WO2014091683A1 - 建設機械の油圧回路 - Google Patents
建設機械の油圧回路 Download PDFInfo
- Publication number
- WO2014091683A1 WO2014091683A1 PCT/JP2013/006796 JP2013006796W WO2014091683A1 WO 2014091683 A1 WO2014091683 A1 WO 2014091683A1 JP 2013006796 W JP2013006796 W JP 2013006796W WO 2014091683 A1 WO2014091683 A1 WO 2014091683A1
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- hydraulic
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- return
- control valve
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2217—Hydraulic or pneumatic drives with energy recovery arrangements, e.g. using accumulators, flywheels
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2221—Control of flow rate; Load sensing arrangements
- E02F9/2225—Control of flow rate; Load sensing arrangements using pressure-compensating valves
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2221—Control of flow rate; Load sensing arrangements
- E02F9/2239—Control of flow rate; Load sensing arrangements using two or more pumps with cross-assistance
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2278—Hydraulic circuits
- E02F9/2282—Systems using center bypass type changeover valves
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2278—Hydraulic circuits
- E02F9/2292—Systems with two or more pumps
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/205—Systems with pumps
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/205—Systems with pumps
- F15B2211/20576—Systems with pumps with multiple pumps
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/21—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge
- F15B2211/212—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge the pressure sources being accumulators
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/255—Flow control functions
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/305—Directional control characterised by the type of valves
- F15B2211/30525—Directional control valves, e.g. 4/3-directional control valve
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
- F15B2211/31552—Directional control characterised by the connections of the valve or valves in the circuit being connected to an output member and a return line
- F15B2211/31558—Directional control characterised by the connections of the valve or valves in the circuit being connected to an output member and a return line having a single output member
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/40—Flow control
- F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
- F15B2211/4159—Flow control characterised by the connections of the flow control means in the circuit being connected to a pressure source, an output member and a return line
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/40—Flow control
- F15B2211/45—Control of bleed-off flow, e.g. control of bypass flow to the return line
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/40—Flow control
- F15B2211/46—Control of flow in the return line, i.e. meter-out control
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/50—Pressure control
- F15B2211/515—Pressure control characterised by the connections of the pressure control means in the circuit
- F15B2211/5156—Pressure control characterised by the connections of the pressure control means in the circuit being connected to a return line and a directional control valve
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/50—Pressure control
- F15B2211/555—Pressure control for assuring a minimum pressure, e.g. by using a back pressure valve
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/61—Secondary circuits
- F15B2211/611—Diverting circuits, e.g. for cooling or filtering
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/62—Cooling or heating means
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
- F15B2211/7051—Linear output members
- F15B2211/7053—Double-acting output members
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/80—Other types of control related to particular problems or conditions
- F15B2211/86—Control during or prevention of abnormal conditions
- F15B2211/8609—Control during or prevention of abnormal conditions the abnormal condition being cavitation
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/80—Other types of control related to particular problems or conditions
- F15B2211/88—Control measures for saving energy
Definitions
- the present invention relates to a hydraulic circuit of a construction machine such as a hydraulic excavator.
- the excavator is a crawler-type lower traveling body, an upper revolving body 2 mounted on the upper revolving body 2 so as to be rotatable about an axis X perpendicular to the ground, and attached to the upper revolving body 2 for excavation work.
- a front attachment 3 that operates so as to perform the above, a plurality of hydraulic actuators, and a hydraulic pump that supplies hydraulic oil to these hydraulic actuators.
- the front attachment 3 includes a boom 4 that can freely move up and down, an arm 5 that is pivotally connected to the tip of the boom 4 around a horizontal axis in the left-right direction, and a tip that rotates around the horizontal axis in the left-right direction.
- a bucket 6 that is movably coupled.
- the hydraulic actuator includes a boom cylinder 7 that raises and lowers the boom 4, an arm cylinder 8 that rotates the arm 5 in the pushing and pulling directions, and a bucket 6 that rotates the bucket 6 so that the bucket 6 performs excavation and dumping operations.
- a bucket cylinder 9 to be moved, left and right traveling motors that drive the lower traveling body 1, and a swing motor that drives the upper swing body 2 to rotate are included.
- a control valve is interposed between each hydraulic actuator and a hydraulic pump as its hydraulic source, and this control valve operates to control the supply and discharge of pressure oil to and from each hydraulic actuator from the hydraulic pump.
- the actuator circuits that are hydraulic circuits for operating the respective hydraulic actuators
- the hydraulic cylinder circuit for operating the hydraulic cylinder there is a problem that the pressure loss on the return side becomes large when the hydraulic cylinder is contracted. is there.
- a circuit for moving the arm cylinder 8 will be described with reference to FIG.
- This circuit includes a hydraulic pump 10, a tank T, a hydraulic pilot control valve 11, a remote control valve (not shown), a head side pipe 12, a rod side pipe 13, and a return pipe 14. .
- the control valve 11 is interposed between the hydraulic pump 10 and the tank T and the arm cylinder 8 and is operated by the remote control valve.
- the arm cylinder 8 includes a cylinder body, a piston loaded in the cylinder body, and a rod extending in the axial direction from the piston, and the piston has a head side chamber (also referred to as a bottom side chamber) 8a in the cylinder body. And the rod side chamber 8b.
- the head side pipe line 12 connects the head side chamber 8 a and the control valve 11, and the rod side pipe line 13 connects the rod side chamber 8 b and the control valve 11.
- the return line 14 connects the control valve 11 and the tank T, and the return line 14 includes a check valve with a spring, which is a back pressure valve 15 for establishing a constant back pressure, and an oil cooler 16. Is provided.
- the control valve 11 has a neutral position 11a, an arm pushing (cylinder contraction) position 11b, and an arm pulling (cylinder extension) position 11c. By switching between these positions, the supply of pressure oil to the arm cylinder 8 is performed. It is possible to control the exhaust, that is, the expansion / contraction operation of the arm cylinder 8.
- the pressure loss on the return side occurs when the volume of the head side chamber 8a is larger than that of the rod side chamber 8b. That is, when the arm cylinder 8 operates in the contracting direction, a large amount of oil flows from the head side chamber 8a to the return pipe 14 due to the difference in volume between the chambers 8a and 8b. The pressure loss in the pressure valve 15 and the oil cooler 16 increases, and the power loss increases. In particular, when the arm 5 is driven in the push direction, the weight of the arm 5 accelerates the movement of the arm 5, so that the pressure loss becomes particularly large.
- Patent Document 1 discloses a hydraulic circuit including two return pipes as a flow path for returning the return oil from the head side to the tank when the hydraulic cylinder is contracted.
- a quick return circuit with a relief valve is connected to one return pipe, and a part of the return oil on the head side passes through the quick return circuit when the hydraulic cylinder is fully operated in the contraction direction. To return directly to the tank. Thereby, the pressure loss on the return side can be reduced.
- the present invention provides a hydraulic circuit of a construction machine including a hydraulic cylinder, which can obtain a high pressure loss reduction effect with respect to pressure loss due to return oil from the head side chamber of the hydraulic cylinder with a simple circuit configuration. With the goal.
- the hydraulic circuit provided by the present invention has a hydraulic pump that discharges hydraulic oil, a head side chamber, and a rod side chamber, and is supplied with hydraulic oil from the hydraulic pump to the head side chamber and the rod side chamber.
- a hydraulic cylinder that operates, a control valve that is provided between the hydraulic pump and the hydraulic cylinder and operates to control supply and discharge of the hydraulic oil to and from the hydraulic cylinder, a head side chamber of the hydraulic cylinder, and the control A head side pipe connecting the valve, a rod side pipe connecting the rod side chamber of the hydraulic cylinder and the control valve, a return pipe connecting the control valve and the tank, and a back pressure valve provided in the return pipe
- An oil cooler provided in the return pipe, and a pipe different from the return pipe, the control valve and the tank A tank direct line, and the control valve includes a first return passage for guiding return oil from the head side chamber of the hydraulic cylinder to the tank direct line, and return oil from the rod side chamber of the hydraulic cylinder. And a second return flow path for guiding the flow to the return pipe.
- FIG. 1 shows a hydraulic circuit according to this embodiment, and this hydraulic circuit is mounted on the hydraulic excavator shown in FIG.
- the hydraulic circuit includes first and second hydraulic pumps 17 and 18 that discharge hydraulic fluid when driven by an engine, a plurality of hydraulic actuators, a plurality of control valves, a head side conduit 35, and a rod side.
- a pipe line 34, a return pipe line, a back pressure valve 31, an oil cooler 32, a tank direct line 33, and a tank T are provided.
- the plurality of hydraulic actuators include a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a right travel motor 19, a left travel motor 20, and a turning motor 21.
- the hydraulic oil discharged from the first hydraulic pump 17 can be supplied to the boom cylinder 7, the bucket cylinder 9 and the right travel motor 19, and the hydraulic oil discharged from the second hydraulic pump 18 is The arm cylinder 8, the left traveling motor 20, and the turning motor 21 can be supplied.
- the plurality of control valves include a boom control valve 22 interposed between the first hydraulic pump 17 and the boom cylinder 7, and an arm interposed between the second hydraulic pump 18 and the arm cylinder 8.
- Right-hand drive that intervenes between the control valve 23 for use, the control valve 24 for bucket that is interposed between the first hydraulic pump 17 and the bucket cylinder 9, and the right-hand drive motor 19.
- Control valve 25 left travel control valve 26 interposed between the second hydraulic pump 18 and the left travel motor 20, and swivel interposed between the second hydraulic pump 18 and the swing motor 21.
- Control valve 27 Each of these control valves 22 to 27 is of a hydraulic pilot type, and is operated using a remote control valve (not shown) to control the supply and discharge of hydraulic fluid to the corresponding hydraulic actuator, that is, to operate the hydraulic actuator. Operate to control.
- the arm cylinder 8 corresponds to a hydraulic cylinder that is a subject of the present invention.
- the arm cylinder 8 has a head side chamber 8a and a rod side chamber 8b.
- the head side pipe line 35 connects the head side oil chamber 8 a and the arm control valve 23, and the rod side pipe line 34 connects the rod side oil chamber 8 b and the arm control valve 23.
- the return pipe line includes a plurality of individual return pipe lines 28 provided for the control valves 22 to 27, a main tank line 30 connected to the tank T, and return oil flowing through the individual return pipe lines 28.
- First and second tank lines 29A and 29B joined to the main tank line 30, and the return oil from each of the hydraulic actuators 7 to 9 and 19 to 21 is basically routed through this return pipe Returned to tank T.
- the first tank line 29A is provided for a hydraulic actuator driven by the first hydraulic pump 17, and the second tank line 29B is provided for a hydraulic actuator driven by the second hydraulic pump 18.
- the second tank lines 29A and 29B are both connected to the tank T via the main tank line 30.
- the back pressure valve 31 and the oil cooler 32 are provided in the main tank line 30 in series with each other.
- the back pressure valve 31 is a valve for raising a constant back pressure
- the oil cooler 32 is for cooling the hydraulic oil.
- the tank direct line 33 is provided for the arm cylinder 8 and directly connects the arm control valve 23 and the tank T separately from the original return line.
- the arm control valve 23 is configured so that return oil from the rod side chamber 8b through the rod side pipe 34 is routed through the same route as before, that is, through the individual return pipe 28, the second tank line 29B, and the main tank line 30. While returning to the tank T, the return oil from the head side chamber 8 a through the head side pipe 35 is directly returned to the tank T through a route passing through the tank direct line 33.
- the arm control valve 23 has a neutral position 23a, an arm pushing position 23b, and an arm pulling position 23c.
- the hydraulic oil from the second hydraulic pump is supplied to the rod side pipe.
- a supply flow path that leads to the path 34 to reach the rod side chamber 8b of the arm cylinder 8 is formed, and at the arm pulling position 23b, the hydraulic oil is guided to the head side pipe line 35 to reach the head side chamber 8a of the arm cylinder 8.
- a supply channel is formed.
- the control valve 23 has first and second tank ports 36 and 37 as tank ports for guiding the return oil to the tank T.
- a return line 28 is connected, and the tank direct line 33 is connected to the second tank port 37.
- the control valve 23 is a return oil that is returned from the rod side chamber 8b through the rod side conduit 34 through the rod side conduit 8 at the arm pulling position 23c.
- a first return flow channel 231 that leads to a return pipeline including the individual return pipeline 28, and a flow channel that communicates the head side pipeline 35 to the second tank port 37 at the arm pushing position 23c, that is,
- a second return flow path 232 for guiding return oil returned from the head side chamber 8a through the head side pipe line 35 to the tank direct line 33.
- the hydraulic circuit according to this embodiment further connects the regeneration conduit 38 that connects the tank direct line 33 and the rod side conduit 34, and the tank direct line 33 and the second tank line 29B. And a supply line 39.
- a regeneration check valve 40 is provided in the regeneration conduit 38, and this regeneration check valve 40 allows only the flow of oil from the tank direct line 33 toward the rod side conduit 34.
- the replenishment conduit 39 is provided with a replenishment check valve 41, and this replenishment check valve 41 allows only the flow of oil from the tank direct line 33 toward the second tank line 29B.
- replenishment pipelines 42 and 43 with check valves are also provided between the second tank line 29B and both the rod side and head side pipelines 34 and 35, respectively.
- the hydraulic oil in the head side chamber 8a of the arm cylinder 8 always moves to the tank T through the tank direct line 33 without the back pressure valve 31 and the oil cooler 32 when operating in the arm pushing (arm cylinder contraction) direction. Since it returns directly, the effect of reducing the pressure loss caused by the return oil can be enhanced. In addition, since this effect can be obtained by adding only one low-pressure pipe called the tank direct line 33, compared with the known technique described in Patent Document 1, the circuit configuration is simpler and requires fewer parts and has a lower cost. The above effect can be obtained.
- the regeneration pipe line 38 with the check valve 40 connects the tank direct line 33 and the rod side pipe line 34, so that the arm cylinder 8 is operated alone, that is, a composite Even when the return oil from the other actuator circuit cannot be used for regeneration to the cylinder rod 8b side as in the operation, the return oil from the head side chamber 8a of the arm cylinder 8 is turned to the rod side pipe 34. It is possible to prevent the occurrence of cavitation.
- the supply line 39 with the check valve 41 connects the tank direct line 33 and the tank line 29 so that the arm cylinder 8 and other hydraulic actuators are operated simultaneously. Sometimes it is possible to replenish return oil from the head side chamber 8a of the arm cylinder 8 to other hydraulic actuators.
- the present invention is not limited to the embodiment described above.
- the circuit of the hydraulic cylinder targeted by the present invention that is, the circuit provided with the tank direct line is not limited to the circuit related to the arm cylinder 8 as shown in the embodiment.
- the present invention can be applied to a circuit related to another hydraulic cylinder (for example, a bucket cylinder or a boom cylinder) instead of the circuit related to the arm cylinder 8 or together with the circuit related to the arm cylinder 8.
- construction machine provided with the hydraulic circuit according to the present invention is not limited to the hydraulic excavator, and can be applied to other construction machines configured with the hydraulic excavator as a base, for example.
- a hydraulic circuit of a construction machine including a hydraulic cylinder has a simple circuit configuration, and a high pressure loss reduction effect is obtained with respect to pressure loss due to return oil from the head side chamber of the hydraulic cylinder.
- This hydraulic circuit has a hydraulic pump that discharges hydraulic oil, a head side chamber and a rod side chamber, and a hydraulic cylinder that expands and contracts by receiving the supply of hydraulic oil from the hydraulic pump to the head side chamber and the rod side chamber.
- a control valve that is provided between the hydraulic pump and the hydraulic cylinder and operates to control supply and discharge of the hydraulic oil to and from the hydraulic cylinder, and a head side chamber of the hydraulic cylinder and the control valve are connected to each other A head side pipe, a rod side pipe connecting the rod side chamber of the hydraulic cylinder and the control valve, a return pipe connecting the control valve and the tank, a back pressure valve provided in the return pipe, and the return
- the oil cooler provided in the pipe and the return pipe are separate pipes that directly connect the control valve and the tank.
- a control valve wherein the control valve includes a first return passage for guiding return oil from the head side chamber of the hydraulic cylinder to the tank direct line, and return oil from the rod side chamber of the hydraulic cylinder to the return pipe. And a second return channel for guiding.
- the hydraulic oil in the head side chamber of the hydraulic cylinder always returns directly to the tank through the tank direct line without the back pressure valve and oil cooler, so that when the hydraulic cylinder is operated in the contracting direction,
- the effect of reducing the pressure loss due to the return oil can be enhanced.
- the above effect can be obtained with a simple circuit configuration with a small number of parts only by adding one low-pressure pipe called a tank direct line, and the cost can be reduced.
- the hydraulic circuit according to the present invention further includes a regeneration conduit that connects the tank direct line and the rod side conduit, and the regeneration conduit is only for the flow of oil from the tank direct line to the rod side conduit. It is desirable to include a regenerative check valve that allows This regenerative pipe line is connected to the hydraulic cylinder head side chamber even when the hydraulic cylinder alone is operated, that is, when the return oil from another actuator circuit cannot be used for regeneration to the cylinder rod side, such as during combined operation. It is possible to prevent the occurrence of cavitation by turning the return oil to the rod side pipe line.
- the hydraulic circuit according to the present invention includes a hydraulic actuator other than the hydraulic cylinder, another control valve provided for the other hydraulic actuator, and a supply pipe, and the return pipe includes the hydraulic pressure
- the return pipe includes the hydraulic pressure
- the replenishment conduit includes a replenishment check valve that connects the tank direct line and the tank line and permits only a flow of oil from the tank direct line to the tank line. Is desirable.
- This replenishment pipeline replenishes the other hydraulic actuators with the return oil in the head side chamber of the hydraulic cylinder at the time of combined operation in which the hydraulic cylinder connected to the tank direct line and other hydraulic actuators are operated simultaneously. Enable.
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Abstract
Description
Claims (3)
- 建設機械に設けられる油圧回路であって、
作動油を吐出する油圧ポンプと、
へッド側室及びロッド側室を有し、これらヘッド側室及びロッド側室への前記油圧ポンプからの作動油の供給を受けて伸縮作動する油圧シリンダと、
前記油圧ポンプと前記油圧シリンダとの間に設けられて当該油圧シリンダに対する前記作動油の給排を制御するように作動するコントロールバルブと、
前記油圧シリンダのヘッド側室と前記コントロールバルブとを結ぶヘッド側管路と、
前記油圧シリンダのロッド側室と前記コントロールバルブとを結ぶロッド側管路と、
前記コントロールバルブとタンクとを結ぶ戻り管路と、
前記戻り管路に設けられる背圧弁と、
前記戻り管路に設けられるオイルクーラと、
前記戻り管路とは別の管路であって、前記コントロールバルブとタンクとを直結するタンク直通ラインと、を備え、前記コントロールバルブは、前記油圧シリンダのヘッド側室からの戻り油を前記タンク直通ラインに導く第1戻り流路と、前記油圧シリンダのロッド側室からの戻り油を前記戻り管路に導く第2戻り流路と、を有する、建設機械の油圧回路。 - 請求項1記載の建設機械の油圧回路であって、前記タンク直通ラインと前記ロッド側管路とを接続する再生管路をさらに備え、この再生管路が、前記タンク直通ラインからロッド側管路に向かう油の流れのみを許容する再生チェック弁を含む、建設機械の油圧回路。
- 請求項1または2記載の建設機械の油圧回路であって、前記油圧シリンダ以外の他の油圧アクチュエータと、当該他の油圧アクチュエータについて設けられる他のコントロールバルブと、補給管路と、を備え、前記戻り管路は、前記油圧シリンダについて設けられた前記コントロールバルブ及び前記他のコントロールバルブについてそれぞれ設けられる複数の個別戻り管路と、これらの個別戻り管路に共通するタンクラインであって当該各個別戻り管路をタンクに接続するタンクラインと、を含み、前記補給管路は、前記タンク直通ラインと前記タンクラインとを接続するとともに、前記タンク直通ラインからタンクラインに向かう油の流れのみを許容する補給チェック弁を含む、建設機械の油圧回路。
Priority Applications (4)
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US14/443,444 US9863448B2 (en) | 2012-12-13 | 2013-11-19 | Hydraulic circuit for construction machine |
CN201380061558.4A CN104822950B (zh) | 2012-12-13 | 2013-11-19 | 工程机械的液压回路 |
KR1020157018117A KR102101054B1 (ko) | 2012-12-13 | 2013-11-19 | 건설 기계의 유압 회로 |
EP13861805.3A EP2933501B1 (en) | 2012-12-13 | 2013-11-19 | Hydraulic circuit for construction machine |
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JP2012-272216 | 2012-12-13 | ||
JP2012272216A JP6089666B2 (ja) | 2012-12-13 | 2012-12-13 | 建設機械の油圧回路 |
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WO2014091683A1 true WO2014091683A1 (ja) | 2014-06-19 |
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US (1) | US9863448B2 (ja) |
EP (1) | EP2933501B1 (ja) |
JP (1) | JP6089666B2 (ja) |
KR (1) | KR102101054B1 (ja) |
CN (1) | CN104822950B (ja) |
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JP6999320B2 (ja) * | 2017-07-26 | 2022-01-18 | 住友建機株式会社 | ショベル |
CN108978770B (zh) * | 2018-06-27 | 2021-05-14 | 柳州柳工挖掘机有限公司 | 挖掘机液压供油控制***及挖掘机 |
Citations (5)
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JPH04325222A (ja) * | 1991-04-24 | 1992-11-13 | Nissei Plastics Ind Co | 射出成形機の油圧装置 |
JPH09151488A (ja) * | 1995-11-22 | 1997-06-10 | Komatsu Ltd | 油圧ショベルの油圧回路 |
JP2002339904A (ja) | 2001-05-21 | 2002-11-27 | Komatsu Ltd | 建設機械の油圧回路 |
JP2005155698A (ja) * | 2003-11-21 | 2005-06-16 | Sumitomo (Shi) Construction Machinery Manufacturing Co Ltd | 油圧作業機械の油圧回路 |
JP2006071105A (ja) * | 2005-09-28 | 2006-03-16 | Komatsu Ltd | 建設機械の油圧回路 |
Family Cites Families (6)
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JP3727006B2 (ja) * | 1999-10-19 | 2005-12-14 | 日立建機株式会社 | 多段伸縮アームの油圧回路 |
JP2002097673A (ja) * | 2000-09-22 | 2002-04-02 | Shin Caterpillar Mitsubishi Ltd | 作業機械の油圧回路 |
JP3795785B2 (ja) * | 2001-09-27 | 2006-07-12 | 日立建機株式会社 | 多段伸縮アームの油圧回路 |
JP4151597B2 (ja) | 2004-03-31 | 2008-09-17 | コベルコ建機株式会社 | 油圧制御回路および建設機械 |
JP2010174574A (ja) | 2009-01-30 | 2010-08-12 | Caterpillar Japan Ltd | 作業機械 |
JP2010185515A (ja) * | 2009-02-12 | 2010-08-26 | Komatsu Ltd | 油圧駆動装置 |
-
2012
- 2012-12-13 JP JP2012272216A patent/JP6089666B2/ja active Active
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2013
- 2013-11-19 WO PCT/JP2013/006796 patent/WO2014091683A1/ja active Application Filing
- 2013-11-19 EP EP13861805.3A patent/EP2933501B1/en active Active
- 2013-11-19 KR KR1020157018117A patent/KR102101054B1/ko active IP Right Grant
- 2013-11-19 US US14/443,444 patent/US9863448B2/en active Active
- 2013-11-19 CN CN201380061558.4A patent/CN104822950B/zh active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04325222A (ja) * | 1991-04-24 | 1992-11-13 | Nissei Plastics Ind Co | 射出成形機の油圧装置 |
JPH09151488A (ja) * | 1995-11-22 | 1997-06-10 | Komatsu Ltd | 油圧ショベルの油圧回路 |
JP2002339904A (ja) | 2001-05-21 | 2002-11-27 | Komatsu Ltd | 建設機械の油圧回路 |
JP2005155698A (ja) * | 2003-11-21 | 2005-06-16 | Sumitomo (Shi) Construction Machinery Manufacturing Co Ltd | 油圧作業機械の油圧回路 |
JP2006071105A (ja) * | 2005-09-28 | 2006-03-16 | Komatsu Ltd | 建設機械の油圧回路 |
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JP6089666B2 (ja) | 2017-03-08 |
CN104822950A (zh) | 2015-08-05 |
EP2933501B1 (en) | 2018-01-10 |
KR20150093217A (ko) | 2015-08-17 |
JP2014118984A (ja) | 2014-06-30 |
US20150330413A1 (en) | 2015-11-19 |
EP2933501A4 (en) | 2016-03-30 |
KR102101054B1 (ko) | 2020-04-14 |
EP2933501A1 (en) | 2015-10-21 |
US9863448B2 (en) | 2018-01-09 |
CN104822950B (zh) | 2017-03-08 |
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