing the rear cover member 492 from the transmission case 17. Therefore, the assembly workability and disassembly workability of the transmission case 17 and the maintenance performance of the PTO transmission mechanism 505 can be further improved.
- the three shafts 591 to 593 and the PTO shaft 25 constituting the PTO speed change mechanism 505 are pivoted to the support wall portions 613 and 614 and the rear cover member 492 so as to be positioned at the vertex of the rectangle in the rear view. Therefore, the reaction forces of the shafts 25, 591 to 593 accompanying the increase in the PTO output can be offset. As a result, the life of the bearing structure for each of the shafts 25, 591 to 593 can be extended, and vibration transmission to the transmission case 17 and the traveling machine body 2 can be reduced.
- a pair of brake cylinders 630 for operating the left and right brake mechanisms 563 and an auto brake solenoid valve for controlling the supply of hydraulic oil to each brake cylinder 630 are described.
- the arrangement structure with 631 (auto brake valve) will be described.
- the brake cylinder 630 pair and the auto A pair of brake solenoid valves 631 is arranged.
- a pair of brake cylinders 630 and a pair of autobrake solenoid valves 631 are assembled into a brake control case 664 to form a unit.
- a brake control case 664 incorporating a pair of brake cylinders 630 and a pair of autobrake solenoid valves 631 is detachably fastened to an upper front portion of the rear transmission case 113.
- a PTO valve case 663 is disposed on the left outer surface of the mission case 17, that is, on the front portion on the left outer surface of the rear transmission case 113.
- the brake control case 664 is disposed on the front upper surface of the rear transmission case 113. Therefore, the PTO valve case 663 and the brake control case 664 are placed close to each other on the outer surface side of the rear transmission case 113. Since the hydraulic piping to the brake control case 664 and the hydraulic piping to the PTO valve case 663 (PTO clutch electromagnetic valve 627 and switching valve 628) are close to each other, they are shared.
- 17 and a rear traveling unit 4 provided on both left and right sides of the transmission case 17 via a rear axle case 19, and a left and right brake mechanism 563 that brakes the left and right rear traveling units 4 in the transmission case 17.
- a pair of brake cylinders 630 for operating the brake mechanisms 563 and supply of hydraulic oil to the brake cylinders 630 in a work vehicle in which the hydraulic lifting mechanism 22 is mounted on the upper surface of the transmission case 17.
- An auto brake valve 631 for controlling the brake cylinder 630 and the auto brake valve 631 is assembled to the brake control case 664 to form a unit, and the brake control case 664 is disposed in front of the hydraulic lifting mechanism 22 in the upper surface of the mission case 17.
- the brake control case 664 incorporating the pair of brake cylinders 630 and the pair of auto brake valves 631 can be disposed, and space saving can be achieved.
- the hydraulic system related to the braking of the work vehicle can be made compact. In the work vehicle production line, it is possible to reduce the number of steps for assembling the brake related hydraulic system.
- the pair of brake cylinders 630 and the pair of auto brake valves 631 can be attached and detached together with the brake control case 664 in front of the hydraulic lifting mechanism 22 on the upper surface of the transmission case 17. Maintainability can be improved.
- the transmission case 17 is divided into three parts of a front case 112, an intermediate case 114, and a rear case 113, and the brake control case 664 is attached to the upper front part of the rear case 113.
- the PTO transmission mechanism 505 for shifting the power of the engine 5 and transmitting it to the PTO shaft 25 protruding rearward from the transmission case 17 and the transmission of power to the PTO transmission mechanism 505 are connected.
- a PTO hydraulic clutch 590 to be disconnected, and PTO valves 627 and 628 for operating the PTO hydraulic clutch 590 are attached to the left and right side surfaces of the rear case 113, and the brake control case 664 and the PTO valves 627 and 628 are attached.
- the hydraulic pressure to the brake control case 664 is It can be shared hydraulic piping to the pipe and the PTO valve 627 and 628. Also, the length of the hydraulic piping connecting the brake control case 664 and the PTO valves 627 and 628 can be shortened. For this reason, the handling of the hydraulic piping can be simplified, and the hydraulic system as a whole work vehicle can be made compact. Hydraulic loss can be suppressed.
- a vertically long board support plate (not shown) for fixing and supporting the dashboard 33 is erected on the front side inside the cabin 7, and a horizontally long brake pedal shaft 720 is supported in the middle of the board support plate. I am letting.
- the brake pedal shaft 720 is fitted with base end boss portions 35 a of the left and right brake pedals 35.
- the base end boss portion 35a of the left brake pedal 35 is connected so as to rotate integrally with the brake pedal shaft 720, and the base end boss portion of the right brake pedal 35 is rotatably fitted to the brake pedal shaft 720. is doing.
- a left pedal shaft arm 721 protruding forward is fixed to the left end portion of the brake operation shaft 720.
- a right pedal shaft arm 721 that protrudes forward is fixed to the base end boss portion 35 a of the right brake pedal 35.
- the base end boss portion 37a of the clutch pedal 37 is also rotatably fitted to the brake pedal shaft 720.
- a pair of left and right brake operation shafts 722 are supported on the left and right lower sides of the board support plate.
- Left and right brake operation boss bodies 723 are rotatably fitted to the left and right brake operation shafts 722, respectively.
- Three arms 724 to 726 protrude from each brake operation boss body 723.
- the central arm 724 located at the center of the left and right is connected to the corresponding pedal shaft arm 721 via the vertically long link rod 727.
- the lower end side of the link rod 727 is pivotally attached to the central arm 724, and the upper end side of the link rod 727 is pivotally attached to the pedal shaft arm 721.
- the outer arm 725 positioned on the left and right outer sides is pivotally attached to the front end side of the longitudinally extending brake rod 728 so as to be rotatable.
- braking arms 729 for braking the left and right brake mechanisms 563 are provided on the left and right outer surfaces of the rear transmission case 113 so as to be able to rotate back and forth.
- the rear end side of the brake rod 728 is pivotally attached to the front end side of the brake arm 729 so as to be rotatable.
- the left and right brake mechanisms 563 are operated substantially simultaneously, and the left and right rear wheels 4 are braked.
- a combination of the pedal shaft arm 721, the brake operation boss body 723, the link rod 727, the brake rod 728, and the brake arm 729 corresponds to the brake link body 730.
- an inner arm 726 positioned on the left and right inner side is pivotally attached to a front end side of a push-pull wire 731 as a rope member so as to be rotatable.
- left and right relay links 732 provided corresponding to the brake cylinders 630 are arranged on the left side (brake cylinder 630 side) of the brake control case 664 in the upper surface front portion of the rear transmission case 113. (See FIG. 23).
- the rear end side of the push-pull wire 731 is pivotably attached to the left end side (one end side) of the corresponding relay link 732.
- the right end side (other end side) of each relay link 732 is pivotally attached to the corresponding brake cylinder 630.
- the brake cylinder 630 protrudes by the switching operation of the autobrake solenoid valve 631 with respect to the rear wheel 4 on the inside of the turn, and the push-pull wire 731 is moved via the corresponding relay link 732. Pull backwards. Then, the brake rod 728 is pushed rearward substantially simultaneously via the brake operation boss body 723, and the brake arm 729 rotates backward. As a result, the brake mechanism 563 for the rear wheel 4 inside the turn is automatically braked, and the rear wheel 4 inside the turn is braked (so-called autobrake).
- the first brake pedal 35 is not operated to follow between the left and right brake link bodies 730 and the left and right brake pedals 35 when the brake mechanism 563 is operated by the brake cylinder 630 (when the automatic brake is operated).
- An accommodation member 733 is provided.
- a second interchangeable member 736 is provided between the left and right brake link bodies 730 and the left and right push-pull wires 731 to prevent the brake cylinder 630 from following up when the brake mechanism 563 is operated by the brake pedal 35.
- the first accommodation member 733 of the embodiment is formed on the lower end side of the link rod 727 and the central accommodation pin 734 that pivotably attaches to the lower end side of the link rod 727 and the central arm 724 of the brake operation boss body 723.
- a vertically long first long hole 735 is used.
- a central accommodation pin 734 is loosely fitted in the first elongated hole 735 of the link rod 727.
- the second interchangeable member 736 of the embodiment includes an inner interchangeable pin 737 that pivotably attaches the front end side of the push-pull wire 731 and the inner arm 726 of the brake operation boss body 723, and a front end holding portion of the push-pull wire 731. It is comprised with the 2nd long hole 738 of the front-back longitudinal direction formed in this.
- An inner accommodation pin 737 is loosely fitted in the second elongated hole 738 on the push-pull wire 731 side.
- the brake mechanism 563 when the brake mechanism 563 is operated by the left and right brake pedals 35, the left and right brake rods 728 are pushed rearward substantially simultaneously via the left and right link rods 727, but the inner interchange pin 737 of the inner arm 726 has a second elongated hole. 738 is only moved rearward, and the left and right push-pull wires 731 and therefore both brake cylinders 630 are not operated to follow. Therefore, there is no possibility that the brake cylinder 630 is damaged due to an unnecessary load applied to the brake cylinder 630 when the left and right brake pedals 35 are depressed.
- Both left and right braking arms 729 are linked to a parking brake lever 43 disposed between the control seat 8 and the left side column 42 via a parking brake wire 739 which is an example of a rope member. .
- a parking brake wire 739 which is an example of a rope member.
- the left and right braking arms 729 are rotated rearward via the left and right wires 739, the left and right brake mechanisms 563 are operated substantially simultaneously, and the left and right rear wheels 4 are braked. become.
- the left and right brake arms 729 are rotated rearward and the left and right brake rods 728 are pulled rearward substantially simultaneously, but the central interchange pin 734 of the central arm 724 only moves upward in the first elongated hole 735.
- the link rod 727 and therefore the brake pedal 35 are not moved.
- the inner interchange pin 737 of the inner arm 726 only moves backward in the second elongated hole 738, and does not cause the left and right push-pull wires 731 and therefore both brake cylinders 630 to follow. That is, when the parking brake lever 43 is operated, neither the brake pedal 35 nor the brake cylinder 630 is operated to follow.
- 17 and a rear traveling unit 4 provided on both left and right sides of the transmission case 17 via a rear axle case 19, and a left and right brake mechanism 563 that brakes the left and right rear traveling units 4 in the transmission case 17.
- left and right brake pedals 35 for braking the left and right brake mechanisms 563 are disposed in front of the control seat 8 of the traveling machine body 2, the pair of brake mechanisms 563 are operated.
- the left and right brake pedals 35 and the left and right brake mechanisms 563 are linked to each other via a brake link body 730, and the brake cylinders 730 correspond to the left and right brake link bodies 730 via a rope member 731. Since the 630 is interlocked and connected, the brake cylinder 630 can be connected to the mechanical connection structure from the brake pedal 35 to the brake mechanism 563 via the cord member 731. For this reason, the structure for operating the left and right brake mechanisms 563 manually and automatically can be managed mainly by a mechanical connection structure, and can be simplified and made compact and resistant to failure.
- a first interchangeable member 733 is provided between the left and right brake link bodies 730 and the left and right brake pedals 35 so as not to follow the brake pedal 35 when the brake mechanism 563 is operated by the brake cylinder 630.
- a second interchangeable member 736 that does not follow the brake cylinder 630 when the brake mechanism 563 is operated by the brake pedal 35 is provided.
- the brake pedal 35 on one side does not follow up inadvertently when the automatic brake is activated.
- the brake pedal 35 is depressed, an unnecessary load is applied to the brake cylinder 630 and the brake cylinder 630 is not damaged. Accordingly, the structure for manually and automatically operating the left and right brake mechanisms 563 is mainly organized by a mechanical connection structure, and the compatibility between the manual operation structure and the automatic operation structure can be realized easily and reliably. .
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- Engineering & Computer Science (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Braking Elements And Transmission Devices (AREA)
- Guiding Agricultural Machines (AREA)
- Motor Power Transmission Devices (AREA)
- Transmission Of Braking Force In Braking Systems (AREA)
- Non-Deflectable Wheels, Steering Of Trailers, Or Other Steering (AREA)
- Arrangement Of Transmissions (AREA)
Abstract
Left and right brake pedals 35 and left and right brake mechanisms 563 are connected to and coordinated with each other by means of left and right brake link bodies 730, and brake cylinders 630 corresponding to the left and right brake link bodies 730 are connected thereto and coordinated therewith by means of cable members 731. First adaptable members 733 for preventing, when the brake mechanisms 563 are operated by the brake cylinders 630, the brake pedals 35 from operating following the operation of the brake mechanisms 563 are provided between the left and right brake link bodies 730 and the left and right brake pedals 35. Second adaptable members 736 for preventing, when the brake mechanisms 563 are operated by the brake pedals 35, the brake cylinders 630 from operating following the operation of the brake mechanisms 563 are provided between the left and right brake link bodies 730 and the left and right cable members 731.
Description
例えばトラクタ等の農作業機やクレーン車等の特殊作業機のような作業車両に関するものである。
For example, it relates to work vehicles such as farm work machines such as tractors and special work machines such as crane trucks.
従来、トラクタやホイルローダといった作業車両では、機体フレームの前部にエンジンを搭載し、機体フレームの後部にミッションケースを連結し、前後の走行部によって走行機体を支持している。ミッションケースには、例えば走行変速ギヤ機構、差動ギヤ機構及びPTO変速ギヤ機構等を内蔵している。前側のエンジンの動力は後側のミッションケースに伝わり、ミッションケース内の差動ギヤ機構から少なくとも左右の後方走行部に伝達される。ミッションケース内のPTO変速ギヤ機構からロータリ耕耘機等の作業部にも動力伝達される(例えば特許文献1等参照)。
Conventionally, in work vehicles such as a tractor and a wheel loader, an engine is mounted on the front part of the body frame, a transmission case is connected to the rear part of the body frame, and the traveling body is supported by the front and rear traveling parts. The transmission case incorporates, for example, a traveling transmission gear mechanism, a differential gear mechanism, a PTO transmission gear mechanism, and the like. The power of the front engine is transmitted to the rear transmission case, and is transmitted from the differential gear mechanism in the transmission case to at least the left and right rear traveling units. Power is also transmitted from the PTO transmission gear mechanism in the transmission case to a working unit such as a rotary tiller (see, for example, Patent Document 1).
特許文献1の作業車両では、ミッションケース内にインライン式の油圧無段変速機を組み付けている。当該油圧無段変速機は、エンジンから入力軸を介して動力が伝達される油圧ポンプ部と、出力軸を介して後方走行部等に変速出力を伝達する油圧モータ部とを備えている。入力軸と出力軸とは同心状に位置する二重軸になっていて、入力軸にはこれと一体回転するシリンダブロックを被嵌している。入力軸のうちシリンダブロックを挟んで一方には油圧ポンプ部を被嵌し、他方には油圧モータ部を被嵌している。
In the work vehicle of Patent Document 1, an inline hydraulic continuously variable transmission is assembled in a mission case. The hydraulic continuously variable transmission includes a hydraulic pump unit that transmits power from an engine via an input shaft, and a hydraulic motor unit that transmits a shift output to a rear traveling unit or the like via an output shaft. The input shaft and the output shaft are concentric double shafts, and a cylinder block that rotates integrally with the input shaft is fitted on the input shaft. A hydraulic pump part is fitted on one side of the input shaft across the cylinder block, and a hydraulic motor part is fitted on the other side.
また、作業車両には、油圧無段変速機の出力を正転又は逆転方向に切り換える前後進切換機構や、走行機体の前進旋回時に左右の前方走行部の回転速度を増速させる倍速駆動機構、更には倍速駆動機構の作動中に旋回内側の後方走行部にブレーキを自動的に掛けるように構成したブレーキ機構を備えたものもある(いわゆるオートブレーキ、例えば特許文献2参照)。この種の作業車両では、油圧源からの作動油を、油圧無段変速機、前後進切換機構、倍速駆動機構及びブレーキ機構等に対する油圧装置(油圧クラッチや油圧シリンダ等)に供給することによって、前述の各機構を作動させる。
In addition, the work vehicle includes a forward / reverse switching mechanism that switches the output of the hydraulic continuously variable transmission in the forward or reverse direction, a double speed drive mechanism that increases the rotational speed of the left and right forward traveling units when the traveling vehicle body is turning forward, Furthermore, there is also a brake mechanism that is configured to automatically apply a brake to the rear traveling portion inside the turn during operation of the double speed drive mechanism (a so-called autobrake, see, for example, Patent Document 2). In this type of work vehicle, hydraulic fluid from a hydraulic source is supplied to a hydraulic device (such as a hydraulic clutch or a hydraulic cylinder) for a hydraulic continuously variable transmission, a forward / reverse switching mechanism, a double speed drive mechanism, a brake mechanism, etc. Activate each of the mechanisms described above.
ところで、前述の各油圧装置(これらに対する制御バルブを含む)は作業車両の各部に散在しているため、油圧源から各油圧装置に至る油圧系統は、長く且つ複雑なものになりがちである。油圧系統が長く且つ複雑になると、配管作業の作業工数は自ずと多くなるため、手間が掛かって製造コストの上昇を招来する。油圧系統についてのメンテナンス作業も煩雑になる。特にブレーキペダル及びオートブレーキによって左右のブレーキ機構を作動させる構造に関して、全て油圧式連結構造にしたりすれば、構造が複雑化して製造コストが嵩むことになる。
By the way, since each of the aforementioned hydraulic devices (including control valves for them) is scattered in each part of the work vehicle, the hydraulic system from the hydraulic power source to each hydraulic device tends to be long and complicated. If the hydraulic system is long and complicated, the number of man-hours for piping work naturally increases, which takes time and increases manufacturing costs. Maintenance work for the hydraulic system is also complicated. In particular, regarding the structure in which the left and right brake mechanisms are operated by the brake pedal and the autobrake, if the hydraulic connection structure is used, the structure becomes complicated and the manufacturing cost increases.
本願発明は、上記のような現状を検討して改善を施した作業車両を提供することを技術的課題としている。
This invention makes it a technical subject to provide the work vehicle which improved after examining the above present conditions.
本願発明は、走行機体に搭載したエンジンと、前記エンジンの動力を変速する油圧無段変速機を内蔵したミッションケースと、前記ミッションケースの左右両側に後車軸ケースを介して設けた後方走行部とを備え、前記ミッションケース内に、前記左右の後方走行部を制動させる左右のブレーキ機構を配置し、前記走行機体の操縦座席の前方に、前記左右のブレーキ機構を制動操作する左右のブレーキペダルを配置している作業車両において、前記各ブレーキ機構を作動させる一対のブレーキシリンダと、前記各ブレーキシリンダへの作動油供給を制御するオートブレーキバルブとを備え、左右のブレーキリンク体を介して前記左右のブレーキペダルと前記左右のブレーキ機構とを連動連結すると共に、前記左右のブレーキリンク体には、索条部材を介して対応する前記ブレーキシリンダを連動連結し、前記左右のブレーキリンク体と前記左右のブレーキペダルとの間に、前記ブレーキシリンダによる前記ブレーキ機構の作動時に前記ブレーキペダルを追従作動させない第一融通部材を設け、前記左右のブレーキリンク体と前記左右の索条部材との間に、前記ブレーキペダルによる前記ブレーキ機構の作動時に前記ブレーキシリンダを追従作動させない第二融通部材を設けているというものである。
The present invention includes an engine mounted on a traveling machine body, a transmission case incorporating a hydraulic continuously variable transmission for shifting the power of the engine, and a rear traveling unit provided on the left and right sides of the transmission case via a rear axle case. The left and right brake mechanisms for braking the left and right rear traveling units are disposed in the transmission case, and the left and right brake pedals for braking the left and right brake mechanisms are disposed in front of the control seat of the traveling aircraft body. The work vehicle is provided with a pair of brake cylinders that operate each of the brake mechanisms and an auto brake valve that controls supply of hydraulic oil to the brake cylinders, and the left and right brake links are connected to the left and right brake links. The brake pedal and the left and right brake mechanisms are interlocked and connected, and the left and right brake link bodies are The corresponding brake cylinders are interlocked and connected via a strip member, and the brake pedal is not allowed to follow between the left and right brake link bodies and the left and right brake pedals when the brake mechanism is operated by the brake cylinders. One interchangeable member is provided, and a second interchangeable member is provided between the left and right brake link bodies and the left and right cable members so as not to cause the brake cylinder to follow up when the brake mechanism is operated by the brake pedal. Is.
上記作業車両において、前記ブレーキシリンダの対と前記オートブレーキバルブの対とをブレーキ制御ケースに組み付けてユニット化し、前記ミッションケース上面のうち油圧式昇降機構よりも前方に前記ブレーキ制御ケースを配置しているというものとしてもよい。
In the work vehicle, the brake cylinder pair and the auto brake valve pair are assembled into a brake control case as a unit, and the brake control case is disposed in front of the hydraulic lifting mechanism on the upper surface of the transmission case. It may be said that there is.
本願発明によると、走行機体に搭載したエンジンと、前記エンジンの動力を変速する油圧無段変速機を内蔵したミッションケースと、前記ミッションケースの左右両側に後車軸ケースを介して設けた後方走行部とを備え、前記ミッションケース内に、前記左右の後方走行部を制動させる左右のブレーキ機構を配置し、前記走行機体の操縦座席の前方に、前記左右のブレーキ機構を制動操作する左右のブレーキペダルを配置している作業車両において、前記各ブレーキ機構を作動させる一対のブレーキシリンダと、前記各ブレーキシリンダへの作動油供給を制御するオートブレーキバルブとを備え、左右のブレーキリンク体を介して前記左右のブレーキペダルと前記左右のブレーキ機構とを連動連結すると共に、前記左右のブレーキリンク体には、索条部材を介して対応する前記ブレーキシリンダを連動連結しているから、前記ブレーキペダルから前記ブレーキ機構への機械的連結構造に対して、前記索条部材経由で前記ブレーキシリンダを連結できる。このため、前記左右のブレーキ機構を手動及び自動で作動させる構造を主として機械的な連結構造でとりまとめでき、簡素化してコンパクトに構成しつつ故障にも強いものにできる。
According to the present invention, an engine mounted on a traveling machine body, a transmission case incorporating a hydraulic continuously variable transmission for shifting the power of the engine, and a rear traveling unit provided on the left and right sides of the transmission case via a rear axle case The left and right brake pedals for braking the left and right brake mechanisms are disposed in front of the control seat of the traveling aircraft. Is provided with a pair of brake cylinders that operate each of the brake mechanisms, and an auto brake valve that controls supply of hydraulic oil to each of the brake cylinders, via the left and right brake link bodies. The left and right brake pedals and the left and right brake mechanisms are interlocked and connected, and the left and right brake link bodies Since the corresponding brake cylinders are interlocked and connected via a rope member, the brake cylinder can be connected via the rope member to a mechanical connection structure from the brake pedal to the brake mechanism. . For this reason, the structure for operating the left and right brake mechanisms manually and automatically can be gathered mainly by a mechanical connection structure, which can be simplified and made compact and resistant to failure.
また、前記左右のブレーキリンク体と前記左右のブレーキペダルとの間に、前記ブレーキシリンダによる前記ブレーキ機構の作動時に前記ブレーキペダルを追従作動させない第一融通部材を設け、前記左右のブレーキリンク体と前記左右の索条部材との間に、前記ブレーキペダルによる前記ブレーキ機構の作動時に前記ブレーキシリンダを追従作動させない第二融通部材を設けているから、オートブレーキ作動時に片側のブレーキペダルが不用意に追従作動することがない。一方、前記ブレーキペダルの踏み込み操作時に前記ブレーキシリンダに不要な負荷がかかって、前記ブレーキシリンダが破損するおそれもない。従って、前記左右のブレーキ機構を手動及び自動で作動させる構造を主として機械的な連結構造でとりまとめたものでありながら、手動作動の構造と自動作動の構造との両立を簡単且つ確実に実現できる。
In addition, a first interchangeable member that does not follow the brake pedal when the brake mechanism is operated by the brake cylinder is provided between the left and right brake link bodies and the left and right brake pedals, Since a second interchangeable member is provided between the left and right cable members that does not follow the brake cylinder when the brake mechanism is operated by the brake pedal, the brake pedal on one side is inadvertent No follow-up action. On the other hand, when the brake pedal is depressed, an unnecessary load is applied to the brake cylinder, and the brake cylinder is not damaged. Therefore, while the structure for operating the left and right brake mechanisms manually and automatically is mainly organized by a mechanical connection structure, it is possible to easily and reliably realize both the manual operation structure and the automatic operation structure.
本願発明によると、前記ブレーキシリンダの対と前記オートブレーキバルブの対とをブレーキ制御ケースに組み付けてユニット化し、前記ミッションケース上面のうち油圧式昇降機構よりも前方に前記ブレーキ制御ケースを配置しているから、前記ミッションケース上面のデッドスペースを有効利用して、前記ブレーキシリンダの対及び前記オートブレーキバルブの対を組み込んだ前記ブレーキ制御ケースを配置でき、省スペース化を図れる。作業車両の制動に関連する油圧系統のコンパクト化を図れる。作業車両の製造ラインにおいて、制動関連の油圧系統の組み付け工数を低減できる。前記ブレーキシリンダの対及び前記オートブレーキバルブの対を前記ブレーキ制御ケースごと、前記ミッションケース上面のうち前記油圧式昇降機構よりも前方に取り付け・取り外しでき、前記ブレーキ制御ケースのメンテナンス性を向上できる。
According to the present invention, the brake cylinder pair and the auto brake valve pair are assembled to a brake control case to form a unit, and the brake control case is disposed in front of the hydraulic lifting mechanism on the upper surface of the transmission case. Therefore, the brake control case incorporating the brake cylinder pair and the auto brake valve pair can be arranged by effectively utilizing the dead space on the upper surface of the mission case, and space saving can be achieved. The hydraulic system related to the braking of the work vehicle can be made compact. In the work vehicle production line, it is possible to reduce the number of steps for assembling the brake related hydraulic system. The brake cylinder pair and the auto brake valve pair can be attached to and detached from the upper surface of the transmission case with respect to the brake control case in front of the hydraulic lifting mechanism, thereby improving maintainability of the brake control case.
以下に、本願発明を具体化した実施形態について、農作業用トラクタを図面に基づき説明する。図1~図8に示す如く、トラクタ1の走行機体2は、走行部としての左右一対の前車輪3と同じく左右一対の後車輪4とで支持されている。左右一対の後車輪4が後方走行部に相当するものである。走行機体2の前部にディーゼルエンジン5(以下、単にエンジンという)を搭載し、後車輪4または前車輪3をエンジン5で駆動することによって、トラクタ1が前後進走行するように構成されている。エンジン5はボンネット6にて覆われている。走行機体2の上面にはキャビン7が設置される。該キャビン7の内部には、操縦座席8と、前車輪3を操向操作する操縦ハンドル9とが配置されている。キャビン7の左右外側には、オペレータが乗降するステップ10が設けられている。エンジン5に燃料を供給する燃料タンク11がキャビン7底部の下側に設けられている。
Hereinafter, an embodiment of the present invention will be described with reference to the drawings of a farm tractor. As shown in FIGS. 1 to 8, the traveling machine body 2 of the tractor 1 is supported by a pair of left and right rear wheels 4 as well as a pair of left and right front wheels 3 as a traveling portion. The pair of left and right rear wheels 4 corresponds to the rear traveling unit. A diesel engine 5 (hereinafter simply referred to as an engine) is mounted on the front portion of the traveling machine body 2, and the tractor 1 is configured to travel forward and backward by driving the rear wheel 4 or the front wheel 3 with the engine 5. . The engine 5 is covered with a bonnet 6. A cabin 7 is installed on the upper surface of the traveling machine body 2. Inside the cabin 7, a steering seat 8 and a steering handle 9 for steering the front wheel 3 are arranged. Steps 10 on which the operator gets on and off are provided on the left and right outer sides of the cabin 7. A fuel tank 11 for supplying fuel to the engine 5 is provided below the bottom of the cabin 7.
走行機体2は、前バンパー12及び前車軸ケース13を有するエンジンフレーム14と、エンジンフレーム14の後部に着脱自在に固定した左右の機体フレーム15とにより構成されている。前車軸ケース13の左右両端側から外向きに、前車軸16を回転可能に突出させている。前車軸ケース13の左右両端側に前車軸16を介して前車輪3を取り付けている。機体フレーム15の後部には、エンジン5からの回転動力を適宜変速して前後四輪3,3,4,4に伝達するためのミッションケース17を連結している。左右の機体フレーム15及びミッションケース17の下面側には、左右外向きに張り出した底面視矩形枠板状のタンクフレーム18をボルト締結している。実施形態の燃料タンク11は左右2つに分かれている。タンクフレーム18の左右張り出し部の上面側に、左右の燃料タンク11を振り分けて搭載している。ミッションケース17の左右外側面には、左右の後車軸ケース19を外向きに突出するように装着している。左右の後車軸ケース19には左右の後車軸20を回転可能に内挿している。ミッションケース17に後車軸20を介して後車輪4を取り付けている。左右の後車輪4の上方は左右のリヤフェンダー21によって覆われている。
The traveling machine body 2 includes an engine frame 14 having a front bumper 12 and a front axle case 13, and left and right machine body frames 15 detachably fixed to a rear portion of the engine frame 14. A front axle 16 is rotatably protruded outward from the left and right ends of the front axle case 13. The front wheels 3 are attached to the left and right ends of the front axle case 13 via the front axle 16. A transmission case 17 is connected to the rear part of the body frame 15 for appropriately changing the rotational power from the engine 5 and transmitting it to the front and rear four wheels 3, 3, 4, 4. A tank frame 18 having a rectangular frame plate shape in a bottom view projecting outward in the left and right directions is bolted to the lower surface sides of the left and right body frames 15 and the mission case 17. The fuel tank 11 of the embodiment is divided into left and right two parts. The left and right fuel tanks 11 are distributed and mounted on the upper surface side of the left and right projecting portions of the tank frame 18. Left and right rear axle cases 19 are mounted on the left and right outer surfaces of the mission case 17 so as to protrude outward. Left and right rear axle cases 20 are rotatably inserted in the left and right rear axle cases 19. The rear wheel 4 is attached to the mission case 17 via the rear axle 20. Upper portions of the left and right rear wheels 4 are covered with left and right rear fenders 21.
ミッションケース17の後部には、例えばロータリ耕耘機などの対地作業機(図示省略)を昇降動させる油圧式昇降機構22を着脱可能に取付けている。前記対地作業機は、左右一対のロワーリンク23及びトップリンク24からなる3点リンク機構111を介してミッションケース17の後部に連結される。ミッションケース17の後側面には、ロータリ耕耘機等の作業機にPTO駆動力を伝達するためのPTO軸25を後ろ向きに突設している。
At the rear part of the mission case 17, for example, a hydraulic lifting mechanism 22 that lifts and lowers a ground working machine (not shown) such as a rotary tiller is detachably attached. The ground work machine is connected to the rear portion of the transmission case 17 via a three-point link mechanism 111 including a pair of left and right lower links 23 and a top link 24. On the rear side surface of the mission case 17, a PTO shaft 25 for transmitting a PTO driving force to a working machine such as a rotary tiller is provided to project rearward.
エンジン5の後側面から後ろ向きに突設するエンジン5の出力軸(ピストンロッド)には、フライホイル26(図4~図6、図10及び図11参照)を直結するように取付けている。両端に自在軸継手を有する動力伝達軸29を介して、フライホイル26から後ろ向きに突出した主動軸27と、ミッションケース17前面側から前向きに突出した主変速入力軸28とを連結している(図4~図6参照)。ミッションケース17内には、油圧無段変速機500、前後進切換機構501、走行変速ギヤ機構及び後輪用差動ギヤ機構506などを配置している。エンジン5の回転動力は、主動軸27及び動力伝達軸29を経由してミッションケース17の主変速入力軸28に伝達され、油圧無段変速機500及び走行変速ギヤ機構によって適宜変速され、当該変速動力が後輪用差動ギヤ機構506を介して左右の後車輪4に伝達されるように構成している。
A flywheel 26 (see FIGS. 4 to 6, 10, and 11) is directly attached to an output shaft (piston rod) of the engine 5 that protrudes rearward from the rear side of the engine 5. A main shaft 27 projecting rearward from the flywheel 26 and a main transmission input shaft 28 projecting forward from the front side of the transmission case 17 are connected via a power transmission shaft 29 having universal shaft joints at both ends. (See FIGS. 4 to 6). In the mission case 17, a hydraulic continuously variable transmission 500, a forward / reverse switching mechanism 501, a traveling transmission gear mechanism, a rear wheel differential gear mechanism 506, and the like are arranged. The rotational power of the engine 5 is transmitted to the main transmission input shaft 28 of the transmission case 17 via the main driving shaft 27 and the power transmission shaft 29, and is appropriately shifted by the hydraulic continuously variable transmission 500 and the traveling transmission gear mechanism. The power is transmitted to the left and right rear wheels 4 via the rear wheel differential gear mechanism 506.
ミッションケース17の前面下部から前向きに突出した前車輪出力軸30には、前車輪駆動軸31を介して、前輪用差動ギヤ機構507を内蔵する前車軸ケース13から後向きに突出した前車輪伝達軸508を連結している。ミッションケース17内の油圧無段変速機500及び走行変速ギヤ機構による変速動力は、前車輪出力軸30、前車輪駆動軸31及び前車輪伝達軸508から前車軸ケース13内の前輪用差動ギヤ機構507を経由して、左右の前車輪3に伝達されるように構成している。
The front wheel output shaft 30 projecting forward from the front lower part of the transmission case 17 is transmitted to the front wheel projecting rearward from the front axle case 13 containing the front wheel differential gear mechanism 507 via the front wheel drive shaft 31. The shaft 508 is connected. Transmission power by the hydraulic continuously variable transmission 500 and the traveling transmission gear mechanism in the transmission case 17 is transmitted from the front wheel output shaft 30, the front wheel drive shaft 31, and the front wheel transmission shaft 508 to the front wheel differential gear in the front axle case 13. It is configured to be transmitted to the left and right front wheels 3 via a mechanism 507.
次に、図3、図7及び図8等を参照しながら、キャビン7内部の構造を説明する。キャビン7内における操縦座席8の前方にステアリングコラム32を配置している。ステアリングコラム32は、キャビン7内部の前面側に配置したダッシュボード33の背面側に埋設するような状態で立設している。ステアリングコラム32上面から上向きに突出したハンドル軸の上端側に、平面視略丸型の操縦ハンドル9を取り付けている。
Next, the structure inside the cabin 7 will be described with reference to FIG. 3, FIG. 7 and FIG. A steering column 32 is disposed in front of the control seat 8 in the cabin 7. The steering column 32 is erected in a state of being embedded in the back side of the dashboard 33 disposed on the front side inside the cabin 7. A steering handle 9 having a substantially round shape in plan view is attached to the upper end side of the handle shaft that protrudes upward from the upper surface of the steering column 32.
ステアリングコラム32の右側には、走行機体2を制動操作するための左右一対のブレーキペダル35を配置している。ステアリングコラム32の左側には、走行機体2の進行方向を前進と後進とに切り換え操作するための前後進切換レバー36(リバーサレバー)と、動力継断用のクラッチ(図示省略)を遮断操作するためのクラッチペダル37とを配置している。
On the right side of the steering column 32, a pair of left and right brake pedals 35 for braking the traveling machine body 2 are arranged. On the left side of the steering column 32, a forward / reverse switching lever 36 (reverser lever) for switching the traveling direction of the traveling machine body 2 between forward and reverse and a power transmission clutch (not shown) are disconnected. A clutch pedal 37 is provided.
ステアリングコラム32の左側で前後進切換レバー36の下方には、前後進切換レバー36に沿って延びる誤操作防止体38(リバーサガード)を配置している。接触防止具である誤操作防止体38を前後進切換レバー36下方に配置することによって、トラクタ1に乗降する際に、オペレータが前後進切換レバー36に不用意に接触するのを防止している。ダッシュボード33の背面上部側には、液晶パネルを内蔵した操作表示盤39を設けている。
An erroneous operation preventing body 38 (reverser guard) extending along the forward / reverse switching lever 36 is disposed on the left side of the steering column 32 and below the forward / reverse switching lever 36. By disposing an erroneous operation prevention body 38 as a contact preventer below the forward / reverse switching lever 36, the operator is prevented from inadvertently contacting the forward / reverse switching lever 36 when getting on and off the tractor 1. An operation display panel 39 incorporating a liquid crystal panel is provided on the upper rear side of the dashboard 33.
キャビン7内にある操縦座席8前方の床板40においてステアリングコラム32の右側には、エンジン5の回転速度または車速などを制御するアクセルペダル41を配置している。なお、床板40上面の略全体は平坦面に形成している。操縦座席8を挟んで左右両側にはサイドコラム42を配置している。操縦座席8と左サイドコラム42との間には、左右両後車輪4を制動状態に維持する操作を実行するための駐車ブレーキレバー43と、トラクタ1の走行速度(車速)を強制的に大幅に低減させる超低速レバー44(クリープレバー)と、ミッションケース17内の走行副変速ギヤ機構の出力範囲を切換えるための副変速レバー45と、PTO軸25の駆動速度を切換え操作するためのPTO変速レバー46とを配置している。操縦座席8の下方には、左右両後車輪4の差動駆動をオンオフするためのデフロックペダル47を配置している。操縦座席8の後方左側には、PTO軸25を車速同調駆動させる操作か又は逆転駆動させる操作を実行する副PTOレバー48を配置している。
Accelerator pedal 41 for controlling the rotational speed of the engine 5 or the vehicle speed is disposed on the right side of the steering column 32 on the floor plate 40 in front of the control seat 8 in the cabin 7. Note that substantially the entire top surface of the floor plate 40 is formed as a flat surface. Side columns 42 are arranged on both the left and right sides of the control seat 8. Between the control seat 8 and the left side column 42, the parking brake lever 43 for executing the operation of maintaining the left and right rear wheels 4 in a braking state and the traveling speed (vehicle speed) of the tractor 1 are forcibly greatly increased. An ultra-low speed lever 44 (creep lever) for reducing the speed, a sub-shift lever 45 for switching the output range of the traveling sub-speed gear mechanism in the transmission case 17, and a PTO speed change for switching the driving speed of the PTO shaft 25. A lever 46 is arranged. A differential lock pedal 47 for turning on / off the differential drive of the left and right rear wheels 4 is disposed below the control seat 8. A sub-PTO lever 48 for performing an operation for driving the PTO shaft 25 in synchronization with the vehicle speed or an operation for driving it in the reverse direction is disposed on the left rear side of the control seat 8.
操縦座席8と左サイドコラム42との間には、操縦座席8に着座したオペレータの腕や肘を載せるためのアームレスト49を設けている。アームレスト49は、操縦座席8とは別体に構成すると共に、トラクタ1の走行速度を増減速させる主変速レバー50と、ロータリ耕耘機といった対地作業機の高さ位置を手動で変更調節するダイヤル式の作業部ポジションダイヤル51(昇降ダイヤル)とを備えている。なお、アームレスト49は、後端下部を支点として複数段階に跳ね上げ回動可能な構成になっている。
Between the control seat 8 and the left side column 42, an armrest 49 for placing the arm and elbow of the operator seated on the control seat 8 is provided. The armrest 49 is configured separately from the control seat 8 and has a main transmission lever 50 that increases and decreases the traveling speed of the tractor 1 and a dial type that manually changes and adjusts the height position of a ground working machine such as a rotary tiller. Working part position dial 51 (elevating dial). In addition, the armrest 49 is configured to be able to be turned up and rotated in a plurality of stages with the rear end lower part as a fulcrum.
左サイドコラム42には、前側から順に、エンジン5の回転速度を設定保持するスロットルレバー52と、PTO軸25からロータリ耕耘機等の作業機への動力伝達を継断操作するPTOクラッチスイッチ53と、ミッションケース17の上面側に配置する油圧外部取出バルブ430(図14参照)を切換操作するための複数の油圧操作レバー54(SCVレバー)とを配置している。ここで、油圧外部取出バルブ430は、トラクタ1に後付けされるフロントローダといった別の作業機の油圧機器に作動油を供給制御するためのものである。実施形態では、油圧外部取出バルブの数(4連)に合わせて、油圧操作レバー54を4つ配置している。
The left side column 42 includes, in order from the front side, a throttle lever 52 that sets and maintains the rotational speed of the engine 5, and a PTO clutch switch 53 that performs intermittent operation of power transmission from the PTO shaft 25 to a working machine such as a rotary tiller. A plurality of hydraulic operation levers 54 (SCV levers) for switching the hydraulic external take-off valve 430 (see FIG. 14) arranged on the upper surface side of the mission case 17 are arranged. Here, the hydraulic external take-off valve 430 is for controlling supply of hydraulic oil to hydraulic equipment of another work machine such as a front loader retrofitted to the tractor 1. In the embodiment, four hydraulic operation levers 54 are arranged in accordance with the number of hydraulic external take-out valves (four stations).
さらに、図9~図12などに示す如く、キャビン7の前側を支持する左右の前部支持台96と、キャビン7の後部を支持する左右の後部支持台97を備える。左右の機体フレーム15の機外側面のうち前後中間部に前部支持台96をボルト締結させ、前部支持台96の上面側に防振ゴム体98を介してキャビン7の前側底部を防振支持すると共に、左右方向に水平に延設させる左右の後車軸ケース19の上面のうち左右幅中間部に後部支持台97をボルト締結させ、後部支持台97の上面側に防振ゴム体99を介してキャビン7の後側底部を防振支持している。また、図4及び図5などに示す如く、後車軸ケース19の上面側に後部支持台97を配置し、後車軸ケース19の下面側に振れ止めブラケット101を配置し、後部支持台97と振れ止めブラケット101をボルト締結すると共に、前後方向に延設したロワーリンク23の中間部と振れ止めブラケット101とに、伸縮調節可能なターンバックル付き振れ止めロッド体103の両端部を連結し、ロワーリンク23の左右方向の揺振を防止している。
Furthermore, as shown in FIGS. 9 to 12, etc., left and right front support bases 96 that support the front side of the cabin 7 and left and right rear support bases 97 that support the rear part of the cabin 7 are provided. The front support 96 is bolted to the front and rear intermediate portions of the outer side surfaces of the left and right aircraft frames 15, and the front bottom of the cabin 7 is anti-vibrated on the upper surface of the front support 96 via the anti-vibration rubber body 98. The rear support base 97 is bolted to the middle portion of the left and right widths of the upper surfaces of the left and right rear axle cases 19 that are horizontally extended in the left-right direction, and the vibration-proof rubber body 99 is attached to the upper surface side of the rear support base 97. The rear bottom portion of the cabin 7 is supported by vibration isolation. Further, as shown in FIGS. 4 and 5, etc., the rear support base 97 is disposed on the upper surface side of the rear axle case 19, and the steady bracket 101 is disposed on the lower surface side of the rear axle case 19. The fastening bracket 101 is fastened with bolts, and both ends of the steady rod body 103 with turnbuckles that can be expanded and contracted are connected to the middle portion of the lower link 23 and the steady bracket 101 that extend in the front-rear direction. The horizontal vibration of 23 is prevented.
次に、図4~図8などを参照して、ボンネット6下のディーゼルエンジン5とエンジンルーム構造について説明する。ディーゼルエンジン5は、エンジン出力軸とピストンとを内蔵するシリンダブロック上にシリンダヘッドを搭載しており、ディーゼルエンジン5(シリンダヘッド)右側面には、エアクリーナ221にターボ過給機211を介して接続させる吸気マニホールド203と、排気マニホールド204からの排気ガスの一部を再循環させるEGR装置210を配置し、排気マニホールド204に排出された排気ガスの一部が、吸気マニホールド203に還流することによって、高負荷運転時の最高燃焼温度が低下し、ディーゼルエンジン5からのNOx(窒素酸化物)の排出量が低減するように構成している。一方、ディーゼルエンジン5(シリンダヘッド)左側面に、テールパイプ229に接続させる排気マニホールド204と、ターボ過給機211を配置する。即ち、エンジン5においてエンジン出力軸に沿う左右側面に、吸気マニホールド203と排気マニホールド204とを振分け配置する。ディーゼルエンジン5(シリンダブロック)前面側に冷却ファン206を配置する。
Next, the diesel engine 5 and the engine room structure under the bonnet 6 will be described with reference to FIGS. The diesel engine 5 has a cylinder head mounted on a cylinder block having a built-in engine output shaft and piston, and is connected to an air cleaner 221 via a turbocharger 211 on the right side surface of the diesel engine 5 (cylinder head). And an EGR device 210 that recirculates a part of the exhaust gas from the exhaust manifold 204, and a part of the exhaust gas discharged to the exhaust manifold 204 is returned to the intake manifold 203. The maximum combustion temperature during high-load operation is lowered, and NOx (nitrogen oxide) emissions from the diesel engine 5 are reduced. On the other hand, the exhaust manifold 204 connected to the tail pipe 229 and the turbocharger 211 are arranged on the left side surface of the diesel engine 5 (cylinder head). That is, the intake manifold 203 and the exhaust manifold 204 are distributed and arranged on the left and right side surfaces along the engine output shaft in the engine 5. A cooling fan 206 is disposed on the front side of the diesel engine 5 (cylinder block).
加えて、図4~図8などに示す如く、ディーゼルエンジン5は、ディーゼルエンジン5の上面側(排気マニホールド204上方)に配置する連続再生式の排気ガス浄化装置224(DPF)を備え、排気ガス浄化装置224の排気側にテールパイプ229を接続している。排気ガス浄化装置224によって、エンジン5からテールパイプ229を介して機外に排出される排気ガス中の粒子状物質(PM)が除去されると共に、排気ガス中の一酸化炭素(CO)や炭化水素(HC)が低減されるように構成している。
In addition, as shown in FIGS. 4 to 8 and the like, the diesel engine 5 includes a continuously regenerative exhaust gas purification device 224 (DPF) disposed on the upper surface side (above the exhaust manifold 204) of the diesel engine 5, and exhaust gas. A tail pipe 229 is connected to the exhaust side of the purification device 224. The exhaust gas purifying device 224 removes particulate matter (PM) in the exhaust gas discharged from the engine 5 through the tail pipe 229 to the outside of the machine, and at the same time, carbon monoxide (CO) and carbonization in the exhaust gas. Hydrogen (HC) is configured to be reduced.
さらに、図1~図3などに示す如く、ボンネット6は、前部下側にフロントグリル231を有し、エンジンルーム200の上面側と前面側を覆う。ボンネット6の左右下側に、多孔板で形成した側部エンジンカバー232を配置して、エンジンルーム200左右側方を覆っている。すなわち、ボンネット6及びエンジンカバー232によって、ディーゼルエンジン5の前方、上方及び左右を覆っている。
Further, as shown in FIGS. 1 to 3 and the like, the bonnet 6 has a front grill 231 at the front lower side, and covers the upper surface side and the front surface side of the engine room 200. Side engine covers 232 formed of a perforated plate are arranged on the lower left and right sides of the bonnet 6 to cover the left and right sides of the engine room 200. That is, the hood 6 and the engine cover 232 cover the front, upper, and left and right sides of the diesel engine 5.
また、図4~図8に示すように、ファンシュラウド234を背面側に取り付けたラジエータ235を、エンジン5の前面側に位置するようにエンジンフレーム14上に立設している。ファンシュラウド234は冷却ファン206の外周側を囲っていて、ラジエータ235と冷却ファン206とを連通させている。ラジエータ235前面の上方位置にエアクリーナ221を配置している。なお、ラジエータ235前面側には、上記のインタークーラ他、オイルクーラや燃料クーラなどが設置される。
Further, as shown in FIGS. 4 to 8, a radiator 235 having a fan shroud 234 attached to the back side is erected on the engine frame 14 so as to be positioned on the front side of the engine 5. The fan shroud 234 surrounds the outer peripheral side of the cooling fan 206 and allows the radiator 235 and the cooling fan 206 to communicate with each other. An air cleaner 221 is disposed above the front surface of the radiator 235. In addition to the above intercooler, an oil cooler, a fuel cooler, and the like are installed on the front side of the radiator 235.
一方、図9~図12などに示す如く、左右一対の機体フレーム15は、支持用梁フレーム236によって連結されている。支持用梁フレーム236は、左右の機体フレーム15それぞれとボルト締結して、左右の機体フレーム15の前端部(エンジン5後面側)に架設しており、防振ゴムを有する機関脚体を介して、支持用梁フレーム236上面にディーゼルエンジン5の後部を連結する。なお、図1、図2、図4、図5、図11及び図12に示すように、左右一対のエンジンフレーム14の中途部に、防振ゴムを有する左右の前部機関脚体238を介して、ディーゼルエンジン5前部の左右側面を連結している。即ち、エンジンフレーム14にディーゼルエンジン5前側を防振支持させると共に、左右一対の機体フレーム15の前端側に支持用梁フレーム236を介してディーゼルエンジン5の後部を防振支持させている。
On the other hand, as shown in FIGS. 9 to 12 and the like, the pair of left and right body frames 15 are connected by a support beam frame 236. The supporting beam frame 236 is bolted to the left and right airframe frames 15 and is installed on the front end portions (rear side of the engine 5) of the left and right airframe frames 15 via the engine legs having vibration-proof rubber. The rear part of the diesel engine 5 is connected to the upper surface of the support beam frame 236. 1, 2, 4, 5, 11, and 12, left and right front engine legs 238 having anti-vibration rubber are provided in the middle of the pair of left and right engine frames 14. The left and right side surfaces of the front part of the diesel engine 5 are connected. That is, the front side of the diesel engine 5 is supported on the engine frame 14 by vibration isolation, and the rear part of the diesel engine 5 is supported on the front end sides of the pair of left and right body frames 15 via the support beam frame 236.
次に、図4~図12を参照して、ミッションケース17、油圧式昇降機構22及び3点リンク機構111の取付け構造について説明する。前記ミッションケース17は、主変速入力軸28等を有する前部変速ケース112と、後車軸ケース19などを有する後部変速ケース113と、前部変速ケース112の後側に後部変速ケース113の前側を連結させる中間ケース114を備えている。中間ケース114の左右側面に左右の上下機体連結軸体115,116を介して左右の機体フレーム15の後端部を連結する。即ち、2本の上機体連結軸体115と、2本の下機体連結軸体116にて、中間ケース114の左右両側面に左右の機体フレーム15の後端部を連結させ、機体フレーム15とミッションケース17を一体的に連設して、走行機体2の後部を構成すると共に、左右の機体フレーム15の間に前部変速ケース112または動力伝達軸29などを配置して、前部変速ケース112などを保護するように構成している。左右の後車軸ケース19は、後部変速ケース113の左右両側に外向きに突出するように取り付けている。実施形態では、中間ケース114及び後部変速ケース113を鋳鉄製にする一方、前部変速ケース112をアルミダイキャスト製にしている。
Next, with reference to FIGS. 4 to 12, the mounting structure of the mission case 17, the hydraulic lifting mechanism 22 and the three-point link mechanism 111 will be described. The transmission case 17 includes a front transmission case 112 having a main transmission input shaft 28 and the like, a rear transmission case 113 having a rear axle case 19 and the like, and a front side of the rear transmission case 113 on the rear side of the front transmission case 112. An intermediate case 114 to be connected is provided. The rear ends of the left and right machine body frames 15 are connected to the left and right side surfaces of the intermediate case 114 via the left and right upper and lower machine body connecting shafts 115 and 116. That is, the rear end portions of the left and right airframe frames 15 are connected to the left and right side surfaces of the intermediate case 114 by the two upper airframe connecting shaft bodies 115 and the two lower airframe connecting shaft bodies 116. The transmission case 17 is integrally connected to form the rear part of the traveling machine body 2, and the front transmission case 112 or the power transmission shaft 29 is disposed between the left and right machine body frames 15, so that the front transmission case is provided. 112 and the like are protected. The left and right rear axle cases 19 are attached to the left and right sides of the rear transmission case 113 so as to protrude outward. In the embodiment, the intermediate case 114 and the rear transmission case 113 are made of cast iron, while the front transmission case 112 is made of aluminum die cast.
上記の構成によると、ミッションケース17を、前部変速ケース112、中間ケース114及び後部ケース113の三者に分割して構成しているから、各ケース112~114に軸やギヤ等の部品を予め組み込んでから、前部変速ケース112、中間ケース114及び後部変速ケース113の三者を組み立てできる。従って、ミッションケース17の組み立てを正確に且つ能率よく行える。
According to the above configuration, since the transmission case 17 is divided into the three parts of the front transmission case 112, the intermediate case 114, and the rear case 113, parts such as shafts and gears are attached to the cases 112 to 114, respectively. After being assembled in advance, the front transmission case 112, the intermediate case 114, and the rear transmission case 113 can be assembled. Therefore, the assembly of the mission case 17 can be performed accurately and efficiently.
また、左右の後車軸ケース19を後部変速ケース113の左右両側に取り付け、走行機体2を構成する左右の機体フレーム15に、前部変速ケース112と後部変速ケース113とをつなぐ中間ケース114を連結しているから、例えば中間ケース114及び後部変速ケース113を機体フレーム15に取り付けたままで前部変速ケース112だけを取り外して、軸やギヤの交換といった作業を実行できる。従って、ミッションケース17全体をトラクタ1から降ろす(取り外す)頻度を格段に低くでき、メンテナンス時や修理時の作業性の向上を図れる。
Also, left and right rear axle cases 19 are attached to the left and right sides of the rear transmission case 113, and an intermediate case 114 that connects the front transmission case 112 and the rear transmission case 113 is connected to the left and right body frames 15 constituting the traveling vehicle body 2. Therefore, for example, it is possible to remove the front transmission case 112 while the intermediate case 114 and the rear transmission case 113 are attached to the machine body frame 15 and perform operations such as shaft and gear exchange. Therefore, the frequency of dropping (removing) the entire mission case 17 from the tractor 1 can be remarkably lowered, and the workability during maintenance and repair can be improved.
更に、中間ケース114及び後部変速ケース113を鋳鉄製にする一方、前部変速ケース112をアルミダイキャスト製にしているから、機体フレーム15に連結される中間ケース114と、左右の後車軸ケース19が連結される後部変速ケース113とを、走行機体2を構成する強度メンバーとして高剛性に構成できる。その上で強度メンバーではない前部変速ケース112を軽量化できる。従って、走行機体2の剛性を十分に確保しつつ、ミッションケース17全体としての軽量化を図れる。
Further, while the intermediate case 114 and the rear transmission case 113 are made of cast iron, and the front transmission case 112 is made of aluminum die cast, the intermediate case 114 connected to the body frame 15 and the left and right rear axle cases 19 are made. The rear transmission case 113 to which the two are connected can be configured with high rigidity as a strength member constituting the traveling machine body 2. In addition, the front transmission case 112 that is not a strength member can be reduced in weight. Therefore, it is possible to reduce the weight of the transmission case 17 as a whole while sufficiently securing the rigidity of the traveling machine body 2.
さて、図4~図12に示すように、油圧式昇降機構22は、作業部ポジションダイヤル51等の操作にて作動制御する左右の油圧リフトシリンダ117と、ミッションケース17のうち後部変速ケース113上面側に設ける開閉可能な上面蓋体118にリフト支点軸119を介して基端側を回動可能に軸支する左右のリフトアーム120と、左右のロワーリンク23に左右のリフトアーム120を連結させる左右のリフトロッド121を有している。右のリフトロッド121の一部を油圧制御用の水平シリンダ122にて形成し、右のリフトロッド121の長さを水平シリンダ122にて伸縮調節可能に構成している。
As shown in FIGS. 4 to 12, the hydraulic lifting mechanism 22 includes left and right hydraulic lift cylinders 117 that are controlled by operation of the working unit position dial 51 and the like, and the upper surface of the rear transmission case 113 of the transmission case 17. The left and right lift arms 120 are connected to the left and right lower links 23, and the left and right lift arms 120 are pivotally supported via a lift fulcrum shaft 119 on an openable and closable upper surface lid 118. Left and right lift rods 121 are provided. A part of the right lift rod 121 is formed by a horizontal cylinder 122 for hydraulic control, and the length of the right lift rod 121 is configured to be adjustable by the horizontal cylinder 122.
なお、図7、図8及び図10などに示す如く、上面蓋体118の背面側にトップリンクヒンジ123を固着し、トップリンクヒンジ123にヒンジピンを介してトップリンク24を連結する。トップリンク24と左右のロワーリンク23に対地作業機を支持した状態下で、水平シリンダ122のピストンを伸縮させて、右のリフトロッド121の長さを変更した場合、前記対地作業機の左右傾斜角度が変化するように構成している。
7, 8, 10, etc., the top link hinge 123 is fixed to the back side of the top cover 118, and the top link 24 is connected to the top link hinge 123 via a hinge pin. When the ground work machine is supported by the top link 24 and the left and right lower links 23, the piston of the horizontal cylinder 122 is expanded and contracted to change the length of the right lift rod 121. The angle is configured to change.
次に、図13及び図15~図20等を参照しながら、ミッションケース17の内部構造及びトラクタ1の動力伝達系統について説明する。ミッションケース17は、主変速入力軸28等を有する前部変速ケース112と、後車軸ケース19等を有する後部変速ケース113と、前部変速ケース112の後側に後部変速ケース113の前側を連結させる中間ケース114を備えている。ミッションケース17は全体として中空箱形に形成されている。
Next, the internal structure of the mission case 17 and the power transmission system of the tractor 1 will be described with reference to FIG. 13 and FIGS. The transmission case 17 includes a front transmission case 112 having a main transmission input shaft 28 and the like, a rear transmission case 113 having a rear axle case 19 and the like, and a front side of the rear transmission case 113 connected to the rear side of the front transmission case 112. An intermediate case 114 is provided. The mission case 17 is formed in a hollow box shape as a whole.
ミッションケース17の前面、すなわち前部変速ケース112の前面に前蓋部材491を配置している。前蓋部材491は前部変速ケース112の前面に複数のボルトで着脱可能に締結している。ミッションケース17の後面、すなわち後部変速ケース113の後面に後蓋部材492を配置している。後蓋部材492は後部変速ケース113の後面に複数のボルトで着脱可能に締結している。中間ケース114内の前面側には、前部変速ケース112と中間ケース114との間を仕切る中間仕切り壁493を一体的に形成している。後部変速ケース113の前後中途部には、後部変速ケース113内を前後に仕切る後部仕切り壁494を一体的に形成している。
A front lid member 491 is disposed on the front surface of the mission case 17, that is, on the front surface of the front transmission case 112. The front lid member 491 is detachably fastened to the front surface of the front transmission case 112 with a plurality of bolts. A rear cover member 492 is disposed on the rear surface of the transmission case 17, that is, on the rear surface of the rear transmission case 113. The rear lid member 492 is detachably fastened to the rear surface of the rear transmission case 113 with a plurality of bolts. An intermediate partition wall 493 that partitions the front transmission case 112 and the intermediate case 114 is integrally formed on the front side in the intermediate case 114. A rear partition wall 494 that partitions the inside of the rear transmission case 113 forward and backward is integrally formed in the middle part of the rear transmission case 113.
従って、ミッションケース17内部は、中間及び後部仕切り壁493,494によって、前室495、後室496及び中間室497の三つの室に区画されている。ミッションケース17内部のうち前蓋部材491と中間仕切り壁493との間の空間(前部変速ケース112内部)が前室495となっている。後蓋部材492と後部仕切り壁494との間(後部変速ケース113後側の内部)が後室496となっている。中間仕切り壁493と後部仕切り壁494との間の空間(中間ケース114及び後部変速ケース113前側の内部)が中間室497となっている。なお、前室495、中間室497及び後室496は、各室495~497内の作動油(潤滑油)が相互に移動し得るように各仕切り壁493,494の一部を切り欠いて連通している。
Therefore, the inside of the mission case 17 is divided into three chambers, a front chamber 495, a rear chamber 496, and an intermediate chamber 497, by the middle and rear partition walls 493 and 494. A space between the front lid member 491 and the intermediate partition wall 493 in the transmission case 17 (inside the front transmission case 112) is a front chamber 495. A rear chamber 496 is formed between the rear lid member 492 and the rear partition wall 494 (inside the rear side of the rear transmission case 113). A space between the intermediate partition wall 493 and the rear partition wall 494 (inside the intermediate case 114 and the front side of the rear transmission case 113) is an intermediate chamber 497. The front chamber 495, the intermediate chamber 497, and the rear chamber 496 communicate with each other by cutting out part of the partition walls 493 and 494 so that the hydraulic oil (lubricating oil) in the chambers 495 to 497 can move to each other. is doing.
ミッションケース17の前室495内(前部変速ケース112内)には、油圧無段変速機500と、後述する前後進切換機構501を経由した回転動力を変速する機械式のクリープ変速ギヤ機構502及び走行副変速ギヤ機構503と、前後車輪3,4の二駆と四駆とを切り換える二駆四駆切換機構504とを配置している。ミッションケース17の中間室497内(中間ケース114及び後部変速ケース113前側の内部)には、油圧無段変速機500からの回転動力を正転又は逆転方向に切り換える前後進切換機構501を配置している。ミッションケース17の後室496内(後部変速ケース113後側の内部)には、エンジン5からの回転動力を適宜変速してPTO軸25に伝達するPTO変速機構505と、クリープ変速ギヤ機構502又は走行副変速ギヤ機構503を経由した回転動力を左右の後車輪4に伝達する後輪用差動ギヤ機構506とを配置している。クリープ変速ギヤ機構502及び走行副変速ギヤ機構503は、前後進切換機構501経由の変速出力を多段変速する走行変速ギヤ機構に相当するものである。後部変速ケース113の右外面前部には、エンジン5の回転動力で駆動する作業機用油圧ポンプ481及び走行用油圧ポンプ482を収容したポンプケース480を取り付けている。
In the front chamber 495 (in the front transmission case 112) of the transmission case 17, a mechanical creep transmission gear mechanism 502 that shifts rotational power via the hydraulic continuously variable transmission 500 and a forward / reverse switching mechanism 501 described later. In addition, a traveling auxiliary transmission gear mechanism 503 and a two-wheel drive / four-wheel drive switching mechanism 504 for switching between the two-wheel drive and the four-wheel drive of the front and rear wheels 3 and 4 are arranged. A forward / reverse switching mechanism 501 is provided in the intermediate chamber 497 of the mission case 17 (inside the intermediate case 114 and the front of the rear transmission case 113) to switch the rotational power from the hydraulic continuously variable transmission 500 in the forward or reverse direction. ing. In the rear chamber 496 of the transmission case 17 (inside the rear side of the rear transmission case 113), a PTO transmission mechanism 505 for appropriately changing the rotational power from the engine 5 and transmitting it to the PTO shaft 25, and a creep transmission gear mechanism 502 or A rear wheel differential gear mechanism 506 that transmits rotational power via the traveling auxiliary transmission gear mechanism 503 to the left and right rear wheels 4 is disposed. The creep transmission gear mechanism 502 and the traveling auxiliary transmission gear mechanism 503 correspond to a traveling transmission gear mechanism that multi-shifts the transmission output via the forward / reverse switching mechanism 501. A work case hydraulic pump 481 that is driven by the rotational power of the engine 5 and a pump case 480 that houses the traveling hydraulic pump 482 are attached to the front portion of the rear outer case 113.
図4~図6に示すように、エンジン5の後側面から後ろ向きに突設するエンジン5の出力軸にはフライホイル26を直結している。フライホイル26から後ろ向きに突出した主動軸27に、両端に自在軸継手を有する動力伝達軸29を介して、ミッションケース17前面(前蓋部材491)側から前向きに突出した主変速入力軸28を連結している。エンジン5の回転動力は、主動軸27及び動力伝達軸29を経由してミッションケース17(前部変速ケース112)の主変速入力軸28に伝達され、油圧無段変速機500とクリープ変速ギヤ機構502又は走行副変速ギヤ機構503とによって適宜変速されてから、後輪用差動ギヤ機構506に伝達され、左右の後車輪4を駆動させる。クリープ変速ギヤ機構502又は走行副変速ギヤ機構503を経由した変速動力は、二駆四駆切換機構504から前車輪出力軸30、前車輪駆動軸31及び前車輪伝達軸508を介して、前車軸ケース13内の前輪用差動ギヤ機構507に伝達され、左右の前車輪3を駆動させる。
As shown in FIGS. 4 to 6, a flywheel 26 is directly connected to the output shaft of the engine 5 that protrudes rearward from the rear side surface of the engine 5. A main transmission input shaft 28 projecting forward from the front side (front cover member 491) of the transmission case 17 is connected to a main driving shaft 27 projecting rearward from the flywheel 26 via a power transmission shaft 29 having universal joints at both ends. It is connected. The rotational power of the engine 5 is transmitted to the main transmission input shaft 28 of the transmission case 17 (front transmission case 112) via the main driving shaft 27 and the power transmission shaft 29, and the hydraulic continuously variable transmission 500 and the creep transmission gear mechanism. After being appropriately shifted by 502 or the traveling auxiliary transmission gear mechanism 503, it is transmitted to the rear wheel differential gear mechanism 506 to drive the left and right rear wheels 4. Shift power via the creep transmission gear mechanism 502 or the traveling auxiliary transmission gear mechanism 503 is transmitted from the two-wheel drive and four-wheel drive switching mechanism 504 to the front axle via the front wheel output shaft 30, the front wheel drive shaft 31, and the front wheel transmission shaft 508. This is transmitted to the front wheel differential gear mechanism 507 in the case 13 to drive the left and right front wheels 3.
前蓋部材491から前向きに突出した主変速入力軸28は、前部変速ケース112から中間ケース114(前室495から中間室497)にわたって前後方向に延びている。主変速入力軸28の前後中途部は中間仕切り壁493に回転可能に軸支している。主変速入力軸28の後端側は、後部仕切り壁494の前面側(中間室497側)に着脱可能に締結した中間補助プレート498に回転可能に軸支している。中間補助プレート498と後部仕切り壁494とは、両者498,494の間に前後方向の隙間が空くように配置している。前部変速ケース112から中間ケース114にわたって(前室495から中間室497にわたって)は、主変速入力軸28から動力伝達される入力伝達軸511を主変速入力軸28と平行状に配置している。前部変速ケース112内(前室495内)には、入力伝達軸511を介して油圧無段変速機500を配置している。油圧無段変速機500の前部側は、前部変速ケース112の前面開口部を着脱可能に塞ぐ前蓋部材491の内面側に取り付けている。入力伝達軸511の後端側は中間補助プレート498と後部仕切り壁494とに回転可能に軸支している。
The main transmission input shaft 28 protruding forward from the front lid member 491 extends in the front-rear direction from the front transmission case 112 to the intermediate case 114 (from the front chamber 495 to the intermediate chamber 497). A midway portion before and after the main transmission input shaft 28 is rotatably supported by the intermediate partition wall 493. The rear end side of the main transmission input shaft 28 is rotatably supported by an intermediate auxiliary plate 498 that is detachably fastened to the front surface side (intermediate chamber 497 side) of the rear partition wall 494. The intermediate auxiliary plate 498 and the rear partition wall 494 are arranged so that a gap in the front-rear direction is left between the two plates 498 and 494. From the front transmission case 112 to the intermediate case 114 (from the front chamber 495 to the intermediate chamber 497), an input transmission shaft 511 for transmitting power from the main transmission input shaft 28 is arranged in parallel with the main transmission input shaft 28. . In the front transmission case 112 (in the front chamber 495), a hydraulic continuously variable transmission 500 is disposed via an input transmission shaft 511. The front side of the hydraulic continuously variable transmission 500 is attached to the inner surface side of the front lid member 491 that detachably closes the front opening of the front transmission case 112. The rear end side of the input transmission shaft 511 is rotatably supported by the intermediate auxiliary plate 498 and the rear partition wall 494.
前室495内にある油圧無段変速機500は、入力伝達軸511に主変速出力軸512を同心状に配置したインライン式のものである。入力伝達軸511のうち中間室497内の箇所に、円筒形の主変速出力軸512を被嵌している。主変速出力軸512の前端側は中間仕切り壁493を貫通していて、中間仕切り壁493に回転可能に軸支している。主変速出力軸512の後端側は中間補助プレート498に回転可能に軸支している。従って、入力伝達軸511の入力側である後端側の方が主変速出力軸512の後端よりも後方に突出している。主変速入力軸28の後端側(中間補助プレート498と後部仕切り壁494との間)には主変速入力ギヤ513を相対回転不能に被嵌している。入力伝達軸511の後端側(中間補助プレート498と後部仕切り壁494との間)には、主変速入力ギヤ513に常時噛み合う入力伝達ギヤ514を固着している。従って、主変速入力軸28の回転動力は、主変速入力ギヤ513、入力伝達ギヤ514及び入力伝達軸511を介して油圧無段変速機500に伝達される。主変速出力軸512には、走行出力用として、主変速高速ギヤ516、主変速逆転ギヤ517及び主変速低速ギヤ515を相対回転不能に被嵌している。
The hydraulic continuously variable transmission 500 in the front chamber 495 is an inline type in which a main transmission output shaft 512 is concentrically arranged on an input transmission shaft 511. A cylindrical main transmission output shaft 512 is fitted in a portion of the input transmission shaft 511 in the intermediate chamber 497. The front end side of the main transmission output shaft 512 passes through the intermediate partition wall 493 and is rotatably supported on the intermediate partition wall 493. The rear end side of the main transmission output shaft 512 is rotatably supported by the intermediate auxiliary plate 498. Therefore, the rear end side that is the input side of the input transmission shaft 511 protrudes rearward from the rear end of the main transmission output shaft 512. A main transmission input gear 513 is fitted on the rear end side of the main transmission input shaft 28 (between the intermediate auxiliary plate 498 and the rear partition wall 494) so as not to be relatively rotatable. An input transmission gear 514 that always meshes with the main transmission input gear 513 is fixed to the rear end side of the input transmission shaft 511 (between the intermediate auxiliary plate 498 and the rear partition wall 494). Accordingly, the rotational power of the main transmission input shaft 28 is transmitted to the hydraulic continuously variable transmission 500 via the main transmission input gear 513, the input transmission gear 514, and the input transmission shaft 511. A main transmission high-speed gear 516, a main transmission reverse gear 517, and a main transmission low-speed gear 515 are fitted on the main transmission output shaft 512 so as not to rotate relative to each other for traveling output.
油圧無段変速機500は、可変容量形の油圧ポンプ部521と、当該油圧ポンプ部521から吐出する高圧の作動油によって作動する定容量形の油圧モータ部522とを備えている。油圧ポンプ部521には、入力伝達軸511の軸線に対して傾斜角を変更可能して作動油供給量を調節するポンプ斜板523を設けている。ポンプ斜板523には、入力伝達軸511の軸線に対するポンプ斜板523の傾斜角を変更調節する主変速油圧シリンダ524を連動連結している。実施形態では、油圧無段変速機500に主変速油圧シリンダ524を組み付けていて、一つの部材としてユニット化している。主変速油圧シリンダ524の駆動でポンプ斜板523の傾斜角を変更することによって、油圧ポンプ部521から油圧モータ部522に供給される作動油量を変更調節し、油圧無段変速機500の主変速動作が行われる。
The hydraulic continuously variable transmission 500 includes a variable displacement hydraulic pump unit 521 and a constant displacement hydraulic motor unit 522 that is operated by high-pressure hydraulic oil discharged from the hydraulic pump unit 521. The hydraulic pump unit 521 is provided with a pump swash plate 523 that can change the inclination angle with respect to the axis of the input transmission shaft 511 and adjust the amount of hydraulic oil supplied. A main transmission hydraulic cylinder 524 that changes and adjusts the inclination angle of the pump swash plate 523 with respect to the axis of the input transmission shaft 511 is linked to the pump swash plate 523. In the embodiment, the main transmission hydraulic cylinder 524 is assembled to the hydraulic continuously variable transmission 500 and unitized as one member. By changing the inclination angle of the pump swash plate 523 by driving the main transmission hydraulic cylinder 524, the amount of hydraulic fluid supplied from the hydraulic pump unit 521 to the hydraulic motor unit 522 is changed and adjusted, A speed change operation is performed.
すなわち、主変速レバー50の操作量に比例して主変速油圧シリンダ524を駆動させると、これに伴い入力伝達軸511の軸線に対するポンプ斜板523の傾斜角が変更される。実施形態のポンプ斜板523は、傾斜略零(零を含むその前後)の中立角度を挟んで一方(正)の最大傾斜角度と他方(負)の最大傾斜角度との間の範囲で角度調節可能であり、且つ、走行機体2の車速が最低のときにいずれか一方に傾斜した角度(この場合は負で且つ最大付近の傾斜角度)に設定している。
That is, when the main transmission hydraulic cylinder 524 is driven in proportion to the operation amount of the main transmission lever 50, the inclination angle of the pump swash plate 523 with respect to the axis of the input transmission shaft 511 is changed accordingly. The pump swash plate 523 of the embodiment adjusts the angle in a range between one (positive) maximum inclination angle and the other (negative) maximum inclination angle with a neutral angle of substantially zero inclination (before and after including zero) interposed therebetween. It is possible to set an angle that is inclined to one of the two times when the vehicle speed of the traveling machine body 2 is the lowest (in this case, an inclination angle that is negative and near the maximum).
ポンプ斜板523の傾斜角が略零(中立角度)のときは、油圧ポンプ部521では油圧モータ部522が駆動されず、入力伝達軸511と略同一回転速度にて主変速出力軸512が回転する。入力伝達軸511の軸線に対してポンプ斜板523を一方向(正の傾斜角)側に傾斜させたときは、油圧ポンプ部521が油圧モータ部522を増速作動させ、入力伝達軸511より速い回転速度で主変速出力軸512が回転する。このため、入力伝達軸511の回転速度に油圧モータ部522の回転速度が加算されて、主変速出力軸512に伝達される。その結果、入力伝達軸511の回転速度より高い回転速度の範囲で、ポンプ斜板523の傾斜角(正の傾斜角)に比例して、主変速出力軸512からの変速動力(車速)が変更される。ポンプ斜板523が正で且つ最大付近の傾斜角度のときに、走行機体2は最高車速になる。
When the inclination angle of the pump swash plate 523 is substantially zero (neutral angle), the hydraulic motor unit 522 is not driven by the hydraulic pump unit 521, and the main transmission output shaft 512 rotates at substantially the same rotational speed as the input transmission shaft 511. To do. When the pump swash plate 523 is tilted in one direction (positive tilt angle) with respect to the axis of the input transmission shaft 511, the hydraulic pump unit 521 activates the hydraulic motor unit 522 at a higher speed than the input transmission shaft 511. The main transmission output shaft 512 rotates at a high rotational speed. For this reason, the rotational speed of the hydraulic motor unit 522 is added to the rotational speed of the input transmission shaft 511 and transmitted to the main transmission output shaft 512. As a result, the shift power (vehicle speed) from the main shift output shaft 512 is changed in proportion to the tilt angle (positive tilt angle) of the pump swash plate 523 within a range of rotation speed higher than the rotation speed of the input transmission shaft 511. Is done. When the pump swash plate 523 is positive and has an inclination angle near the maximum, the traveling machine body 2 reaches the maximum vehicle speed.
入力伝達軸511の軸線に対してポンプ斜板523を他方向(負の傾斜角)側に傾斜させたときは、油圧ポンプ部521が油圧モータ部522を減速(逆転)作動させ、入力伝達軸511より低い回転速度で主変速出力軸512が回転する。このため、入力伝達軸511の回転速度から油圧モータ部522の回転速度が減算されて、主変速出力軸512に伝達される。その結果、入力伝達軸511の回転速度より低い回転速度の範囲で、ポンプ斜板523の傾斜角(負の傾斜角)に比例して、主変速出力軸512からの変速動力が変更される。ポンプ斜板523が負で且つ最大付近の傾斜角度のときに、走行機体2は最低車速になる。
When the pump swash plate 523 is tilted in the other direction (negative tilt angle) with respect to the axis of the input transmission shaft 511, the hydraulic pump unit 521 decelerates (reverses) the hydraulic motor unit 522, and the input transmission shaft The main transmission output shaft 512 rotates at a rotational speed lower than 511. For this reason, the rotational speed of the hydraulic motor unit 522 is subtracted from the rotational speed of the input transmission shaft 511 and transmitted to the main transmission output shaft 512. As a result, the speed change power from the main speed change output shaft 512 is changed in proportion to the inclination angle (negative inclination angle) of the pump swash plate 523 within the range of the rotation speed lower than the rotation speed of the input transmission shaft 511. When the pump swash plate 523 is negative and has an inclination angle near the maximum, the traveling machine body 2 has the minimum vehicle speed.
なお、作業機用及び走行用油圧ポンプ481,482の両者を駆動させるポンプ駆動軸483には、ポンプ駆動ギヤ484を相対回転不能に被嵌している。ポンプ駆動ギヤ484は、平ギヤ機構485を介して、主変速入力軸28の主変速入力ギヤ513を動力伝達可能に連結している。また、中間補助プレート498と後部仕切り壁494との間には、油圧無段変速機500や前後進切換機構501等に潤滑用の作動油を供給する潤滑油ポンプ518を配置している。潤滑油ポンプ518のポンプ軸519に固着したポンプギヤ520は入力伝達軸511の入力伝達ギヤ514に常時噛み合っている。従って、作業機用及び走行用油圧ポンプ481,482と潤滑油ポンプ518とは、エンジン5の回転動力によって駆動する。
A pump drive gear 484 is fitted on the pump drive shaft 483 that drives both the working machine and traveling hydraulic pumps 481 and 482 so as not to be relatively rotatable. The pump drive gear 484 connects the main transmission input gear 513 of the main transmission input shaft 28 via a flat gear mechanism 485 so that power can be transmitted. A lubricating oil pump 518 is provided between the intermediate auxiliary plate 498 and the rear partition wall 494 to supply hydraulic oil for lubrication to the hydraulic continuously variable transmission 500, the forward / reverse switching mechanism 501 and the like. The pump gear 520 fixed to the pump shaft 519 of the lubricating oil pump 518 is always meshed with the input transmission gear 514 of the input transmission shaft 511. Therefore, the working machine and traveling hydraulic pumps 481 and 482 and the lubricating oil pump 518 are driven by the rotational power of the engine 5.
次に、前後進切換機構501を介して実行する前進と後進との切換構造について説明する。主変速入力軸28のうち中間室497内の箇所(主変速入力軸28の後部側)に、前進高速ギヤ機構である遊星歯車機構526と、前進低速ギヤ機構である低速ギヤ対525とを配置している。遊星歯車機構526は、主変速入力軸28に回転可能に軸支した入力側伝動ギヤ529と一体的に回転するサンギヤ531、複数の遊星ギヤ533を同一半径上に回転可能に軸支したキャリア532、並びに内周面に内歯を有するリングギヤ534を備えている。サンギヤ531及びリングギヤ534は主変速入力軸28に回転可能に被嵌している。キャリア532は主変速入力軸28に相対回転不能に被嵌している。サンギヤ531はキャリア532の各遊星ギヤ533と半径内側から噛み合っている。また、リングギヤ534の内歯は各遊星ギヤ533と半径外側から噛み合っている。主変速入力軸28には、リングギヤ534と一体回転する出力側伝動ギヤ530も回転可能に軸支している。低速ギヤ対525を構成する入力側低速ギヤ527と出力側低速ギヤ528とは一体構造になっていて、主変速入力軸28のうち遊星歯車機構526と主変速入力ギヤ513との間に回転可能に軸支している。
Next, a forward / backward switching structure executed via the forward / reverse switching mechanism 501 will be described. A planetary gear mechanism 526, which is a forward high-speed gear mechanism, and a low-speed gear pair 525, which is a forward low-speed gear mechanism, are disposed at a location in the intermediate chamber 497 of the main transmission input shaft 28 (on the rear side of the main transmission input shaft 28). is doing. The planetary gear mechanism 526 includes a sun gear 531 that rotates integrally with an input-side transmission gear 529 that is rotatably supported on the main transmission input shaft 28, and a carrier 532 that rotatably supports a plurality of planetary gears 533 on the same radius. And a ring gear 534 having inner teeth on the inner peripheral surface. The sun gear 531 and the ring gear 534 are rotatably fitted on the main transmission input shaft 28. The carrier 532 is fitted to the main transmission input shaft 28 so as not to be relatively rotatable. The sun gear 531 meshes with each planetary gear 533 of the carrier 532 from the inside of the radius. Further, the inner teeth of the ring gear 534 mesh with the planetary gears 533 from the radially outer side. An output side transmission gear 530 that rotates integrally with the ring gear 534 is also rotatably supported on the main transmission input shaft 28. The input-side low-speed gear 527 and the output-side low-speed gear 528 constituting the low-speed gear pair 525 have an integral structure, and can rotate between the planetary gear mechanism 526 and the main transmission input gear 513 of the main transmission input shaft 28. It is pivotally supported.
ミッションケース17の中間室497内(中間ケース114及び後部変速ケース113前側の内部)には、主変速入力軸28、入力伝達軸511及び主変速出力軸512と平行状に延びる走行中継軸535並びに走行伝動軸536を配置している。走行中継軸535の前端側は中間仕切り壁493に回転可能に軸支している。走行中継軸535の後端側は中間補助プレート498に回転可能に軸支している。走行伝動軸536の前端側は中間仕切り壁493に回転可能に軸支している。走行伝動軸536の後端側は中間補助プレート498に回転可能に軸支している。
In the intermediate chamber 497 of the transmission case 17 (inside the intermediate case 114 and the front side of the rear transmission case 113), the main transmission input shaft 28, the input transmission shaft 511, the travel relay shaft 535 extending in parallel with the main transmission output shaft 512, and A travel transmission shaft 536 is disposed. The front end side of the travel relay shaft 535 is rotatably supported by the intermediate partition wall 493. A rear end side of the travel relay shaft 535 is rotatably supported on the intermediate auxiliary plate 498. The front end side of the traveling transmission shaft 536 is rotatably supported by the intermediate partition wall 493. The rear end side of the travel transmission shaft 536 is rotatably supported by the intermediate auxiliary plate 498.
走行中継軸535に前後進切換機構501を設けている。すなわち、走行中継軸535には、湿式多板型の前進高速油圧クラッチ539で連結される前進高速ギヤ540と、湿式多板型の後進油圧クラッチ541で連結される後進ギヤ542と、湿式多板型の前進低速油圧クラッチ537で連結される前進低速ギヤ538とを被嵌している。走行中継軸535のうち前進高速油圧クラッチ539と後進ギヤ542との間には、走行中継ギヤ543を相対回転不能に被嵌している。走行伝動軸536には、走行中継ギヤ543と常時噛み合う走行伝動ギヤ544を相対回転不能に被嵌している。主変速出力軸512の主変速低速ギヤ515が主変速入力軸28側にある低速ギヤ対525の入力側低速ギヤ527と常時噛み合い、出力側低速ギヤ528が前進低速ギヤ538と常時噛み合っている。主変速出力軸512の主変速高速ギヤ516が主変速入力軸28側にある遊星歯車機構526の入力側伝動ギヤ529と常時噛み合い、出力側伝動ギヤ530が前進高速ギヤ540と常時噛み合っている。主変速出力軸512の主変速逆転ギヤ517が後進ギヤ542と常時噛み合っている。
The forward / reverse switching mechanism 501 is provided on the traveling relay shaft 535. That is, the traveling relay shaft 535 has a forward high-speed gear 540 coupled by a wet multi-plate forward high-speed hydraulic clutch 539, a reverse gear 542 coupled by a wet multi-plate reverse hydraulic clutch 541, and a wet multi-plate. A forward low-speed gear 538 connected by a forward low-speed hydraulic clutch 537 of the mold is fitted. A travel relay gear 543 is fitted between the forward high speed hydraulic clutch 539 and the reverse gear 542 in the travel relay shaft 535 so as not to be relatively rotatable. A travel transmission gear 544 that always meshes with the travel relay gear 543 is fitted to the travel transmission shaft 536 so as not to be relatively rotatable. The main transmission low speed gear 515 of the main transmission output shaft 512 is always meshed with the input low speed gear 527 of the low speed gear pair 525 on the main transmission input shaft 28 side, and the output low speed gear 528 is always meshed with the forward low speed gear 538. The main transmission high speed gear 516 of the main transmission output shaft 512 is always meshed with the input transmission gear 529 of the planetary gear mechanism 526 on the main transmission input shaft 28 side, and the output transmission gear 530 is always meshed with the forward high speed gear 540. A main transmission reverse gear 517 of the main transmission output shaft 512 is always meshed with the reverse gear 542.
前後進切換レバー36を前進側に操作すると、前進低速油圧クラッチ537又は前進高速油圧クラッチ539が動力接続状態となり、前進低速ギヤ538又は前進高速ギヤ540と走行中継軸535とが相対回転不能に連結される。その結果、主変速出力軸512から低速ギヤ対525又は遊星歯車機構526を介して走行中継軸535に、前進低速又は前進高速の回転動力が伝達され、走行中継軸535から走行伝動軸536に動力伝達される。前後進切換レバー36を後進側に操作すると、後進油圧クラッチ541が動力接続状態となり、後進ギヤ542と走行中継軸535とが相対回転不能に連結される。その結果、主変速出力軸512から低速ギヤ対525又は遊星歯車機構526を介して走行中継軸535に、後進の回転動力が伝達され、走行中継軸535から走行伝動軸536に動力伝達される。
When the forward / reverse switching lever 36 is operated to the forward side, the forward low-speed hydraulic clutch 537 or the forward high-speed hydraulic clutch 539 is in a power connection state, and the forward low-speed gear 538 or forward high-speed gear 540 and the travel relay shaft 535 are connected to each other so as not to be relatively rotatable. Is done. As a result, forward low-speed or high-speed rotational power is transmitted from the main transmission output shaft 512 to the travel relay shaft 535 via the low-speed gear pair 525 or the planetary gear mechanism 526, and power is transmitted from the travel relay shaft 535 to the travel transmission shaft 536. Communicated. When the forward / reverse switching lever 36 is operated to the reverse side, the reverse hydraulic clutch 541 enters a power connection state, and the reverse gear 542 and the travel relay shaft 535 are coupled so as not to be relatively rotatable. As a result, the reverse rotational power is transmitted from the main transmission output shaft 512 to the travel relay shaft 535 via the low speed gear pair 525 or the planetary gear mechanism 526, and the power is transmitted from the travel relay shaft 535 to the travel transmission shaft 536.
なお、前後進切換レバー36の前進側操作によって、前進低速油圧クラッチ537及び前進高速油圧クラッチ539のどちらが動力接続状態になるかは、主変速レバー50の操作量に応じて決定される。また、前後進切換レバー36が中立位置のときは、全ての油圧クラッチ537,539,541がいずれも動力切断状態となり、主変速出力軸512からの走行駆動力が略零(主クラッチ切りの状態)になる。
It should be noted that which of the forward low-speed hydraulic clutch 537 and the forward high-speed hydraulic clutch 539 is in the power-connected state by the forward operation of the forward / reverse switching lever 36 is determined according to the operation amount of the main transmission lever 50. When the forward / reverse switching lever 36 is in the neutral position, all the hydraulic clutches 537, 539, and 541 are in the power cut state, and the driving force from the main transmission output shaft 512 is substantially zero (the main clutch disengaged state). )become.
次に、走行変速ギヤ機構であるクリープ変速ギヤ機構502及び走行副変速ギヤ機構503を介して実行する超低速と低速と高速との切換構造について説明する。ミッションケースの前室495内(前部変速ケース112内)には、前後進切換機構501を経由した回転動力を変速する機械式のクリープ変速ギヤ機構502及び走行副変速ギヤ機構503を配置している。この場合、前室495内(前部変速ケース112内)に、走行伝動軸536と同軸状に延びる走行カウンタ軸545を配置している。また、前部変速ケース112から後部変速ケース113にわたって(前室495から中間室497を介して後室496にわたって)は、走行カウンタ軸545と平行状に延びる副変速軸546を配置している。走行カウンタ軸545の前端側は前蓋部材491に回転可能に軸支している。走行カウンタ軸545の後端側は中間仕切り壁493に回転可能に支持させている。副変速軸546の前端側は前蓋部材491に回転可能に軸支している。副変速軸546の前後中途部は中間仕切り壁493に回転可能に軸支している。副変速軸546の後端側は中間補助プレート498及び後部仕切り壁494に回転可能に軸支している。
Next, an ultra-low speed, low-speed and high-speed switching structure executed via the creep transmission gear mechanism 502 and the traveling auxiliary transmission gear mechanism 503, which are traveling transmission gear mechanisms, will be described. In the front chamber 495 of the transmission case (in the front transmission case 112), a mechanical creep transmission gear mechanism 502 and a traveling auxiliary transmission gear mechanism 503 for shifting rotational power via the forward / reverse switching mechanism 501 are arranged. Yes. In this case, a travel counter shaft 545 extending coaxially with the travel transmission shaft 536 is disposed in the front chamber 495 (in the front transmission case 112). A sub-transmission shaft 546 extending in parallel with the travel counter shaft 545 is disposed from the front transmission case 112 to the rear transmission case 113 (from the front chamber 495 through the intermediate chamber 497 to the rear chamber 496). The front end side of the travel counter shaft 545 is rotatably supported by the front lid member 491. The rear end side of the travel counter shaft 545 is rotatably supported by the intermediate partition wall 493. The front end side of the auxiliary transmission shaft 546 is rotatably supported by the front lid member 491. The middle part of the auxiliary transmission shaft 546 is rotatably supported by the intermediate partition wall 493. The rear end side of the auxiliary transmission shaft 546 is rotatably supported by the intermediate auxiliary plate 498 and the rear partition wall 494.
走行カウンタ軸545の後部側には伝達ギヤ547とクリープギヤ548とを設けている。伝達ギヤ547は、走行カウンタ軸545に回転可能に被嵌すると共に、走行伝動軸536に一体回転するように連結した状態で中間仕切り壁493に回動可能に軸支している。クリープギヤ548は走行カウンタ軸545に相対回転不能に被嵌している。走行カウンタ軸545のうち伝達ギヤ547とクリープギヤ548との間には、クリープシフタ549を相対回転不能で且つ軸線方向にスライド可能にスプライン嵌合させている。超低速レバー44を入り切り操作することによって、クリープシフタ549がスライド移動して、伝達ギヤ547及びクリープギヤ548が走行カウンタ軸545に択一的に連結される。副変速軸546のうち前室495(前部変速ケース112)内の箇所には、減速ギヤ対550を回転可能に被嵌している。減速ギヤ対550を構成する入力側減速ギヤ551と出力側減速ギヤ552とは一体構造になっていて、走行カウンタ軸545の伝達ギヤ547が副変速軸546の入力側減速ギヤ551に常時噛み合い、クリープギヤ548が出力側減速ギヤ552に常時噛み合っている。
A transmission gear 547 and a creep gear 548 are provided on the rear side of the travel counter shaft 545. The transmission gear 547 is rotatably fitted to the travel counter shaft 545 and is pivotally supported on the intermediate partition wall 493 while being connected to the travel transmission shaft 536 so as to rotate integrally therewith. The creep gear 548 is fitted on the travel counter shaft 545 so as not to be relatively rotatable. A creep shifter 549 is spline-fitted between the transmission gear 547 and the creep gear 548 of the travel counter shaft 545 so as not to be relatively rotatable and slidable in the axial direction. The creep shifter 549 slides by turning the ultra low speed lever 44 on and off, and the transmission gear 547 and the creep gear 548 are alternatively connected to the travel counter shaft 545. A reduction gear pair 550 is rotatably fitted in a portion of the auxiliary transmission shaft 546 in the front chamber 495 (front transmission case 112). The input side reduction gear 551 and the output side reduction gear 552 constituting the reduction gear pair 550 have an integral structure, and the transmission gear 547 of the travel counter shaft 545 always meshes with the input side reduction gear 551 of the auxiliary transmission shaft 546, The creep gear 548 is always meshed with the output side reduction gear 552.
走行カウンタ軸545の前部側には低速中継ギヤ553と高速中継ギヤ554とを設けている。低速中継ギヤ553は走行カウンタ軸545に固着している。高速中継ギヤ554は走行カウンタ軸545に相対回転不能に被嵌している。副変速軸546のうち減速ギヤ対550よりも前部側には、低速中継ギヤ553に噛み合う低速ギヤ555と、高速中継ギヤ554に噛み合う高速ギヤ556とを回転可能に被嵌している。副変速軸546のうち低速ギヤ555と高速ギヤ556との間には、副変速シフタ557を相対回転不能で且つ軸線方向にスライド可能にスプライン嵌合させている。副変速レバー45を操作することによって、副変速シフタ557がスライド移動して、低速ギヤ555及び高速ギヤ556が副変速軸546に択一的に連結される。
A low speed relay gear 553 and a high speed relay gear 554 are provided on the front side of the travel counter shaft 545. The low speed relay gear 553 is fixed to the travel counter shaft 545. The high-speed relay gear 554 is fitted on the travel counter shaft 545 so as not to be relatively rotatable. A low-speed gear 555 that meshes with the low-speed relay gear 553 and a high-speed gear 556 that meshes with the high-speed relay gear 554 are rotatably fitted on the auxiliary transmission shaft 546 on the front side of the reduction gear pair 550. A sub-transmission shifter 557 is spline-fitted between the low-speed gear 555 and the high-speed gear 556 in the sub-transmission shaft 546 so as not to be relatively rotatable and slidable in the axial direction. By operating the sub transmission lever 45, the sub transmission shifter 557 slides and the low speed gear 555 and the high speed gear 556 are alternatively connected to the sub transmission shaft 546.
実施形態では、超低速レバー44を入り操作すると共に副変速レバー45を低速側に操作すると、クリープギヤ548が走行カウンタ軸545に相対回転不能に連結されると共に、低速ギヤ555が副変速軸546に相対回転不能に連結され、走行伝動軸536から走行カウンタ軸545及び副変速軸546を経て、超低速の走行駆動力が前車輪3や後車輪4に向けて出力される。なお、超低速レバー44と副変速レバー45とは、変速牽制部材(詳細は後述する)を介して連動連結していて、副変速レバー45の高速側操作と超低速レバー45の入り操作との両立を禁止するように構成している。すなわち、超低速レバー44を入り操作した状態では副変速レバー45を高速側に操作できず、副変速レバー45を高速側に操作した状態では超低速レバー44を入り操作できないように構成している。
In the embodiment, when the super low speed lever 44 is turned on and the sub transmission lever 45 is operated to the low speed side, the creep gear 548 is connected to the travel counter shaft 545 so as not to be relatively rotatable, and the low speed gear 555 is connected to the sub transmission shaft 546. A relatively low speed travel driving force is output from the travel transmission shaft 536 to the front wheel 3 and the rear wheel 4 via the travel counter shaft 545 and the auxiliary transmission shaft 546. The ultra-low speed lever 44 and the auxiliary transmission lever 45 are interlocked and connected via a shift check member (details will be described later), and the high-speed side operation of the auxiliary transmission lever 45 and the entry operation of the ultra-low speed lever 45 are performed. It is configured to prohibit compatibility. That is, the sub-shift lever 45 cannot be operated to the high speed side when the ultra-low speed lever 44 is operated and the ultra-low speed lever 44 cannot be operated when the sub-speed lever 45 is operated to the high speed side. .
超低速レバー44を切り操作すると共に副変速レバー45を低速側に操作すると、伝達ギヤ547が走行カウンタ軸545に相対回転不能に連結されると共に、低速ギヤ555が副変速軸546に相対回転不能に連結され、走行伝動軸536から走行カウンタ軸545及び副変速軸546を経て、低速の走行駆動力が前車輪3や後車輪4に向けて出力される。超低速レバー44を切り操作すると共に副変速レバー45を高速側に操作すると、伝達ギヤ547が走行カウンタ軸545に相対回転不能に連結されると共に、高速ギヤ556が副変速軸546に相対回転不能に連結され、走行伝動軸536から走行カウンタ軸545及び副変速軸546を経て、高速の走行駆動力が前車輪3や後車輪4に向けて出力される。
When the super low speed lever 44 is turned off and the sub transmission lever 45 is operated to the low speed side, the transmission gear 547 is connected to the travel counter shaft 545 so as not to rotate relative to it, and the low speed gear 555 cannot be rotated relative to the sub transmission shaft 546. And a low-speed traveling driving force is output from the traveling transmission shaft 536 to the front wheels 3 and the rear wheels 4 via the traveling counter shaft 545 and the auxiliary transmission shaft 546. When the super low speed lever 44 is turned off and the sub transmission lever 45 is operated to the high speed side, the transmission gear 547 is connected to the travel counter shaft 545 so as not to rotate relative to it, and the high speed gear 556 cannot be rotated relative to the sub transmission shaft 546. And a high-speed travel driving force is output from the travel transmission shaft 536 to the front wheels 3 and the rear wheels 4 via the travel counter shaft 545 and the auxiliary transmission shaft 546.
副変速軸546の後端側は後部仕切り壁494を貫通して後室496内部にまで延びている。副変速軸546の後端部にはピニオン558を設けている。また、後室496内(後部変速ケース113後側の内部)には、左右の後車輪4に走行駆動力を伝達する後輪用差動ギヤ機構506を配置している。後輪用差動ギヤ機構506には、副変速軸546のピニオン558に噛み合うリングギヤ559と、リングギヤ559に設けた差動ギヤケース560と、左右方向に延びる一対の差動出力軸561とを備えている。差動出力軸561がファイナルギヤ562等を介して後車軸20に連結している。後車軸20の先端側に後車輪4を取り付けている。
The rear end side of the auxiliary transmission shaft 546 passes through the rear partition wall 494 and extends into the rear chamber 496. A pinion 558 is provided at the rear end of the auxiliary transmission shaft 546. Further, in the rear chamber 496 (inside the rear side of the rear transmission case 113), a rear wheel differential gear mechanism 506 for transmitting the driving force to the left and right rear wheels 4 is disposed. The rear wheel differential gear mechanism 506 includes a ring gear 559 that meshes with the pinion 558 of the auxiliary transmission shaft 546, a differential gear case 560 provided in the ring gear 559, and a pair of differential output shafts 561 that extend in the left-right direction. Yes. A differential output shaft 561 is connected to the rear axle 20 via a final gear 562 and the like. The rear wheel 4 is attached to the front end side of the rear axle 20.
左右の差動出力軸561にはブレーキ機構563をそれぞれ配置している。ブレーキ機構563は、ブレーキペダル35及び駐車ブレーキレバー43の操作と自動制御という2つの系統によって、左右の後車輪4にブレーキを掛けるものである。すなわち、各ブレーキ機構563は、ブレーキペダル35の踏み込み操作や駐車ブレーキレバー43の引き上げ操作によって、対応する差動出力軸561ひいては後車輪4にブレーキが掛かるように構成している。操縦ハンドル9の操舵角が所定角度以上になれば、旋回内側の後車輪4に対するオートブレーキ電磁弁631(図14参照)の切換作動によってブレーキシリンダ630(図14参照)が作動し、旋回内側の後車輪4に対するブレーキ機構563が自動的に制動作動するように構成している(いわゆるオートブレーキ)。このため、トラクタ1はUターン(圃場の枕地での方向転換)等の小回り旋回走行を簡単に実行できる。
The left and right differential output shafts 561 are provided with brake mechanisms 563, respectively. The brake mechanism 563 applies brakes to the left and right rear wheels 4 by two systems of operation and automatic control of the brake pedal 35 and the parking brake lever 43. That is, each brake mechanism 563 is configured such that the brake is applied to the corresponding differential output shaft 561 and the rear wheel 4 when the brake pedal 35 is depressed or the parking brake lever 43 is pulled up. When the steering angle of the steering wheel 9 is equal to or greater than a predetermined angle, the brake cylinder 630 (see FIG. 14) is actuated by the switching operation of the autobrake solenoid valve 631 (see FIG. 14) with respect to the rear wheel 4 on the inside of the turn. The brake mechanism 563 for the rear wheel 4 is configured to automatically perform a braking operation (so-called autobrake). For this reason, the tractor 1 can easily execute a small turning turn such as a U-turn (direction change at a headland in a field).
なお、後輪用差動ギヤ機構506には、自身の差動を停止(左右の差動出力軸561を常時等速で駆動)させるデフロック機構585を設けている。デフロックペダル47の踏み込み操作によって、デフロック機構585を構成するデフロックピンを差動ギヤケース560の差動ギヤに係合させると、差動ギヤが差動ギヤケース560に固定され、差動ギヤの差動機能が停止し、左右の差動出力軸561が等速で駆動する。
The differential gear mechanism 506 for the rear wheels is provided with a differential lock mechanism 585 that stops its own differential (the left and right differential output shafts 561 are always driven at a constant speed). When the differential lock pin constituting the differential lock mechanism 585 is engaged with the differential gear of the differential gear case 560 by depressing the differential lock pedal 47, the differential gear is fixed to the differential gear case 560, and the differential function of the differential gear is determined. Stops, and the left and right differential output shafts 561 are driven at a constant speed.
次に、二駆四駆切換機構504を介して実行する前後車輪3,4の二駆と四駆との切換構造について説明する。ミッションケースの前室495(前部変速ケース112)内には二駆四駆切換機構504を配置している。この場合、前室495内(前部変速ケース112内)に、走行カウンタ軸545や副変速軸546と平行状に延びる前車輪入力軸568及び前車輪出力軸30を配置している。副変速軸546の前端側に相対回転不能に被嵌した主動ギヤ569に、前車輪入力軸568に相対回転不能に被嵌した従動ギヤ570を常時噛み合わせている。前車輪入力軸568には、倍速中継ギヤ571と四駆中継ギヤ572とを、従動ギヤ570を挟んだ前後両側に振り分けて相対回転不能に被嵌している。
Next, the switching structure between the two-wheel drive and the four-wheel drive of the front and rear wheels 3 and 4 executed through the two-wheel drive and four-wheel drive switching mechanism 504 will be described. A two-wheel drive / four-wheel drive switching mechanism 504 is disposed in the front chamber 495 (front transmission case 112) of the mission case. In this case, a front wheel input shaft 568 and a front wheel output shaft 30 extending in parallel with the travel counter shaft 545 and the auxiliary transmission shaft 546 are disposed in the front chamber 495 (in the front transmission case 112). A driven gear 569 fitted to the front wheel input shaft 568 so as not to rotate relative to the main drive gear 569 fitted so as not to rotate relative to the front end side of the auxiliary transmission shaft 546 is always meshed. A double-speed relay gear 571 and a four-wheel drive relay gear 572 are fitted to the front wheel input shaft 568 so as not to rotate relative to each other on both sides of the driven gear 570.
前車輪出力軸30に二駆四駆切換機構504を設けている。すなわち、前車輪出力軸30には、湿式多板型の倍速油圧クラッチ573で連結される倍速ギヤ574と、湿式多板型の四駆油圧クラッチ575で連結される四駆ギヤ576とを被嵌している。前車輪入力軸568の倍速中継ギヤ571が前車輪出力軸30の倍速ギヤ574と常時噛み合い、四駆中継ギヤ572が四駆ギヤ576と噛み合っている。
The front wheel output shaft 30 is provided with a 2WD 4WD switching mechanism 504. That is, the front wheel output shaft 30 is fitted with a double speed gear 574 connected by a wet multi-plate type double-speed hydraulic clutch 573 and a four-wheel drive gear 576 connected by a wet multi-plate type four-wheel hydraulic clutch 575. is doing. The double speed relay gear 571 of the front wheel input shaft 568 is always meshed with the double speed gear 574 of the front wheel output shaft 30, and the four-wheel drive relay gear 572 is meshed with the four-wheel gear 576.
駆動切換スイッチ又は駆動切換レバー(図示省略)を四駆側に操作すると、四駆油圧クラッチ575が動力接続状態となり、前車輪出力軸30と四駆ギヤ576とが相対回転不能に連結される。そして、副変速軸546から前車輪入力軸568及び四駆ギヤ576を経由して前車輪出力軸30に回転動力が伝達される結果、トラクタ1は後車輪4と共に前車輪3が駆動する四輪駆動状態になる。また、操縦ハンドル9をUターン操作等して操舵角が所定角度以上になると、倍速油圧クラッチ573が動力接続状態となり、前車輪出力軸30と倍速ギヤ574とが相対回転不能に連結される。そして、副変速軸546から前車輪入力軸568及び倍速ギヤ574を経由して前車輪出力軸30に回転動力が伝達される結果、四駆ギヤ576経由の回転動力による前車輪3の回転速度に比べて約二倍の高速度で、前車輪3が駆動する。
When a drive changeover switch or drive changeover lever (not shown) is operated to the four-wheel drive side, the four-wheel drive hydraulic clutch 575 is in a power connection state, and the front wheel output shaft 30 and the four-wheel drive gear 576 are connected so as not to be relatively rotatable. Then, as a result of the rotational power being transmitted from the auxiliary transmission shaft 546 to the front wheel output shaft 30 via the front wheel input shaft 568 and the four-wheel drive gear 576, the tractor 1 is a four-wheeled vehicle driven by the front wheel 3 together with the rear wheel 4. It becomes a driving state. When the steering handle 9 is operated to make a U-turn or the like and the steering angle becomes equal to or greater than a predetermined angle, the double speed hydraulic clutch 573 is in a power connection state, and the front wheel output shaft 30 and the double speed gear 574 are connected so as not to be relatively rotatable. Then, the rotational power is transmitted from the auxiliary transmission shaft 546 to the front wheel output shaft 30 via the front wheel input shaft 568 and the double speed gear 574, so that the rotational speed of the front wheel 3 by the rotational power via the four-wheel drive gear 576 is increased. The front wheel 3 is driven at a high speed about twice as high.
前車軸ケース13から後ろ向きに突出する前車輪伝達軸508と、前記ミッションケース17(前蓋部材491)の前面下部から前向きに突出する前車輪出力軸30とを、前車輪3に動力を伝達する前車輪駆動軸31によって連結している。前車軸ケース13内には、左右の前車輪3に走行駆動力を伝達する前輪用差動ギヤ機構507を配置している。前輪用差動ギヤ機構507には、前車輪伝達軸508前端側に設けたピニオン577に噛み合うリングギヤ578と、リングギヤ578に設けた差動ギヤケース579と、左右方向に延びる一対の差動出力軸580とを備えている。差動出力軸580がファイナルギヤ581等を介して前車軸16に連結している。前車軸16の先端側に前車輪3を取り付けている。なお、前車軸ケース13の外側面には、操縦ハンドル9の操舵操作によって前車輪3の走行方向を左右に変更するパワーステアリング用の操舵油圧シリンダ622(図14参照)を設けている。
Power is transmitted to the front wheels 3 through the front wheel transmission shaft 508 projecting rearward from the front axle case 13 and the front wheel output shaft 30 projecting forward from the lower front surface of the transmission case 17 (front lid member 491). The front wheel drive shaft 31 is connected. In the front axle case 13, a front wheel differential gear mechanism 507 that transmits a driving force to the left and right front wheels 3 is disposed. The front wheel differential gear mechanism 507 includes a ring gear 578 that meshes with a pinion 577 provided on the front end side of the front wheel transmission shaft 508, a differential gear case 579 provided on the ring gear 578, and a pair of differential output shafts 580 extending in the left-right direction. And. A differential output shaft 580 is connected to the front axle 16 via a final gear 581 or the like. The front wheel 3 is attached to the front end side of the front axle 16. A steering hydraulic cylinder 622 (see FIG. 14) for power steering is provided on the outer surface of the front axle case 13 to change the traveling direction of the front wheel 3 to the left and right by the steering operation of the steering handle 9.
次に、PTO変速機構505を介して実行するPTO軸25の駆動速度の切換構造(正転三段及び逆転一段)について説明する。ミッションケース17の後室496内(後部変速ケース113後側の内部)には、エンジン5からの動力をPTO軸25に伝達するPTO変速機構505を配置している。この場合、主変速入力軸28の後端側に、動力伝達継断用のPTO油圧クラッチ590を介して、主変速入力軸28と同軸状に延びるPTO入力軸591を連結している。PTO入力軸591は後室496内に配置している。この場合、PTO入力軸591の前端側は後部仕切り壁494に回転可能に軸支している。図20に示すように、後室496内には、後室496を前後に区画する上下の支持壁部613,614を一体的に形成している。PTO入力軸591の前後中途部は、後室496内の上支持壁部613に回転可能に軸支している。PTO入力軸591の後端側は後蓋部材492の内面側に回転可能に軸支している。
Next, the drive speed switching structure (three forward rotations and one reverse rotation) of the PTO shaft 25 executed via the PTO transmission mechanism 505 will be described. A PTO transmission mechanism 505 that transmits power from the engine 5 to the PTO shaft 25 is disposed in the rear chamber 496 of the transmission case 17 (inside the rear side of the rear transmission case 113). In this case, a PTO input shaft 591 extending coaxially with the main transmission input shaft 28 is connected to the rear end side of the main transmission input shaft 28 via a PTO hydraulic clutch 590 for power transmission interruption. The PTO input shaft 591 is disposed in the rear chamber 496. In this case, the front end side of the PTO input shaft 591 is rotatably supported on the rear partition wall 494. As shown in FIG. 20, upper and lower support wall portions 613 and 614 that partition the rear chamber 496 forward and backward are integrally formed in the rear chamber 496. A midway portion between the front and rear of the PTO input shaft 591 is rotatably supported on the upper support wall portion 613 in the rear chamber 496. The rear end side of the PTO input shaft 591 is rotatably supported on the inner surface side of the rear cover member 492.
後室496内には、PTO入力軸591と平行状に延びるPTO変速軸592、PTOカウンタ軸593及びPTO軸25を配置している。PTO変速軸592の前端側は上支持壁部613に回転可能に軸支し、PTO変速軸592の後端側は後蓋部材492の内面側に回転可能に軸支している。PTOカウンタ軸593の前端側は下支持壁部614に回転可能に軸支し、PTOカウンタ軸593の後端側は後蓋部材492の内面側に回転可能に軸支している。PTO軸25は後蓋部材492から後方に突出している。PTO軸25の前端側は下支持壁部614に回転可能に軸支している。
In the rear chamber 496, a PTO transmission shaft 592, a PTO counter shaft 593, and a PTO shaft 25 extending in parallel with the PTO input shaft 591 are disposed. The front end side of the PTO transmission shaft 592 is rotatably supported on the upper support wall 613, and the rear end side of the PTO transmission shaft 592 is rotatably supported on the inner surface side of the rear lid member 492. The front end side of the PTO counter shaft 593 is rotatably supported on the lower support wall portion 614, and the rear end side of the PTO counter shaft 593 is rotatably supported on the inner surface side of the rear lid member 492. The PTO shaft 25 protrudes rearward from the rear lid member 492. A front end side of the PTO shaft 25 is rotatably supported on the lower support wall portion 614.
PTOクラッチスイッチ53を動力接続操作すると、PTO油圧クラッチ590が動力接続状態となって、主変速入力軸28とPTO入力軸591とが相対回転不能に連結される。その結果、主変速入力軸28からPTO入力軸591に向かって回転動力が伝達される。
When the power connection operation of the PTO clutch switch 53 is performed, the PTO hydraulic clutch 590 is in a power connection state, and the main transmission input shaft 28 and the PTO input shaft 591 are coupled so as not to be relatively rotatable. As a result, rotational power is transmitted from the main transmission input shaft 28 toward the PTO input shaft 591.
PTO入力軸591には、前側から順に、中速入力ギヤ597、低速入力ギヤ595、高速入力ギヤ596及び逆転シフタギヤ598を設けている。中速入力ギヤ597、低速入力ギヤ595及び高速入力ギヤ596は、PTO入力軸591に相対回転不能に被嵌している。逆転シフタギヤ598は、PTO入力軸591に相対回転不能で且つ軸線方向にスライド可能にスプライン嵌合している。
The PTO input shaft 591 is provided with a medium speed input gear 597, a low speed input gear 595, a high speed input gear 596, and a reverse shifter gear 598 in order from the front side. The medium-speed input gear 597, the low-speed input gear 595, and the high-speed input gear 596 are fitted on the PTO input shaft 591 so as not to be relatively rotatable. The reverse shifter gear 598 is spline-fitted to the PTO input shaft 591 so as not to rotate relative to the PTO input shaft 591 and to be slidable in the axial direction.
一方、PTO変速軸592には、中速入力ギヤ597に噛み合うPTO中速ギヤ601、低速入力ギヤ595に噛み合うPTO低速ギヤ599、及び高速入力ギヤ596に噛み合うPTO高速ギヤ600を回転可能に被嵌している。PTO変速軸592には、前後一対のPTO変速シフタ602,603を相対回転不能で且つ軸線方向にスライド可能にスプライン嵌合している。第一PTO変速シフタ602はPTO中速ギヤ601とPTO低速ギヤ599との間に配置している。第二PTO変速シフタ603はPTO高速ギヤ600よりも後端側に配置している。前後一対のPTO変速シフタ602,603は、PTO変速レバー46の操作に伴い連動して軸線方向にスライド移動するように構成している。PTO変速軸592のうちPTO低速ギヤ599とPTO高速ギヤ600との間にPTO伝動ギヤ604を固着している。
On the other hand, the PTO transmission shaft 592 is rotatably fitted with a PTO medium speed gear 601 that meshes with the medium speed input gear 597, a PTO low speed gear 599 that meshes with the low speed input gear 595, and a PTO high speed gear 600 that meshes with the high speed input gear 596. is doing. A pair of front and rear PTO transmission shifters 602 and 603 are spline-fitted to the PTO transmission shaft 592 so as not to be relatively rotatable and to be slidable in the axial direction. The first PTO shift shifter 602 is disposed between the PTO medium speed gear 601 and the PTO low speed gear 599. The second PTO speed shifter 603 is disposed on the rear end side with respect to the PTO high speed gear 600. The pair of front and rear PTO shift shifters 602 and 603 are configured to slide in the axial direction in conjunction with the operation of the PTO shift lever 46. A PTO transmission gear 604 is fixed between the PTO low-speed gear 599 and the PTO high-speed gear 600 in the PTO transmission shaft 592.
PTOカウンタ軸593には、PTO伝動ギヤ604に噛み合うPTOカウンタギヤ605と、PTO軸25に相対回転不能に被嵌したPTO出力ギヤ608に噛み合うPTO中継ギヤ606と、PTO逆転ギヤ607とを相対回転不能に被嵌している。PTO変速レバー46を中立操作した状態で副PTOレバー48を入り操作することによって、逆転シフタギヤ598がスライド移動して、逆転シフタギヤ598とPTOカウンタ軸593のPTO逆転ギヤ607とが噛み合うように構成している。
The PTO counter shaft 593 has a PTO counter gear 605 that meshes with the PTO transmission gear 604, a PTO relay gear 606 that meshes with a PTO output gear 608 that is non-rotatably fitted to the PTO shaft 25, and a PTO reverse gear 607. It is impossible to fit. When the sub-PTO lever 48 is engaged with the PTO speed change lever 46 in a neutral state, the reverse shifter gear 598 slides and the reverse shifter gear 598 meshes with the PTO reverse gear 607 of the PTO counter shaft 593. ing.
PTO変速レバー46を変速操作すると、前後一対のPTO変速シフタ602,603がPTO変速軸592に沿ってスライド移動し、PTO低速ギヤ595、PTO中速ギヤ597、及びPTO高速ギヤ596がPTO変速軸592に択一的に連結される。その結果、低速~高速の各PTO変速出力が、PTO変速軸592からPTO伝動ギヤ604及びPTOカウンタギヤ605を介してPTOカウンタ軸593に伝達され、更に、PTO中継ギヤ607及びPTO出力ギヤ608を介してPTO軸25に伝達される。
When the PTO speed change lever 46 is operated to shift, the pair of front and rear PTO speed shifters 602 and 603 slide along the PTO speed change shaft 592, and the PTO low speed gear 595, the PTO medium speed gear 597, and the PTO high speed gear 596 become the PTO speed change shaft. 592 is alternatively connected. As a result, low-speed to high-speed PTO shift outputs are transmitted from the PTO shift shaft 592 to the PTO counter shaft 593 via the PTO transmission gear 604 and the PTO counter gear 605, and further, the PTO relay gear 607 and the PTO output gear 608 are transmitted. Is transmitted to the PTO shaft 25.
副PTOレバー48を入り操作すると、逆転シフタギヤ598がPTO逆転ギヤ607と噛み合い、PTO入力軸591の回転動力が、逆転シフタギヤ598及びPTO逆転ギヤ607を介してPTOカウンタ軸593に伝達される。そして、逆転のPTO変速出力が、PTOカウンタ軸593からPTO中継ギヤ607及びPTO出力ギヤ608を介してPTO軸25に伝達される。
When the sub PTO lever 48 is turned on and operated, the reverse shifter gear 598 meshes with the PTO reverse gear 607, and the rotational power of the PTO input shaft 591 is transmitted to the PTO counter shaft 593 via the reverse shifter gear 598 and the PTO reverse gear 607. Then, the reverse PTO shift output is transmitted from the PTO counter shaft 593 to the PTO shaft 25 via the PTO relay gear 607 and the PTO output gear 608.
上記の説明から明らかなように、実施形態のPTO変速機構505は、後室496のうち上下支持壁部613,614よりも後方側に位置している。後室496のうち上下支持壁部613,614よりも前方側に、後輪用差動ギヤ機構506を配置している。このように実施形態では、ミッションケース17の後室496内に、後輪用差動ギヤ機構506とPTO変速機構505(PTO伝動系統)とを選り分けして簡単且つコンパクトに配置して、前記ミッションケース17の組み立て作業性並びにメンテナンス性の向上を図っている。
As is clear from the above description, the PTO speed change mechanism 505 of the embodiment is located behind the upper and lower support wall portions 613 and 614 in the rear chamber 496. A rear wheel differential gear mechanism 506 is disposed in front of the upper and lower support wall portions 613 and 614 in the rear chamber 496. Thus, in the embodiment, in the rear chamber 496 of the mission case 17, the rear wheel differential gear mechanism 506 and the PTO transmission mechanism 505 (PTO transmission system) are selected and arranged in a simple and compact manner. The assembling workability and maintainability of the case 17 are improved.
また、PTO軸25等の各軸25,591,592,593の軸支構造からも明らかなように、ミッションケース17の後面開口部を着脱可能に塞ぐ後蓋部材492を着脱することによって、後室496のうち上下支持壁部613,614よりも後方側にPTO変速機構505を出入可能に構成している。そして、後室496のうち上下支持壁部613,614よりも後方側にPTO変速機構505を装着した状態では、上下支持壁部613,614と後蓋部材492とによってPTO変速機構505を支持している。このため、ミッションケース17から後蓋部材492を取り外せば、PTO変速機構505を露出できることになる。従って、ミッションケース17の組み立て作業性及び分解作業性、PTO変速機構505のメンテナンス性の更なる向上を図れる。
Further, as is apparent from the shaft support structure of each of the shafts 25, 591, 592, 593 such as the PTO shaft 25, the rear cover member 492 that detachably closes the rear opening of the transmission case 17 can be attached and detached to remove the rear cover member 492. The PTO speed change mechanism 505 is configured to be able to enter and leave the chamber 496 behind the upper and lower support walls 613 and 614. When the PTO transmission mechanism 505 is mounted on the rear side of the rear chamber 496 from the upper and lower support wall portions 613 and 614, the PTO transmission mechanism 505 is supported by the upper and lower support wall portions 613 and 614 and the rear lid member 492. ing. For this reason, if the rear cover member 492 is removed from the mission case 17, the PTO transmission mechanism 505 can be exposed. Therefore, the assembly workability and disassembly workability of the mission case 17 and the maintenance performance of the PTO transmission mechanism 505 can be further improved.
実施形態では、上支持壁部613と後蓋部材492とによってPTO入力軸591及びPTO変速軸592を軸支し、下支持壁部614と後蓋部材492とによってPTOカウンタ軸593及びPTO軸25を軸支している。そして、これら各軸25,591~593の位置関係を背面視で矩形の頂点に位置するように設定し(図21参照)、上段のPTO入力軸591から中段のPTO変速軸592及びPTOカウンタ軸593を経て下段のPTO軸25に、PTO出力を伝達するように構成している。このように構成すると、PTO出力の高出力化に伴う各軸25,591~593の反力を相殺し合うことが可能になる。その結果、ミッションケース17及び走行機体2への振動伝達を軽減できる。
In the embodiment, the PTO input shaft 591 and the PTO transmission shaft 592 are supported by the upper support wall portion 613 and the rear cover member 492, and the PTO counter shaft 593 and the PTO shaft 25 are supported by the lower support wall portion 614 and the rear cover member 492. Is supported. Then, the positional relationship between these shafts 25, 591 to 593 is set so as to be positioned at the top of a rectangle in a rear view (see FIG. 21), and the upper PTO input shaft 591 to the middle PTO speed change shaft 592 and the PTO counter shaft. The PTO output is transmitted to the lower PTO shaft 25 via 593. With this configuration, the reaction forces of the shafts 25, 591 to 593 accompanying the increase in PTO output can be offset. As a result, vibration transmission to the mission case 17 and the traveling machine body 2 can be reduced.
なお、後部変速ケース113内には、中間室497から後室496にわたって、副変速軸546と平行状に延びる前後長手の車速同調軸564を配置している。車速同調軸564の前端側には車速同調入力ギヤ565を相対回転不能に被嵌している。車速同調入力ギヤ565は、副変速軸546のうち中間室497内の箇所に相対回転不能に被嵌した動力分岐ギヤ566と常時噛み合っている。PTO軸25のうちPTO出力ギヤ608よりも前部側に回転可能に被嵌した車速同調出力ギヤ610には、車速同調軸564の後端部に固着した車速同調中継ギヤ609と常時噛み合っている。PTO軸25のうち車速同調出力ギヤ610とPTO出力ギヤ608との間には、車速同調シフタ611を相対回転不能で且つ軸線方向にスライド可能にスプライン嵌合させている。PTO変速レバー46を中立操作した状態で副PTOレバー48を入り操作することによって、車速同調シフタ611がスライド移動して、車速同調出力ギヤ610がPTO軸25に連結される。その結果、副変速軸546から車速同調軸564を経由した車速同調出力がPTO軸25に伝達される。
In the rear transmission case 113, a longitudinal longitudinal vehicle speed tuning shaft 564 extending in parallel with the auxiliary transmission shaft 546 is disposed from the intermediate chamber 497 to the rear chamber 496. A vehicle speed tuning input gear 565 is fitted on the front end side of the vehicle speed tuning shaft 564 so as not to be relatively rotatable. The vehicle speed tuning input gear 565 is always meshed with a power branch gear 566 that is fitted in a position in the intermediate chamber 497 of the auxiliary transmission shaft 546 so as not to be relatively rotatable. A vehicle speed tuning output gear 610 that is rotatably fitted to the front side of the PTO output gear 608 in the PTO shaft 25 is always meshed with a vehicle speed tuning relay gear 609 fixed to the rear end portion of the vehicle speed tuning shaft 564. . A vehicle speed tuning shifter 611 is spline-fitted between the vehicle speed tuning output gear 610 and the PTO output gear 608 of the PTO shaft 25 so as not to be relatively rotatable and slidable in the axial direction. When the sub PTO lever 48 is turned on while the PTO speed change lever 46 is operated in a neutral state, the vehicle speed tuning shifter 611 slides and the vehicle speed tuning output gear 610 is connected to the PTO shaft 25. As a result, the vehicle speed tuning output from the auxiliary transmission shaft 546 via the vehicle speed tuning shaft 564 is transmitted to the PTO shaft 25.
ここで、実施形態では、PTO軸25の駆動仕様に応じて副PTOレバー48の機能を異ならせている。すなわち、PTO軸25を逆転駆動可能にする仕様では、副PTOレバー48の手動操作によって逆転シフタギヤ598をスライド移動させ、逆転のPTO変速出力をPTO軸25に伝達するように構成している。PTO軸25を車速同調駆動させる仕様では、副PTOレバー48の手動操作によって車速同調シフタ611をスライド移動させ、車速に同調したPTO変速出力をPTO軸25に伝達するように構成している。
Here, in the embodiment, the function of the sub PTO lever 48 is made different depending on the drive specification of the PTO shaft 25. In other words, in the specification that allows the PTO shaft 25 to be driven in reverse, the reverse shifter gear 598 is slid by manual operation of the sub PTO lever 48 and the reverse PTO shift output is transmitted to the PTO shaft 25. In the specification for driving the PTO shaft 25 in synchronization with the vehicle speed, the vehicle speed synchronization shifter 611 is slid by manual operation of the sub-PTO lever 48, and the PTO shift output synchronized with the vehicle speed is transmitted to the PTO shaft 25.
なお、いずれの仕様においても、PTO変速レバー46と副PTOレバー48とはPTO牽制部材(詳細は後述する)を介して連動連結していて、PTO変速レバー46の中立以外の変速操作と副PTOレバー48の入り操作との両立を禁止するように構成している。すなわち、副PTOレバー48を入り操作した状態ではPTO変速レバー46を中立以外に変速操作できず、PTO変速レバー46を中立以外に変速操作した状態では副PTOレバー48を入り操作できないように構成している。
In any of the specifications, the PTO speed change lever 46 and the sub PTO lever 48 are interlocked and connected via a PTO check member (details will be described later). It is configured to prohibit compatibility with the lever 48 entering operation. In other words, the PTO speed change lever 46 cannot be shifted to any position other than neutral when the sub PTO lever 48 is engaged, and the sub PTO lever 48 cannot be engaged when the speed change operation is performed other than neutral. ing.
次に、図14を参照しながら、トラクタ1の油圧回路620構造について説明する。トラクタ1の油圧回路620は、エンジン5の回転動力によって駆動する作業機用油圧ポンプ481及び走行用油圧ポンプ482を備えている。実施形態では、ミッションケース17が作業油タンクとして利用されていて、ミッションケース17内の作動油が作業機用油圧ポンプ481及び走行用油圧ポンプ482に供給される。走行用油圧ポンプ482は、パワーステアリング用のコントロール弁機構621を介して操縦ハンドル9によるパワーステアリング用の操舵油圧シリンダ622に接続すると共に、油圧無段変速機500の油圧ポンプ521と油圧モータ522とをつなぐ閉ループ油路623に接続している。エンジン5の駆動中は、走行用油圧ポンプ482からの作動油が閉ループ油路623に常に補充される。
Next, the structure of the hydraulic circuit 620 of the tractor 1 will be described with reference to FIG. The hydraulic circuit 620 of the tractor 1 includes a working machine hydraulic pump 481 and a traveling hydraulic pump 482 that are driven by the rotational power of the engine 5. In the embodiment, the mission case 17 is used as a working oil tank, and the working oil in the mission case 17 is supplied to the working machine hydraulic pump 481 and the traveling hydraulic pump 482. The traveling hydraulic pump 482 is connected to the steering hydraulic cylinder 622 for power steering by the steering handle 9 via the control valve mechanism 621 for power steering, and the hydraulic pump 521 and the hydraulic motor 522 of the hydraulic continuously variable transmission 500. Is connected to a closed loop oil passage 623 connecting the two. While the engine 5 is being driven, the hydraulic oil from the traveling hydraulic pump 482 is always replenished to the closed loop oil passage 623.
また、走行用油圧ポンプ482は、油圧無段変速機500の主変速油圧シリンダ524に対する主変速油圧切換弁624と、倍速油圧クラッチ573に対する倍速油圧切換弁625と、四駆油圧クラッチ575に対する四駆油圧切換弁626と、PTO油圧クラッチ590に対するPTOクラッチ電磁弁627及びこれによって作動する切換弁628とに接続している。
The traveling hydraulic pump 482 includes a main transmission hydraulic switching valve 624 for the main transmission hydraulic cylinder 524 of the hydraulic continuously variable transmission 500, a double speed hydraulic switching valve 625 for the double speed hydraulic clutch 573, and a four-wheel drive for the four-wheel hydraulic clutch 575. The hydraulic switching valve 626 is connected to a PTO clutch electromagnetic valve 627 for the PTO hydraulic clutch 590 and a switching valve 628 operated thereby.
更に、走行用油圧ポンプ482は、左右一対のオートブレーキ用のブレーキシリンダ630をそれぞれ作動させる切換弁としての左右のオートブレーキ電磁弁631と、前進低速油圧クラッチ537を作動させる前進低速クラッチ電磁弁632と、前進高速油圧クラッチ539を作動させる前進高速クラッチ電磁弁633と、後進油圧クラッチ541を作動させる後進クラッチ電磁弁634と、前記各クラッチ電磁弁632~634への作動油供給を制御するマスター制御電磁弁635とに接続している。
Further, the traveling hydraulic pump 482 includes left and right autobrake solenoid valves 631 as switching valves that actuate a pair of left and right autobrake brake cylinders 630, and a forward low speed clutch solenoid valve 632 that actuates a forward low speed hydraulic clutch 537. A forward high-speed clutch electromagnetic valve 633 for operating the forward high-speed hydraulic clutch 539, a reverse clutch electromagnetic valve 634 for operating the reverse hydraulic clutch 541, and master control for controlling hydraulic oil supply to the clutch electromagnetic valves 632 to 634 It is connected to the electromagnetic valve 635.
作業機用油圧ポンプ481は、ミッションケース17の上面後部側にある油圧式昇降機構22の上面に積層配置した複数の油圧外部取出バルブ430と、左右後車輪4間のトレッド(車輪間距離)を調節する左右のトレッド調節油圧シリンダ645への作動油供給を制御する左右のトレッド調節電磁弁646と、右リフトロッド121に設けた水平シリンダ122への作動油供給を制御する傾斜制御電磁弁647と、油圧式昇降機構22における油圧リフトシリンダ117への作動油供給を制御する上昇油圧切換弁648及び下降油圧切換弁649と、上昇油圧切換弁648を切換作動させる上昇制御電磁弁650と、下降油圧切換弁649を作動させる下降制御電磁弁651とに接続している。
The work machine hydraulic pump 481 is configured to provide a tread (distance between wheels) between a plurality of hydraulic external extraction valves 430 arranged on the upper surface of the hydraulic lifting mechanism 22 on the rear side of the upper surface of the mission case 17 and the left and right rear wheels 4. Left and right tread adjustment solenoid valves 646 that control the supply of hydraulic oil to the right and left tread adjustment hydraulic cylinders 645, and a tilt control solenoid valve 647 that controls the supply of hydraulic oil to the horizontal cylinder 122 provided on the right lift rod 121 , An ascending oil pressure switching valve 648 and a descending oil pressure switching valve 649 for controlling the supply of hydraulic oil to the hydraulic lift cylinder 117 in the hydraulic lifting mechanism 22, an ascending control electromagnetic valve 650 for switching the ascending oil pressure switching valve 648, and a descending oil pressure The switching valve 649 is connected to a lowering control electromagnetic valve 651 for operating.
左右のトレッド調節電磁弁646を切換駆動させると、左右のトレッド調節油圧シリンダ645が伸縮動して左右の後車軸ケース19を左右方向に伸縮動させる。その結果、左右後車輪4間のトレッドが長くなったり短くなったりする。傾斜制御電磁弁647を切換駆動させると、水平シリンダ122が伸縮動して、前部側にあるロワーリンクピンを支点にして右側のロワーリンク23が上下動する。その結果、左右両ロワーリンク23を介して対地作業機が走行機体2に対して左右に傾動し、対地作業機の左右傾斜角度が変化する。上昇制御電磁弁650によって上昇油圧切換弁648を切換作動させるか又は下降制御電磁弁651によって下降油圧切換弁649を切換作動させると、油圧リフトシリンダ117が伸縮動し、リフトアーム120及び左右両ロワーリンク23が共に上下動する。その結果、対地作業機が昇降動し、対地作業機の昇降高さ位置が変化する。
When the left and right tread adjustment electromagnetic valves 646 are switched and driven, the left and right tread adjustment hydraulic cylinders 645 expand and contract to expand and contract the left and right rear axle cases 19 in the left and right directions. As a result, the tread between the left and right rear wheels 4 becomes longer or shorter. When the tilt control electromagnetic valve 647 is switched and driven, the horizontal cylinder 122 expands and contracts, and the right lower link 23 moves up and down with the lower link pin on the front side as a fulcrum. As a result, the ground work machine tilts left and right with respect to the traveling machine body 2 via the left and right lower links 23, and the left and right tilt angles of the ground work machine change. When the raising hydraulic switching valve 648 is switched by the raising control electromagnetic valve 650 or the lowering hydraulic switching valve 649 is switched by the lowering control electromagnetic valve 651, the hydraulic lift cylinder 117 expands and contracts, and the lift arm 120 and both the left and right lowers are moved. Both links 23 move up and down. As a result, the ground work machine moves up and down, and the height position of the ground work machine changes.
トラクタ1の油圧回路620は、前述の作業機用油圧ポンプ481及び走行用油圧ポンプ482以外に、エンジン5の回転動力で駆動する潤滑油ポンプ518も備えている。潤滑油ポンプ518には、PTO油圧クラッチ590の潤滑部に作動油(潤滑油)を供給するPTOクラッチ油圧切換弁641と、油圧無段変速機500を軸支する入力伝達軸511の潤滑部と、前進低速油圧クラッチ537の潤滑部に作動油(潤滑油)を供給する前進低速クラッチ油圧切換弁642と、前進高速油圧クラッチ539の潤滑部に作動油(潤滑油)を供給する前進高速クラッチ油圧切換弁643と、後進油圧クラッチ541の潤滑部に作動油(潤滑油)を供給する後進クラッチ油圧切換弁644とに接続している。なお、油圧回路620には、リリーフ弁や流量調整弁、チェック弁、オイルクーラ、オイルフィルタ等を備えている。
The hydraulic circuit 620 of the tractor 1 includes a lubricating oil pump 518 that is driven by the rotational power of the engine 5 in addition to the working machine hydraulic pump 481 and the traveling hydraulic pump 482 described above. The lubricating oil pump 518 includes a PTO clutch hydraulic pressure switching valve 641 that supplies hydraulic oil (lubricating oil) to the lubricating portion of the PTO hydraulic clutch 590, and a lubricating portion of the input transmission shaft 511 that supports the hydraulic continuously variable transmission 500. The forward low-speed clutch hydraulic pressure switching valve 642 that supplies hydraulic oil (lubricating oil) to the lubricating portion of the forward low-speed hydraulic clutch 537, and the forward high-speed clutch hydraulic pressure that supplies hydraulic oil (lubricating oil) to the lubricating portion of the forward high-speed hydraulic clutch 539. The switching valve 643 is connected to a reverse clutch hydraulic pressure switching valve 644 that supplies hydraulic oil (lubricating oil) to the lubricating portion of the reverse hydraulic clutch 541. The hydraulic circuit 620 includes a relief valve, a flow rate adjustment valve, a check valve, an oil cooler, an oil filter, and the like.
上記の記載並びに図13及び図15~図20から明らかなように、走行機体2に搭載したエンジン5と、前記エンジン5の動力を変速するミッションケース17と、前記ミッションケース17の左右両側に後車軸ケース19を介して設けた後方走行部4とを備え、前記ミッションケース17内に、前記ミッションケース17経由の変速動力を前記左右の後方走行部4に伝達する差動機構506を配置している作業車両において、前記ミッションケース17に前室495、中間室497及び後室496を形成し、前記後室496内には前記後室496を前後に区画する支持壁部613,614を備え、前記差動機構506を前記後室496のうち前記支持壁部613,614よりも前方側に配置し、前記エンジン5の動力を変速して前記ミッションケース17から後向きに突出するPTO軸25に伝達するPTO変速機構505を、前記後室496のうち前記支持壁部613,614よりも後方側に配置しているから、前記ミッションケース17の前記後室496内に、前記差動機構506と前記PTO変速機構505(PTO伝動系統)とを選り分けして簡単且つコンパクトに配置でき、前記ミッションケース17の組み立て作業性並びにメンテナンス性の向上を図れる。
As is apparent from the above description and FIGS. 13 and 15 to 20, the engine 5 mounted on the traveling machine body 2, the transmission case 17 for shifting the power of the engine 5, and the left and right sides of the transmission case 17 And a rear traveling unit 4 provided via an axle case 19, and a differential mechanism 506 for transmitting transmission power via the mission case 17 to the left and right rear traveling units 4 is disposed in the mission case 17. In the working vehicle, a front chamber 495, an intermediate chamber 497, and a rear chamber 496 are formed in the mission case 17, and the rear chamber 496 includes support wall portions 613 and 614 that divide the rear chamber 496 in the front-rear direction. The differential mechanism 506 is disposed in front of the support wall portions 613 and 614 in the rear chamber 496, and the power of the engine 5 is changed to change the speed of the engine. Since the PTO transmission mechanism 505 for transmitting to the PTO shaft 25 projecting rearward from the case 17 is disposed behind the support wall portions 613 and 614 in the rear chamber 496, the rear of the transmission case 17 is In the chamber 496, the differential mechanism 506 and the PTO transmission mechanism 505 (PTO transmission system) can be selected and arranged in a simple and compact manner, and the assembly workability and maintenance performance of the mission case 17 can be improved.
また、前記ミッションケース17の後面開口部を着脱可能に塞ぐ後蓋部材492を備え、前記後蓋部材492を着脱することによって、前記後室496のうち前記支持壁部613,614よりも後方側に前記PTO変速機構505を出入可能に構成し、前記後室496のうち前記支持壁部613,614よりも後方側に前記PTO変速機構505を装着した状態では、前記支持壁部613,614と前記後蓋部材492とによって前記PTO変速機構505を支持しているから、前記ミッションケース17から前記後蓋部材492を取り外せば、前記PTO変速機構505を露出できることになる。従って、前記ミッションケース17の組み立て作業性及び分解作業性、前記PTO変速機構505のメンテナンス性の更なる向上を図れる。
In addition, a rear lid member 492 that detachably closes the rear opening of the transmission case 17 is provided, and the rear lid member 492 is detachably attached to the rear chamber 496 behind the support wall portions 613 and 614. In the state where the PTO transmission mechanism 505 is configured to be able to enter and exit, and the PTO transmission mechanism 505 is mounted on the rear side of the rear chamber 496 with respect to the support wall portions 613 and 614, the support wall portions 613 and 614 Since the PTO transmission mechanism 505 is supported by the rear cover member 492, the PTO transmission mechanism 505 can be exposed by removing the rear cover member 492 from the transmission case 17. Therefore, the assembly workability and disassembly workability of the transmission case 17 and the maintenance performance of the PTO transmission mechanism 505 can be further improved.
更に、背面視で矩形の頂点に位置するように、前記PTO変速機構505を構成する3本の軸591~593及びPTO軸25を前記支持壁部613,614と前記後蓋部材492とに軸支しているから、PTO出力の高出力化に伴う前記各軸25,591~593の反力を相殺し合うことが可能になる。その結果、前記各軸25,591~593に対する軸受構造の長寿命化を図れると共に、前記ミッションケース17及び前記走行機体2への振動伝達を軽減できる。
Further, the three shafts 591 to 593 and the PTO shaft 25 constituting the PTO speed change mechanism 505 are pivoted to the support wall portions 613 and 614 and the rear cover member 492 so as to be positioned at the vertex of the rectangle in the rear view. Therefore, the reaction forces of the shafts 25, 591 to 593 accompanying the increase in the PTO output can be offset. As a result, the life of the bearing structure for each of the shafts 25, 591 to 593 can be extended, and vibration transmission to the transmission case 17 and the traveling machine body 2 can be reduced.
次に、図13~図17及び図22~図24を参照しながら、左右のブレーキ機構563を作動させる一対のブレーキシリンダ630と、各ブレーキシリンダ630への作動油供給を制御するオートブレーキ電磁弁631(オートブレーキバルブ)との配置構造について説明する。図15~図17及び図22~図24に示すように、ミッションケース17上面のうち油圧式昇降機構22よりも前方、すなわち、後部変速ケース113の上面前部に、ブレーキシリンダ630の対とオートブレーキ電磁弁631の対を配置している。この場合、ブレーキシリンダ630の対とオートブレーキ電磁弁631の対とをブレーキ制御ケース664に組み付けてユニット化している。そして、ブレーキシリンダ630の対及びオートブレーキ電磁弁631の対を組み込んだブレーキ制御ケース664を後部変速ケース113の上面前部に着脱可能に締結している。
Next, with reference to FIGS. 13 to 17 and FIGS. 22 to 24, a pair of brake cylinders 630 for operating the left and right brake mechanisms 563 and an auto brake solenoid valve for controlling the supply of hydraulic oil to each brake cylinder 630 are described. The arrangement structure with 631 (auto brake valve) will be described. As shown in FIG. 15 to FIG. 17 and FIG. 22 to FIG. 24, the brake cylinder 630 pair and the auto A pair of brake solenoid valves 631 is arranged. In this case, a pair of brake cylinders 630 and a pair of autobrake solenoid valves 631 are assembled into a brake control case 664 to form a unit. A brake control case 664 incorporating a pair of brake cylinders 630 and a pair of autobrake solenoid valves 631 is detachably fastened to an upper front portion of the rear transmission case 113.
ミッションケース17の左外面、すなわち後部変速ケース113の左外面前部にはPTOバルブケース663を配置している。前述の通り、後部変速ケース113の上面前部にはブレーキ制御ケース664を配置している。従って、PTOバルブケース663とブレーキ制御ケース664とは、後部変速ケース113の外面側で近接して置かれている。ブレーキ制御ケース664への油圧配管とPTOバルブケース663(PTOクラッチ電磁弁627及び切換弁628)への油圧配管とは、互いに近接しているため共通化している。
A PTO valve case 663 is disposed on the left outer surface of the mission case 17, that is, on the front portion on the left outer surface of the rear transmission case 113. As described above, the brake control case 664 is disposed on the front upper surface of the rear transmission case 113. Therefore, the PTO valve case 663 and the brake control case 664 are placed close to each other on the outer surface side of the rear transmission case 113. Since the hydraulic piping to the brake control case 664 and the hydraulic piping to the PTO valve case 663 (PTO clutch electromagnetic valve 627 and switching valve 628) are close to each other, they are shared.
上記の記載並びに図13~図17及び図22~図24から明らかなように、走行機体2に搭載したエンジン5と、前記エンジン5の動力を変速する油圧無段変速機500を内蔵したミッションケース17と、前記ミッションケース17の左右両側に後車軸ケース19を介して設けた後方走行部4とを備え、前記ミッションケース17内に、前記左右の後方走行部4を制動させる左右のブレーキ機構563を配置し、前記ミッションケース17の上面に油圧式昇降機構22を搭載している作業車両において、前記各ブレーキ機構563を作動させる一対のブレーキシリンダ630と、前記各ブレーキシリンダ630への作動油供給を制御するオートブレーキバルブ631とを備え、前記ブレーキシリンダ630の対と前記オートブレーキバルブ631の対とをブレーキ制御ケース664に組み付けてユニット化し、前記ミッションケース17上面のうち前記油圧式昇降機構22よりも前方に前記ブレーキ制御ケース664を配置しているから、前記ミッションケース17上面のデッドスペースを有効利用して、前記ブレーキシリンダ630の対及び前記オートブレーキバルブ631の対を組み込んだ前記ブレーキ制御ケース664を配置でき、省スペース化を図れる。作業車両の制動に関連する油圧系統のコンパクト化を図れる。作業車両の製造ラインにおいて、制動関連の油圧系統の組み付け工数を低減できる。前記ブレーキシリンダ630の対及び前記オートブレーキバルブ631の対を前記ブレーキ制御ケース664ごと、前記ミッションケース17上面のうち前記油圧式昇降機構22よりも前方に取り付け・取り外しでき、前記ブレーキ制御ケース664のメンテナンス性を向上できる。
As is apparent from the above description and FIGS. 13 to 17 and FIGS. 22 to 24, a transmission case incorporating an engine 5 mounted on the traveling machine body 2 and a hydraulic continuously variable transmission 500 for shifting the power of the engine 5. 17 and a rear traveling unit 4 provided on both left and right sides of the transmission case 17 via a rear axle case 19, and a left and right brake mechanism 563 that brakes the left and right rear traveling units 4 in the transmission case 17. And a pair of brake cylinders 630 for operating the brake mechanisms 563 and supply of hydraulic oil to the brake cylinders 630 in a work vehicle in which the hydraulic lifting mechanism 22 is mounted on the upper surface of the transmission case 17. An auto brake valve 631 for controlling the brake cylinder 630 and the auto brake valve 631 is assembled to the brake control case 664 to form a unit, and the brake control case 664 is disposed in front of the hydraulic lifting mechanism 22 in the upper surface of the mission case 17. By effectively utilizing the dead space, the brake control case 664 incorporating the pair of brake cylinders 630 and the pair of auto brake valves 631 can be disposed, and space saving can be achieved. The hydraulic system related to the braking of the work vehicle can be made compact. In the work vehicle production line, it is possible to reduce the number of steps for assembling the brake related hydraulic system. The pair of brake cylinders 630 and the pair of auto brake valves 631 can be attached and detached together with the brake control case 664 in front of the hydraulic lifting mechanism 22 on the upper surface of the transmission case 17. Maintainability can be improved.
特に実施形態によると、前記ミッションケース17を、前部ケース112、中間ケース114及び後部ケース113の三者に分割して構成し、前記後部ケース113の上面前部に前記ブレーキ制御ケース664を取り付け、前記後部ケース112内には、前記エンジン5の動力を変速して前記ミッションケース17から後向きに突出するPTO軸25に伝達するPTO変速機構505と、前記PTO変速機構505への動力伝達を継断するPTO油圧クラッチ590とを配置し、前記後部ケース113の左右一側面に、前記PTO油圧クラッチ590を作動させるPTOバルブ627,628を取り付け、前記ブレーキ制御ケース664と前記PTOバルブ627,628とを近接させているから、前記ブレーキ制御ケース664への油圧配管及び前記PTOバルブ627,628への油圧配管を共通化できる。また、前記ブレーキ制御ケース664と前記PTOバルブ627,628とをつなぐ油圧配管の長さを短くできる。このため、油圧配管の取り回しを簡単化できて、作業車両全体としての油圧系統のコンパクト化を図れる。油圧ロスの抑制も図れる。
In particular, according to the embodiment, the transmission case 17 is divided into three parts of a front case 112, an intermediate case 114, and a rear case 113, and the brake control case 664 is attached to the upper front part of the rear case 113. In the rear case 112, the PTO transmission mechanism 505 for shifting the power of the engine 5 and transmitting it to the PTO shaft 25 protruding rearward from the transmission case 17 and the transmission of power to the PTO transmission mechanism 505 are connected. A PTO hydraulic clutch 590 to be disconnected, and PTO valves 627 and 628 for operating the PTO hydraulic clutch 590 are attached to the left and right side surfaces of the rear case 113, and the brake control case 664 and the PTO valves 627 and 628 are attached. Are close to each other, so that the hydraulic pressure to the brake control case 664 is It can be shared hydraulic piping to the pipe and the PTO valve 627 and 628. Also, the length of the hydraulic piping connecting the brake control case 664 and the PTO valves 627 and 628 can be shortened. For this reason, the handling of the hydraulic piping can be simplified, and the hydraulic system as a whole work vehicle can be made compact. Hydraulic loss can be suppressed.
次に、主として図22~図24を参照しながら、左右のブレーキ機構563を手動及び自動で作動させる構造の詳細について説明する。キャビン7内部の前面側には、ダッシュボード33を固定支持する縦長のボード支持板(図示省略)を立設していて、当該ボード支持板の上下中途部に左右横長のブレーキペダル軸720を支持させている。ブレーキペダル軸720には左右のブレーキペダル35の基端ボス部35aを被嵌している。実施形態では、左ブレーキペダル35の基端ボス部35aをブレーキペダル軸720と一体回動するように連結し、右ブレーキペダル35の基端ボス部をブレーキペダル軸720に回動可能に被嵌している。ブレーキ操作軸720の左端部には、前向きに突出する左用ペダル軸アーム721を固着している。右ブレーキペダル35の基端ボス部35aには、前向きに突出する右用ペダル軸アーム721を固着している。なお、ブレーキペダル軸720には、クラッチペダル37の基端ボス部37aも回動可能に被嵌している。
Next, the details of the structure for operating the left and right brake mechanisms 563 manually and automatically will be described with reference mainly to FIGS. A vertically long board support plate (not shown) for fixing and supporting the dashboard 33 is erected on the front side inside the cabin 7, and a horizontally long brake pedal shaft 720 is supported in the middle of the board support plate. I am letting. The brake pedal shaft 720 is fitted with base end boss portions 35 a of the left and right brake pedals 35. In the embodiment, the base end boss portion 35a of the left brake pedal 35 is connected so as to rotate integrally with the brake pedal shaft 720, and the base end boss portion of the right brake pedal 35 is rotatably fitted to the brake pedal shaft 720. is doing. A left pedal shaft arm 721 protruding forward is fixed to the left end portion of the brake operation shaft 720. A right pedal shaft arm 721 that protrudes forward is fixed to the base end boss portion 35 a of the right brake pedal 35. In addition, the base end boss portion 37a of the clutch pedal 37 is also rotatably fitted to the brake pedal shaft 720.
ボード支持板の左右下部側には、左右一対で横向きのブレーキ操作軸722を支持させている。左右のブレーキ操作軸722にはそれぞれ、左右のブレーキ操作ボス体723を回動可能に被嵌している。各ブレーキ操作ボス体723には三つのアーム724~726を突設している。三つのアーム724~726のうち左右中央に位置する中央アーム724は、上下長手のリンクロッド727を介して対応するペダル軸アーム721に連結している。リンクロッド727の下端側を中央アーム724に回動可能に枢着し、リンクロッド727の上端側をペダル軸アーム721に回動可能に枢着している。
A pair of left and right brake operation shafts 722 are supported on the left and right lower sides of the board support plate. Left and right brake operation boss bodies 723 are rotatably fitted to the left and right brake operation shafts 722, respectively. Three arms 724 to 726 protrude from each brake operation boss body 723. Of the three arms 724 to 726, the central arm 724 located at the center of the left and right is connected to the corresponding pedal shaft arm 721 via the vertically long link rod 727. The lower end side of the link rod 727 is pivotally attached to the central arm 724, and the upper end side of the link rod 727 is pivotally attached to the pedal shaft arm 721.
三つのアーム724~726のうち左右外側に位置する外側アーム725には、前後長手のブレーキロッド728の前端側を回動可能に枢着している。ここで、後部変速ケース113の左右外側面には、左右のブレーキ機構563を制動作動させる制動アーム729を前後回動可能に設けている。ブレーキロッド728の後端側は、制動アーム729の先端側に回動可能に枢着している。左右のブレーキペダル35を共に踏み込み操作することによって、左右のリンクロッド727を介して左右のブレーキロッド728が略同時に後方に押し出されて、左右の制動アーム729が後向きに回動する。その結果、左右のブレーキ機構563が略同時に作動して、左右両後車輪4にブレーキが掛かることになる。ペダル軸アーム721、ブレーキ操作ボス体723、リンクロッド727、ブレーキロッド728及び制動アーム729の組合せがブレーキリンク体730に相当する。
Among the three arms 724 to 726, the outer arm 725 positioned on the left and right outer sides is pivotally attached to the front end side of the longitudinally extending brake rod 728 so as to be rotatable. Here, braking arms 729 for braking the left and right brake mechanisms 563 are provided on the left and right outer surfaces of the rear transmission case 113 so as to be able to rotate back and forth. The rear end side of the brake rod 728 is pivotally attached to the front end side of the brake arm 729 so as to be rotatable. By depressing both the left and right brake pedals 35, the left and right brake rods 728 are pushed back substantially simultaneously via the left and right link rods 727, and the left and right brake arms 729 are rotated backward. As a result, the left and right brake mechanisms 563 are operated substantially simultaneously, and the left and right rear wheels 4 are braked. A combination of the pedal shaft arm 721, the brake operation boss body 723, the link rod 727, the brake rod 728, and the brake arm 729 corresponds to the brake link body 730.
三つのアーム724~726のうち左右内側に位置する内側アーム726には、索条部材としてのプッシュプルワイヤー731の前端側を回動可能に枢着している。ここで、後部変速ケース113の上面前部にのうちブレーキ制御ケース664の左方(ブレーキシリンダ630側)には、各ブレーキシリンダ630に対応して設けた左右の中継リンク732を配置している(図23参照)。プッシュプルワイヤー731の後端側は、対応する中継リンク732の左端側(一端側)に回動可能に枢着している。各中継リンク732の右端側(他端側)は、対応するブレーキシリンダ630に回動可能に枢着している。操縦ハンドル9の操舵角が所定角度以上になれば、旋回内側の後車輪4に対するオートブレーキ電磁弁631の切換作動によってブレーキシリンダ630が突出動し、対応する中継リンク732を介してプッシュプルワイヤー731を後方に引っ張る。そうすると、ブレーキ操作ボス体723を介してブレーキロッド728が略同時に後方に押し出されて、制動アーム729が後向きに回動する。その結果、旋回内側の後車輪4に対するブレーキ機構563が自動的に制動作動して、旋回内側の後車輪4にブレーキが掛かることになる(いわゆるオートブレーキ)。
Among the three arms 724 to 726, an inner arm 726 positioned on the left and right inner side is pivotally attached to a front end side of a push-pull wire 731 as a rope member so as to be rotatable. Here, left and right relay links 732 provided corresponding to the brake cylinders 630 are arranged on the left side (brake cylinder 630 side) of the brake control case 664 in the upper surface front portion of the rear transmission case 113. (See FIG. 23). The rear end side of the push-pull wire 731 is pivotably attached to the left end side (one end side) of the corresponding relay link 732. The right end side (other end side) of each relay link 732 is pivotally attached to the corresponding brake cylinder 630. When the steering angle of the steering handle 9 becomes equal to or greater than a predetermined angle, the brake cylinder 630 protrudes by the switching operation of the autobrake solenoid valve 631 with respect to the rear wheel 4 on the inside of the turn, and the push-pull wire 731 is moved via the corresponding relay link 732. Pull backwards. Then, the brake rod 728 is pushed rearward substantially simultaneously via the brake operation boss body 723, and the brake arm 729 rotates backward. As a result, the brake mechanism 563 for the rear wheel 4 inside the turn is automatically braked, and the rear wheel 4 inside the turn is braked (so-called autobrake).
図24に示すように、左右のブレーキリンク体730と左右のブレーキペダル35との間に、ブレーキシリンダ630によるブレーキ機構563の作動時(オートブレーキ作動時)にブレーキペダル35を追従作動させない第一融通部材733を設けている。また同様に、左右のブレーキリンク体730と左右のプッシュプルワイヤー731との間に、ブレーキペダル35によるブレーキ機構563の作動時にブレーキシリンダ630を追従作動させない第二融通部材736を設けている。
As shown in FIG. 24, the first brake pedal 35 is not operated to follow between the left and right brake link bodies 730 and the left and right brake pedals 35 when the brake mechanism 563 is operated by the brake cylinder 630 (when the automatic brake is operated). An accommodation member 733 is provided. Similarly, a second interchangeable member 736 is provided between the left and right brake link bodies 730 and the left and right push-pull wires 731 to prevent the brake cylinder 630 from following up when the brake mechanism 563 is operated by the brake pedal 35.
実施形態の第一融通部材733は、リンクロッド727の下端側とブレーキ操作ボス体723の中央アーム724とを回動可能に枢着する中央融通ピン734と、リンクロッド727の下端側に形成した縦長の第一長穴735とで構成している。リンクロッド727の第一長穴735に中央融通ピン734を遊嵌している。実施形態の第二融通部材736は、プッシュプルワイヤー731の前端側とブレーキ操作ボス体723の内側アーム726とを回動可能に枢着する内側融通ピン737と、プッシュプルワイヤー731の前端保持部に形成した前後長手の第二長穴738とで構成している。プッシュプルワイヤー731側の第二長穴738に内側融通ピン737を遊嵌している。
The first accommodation member 733 of the embodiment is formed on the lower end side of the link rod 727 and the central accommodation pin 734 that pivotably attaches to the lower end side of the link rod 727 and the central arm 724 of the brake operation boss body 723. A vertically long first long hole 735 is used. A central accommodation pin 734 is loosely fitted in the first elongated hole 735 of the link rod 727. The second interchangeable member 736 of the embodiment includes an inner interchangeable pin 737 that pivotably attaches the front end side of the push-pull wire 731 and the inner arm 726 of the brake operation boss body 723, and a front end holding portion of the push-pull wire 731. It is comprised with the 2nd long hole 738 of the front-back longitudinal direction formed in this. An inner accommodation pin 737 is loosely fitted in the second elongated hole 738 on the push-pull wire 731 side.
この場合、旋回内側の後車輪4に対応したブレーキシリンダ630によるブレーキ機構563の作動時(オートブレーキ作動時)には、ブレーキ操作ボス体723を介してブレーキロッド728が略同時に後方に押し出されるが、中央アーム724の中央融通ピン734は第一長穴735内を上向きに移動するだけであり、リンクロッド727ひいてはブレーキペダル35を動かすことはない。すなわち、オートブレーキ作動時に、旋回内側の後車輪4に対する片側のブレーキペダル35が不用意に追従作動することがない。
In this case, when the brake mechanism 563 is operated by the brake cylinder 630 corresponding to the rear wheel 4 inside the turn (when the automatic brake is operated), the brake rod 728 is pushed backward substantially simultaneously via the brake operation boss body 723. The central accommodation pin 734 of the central arm 724 only moves upward in the first elongated hole 735 and does not move the link rod 727 and hence the brake pedal 35. That is, when the automatic brake is operated, the brake pedal 35 on one side with respect to the rear wheel 4 on the inner side of the turn does not follow the operation carelessly.
また、左右両ブレーキペダル35によるブレーキ機構563の作動時には、左右のリンクロッド727を介して左右のブレーキロッド728が略同時に後方に押し出されるが、内側アーム726の内側融通ピン737は第二長穴738内を後方に移動するだけであり、左右のプッシュプルワイヤー731ひいては両ブレーキシリンダ630を追従作動させることはない。従って、左右のブレーキペダル35の踏み込み操作時にブレーキシリンダ630に不要な負荷がかかって、ブレーキシリンダ630が破損するおそれはない。
Further, when the brake mechanism 563 is operated by the left and right brake pedals 35, the left and right brake rods 728 are pushed rearward substantially simultaneously via the left and right link rods 727, but the inner interchange pin 737 of the inner arm 726 has a second elongated hole. 738 is only moved rearward, and the left and right push-pull wires 731 and therefore both brake cylinders 630 are not operated to follow. Therefore, there is no possibility that the brake cylinder 630 is damaged due to an unnecessary load applied to the brake cylinder 630 when the left and right brake pedals 35 are depressed.
なお、左右両制動アーム729はいずれも、索条部材の一例である駐車ブレーキワイヤー739を介して、操縦座席8と左サイドコラム42との間に配置した駐車ブレーキレバー43に連動連結している。駐車ブレーキレバー43を引き上げ操作すると、左右のワイヤー739を介して左右の制動アーム729が後方に回動して、左右のブレーキ機構563が略同時に作動し、左右両後車輪4にブレーキが掛かることになる。この場合、左右の制動アーム729が後方に回動して左右のブレーキロッド728が略同時に後方に引っ張られるが、中央アーム724の中央融通ピン734は第一長穴735内を上向きに移動するだけであり、リンクロッド727ひいてはブレーキペダル35を動かすことはない。そして、内側アーム726の内側融通ピン737は第二長穴738内を後方に移動するだけであり、左右のプッシュプルワイヤー731ひいては両ブレーキシリンダ630を追従作動させることはない。つまり、駐車ブレーキレバー43の操作時は、ブレーキペダル35及びブレーキシリンダ630の双方共、追従作動することはない。
Both left and right braking arms 729 are linked to a parking brake lever 43 disposed between the control seat 8 and the left side column 42 via a parking brake wire 739 which is an example of a rope member. . When the parking brake lever 43 is pulled up, the left and right braking arms 729 are rotated rearward via the left and right wires 739, the left and right brake mechanisms 563 are operated substantially simultaneously, and the left and right rear wheels 4 are braked. become. In this case, the left and right brake arms 729 are rotated rearward and the left and right brake rods 728 are pulled rearward substantially simultaneously, but the central interchange pin 734 of the central arm 724 only moves upward in the first elongated hole 735. The link rod 727 and therefore the brake pedal 35 are not moved. The inner interchange pin 737 of the inner arm 726 only moves backward in the second elongated hole 738, and does not cause the left and right push-pull wires 731 and therefore both brake cylinders 630 to follow. That is, when the parking brake lever 43 is operated, neither the brake pedal 35 nor the brake cylinder 630 is operated to follow.
上記の記載並びに図13、図14及び図22~図24から明らかなように、走行機体2に搭載したエンジン5と、前記エンジン5の動力を変速する油圧無段変速機500を内蔵したミッションケース17と、前記ミッションケース17の左右両側に後車軸ケース19を介して設けた後方走行部4とを備え、前記ミッションケース17内に、前記左右の後方走行部4を制動させる左右のブレーキ機構563を配置し、前記走行機体2の操縦座席8の前方に、前記左右のブレーキ機構563を制動操作する左右のブレーキペダル35を配置している作業車両において、前記各ブレーキ機構563を作動させる一対のブレーキシリンダ630と、前記各ブレーキシリンダ630への作動油供給を制御するオートブレーキバルブ631とを備え、左右のブレーキリンク体730を介して前記左右のブレーキペダル35と前記左右のブレーキ機構563とを連動連結すると共に、前記左右のブレーキリンク体730には、索条部材731を介して対応する前記ブレーキシリンダ630を連動連結しているから、前記ブレーキペダル35から前記ブレーキ機構563への機械的連結構造に対して、前記索条部材731経由で前記ブレーキシリンダ630を連結できる。このため、前記左右のブレーキ機構563を手動及び自動で作動させる構造を主として機械的な連結構造でとりまとめでき、簡素化してコンパクトに構成しつつ故障にも強いものにできる。
As is apparent from the above description and FIGS. 13, 14, and 22 to 24, a transmission case incorporating an engine 5 mounted on the traveling machine body 2 and a hydraulic continuously variable transmission 500 that shifts the power of the engine 5. 17 and a rear traveling unit 4 provided on both left and right sides of the transmission case 17 via a rear axle case 19, and a left and right brake mechanism 563 that brakes the left and right rear traveling units 4 in the transmission case 17. In a work vehicle in which left and right brake pedals 35 for braking the left and right brake mechanisms 563 are disposed in front of the control seat 8 of the traveling machine body 2, the pair of brake mechanisms 563 are operated. A brake cylinder 630, and an auto brake valve 631 for controlling the supply of hydraulic oil to each brake cylinder 630; The left and right brake pedals 35 and the left and right brake mechanisms 563 are linked to each other via a brake link body 730, and the brake cylinders 730 correspond to the left and right brake link bodies 730 via a rope member 731. Since the 630 is interlocked and connected, the brake cylinder 630 can be connected to the mechanical connection structure from the brake pedal 35 to the brake mechanism 563 via the cord member 731. For this reason, the structure for operating the left and right brake mechanisms 563 manually and automatically can be managed mainly by a mechanical connection structure, and can be simplified and made compact and resistant to failure.
また、前記左右のブレーキリンク体730と前記左右のブレーキペダル35との間に、前記ブレーキシリンダ630による前記ブレーキ機構563の作動時に前記ブレーキペダル35を追従作動させない第一融通部材733を設け、前記左右のブレーキリンク体730と前記左右の索条部材731との間に、前記ブレーキペダル35による前記ブレーキ機構563の作動時に前記ブレーキシリンダ630を追従作動させない第二融通部材736を設けているから、オートブレーキ作動時に片側のブレーキペダル35が不用意に追従作動することがない。一方、前記ブレーキペダル35の踏み込み操作時に前記ブレーキシリンダ630に不要な負荷がかかって、前記ブレーキシリンダ630が破損するおそれもない。従って、前記左右のブレーキ機構563を手動及び自動で作動させる構造を主として機械的な連結構造でとりまとめたものでありながら、手動作動の構造と自動作動の構造との両立を簡単且つ確実に実現できる。
Also, a first interchangeable member 733 is provided between the left and right brake link bodies 730 and the left and right brake pedals 35 so as not to follow the brake pedal 35 when the brake mechanism 563 is operated by the brake cylinder 630. Between the left and right brake link bodies 730 and the left and right cable members 731, a second interchangeable member 736 that does not follow the brake cylinder 630 when the brake mechanism 563 is operated by the brake pedal 35 is provided. The brake pedal 35 on one side does not follow up inadvertently when the automatic brake is activated. On the other hand, when the brake pedal 35 is depressed, an unnecessary load is applied to the brake cylinder 630 and the brake cylinder 630 is not damaged. Accordingly, the structure for manually and automatically operating the left and right brake mechanisms 563 is mainly organized by a mechanical connection structure, and the compatibility between the manual operation structure and the automatic operation structure can be realized easily and reliably. .
なお、本願発明における各部の構成は図示の実施形態に限定されるものではなく、本願発明の趣旨を逸脱しない範囲で種々変更が可能である。
The configuration of each part in the present invention is not limited to the illustrated embodiment, and various modifications can be made without departing from the spirit of the present invention.
2 走行機体
3 前車輪
4 後車輪
5 ディーゼルエンジン
8 操縦座席
17 ミッションケース
22 油圧式昇降機構
35 ブレーキペダル
112 前部変速ケース
113 後部変速ケース
114 中間ケース
563 ブレーキ機構
630 ブレーキシリンダ
631 オートブレーキ電磁弁
664 ブレーキ制御ケース
730 ブレーキリンク体
731 プッシュプルワイヤー
733 第一融通部材
736 第二融通部材 2 travelingmachine body 3 front wheel 4 rear wheel 5 diesel engine 8 control seat 17 mission case 22 hydraulic lifting mechanism 35 brake pedal 112 front transmission case 113 rear transmission case 114 intermediate case 563 brake mechanism 630 brake cylinder 631 auto brake solenoid valve 664 Brake control case 730 Brake link body 731 Push-pull wire 733 First accommodation member 736 Second accommodation member
3 前車輪
4 後車輪
5 ディーゼルエンジン
8 操縦座席
17 ミッションケース
22 油圧式昇降機構
35 ブレーキペダル
112 前部変速ケース
113 後部変速ケース
114 中間ケース
563 ブレーキ機構
630 ブレーキシリンダ
631 オートブレーキ電磁弁
664 ブレーキ制御ケース
730 ブレーキリンク体
731 プッシュプルワイヤー
733 第一融通部材
736 第二融通部材 2 traveling
Claims (2)
- 走行機体に搭載したエンジンと、前記エンジンの動力を変速する油圧無段変速機を内蔵したミッションケースと、前記ミッションケースの左右両側に後車軸ケースを介して設けた後方走行部とを備え、前記ミッションケース内に、前記左右の後方走行部を制動させる左右のブレーキ機構を配置し、前記走行機体の操縦座席の前方に、前記左右のブレーキ機構を制動操作する左右のブレーキペダルを配置している作業車両において、
前記各ブレーキ機構を作動させる一対のブレーキシリンダと、前記各ブレーキシリンダへの作動油供給を制御するオートブレーキバルブとを備え、
左右のブレーキリンク体を介して前記左右のブレーキペダルと前記左右のブレーキ機構とを連動連結すると共に、前記左右のブレーキリンク体には、索条部材を介して対応する前記ブレーキシリンダを連動連結し、
前記左右のブレーキリンク体と前記左右のブレーキペダルとの間に、前記ブレーキシリンダによる前記ブレーキ機構の作動時に前記ブレーキペダルを追従作動させない第一融通部材を設け、前記左右のブレーキリンク体と前記左右の索条部材との間に、前記ブレーキペダルによる前記ブレーキ機構の作動時に前記ブレーキシリンダを追従作動させない第二融通部材を設けている、
作業車両。 An engine mounted on the traveling machine body, a transmission case incorporating a hydraulic continuously variable transmission for shifting the power of the engine, and a rear traveling unit provided on both left and right sides of the transmission case via a rear axle case, In the transmission case, left and right brake mechanisms for braking the left and right rear traveling units are disposed, and left and right brake pedals for braking the left and right brake mechanisms are disposed in front of the control seat of the traveling aircraft body. In work vehicles,
A pair of brake cylinders for operating each of the brake mechanisms; and an auto brake valve for controlling supply of hydraulic oil to each of the brake cylinders;
The left and right brake pedals and the left and right brake mechanisms are interlocked and connected via left and right brake link bodies, and the corresponding brake cylinders are interlocked and connected to the left and right brake link bodies via rope members. ,
A first interchangeable member is provided between the left and right brake link bodies and the left and right brake pedals to prevent the brake pedal from following up when the brake mechanism is operated by the brake cylinder. A second interchangeable member that does not follow the brake cylinder when the brake mechanism is actuated by the brake pedal,
Work vehicle. - 前記ブレーキシリンダの対と前記オートブレーキバルブの対とをブレーキ制御ケースに組み付けてユニット化し、前記ミッションケース上面のうち油圧式昇降機構よりも前方に前記ブレーキ制御ケースを配置している、
請求項1に記載の作業車両。 The brake cylinder pair and the auto brake valve pair are assembled as a unit into a brake control case, and the brake control case is disposed in front of the hydraulic lifting mechanism on the upper surface of the mission case.
The work vehicle according to claim 1.
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- 2014-10-15 JP JP2014211128A patent/JP6435155B2/en not_active Expired - Fee Related
-
2015
- 2015-09-29 WO PCT/JP2015/077538 patent/WO2016059968A1/en active Application Filing
Patent Citations (7)
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JPH0616059A (en) * | 1992-07-01 | 1994-01-25 | Kubota Corp | Four wheel drive type working vehicle |
JPH11262301A (en) * | 1998-03-18 | 1999-09-28 | Yanmar Diesel Engine Co Ltd | Steering-controlling device for working vehicle |
US20020060103A1 (en) * | 2000-06-16 | 2002-05-23 | Steffen Ritz | Vehicle |
JP2005262918A (en) * | 2004-03-16 | 2005-09-29 | Iseki & Co Ltd | Brake cylinder attachment structure for tractor |
JP2006089034A (en) * | 2005-10-11 | 2006-04-06 | Iseki & Co Ltd | Tractor steering device |
JP2008155668A (en) * | 2006-12-20 | 2008-07-10 | Mitsubishi Agricult Mach Co Ltd | Working vehicle |
JP2009045991A (en) * | 2007-08-17 | 2009-03-05 | Yanmar Co Ltd | Working vehicle |
Also Published As
Publication number | Publication date |
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JP6435155B2 (en) | 2018-12-05 |
JP2016078593A (en) | 2016-05-16 |
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