JP3148704B2 - Transmission for four-wheeled off-road 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 transmission for a four-wheel uneven terrain vehicle (hereinafter simply referred to as a transmission) and a four-wheel uneven terrain vehicle equipped with the transmission. More specifically, a gear-type transmission device is provided for a vehicle equipped with a belt-type continuously variable transmission that travels on uneven terrain, such as sandy ground, uneven ground, rocky hills, and puddle ground. The present invention relates to a four-wheel rough terrain vehicle with a belt-type continuously variable transmission.

[0002]

2. Description of the Related Art A conventional transmission equipped with a four-wheeled all-terrain vehicle is disclosed in Japanese Utility Model Publication No. 1-7883 as a speed change mechanism capable of shifting by one-way operation with a simple structure. As with the transmission for a motorcycle disclosed in the official gazette, a transmission mechanism using a change drum is used. A plurality of cam grooves are formed on the change drum, and a pin of a shift fork for operating a shifter is engaged with each cam groove. Therefore, when the change drum is rotated, the shift fork moves the shifter, and the transmission gear is switched.

[0003] In the case of a motorcycle, when operating such a transmission, the operator depresses or returns a change pedal with his / her foot to rotate the change drum, and returns to the original position by a spring force. By repeatedly operating the pedal in the same manner, the speed is shifted by moving the shift fork so as to obtain a desired deceleration range. Therefore, a plurality of change pedal operations are required to switch to a desired reduction ratio.

In a four-wheel uneven terrain vehicle equipped with a belt-type continuously variable transmission, the change drum is operated by pushing and pulling a tie rod or a push-pull cable by rotating an operation lever at hand of a driver. Is rotating. However, in this case, the rotation (operation) stroke of the operation lever must be increased in order to rotate the change drum so as to cover the entire provided reduction ratio. Therefore, a long stroke operation is required for a vehicle having a narrow space near the driver's seat, such as a four-wheeled all-terrain vehicle, and particularly for a saddle-riding four-wheeled all-terrain vehicle that requires weight shifting when the vehicle is inclined forward, backward, left, and right. It is not preferable to provide a lever.

In order to secure a suitable operation stroke of the operation lever, the size of the change drum becomes large and occupies a considerable space in the transmission gear case. Therefore, the size of the gear case is increased and the weight is disadvantageous.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and the speed can be changed by continuously operating a speed change operation lever in one direction with a short stroke. In addition, the speed change mechanism is simple, lightweight and compact. It is an object of the present invention to provide a transmission suitable for a four-wheel uneven terrain vehicle and a four-wheel uneven terrain vehicle with a belt-type continuously variable transmission.

[0007]

SUMMARY OF THE INVENTION A transmission according to the present invention includes a shifter that moves in an axial direction on a shaft provided with a transmission gear train to release the connection between the transmission gear and the shaft, and the shifter. in the transmission of a four-wheel all terrain vehicle of the type having a plurality of shift forks for moving the shift <br/> motor in the axial direction by moving along the engage and shift rod, the shift Above the rod and on the shift rod
Parallel and almost perpendicular to the longitudinal direction of the shift fork
Is arranged, a flat change plate to have a shaft center of the rotation in the axial direction perpendicular to the direction of the shift rod, said Choi
Radial direction corresponding to the rotation angle formed on the flange plate
And cam guide comprising a groove which changes direction, the protruding toward the shift fork upward, and the guide member for slidably engaging the mosquito Mugaido, outside of the change plate
A detent that can elastically engage with a recess formed in the peripheral edge
Mechanism, and the cam guides correspond to the respective shift forks so that the change plates are mutually rotated.
A plurality of shift forks are formed at positions sandwiching the center, and each shift fork is moved in the axial direction of the shift rod by rotating a change plate.

According to such a configuration, the transmission can be shifted by performing the change operation in one direction, and a transmission having a simple structure can be obtained. Further, since the cam guide position can be formed radially larger with respect to the rotation center of the change plate, the stroke of the speed change mechanism becomes too large even if the multi-stage speed change operation is performed continuously in one direction. Thus, a transmission suitable for an all-terrain vehicle can be realized. Also, for change plate
Since a detent mechanism is provided,
And the shift fork in the switching position
You can decide.

[0009]

[0010]

In addition, when the guided member is constituted by a pin protruding from the shift fork and a bearing slidably fitted on the outer periphery of the pin, the shift fork can move smoothly in the cam guide. Therefore, the shifting operation is smooth.

[0012]

When a convex portion is formed on the change plate, and a shift position detecting mechanism which operates by contacting the convex portion is provided, an output from the detecting mechanism can be easily used for an indicator lamp or the like.

In the four-wheel uneven terrain vehicle with a belt-type continuously variable transmission according to the present invention, a shaft is protruded from a center of rotation of the change plate in the above-described transmission, and extends transversely to the shaft. A lever is provided, and a connecting portion provided on the lever is connected to a shift operation means provided near a driver's seat of the four-wheeled all-terrain vehicle by a push-pull cable. It is characterized in that the gearshift is performed by rotating in one direction.

[0015] With this configuration, in a four-wheel uneven terrain vehicle that is subjected to severe running conditions, a simple configuration enables a reasonable shift operation such as a short stroke one-way operation.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the transmission according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a partial cross-sectional plan view showing an embodiment of a transmission according to the present invention, in which a part is developed. FIG. 2 is a sectional view taken along line AA of the transmission of FIG. FIG. 3 is a sectional view taken along line BB of the transmission shown in FIG. FIGS. 4A and 4B show a saddle-ride type four-wheeled all-terrain vehicle as an example of the all-terrain vehicle in which the transmission shown in FIG. 1 is provided, wherein FIG. It is a side view.

In a saddle-ride type four-wheel uneven terrain vehicle (hereinafter, also referred to as ATV) shown in FIG. 4, a shift lever S disposed below a steering wheel H and beside a fuel tank T is operated in one direction. By doing so, the gear-type transmission 1 can be switched to high-speed forward, low-speed forward, reverse, and neutral stages, and the input side of the gear-type transmission 1 automatically changes the reduction ratio according to the traveling speed. Is connected to the belt-type continuously variable transmission 2.

As shown in FIG. 1, in such a speed change mechanism, the rotational force of the engine E is transmitted from a crankshaft K which is an output shaft of the engine E to a belt-type continuously variable transmission (FIG. 4B).
Is shown only to the belt) 2) to the gear type transmission 1. In the gear type transmission 1, the output pulley shaft 2 a of the belt type continuously variable transmission 2 is connected to the input shaft 3 of the gear type transmission 1.
The input shaft 3 is transmitted to the input shaft 3 and the counter shaft 4, the output shaft 5, the output take-out shaft C,
The power is sequentially transmitted to the propeller shaft P. The input shaft 3, the counter shaft 4 and the output shaft 5 of the gear type transmission 1 are disposed in parallel with each other, and the output take-out shaft C is disposed at right angles to the output shaft 5 via the bevel gear 5b of the output shaft 5. ing.
The counter shaft 4 has a low-speed forward gear 4a and a high-speed forward gear 4b.
A reverse sprocket 4c is rotatably fitted on the counter shaft 4. The input shaft 3 has the low-speed forward gear 4
a and a second gear 3b meshing with the high-speed forward gear 4b are integrally formed, and a sprocket 3c engaged with the reverse sprocket 4c via a chain 3d is connected to the input shaft 3 by spline coupling. It is arranged so as to be able to rotate integrally with it. In the figure, 1a is a gear case.
The input shaft 3, the counter shaft 4, and the output shaft 5 are rotatably supported by the gear case 1a.

A first shifter 6 and a second shifter 7 are spline-coupled to the counter shaft 4 so as to be slidable in the axial direction.
And the tip of the second shift fork 9 is engaged.
The first shifter 6 is integrally formed with a gear 6a that engages with an output gear 5a spline-coupled to the output shaft 5.
The shift forks 8 and 9 have their base ends at the gear case 1a.
And is fitted to a shift rod 10 arranged in parallel with the input shaft 3, the counter shaft 4 and the output shaft 5, and is fitted slidably in the axial direction of the shift rod 10.
The first shifter 6 includes a first shift fork 8 and a shift rod 1.
By moving in the axial direction on 0, the gear is engaged with and disengaged from the low-speed forward gear 4a while being engaged with the output gear 5a. The second shifter 7 is engaged with and disengaged from the high-speed forward gear 4b, and is engaged and disengaged with the reverse sprocket 4c as the second shift fork 9 moves on the shift rod 10 in the axial direction. The first shifter 6 is a low-speed forward gear 4
a, and the second shifter 7 is not engaged with the high-speed forward gear 4b and the reverse sprocket 4c, the gears 4a, 4b and the sprocket 4c
Idles on the counter shaft 4 and the rotational force is not transmitted, so that the neutral state is obtained. The shift rod 10 is fixed to the gear case 1a.

A detent mechanism 11 is formed at the base end of each shift fork 8, 9. The detent mechanism 11 is provided with an engagement groove 1 formed on the surface of the shift rod 10.
1a, an engaging ball 11b provided at the base end of each shift fork, and a coil spring 11c for urging the engaging ball 11b into engagement with the engaging groove 11a. See also FIG. 2). In the present embodiment, the engagement groove 11a is provided between a low-speed advance position and a neutral position of the first shifter 6 on the counter shaft 4 and a high-speed advance position, a reverse position and the neutral position of the second shifter 7 on the counter shaft 4. Each shift rod 10 is formed on the corresponding surface.

Next, a mechanism for switching between the above-described neutral, low-speed forward, high-speed forward, and reverse travels will be described. In this embodiment, as shown in FIG. 2 and FIG.
A flat plate-like change plate 12 is provided above the shift rod in FIG.

At substantially the center of the change plate 12, a shaft 13 projects upward in a direction perpendicular to the flat change plate 12. The shaft 13 is integrally fixed to the change plate 12, and when the shaft 13 rotates, the change plate 12 rotates. Axis 13
Is rotatably supported by the gear case 1a via a bearing 13a and a seal member 13b.

As shown in FIG. 3, around the shaft 13 in the change plate 12, two long portions bent in a predetermined shape so as to change in the radial direction in accordance with the rotation of the shaft 13 are formed. Hole (hereinafter referred to as cam guide) 14
a and 14b are open. On the other hand, engagement pins 15, 16 are provided on the outer periphery of the base end of each of the shift forks 8, 9 toward the change plate 12. Needle bearings 15a and 15b are fitted around the outer circumference of the engagement pin, and the outer circumferences of these needle bearings are respectively penetratingly engaged with the cam guides 14a and 14b. Therefore, when the shaft 13 is rotated integrally with the change plate 12 around its own axis, the shift forks 8 and 9 are moved on the shift rod 10 in the axial direction by the cam guides 14a and 14b.

The shapes of the cam guides 14a and 14b are as follows.
When the shift forks 8, 9 are different, the shifters 6, 7
Is bent into a shape that can be moved to corresponding positions of neutral, low speed forward, high speed forward and reverse. In addition, these cam guides are not particularly limited to holes vertically penetrating the change plate 12, and may be, for example, groove-shaped ones formed on the lower surface of the change plate 12.

Further, a change arm 17 extending in the lateral direction is fixed to the end of the shaft 13 protruding outside the gear case 1a so as to be integrally rotatable with the shaft 13. As shown in FIGS. 3 and 4, the tip of the change arm 17 is connected to a transmission operation lever (also referred to as a shift lever) S disposed below the handlebar H of the ATV and beside the fuel tank T. Tie rods and push-pull cables (indicated by the symbol R in the figure) are connected.
By rotating the shift lever S, the shaft 13 is rotated integrally with the change plate 12, and a shift operation is performed.

As shown in FIG. 3, a detent mechanism 18 is provided on the outer peripheral side of the change plate 12. The detent mechanism 18 is used for the change plate 12
The four engaging recesses 18a formed on the outer peripheral edge of the bracket and the detent case 18b for accommodating the engaging ball 18c at the position of the gear case 1a corresponding to the engaging recesses 18a are fixed. Enclosed engaging ball 18
c and a coil spring 18d which urges the engagement ball 18c so as to press it against the engagement recess 18a.

The four engagement recesses 18a are provided when the change plate 12 is rotated to the neutral, low-speed forward, high-speed forward, and reverse corresponding positions, respectively.
a is formed at a position where it engages with the engagement ball 18c.

Therefore, when the shifters 6 and 7 are shifted to the neutral, low-speed forward, high-speed forward and reverse positions, the detent mechanism 18 of the change plate 12 and the detent mechanism 11 of the shift forks 8 and 9 are moved together. Acts heavily. The formation of the engaging recess is not particularly limited to the outer peripheral edge of the change plate, but may be formed on the upper surface of the change plate 12, for example. In that case, the detent case is disposed downward from above so as to engage the engagement ball with the engagement recess.

The change plate 12 is further provided with a mechanism 19 for transmitting a signal when the change plate 12 reaches the neutral corresponding position and the reverse corresponding position. This transmission mechanism 19
Is an outwardly projecting operation projection 1 formed on the outer peripheral edge of the change plate 12 on the opposite side of the engagement recess 18a.
9a and 2 actuated by the actuation projection 19a
It is composed of a plurality of switches 19b and 19c. These switches 19b and 19c are connected to the change plate 12
Are mounted on the gear case 1a apart from each other so as to oppose the positions of the operation projections 19a at the neutral corresponding position and the reverse corresponding position.

The signal from the transmitting mechanism 19 is transmitted to the panel M below the handle H of the ATV so that the driver can easily see it.
Is transmitted to a display device (not shown) disposed in the display device. The formation of the operation protrusion is not particularly limited to the outer peripheral edge of the change plate, but may be provided on the upper surface of the change plate 12, for example. In that case, the switch is arranged downward or sideways so as to be able to abut the actuating projection.

In the present embodiment, the two cam guides 14a and 14b are formed on the change plate 12. However, the number of cam guides is not limited to two, and the number of cam guides and the number of shift forks are changed in accordance with the number of shift stages. It is easy to increase or decrease. That is, for example, when the number of shift forks is four, the cam guides 14a and 14b in FIG.
A new cam guide having a length corresponding to the same rotation angle as those of the cam guides 14a and 14b may be formed on the outside of each of the cam guides (on the side opposite to the shaft tied to each cam guide).

[0033]

According to the present invention, the transmission mechanism of the transmission can be simplified, reduced in size and weight, and can be easily manufactured. Furthermore, since the operation lever can be operated continuously in one direction and the operation stroke can be shortened, a shift operation device suitable for a four-wheel terrain traveling vehicle can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a partially expanded plan view showing a part of a transmission according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of the transmission shown in FIG. 1;

FIG. 3 is a sectional view of the transmission shown in FIG. 2 taken along line BB.

FIG. 4 shows a saddle-ride type four-wheeled all-terrain vehicle as an example of the all-terrain vehicle in which the transmission shown in FIG. 1 is provided;
(A) is a schematic plan view, (b) is a schematic side view.

[Explanation of symbols]

 1 ... Gear-type transmission 1a ... Gear case 2 ... Belt-type continuously variable transmission 3 ... Input shaft 3a ... First gear 3b ... Second gear 3c ... Sprocket 3d Chain 4 Counter shaft 4a Low speed forward gear 4b High speed forward gear 4c Reverse sprocket 5 Output shaft 5a Output gear 5b Bevel gear 6 first shifter 6a gear 7 second shifter 8 first shift fork 9 second shift fork 10 shift rod 11 ..Detent mechanism 11a ... engaging groove 11b ... engaging ball 11c ... coil spring 12 ... change plate 13 ... shaft 14a, 14b ... cam guide 15 ... Engagement pin 15a: Needle bearing 6 ··· Engaging pin 16a ··· Needle bearing 17 ··· Change arm 18 ··· Detent mechanism 18a ··· Engaging recess 18b ··· Detent case 18c ··· Engaging ball 18d ... Coil spring 19 ... Transmission mechanism 19a ... Operation protrusion 19b, 19c ... Switch

Claims (4)

(57) [Claims] 1. A shifter that moves in an axial direction on a shaft on which a transmission gear train is disposed to disengage a transmission gear from the shaft, and engages with the shifter and moves along a shift rod. You
In the transmission of a four-wheel all terrain vehicle of the type having a plurality of shift forks for moving the shifter in the axial direction by Rukoto, a top of the shift rod, parallel to the shift rod
And substantially perpendicular to the longitudinal direction of the shift fork.
Is a flat plate-like change plate to have a shaft center of the rotation in the axial direction perpendicular to the direction of the shift rod, which is formed in the change plate, corresponding to the rotation angle
A cam guide consisting of a groove that changes in the radial direction and the shift fork protruding toward the change plate
Has been, and the guide member for slidably engaging the mosquito Mugaido elasticity to the formed outer periphery of the change plate recess
And a detent mechanism that can be engaged with each other, so that the cam guide corresponds to each shift fork ,
A plurality of shift forks are formed at positions sandwiching the rotation center of the change plate with each other, and each shift fork is moved in the axial direction of the shift rod by rotating the change plate. Transmission for a four-wheeled off-road vehicle. Wherein said guided member is slidably shifting a four-wheel all terrain vehicle according to claim 1 Symbol placement consisting of fitted by bearings on the shift fork to the outer periphery of the projecting pin whose and the pin apparatus. 3. has a convex portion is formed in the change plate, a four-wheel all terrain vehicle according to claim 1 Symbol placement shift position detecting mechanism operated is disposed by contacting the convex portion Transmission. 4. are projected axes on the center of rotation of the change plate in the transmission according to any one of of the preceding claims 1 to 3, distribution lever extending transversely to the axis And a connection portion provided on the lever and a shift operation means provided near the driver's seat of the four-wheel terrain traveling vehicle are connected by a push-pull cable,
A four-wheel uneven terrain vehicle with a belt-type continuously variable transmission, wherein the speed is changed by rotating the speed change operation means in one direction.