JPH0825980A - Power unit for vehicle - Google Patents

Abstract

PURPOSE:To provide a power unit allowing vehicular power unit made of an internal combustion engine integrated with a reduction gear to be easily installed on a vehicle. CONSTITUTION:An engagement notch 73 directed to the center and upper side of a case and having a front end 73a directed upward, is formed on the left upper sections of a front crank case 3 and a rear crank case 4. Thereafter, a support jig 80 with a coupling projection 81 and a lower hole 82 formed at a gap agreeing to a gap between the end 73a of the notch 73 and a mounting boss 81 is used to engage the projection 81 with the notch 73. After the jig 80 is thereby coupled to the end 75a of the notch 73, a pin is inserted in the hole 82 of the jig 80 and the mounting boss 81.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power unit mounted on a vehicle such as a three-wheeled vehicle or a four-wheeled vehicle, and in particular, an internal combustion engine and a transmission which are suitable for a saddle type vehicle for running on rough terrain called a buggy vehicle are integrated. The present invention relates to a vehicle power unit.

[0002]

2. Description of the Related Art Most of the conventional saddle riding type vehicles 01 are shown in FIG.
(See Japanese Patent Laid-Open No. 63-137087),
The power unit 02 was mounted with the crankshaft and the transmission shaft oriented in the vehicle width direction at right angles to the traveling direction of the vehicle.

[0003]

[Problems to be solved] Power unit shown in FIG.
In 02, mounting bosses 04, 05, 06, 07 are formed in the front upper part, front upper and lower intermediate parts, rear upper part, and lower part of a case 03 in which a crank case and a transmission case are integrated, and the mounting bosses 04, 05, 06, 07 are formed. Since 05, 06, and 07 are detachably attached to the body frame 08 via the bracket 09, the power unit 02 is attached to the body frame 08 of the saddle type vehicle 01.
When assembling the power unit 02, a jig (not shown) was inserted into the hole of the mounting boss 06 and the tip claw of the hanging metal fitting (not shown) was engaged with the front lower end step 011 of the cylinder head 010 to lift the power unit 02.

Normally, a saddle-type vehicle 01 includes a power unit.
Since the body frame 08 also exists above 02, the power unit 02 hung by the jig and the hanging metal fitting cannot be lowered from above and assembled to the body frame 08. The power unit 02 must be loaded in the power unit 02 by moving it in the vehicle width direction while supporting the power unit 02 in a cantilevered manner with the two kinds of jigs and suspension fittings being oriented in the vehicle width direction. The assembly work of 02 was not easy.

Further, when assembling the power unit in which the crankshaft and the transmission shaft are oriented in the traveling direction of the vehicle to the saddle-riding vehicle, the tip portions of the jig and the hanging metal fitting are bent at a right angle, and the tip bent portion is bent. Since it must be moved in the vehicle direction while moving in the vehicle traveling direction to engage with the mounting boss to be supported in a cantilever manner, the crankshaft and the transmission shaft are laterally mounted saddle-riding vehicles at right angles to the vehicle traveling direction. It was more difficult to assemble than 01.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an improvement of a vehicle power unit that overcomes the above problems, and a crank case of an internal combustion engine and a transmission case are integrated and rotated in the case. In a power unit for a vehicle in which a crank shaft and a transmission shaft group that are freely rotatably supported are oriented in the vehicle traveling direction and mounted in a substantially central portion of the vehicle, mounting bosses are provided on both lower sides of the case so as to project therefrom. It is characterized in that an engaging notch is formed on one side of the upper part from the side of the case toward the center of the case, and the tip portion is directed upward of the case.

Since the present invention is constructed as described above, after engaging the engaging projection of the supporting jig with the engaging notch of the vehicle power unit, the lower portion of the supporting jig is located below the engaging projection. The vehicle power unit is integrally coupled with the mounting boss, the vehicle power unit is supported in a cantilever manner by the support jig, and the vehicle power unit is loaded into the vehicle body from the side of the vehicle. The power unit can be installed in a vehicle easily.

Further, in the present invention, since it suffices to provide the mounting boss on both sides of the lower part of the case, when the power unit of the present invention is mounted on a saddle type vehicle, the mounting boss protruding from the upper part of the power unit is used. The power unit will not approach the inner thighs of the driver sitting on the saddle type vehicle.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention shown in FIGS. 1 to 14 will be described below.

In a saddle riding type vehicle A for running on rough terrain called a buggy vehicle shown in FIG. 1, a channel-shaped main frame B ₁ is installed in a pair of left and right and is erected in the front-rear direction above the vehicle body. main pipe-shaped frame B ₂ under the frame B ₁ is provided integrally, mounting a pair of left and right balloon-type low-pressure tires, respectively front and rear of the body frame B consisting of these channel-shaped main frame B ₁ and the pipe-shaped frame B ₂ The front wheel Wf and the rear wheel Wr are suspended.

Further, in the upper part of the saddle riding type vehicle A for traveling on rough terrain,
A steering handle H, a fuel tank T, and a seat S are sequentially arranged from the front to the rear, and a front wheel Wf and a rear wheel Wr are provided at the center of the body frame B below the fuel tank T and the seat S. A power unit P for driving is mounted.

Further, in the saddle riding type vehicle A for traveling on rough terrain, a fender F covering substantially the upper portions of the front wheels Wf and the rear wheels Wr, respectively.
And a carrier C located on the upper surface thereof.

Further, a step D for supporting both feet of a driver sitting on the seat S is arranged in the lower center of the body frame B, and a brake pedal (not shown) is arranged near the right step D. In addition, a change pedal (not shown) is arranged near the left step D.

Furthermore, the power unit P is constructed by integrating a crankcase of the internal combustion engine E and a transmission case of the transmission M, and the internal combustion engine E includes a cylinder head 1, a cylinder block 2, a front crankcase 3. Rear crankcase 4, front case cover 5, and rear case cover 6
The front crankcase 3 and the rear crankcase 4, which are divided into two parts and are integrated with each other by connecting bolts (not shown), are attached to the mounting bosses 8 on both lower sides thereof as shown in FIGS. 2 and 3. Further, it is adapted to be coupled to the left and right pipe-shaped frames B ₂ via the elastic mount members 9.

Moreover, as shown in FIGS. 6 to 9, the cylinder block 2 is superposed on the front crankcase 3 and the rear crankcase 4 which are integrally connected to each other, and the cylinder block 2 and the front crankcase 3, A cylinder / case coupling bolt 11 is fitted and screwed into two bolt holes 10 provided in the rear crankcase 4, and the cylinder head 1 and the rocker arm holder 19 are superposed on the cylinder block 2. The holder / head / cylinder coupling bolt 13 is fitted and screwed into one bolt hole 12 provided in the rocker arm holder 19, the cylinder head 1, and the cylinder block 2, and the cylinder head 1 is also tightened. The head / cylinder coupling bolt 15 is inserted into one bolt hole 14 provided in the cylinder block 2 and screwed and tightened. And two bolts 16 provided on the cylinder head 1, the cylinder block 2, the front crankcase 3 and the rear crankcase 4.
The head / cylinder / case coupling bolt 17 is fitted and screwed and tightened to the rocker arm holder 19,
A coupling bolt (not shown) is fitted and screwed into bolt holes 18 provided in the cylinder head 1, the cylinder block 2, the front crankcase 3 and the rear crankcase 4, and the cylinder head 1, cylinder block 2, front crankcase 3, rear crankcase 4
The rocker arm holder 19 and the rocker arm holder 19 are integrally connected.

Further, the crankshaft 20 rotatably supported by the front crankcase 3 and the rear crankcase 4 of the internal combustion engine E in the traveling direction of the saddle riding type vehicle A for traveling on rough terrain is
As shown in FIG. 5, the cylinder block 2 is arranged so as to be slightly deviated to the right from the center of the front crankcase 3 and the rear crankcase 4 so as to be directed obliquely to the upper left from the crankshaft 20. And the piston 22 in which the cylinder head 1 is tilted to the left and is slidably fitted in the cylinder 21.
Is connected to a crank pin 23 of the crankshaft 20 via a connecting rod 24, and the crankshaft 20 is rotationally driven by raising and lowering the piston 22.

Further, a main shaft 25 and a sub shaft 26 of the transmission M are sequentially arranged on the left side of the crank shaft 20, and a reverse shaft 27 is arranged above and above the main shaft 25 and the sub shaft 26.
With the drive shaft 28 arranged below the main shaft 25 and the auxiliary shaft 2
The reverse shaft 27 and the drive shaft 28 are rotatably supported by the front crankcase 3 and the rear crankcase 4 in parallel with the crankshaft 20.

Further, a cam shaft 29 is provided on the upper right of the crank shaft 20.
Is arranged, the balancer shaft 30 is arranged below it, and the shift drum 31 is arranged below the main shaft 25 to the right of the drive shaft 28, and the cam shaft 29, the balancer shaft 30, The shift drum 31 is rotatably supported by the front crankcase 3 and the rear crankcase 4.

Furthermore, as shown in FIG. 4, the crankshaft 20 and the camshaft 29 are provided with sprockets 32 and 33, respectively, and an endless chain 34 is bridged over the sprockets 32 and 33. When the 20 rotates, the cam shaft 29 moves to 1
It is designed to be rotated at a rotation speed of / 2.

Since the sprockets 32, 33 are arranged at positions projecting forward from the front crankcase 3, the chain tensioner 36 swings up and down on the bearing holder 35 of the main shaft 25, as shown in FIG. FIG. 12 shows a pressing part of an adjusting device 38 which is rotatably supported, has a slipper 37 provided on the lower surface of the tip of the bearing holder 35, and which is fitted from above the front crankcase 3 and attached by a bolt (not shown). As shown, the chain tensioner 36 is adapted to abut a receiving portion 39 protruding forward from the chain tensioner 36, and the endless chain 34 is moved by the chain tensioner 36 that is urged by the attachment force of the pressure lowering part of the adjusting device 38. The tension is set appropriately.

As shown in FIG. 11, the hydraulic pump 40 is disposed in front of the balancer shaft 30, and the rotary shaft of the hydraulic pump 40 is directly connected to the balancer shaft 30. In the operating state, the hydraulic pump 40 is rotationally driven integrally with the balancer shaft 30, and the lubricating oil is supplied to the lubricated portions of the internal combustion engine E and the transmission M.

As also shown in FIGS. 11 and 13,
An intake cam 41 and an exhaust cam 42 are integrally formed on the cam shaft 29,
A decompression cam 43 is attached adjacent to the front of the exhaust cam 42, and a rib 44 is formed on the rear of the intake cam 41,
Moreover, the front crankcase 3 has the same diameter as the outer peripheral surface of the ball bearing 45 that supports the front portion of the camshaft 29 and the camshaft.
A cylindrical surface portion 46 having a diameter larger than the base circle diameter of 29 and a locking step portion 47 are formed behind the cylindrical surface portion 46, and the intake cam 41, the exhaust cam 42, and the decompression cam 43 have a positional relationship as shown in FIG. In this state, the locking shaft 47 is formed with notches 48 and 49 so that the cam shaft 29 can be pulled out forward.

Further, a tappet 50 is fitted to the front crankcase 3 and the rear crankcase 4 so as to be vertically movable above the intake cam 41 and the exhaust cam 42. As shown in FIG. 5, a rocker arm holder is provided. A push rod 53 is interposed between the tappet 50 and the right end of a rocker arm 52 pivotally supported on a rocker shaft 51 via a rocker shaft 51, and the rocker arm 52 moves up and down in response to the rotation of the cam shaft 29. The intake valve 54 and the exhaust valve 55, which are swung and located to the right of the center of the cylinder 21 and are in contact with the left end of the rocker shaft 51, are opened and closed.

Further, a spark plug 56 is mounted on the left side of the center line of the cylinder 21 and further inclined to the left side of the center line of the cylinder 21.

An intake passage 57 provided with an intake valve 54
A carburetor 59 is connected to, and an exhaust pipe (not shown) is connected to an exhaust passage 58 provided with an exhaust valve 55.

Further, a rotor 60r of the ACG 60 is attached to the rear portion of the crankshaft 20, an ACG cover 7 is detachably attached to a rear case cover 6 attached to the rear crankcase 4, and the ACG 60 is attached to the ACG cover 7. Stator 60s
As shown in FIG. 10, the A
ACG60 and other electrical components are mounted on the CG cover 7. When the ACG cover 7 is removed, the stator 60s of the ACG60, the pulsar 61, and other electrical components are AC at once.
It can be taken out together with the G cover 7.

Furthermore, a starting wheel 62 is provided at the rear end of the crankshaft 20.
Is mounted, and a recoil starter 63 is disposed opposite thereto, and the internal combustion engine E can be started by manually operating the recoil starter 63.

Further, as shown in FIG. 11, a starting gear 65, which is located in front of the rotor 60r of the ACG 60, is loosely fitted to the crankshaft 20 via a one-way clutch 64 and attached to the rear crankcase 4. The output shaft 66a of the starter motor 66 is connected to the starting gear 65 via the reduction gear device 67,
When the starter motor 66 rotates, the crankshaft 20 is rotationally driven via the reduction gear device 67, the starting gear 65, and the one-way clutch 64, and the internal combustion engine E is automatically started.

Further, a centrifugal starting clutch 70 is provided at the front end of the crankshaft 20, and a multi-plate speed change clutch 71 is provided at the front end of the main shaft 25. The output gear 70a of the centrifugal start clutch 70 is a multi-plate speed change clutch 71. When the crankshaft 20 is stopped or is rotating at a predetermined rotation speed or less, the centrifugal starting clutch 70 is in the disengaged state, and when it exceeds the predetermined rotation speed, the centrifugal The centrifugal starting clutch 70 is configured so that the starting clutch 70 is in the connected state.

Still further, as shown in FIG.
A multi-speed transmission gear train 72 is interposed between the auxiliary shaft 26 and the auxiliary shaft 26.
The output gear 26a of is meshed with the input gear 28a of the drive shaft 28,
As shown in FIG. 12, the output gear 25a of the main shaft 25 is meshed with the input gear 27a of the reverse shaft 27, and the output gear 27b of the reverse shaft 27 is the reverse input gear 26 of the counter shaft 26.
When the change pedal, which is meshed with b and is located near the left step D, is operated to the required shift position or reverse position, the multi-plate shift clutch 71 is disengaged and the multi-stage shift gear train 72 and the auxiliary shift gear are operated only when the shift pedal is operated. The reverse input gear 26b of the shaft 26 is switched, and the auxiliary shaft 26 is set to a required gear ratio or a normal / reverse rotation state and driven to rotate.

Further, as shown in FIG. 15, the front crankcase 3 and the rear crankcase 4 are provided at the upper left ends thereof toward the center of the case and toward the upper side of the case, and the tips 73 are provided.
An engagement notch 73 is formed in which a is directed upward.

Further, the case upper surface portion 7 on the left side of the cylinder openings 74 of the front crankcase 3 and the rear crankcase 4
Of the five and 76, the clutch upper portion 77 adjacent to the front of the case upper surface portion 75 rises upward due to the ACG 60 inside thereof, and also the transmission upper portion 7 on the left side of the case upper surface portions 75 and 76.
8 and 79 also rise upward, and the case upper surfaces 75 and 76 surrounded by the clutch upper portion 77 and the transmission upper portions 78 and 79 gently incline downward toward the clutch upper portion 77. Is formed.

Since the embodiment shown in FIGS. 1 to 14 is constructed as described above, the driver sits on the seat S, puts his foot on the step D, and starts the starter motor 66 or the recoil starter 63. With the internal combustion engine E started, the right grip of the steering handle H is gripped and an operating lever (not shown) provided below the steering handle H is operated to open the carburetor 59, When the internal combustion engine E is accelerated and the crankshaft 20 exceeds a predetermined rotation speed, the centrifugal start clutch 70 is automatically connected, and the saddle riding type vehicle A for running on rough ground
Can start running.

Further, since the crankshaft 20, the main shaft 25, the auxiliary shaft 26, the reverse shaft 27, and the drive shaft 28 are all oriented in the traveling direction of the saddle riding type vehicle A for traveling on rough terrain, the bevel gear device is minimized. Therefore, the power of the internal combustion engine E can be supplied to the front wheels Wf and the rear wheels Wf.
It can be transmitted to the front wheel differential gear unit Gf and the rear wheel drive gear unit Gr of r, and the weight of the power transmission system can be reduced.

Further, in the power unit P, the upper portion of the crankshaft 20 is tilted to the left and the lower portion of the crankshaft 20 is arranged slightly offset to the right from the center of the width of the front crankcase 3 and the rear crankcase 4, To the left of the crankshaft 20, a main shaft 25, a sub shaft 26, a reverse shaft 27, and a drive shaft of the transmission M.
28 and the shift drum 31 are arranged, and the cam shaft 29, the balancer shaft 30, the hydraulic pump 40, the starter motor 66, the valve train tappet 50, the rocker shaft 51, the rocker arm 52 and the push rod 53 are arranged on the right side of the crank shaft 20. Therefore, it is possible to reduce the heights of the front crankcase 3 and the rear crankcase 4 while keeping the left and right widths of the front crankcase 3 and the rear crankcase 4 narrow, and to downsize the power unit P. In addition, the front shape of the power unit P is formed into a substantially isosceles triangular shape so that the center of gravity of the power unit P can be lowered, and the driver can easily sit on the seat S above the power unit P without the power unit approaching the inner crotch. be able to.

Further, since the cylinder 21 is tilted to the left, and the spark plug 56 is further tilted to the left by being offset to the left from the center of the cylinder 21, the fuel tank T and the seat S above the cylinder 21 are The spark plug 56 can be easily replaced without being disturbed.

Since the crankshaft 20 is tilted to the left, the camshaft 29 is arranged on the upper right side of the crankshaft 20, and the push rod 53 is arranged on the right side of the cylinder 21,
Compared with a push rod provided above the crankshaft, the dimension of the internal combustion engine E in the crankshaft direction can be shortened, and the front-rear length of the entire power unit P can be shortened.
Moreover, the length of the push rod 53 can be shortened, and the weight of the reciprocating portion of the valve train can be reduced.

Further, since the balancer shaft 30 is located below the cam shaft 29 and the hydraulic pump 40 is arranged on the axis of the balancer shaft 30, the height of the hydraulic pump 40 with respect to the lubricating oil surface O in the power unit P is increased. Therefore, the suction height of the hydraulic pump 40 can be reduced, and the suction of the lubricating oil can be smoothly performed.

Furthermore, the cylinder head 1, the cylinder block 2, the front crankcase 3, and the rear crankcase 4
Since the rocker arm holder 19 and the rocker arm holder 19 are coupled as shown in FIGS. 6 to 9, the cylinder head 1, the cylinder block 2, the front crankcase 3, the rear crankcase 4 and the rocker arm holder 19 are firmly integrated with each other. The cylinder head 1 and the cylinder block 2 can be made by simply tightening the cylinder / case coupling bolt 11, the head / cylinder / case coupling bolt 17 and the bolts (not shown) screwed and tightened into the bolt holes 18.
The rocker arm holder 19 and the rocker arm holder 19 can be easily removed from the front crankcase 3 and the rear crankcase 4 while being connected to each other.

Moreover, when it is attempted to replace the camshaft 29 by removing the cylinder head 1 and the cylinder block 2 from the front crankcase 3 and the rear crankcase 4, as shown in FIG. When the sprocket 33 is removed from the cam shaft 29 by removing the bolt 33a connecting the sprocket 33 and the sprocket 33, the tappet 50 is extracted upward from the front crankcase 3 and the rear crankcase 4, and then the intake cam 41 is removed. Unless the exhaust cam 42 and the decompression cam 43 are aligned with the notch 49 while aligning the position with the notch 48, the intake cam 41
The rib 44 is locked to the tappet 50 that has fallen on the base circle of, or the intake cam 41, the exhaust cam 42, and the decompression cam 43 are locked to the locking step portion 47, so that the cam shaft 29 cannot be pulled out. As a result, the tappet 50 is accidentally dropped into the front crankcase 3 and the rear crankcase 4, and if the front crankcase 3 and the rear crankcase 4 are not disassembled, the tappet 50 inside the front crankcase 3 and the rear crankcase 4 cannot be disassembled. The problem that the tappet 50 cannot be taken out can be prevented in advance.

Further, as shown in FIG. 15, the support jig 80 has a gap between the coupling projection 81 and the lower hole 82 which is matched with the gap between the tip portion 73a of the engaging notch 73 and the mounting boss 8l. Ingredient
Using 80, the coupling projection 81 of the support jig 80 is engaged with the engagement notch 73 and locked to the tip portion 73a thereof, and then the support jig 80
By inserting a pin (not shown) into the hole 82 of the internal combustion engine E and the mounting boss 8l, the supporting jig 80 is attached to the front crankcase 3 of the internal combustion engine E.
It can be integrally connected to the rear crankcase 4, and in that state,
The power unit P can be supported in a cantilever manner by pulling it upward while applying a counterclockwise moment to the support jig 80.

Therefore, even if the vehicle body frame B of the saddle riding type vehicle A for running on rough terrain is formed in a loop shape in a side view and the channel-shaped main frame B ₁ exists above the power unit P, this channel-shaped main frame B ₁ exists. Without being disturbed by the frame B ₁ , the power unit P is loaded into the saddle riding type vehicle A for running from the side of the saddle riding type vehicle A for running on the rough land,
The power unit P can be easily installed on the pipe-shaped frame B ₂ via the mounting boss 8 and the elastic mount member 9.

Further, even if the case upper surface portions 75 and 76 on the left side of the cylinder opening 74 are surrounded by the clutch upper portion 77 and the transmission upper portions 78 and 79 which are raised upward, the case upper surface portion 75 and the case Since the upper surface portion 76 gently inclines downward from the front to the rear, rainwater and the like can be naturally discharged without being collected in the case upper surface portions 75 and 76.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a saddle riding type vehicle for traveling on rough ground, which is equipped with a vehicle power unit of the present invention.

FIG. 2 is an enlarged side view of a main part of FIG.

3 is a view taken along the line III-III in FIG.

FIG. 4 is a front view of the power unit with a front case cover removed.

FIG. 5 is a partially longitudinal rear view in which the rear case cover is removed and the centers of the cylinder head and the cylinder block are cut off.

FIG. 6 is a vertical cross section of the internal combustion engine cut along the line VI-VI in FIG.

FIG. 7 is a plan view of a cylinder head.

FIG. 8 is a plan view of a cylinder block.

FIG. 9 is a plan view of relevant parts of a front crankcase and a rear crankcase.

10 is a vertical cross-sectional view of the power unit cut along the line XX of FIG.

11 is a vertical cross-sectional view of the power unit cut along the line XI-XI of FIG.

12 is a vertical cross-sectional view of the power unit cut along the line XII-XII in FIG.

13 is an enlarged vertical cross-sectional view of a main part of FIG.

FIG. 14 is an XIV-XIV arrow view of FIG. 13.

FIG. 15 is a perspective view of the main parts of 3 and 4 as seen from the upper left rear side.

FIG. 16 is a side view of a conventional vehicle.

[Explanation of symbols]

A ... Saddle-type vehicle for running on rough terrain, B ... Body frame, C ... Carrier, D ... Step, E ... Internal combustion engine, F ... Fender,
Gf ... front wheel differential device, Gr ... rear wheel drive gear device, H ... steering wheel, M ... transmission, O ... lubricating oil surface, P ... power unit, S ... seat, T ... fuel tank, Wf ... front wheel,
Wr ... rear wheel, 1 ... cylinder head, 2 ... cylinder block, 3 ... front crankcase, 4 ... rear crankcase,
5 ... Front case cover, 6 ... Rear case cover, 7 ... ACG
Cover, 8 ... Mounting boss, 9 ... Elastic mount member, 10 ...
Bolt hole, 11 ... Cylinder / Case connecting bolt, 12 ... Bolt hole, 13 ... Holder / Head / Cylinder connecting bolt, 14 ...
Bolt hole, 15 ... Head / cylinder coupling bolt, 16 ... Bolt, 17 ... Head / cylinder / case coupling bolt, 18 ... Bolt hole, 19 ... Rocker arm holder, 20 ... Crank shaft, 21
... Cylinder, 22 ... Piston, 23 ... Crank pin, 24 ... Connecting rod, 25 ... Main shaft, 26 ... Secondary shaft, 27 ... Reverse shaft, 28 ... Drive shaft, 29 ... Cam shaft, 30 ... Balancer shaft, 31 ...
Shift drum, 32, 33 ... sprocket, 34 ... endless chain, 35 ... bearing holder, 36 ... chain tensioner,
37 ... Slippers, 38 ... Adjusting device, 39 ... Receiving part, 40 ... Hydraulic pump, 41 ... Intake cam, 42 ... Exhaust cam, 43 ... Decompression cam, 44 ... Rib, 45 ... Ball bearing, 46 ... Cylindrical surface part, 47 ... Engagement Stops, 48, 49 ... Notches, 50 ... Tappets, 51
... rocker shaft, 52 ... rocker arm, 53 ... push rod, 54 ... intake valve, 55 ... exhaust valve, 56 ... spark plug, 57 ... intake passage, 58 ... exhaust passage, 59 ... carburetor, 60 ... ACG, 61 ... pulsar , 62 ... starting wheel, 63 ... recoil starter, 64 ... one-way clutch, 65 ... starting gear, 66 ... starter motor, 67 ...
Reduction gear device, 68, 69 ... Gears, 70 ... Centrifugal start clutch, 71 ... Multi-plate shift clutch, 72 ... Multi-speed gear train, 73
… Coupling notch, 74… Cylinder opening, 75,76… Case top part, 77… Clutch upper part, 78,79… Transmission upper part, 80…
Support jig, 81 ... Engaging protrusion, 82 ... Hole.

Claims (1)

[Claims] 1. A crankcase of an internal combustion engine and a transmission case are integrated with each other, and a crankshaft and a transmission shaft group rotatably supported by the case are oriented in the traveling direction of the vehicle and are located in a substantially central portion of the vehicle. In a vehicle power unit to be mounted, mounting bosses are provided on both sides of the lower part of the case, and an engaging notch is formed on one side of the upper part of the case from the side of the case toward the center of the case and the tip of which is directed to the upper part of the case. A power unit for a vehicle, which is formed.