JPH11170880A - Power transmitting mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an impulse sound or the like in a dog clutch generated at shift time or acceleration/deceleration time, in a power transmitting mechanism having a V-belt/gear type transmission. SOLUTION: In a power transmitting mechanism transmitting power from an engine to a gear type transmission through a V-belt type automatic transmission T, between a driven pulley 11 of the V-belt type automatic transmission T and an inputting shift shaft 20 of the gear type transmission, a torsional damper 42 damping rotational vibration is provided. In this way, an impact noise or play sound by engaging pawl meshing of a dog clutch generated at shift operation time or acceleration/deceleration time can be reduced. By arranging a fixed shave 33 of the drive pullet 11 in a free end side of a driven shaft 9 and a movable shave 34 movable in an axial direction in a bearing side, assembly workability of the torsional damper is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission mechanism mainly suitable for being mounted on a vehicle, and more particularly to an ATV (all terrain vehicle) for traveling on uneven terrain such as a four-wheel buggy.
The present invention relates to a power transmission mechanism that is suitable for being mounted on a vehicle and that transmits power from an engine to a gear type transmission via a V-belt type automatic transmission.

[0002]

2. Description of the Related Art Conventionally, in a power transmission mechanism of this kind, as a means for smoothly performing a shift operation of a gear type transmission,
Even when the engine is idling, the V-belt type automatic transmission is not completely shut off, and a slight rotation is made within a range where the vehicle does not start moving, thereby engaging the shift sleeve with the dog clutch. Claws (dog teeth)
And the engagement claw of the gear for the gear stage are maintained in a state where they can be easily engaged.

[0003]

(1) In the structure as described above, when idling, V is set until immediately before the shift operation.
The driven transmission of the belt-type automatic transmission and the input transmission shaft of the gear transmission connected to the transmission are rotating slowly. At the stage of engaging, since the rotation of the input transmission shaft is suddenly stopped by the load on the wheel side, a mesh impact sound (metallic sound) is generated at the engaging portion between the engaging claws.

(2) Since the V-belt type automatic transmission is configured not to completely shut off during idling,
Each time the shift operation is performed, the engagement claws of the dog clutch collide with each other, and the engagement claws are worn. In an extreme case, the gear may be disengaged.

(3) The engagement claws of the dog clutch have a large play (play) in the circumferential direction between the engagement claws so that the engagement claws can be shifted smoothly. Then, an impact sound (play sound) is generated from the play. This also causes the engagement claws to wear faster.

[0006] Incidentally, the V-belt type automatic transmission does not seem to cause each of the above problems because the belt itself has a buffering function. However, the V-belt type automatic transmission is not used. Is manufactured with extremely high rigidity in the transfer direction in order to exhibit the shifting function while changing the wheel diameter, and it is not possible to expect the buffering effect of the V-belt itself. In addition, as prior art documents,
JP-A-63-137087 and the like.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the noise of collision between the engaging claws during a shift operation and to reduce the wear of the engaging claws while maintaining the smoothness of the shift operation of the gear transmission. It is an object. It is also an object of the present invention to provide a power transmission mechanism which has good assemblability of a driven gear of a V-belt type automatic transmission and can suppress the amount of deflection of a driven shaft.

[0008]

According to a first aspect of the present invention, there is provided a power transmission mechanism for transmitting power from an engine to a gear type transmission via a V-belt type automatic transmission. A damper device for attenuating rotational vibration is provided between a driven gear of a V-belt type automatic transmission and an input transmission shaft of a gear type transmission.

According to a second aspect of the present invention, a driven shaft of the V-belt type automatic transmission is cantilevered by a bearing, and a damper device is disposed at a free end of the driven shaft. 1. The power transmission mechanism according to 1.

According to a third aspect of the present invention, the fixed sheave of the driven gearbox is disposed on the free end side of the driven shaft, and the movable sheave movable in the axial direction is disposed on the bearing side. 2. The power transmission mechanism according to item 2.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a mechanism explanatory view showing a power transmission system of a motorcycle engine to which the present invention is applied in a skeleton style. The engine comprises a cylinder 1, a piston 2, a crankcase 3, and a crankshaft 4. A transmission case 6 is integrally formed at a rear portion of the crankcase 3, a bell-con case 5 and a bell-con cover 7 are sequentially attached to the right side, and the crankshaft 4 includes a bearing 13.
Are supported at both ends by the crankcase 3.

In the bell-con case 5 and the bell-con cover 7, a drive shaft 8, a driven shaft 9, a drive shed 10, a driven shed 11, a V-belt 12 wound around the two sheds 10, 11 and the like. A V-belt type automatic transmission T is arranged, and a transmission case 6 is provided with an input speed change shaft 20, an intermediate speed change shaft 21, an output shaft 22, and the like. Machine S is arranged.

Referring to FIG. 2, the structure of the V-belt type automatic transmission T will be described in detail. 2 shows a state in which the V-belt 12 is not clamped and the power is cut off, that is, an idling state, for the drive pulley 10, and the driven pulley 11 is located on the front side of the driven shaft O2 ( The state shown on the (drive shaft side) indicates a state in which the effective winding diameter is the maximum, that is, an idling state in which the reduction ratio is maintained at the maximum position, corresponding to the state of the drive shed 10, On the other hand, the state shown behind the driven shaft O2 indicates a state in which the effective winding diameter of the driven gear 11 is minimum, that is, a state in which the reduction ratio is minimum and the vehicle is traveling at high speed.

The drive shaft 8 is taperedly fitted to the right end of the crankshaft 4, is integrally connected by a fastening bolt 17, and is cantilevered by a bearing 18. The drive sheave 10 includes a left fixed sheave 14 and a right movable sheave 15 axially opposed to the fixed sheave 14. The fixed sheave 14 is fixed to the drive shaft 8 in the rotational direction and the axial direction. On the other hand, the movable sheave 15 is
, But is fitted so as to rotate integrally with the drive shaft 8. On the left end surface of the fixed sheave 14, a cooling fan 31 is formed.

On the back side (right side) of the movable sheave 15, a drive adjusting thrust generating mechanism 19 comprising a spider 23, a plurality of governor weights 24, a pressure adjusting spring 25 and the like is provided. The plurality of governor weights 24 are rotatably supported by a plurality of pins 27 provided on the back surface of the movable sheave 15, and expand to the right due to centrifugal force as the number of rotations of the drive shaft 8 increases. It is designed to open. A connecting arm 35 extending rightward through the spider 23 is formed on the rear surface of the movable sheave 15, and the right end of the connecting arm 35 is fitted to the drive shaft 8 movably in the axial direction. The cover 26 is integrally connected, so that the movable sheave 15 and the cover 26 rotate integrally with each other, and can move in the axial direction integrally with the drive shaft 8.

The spider 23 is disposed on the right side of the movable sheave 15 and is integrally fixed to the drive shaft 8 by screw-fitting to the drive shaft 8.
4 is provided with a pressure receiving roller 28 with which the roller 4 contacts. Pressure adjusting spring 2
5 is contracted between the spider 23 and the cover 26, and the cover 26 and the movable sheave 15 integrated with the cover 26 are urged rightward by the pressure adjusting spring 25 to stop the stopper portion 24 a of the governor weight 24. The movable sheave 15 is locked by being pressed against the stopper portion 15a.

That is, when the engine is stopped and idling, the movable sheave 15 is urged rightward integrally with the cover 26 by the pressure adjusting spring 25 as shown in FIG. When the engine rotates and the governor weight 24 starts expanding rightward, the cover 2 is pressed against the pressure adjusting spring 25.
6 and moves to the left integrally with the fixed sheave 14 to narrow the gap.

FIG. 3 is an enlarged sectional view of the driven gear 11 and the driven shaft 9 is also cantilevered by a bearing 77 at the left end. The driven gear 11 includes a fixed sheave 33 on the right side and a movable sheave 34 on the left side, and has a cylindrical cam shaft 38, a roller supporting sleeve 46, a roller 50, and a pressure adjusting spring 4.
9, the power of the belt 12 is transmitted to the driven shaft 9 via a torsion damper 42 disposed at the right end of the driven shaft 9. ing.

The torsion damper 42 is a well-known two-stage type disk type damper, and includes a flange 56 integrally having a hub 55 and a pair of side plates 60 disposed on both axial sides of the flange 56. , Flange 56
And a torsion spring 58 disposed in each of the window holes 62 and 63 of the side plate 60. Hub 55
Are spline-fitted to the driven shaft 9 and are fixed so as not to fall off by bolts 61 and washers. The formed boss portion 65 is connected by a bolt 66. The flange 56 and the side plate 60 are connected to the torsion spring 5.
It can be twisted around the driven shaft center O2 relatively against 8 etc.

FIG. 6 shows the torsion damper 42 of FIG.
FIG. 6 is a view taken in the direction of the arrow VI, and further includes a torsion spring 59 for a second-stage characteristic having a strong spring load in addition to the torsion spring 58 for a first-stage characteristic having a low spring load. When the torsion angle is 0, the springs 58 and 59 abut against the circumferential edge of the window hole 63 of the side plate 60, but the window hole 62 of the flange 56.
The first stage characteristic torsion spring 58 abuts against the circumferential edge of the second stage characteristic, while the second stage characteristic torsion spring 59
Has a certain play M. Reference numeral 67 denotes an elongated hole formed in the flange 56 for regulating the maximum torsion range, and the side plate connecting bolt 66 is inserted therethrough.

That is, in the process of relative torsion between the flange 56 and the side plate 60, when the torsion starts from the torsion angle 0, only the torsion spring 58 for the first-stage characteristic is compressed, and the torsion spring 58 is twisted by a certain angle and the window of the flange 56 Hole 6
After the circumferential edge of the second torsion spring 59 abuts on the second-stage characteristic torsion spring 59, the second-stage characteristic torsion spring 59 is also compressed together with the first-stage characteristic torsion spring 58, thereby limiting the maximum torsional range. It is twisted until the long hole 67 for use and the bolt 66 engage in the circumferential direction.

FIG. 7 is a torsion characteristic diagram. In the section between the torsion angles 0 and θ1, only the torsion spring 58 for the first stage characteristic is compressed. This is a section where the springs 58 and 59 are compressed.

The pressure adjusting mechanism and the lubricating mechanism of the driven gear 11 will be described in detail with reference to FIGS. In FIG. 3, the cam shaft 38 is fitted to the outer periphery of the driven shaft 9 via a pair of left and right bearing metals 36 so as to be axially immovable and rotatable. An annular grease reservoir 37 sealed between the left and right oil seals 39 and 40 is formed between the inner peripheral surfaces. Fixed sheave 33
Is fixedly screwed (screwed) to the outer periphery of the right end of the camshaft 38 and is coupled to the side plate 60 by bolts 66 so as to rotate integrally with the camshaft 38. The pressure adjusting mechanism is configured so that the movable sheave 34 can be spirally twisted with respect to 33.

FIG. 4 is an exploded perspective view of the cam shaft 38 and the sleeve 46.
The roller support holes 53 are formed at three locations at equal intervals in the circumferential direction, and a pair of O-ring fitting grooves 68 are formed on both axial sides of the roller support holes 53, and further, at the right end. Has an integral mounting flange 46b. Three rollers 50 are also provided, and each roller 50 is integrally formed with a small supporting diameter portion 52 via a step portion 50b, and is inserted into a roller supporting hole 53 from a radially inner side to support the roller. It is supported rotatably around the center of the hole. The camshaft 38 has a cylindrical cam groove 5 extending spirally in the axial direction.
Each roller 50 is slidably engaged with the cylindrical cam groove 51 in the axial direction.
The cam action causes the sleeve 46 to move spirally with respect to the camshaft 38.

In FIG. 5, each roller 50 is prevented from coming out radially outward due to centrifugal force or the like due to the contact between the annular step portion 50b and the counterbore surface 53b of the roller support hole 53. Since the outer peripheral surface of the driven shaft 9 faces the inner edge of the roller 50 in the radial direction (the driven shaft core O2 side),
When the engine stops or the like, it is prevented from coming off inward in the radial direction.

In FIG. 3, the inner peripheral boss portion 34b of the movable sheave 34 is fitted to the outer peripheral surface of the sleeve 46 via an O-ring 69, and a bolt 4 is attached to the mounting flange portion 46b.
7 and the camshaft 38 integrally with the sleeve 46.
It makes a spiral motion with respect to. Sleeve 46
Are rotatably and axially movably fitted to the outer peripheral surface of the cam shaft 38 via a pair of left and right bearing metals 48, and annular seals 70 are fitted to the inner peripheral surfaces of the left and right ends of the sleeve 46. An annular grease reservoir 7 having a shallow bottom is provided on a portion of the inner peripheral surface of the sleeve corresponding to the roller support hole 53.
1 is formed. The annular grease reservoir 71 is sandwiched between the pair of O-rings 69. An appropriate amount of grease is applied to the annular grease reservoir 37 between the cam shaft 38 and the driven shaft 9, and grease is also applied to the roller support holes 53. A part of the grease pressed by the grease is held in the annular grease reservoir 71 through a fitting portion of the support hole 53, for example.

The pressure adjusting spring 49 is provided with a spring receiving ring 74 disposed on the left end surface of the inner peripheral boss portion 34b of the movable sheave 34.
And a spring receiving ring 73 locked to the left end of the camshaft 38 by a snap ring 75,
The movable sheave 34 is moved to the sleeve 46 by the pressure adjusting spring 49.
At the same time, it is urged to the right by a constant spring force. When the tension on the tension side of the V-belt 12 increases as the load increases and the movable sheave 34 is twisted in the rotational direction, the cam groove 51 and the roller 5
The movable sheave 34 generates a thrust in a direction to close rightward spirally by the cam action with 0, and in addition to this, a pressure adjusting spring 49
In addition to the spring load, a thrust according to the transmission power is applied.

The gear type transmission will be described in detail. In FIG. 9, the input speed change shaft 2 formed integrally with the driven shaft 9
0 and the intermediate transmission shaft 21 are arranged in parallel with each other, and each of the bearings 7 fitted to the left and right side walls of the transmission case 6.
6, 77 and bearings 78, 79, respectively, and the right end of the intermediate transmission shaft 21 is provided with another output gear chamber 8.
3 The output shaft 22 is connected to the transmission shaft 20,
21, a needle bearing 80 fitted to the right side wall of the transmission case 6, and an output gear chamber wall 84.
Are supported at both ends by a bearing 81 fitted to the bearing. The propeller shaft 16 is rotatably supported by a bearing 82 fitted to the rear wall of the transmission case 6, extends in the front-rear direction, and is always linked to the output shaft 22 via bevel gears 85 and 86. The rear end of the propeller shaft 16 is connected to the rear axle via a final deceleration mechanism (not shown), and the front end is connected to the front wheel propeller shaft via an appropriate universal joint or clutch.

On the input transmission shaft 20, a forward input low gear 90 is disposed at a position close to the right bearing 77, and a forward input high gear 91 is disposed adjacent to the low gear 90. A double reverse input sprocket gear 92 for reverse drive is disposed at a position close to the bearing 76, and one shift sleeve 98 is disposed at a central portion in the axial direction. That is, the reverse input sprocket gear 92 and the forward input gear groups 90 and 91 are separately arranged near the left and right bearings 76 and 77, and the shift sleeve 98 is arranged at the center.

The intermediate transmission shaft 21 includes the input transmission shaft 2.
An intermediate forward low gear 101, an intermediate forward high gear 102, and an intermediate reverse sprocket gear 103 are arranged corresponding to the gears 90, 91, and 92 on the upper gear 0, respectively. Close to the right bearing 79,
The reverse sprocket gear 103 is distributed and arranged so as to approach the left bearing 78. Each gear 101,
The reference numerals 102 and 103 are configured to always rotate integrally with the intermediate transmission shaft 21 by being spline-fitted to the intermediate transmission shaft 21. The intermediate low gear 101 is always meshed with the input low gear 90, the intermediate high gear 102 is always meshed with the input high gear 91, and the reverse intermediate sprocket gear 103 rotates in the same direction as the reverse input sprocket gear 92 via the chain 104. It is linked and linked. An output-side first gear 106 located in the output gear chamber 83 is fixed to the right end of the intermediate transmission shaft 21.
2 is meshed with the second output side gear 107.

In FIG. 10 showing an enlarged view of the input shaft 20, the input-side low gear 90 is integrally formed with an extended boss 109 extending cylindrically to the left, and is rotatable by a pair of left and right needle bearings 94. On the left end side of the extension boss 109, an outward engaging claw 115 for a dog clutch and an inner peripheral notch 11 are provided.
7 is disposed, and the engagement body 11
6 is engaged with the engagement projection 118 formed on the left end surface of the extension boss 109, thereby forming the engagement body 116.
Is always rotated integrally with the extension boss 109. The engaging body 116 is axially locked by a retaining plate 120 and a locking ring 121.

The forward input high gear 91 is rotatably and axially immovably fitted and supported on the outer periphery of the extension boss 109 via a needle bearing 119, and has a left end substantially the same as the gear 91 at the left end. A cylindrical extension 110 extending leftward in diameter is integrally formed, and an inward engagement claw 112 for a dog clutch is integrally formed at the left end of the extension 110. The inner diameter of the inward engaging claw 112 is set slightly larger than the outer diameter of the engaging body 116,
The axial distance D1 between the inward engaging claw 112 and the engaging body 116 is set to be larger than the axial width D2 of the dog clutch engaging claw 123 of the shift sleeve 98. , 115 (D1), it is sufficient that there is a margin for the engagement claw 123 of the sleeve to be in a neutral state once. Specifically, the axial distance D1 is about 1.2 times the axial width D2.

The radial length (thickness) of the engaging claw 123 of the shift sleeve 98 is such that the outer half in the radial direction is substantially engaged with the inward engaging claw 112 for high, and The inner half is dimensioned so that it can engage with the row outward engaging claw 115. In addition, the axial width D2 of the dog clutch engagement claw 123 of the shift sleeve 98 is such that a slightly right portion protrudes beyond the inward engagement claw 112 at the high position as shown in FIG. The notches 136-1, 2, 3, and 4 of the positioning mechanism described later are set at substantially equal intervals, and the shift stroke is divided substantially equally.

FIG. 14 is a view of the forward gear group shown in FIG. 10 as seen from the direction of arrow XIV. For example, six engagement claws 112 and 115 for the dog clutch are formed at equal intervals in the circumferential direction. Is longer than the circumferential width W1 of the engaging claw 123 of the shift sleeve 98 shown in FIG. 15 by a certain distance, and as shown in FIGS. And engaging claw 11 of each gear
2, 115 are engaged with play N in the circumferential direction.

Returning to FIG. 10, the shift sleeve 98 integrally has the forward engaging claw 123 on the right end face as described above, and the reverse engaging claw 124 on the left end face. The reverse engagement claw 124 is freely meshable with an engagement claw 126 formed on the reverse input sprocket gear 92. An annular groove 125 is formed at an intermediate portion of the shift sleeve 98 in the axial direction, and a shift fork 127 is engaged.

The shift fork 127 is connected to the input transmission shaft 2.
The shift rod 128 is fixedly supported by support holes 130 and 131 formed in left and right side walls of the transmission case 6 so as to be slidable in the axial direction. .

Between the shift rod 128 and the transmission case 6, a steel ball 132, a spring 133, and notches 136-1,2,
A positioning and holding mechanism including 3, 4 and the like is provided. The notches 136-1, 2, 3, 4 are provided on the outer peripheral surface of the left end portion of the shift rod 128 in order from the right for reverse use, neutral, high, and low. , 3, and 4 are arranged at substantially equal intervals. A steel ball 132 and a spring 133 are disposed in a hole 137 formed in the transmission case 6, and the spring 133 urges the steel ball 132 toward the shift rod 128, and each notch 136-1, 2, 3, 4 To selectively engage
It locks in that position.

The tip of a shift lever 140 is engaged with an engagement groove 138 formed in the shift fork 127 as shown in FIG. 8, and the shift lever 140 is provided on the upper wall of the transmission case 6. The shift arm 127 is fixed to a lever shaft 141 rotatably supported by a lever holder 142, and the shift arm 127 is moved in the axial direction by rotating the lever shaft 141 by an external shift operation mechanism. Has become.

Next, a lubrication system in the gear type speed reducer will be described. In FIG. 9, the input transmission shaft 20 has a lubricating oil hole 14 communicating from an oil chamber 144 to a lubricating oil passage in the transmission case 6.
3 is formed, and the lubricating oil hole 143 is formed in the low gear 9.
0 and the needle bearing 96 of the reverse sprocket gear 92. Oil is supplied to the oil chamber 144 from an oil passage (not shown).

[0040]

First, the operation of the entire power transmission path will be briefly described. In FIG. 1, the rotational force of the crankshaft 4 is controlled by a drive shaft 8, a drive gear 10,
The transmission is transmitted to the V-belt 12 and the driven gear 11, from the driven gear 11 to the driven shaft 9 via the torsional damper 42, and from the rotation speed and the wheel side in the V-belt type automatic transmission. The automatic transmission is changed according to the load of the gear transmission, and the torsional damper 42 eliminates the generation of the impact noise during the shift of the gear type transmission or the impact noise during the acceleration / deceleration.

The power transmitted from the driven shaft 9 to the input transmission shaft 20 of the gear transmission S is arbitrarily switched from a neutral state to a forward high state, a forward low state or a reverse state by operating the shift fork 127. And the intermediate transmission shaft 2
1 is transmitted to the propeller shaft via the output shaft 22 and the bevel gears 85 and 86.

The operation of the V-belt type automatic transmission will be described.
When the engine is stopped or idling, the drive shed 10 is in the state shown in FIG. 2, the driven shed 11 is in a state in front of the driven shaft O2 in FIG. 2, and the governor weight 24 of the drive shed 10 is closed. As the movable sheave 15 is moved to the right by the pressure adjusting spring 25,
0, the sheaves 14 and 15 are opened to the maximum, the effective winding diameter is minimized, and the V-belt is not clamped and the power is shut off. On the other hand, the driven gear 11 moves the movable sheave 34 to the right by the elastic force of the pressure adjusting spring 49, and has a maximum effective winding diameter. It is in a so-called low state.

When the rotation speed is increased to a certain value, the governor weight 24 rotates clockwise around the pins by centrifugal force, and the movable sheave 15 is moved by the reaction force of the governor weight 24 pushing the roller 72 to the right. It moves to the left against the pressure adjusting spring 25. As a result, the space between the sheaves 14 and 15 is reduced, and the effective winding diameter is increased.

As the diameter of the drive sheave 10 changes, the movable sheave 33 of the driven sheave 11 moves leftward by the V-belt 12 against the spring 49, and the space between the sheaves 33 and 34 is widened. , The effective winding diameter is reduced.

When the vehicle is stationary and the V-belt type automatic transmission T is rotating in an idle state and the gear type transmission S is shifted from the neutral position in FIG.
Is suddenly stopped by the shift from the idling state due to the rotation at the time of neutral as described above. That is, the input transmission shaft 20 and the driven shaft 9 are synchronized with the stationary wheel side by engagement of the dog clutch, so that the torsional damper 42 is used.
Is twisted in the rotational direction with respect to the flange 56 against the first characteristic torsion spring 58, and the inertial energy of the driven gear 11 that is being rotated is gradually absorbed.

Also, if acceleration and deceleration are repeated during traveling in any gear stage, the engagement between the engaging claws of the gear type transmission S has a relatively large play N as shown in FIG. Therefore, the engaging claws 112 and 113 relatively reciprocate in the play N portion and the collision between the engaging claws 112 and 113 is repeated, and a large impact load is repeatedly applied. It can be absorbed by the damper 42. Particularly for a large impact load, the torsion spring 59 for the second stage characteristic shown in FIG. 6 also acts and can be effectively absorbed.

The gear shifting operation in the gear type transmission S will be described in detail. FIG. 9 shows a neutral state. The neutral position of the shift sleeve 98 is maintained by fitting the steel ball 132 into the neutral notch 136-2. The engagement claws 123, 124 of the shift sleeve 98
The power transmission is cut off by the input transmission shaft 20 because neither of the engagement claws 115, 112, 126 is engaged. By shifting the shift sleeve 98 to the right by a predetermined stroke from the neutral position, a forward high state is set.

FIG. 12 shows a forward high state, in which the forward engaging claw 123 of the shift sleeve 98 is connected to the high gear 91.
Of the high notch 136-3
The forward high state is maintained by the steel ball 132 being fitted into the arm. The rotational power of the input transmission shaft 20 is supplied by a sleeve 98, engagement claws (dog clutches) 123 and 112, a cylindrical extension 110, an input high gear 91, and an intermediate high gear 102.
, And transmitted to the output gear 106 via the intermediate transmission shaft 21.

In the operation of the vehicle, normal starting and running are performed in a forward high state, and while the forward high state is maintained, an appropriate wheel rotation speed is obtained by automatic shifting by the V-belt type automatic transmission T. The vehicle is switched to the low state on special road conditions such as steep slopes and uneven terrain. Therefore, normally, as described above, the state is first switched from the neutral position in FIG. 9 to the high state in FIG.

When the shift sleeve 98 is shifted from the neutral position to the forward high position, even if the circumferential phase between the engaging claw 123 of the sleeve 98 and the engaging claw 112 of the high gear 91 is shifted, FIG. As shown in FIG.
12 is configured to engage with a play N in the circumferential direction, so that the state in which the axial edges of the engaging claws 123 and 112 are in contact with each other is maintained for a while, and then the engaging claws 123 and 1 are engaged.
At the time when the phase shifts relatively slightly in the circumferential direction and the phases coincide, the two engaging claws 123 and 112 automatically mesh.

When shifting from the forward high state to the forward low state in FIG. 12, the shift sleeve 98 is further moved rightward from the state in FIG. Set to the low state.

In FIG. 11 showing the forward low state, after the forward engaging claw 123 of the shift sleeve 98 has once passed the intermediate neutral position as described above, the low gear engaging claw 11
5 and the steel ball 132 is fitted into the row notch 136-4, whereby the row position is maintained. Input speed change shaft 2
0 rotation power is sleeve 98, engagement claw (dog clutch)
123, 115, extension boss 109, input low gear 9
0, and transmitted to the output side gear 106 via the intermediate low gear 101 and the intermediate transmission shaft 21.

FIG. 13 shows a reverse state, in which the shift sleeve 98 is moved to the left from the neutral position in FIG.
24 are engaged. The rotational power of the input transmission shaft 20 is transmitted to the output gear 106 via the sleeve 98, the engagement claws 124 and 126, the reverse input sprocket gear 92, the chain 104, the reverse intermediate sprocket gear 103, and the intermediate transmission shaft 21. Is done.

[0054]

[Other Embodiments] In the embodiment shown in FIG. 2, the driven shaft of the V-belt type automatic transmission and the input transmission shaft of the gear type transmission are integrally formed with the same shaft. The present invention can also be applied to a case where the shaft and the input transmission shaft are separate bodies, are arranged parallel or perpendicular to each other, and are connected by gears.

[0055]

As described above, (1) The invention according to claim 1 is a power transmission mechanism for transmitting power from an engine to a gear transmission via a V-belt automatic transmission. Between the driven gear 11 of the automatic transmission T and the input transmission shaft 20 of the gear transmission S,
Since the torsional damper (damper device) 42 for attenuating the rotational vibration is provided, the dog clutch of the gear type transmission S is used when performing a shift operation from an idle state, for example, when shifting from a neutral state to a forward or reverse gear. Can be absorbed by the torsional damper 42. That is, it is possible to reduce the dog impact noise of the dog clutch generated during the shift operation from the idle state.

(2) By repeating acceleration and deceleration during traveling, the torsional damper 42 can also reduce the impact noise generated by the play between the engagement claws of the dog clutch.

(3) By absorbing the impact between the engaging claws as described in (1) and (2) above, the wear of the engaging claws can be reduced, and the gears can be prevented from slipping out.

(4) When the driven shaft 9 of the V-belt type automatic transmission T is cantilevered by the bearing 77 and the torsional damper 42 is provided at its free end as in the second aspect of the present invention, The torsion damper 42 can be easily attached and detached from the free end side as compared with the holding and supporting structure. Further, the driven shaft 9 is cantilevered by the bearing 77 on the transmission case 6 or the like, so that the driven shaft 9 can be separated from the bell-con cover or the like, and the vibration of the V-belt type automatic transmission is prevented from being transmitted to the bell-con cover or the like. Can be prevented from leaking.

(5) While the driven shaft 9 is cantilevered to facilitate the attachment / detachment of the torsion damper 42 as described above, the fixed sheave 33 is moved to the free end side and the movable sheave 34 is moved.
Are arranged on the bearing 77 side, the deflection of the driven shaft 9 can be suppressed.

[Brief description of the drawings]

FIG. 1 is a mechanism explanatory view showing a power transmission system of a motorcycle engine to which the present invention is applied in a skeleton style.

FIG. 2 is a cross-sectional view of the V-belt type automatic transmission shown in FIG. 1 cut along a cut surface passing through each shaft.

FIG. 3 is an enlarged view of a driven gear change portion of the V-belt type automatic transmission shown in FIG. 2;

4 is an exploded perspective view of a pressure adjusting mechanism of the driven vehicle shown in FIG. 2;

FIG. 5 is a sectional view taken along line VV of FIG. 3;

FIG. 6 is a right side view of the torsional damper of FIG. 2;

FIG. 7 is a torsional characteristic diagram of the torsional damper of FIG. 6;

FIG. 8 is a partial vertical sectional view of the gear transmission shown in FIG. 1;

FIG. 9 is a sectional view taken along line IX-IX of FIG.

FIG. 10 is an enlarged view of an input-side transmission shaft portion of FIG. 9;

FIG. 11 is a cross-sectional view of an input-side transmission shaft showing a forward low state.

FIG. 12 is a cross-sectional view of an input-side transmission shaft showing a forward high state.

FIG. 13 is a cross-sectional view of the input-side transmission shaft showing a reverse state.

14 is a side view of the forward gear group of FIG. 10 as viewed in the direction of arrow XIV.

15 is a side view of the shift sleeve of FIG. 10 as viewed in the direction of arrow XV.

FIG. 16 is an enlarged cross-sectional view taken along the line XVI-XVI of FIG. 12, showing a state in which the engagement claws are engaged with each other at the time of forward high.

17 is an enlarged cross-sectional view taken along the line XVII-XVII in FIG. 11, illustrating a state in which the engagement claws are engaged with each other at the time of forward low.

[Explanation of symbols]

Reference Signs List 8 drive shaft 9 driven shaft 10 drive shed 11 driven shed 12 V-belt 14 fixed sheave (drive shed side) 15 movable sheave (drive shed side) 19 drive shed thrust generating mechanism 20 input shifting shaft 21 intermediate Transmission shaft 22 Output shaft 76, 77 Bearing 90 Forward input low gear 91 Forward input high gear 92 Reverse input sprocket gear 98 Shift sleeve 101 Forward intermediate low gear 102 Forward intermediate high gear 103 Reverse intermediate sprocket gear 109 Extended boss Part 110 Cylindrical extension part 112, 115, 126 Engagement claw (dog tooth) of shift gear 123, 124 Engagement claw (dog tooth) of shift sleeve

Claims (3)

[Claims] 1. A power transmission mechanism for transmitting power from an engine to a gear type transmission via a V-belt type automatic transmission, comprising a driven gear of the V-belt type automatic transmission and an input for the gear type transmission. A power transmission mechanism comprising a damper device that attenuates rotational vibration between the transmission shafts. 2. The power transmission mechanism according to claim 1, wherein a driven shaft of the V-belt type automatic transmission is cantilevered by a bearing, and a damper device is disposed at a free end of the driven shaft. . 3. The power transmission mechanism according to claim 2, wherein the fixed sheave of the driven gearbox is disposed on the free end side of the driven shaft, and the movable sheave movable in the axial direction is disposed on the bearing side. .