EP0987414A2 - V-type internal combustion engine for vehicle - Google Patents
V-type internal combustion engine for vehicle Download PDFInfo
- Publication number
- EP0987414A2 EP0987414A2 EP99116978A EP99116978A EP0987414A2 EP 0987414 A2 EP0987414 A2 EP 0987414A2 EP 99116978 A EP99116978 A EP 99116978A EP 99116978 A EP99116978 A EP 99116978A EP 0987414 A2 EP0987414 A2 EP 0987414A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- crank shaft
- crank
- transmission unit
- shaft
- timing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B61/00—Adaptations of engines for driving vehicles or for driving propellers; Combinations of engines with gearing
- F02B61/02—Adaptations of engines for driving vehicles or for driving propellers; Combinations of engines with gearing for driving cycles
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/16—Engines characterised by number of cylinders, e.g. single-cylinder engines
- F02B75/18—Multi-cylinder engines
- F02B75/22—Multi-cylinder engines with cylinders in V, fan, or star arrangement
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/02—Engines characterised by their cycles, e.g. six-stroke
- F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
- F02B2075/027—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle four
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/16—Engines characterised by number of cylinders, e.g. single-cylinder engines
- F02B75/18—Multi-cylinder engines
- F02B2075/1804—Number of cylinders
- F02B2075/1808—Number of cylinders two
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B2275/00—Other engines, components or details, not provided for in other groups of this subclass
- F02B2275/20—SOHC [Single overhead camshaft]
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F1/00—Cylinders; Cylinder heads
- F02F1/24—Cylinder heads
- F02F2001/244—Arrangement of valve stems in cylinder heads
- F02F2001/245—Arrangement of valve stems in cylinder heads the valve stems being orientated at an angle with the cylinder axis
Definitions
- the present invention relates to a V-type internal combustion engine for a vehicle which is mounted to such as a motorcycle, and particularly to an improved V-type internal combustion engine for a vehicle, in which first and second journals disposed on a crank shaft with a crank portion held therebetween are supported by a crank case via bearings respectively; a front bank and a rear bank disposed in such a manner as to cross each other in a V-shape centered at said crank shaft are sequentially mounted in the crank case; a primary transmission unit for transmitting a power from said crank shaft to a clutch, a starting transmission unit for transmitting a drive force of a starting motor to said crank shaft, first and second timing transmission units for driving valve system cam shafts of said first and second banks respectively, and a generator are connected to said crank shaft; and said crank shaft is disposed laterally in a state that the crank shaft is mounted on said vehicle.
- the V-type internal combustion engine for a vehicle of this type has been known, for example, from Japanese patent Laid-open No. Sho 64-83912, in which a first timing transmission unit, a starting transmission unit and a generator are connected to one end portion, projecting outwardly from a first journal, of a crank shaft, and a second timing transmission unit and primary transmission unit are connected to the other end portion, projecting outwardly from a second journal, of the crank shaft.
- the above-described prior art configuration has a problem that since the first and second timing transmission units are connected to both the end portions of the crank shaft, the assembling characteristic of the first and second timing units becomes degraded. Another problem is that since the starting transmission unit and the generator are disposed outside one timing transmission unit while the primary transmission unit is disposed outside the other timing transmission unit, the generator and the units disposed outside the timing transmission units must be removed for carrying out the maintenance of the timing transmission units. Therefore, the maintenance characteristic of the timing transmission units is very poor.
- an object of the present invention is to provide a V-type internal combustion engine for a vehicle, which is capable of connecting a primary transmission unit, a starting transmission unit, first and second timing transmission units, and a generator to a crank shaft in a reasonable layout, thereby improving the assembling characteristic and the maintenance characteristic and maintaining a good balance in weight between right and left sides of a vehicular body when the engine is mounted on the vehicle.
- a V-type internal combustion engine for a vehicle in which first and second journals disposed on a crank shaft with a crank portion held therebetween are supported by a crank case via bearings respectively; a front bank and a rear bank disposed in such a manner as to cross each other in a V-shape centered at the crank shaft are sequentially mounted in the crank case; a primary transmission unit for transmitting a power from the crank shaft to a clutch, a starting transmission unit for transmitting a drive force of a starting motor to the crank shaft, first and second timing transmission units for driving valve system cam shafts of the first and second banks respectively, and a generator are connected to the crank shaft; and the crank shaft is disposed laterally in a state that the crank shaft is mounted on the vehicle, characterized in that the first and second timing transmission units adjacent to each other in the axial direction, and the generator adjacent to the outer side of the first and second timing transmission units are connected to one end portion, projecting outward
- the front and rear timing transmission units can be assembled collectively on one end side of the crank shaft, the assembling performance thereof can be enhanced. Also, the maintenance of both the first and second timing transmission units can be easily performed without any interference with other parts only by removing the generator positioned outside both the timing transmission units from the crank shaft. Further, since the generator is disposed adjacent to both the timing transmission units, oil scattered from both the timing transmission units is splashed to the generator during operation of the engine, to thereby effectively cool the generator.
- the front and rear timing transmission units and the generator are disposed on the one side portion of the crank case while the starting transmission unit, the first transmission unit, and the clutch are disposed on the other side portion of the crank case, so that good balance in weight is maintained between both sides of the crank case. Accordingly, when the engine is mounted on the vehicle, it is possible to easily offer good balance in weight between the right and left sides of the vehicle.
- the crank case is composed of first and second case halves divided along a plane perpendicular to the axial line of the crank shaft; the first and second journals of the crank shaft of the crank shaft are fitted to the first and second case halves via ball bearings respectively; and an outside diameter of each of drive timing sprockets of the first and second timing transmission units fixed on the one end portion of the crank shaft is set to be smaller than an inside diameter of the ball bearing in which the first journal is fitted.
- the crank shaft can be assembled in the right and left halves of the crank case after the drive timing sprockets of the first and second timing transmission units are fixed to one end portion of the crank shaft. Accordingly, the drive sprockets can be mounted to the crank shaft as a single product. In particular, the drive sprockets can be press-fitted to the one end portion of the crank shaft with desirable workability.
- the primary transmission unit is offset on the axial end side more than the starting transmission unit; a pump drive gear meshing with a drive gear of the primary transmission unit is fixed at an intermediate portion of a pump shaft which is supported on the crank case in such a manner as to be in parallel to the crank shaft; and a lubricating oil pump disposed in parallel to an overrunning clutch of the starting transmission unit is connected to one end of the pump shaft and a cooling water pump is connected to the other end of the pump shaft.
- the drive gear of the primary transmission unit is used for driving the oil pump and the water pump and both the pumps are driven by a common shaft, the configuration of the engine can be simplified. Further, since the oil pump is disposed adjacent to the over-running clutch in the radial direction, it is possible to suppress the increase in lateral width of the internal combustion engine, although the oil pump and the water pump are coaxially disposed.
- the first and second timing transmission units adjacent to each other in the axial direction, and the generator adjacent to the outer side of the first and second timing transmission units are connected to one end portion, projecting outwardly from the first journal, of the crank shaft, and the primary transmission unit and the starting transmission unit are connected to the other end, projecting outwardly from the second journal, of the crank shaft. Accordingly, it is possible to collectively assemble the front and rear timing transmission units on one end side of the crank shaft, and hence to improve the assembling performance thereof. Also, it is possible to easily carry out the maintenance of both the timing transmission units only by removing the generator positioned outside both the timing transmission units from the crank shaft, and hence to improve the maintenance characteristic thereof.
- the generator is disposed adjacent to both the timing transmission units, oil scattered from both the timing transmission units is splashed to the generator during operation of the engine, to thereby effectively cool the generator. Further, good balance in weight is maintained between both sides of the crank case, and accordingly, when the engine is mounted on the vehicle, good balance in weight between the right and left sides of the vehicle can be easily maintained.
- the crank case is composed of first and second case halves divided along a plane perpendicular to the axial line of the crank shaft; the first and second journals of the crank shaft of the crank shaft are fitted to the first and second case halves via ball bearings respectively; and an outside diameter of each of drive timing sprockets of the first and second timing transmission units fixed on the one end portion of the crank shaft is set to be smaller than an inside diameter of the ball bearing in which the first journal is fitted. Accordingly, the crank shaft can be assembled in the right and left halves of the crank case after the drive timing sprockets are fixed to one end portion of the crank shaft. This makes it possible to mount the drive sprockets to the crank shaft as a single product, and hence to improve the workability in mounting the drive sprockets.
- the primary transmission unit is offset on the axial end side more than the starting transmission unit; a pump drive gear meshing with a drive gear of the primary transmission unit is fixed at an intermediate portion of a pump shaft which is supported on the crank case in such a manner as to be in parallel to the crank shaft; and a lubricating oil pump disposed in parallel to an over-running clutch of the starting transmission unit is connected to one end of the pump shaft and a cooling water pump is connected to the other end of the pump shaft. Accordingly, the oil pump and the water pump can be driven by a common shaft, so that the configuration of the engine can be simplified. Further, since the oil pump is disposed adjacent to the over-running clutch in the radial direction, it is possible to suppress the increase in lateral width of the internal combustion engine, although the oil pump and the water pump are coaxially disposed.
- the front, rear, right, and left sides are based on a body of the motorcycle.
- a front fork (not shown in Figs. 1 and 2) for supporting a front wheel is steerably connected to the front end of a body frame 1 of a motorcycle M.
- a rear fork 3 for supporting a rear wheel 2 is vertically swingably connected to a rear portion of the body frame 1, and a rear cushion 7 is interposed between the rear ends of the rear fork 3 and the body frame 1.
- a V-type internal combustion engine E having a front bank 4 1 and a rear band 4 2 is mounted on an intermediate portion of the body frame 1, and a fuel tank 5 is mounted on the intermediate portion of the body frame 1 at a position over the engine E.
- a main seat 6a and a pillion seat 6b are mounted on the rear portion of the body frame 1 in such a manner as to be continuous to the rear end of the fuel tank 5.
- a chain transmission unit 10 for connecting an output shaft 97 of a transmission 8 connected to the internal combustion engine E and a hub of the rear wheel 2 is disposed on the left side of the rear wheel 2.
- a starting motor 11 is disposed in front of and under the crank shaft 15.
- a front carburetor 12 1 connected to the front bank 4 1 and a rear carburetor 12 2 connected to the rear bank 4 2 are disposed in a valley portion 28 between the front bank 4 1 and the rear band 4 2 of the internal combustion engine E.
- a front exhaust pipe 13 1 connected to a front surface portion of the front bank 4 1 and a rear exhaust pipe 13 2 connected to a rear portion of the rear bank 4 2 are collectively connected to the front end of a common exhaust muffler 14.
- the exhaust muffler 14 is disposed opposite to the chain transmission unit 10 with respect to the rear wheel 2, that is, on the right side of the rear wheel 2.
- the front bank 4 1 and the rear bank 4 2 of the internal combustion engine E are disposed fore and aft in such a manner as to cross each other at 90° centered at a crank shaft 15 extending from right to left.
- the crank shaft 15 has a single crank portion 16 having a crank pin 16a, and a pair of right and left journals 18 and 17 adjacent to both the ends of the crank shaft 15.
- the journals 18 and 17 are supported by a crank case 21 via ball bearings 20 and 19, respectively.
- the front bank 4 1 and the rear bank 4 2 include cylinder blocks 22 1 and 22 2 connected to the front and rear sloping surfaces of a cone-shaped upper portion of the crank case 21 supporting the crank shaft 15, and cylinder heads 23 1 and 23 2 connected to upper ends of the cylinder blocks 22 1 and 22 2 , respectively.
- Water jackets 24 1 and 24 2 which are continuous to each other, are formed in the cylinder blocks 22 1 and 22 2 and cylinder heads 23 1 and 23 2 , respectively.
- Pistons 26 1 and 26 2 inserted in cylinder bores 25 1 and 25 2 of the cylinder blocks 22 1 and 22 2 are connected to the crank pin 16a via connecting rods 27 1 and 27 2 , respectively.
- the connecting rod 27 2 of the rear bank 4 2 is connected to the crank pin 16a in such a manner as to be offset leftwardly from the connecting rod 27 1 of the front bank 4 1 .
- the axial line of the rear bank 4 2 is offset leftwardly from that of the front bank 4 1 in accordance with a lateral offset S, as shown in Fig. 8, between the connecting rods 27 1 and 27 2 .
- an over-running clutch 53 of a starting transmission unit 94, and a drive gear 54a of a first transmission unit 54 connected to a clutch 100 are mounted to a right end portion, projecting outwardly from the right journal 18, of the crank shaft 15 in such a manner as to be adjacently positioned in this order from the inside of the right end portion of the crank shaft 15.
- an outer member of the over-running clutch 53 is spline-connected to the crank shaft 15, and a starting gear 52 is fixed to an inner member of the over-running clutch 53.
- the drive gear 54a is key-connected to the crank shaft 15.
- a drive timing sprocket 42 1 of a front timing transmission unit 46 1 for driving a valve system cam shaft 41 1 of the front bank 4 1 , a drive timing sprocket 42 2 of a rear timing transmission unit 46 2 for driving a valve system cam shaft 41 2 of the rear bank 4 2 , and a rotor 31 of a generator 30 are mounted on a left end portion, projecting outwardly from the left journal 17, of the crank shaft 15 in such a manner as to be adjacently positioned in this order from the inside of the left end portion of the crank shaft 15.
- the rotor 31 is key-connected to the crank shaft 15.
- the mounting structure of the two drive timing sprockets 42 1 and 42 2 will be described later.
- a projection 35 is formed at a portion on the outer peripheral surface of the rotor 31.
- a crank position sensor 36 for detecting a rotational position of the crank shaft 15 in cooperation with the projection 35 is fixed to the left end surface of the crank case 21.
- An output signal sent from the crank position sensor 36 is used as a control signal for an ignitor or an input signal for a tachometer.
- the starting gear 52 is supported thereon via the over-running clutch 53 in such a manner as to be adjacent to the right journal 18, and the first drive gear 54a is key-connected thereto in such a manner as to be adjacent to the starting gear 52.
- the front and rear timing transmission units 46 1 and 46 2 can be collectively assembled on the same side, that is, on the left end portion side of the crank shaft 15, to thereby improve the assembling performance thereof, and also the maintenance of both the timing transmission units 46 1 and 46 2 can be easily performed without any interference with other parts only by removing the generator 30 positioned outside both the timing transmission units 46 1 and 46 2 from the crank shaft 15. Further, since the generator 30 is disposed adjacent to both the timing transmission units 46 1 and 46 2 , oil scattered from both the timing transmission units 46 1 and 46 2 are splashed to the generator 30 during operation of the engine, it is possible to effectively cool the generator 30.
- the front and rear timing transmission units 46 1 and 46 2 and the generator 30 are disposed on the left side portion of the crank case 21 while a starting transmission unit 94, the first transmission unit 54, and the clutch 100 are disposed on the other side of the crank case 21, so that good balance in weight is maintained between both sides of the crank case 21 and accordingly, when the internal combustion engine is mounted on the body frame 1, it is possible to easily offer good balance in weight between the right and left sides of the motorcycle M.
- Intake valves 37 1 and 37 2 and exhaust valves 38 1 and 38 2 are respectively provided in the cylinder heads 23 1 and 23 2 of the front and rear banks 4 1 and 4 2 in such a manner that the intake valves 37 1 and 37 2 are offset to the valley 28 side between the front and rear banks 4 1 and 4 2 .
- Both ends of cam shafts 41 1 and 41 2 extending in parallel to the crank shaft 15 are supported by the cylinder heads 23 1 and 23 2 via ball bearings 50 and 50', respectively.
- the cam shaft 41 1 is adapted to open/close the intake valve 37 1 and the exhaust valve 38 1 via rocker arms 39 1 and 40 1 , respectively, and the cam shaft 41 2 is adapted to open/close the intake valve 37 2 and the exhaust valve 38 2 via rocker arms 39 2 and 40 2 , respectively.
- Timing chains 44 1 and 44 2 are wound around the drive timing sprockets 42 1 and 42 2 fixed to the left end portion of the crank shaft 15 and driven timing sprockets 43 1 and 43 2 fixed to the left ends of the cam shafts 41 1 and 41 2 of the front and rear banks 4 1 and 4 2 , respectively.
- Both the drive timing sprockets 42 1 and 42 2 has a common boss 45 press-fitted around a portion, adjacent to the outer end of the left journal 17, of the crank shaft 15.
- the drive timing sprockets 42 1 , the timing chain 44 1 and the driven timing sprocket 43 1 of the front bank 4 1 constitute the front timing transmission unit 46 1 for reducing the rotational speed of the crank shaft 15 to half and transmitting the reduced rotational speed to the corresponding cam shaft 41 1 .
- the front timing transmission unit 46 1 is disposed in a front timing transmission chamber 47 1 formed in a side wall, on the generator 30 side, of the front bank 4 1 .
- the drive timing sprockets 42 2 , the timing chain 44 2 and the driven timing sprocket 43 2 of the rear bank 4 2 constitute the rear timing transmission unit 46 2 for reducing the rotational speed of the crank shaft 15 to half and transmitting the reduced rotational speed to the corresponding cam shaft 41 2 .
- the rear timing transmission unit 46 2 is disposed in a rear timing transmission chamber 47 2 formed in a side wall, on the generator 30 side, of the rear bank 4 2 .
- the rear timing transmission unit 46 2 is disposed outside the front timing transmission unit 46 1 in the axial direction, that is, it is located closer to the generator 30 than the front timing transmission unit 46 1 is.
- the crank shaft 15 is rotated counterclockwise as shown by an arrow R in Fig. 4, and accordingly, the rear sides of the timing chains 44 1 and 44 2 are loosened.
- arched chain tensioners 48 1 and 48 2 swingably supported by the crank case 21 are brought into slide-contact with the loosened rear sides of the timing chains 44 1 and 44 2 .
- known tensioner lifters 49 1 and 49 2 for pressing central portions of the chain tensioners 48 1 and 48 2 in the longitudinal direction toward the timing chains 44 1 and 44 2 at specific loads are mounted on mounting planes formed on rear surfaces of the cylinder blocks 22 1 and 22 2 of the front and rear banks 4 1 and 4 2 with bolts 109, respectively.
- the crank case 21 is divided at the central portion in the lateral direction into a right case half 21b and a left case half 21a.
- Outer races of the ball bearings 20 and 19 are previously lightly press-fitted in the right and left case halves 21b and 21a, respectively, and upon assembly of both the case halves 21b and 21a, the right and left journals 18 and 17 of the crank shaft 15 are lightly press-fitted in inner races of the ball bearings 20 and 19, respectively.
- an outside diameter d 1 of each of the drive timing sprockets 42 1 and 42 2 is set to be slightly smaller than an inside diameter d 2 of the inner race of the ball bearing 19.
- the ball bearings 20 and 19 are lightly press-fitted in the right and left case halves 21b and 21a and the right and left crank journals 18 and 17, it is possible to suppress occurrence of vibration of the ball bearings 20 and 19 and hence reduce occurrence of noise during operation of the engine.
- the exit of an exhaust port 51 1 of the front bank 4 1 is opened to the front of the cylinder head 23 1 of the front bank 4 1 , and the upstream end of the front exhaust pipe 13 1 is connected to the exit of the exhaust port 51 1 .
- the exit of an exhaust port 51 2 of the rear bank 4 2 is opened to a right side surface, opposed to the rear timing transmission unit 46 2 , of the rear portion of the cylinder head 23 2 of the rear bank 4 2 , and the upstream end of the rear exhaust pipe 13 2 is connected to the exit of the exhaust port 51 2 .
- the front and rear exhaust pipe 13 1 and 13 2 arranged on the upper and lower sides extend on the right side, opposed to the front and rear chain transmission units 46 1 and 46 2 , of the internal combustion engine E, and the downstream ends of the front and rear exhaust pipe 13 1 and 13 2 are collected and connected to the exhaust muffler 14 disposed on the right side of the rear wheel 2.
- the rear exhaust pipe 13 2 disposed on the right side of the motorcycle M is connected to the exhaust port 51 2 opened to the right side surface of the rear portion of the cylinder head 23 2 of the rear bank 4 2 , the degree of bending of the rear exhaust pipe 13 2 is reduced, so that it is possible to make small the flow resistance of the pipe and hence to improve the output performance.
- a mission case portion 95 protruded from a lower portion of the rear bank 4 2 is formed integrally with the crank case 21.
- An input shaft 96 and an output shaft 97 of the transmission 8, which are provided directly behind the crank shaft 15 in such a manner as to be located on the front and rear sides in parallel to the crank shaft 15, are contained in the mission case portion 95.
- Both ends of the input shaft 96 are supported by right and left walls of the mission case portion 95 via a pair of ball bearings 98' and 98, and both ends of the output shaft 97 are supported by the right and left walls of the mission case portion 95 via a pair of ball bearings 99' and 99.
- An inner member 101 of the clutch 100 covered with the right cover 34 connected to the right side surface of the crank case 21 is spline-connected to the right end portion of the input portion 96.
- a first driven gear 54b which is meshed with the first drive gear 54a to constitute the first transmission unit 54, is mounted to the inner end of the outer member 102.
- a plurality (five in the example shown in the figures) of speed change gear trains G 1 to G 5 are selectively arranged between the input shaft 96 and the output shaft 97.
- a left wall 95a, which supports the left end portions of the input shaft 96 and the output shaft 97, of the mission case portion 95 is offset rightwardly from the timing transmission unit 46 2 of the rear bank 4 2 . Accordingly, when the tensioner lifter 49 2 of the timing transmission unit 46 2 of the rear bank 4 2 is mounted on the rear surface of the cylinder block 22 2 of the rear bank 4 2 , it is possible to prevent the tensioner lifter 49 2 from interfering with the mission case portion 95.
- timing transmission unit 46 2 of the rear bank 4 2 is disposed outwardly, that is, leftwardly from the timing transmission unit 46 1 of the front bank 4 1 , it is possible to minimize the rightward offset of the mission case portion 95 from the crank case 21, and hence to realize the compactness of the internal combustion engine E.
- the rear wall of the mission case portion 95 has a mounting hole 103, and a vehicular speed sensor 105 having a detecting portion 105a inserted in the mission case portion 95 through the mounting hole 103 is fixed on the rear wall of the mission case portion 95 with a bolt 110.
- the vehicular speed sensor 105 is disposed with the detecting portion 105a facing to the tips of a top driven gear, that is, a driven gear 104 of the top gear train G 5 .
- the top driven gear 104 which is spline-connected to the output shaft 97, serves as a shift gear for working the second-speed gear train G 2 by leftward shift thereof.
- the vehicular speed sensor 105 creates a signal corresponding to the number of teeth of the top driven gear 104 just crossing the detecting portion of the vehicular speed sensor 105 and outputs the signal to a computer (not shown) .
- the computer calculates a vehicular speed on the basis of the signal thus inputted from the vehicular speed sensor 105 and displays the vehicular speed on a speed meter (not shown) on an instrument panel (not shown) of the motorcycle M.
- the vehicular speed sensor 105 for detecting the rotational speed of the top driven gear 104 usually rotated together with the output shaft 97 can be mounted on the rear wall of the mission case portion 95 without any interference with not only the rear bank 4 2 tilted rearwardly toward the mission case portion 95 side but also the rear exhaust pipe 13 2 mounted on the rear portion of the rear bank 4 2 .
- a rib 106 for covering the lower surface of the vehicular speed sensor 105 is integrally formed on the rear surface of the mission case portion 95.
- the central portion of the rib 106 has a through-hole 107 allowing a lead wire 108 of the vehicular speed sensor 105 to pass therethrough.
- a pair of right and left hangers 112 1 and a pair of right and left hangers 112 2 are integrally formed on the upper and lower sides of the rear surface of the mission case portion 95 in such a manner as to project therefrom, and a pair of right and left hangers 112 3 are integrally formed on the front surface of the crank case 21 in such a manner as to project therefrom.
- these hangers 112 1 , 112 2 , and 112 3 are connected to the body frame 1.
- the vehicular speed sensor 105 is disposed in a rear dead space of the interior of the mission case portion 95 surrounded by the rear side two pairs of the hangers 112 1 and 112 2 . With this configuration, it is possible to enhance the space efficiency.
- the above rib 106 functions to protect the vehicular speed sensor 105 from being affected by small stones and sands flying from a road during running of the motorcycle M.
- the through-hole 107 for allowing the lead wire 108 to pass therethrough functions as a port for discharging rainwater and cleaning water permeated in the rib 106.
- the first drive gear 54a key-connected to the right end portion of the crank shaft 15 is meshed at its two different portions in the peripheral direction with a pump drive gear 56 and the first driven gear 54b.
- the pump drive gear 56 is key-connected to a pump shaft 61 which is supported via a bearing 86 by the right cover 34 connected to the right end surface of the crank case 21.
- the pump shaft 61 which is in parallel to the crank shaft 15, is disposed in front of and over the crank shaft 15.
- An inner rotor 58 of a trochoid type oil pump 57 for lubrication is fixed on the inner end of the pump shaft 61, and an impeller 63 of a water pump 62 for cooling is fixed on the outer end of the pump shaft 61.
- a pump housing 60 for containing an outer rotor 59 of the oil pump 57 is screwed in a partition wall 65 for supporting the ball bearing 20 of the crank case 21.
- a pump casing 64 for containing the impeller 63 is fixed on the outer surface of the right cover with a bolt 87.
- the oil pump 57 and the water pump 62 are coaxially disposed in front of and over the crank shaft 15.
- the oil pump 57 is provided on the crank case 21 in such a manner as to be adjacent to the outer side of the over-running clutch 53 in the radial direction.
- a suction port of the oil pump 57 is connected via a suction pipe 68 to a strainer 67 (see Fig. 2) disposed in an oil sump 66 on the inner bottom of the crank case 21, and a discharge port of the oil pump 57 is communicated via an oil passage 69 to the crank shaft 15, the cam shafts 41 1 and 41 2 of the front and rear banks 4 1 and 4 2 , and other portions to be lubricated.
- An oil filter 70 positioned substantially directly over the crank shaft 15 is interposed in the course of the oil passage 69.
- the oil filter 70 is mounted to a filter chamber 71 formed in the right cover 34, and a cap 72 for closing an opening of the chamber 71 is fixed to the right cover 34.
- An inlet chamber 71a on the outer peripheral side of the oil filter 70 in the filter chamber 71 is communicated to the discharge port of the oil pump 57 via an upstream portion 69a of the oil passage 69 formed in the crank case 21, and an outlet chamber 71b on the inner peripheral side of the oil filter 70 in the filter chamber 71 is communicated to two branch oil passages 69b and 69c, formed in the cap 72, of the oil passage 69.
- One branch oil passage 69b is communicated to a portion 73 to be lubricated of the crank shaft 15 system.
- the other branch oil passage 69c is further branched at a connection surface between the crank case 21 and the right cover 34 into front and rear branch oil passages 69d and 69e which are in turn communicated to portions 74 1 and 74 2 to be lubricated of the valve systems including the cam shafts 41 1 and 41 2 of the front and rear banks 4 1 and 4 2 .
- the oil filter 70 is provided with a relief valve 70b for short-circuiting the inlet chamber 71a to the outlet chamber 71b when a filter element 70a of the oil filter 70 becomes blocked.
- a suction pipe 75 is connected to an outlet of the radiator 29 (disposed in front of the internal combustion engine E as shown in Fig. 1) via a water pipe 77 1 , and a discharge pipe 76 is connected to a lower portion of the water jacket 24 1 of the front bank 4 1 via a water pipe 77 2 .
- the front and rear banks 4 1 and 4 2 include the cylinder blocks 22 1 and 22 2 , the cylinder heads 23 1 and 23 2 , and the water jacket 24 1 and 24 2 continuous to each other, respectively, and a combined chamber 80 opened to the front surface of the cylinder head 23 2 of the rear bank 4 2 is formed in the cylinder head 23 2 and an upper portion of the water jacket 24 2 is communicated to the combined chamber 80.
- Lower joints 78 1 and 78 2 communicated to lower portions of the corresponding water jackets 24 1 and 24 2 are integrally formed on the opposed surfaces of the front and rear banks 4 1 and 4 2 in such a manner as to project therefrom. Both ends of a lower communication water pipe 77 3 disposed in the valley portion 28 are connected to these joints 78 1 and 78 2 .
- An upper joint 79 1 communicated to an upper portion of the jacket 23 1 is integrally formed on the rear surface of the front bank 4 1 , and a flange of an upper joint 79 2 communicated to the combined chamber 80 is screwed in a lower surface portion of the cylinder head 23 2 of the rear bank 4 2 . Both ends of a rear communication water pipe 77 4 disposed in the valley portion 28 are connected to these upper joints 79 1 and 79 2 .
- a thermostat 82 is disposed in the combined chamber 80, and a thermostat cover 81 for holding the thermostat 82 and covering the opening of the combined chamber 80 is connected to the front surface of the cylinder head 23 2 .
- An outlet joint 83 connected to the outlet of the thermostat 82 is integrally formed on the thermostat cover 81.
- the outlet joint 83 is connected to the inlet of the radiator 29 via a water pipe 77 5 .
- a bypass outlet joint 84 communicated to the combined chamber 80 via a communication passage 84' is integrally formed on the upper joint 79 2 .
- the bypass outlet joint 84 is communicated to a heating chamber of the carburetor 12 2 of the rear bank 4 2 , a heating chamber of the carburetor 12 1 of the front bank 4 1 , and the suction pipe 75 in sequence by way of a bypass water pipe 85.
- the bypass outlet joint 84 has an inside diameter sufficiently smaller than that of the outlet joint 83 of the thermostat cover 81.
- the thermostat 82 blocks the combined chamber 80 from the thermostat cover 81 and opens the communication passage 84' between the combined chamber 80 and the bypass outlet joint 84.
- the thermostat 82 communicates the combined chamber 80 to the thermostat cover 81 and closes the communication passage 84'.
- the thermostat 82 blocks the combined chamber 80 from the thermostat cover 81 and opens the communication passage 84'. Consequently, cooling water is fed first from the discharge pipe 76 to the water jacket 24 1 of the front bank 4 1 by the water pump 62.
- about a half of the cooling water is immediately fed to the water jacket 24 2 of the rear bank 4 2 by way of the lower communication water pipe 77 3 , and the remaining cooling water passes through the water jacket 24 1 of the front bank 4 1 and is then fed to the combined chamber 80 of the rear bank 4 2 by way of the upper communication water pipe 77 4 .
- the cooling water is combined with the above cooling water having passed through the water jacket 24 2 of the rear bank 4 2 .
- the cooling water thus combined is fed from the combined chamber 80 to the bypass outlet joint 84 by way of the communication passage 84', being further fed from the bypass outlet joint 84 to the heating chambers of the carburetors 12 2 and 12 1 of the rear and front banks 4 2 and 4 1 in sequence, and is returned to the suction pipe 75 of the water pump 62. Thereafter, the same circulation is repeated.
- Such circulation of cooling water not by way of the radiator 29 makes it possible to promote the warming of the internal combustion engine E, and to heat the carburetors 12 1 and 12 2 thereby preventing icing of a fuel nozzle and its neighborhood.
- the temperature of the cooling water whose components having passed through the water jackets 24 1 and 24 2 of the front and rear banks 4 1 and 4 2 and combined in the combined chamber 80 becomes the above specific temperature.
- the thermostat 82 since the thermostat 82 communicates the combined chamber 80 to the thermostat cover 81 and closes the communication passage 84', the above cooling water flows on the outlet joint 83 side, and is returned to the suction pipe 75 of the water pump 62 by way of the radiator 29. Thereafter, the same circulation is repeated. Accordingly, the front and rear banks 4 1 and 4 2 can be effectively cooled with the cooling water cooled by the radiation action of the radiator 29.
- the lower and upper communication water pipes 77 3 and 77 4 are sufficient to be relatively short in length and are disposed in the valley portion 28 between both the banks 4 1 and 4 2 , they are hidden by both the banks 4 1 and 4 2 .
- the water pipes 77 3 and 77 4 therefore, are inconspicuous as seen from the outside, that is, do not degrade the appearance of the internal combustion engine E.
- the thermostat 82 Since the thermostat 82 is disposed in the combined chamber 80 in which components of cooling water having cooled the front and rear banks 4 1 and 4 2 are combined, it can suitably control the water temperature in both the banks 4 1 and 4 2 by certainly detecting an average water temperature in both the banks 4 1 and 4 2 . Further, it is not required to make a layout of piping for the thermostat 82, thereby simplifying the entire piping layout.
- thermostat cover 81 including the outlet joint 83 projecting forwardly is connected to the front surface of the upper portion of the rear bank 4 2 , it is possible to reduce the degree of bending of the water pipe 77 5 for communicating the outlet joint 83 to the inlet of the radiator 29, and hence to make small the flow resistance of the water pipe 77 5 and also improve the entire appearance of the internal combustion engine E.
- bypass outlet joint 84 having the inside diameter smaller than that of the upper joint 79 2 of the rear bank 4 2 and being communicated to the combined chamber 80 is integrally formed on the upper joint 79 2 , it is possible to collectively mount the upper joint 79 2 and the bypass outlet joint 84 to the rear bank 4 2 , and hence to simplify the piping works.
- the oil pump 57 is disposed adjacent to the over-running clutch 53 in the radial direction, it is possible to suppress the increase in lateral width of the internal combustion engine E, although the oil pump 57 and the water pump 62 are coaxially disposed.
- crank case 21 Since the oil pump 57 and the water pump 62 are disposed in front of and over the crank shaft 15, it is possible to compactly form the rear portion of the crank case 21 and the mission case portion 95 continuous thereto without any interference with the oil pump 57 and the water pump 62, and hence to ensure a desirable ground clearance of the internal combustion engine E and easily reduce the heights of the driver's seat 6a and the pillion seat 6b.
- the front portion of the crank case 21 is slightly swelled by the effect of the above arrangement of the oil pump 57 and the water pump 62, the swelled portion of the crank case 21 is contained in the lower dead space of the front bank 4 1 , and therefore, it does not obstruct the compactness of the internal combustion engine E.
- the input shaft 96 and the output shaft 97 of the transmission 8 are horizontally disposed directly after the crank shaft 15 without any interference with the oil pump 57 and the water pump 62, it is possible to achieve the compactness of the mission case portion 95 and also flatten the upper wall of the mission case portion 95. This makes it possible to sufficiently ensure the distance between the mission case portion 95 and the rear exhaust pipe 13 2 and hence to easily prevent the mission case portion 95 and the transmission 8 contained therein from being thermally affected by the rear exhaust pipe 13 2 .
- a containing recessed portion 88 is formed in the bottom surface of the front portion of the crank case 21, and the starting motor 11 is disposed in the containing recessed portion 88 with its axial line directed in parallel to the crank shaft 15.
- a casing 89 of the starting motor 11 is mounted on the crank case 21 in such a manner that a cylindrical supporting portion 89a at one end of the casing 89 is liquid-tightly fitted in a through-hole 90 formed in the end wall of the containing recessed portion 88 and a mounting arm portion 89b at the other end of the casing 89 is fastened to the crank case 21 with a bolt 111.
- the leading end of a rotor shaft 91 of the starting motor 11 is inserted in the crank case 21, and a pinion 92 formed on the leading end of the rotor shaft 91 is adapted to drive the starting gear 52 via a reduction gear train 93.
- the starting gear 52, the over-running clutch 53, and the reduction gear train 93 constitute a starting transmission unit 94 for transmitting the rotational power of the starting motor 11 to the crank shaft 15.
- the starting motor 11 since the starting motor 11 is disposed in front of and under the crank shaft 15, the starting motor 11 also does not obstruct the compactness of the rear portion of the crank case 21 and the mission case portion 95, and since the starting motor 11 is contained in the lower dead space of the front bank 4 1 , it does not obstruct the compactness of the internal combustion engine E. Further, the reduction gear train 93 is dipped in oil accumulated in the oil sump 66 on the bottom of the crank case 21 by the effect of the above arrangement of the starting motor 11; however, since the reduction gear train 93 is activated not during operation of the engine but upon start-up of the engine, it does not agitate the oil during operation of the engine and thereby does not cause the power loss.
- Object To provide a V-type internal combustion engine for a vehicle, which is capable of connecting a primary transmission unit, a starting transmission unit, first and second timing transmission units, and a generator to a crank shaft in a reasonable layout, thereby improving the assembling characteristic and the maintenance characteristic and maintaining a good balance in weight between right and left sides of a vehicular body when the engine is mounted on the vehicle.
- First and second timing transmission units 46 1 and 46 2 adjacent to each other in the axial direction, and a generator 30 adjacent to the outer side of the first and second timing transmission units 46 1 and 46 2 are connected to one end portion, projecting outwardly from a first journal 17, of a crank shaft 15, and a primary transmission unit 54 and a starting transmission unit 94 are connected to the other end, projecting outwardly from a second journal 18, of the crank shaft 15.
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Lubrication Of Internal Combustion Engines (AREA)
- Cylinder Crankcases Of Internal Combustion Engines (AREA)
- Arrangement Of Transmissions (AREA)
Abstract
Description
- The present invention relates to a V-type internal combustion engine for a vehicle which is mounted to such as a motorcycle, and particularly to an improved V-type internal combustion engine for a vehicle, in which first and second journals disposed on a crank shaft with a crank portion held therebetween are supported by a crank case via bearings respectively; a front bank and a rear bank disposed in such a manner as to cross each other in a V-shape centered at said crank shaft are sequentially mounted in the crank case; a primary transmission unit for transmitting a power from said crank shaft to a clutch, a starting transmission unit for transmitting a drive force of a starting motor to said crank shaft, first and second timing transmission units for driving valve system cam shafts of said first and second banks respectively, and a generator are connected to said crank shaft; and said crank shaft is disposed laterally in a state that the crank shaft is mounted on said vehicle.
- The V-type internal combustion engine for a vehicle of this type has been known, for example, from Japanese patent Laid-open No. Sho 64-83912, in which a first timing transmission unit, a starting transmission unit and a generator are connected to one end portion, projecting outwardly from a first journal, of a crank shaft, and a second timing transmission unit and primary transmission unit are connected to the other end portion, projecting outwardly from a second journal, of the crank shaft.
- The above-described prior art configuration, however, has a problem that since the first and second timing transmission units are connected to both the end portions of the crank shaft, the assembling characteristic of the first and second timing units becomes degraded. Another problem is that since the starting transmission unit and the generator are disposed outside one timing transmission unit while the primary transmission unit is disposed outside the other timing transmission unit, the generator and the units disposed outside the timing transmission units must be removed for carrying out the maintenance of the timing transmission units. Therefore, the maintenance characteristic of the timing transmission units is very poor.
- In view of the foregoing, the present invention has been made, and an object of the present invention is to provide a V-type internal combustion engine for a vehicle, which is capable of connecting a primary transmission unit, a starting transmission unit, first and second timing transmission units, and a generator to a crank shaft in a reasonable layout, thereby improving the assembling characteristic and the maintenance characteristic and maintaining a good balance in weight between right and left sides of a vehicular body when the engine is mounted on the vehicle.
- To achieve the above object, according to a first feature of the present invention, there is provided a V-type internal combustion engine for a vehicle, in which first and second journals disposed on a crank shaft with a crank portion held therebetween are supported by a crank case via bearings respectively; a front bank and a rear bank disposed in such a manner as to cross each other in a V-shape centered at the crank shaft are sequentially mounted in the crank case; a primary transmission unit for transmitting a power from the crank shaft to a clutch, a starting transmission unit for transmitting a drive force of a starting motor to the crank shaft, first and second timing transmission units for driving valve system cam shafts of the first and second banks respectively, and a generator are connected to the crank shaft; and the crank shaft is disposed laterally in a state that the crank shaft is mounted on the vehicle, characterized in that the first and second timing transmission units adjacent to each other in the axial direction, and the generator adjacent to the outer side of the first and second timing transmission units are connected to one end portion, projecting outwardly from the first journal, of the crank shaft, and the primary transmission unit and the starting transmission unit are connected to the other end, projecting outwardly from the second journal, of the crank shaft.
- According to the first feature described above, since the front and rear timing transmission units can be assembled collectively on one end side of the crank shaft, the assembling performance thereof can be enhanced. Also, the maintenance of both the first and second timing transmission units can be easily performed without any interference with other parts only by removing the generator positioned outside both the timing transmission units from the crank shaft. Further, since the generator is disposed adjacent to both the timing transmission units, oil scattered from both the timing transmission units is splashed to the generator during operation of the engine, to thereby effectively cool the generator.
- Further, the front and rear timing transmission units and the generator are disposed on the one side portion of the crank case while the starting transmission unit, the first transmission unit, and the clutch are disposed on the other side portion of the crank case, so that good balance in weight is maintained between both sides of the crank case. Accordingly, when the engine is mounted on the vehicle, it is possible to easily offer good balance in weight between the right and left sides of the vehicle.
- According to a second feature of the present invention, in addition to the above feature, the crank case is composed of first and second case halves divided along a plane perpendicular to the axial line of the crank shaft; the first and second journals of the crank shaft of the crank shaft are fitted to the first and second case halves via ball bearings respectively; and an outside diameter of each of drive timing sprockets of the first and second timing transmission units fixed on the one end portion of the crank shaft is set to be smaller than an inside diameter of the ball bearing in which the first journal is fitted.
- According to the second feature described above, the crank shaft can be assembled in the right and left halves of the crank case after the drive timing sprockets of the first and second timing transmission units are fixed to one end portion of the crank shaft. Accordingly, the drive sprockets can be mounted to the crank shaft as a single product. In particular, the drive sprockets can be press-fitted to the one end portion of the crank shaft with desirable workability.
- According to a third feature of the present invention, in addition to the first or second feature, the primary transmission unit is offset on the axial end side more than the starting transmission unit; a pump drive gear meshing with a drive gear of the primary transmission unit is fixed at an intermediate portion of a pump shaft which is supported on the crank case in such a manner as to be in parallel to the crank shaft; and a lubricating oil pump disposed in parallel to an overrunning clutch of the starting transmission unit is connected to one end of the pump shaft and a cooling water pump is connected to the other end of the pump shaft.
- According to the third feature described above, since the drive gear of the primary transmission unit is used for driving the oil pump and the water pump and both the pumps are driven by a common shaft, the configuration of the engine can be simplified. Further, since the oil pump is disposed adjacent to the over-running clutch in the radial direction, it is possible to suppress the increase in lateral width of the internal combustion engine, although the oil pump and the water pump are coaxially disposed.
- As described above, according to the first feature of the present invention, the first and second timing transmission units adjacent to each other in the axial direction, and the generator adjacent to the outer side of the first and second timing transmission units are connected to one end portion, projecting outwardly from the first journal, of the crank shaft, and the primary transmission unit and the starting transmission unit are connected to the other end, projecting outwardly from the second journal, of the crank shaft. Accordingly, it is possible to collectively assemble the front and rear timing transmission units on one end side of the crank shaft, and hence to improve the assembling performance thereof. Also, it is possible to easily carry out the maintenance of both the timing transmission units only by removing the generator positioned outside both the timing transmission units from the crank shaft, and hence to improve the maintenance characteristic thereof. Also, since the generator is disposed adjacent to both the timing transmission units, oil scattered from both the timing transmission units is splashed to the generator during operation of the engine, to thereby effectively cool the generator. Further, good balance in weight is maintained between both sides of the crank case, and accordingly, when the engine is mounted on the vehicle, good balance in weight between the right and left sides of the vehicle can be easily maintained.
- According to the second feature of the present invention, the crank case is composed of first and second case halves divided along a plane perpendicular to the axial line of the crank shaft; the first and second journals of the crank shaft of the crank shaft are fitted to the first and second case halves via ball bearings respectively; and an outside diameter of each of drive timing sprockets of the first and second timing transmission units fixed on the one end portion of the crank shaft is set to be smaller than an inside diameter of the ball bearing in which the first journal is fitted. Accordingly, the crank shaft can be assembled in the right and left halves of the crank case after the drive timing sprockets are fixed to one end portion of the crank shaft. This makes it possible to mount the drive sprockets to the crank shaft as a single product, and hence to improve the workability in mounting the drive sprockets.
- According to the third feature of the present invention, the primary transmission unit is offset on the axial end side more than the starting transmission unit; a pump drive gear meshing with a drive gear of the primary transmission unit is fixed at an intermediate portion of a pump shaft which is supported on the crank case in such a manner as to be in parallel to the crank shaft; and a lubricating oil pump disposed in parallel to an over-running clutch of the starting transmission unit is connected to one end of the pump shaft and a cooling water pump is connected to the other end of the pump shaft. Accordingly, the oil pump and the water pump can be driven by a common shaft, so that the configuration of the engine can be simplified. Further, since the oil pump is disposed adjacent to the over-running clutch in the radial direction, it is possible to suppress the increase in lateral width of the internal combustion engine, although the oil pump and the water pump are coaxially disposed.
- Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
- It is illustrated in:
- Fig. 1 A side view of a motorcycle on which a V-type internal combustion engine of the present invention is mounted.
- Fig. 2 A side view of the internal combustion engine shown in Fig. 1.
- Fig. 3 An enlarged vertical sectional view taken on line 3-3 of Fig. 2.
- Fig. 4 A sectional view taken on line 4-4 of Fig. 3.
- Fig. 5 A sectional view taken on line 5-5 of Fig. 2.
- Fig. 6 A system diagram showing the flow of cooling water in the internal combustion engine.
- Fig. 7 A sectional view taken on line 7-7 of Fig. 2.
- Fig. 8 An enlarged view showing front and rear timing transmission units shown in Fig. 3 and their neighborhoods.
- Fig. 9 An enlarged view of a transmission shown in Fig. 3 and its neighborhood.
- Fig. 10 A plan view showing an exhaust system of the internal combustion engine and its neighborhood.
- Fig. 11 A plan view of a cylinder head of a rear bank of the internal combustion engine.
- Fig. 12
A view seen along an
arrow 12 of Fig. 9. -
- In the following description, the front, rear, right, and left sides are based on a body of the motorcycle.
- A front fork (not shown in Figs. 1 and 2) for supporting a front wheel is steerably connected to the front end of a
body frame 1 of a motorcycle M. Arear fork 3 for supporting arear wheel 2 is vertically swingably connected to a rear portion of thebody frame 1, and a rear cushion 7 is interposed between the rear ends of therear fork 3 and thebody frame 1. - A V-type internal combustion engine E having a
front bank 41 and arear band 42 is mounted on an intermediate portion of thebody frame 1, and afuel tank 5 is mounted on the intermediate portion of thebody frame 1 at a position over the engine E. Amain seat 6a and apillion seat 6b are mounted on the rear portion of thebody frame 1 in such a manner as to be continuous to the rear end of thefuel tank 5. - A
chain transmission unit 10 for connecting anoutput shaft 97 of atransmission 8 connected to the internal combustion engine E and a hub of therear wheel 2 is disposed on the left side of therear wheel 2. Astarting motor 11 is disposed in front of and under thecrank shaft 15. - A
front carburetor 121 connected to thefront bank 41 and arear carburetor 122 connected to therear bank 42 are disposed in avalley portion 28 between thefront bank 41 and therear band 42 of the internal combustion engine E. Afront exhaust pipe 131 connected to a front surface portion of thefront bank 41 and arear exhaust pipe 132 connected to a rear portion of therear bank 42 are collectively connected to the front end of acommon exhaust muffler 14. Theexhaust muffler 14 is disposed opposite to thechain transmission unit 10 with respect to therear wheel 2, that is, on the right side of therear wheel 2. - The
front bank 41 and therear bank 42 of the internal combustion engine E are disposed fore and aft in such a manner as to cross each other at 90° centered at acrank shaft 15 extending from right to left. Thecrank shaft 15 has asingle crank portion 16 having acrank pin 16a, and a pair of right andleft journals crank shaft 15. Thejournals crank case 21 viaball bearings - The
front bank 41 and therear bank 42 include cylinder blocks 221 and 222 connected to the front and rear sloping surfaces of a cone-shaped upper portion of thecrank case 21 supporting thecrank shaft 15, and cylinder heads 231 and 232 connected to upper ends of the cylinder blocks 221 and 222, respectively. Water jackets 241 and 242, which are continuous to each other, are formed in the cylinder blocks 221 and 222 and cylinder heads 231 and 232, respectively. - Pistons 261 and 262 inserted in cylinder bores 251 and 252 of the cylinder blocks 221 and 222 are connected to the crank
pin 16a via connecting rods 271 and 272, respectively. In this case, the connecting rod 272 of therear bank 42 is connected to the crankpin 16a in such a manner as to be offset leftwardly from the connecting rod 271 of thefront bank 41. The axial line of therear bank 42 is offset leftwardly from that of thefront bank 41 in accordance with a lateral offset S, as shown in Fig. 8, between the connecting rods 271 and 272. - As shown in Fig. 5, an over-running
clutch 53 of a startingtransmission unit 94, and adrive gear 54a of afirst transmission unit 54 connected to a clutch 100 are mounted to a right end portion, projecting outwardly from theright journal 18, of thecrank shaft 15 in such a manner as to be adjacently positioned in this order from the inside of the right end portion of thecrank shaft 15. Specifically, an outer member of the over-runningclutch 53 is spline-connected to thecrank shaft 15, and a startinggear 52 is fixed to an inner member of the over-runningclutch 53. Thedrive gear 54a is key-connected to thecrank shaft 15. - As shown in Fig. 8, a
drive timing sprocket 421 of a fronttiming transmission unit 461 for driving a valvesystem cam shaft 411 of thefront bank 41, adrive timing sprocket 422 of a reartiming transmission unit 462 for driving a valvesystem cam shaft 412 of therear bank 42, and arotor 31 of agenerator 30 are mounted on a left end portion, projecting outwardly from theleft journal 17, of thecrank shaft 15 in such a manner as to be adjacently positioned in this order from the inside of the left end portion of thecrank shaft 15. Specifically, therotor 31 is key-connected to thecrank shaft 15. The mounting structure of the twodrive timing sprockets - A
stator 32 of thegenerator 30, which is surrounded by therotor 31, is fixed to aleft cover 33 connected to the left end surface of thecrank case 21. - A
projection 35 is formed at a portion on the outer peripheral surface of therotor 31. A crankposition sensor 36 for detecting a rotational position of thecrank shaft 15 in cooperation with theprojection 35 is fixed to the left end surface of thecrank case 21. An output signal sent from thecrank position sensor 36 is used as a control signal for an ignitor or an input signal for a tachometer. - At the right end portion, opposed to the
generator 30, of thecrank shaft 15, the startinggear 52 is supported thereon via the over-runningclutch 53 in such a manner as to be adjacent to theright journal 18, and thefirst drive gear 54a is key-connected thereto in such a manner as to be adjacent to the startinggear 52. - With this configuration, the front and rear
timing transmission units crank shaft 15, to thereby improve the assembling performance thereof, and also the maintenance of both thetiming transmission units generator 30 positioned outside both thetiming transmission units crank shaft 15. Further, since thegenerator 30 is disposed adjacent to both thetiming transmission units timing transmission units generator 30 during operation of the engine, it is possible to effectively cool thegenerator 30. - Further, according to the above configuration, the front and rear
timing transmission units generator 30 are disposed on the left side portion of thecrank case 21 while a startingtransmission unit 94, thefirst transmission unit 54, and the clutch 100 are disposed on the other side of thecrank case 21, so that good balance in weight is maintained between both sides of thecrank case 21 and accordingly, when the internal combustion engine is mounted on thebody frame 1, it is possible to easily offer good balance in weight between the right and left sides of the motorcycle M. - Intake valves 371 and 372 and exhaust valves 381 and 382 are respectively provided in the cylinder heads 231 and 232 of the front and
rear banks valley 28 side between the front andrear banks cam shafts crank shaft 15 are supported by the cylinder heads 231 and 232 viaball bearings 50 and 50', respectively. Thecam shaft 411 is adapted to open/close the intake valve 371 and the exhaust valve 381 viarocker arms 391 and 401, respectively, and thecam shaft 412 is adapted to open/close the intake valve 372 and the exhaust valve 382 viarocker arms 392 and 402, respectively. Timing chains 441 and 442 are wound around thedrive timing sprockets crank shaft 15 and driven timing sprockets 431 and 432 fixed to the left ends of thecam shafts rear banks drive timing sprockets common boss 45 press-fitted around a portion, adjacent to the outer end of theleft journal 17, of thecrank shaft 15. - The
drive timing sprockets 421, the timing chain 441 and the driven timing sprocket 431 of thefront bank 41 constitute the fronttiming transmission unit 461 for reducing the rotational speed of thecrank shaft 15 to half and transmitting the reduced rotational speed to the correspondingcam shaft 411. The fronttiming transmission unit 461 is disposed in a front timing transmission chamber 471 formed in a side wall, on thegenerator 30 side, of thefront bank 41. Thedrive timing sprockets 422, the timing chain 442 and the driven timing sprocket 432 of therear bank 42 constitute the reartiming transmission unit 462 for reducing the rotational speed of thecrank shaft 15 to half and transmitting the reduced rotational speed to the correspondingcam shaft 412. The reartiming transmission unit 462 is disposed in a rear timing transmission chamber 472 formed in a side wall, on thegenerator 30 side, of therear bank 42. - The rear
timing transmission unit 462 is disposed outside the fronttiming transmission unit 461 in the axial direction, that is, it is located closer to thegenerator 30 than the fronttiming transmission unit 461 is. - The
crank shaft 15 is rotated counterclockwise as shown by an arrow R in Fig. 4, and accordingly, the rear sides of the timing chains 441 and 442 are loosened. To give specific tensions to the loosened rear sides of the timing chains 441 and 442, arched chain tensioners 481 and 482 swingably supported by thecrank case 21 are brought into slide-contact with the loosened rear sides of the timing chains 441 and 442. Further, known tensioner lifters 491 and 492 for pressing central portions of the chain tensioners 481 and 482 in the longitudinal direction toward the timing chains 441 and 442 at specific loads are mounted on mounting planes formed on rear surfaces of the cylinder blocks 221 and 222 of the front andrear banks bolts 109, respectively. - The crank
case 21 is divided at the central portion in the lateral direction into aright case half 21b and a left case half 21a. Outer races of theball bearings journals crank shaft 15 are lightly press-fitted in inner races of theball bearings drive timing sprockets common boss 45 is press-fitted around thecrank shaft 15 at the position adjacent to the outer side of theleft journal 17 to pass through the inner race of theleft ball bearing 19, an outside diameter d1 of each of thedrive timing sprockets ball bearing 19. As a result, it is possible to easily press-fit thecommon boss 45 of both thedrive timing sprockets crank shaft 15 as a single part. Further, since theball bearings journals ball bearings - The exit of an exhaust port 511 of the
front bank 41 is opened to the front of the cylinder head 231 of thefront bank 41, and the upstream end of thefront exhaust pipe 131 is connected to the exit of the exhaust port 511. The exit of an exhaust port 512 of therear bank 42 is opened to a right side surface, opposed to the reartiming transmission unit 462, of the rear portion of the cylinder head 232 of therear bank 42, and the upstream end of therear exhaust pipe 132 is connected to the exit of the exhaust port 512. - The front and
rear exhaust pipe chain transmission units rear exhaust pipe exhaust muffler 14 disposed on the right side of therear wheel 2. - With this configuration, since the front and rear
timing transmission units rear bank 42 is offset from thefront bank 41, of the internal combustion engine E, and the front andrear exhaust pipes exhaust pipes timing transmission units exhaust pipes - Further, according to the above configuration, since the
rear exhaust pipe 132 disposed on the right side of the motorcycle M is connected to the exhaust port 512 opened to the right side surface of the rear portion of the cylinder head 232 of therear bank 42, the degree of bending of therear exhaust pipe 132 is reduced, so that it is possible to make small the flow resistance of the pipe and hence to improve the output performance. - A
mission case portion 95 protruded from a lower portion of therear bank 42 is formed integrally with thecrank case 21. Aninput shaft 96 and anoutput shaft 97 of thetransmission 8, which are provided directly behind thecrank shaft 15 in such a manner as to be located on the front and rear sides in parallel to thecrank shaft 15, are contained in themission case portion 95. Both ends of theinput shaft 96 are supported by right and left walls of themission case portion 95 via a pair ofball bearings 98' and 98, and both ends of theoutput shaft 97 are supported by the right and left walls of themission case portion 95 via a pair ofball bearings 99' and 99. Aninner member 101 of the clutch 100 covered with the right cover 34 connected to the right side surface of thecrank case 21 is spline-connected to the right end portion of theinput portion 96. A first drivengear 54b, which is meshed with thefirst drive gear 54a to constitute thefirst transmission unit 54, is mounted to the inner end of theouter member 102. A plurality (five in the example shown in the figures) of speed change gear trains G1 to G5 are selectively arranged between theinput shaft 96 and theoutput shaft 97. - As shown in Fig. 9, a
left wall 95a, which supports the left end portions of theinput shaft 96 and theoutput shaft 97, of themission case portion 95 is offset rightwardly from thetiming transmission unit 462 of therear bank 42. Accordingly, when the tensioner lifter 492 of thetiming transmission unit 462 of therear bank 42 is mounted on the rear surface of the cylinder block 222 of therear bank 42, it is possible to prevent the tensioner lifter 492 from interfering with themission case portion 95. - In particular, since the
timing transmission unit 462 of therear bank 42 is disposed outwardly, that is, leftwardly from thetiming transmission unit 461 of thefront bank 41, it is possible to minimize the rightward offset of themission case portion 95 from thecrank case 21, and hence to realize the compactness of the internal combustion engine E. - The rear wall of the
mission case portion 95 has a mountinghole 103, and avehicular speed sensor 105 having a detectingportion 105a inserted in themission case portion 95 through the mountinghole 103 is fixed on the rear wall of themission case portion 95 with abolt 110. Thevehicular speed sensor 105 is disposed with the detectingportion 105a facing to the tips of a top driven gear, that is, a drivengear 104 of the top gear train G5. - The top driven
gear 104, which is spline-connected to theoutput shaft 97, serves as a shift gear for working the second-speed gear train G2 by leftward shift thereof. In this embodiment, even when the top drivengear 104 is shifted leftwardly, the outer periphery of the top drivengear 104 is not deviated from the detecting region of thevehicular speed sensor 105. Thevehicular speed sensor 105 creates a signal corresponding to the number of teeth of the top drivengear 104 just crossing the detecting portion of thevehicular speed sensor 105 and outputs the signal to a computer (not shown) . The computer calculates a vehicular speed on the basis of the signal thus inputted from thevehicular speed sensor 105 and displays the vehicular speed on a speed meter (not shown) on an instrument panel (not shown) of the motorcycle M. - In this way, the
vehicular speed sensor 105 for detecting the rotational speed of the top drivengear 104 usually rotated together with theoutput shaft 97 can be mounted on the rear wall of themission case portion 95 without any interference with not only therear bank 42 tilted rearwardly toward themission case portion 95 side but also therear exhaust pipe 132 mounted on the rear portion of therear bank 42. - A
rib 106 for covering the lower surface of thevehicular speed sensor 105 is integrally formed on the rear surface of themission case portion 95. The central portion of therib 106 has a through-hole 107 allowing alead wire 108 of thevehicular speed sensor 105 to pass therethrough. - As shown in Fig. 2, a pair of right and left hangers 1121 and a pair of right and left hangers 1122 are integrally formed on the upper and lower sides of the rear surface of the
mission case portion 95 in such a manner as to project therefrom, and a pair of right and left hangers 1123 are integrally formed on the front surface of thecrank case 21 in such a manner as to project therefrom. When the internal combustion engine E is mounted on thebody frame 1, these hangers 1121, 1122, and 1123 are connected to thebody frame 1. Then, thevehicular speed sensor 105 is disposed in a rear dead space of the interior of themission case portion 95 surrounded by the rear side two pairs of the hangers 1121 and 1122. With this configuration, it is possible to enhance the space efficiency. - The
above rib 106 functions to protect thevehicular speed sensor 105 from being affected by small stones and sands flying from a road during running of the motorcycle M. The through-hole 107 for allowing thelead wire 108 to pass therethrough functions as a port for discharging rainwater and cleaning water permeated in therib 106. - As shown in Figs. 2, 3 and 5, the
first drive gear 54a key-connected to the right end portion of thecrank shaft 15 is meshed at its two different portions in the peripheral direction with apump drive gear 56 and the first drivengear 54b. - The
pump drive gear 56 is key-connected to apump shaft 61 which is supported via abearing 86 by the right cover 34 connected to the right end surface of thecrank case 21. Thepump shaft 61, which is in parallel to thecrank shaft 15, is disposed in front of and over thecrank shaft 15. - An
inner rotor 58 of a trochoidtype oil pump 57 for lubrication is fixed on the inner end of thepump shaft 61, and animpeller 63 of awater pump 62 for cooling is fixed on the outer end of thepump shaft 61. Apump housing 60 for containing an outer rotor 59 of theoil pump 57 is screwed in apartition wall 65 for supporting theball bearing 20 of thecrank case 21. Apump casing 64 for containing theimpeller 63 is fixed on the outer surface of the right cover with abolt 87. In this way, theoil pump 57 and thewater pump 62 are coaxially disposed in front of and over thecrank shaft 15. Theoil pump 57 is provided on thecrank case 21 in such a manner as to be adjacent to the outer side of the over-running clutch 53 in the radial direction. - A suction port of the
oil pump 57 is connected via asuction pipe 68 to a strainer 67 (see Fig. 2) disposed in anoil sump 66 on the inner bottom of thecrank case 21, and a discharge port of theoil pump 57 is communicated via anoil passage 69 to thecrank shaft 15, thecam shafts rear banks - An
oil filter 70 positioned substantially directly over thecrank shaft 15 is interposed in the course of theoil passage 69. Theoil filter 70 is mounted to afilter chamber 71 formed in the right cover 34, and acap 72 for closing an opening of thechamber 71 is fixed to the right cover 34. Aninlet chamber 71a on the outer peripheral side of theoil filter 70 in thefilter chamber 71 is communicated to the discharge port of theoil pump 57 via anupstream portion 69a of theoil passage 69 formed in thecrank case 21, and anoutlet chamber 71b on the inner peripheral side of theoil filter 70 in thefilter chamber 71 is communicated to twobranch oil passages cap 72, of theoil passage 69. Onebranch oil passage 69b is communicated to aportion 73 to be lubricated of thecrank shaft 15 system. The otherbranch oil passage 69c is further branched at a connection surface between thecrank case 21 and the right cover 34 into front and rearbranch oil passages cam shafts rear banks - When the
oil pump 57 is driven by the rotation of thecrank shaft 15 via thepump drive gear 56 and thepump shaft 61, oil accumulated in theoil sump 66 is sucked from thestrainer 67 and is press-fed to thefilter chamber 71. The oil is filtered in theoil filter 70 and is then supplied to theportion 73 to be lubricated of thecrank shaft 15 system and the portions 741 and 742 to be lubricated of the valve systems of the front andrear banks portions 73, 741 and 742. Further, with the above-described arrangement and configuration of theoil pump 57, thefilter chamber 71, theoil filter 70 and theoil passage 69, it is possible to make the length of theoil passage 69 as short as possible, and also to arrange the lubricating systems for the front andrear banks banks - The
oil filter 70 is provided with arelief valve 70b for short-circuiting theinlet chamber 71a to theoutlet chamber 71b when afilter element 70a of theoil filter 70 becomes blocked. - In the
water pump 62, as shown in Fig. 6, asuction pipe 75 is connected to an outlet of the radiator 29 (disposed in front of the internal combustion engine E as shown in Fig. 1) via awater pipe 771, and adischarge pipe 76 is connected to a lower portion of the water jacket 241 of thefront bank 41 via awater pipe 772. - As described above, the front and
rear banks chamber 80 opened to the front surface of the cylinder head 232 of therear bank 42 is formed in the cylinder head 232 and an upper portion of the water jacket 242 is communicated to the combinedchamber 80. - Lower joints 781 and 782 communicated to lower portions of the corresponding water jackets 241 and 242 are integrally formed on the opposed surfaces of the front and
rear banks communication water pipe 773 disposed in thevalley portion 28 are connected to these joints 781 and 782. - An upper joint 791 communicated to an upper portion of the jacket 231 is integrally formed on the rear surface of the
front bank 41, and a flange of an upper joint 792 communicated to the combinedchamber 80 is screwed in a lower surface portion of the cylinder head 232 of therear bank 42. Both ends of a rearcommunication water pipe 774 disposed in thevalley portion 28 are connected to these upper joints 791 and 792. - A
thermostat 82 is disposed in the combinedchamber 80, and athermostat cover 81 for holding thethermostat 82 and covering the opening of the combinedchamber 80 is connected to the front surface of the cylinder head 232. - An outlet joint 83 connected to the outlet of the
thermostat 82 is integrally formed on thethermostat cover 81. The outlet joint 83 is connected to the inlet of theradiator 29 via awater pipe 775. - A bypass outlet joint 84 communicated to the combined
chamber 80 via a communication passage 84' is integrally formed on the upper joint 792. The bypass outlet joint 84 is communicated to a heating chamber of thecarburetor 122 of therear bank 42, a heating chamber of thecarburetor 121 of thefront bank 41, and thesuction pipe 75 in sequence by way of a bypass water pipe 85. The bypass outlet joint 84 has an inside diameter sufficiently smaller than that of the outlet joint 83 of thethermostat cover 81. - When the temperature of water in the combined
chamber 80 becomes equal to or less than a specific temperature, thethermostat 82 blocks the combinedchamber 80 from thethermostat cover 81 and opens the communication passage 84' between the combinedchamber 80 and the bypass outlet joint 84. On the other hand, when the temperature of water in the combinedchamber 80 becomes more than the specific temperature, thethermostat 82 communicates the combinedchamber 80 to thethermostat cover 81 and closes the communication passage 84'. - As described, when the
water pump 62 is driven by the rotation of thecrank shaft 15 via thepump drive gear 56 and thepump shaft 61, if the temperature of water in the combinedchamber 80 is relatively low, thethermostat 82 blocks the combinedchamber 80 from thethermostat cover 81 and opens the communication passage 84'. Consequently, cooling water is fed first from thedischarge pipe 76 to the water jacket 241 of thefront bank 41 by thewater pump 62. Here, about a half of the cooling water is immediately fed to the water jacket 242 of therear bank 42 by way of the lowercommunication water pipe 773, and the remaining cooling water passes through the water jacket 241 of thefront bank 41 and is then fed to the combinedchamber 80 of therear bank 42 by way of the uppercommunication water pipe 774. In the combinedchamber 80, the cooling water is combined with the above cooling water having passed through the water jacket 242 of therear bank 42. The cooling water thus combined is fed from the combinedchamber 80 to the bypass outlet joint 84 by way of the communication passage 84', being further fed from the bypass outlet joint 84 to the heating chambers of thecarburetors front banks suction pipe 75 of thewater pump 62. Thereafter, the same circulation is repeated. Such circulation of cooling water not by way of theradiator 29 makes it possible to promote the warming of the internal combustion engine E, and to heat thecarburetors - With advance of the warming of the internal combustion engine E, the temperature of the cooling water whose components having passed through the water jackets 241 and 242 of the front and
rear banks chamber 80 becomes the above specific temperature. At this time, since thethermostat 82 communicates the combinedchamber 80 to thethermostat cover 81 and closes the communication passage 84', the above cooling water flows on the outlet joint 83 side, and is returned to thesuction pipe 75 of thewater pump 62 by way of theradiator 29. Thereafter, the same circulation is repeated. Accordingly, the front andrear banks radiator 29. - Since the lower and upper
communication water pipes valley portion 28 between both thebanks banks water pipes - Since the
thermostat 82 is disposed in the combinedchamber 80 in which components of cooling water having cooled the front andrear banks banks banks thermostat 82, thereby simplifying the entire piping layout. - Since the
thermostat cover 81 including the outlet joint 83 projecting forwardly is connected to the front surface of the upper portion of therear bank 42, it is possible to reduce the degree of bending of thewater pipe 775 for communicating the outlet joint 83 to the inlet of theradiator 29, and hence to make small the flow resistance of thewater pipe 775 and also improve the entire appearance of the internal combustion engine E. - Since the bypass outlet joint 84 having the inside diameter smaller than that of the upper joint 792 of the
rear bank 42 and being communicated to the combinedchamber 80 is integrally formed on the upper joint 792, it is possible to collectively mount the upper joint 792 and the bypass outlet joint 84 to therear bank 42, and hence to simplify the piping works. - Since the
oil pump 57 and thewater pump 62 are coaxially disposed and are driven by thecommon pump shaft 61 driven by thefirst drive gear 54a, it is possible to simplify the drive system thereof. - Since the
oil pump 57 is disposed adjacent to the over-running clutch 53 in the radial direction, it is possible to suppress the increase in lateral width of the internal combustion engine E, although theoil pump 57 and thewater pump 62 are coaxially disposed. - Since the
oil pump 57 and thewater pump 62 are disposed in front of and over thecrank shaft 15, it is possible to compactly form the rear portion of thecrank case 21 and themission case portion 95 continuous thereto without any interference with theoil pump 57 and thewater pump 62, and hence to ensure a desirable ground clearance of the internal combustion engine E and easily reduce the heights of the driver'sseat 6a and thepillion seat 6b. In this case, although the front portion of thecrank case 21 is slightly swelled by the effect of the above arrangement of theoil pump 57 and thewater pump 62, the swelled portion of thecrank case 21 is contained in the lower dead space of thefront bank 41, and therefore, it does not obstruct the compactness of the internal combustion engine E. - Since the drive system of both the
pumps crank shaft 15 is not required to be dipped in oil accumulated in theoil sump 66, it is possible to eliminate the agitation of oil by the drive system and hence to reduce the power loss. - Since the
input shaft 96 and theoutput shaft 97 of thetransmission 8 are horizontally disposed directly after thecrank shaft 15 without any interference with theoil pump 57 and thewater pump 62, it is possible to achieve the compactness of themission case portion 95 and also flatten the upper wall of themission case portion 95. This makes it possible to sufficiently ensure the distance between themission case portion 95 and therear exhaust pipe 132 and hence to easily prevent themission case portion 95 and thetransmission 8 contained therein from being thermally affected by therear exhaust pipe 132. - A containing recessed
portion 88 is formed in the bottom surface of the front portion of thecrank case 21, and the startingmotor 11 is disposed in the containing recessedportion 88 with its axial line directed in parallel to thecrank shaft 15. Acasing 89 of the startingmotor 11 is mounted on thecrank case 21 in such a manner that a cylindrical supportingportion 89a at one end of thecasing 89 is liquid-tightly fitted in a through-hole 90 formed in the end wall of the containing recessedportion 88 and a mountingarm portion 89b at the other end of thecasing 89 is fastened to the crankcase 21 with abolt 111. The leading end of arotor shaft 91 of the startingmotor 11 is inserted in thecrank case 21, and apinion 92 formed on the leading end of therotor shaft 91 is adapted to drive the startinggear 52 via areduction gear train 93. The startinggear 52, the over-runningclutch 53, and thereduction gear train 93 constitute a startingtransmission unit 94 for transmitting the rotational power of the startingmotor 11 to thecrank shaft 15. - As described above, since the starting
motor 11 is disposed in front of and under thecrank shaft 15, the startingmotor 11 also does not obstruct the compactness of the rear portion of thecrank case 21 and themission case portion 95, and since the startingmotor 11 is contained in the lower dead space of thefront bank 41, it does not obstruct the compactness of the internal combustion engine E. Further, thereduction gear train 93 is dipped in oil accumulated in theoil sump 66 on the bottom of thecrank case 21 by the effect of the above arrangement of the startingmotor 11; however, since thereduction gear train 93 is activated not during operation of the engine but upon start-up of the engine, it does not agitate the oil during operation of the engine and thereby does not cause the power loss. - The present invention is not limited to the above embodiments, and it is to be understood that various changes in design may be made without departing from the scope of the present invention.
- Object: To provide a V-type internal combustion engine for a vehicle, which is capable of connecting a primary transmission unit, a starting transmission unit, first and second timing transmission units, and a generator to a crank shaft in a reasonable layout, thereby improving the assembling characteristic and the maintenance characteristic and maintaining a good balance in weight between right and left sides of a vehicular body when the engine is mounted on the vehicle.
- Solving Means: First and second
timing transmission units generator 30 adjacent to the outer side of the first and secondtiming transmission units first journal 17, of acrank shaft 15, and aprimary transmission unit 54 and a startingtransmission unit 94 are connected to the other end, projecting outwardly from asecond journal 18, of thecrank shaft 15.
Claims (3)
- A V-type internal combustion engine for a vehicle, in which first and second journals (17, 18) disposed on a crank shaft (15) with a crank portion (16) held therebetween are supported by a crank case (21) via bearings (19, 20) respectively; a front bank (41) and a rear bank (42) disposed in such a manner as to cross each other in a V-shape centered at said crank shaft (15) are sequentially mounted in said crank case (21); a primary transmission unit (54) for transmitting a power from said crank shaft (15) to a clutch (100), a starting transmission unit (94) for transmitting a drive force of a starting motor (11) to said crank shaft (15), first and second timing transmission units (461, 462) for driving valve system cam shafts (411, 412) of said first and second banks (41, 42) respectively, and a generator (30) are connected to said crank shaft (15); and said crank shaft (15) is disposed laterally in a state that the crank shaft (15) is mounted on said vehicle,
characterized in thatsaid first and second timing transmission units (461, 462) adjacent to each other in the axial direction, and said generator (30) adjacent to the outer side of said first and second timing transmission units (461, 462) are connected to one end portion, projecting outwardly from said first journal (17), of said crank shaft (15), and said primary transmission unit (54) and said starting transmission unit (94) are connected to the other end, projecting outwardly from said second journal (18), of said crank shaft (15). - A V-type internal combustion engine for a vehicle according to claim 1, wherein said crank case (21) is composed of first and second case halves (21a, 21b) divided along a plane perpendicular to the axial line of said crank shaft (15); said first and second journals (17, 18) of said crank shaft (15) are fitted to said first and second case halves (21a, 21b) via ball bearings (19, 20) respectively; and an outside diameter (d1) of each of drive timing sprockets (421, 422) of said first and second timing transmission units (461, 462) fixed on the one end portion of said crank shaft (15) is set to be smaller than an inside diameter (d2) of said ball bearing (19) in which said first journal (17) is fitted.
- A V-type internal combustion engine for a vehicle according to claim 1 or 2, wherein said primary transmission unit (54) is offset on the axial end side more than said starting transmission unit (94); a pump drive gear (56) meshing with a drive gear (54a) of said primary transmission unit (54) is fixed at an intermediate portion of a pump shaft (61) which is supported on said crank case (21) in such a manner as to be in parallel to said crank shaft (15); and a lubricating oil pump (57) disposed in parallel to an over-running clutch (53) of said starting transmission unit (94) is connected to one end of said pump shaft (61) and a cooling water pump (62) is connected to the other end of said pump shaft (61).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP26069598 | 1998-09-14 | ||
JP26069598A JP4021069B2 (en) | 1998-09-14 | 1998-09-14 | V-type internal combustion engine for vehicles |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0987414A2 true EP0987414A2 (en) | 2000-03-22 |
EP0987414A3 EP0987414A3 (en) | 2000-12-13 |
EP0987414B1 EP0987414B1 (en) | 2003-08-06 |
Family
ID=17351500
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19990116978 Expired - Lifetime EP0987414B1 (en) | 1998-09-14 | 1999-08-27 | V-type internal combustion engine for vehicle |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0987414B1 (en) |
JP (1) | JP4021069B2 (en) |
CN (1) | CN1113159C (en) |
DE (1) | DE69910136T2 (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4767603B2 (en) * | 2005-07-04 | 2011-09-07 | ヤマハ発動機株式会社 | Power unit and straddle-type vehicle equipped with the power unit |
CN102062183B (en) * | 2009-11-13 | 2013-06-12 | 中国第一汽车集团公司 | Method for performing timing assembly on V-shaped engine chain system |
CN102146839A (en) * | 2011-04-01 | 2011-08-10 | 湖南华强电气有限公司 | Method for driving auxiliary power generator by using automotive engine and automotive engine |
JP6152071B2 (en) * | 2014-04-25 | 2017-06-21 | 本田技研工業株式会社 | Continuously variable transmission |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6483912A (en) | 1987-09-24 | 1989-03-29 | Yamaha Motor Co Ltd | Connecting portion structure between crank shaft and connecting rod |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4589382A (en) * | 1982-01-08 | 1986-05-20 | Honda Giken Kogyo Kabushiki Kaisha | V-type multicylinder internal combustion engine |
JPS58119929A (en) * | 1982-01-08 | 1983-07-16 | Honda Motor Co Ltd | V-shaped multi-cylinder internal-combustion engine |
US4903483A (en) * | 1988-02-17 | 1990-02-27 | Yamaha Hatsudoki Kabushiki Kaisha | Exhaust system for V-type engine |
US4960081A (en) * | 1988-12-16 | 1990-10-02 | Yamaha Hatsudoki Kabushiki Kaisha | Belt driven camshaft mechanism for internal combustion engine |
-
1998
- 1998-09-14 JP JP26069598A patent/JP4021069B2/en not_active Expired - Fee Related
-
1999
- 1999-08-27 EP EP19990116978 patent/EP0987414B1/en not_active Expired - Lifetime
- 1999-08-27 DE DE69910136T patent/DE69910136T2/en not_active Expired - Lifetime
- 1999-09-09 CN CN99118579A patent/CN1113159C/en not_active Expired - Fee Related
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6483912A (en) | 1987-09-24 | 1989-03-29 | Yamaha Motor Co Ltd | Connecting portion structure between crank shaft and connecting rod |
Also Published As
Publication number | Publication date |
---|---|
DE69910136D1 (en) | 2003-09-11 |
EP0987414A3 (en) | 2000-12-13 |
JP2000087756A (en) | 2000-03-28 |
CN1113159C (en) | 2003-07-02 |
JP4021069B2 (en) | 2007-12-12 |
CN1247936A (en) | 2000-03-22 |
DE69910136T2 (en) | 2004-06-09 |
EP0987414B1 (en) | 2003-08-06 |
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