JPH06517B2 - Vehicles for running on rough ground - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle for traveling on a wasteland having a pair of left and right rear wheels.

There is a vehicle for rough-terrain traveling in which a final reduction gear mechanism is provided on a rear axle to which a pair of left and right rear wheels are attached, and the rotation of the engine is transmitted to this final reduction gear mechanism via a chain, a drive shaft, etc. to drive the rear wheels. . In this type of vehicle, an ultra-low pressure tire having a relatively small diameter may be used, but when the rear wheel has a small diameter, the final reduction gear mechanism provided on the rear axle approaches the road surface. For this reason, the bottom of the final reduction mechanism easily hits the convex part of the road surface when running on a road surface with severe undulations, or when straddling the convex part of the road surface with both rear wheels entering the rut. The speed reduction mechanism may be damaged.

On the other hand, in a conventional vehicle, a chain and a drive shaft that transmit the rotation of the engine to the final reduction gear are arranged parallel to the center axis of the vehicle body in the front-rear direction.

Therefore, the position of the final reduction mechanism in the left-right direction is determined by the engine width. For example, in a vehicle that sits astride the seat above the engine, the engine width is also narrowed, and this mechanism must be placed near the center of the vehicle body. Therefore, there is a problem that the position of the final reduction gear mechanism is far from both rear wheels, and the final reduction gear mechanism is more likely to contact the road surface convex portion.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle for rough terrain traveling in which a final speed reduction mechanism provided on a rear wheel is less likely to hit a convex portion or an obstacle on a road surface.

According to the present invention, an object of the present invention is to provide a pair of left and right rear arms that are obliquely supported so that a front end thereof is supported on the vehicle body side and a rear end thereof is displaced to the outside of the vehicle body, and inside one of the rear arms, A drive shaft for transmitting engine power is inserted, and a final reduction gear case is provided at the rear end portion of the rear arm, and one rear axle extends between the final reduction gear case and the rear end portion of the other rear arm. Rotatably around the axle, and the left and right rear wheels that rotate integrally with the rear axle are attached to both ends of the rear axle, while the final reduction gear case rotates integrally with the drive shaft. A small reduction gear and a large reduction gear that meshes with the small reduction gear are accommodated, the rear axle is passed through the center of the large reduction gear, and the outer periphery of the rear axle is penetrated through the rear axle of the large reduction gear. Spline join to Provided integrally with the spline tube which,
This is achieved by a vehicle for traveling on rough terrain, which is characterized in that the spline cylinder is extended on the rear axle to a position intersecting the center line of the drive shaft.

Hereinafter, the present invention will be described in detail based on the illustrated embodiments.

FIG. 1 is a side view showing an embodiment of the present invention, FIG. 2 is a plan view with a part thereof omitted, and FIG. 3 is a plan view of an essential part with a part thereof cross-sectioned. In these drawings, reference numeral 10 is a vehicle body frame. The body frame 10 includes a steering shaft tube 12 located at a front end thereof and a main pipe 14 extending rearward from the steering shaft tube 12.
And a pair of left and right downcomers 16 (16a, 16b) extending obliquely rearward and downward from the steering shaft cylinder 12, and a seat pillar pipe 18 (18a, 18b) extending obliquely rearward and downward from the main pipe 14.
And a seat rail 20 (20a, 20b) extending rearward from the seat pillar pipe 18, and a rear pipe 22 (22a, 22b) extending diagonally forward and downward from the seat rail 20. The rear end of the downcomer pipe 16 and the lower ends of the seat pillar pipe 18 and the rear pipe 22 are connected to the bracket 24 (24 a, 24 a).
It is fixed to b).

26 is a rear arm assembly, which includes a front cylinder 28, a rear cylinder 30,
A pair of left and right rear arms 32, 34 form a substantially trapezoidal shape, and its front cylinder 28 is supported by the bracket 24 by a pivot shaft 36 (36a, 36b). As a result, the rear arm assembly 26 can swing up and down about the pivot shaft 36. A rear axle 38 is rotatably held on the rear cylinder 30 by bearings 39 (39a, 39b),
Rear wheels 40 (40a, 40b) having wide and small diameter ultra-low pressure tires are attached to the left and right ends of the rear axle 38. The rear arms 32, 34 are positioned obliquely with respect to the center axis of the vehicle body in the front-rear direction so that the rear ends of the rear arms 32, 34 are offset more toward the vehicle body side than the front ends thereof. That is, the rear arm 32,
The interval of 34 is wide at the rear part.

A final speed reduction mechanism 42 is provided at a connecting portion between the rear arm 32 and the rear cylinder 30. The mechanism 42 includes a flange 44 fixed to the left end of the rear cylinder 30, an inner lid 46 fixed to the flange 44, a large reduction gear 48 rotatably held by the inner lid 46, and a boss portion of the gear 48. A spline tube 50 fitted and fixed to the spline tube, a case 52 that rotatably holds the spline tube 50 and covers the gear 48, and a gear 48
And a pinion shaft 56 formed with a pinion 54 that meshes with. The case 52 is attached to the inner lid 46 and the flange 50.
Forms a final reduction gear case that houses the final reduction gear. The spline cylinder 50 extends to a position intersecting the center line of the drive shaft 84 described later. The rear axle 38 includes a spline cylinder 50, an inner cylinder 58 as a spacer for properly maintaining the inner ring spacing of the bearings 39a and 39b, and a boss 6 of the brake disk 60.
2 respectively. Between the stepped portion 63 of the rear axle 38 and the nut 64, the inner ring of the bearing 39a, the inner cylinder 58, the bearing 3
The inner ring 9b and the boss 62 are held in order, and the spline tube 5
0 and the boss 62 are splined to the rear axle 38.

A cushion unit 64 is mounted between the rear arm assembly 26 and the main pipe 14, and this unit 64 gives the rear arm assembly 26 a habit of returning in the clockwise direction in FIG.

Reference numeral 66 denotes an engine, which is the main pipe 14 and the downcomer pipe 16.
It is mounted in a space surrounded by the sheet pillar tube 18. The engine 66 is equipped with a constant mesh transmission,
The rotation of the sub shaft 68 (FIG. 3) of this transmission is transmitted by a bevel gear 74 to a bevel gear 72 rotatably held by an engine output shaft 70. The output shaft 70 is arranged in parallel with the longitudinal center axis of the vehicle body. This output shaft 70
The cam cylinder 76, which is splined upward, is pressed against the cam surface 80 of the bevel gear 72 by the spring 78.
And the bevel gear 72 form a cylindrical end surface cam mechanism 82. The cam mechanism 82 has a function of absorbing a shock caused by sudden acceleration / deceleration of the rear wheel 40. A drive shaft 84 is arranged in the rear arm 32. The front end of the drive shaft 84 is connected to the output shaft 70 by a cardan joint 86, and the rear end thereof is connected to the pinion shaft 56 by a gear type joint 88. The drive shaft 84, like the rear arm 32,
The rear end is arranged obliquely with respect to the center axis of the vehicle body so that the rear end is displaced to the side of the vehicle body from the front end.

In FIG. 1, 90 is a front fork, 92 is a front wheel, 94 is a steering wheel, 96 is a rear fender, 98 is a driving seat,
100 is a fuel tank, and 102 is a battery. Battery 1
02 is attached to the main frame 10 so as to be located above the rear arm 34, and balances the weight of the drive shaft 84, the final reduction mechanism 42, and the like arranged on the rear arm 32 side with the weight of the battery 102. There is.

Next, the operation of this embodiment will be described. The rotation of the engine 66 is controlled by the auxiliary shaft 68, the output shaft 70, the cardan joint 86, the drive shaft 8.
4, the gear type joint 88, the pinion shaft 56, and the pinion 54, and is transmitted to the reduction gear 48, and is further transmitted to the rear axle 38 and the rear wheel 40 by the spline cylinder 50. When the rear wheel 40 rides on the convex portion of the road surface during traveling, the impact is absorbed by the deformation of the tire and the upward rotation of the rear arm assembly 26. Considering now that only the rear wheel 40a on the left side rides on the convex portion of the road surface, the central portion of the rear axle 38 moves upward by half the upward movement amount of the rear wheel 40a.
When the final reduction gear mechanism 42 is brought closer to the rear wheel 40a side as in this embodiment, the upward movement amount of the final reduction gear mechanism 42 also increases. Therefore, the lower end of the final reduction gear mechanism 42 is less likely to hit the road surface convex portion.

FIG. 4 is a sectional view showing the vicinity of the final reduction mechanism 42A of another embodiment. In this embodiment, the case 52A is fixed to the rear cylinder 30A of the rear arm assembly 26A, the large reduction gear 48A is meshed with the pinion 54 from the outside of the vehicle body, and the side lid 46A is mounted from the rear wheel 40a side. Therefore, the rear wheel 4
The gear 48A can be attached / detached by removing 0a and the side cover 46A, which improves the maintainability. In addition, large reduction gear 4 with large diameter
8A is further deviated to the side of the vehicle body as compared with the embodiment shown in FIGS. 1 to 3, a cover 52 for covering the gear 48A is provided.
The large diameter portions of A and the side lid 46A can be brought closer to the rear wheel 40a, and the effect of the present invention becomes more remarkable. Further, one of the bearings 39A that supports the rear axle 38A
Since 9Aa is provided on the side lid 46A, the bearings 39Aa, 39Aa
The Ab spacing increases. For this reason, the rear wheel 40 has the rear axle 38A.
It is advantageous in terms of the rigidity of the suspension system against the bending moment applied to. In the present embodiment, the rear axle 38A is inserted from the side of the rear cylinder 34 opposite to the large reduction gear 48A, and the large reduction gear 48 is inserted.
Since the rear wheel 40a side is thinner than A than the rear wheel 40b side, the difference in the torsion spring coefficient between the gear 48 of the rear wheel shaft 38A and each of the rear wheels 40a and 40b can be reduced, and the imbalance of the transmission torque can be suppressed. it can.

The present invention is particularly effective in the case where the lower end of the final reduction mechanism projects downward from the bottom of the engine 66 at all times or during rocking. Further, the present invention can be applied not only to a three-wheeled vehicle but also to a four-wheeled vehicle having two front wheels, and it goes without saying that this case is also included.

As described above, according to the present invention, the rear ends of the left and right rear arms are obliquely arranged so as to be displaced to the outside of the vehicle body, the drive shaft is inserted into one of the rear arms, and the final reduction gear case is brought close to one of the rear wheels. It was made. As a result, the road surface convex portion is less likely to hit the final reduction gear mechanism, and damage to this mechanism can be prevented. Also, since a spline cylinder is integrally provided at the center of the large reduction gear, and this spline cylinder is splined to the rear axle and extended to a position intersecting the center line of the drive shaft, The central portion can be effectively used, and the final reduction gear mechanism can be downsized. For this reason, this mechanism is less likely to hit an obstacle.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of the present invention, FIG. 2 is a plan view with a part omitted, FIG. 3 is a plan sectional view showing a part of it in an enlarged manner, and FIG. 4 is another embodiment. FIG. 3 is a partial plan sectional view of FIG. 32, 34 ... Rear arm, 38, 38A ... Rear axle 40 ... Rear wheel, 42, 42A ... Final reduction gear mechanism, 48 ... Large reduction gear 50 ... Spline cylinder 52, 52A ... Case that is a part of final reduction gear case, 54 … Small reduction gears, 66… Engine 84… Drive shaft.

Claims (1)

[Claims] 1. A pair of left and right rear arms, each of which has a front end pivotally supported on the vehicle body side and a rear end obliquely extended to the outside of the vehicle body, transmits engine power to the inside of one of the rear arms. The drive shaft to be inserted is inserted, and a final reduction gear case is provided at the rear end of this rear arm.
A single rear axle is rotatably provided around the final reduction gear case and the rear end of the other rear arm in an axially rotatable direction, and left and right that rotate integrally with the rear axle at both ends of the rear axle. While attaching the rear wheel, in the final reduction gear case,
A small reduction gear that rotates integrally with the drive shaft and a large reduction gear that meshes with the small reduction gear are accommodated, and the rear axle is passed through the center of the large reduction gear, and the rear axle of the large reduction gear is A vehicle for running on rough terrain, characterized in that a spline cylinder, which is spline-joined to the outer periphery of the rear axle, is integrally provided in the penetrating portion, and the spline cylinder is extended to a position on the rear axle that intersects with the center line of the drive shaft. .