JPS62125918A - 4-wheel-drive vehicle for traveling rugged ground - Google Patents

Abstract

PURPOSE:To prevent the interference of a driving system with the foot of a driver by providing a distributing device on the rear side part of an engine, connecting the rear end of the output shaft of said engine to a rear final reduction gear via a rear driving shaft, and connecting the front end of the output shaft of said distributing device to a front final reduction gear via a front driving shaft. CONSTITUTION:The captioned vehicle has two front wheels 36 and two rear wheels 50 each of which has a wide and super-low pressure tire, an engine 58 loaded near the center part of a body frame 10, a straddle type driver's seat 94 provided on the upper part of the engine 58, and a pair of right and left foot rests positioned on the lower side of the engine 58. In this structure, a distributing device 66 is fixed to the rear side part of the engine 58 so as to allow the output shaft 60 of the engine 58 to pass through it, and an output shaft 68 projects out forwardly from the lower part of the distributing device 66. And, a rear driving shaft 64 connects the rear end of the output shaft 60 to the rear final reduction gear 52 in between both the rear wheels 50, while a front driving shaft 76 passed near the lower side of the engine 58 to connect the front end of the output shaft 68 to a front final reduction gear 44 in between both the front wheels 36.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention provides a straddle-type driver's seat above the engine, and allows the driver to ride while placing both feet on a footrest located below the engine. The present invention relates to a four-wheel drive vehicle for traveling on rough terrain.

(Background of the Invention) Two rear wheels for driving on rough terrain, each of which has four wheels equipped with wide ultra-low pressure tires, and a straddle-type driver's seat placed above the engine mounted near the center of the vehicle body frame. There have been conventionally driven four-wheeled vehicles. In this type of vehicle, the driver rides the vehicle with both feet placed on a pair of left and right footrests located below the engine, so the engine is located between the two feet.

For this reason, it is undesirable for the engine width to become large or for there to be a protrusion on the side of the engine where the feet would protrude.

On the other hand, it is being considered to convert this type of vehicle into a four-wheel drive vehicle, but in this case, it is desirable to be able to use conventional two-wheel drive vehicle parts, especially the engine, as is from the viewpoint of improving productivity. In addition, when a conventional engine is used in this way, it is also required that the driver's feet do not easily hit the engine or drive system due to the shift to four-wheel drive.

(Purpose of the Invention) The present invention was made in view of the above circumstances, and it is possible to easily convert a conventional two-wheel drive vehicle to four-wheel drive by using the engine, etc. as is, and to make it possible to easily convert the engine to four-wheel drive. To provide a four-wheel drive vehicle for running on rough terrain in which the engine and drive system do not easily hit the feet of a driver who is not driving.

(Structure of the Invention) According to the present invention, this object has two front wheels and two rear wheels each with wide ultra-low pressure tires, and an engine output shaft mounted near the center of the vehicle body frame and protruding rearward from the rear side. A vehicle comprising an engine, a straddle-type driver's seat disposed above the engine, and a pair of left and right footrests disposed below the engine, wherein the engine output shaft passes through the upper part of the seat. A vertically long distributor fixed to the rear side of the engine and having a distributor output shaft protruding forward at the bottom thereof, and a rear end of the engine output shaft connected to a rear final reduction gear located between both rear wheels. A rear drive shaft, and a front drive shaft that connects the front end of the distributor output shaft to a front final reduction gear located between both front wheels, and the front drive shaft is disposed so as to pass near the lower side of the engine. This is achieved by a four-wheel drive vehicle for traveling on rough terrain.

That is, it utilizes a conventional shaft-drive type rear-wheel drive vehicle, and has a vertically long distributor fixed to the rear side of the engine that extracts front-wheel drive power from the output shaft of the engine. For this reason, the distributor is located behind the footrest on the rear side of the engine, and the front drive shaft also passes near the bottom side of the engine, so the driver's feet do not come into contact with the engine or drive system.

The distributor may include a gear train, a clutch that connects and disconnects the front wheel drive force, or a bidirectional overrunning clutch.

(Example) Fig. 1 is a side view of an embodiment of the present invention, Fig. 2 is a partially sectional plan view, Fig. 3 is a side sectional view of the distributor, and Fig. 4 is the IT-IV line thereof. FIG.

In FIGS. 1 and 2, reference numeral 1o indicates a vehicle body frame, and this frame 10 includes a pair of left and right lower tubes 12 (12a) whose rear portions are bent diagonally upward and rearward.

12b), a pair of left and right front tubes 14 (14a, 14b) bent at a substantially right angle when viewed from the side, a pair of left and right front upper tubes 16 (16a, 16b), and a rear upper tube 18.
(18a, 18b), front tube 20, and rear tube 22 (22a).

22b). The front end of the front tube 14 is fixed to a cross tube 24 that connects the front end of the lower tube 12, and the rear end is fixed to an intermediate portion of the front tube 2o. The upper end of the front tube 2o is fixed to a cross tube 26 that connects the front upper tube 16, and the lower end is fixed to a cross tube 28 that connects the lower tube 12.

A cross tube 30 is fixed to the front end of the upper front tube 10, and its left and right ends and the front tube 14 are connected by a shock absorber tower 32 (only one of which is shown). The rear upper tube 18 is fixed to the rear end of the lower tube 12 and the upper end of the rear tube 22, and its front end is fixed to the rear end of the front upper tube 16 via a cross tube 34.

36 (36a, 36b) are a pair of left and right front wheels with wide ultra-low pressure tires, which are supported by a modified double wishbone type suspension system. That is, the upper part of the knuckle bracket (not shown) of the front wheel 36 is connected to the front tube 14 by an upper arm 38 having an A-shaped path in plan view.
The lower part is connected by a front drive shaft 40 (only one is shown) and a tension rod 42 (42a, 42b).

The inner end of the drive shaft 40 is connected via a cross joint to a front terminal reducer 44 fixed to the lower tube 12, and the outer end is connected to a spindle 46 rotatably held by a knuckle bracket through a seven-figure joint. connected via. Further, a cylindrical shock absorber 48 (48a, 48b) is interposed between the upper arm 38 and the upper end of the shock absorber column '7-32. Note that the final reduction gear 44 may have a built-in differential device.

50 (50a, 50b) are rear wheels with wide ultra-low pressure tires. The rear wheel 50 is fixed to a rear axle 54 protruding from a rear final reduction gear 52, and the rear final reduction gear 52 is integrated with a swing arm 56 that is vertically swingable. Note that this swing arm 56 is supported by a shock absorber 57. Further, the rear final reduction gear 52 may have a built-in differential device.

58 is an engine mounted near the center of the vehicle body frame 10. This engine 58 has an output shaft 60 projecting rearwardly on its rear left side. This rotation of the output shaft 60 is transmitted to the rear final reduction gear 52 via the universal joint 62 and the rear drive shaft 64. Note that the rear drive shaft 64 is inserted through the cylinder on the left side of the swing arm 56. This engine 5
Almost all of the drive systems for the 8 and rear wheels can be those of conventional rear two-wheel drive vehicles.

A distributor 66 is fixed to the rear side of the engine 58 and extends downward across the output shaft 60. This distributor 66 accommodates a float train 70 that transmits the rotation of the engine output shaft 60 to the distributor output shaft 68.

As shown in FIG. 3.4, this gear train 70 includes a second gear 70b fixed to the engine output shaft 60, and a second gear 70b fixed to the engine output shaft 60.
and a third gear 70c fixed to the distributor output shaft 68, which are housed in a case 72 divided into front and rear parts.

This distributor output shaft 68 protrudes forward from the case 72,
Its rotation is controlled by the universal joint 74, the front drive shaft 76, and the universal joint 78.
The signal is transmitted to the front final reduction gear 44 via. Note that this front drive shaft 76 is connected to the engine 5 near the lower side of the engine 58.
8 and the lower tube 12a, and is disposed obliquely when viewed from above so that its front end is close to the center line passing through the vehicle body in the longitudinal direction (see FIG. 2).

In the figure, 80 (80a, 80b) is a pair of left and right footrests, 82 is a carburetor, 84 is an intake air purifier, 86 is an exhaust muffler, 88 is a front fender, 90 is a rear fender, 92 is a steering bar handle, 94 is a straddle-type driver's seat located above the engine 58 and long in the front-rear direction.

According to this embodiment, the output of the engine 58 is transferred to the distributor 66.
The power is distributed between the front wheel drive force and the rear wheel drive force. The front wheel driving force is transmitted to the gear train 70 of the distributor 66, the front drive shaft 76, and the front final reduction gear 44, and is further transmitted from the front final reduction gear 44 to the left and right front wheels 36 via the left and right front drive shafts 40. It will be done. The rear wheel driving force is transmitted to the left and right rear wheels 50 via the rear drive shaft 64, the rear final reduction gear 52, and the rear axle 54, and the rear wheels 50 rotate at the same speed as the front wheels 36.

The front drive shaft 76 is connected to the left lower tube 12a and the engine 58.
Since it is disposed in the space between the front drive shaft 76 and the front drive shaft 76, obstacles on the road surface are less likely to hit the front drive shaft 76 while driving, and the front drive shaft 76 can be protected. Furthermore, since it is located sufficiently inside the footrest 80a, the driver's feet will not come into contact with it.

FIG. 5 is a side cross-sectional view of the second embodiment of the distributor, and FIG. 6 is a cross-sectional view taken along the line -■.

This distributor 66A has a second gear 170b and a third gear 170.
A dog clutch 100 is interposed between the two and c. That is, a sleeve 104 that forms the dog clutch 100 together with the second gear 170b is provided on the shaft 102 of the second gear 170b, and the fork 106 that engages with the sleeve 104 is connected to the operating shaft 108 and the lever 11O from the outside.
The dog clutch 100 is engaged and engaged by moving the dog clutch 100 through the .

According to this embodiment, switching between the rear two-wheel drive and the four-wheel drive is possible by intermittent switching between the drive, the drive, and the switch 100.

Fig. 7 is a side sectional view of the third embodiment of the distributor, and Fig. 8 is a sectional view thereof along the line ■-■.
Bidirectional O/D running clutch 20 between 0C and
0 is inserted. This clutch 200 is the second
A part of the shaft 202 of the gear 270b is made into a regular polygon, and a cage 206 is provided between each surface of the shaft 202 and the inner surface of the clutch gear 204.
rollers 208 held at equal intervals are interposed therebetween, and the cage 206 is brought into sliding contact with a friction ring '210 fixed to the case 72 via a friction shoe 212. This clutch 200 has a shaft 202
The rotation, that is, the rotation from the engine 58 side, is transmitted to the clutch gear 204 side, that is, the front wheel 36 side in both forward and backward directions, but conversely, the rotation is not transmitted from the front wheel 36 side to the engine 58 direction.

Therefore, if you set the reduction ratio of the front and rear drive systems so that the circumferential speed of the front wheels is faster than the circumferential speed of the rear wheels with no slippage on each wheel, the steering wheel will normally behave like a rear two-wheel drive. It provides easy-to-operate steering characteristics, and if the rear wheels slip, the driving force is transmitted to the front wheels, so there is no reduction in performance on rough roads.

FIG. 9 is a side sectional view of a fourth embodiment of the distributor. This distributor 66C is provided with a bidirectional overrunning clutch 300 similar to that of the third embodiment on the distributor output shaft 68C. That is, this clutch 300 has a third gear 370C provided on the output shaft 68C so as to freely rotate.
While the gear 370c is integrally provided with a regular polygon, each face of the polygon and the drum 302 fixed to the end of the output shaft 68C
A roller 306 held by a cage 304 is interposed between the cage 304 and the cage 304, and the cage 304 is brought into sliding contact with a friction ring 308 fixed to the case 72 via a friction shoe 310.

According to this embodiment, the same effects as in the third embodiment can be obtained.

Note that in FIGS. 5 to 9, the same parts as in FIG. 3.4 are given the same reference numerals, so the description thereof will not be repeated.

In each of the above embodiments, the distributor is formed by a gear train, but the present invention also includes a system in which front wheel driving force is extracted using a winding transmission mechanism such as a chain or a belt.

(Effects of the Invention) As described above, the present invention fixes a vertically long distributor to the engine so that the engine output shaft protruding rearward from the rear side of the engine passes through the upper part. The front wheel drive force is taken out from the distributor output shaft that protrudes forward from the distributor output shaft, and the rear wheel drive force is taken out from the rear end of the engine output shaft. The rotation was transmitted to the Here, the front drive shaft was made to pass under the engine. As a result, conventional rear-wheel drive engines and rear-wheel drive systems can be used almost unchanged, greatly improving productivity. In addition, the distributor is located behind the footrest and inside the vehicle body, and the front drive shaft can be placed easily without interfering with the footrest, so the front wheel transmission system does not protrude to the side of the engine. There is no risk of the driver's feet coming into contact with them.

[Brief explanation of drawings]

Fig. 1 is a side view of one embodiment of the present invention, Fig. 2 is a partially sectional plan view, Fig. 3 is a side sectional view of the distributor, and Fig. 4 is a sectional view taken along the line IV-IV. . Fig. 5.6 is a side sectional view of the second embodiment of the distributor and its sectional view taken along the line Vl-Vl, and Fig. 7.8 is a side sectional view of the second embodiment of the distributor.
FIG. 9 is a side sectional view of the fourth embodiment of the distributor. 36...Front wheel, 44...Front final reduction gear, 50...Rear wheel, 52...Rear final reduction gear, 58...Engine, 60...Engine output shaft, 64...Rear Drive shaft, 66.66A, 66B, 66C...Distributor, 68.
68C...Distributor output shaft, 76...Front drive shaft, 80...Footrest, 94...straddle type driving seat, 100...dog clutch, 200.300...bidirectional overrunning clutch.

Claims (4)

[Claims] (1) Two front wheels and two rear wheels each with wide ultra-low pressure tires, an engine mounted near the center of the vehicle body frame and having an engine output shaft protruding rearward from the rear side, and an engine disposed above the engine. A straddle-type operator's seat and a pair of left and right footrests located below the engine, wherein the upper part is fixed to the rear side of the engine so that the engine output shaft passes through, and the lower part is fixed to the front side of the engine. a vertically long distributor having a distributor output shaft protruding from the rear end of the distributor output shaft; A front drive shaft whose front end is connected to a front final reduction gear located between both front wheels, the front drive shaft being disposed so as to pass near the lower side of the engine. 4 wheel drive vehicle. (2) The four-wheel drive vehicle for traveling on rough terrain according to claim 1, wherein the distributor transmits the rotation of the engine output shaft to the distributor output shaft by a gear train. (3) The four-wheel drive vehicle for traveling on rough terrain according to claim 2, wherein the gear train is provided with a clutch that connects and disconnects rotation transmission. (4) The gear train is provided with a bidirectional overrunning clutch that allows the distributor output shaft to rotate at a higher speed than the engine output shaft in the same direction. 4-wheel drive vehicle for driving on rough terrain.