JP3315881B2 - Power transmission device for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle power transmission device provided with a starting clutch, a switching clutch, and a gear transmission, and more particularly to a power transmission device for a motorcycle. Not only during operation,
At the time of a shift-up operation for each gear from the first gear to the final gear, a braking force is applied to the output member of the starting clutch,
The present invention relates to a vehicular power transmission device capable of suppressing impulses and noises at the time of a shift operation and easily performing a shift operation.

[0002]

2. Description of the Related Art An internal combustion engine is mounted on a vehicle, and a clutch outer on the output side of a starting clutch is relatively rotatably fitted to a crankshaft of the internal combustion engine. In a conventional vehicle power transmission device in which power is transmitted to wheels via a transmission, the vehicle is stopped and the internal combustion engine is operated, and when the gear transmission is set to a neutral stage, the starting clutch The clutch outer rotates with the rotation of the crankshaft, and the connected shift clutch and the main shaft also rotate correspondingly, but the countershaft connected to the wheels is stopped,
When a shift-up operation is performed from the neutral gear to the first gear, even if the switching clutch is disengaged at the beginning of the operation,
As a result of the rotation of the main shaft and the gears on the main shaft due to its rotational inertia, impact force and noise are generated due to meshing between the rotating gear on the machine shaft and the stop gear on the counter shaft.

In order to eliminate such impact force and noise, a cam is integrally provided on a shift drum of a gear transmission and a clutch outer of a starting clutch as described in Japanese Patent Application Laid-Open No. 2-212675. When the gear is shifted up from the neutral gear to the first gear, the cam makes the brake shoe abut on the clutch outer to stop the clutch outer and shift the gear on the machine shaft. Had to be stopped.

[0004]

However, in the structure disclosed in the above-mentioned publication, the braking force is applied to the clutch outer of the starting clutch only at the time of the shift-up operation from the neutral gear to the first gear. There was a problem that the system became complicated, the number of parts increased, and the cost increased.

In the above-mentioned publication, the spring force of the spring for urging the brake shoe toward the clutch outer changes between the first speed and the other speeds, so that the shift operation force changes. There was a problem that the operation feeling of the shift operation was different.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an improvement in a vehicular power transmission device in which such a problem is solved, and in which an output member of a starting clutch is relatively connected to a crankshaft of an internal combustion engine mounted on the vehicle. A power transmission device for a vehicle, in which power is transmitted to wheels via the starting clutch, the switching clutch, and the gear transmission from the crankshaft, the final transmission being shifted from a neutral stage of the gear transmission. A speed change braking member for applying a braking force to the large diameter portion of the output member of the starting clutch is provided only during each speed change up operation of the speed change operation mechanism for changing the speed ratio up to the first gear. Is directly coupled to a clutch operating member of the switching clutch, and performs braking in conjunction with a shift-up operation of each stage of the switching clutch. It is intended.

According to the present invention, as described above, a special cam for braking a starting clutch output member, and a brake shoe linked to the starting clutch are provided on the shift drum of the gear transmission. interlocking mechanism for selectively contact becomes unnecessary, the structure is simplified, the number of parts is reduced, the cost can be reduced.

Further, in the present invention, since the braking force is applied to the output member of the starting clutch regardless of the shift speed to which the gear is shifted up, there is a difference in the shift-up operation force for each shift speed. And the feeling of upshift operation is improved.

Further, conventionally, in order to make the peripheral speed of the input side gear of the gear transmission coincide with the peripheral speed of the output side gear during the upshifting operation, the throttle is throttled during the upshifting operation and the crankshaft is rotated. By reducing the speed, the input side gear of the gear transmission is decelerated, but in the present invention, the braking force is applied to the large diameter portion of the output member of the starting clutch which is in the clutch connected state to the crankshaft. In addition, since the input side gear of the gear transmission can be surely decelerated, the meshing between the input and output side gears of the gear transmission is smoothly performed even when the throttle aperture operation amount is small, and the speed change operation during the speed change operation is performed. Shock and noise are further reduced. Furthermore, when a downshift operation is to be performed to reduce the vehicle speed, the rotation speed of the internal combustion engine decreases due to a decrease in the throttle opening, without applying a braking force to the output member of the starting clutch. The countershafts and the counter gear group rotating in the high-speed running state before the downshift operation maintain the high-speed rotation state due to its rotational inertia. Even when down,
The generation of shock and noise during the gear shifting operation is suppressed. Moreover,
Since the shift switching braking member is directly coupled to the clutch operating member of the switching clutch, the shift operating force of the clutch operating member of the switching clutch is reliably transmitted to the shift switching braking member, and The switching operation is performed smoothly.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle power transmission device according to the present invention will be described below. The overhead-valve single-cylinder internal combustion engine 1 equipped with the vehicle power transmission device of the present invention is a spark ignition type four-stroke cycle internal combustion engine, in which a motorcycle (not shown) includes a cylinder block 3 and a cylinder head 4 which are substantially horizontal. It is mounted in a state oriented in the direction,
As shown in FIG. 1, the overhead valve type single cylinder internal combustion engine 1
The cylinder block 3, the cylinder head 4, and the head cover 5 are sequentially stacked in front of the left and right split crankcases 2, and are integrally joined by joining means such as bolts (not shown). The left crankcase cover 6 and the right crankcase cover 7 are integrally connected with bolts (not shown).

As shown in FIG. 3 , a piston 9 is slidably fitted back and forth in a cylinder hole 8 formed in the cylinder block 3, and a crankshaft 10 is 11 is rotatably pivoted through 11 and the crankpin 12 of the crankshaft 10
The connecting rod 14 is rotatably fitted to the piston pin 13 of the piston 9 and the piston pin 13 of the piston 9.
The crankshaft 10 is driven to rotate in accordance with the reciprocation of the crankshaft.

Further, the variable venturi carburetor 15 shown in FIG. 1 is inserted into the cylinder hole 8 through an intake port (not shown) .
In the variable venturi carburetor 15, a venturi piston (not shown) also serving as a throttle valve is connected to a throttle grip (not shown) via a throttle wire 16 and is operated by operating the throttle grip. , venturi piston is up and down, the intake air amount, in other words, the amount of fuel supply adjustment
It is supposed to be.

Further , as shown in FIG. 3, a drive sprocket 17 of a valve train is fitted on the left side of the crankshaft 10 and is connected to a starter motor (not shown). A sprocket 18 and a generator 19 are provided.

As shown in FIG. 4, a clutch outer 21 of the starting clutch 20 is relatively rotatably fitted to the right side of the crankshaft 10, and a clutch inner 22 of the starting clutch 20 is The clutch inner 22 is attached to the right end of the
The base ends of the clutch weights 23 are pivotally pivoted along the rotation surface of the clutch inner 22 by pins 28 , and FIG.
As shown in FIG. 3 , a return spring 25 is stretched between a base end of the clutch weight 23 and a tip end of the clutch weight 23 adjacent to the clutch weight 23. Spring 25
The tip of the clutch weight 23 is pulled in the direction of the crankshaft 10 by the tension spring force of
When the clutch shoe 24 moves away from the inner peripheral surface of the clutch outer 21 and the starting clutch 20 is disengaged, and the crankshaft 10 rotates beyond a predetermined number of revolutions, the return spring 25 , The clutch weight 23 expands in the radial direction, the clutch shoe 24 is pressed against the inner peripheral surface of the clutch outer 21, and the starting clutch 20 is brought into the connected state.

As shown in FIG. 3, a gear transmission 40 is disposed behind the crankshaft 10 in the crankcase 2, and the crankshaft 10 and the gear transmission 40 are arranged.
The main shaft 41, which is the input shaft of 40, and the countershaft 42, which is the output shaft of the gear transmission 40, are arranged in a straight line in the front-rear direction, and are rotatably supported by the crankcase 2.

Further , as shown in FIG. 4, the switching clutch 30 is disposed on the right side of the main shaft 41 of the gear transmission 40, and the drive gear 26 is integrally formed on the left end of the clutch outer 21 of the starting clutch 20. The outer driver 31 of the switching clutch 30 is rotatably fitted to the right side of the main shaft 41 protruding rightward from the crankcase 2, and the inner driver 32 is integrally fitted to the right end of the main shaft 41. The driven gear 27 is integrally attached to the outer driver 31, and the driven gear 27
The clutch gear 21 is meshed with a drive gear 26 integral with the clutch outer 21.

Further, a plurality of clutch friction plates 33 engaged with the outer driver 31 of the switching clutch 30 are provided.
And the plurality of clutch plates 34 engaged with the inner driver 32 are alternately arranged, and the disc portion 31 of the outer driver 31 is arranged.
The pressure plate 35 is fitted to the cylindrical portion 32b of the inner driver 32 so as to be slidable along the center line of the main shaft 41 and located between the a and the disk portion 32a of the inner driver 32,
Inner driver from disc portion 35a of pressure plate 35
Four sleeve portion pressure plates 35b (disposed at equal intervals in the circumferential direction) are protruded to the right through the 32, and a lifter cam plate 36 is bolted to the tip of the sleeve portion 35b of the pressure plate 35. The compression coil spring force 38 loosely fitted to the sleeve portion 35b of the pressure plate 35
The bearing 39 is fitted to the lifter cam plate 36 between the disc portion 32a and the lifter cam plate 36.

Then, a speed change operation mechanism 50 described later is set to a neutral position,
In the state set to one of the first speed steps,... , As described in [0022] and [0023],
Roller 56 pivotally attached to the branching portion 55b of the latch lifter 55
The groove 57b of the lifter cam plate 57 fits and the bearing
Since the shaft 58 of the lifter cam plate 57 fitted to the center of 39 is located rightward by the spring force of the compression coil spring force 38 together with the pressure plate 35 and the lifter cam plate 36, the clutch friction plate 33,
The clutch plates 34 are pressed against each other to generate a frictional force therebetween, so that the switching clutch 30 is brought into a connected state.

However, during the shifting operation of the shifting operation mechanism 50, as described in [0024], the lifter cam
The groove 57b of the plate 57 is disengaged from the roller 56, the lifter cam plate lifts the spring force of the compression coil spring force 38, and the lifter cam plate 57 projects leftward, and the pressure plate 35 and the lifter cam plate 36 also move leftward. As a result, the clutch friction plate 33 and the clutch plate 34 are separated from each other, the frictional force therebetween is reduced or reduced, and the switching clutch 30 is switched to the disengaged state.

As shown in FIG. 3, in the gear transmission 40, a main shaft 41 and a counter shaft 42
When the main gear group 43 and the counter gear group 44 are fitted, respectively, and the shift drum 45 is intermittently rotated about 72 degrees in one direction or the opposite direction by the shift operation of the shift operation mechanism 50, The shift forks 46 and 47 engaged with the shift cam groove 45a of the shift drum 45 move to the right and left as appropriate, and the main gear group 43 and the counter gear group 44 selectively mesh with each other. From the first gear to the second gear, or from the fourth gear to the third gear and the second gear.

FIG. 4 shows the speed change operation mechanism 50 .
As shown, the change spindle 51 is
A change spindle that is rotatably supported by the crankcase 2 in parallel with and projects to the left from the crankcase 2
A change petal (not shown) is integrally attached to the left end of 51, a clutch lever 52 is integrally attached to a right end of the change spindle 51 projecting rightward from the crankcase 2, and a lever pin 53 is provided at a tip of the clutch lever 52. Have been.

[0022] Furthermore, as shown in Figure 4, the pivot shaft 54 to the right crankcase cover 7 is integrally attached positioned on the right extension of the main shaft 41, the clutch lifter 55 to the pivot shaft 54 And the boss 55 of the clutch lifter 55
a is fitted into the hole 7a of the right crankcase cover 7, and a roller 56 is rotatably fitted into a branching portion 55b which branches out from the clutch lifter 55 in three directions.
Of the lifter cam plate 57 in the central shaft portion 55c
57a is rotatably fitted and this lifter cam plate
A radial groove 57b recessed from right to left is formed at a position corresponding to the branching portion 55b of the clutch lifter 55, and an extension 57 of the lifter cam plate 57 is formed in the clutch lifter 55.
c, a guide slot 57d is formed.
Of the lifter cam plate 57 via a roller 53a, and a shaft 58 is integrally protruded leftward from the center hole of the lifter cam plate 57,
The shaft 58 is fitted to the inner ring 39a of the bearing 39.

When no force is applied to a change pedal (not shown), as shown in FIG.
The roller 56 of the branching portion 55b of the clutch lifter 55 drops into the groove 57b of the lifter cam plate 57, and the lifter cam plate 57, the shaft 58, the bearing 39, and the pressure plate 35
Is located on the right side, and the switching clutch 30 is in the connected state.

However, when a change pedal (not shown) is operated, the change spindle 51 is rotated, and the clutch lever 52 is turned, as shown in FIG.
In addition, the lifter cam plate 57 is also swiveled, and the groove 57b of the lifter cam plate 57 causes the protrusion of the clutch lifter 55 to protrude.
55b roller 56 comes off, lifter cam plate 57, shaft
58, the bearing 39 and the pressure plate 35 move to the left, and the switching clutch 30 enters the disconnected state.

As shown in FIG. 4, a spindle positioning plate 60 is integrally mounted on the change spindle 51 between the clutch lever 52 and the crankcase 2 and adjacent to the crankcase 2. A sleeve 61 is rotatably fitted to the change spindle 51 between the crankcase 60 and the crankcase 2, a shift master arm 62 is integrally fixed to the sleeve 61, and the shift master arm 62 is cut to the left at a right angle. Raised piece 62a
And a window 62b is formed, and the tip end 60a of the spindle positioning plate 60 is also bent to the right at a right angle. As shown in FIG. 7 and FIG. A pin 63 projects rightward from the crankcase 2 and is located at an intermediate position between the raised piece 62 a and the bent piece 60 a of the spindle positioning plate 60, and both ends of a coil spring 64 wound around the sleeve 61. 64a and 64b sandwich the cut-and-raised piece 62a of the shift master arm 62, the pin 63, and the bent piece 60a of the spindle positioning plate 60.

Further, the tip portion 62 of the shift master arm 62
c, a base 65a of the shift arm 65 is pivotally mounted. A tension coil spring 66 is stretched between the tip 62d of the shift master arm 62 and the shift arm 65, and an engagement claw 65b is provided near the tip of the shift arm 65 and its center. , 65c are formed,
A shift arm 65 is pressed by a spring force of a tension coil spring 66 against an engagement pin 48 protruding from the right end of the shift drum 45 at substantially equal intervals in the circumferential direction, and the shift master arm 62 is moved forward or rearward of the vehicle body. By one reciprocating swing, the engaging claws 65b, 65c of the shift arm 65 are engaged with the engaging pin 48, and the shift drum 45 is driven to rotate clockwise or counterclockwise by about 72 °. ing.

Furthermore, a star-shaped cam 49 is integrally attached to the right end of the shift drum 45, and a stop plate 67 is pivotally supported on the crankcase 2 at a position below and behind the shift drum 45. A roller 68 is pivotally mounted on the stop plate 67, and the roller 68 of the stop plate 67 is pressed against the star cam 49 by the spring force of a return spring 69 provided at the base of the stop plate 67. It is designed to be held at an angle.

Further, a support shaft 52a is fixed to the clutch lever 52, and a brake lever 71 of a brake mechanism 70 is pivotally supported on the support shaft 52a. The front end of the brake lever 71 is bent at a right angle to the outer surface thereof. A brake lining 72 is provided, and a pin 73 is attached to the clutch lever 52 and the brake lever 71.
And a pin 74 projecting therefrom, the ends 73a, 75b of the coil spring 75 wound around the support shaft 52a,
It is designed to be pinched.

Since the illustrated embodiment is configured as described above, when the gear transmission 40 is set to the neutral stage and the overhead valve type single cylinder internal combustion engine 1 is stopped, the switching clutch 30 is connected. In this state, the starting clutch 20 is in the disconnected state.

When the overhead-valve single-cylinder internal combustion engine 1 starts, the crankshaft 10 rotates, and the clutch outer 21 of the starting clutch 20 even if the starting clutch 20 is disconnected.
Is fitted to the crankshaft 10 and the clutch outer 21 rotates with the frictional force between the two, and rotates in the rotation direction indicated by the arrow in FIG.
The outer driver 31 of the switching clutch 30 which is connected via the shaft also rotates, but when the change pedal is depressed in order to shift up from the neutral gear to the first gear, the clutch lever 52 and the brake lever 71 are shown in FIG. As shown, the brake lining 72 is swung clockwise to press the brake lining 72 against the outer peripheral surface of the clutch outer 21 and the brake mechanism 70
The brake of the outer driver 31 is stopped by the operation of, and the braking mechanism is applied to the stopped counter shaft 42 and the counter gear group 44 connected to the rear wheel of the motorcycle.
Due to 70, the outer driver 31, the inner driver 32 of the switching clutch 30, and the main shaft 41 and the main gear group 43 of the gear transmission 40 do not relatively rotate, and as a result, impact and noise are generated in the gear transmission 40. Therefore, the speed change operation of the speed change operation mechanism 50 is smoothly performed.

When the upshift from the neutral gear to the first gear is completed and the change pedal is depressed, the brake mechanism 70 stops braking the outer driver 31 of the switching clutch 30 and the switching clutch 30 is in the connected state. When the accelerator grip is operated to accelerate the overhead-valve single-cylinder internal combustion engine 1, the starting clutch 20 is gradually connected, and the torque of the crankshaft 10 is reduced.
20, transmitted to the rear wheels via the switching clutch 30 and the gear transmission 40, and the motorcycle can start.

After the motorcycle starts and is accelerated to a certain speed, the accelerator grip is operated in the deceleration direction and the change pedal is operated in the upshift direction, whereby the overhead valve type single cylinder internal combustion engine 1 is operated. At the same time, the brake mechanism 70 operates, and the outer driver 31 of the switching clutch 30 decelerates. Thereafter, the switching clutch 30 is disengaged, and the swing of the shift master arm 62 causes the shift drum 45 to move about 72 °. Rotated, gear transmission 40
Is shifted up from the first gear to the second gear. When the shift pedal is returned after the shift-up is completed, the braking of the switching clutch 30 by the brake mechanism 70 is released and the switching clutch 30 returns to the connected state as described above. You can travel on steps.

As described above, when performing the upshift operation from the neutral gear to the first gear, the first gear to the second gear, etc., the switching clutch 30 is braked by the brake mechanism 70 and the main shaft 41 is decelerated. Therefore, the meshing switching between the main gear group 43 and the counter gear group 44 is smoothly performed, and the generation of impact and noise due to upshifting is suppressed as much as possible.

Conversely, when the change pedal (not shown) is operated in the reverse direction, the clutch lever 52 is swung in a direction away from the switching clutch 30, so that the brake mechanism 70 brakes the outer driver 31. Instead, the downshift is performed by the disconnecting operation of the switching clutch 30 and the reverse rotation of the shift drum 45 by about 72 °.

As described above, in the illustrated embodiment, from the neutral stage
Not only when shifting up to the first gear,
The shift clutch is used even when shifting up to
By temporarily braking the 30 outer drivers 31
Stop the main shaft 41, which is the input member of the gear transmission 40.
Can be stopped or decelerated,
Shift operation always with the same operation feeling even when shifting up
And the gear transmission 40
The peripheral speed of the meshing gear of the gear group 43 and the meshing speed of the counter gear group 44
Since the peripheral speed of the mating gear can be almost matched,
Smoothly shifting gears without generating shock or noise
Can be.

At the time of shifting up, over all the speeds,
All the outer drivers 31 of the switching clutch 30
And shift from neutral to first gear
The outer driver 31 of the switching clutch 30 is
Is not designed to selectively brake
The structure of the operation mechanism 50 is simplified, and the number of parts is reduced.
As a result, cost can be reduced.

Further, even if the brake lining 72 is worn, the function of the coil spring 75 allows the brake lining 72 to always come into contact with the clutch outer 21 of the starting clutch 20, and the braking operation of the brake mechanism 70 varies. Hateful.

[Brief description of the drawings]

FIG. 1 is a right side view of an overhead valve type single cylinder internal combustion engine provided with a vehicle power transmission device according to the present invention.

FIG. 2 is a right side view in which an essential part of FIG. 1 is partially enlarged.

FIG. 3 is a vertical sectional view taken along line III-III of FIG.

FIG. 4 is a vertical sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is a side view of a speed change operation mechanism in a neutral stage.

FIG. 6 is a side view of the speed change operation mechanism in a state where a clutch lever is operated to shift up to the first speed.

FIG. 7 is a side view in a state where a clutch lever, a lifter cam plate, and a brake mechanism are removed in FIG. 5;

FIG. 8 is a side view of FIG. 6 with a clutch lever, a lifter cam plate, and a brake mechanism removed.

FIG. 9 is a side view of a clutch outer, a clutch lever, and a lifter cam plate of a starting clutch in a neutral stage where a shift drum, a star cam, a shift master arm, a shift arm, and a brake mechanism are removed.

FIG. 10 is a side view of the same drawing as FIG. 9 in a state where a clutch lever is operated to shift up to the first gear.

[Explanation of symbols]

1 ... overhead valve type single cylinder internal combustion engine, 2 ... crankcase, 3
... Cylinder block, 4 ... Cylinder head, 5 ... Head cover, 6 ... Left crankcase cover, 7 ... Right crankcase cover, 8 ... Cylinder hole, 9 ... Piston, 10 ... Crankshaft, 11 ... Bearing, 12 ... Crank pin,
13 ... Piston pin, 14 ... Connecting rod, 15 ... Variable venturi carburetor, 16 ... Throttle wire, 17 ...
Drive sprocket, 18 Starter driven sprocket, 19 Generator, 20 Start clutch, 21 Clutch outer, 22 Clutch inner, 23 Clutch weight, 24
... clutch shoe, 25 ... return spring, 26 ... drive gear, 27 ... driven gear, 28 ... pin , 30 ... switching clutch, 31 ... outer driver, 32 ... inner driver, 33 ...
Clutch friction plate, 34 ... Clutch plate, 35 ... Pressure plate, 36 ... Lifter cam plate, 37 ... Bolt, 38 ... Compression coil spring force, 39 ... Bearing, 40 ... Gear transmission, 41 ... Main shaft, 42 ...
Counter shaft, 43: Main gear group, 44: Counter gear group, 45: Shift drum, 46: Shift fork, 47: Shift fork, 48: Engagement pin, 49: Star cam, 50: Shifting operation mechanism, 51: Change Spindle, 52 ... Clutch lever, 53 ... Lever pin, 54 ... Pivot shaft, 55 ... Clutch lifter, 56 ... Roller, 57 ... Lifter cam plate, 58 ... Shaft, 60 ... Spindle positioning plate, 61 ... Sleeve, 62 ... Shift master arm , 63 ... pin, 64 ... coil spring, 65 ... shift arm, 66 ... tension coil spring, 67 ... stop plate, 68 ... roller, 69 ...
Return spring, 70: brake mechanism, 71: brake lever, 72: brake lining, 73: pin, 74: pin, 75: coil spring.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-212675 (JP, A) JP-A-8-104278 (JP, A) JP-A-63-215484 (JP, A) JP-A 8- 233074 (JP, A) Fully open 1988-45443 (JP, U) Fully open, 55-63295 (JP, U) Fully open, 2-87690 (JP, U) Fully open, 60-19846 (JP, U) Japanese Utility Model Application Hei 1-104462 (JP, U) Japanese Utility Model Application Hei 5-42817 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 3/00-3/28 F16H 59/00 -61/12 F16H 61/16-61/36 F16H 63/00-63/38 B60K 41/00-41/22 B62M 25/00-25/06 B60K 17/02

Claims (1)

(57) [Claims] 1. An output member of a starting clutch is relatively rotatably fitted to a crankshaft of an internal combustion engine mounted on a vehicle, and the starting clutch,
A power transmission device for a vehicle in which power is transmitted to wheels via a switching clutch and a gear transmission, wherein each shift up of a shift operation mechanism for changing a gear ratio from a neutral stage to a final shift stage of the gear transmission. Only during operation, a shift switching braking member that applies a braking force to the large diameter portion of the output member of the starting clutch is provided, and the shift switching braking member is directly connected to the clutch operating member of the switching clutch. Conclusion
And the shift clutch is shifted to the upshift operation of each stage.
A power transmission device for a vehicle, wherein braking is performed in conjunction with each other .