JPS61105280A - saddle type vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention A0 Object of the Invention (1) Industrial Field of Application The present invention relates to a saddle-ride type vehicle used mainly on rough terrain, and particularly to a saddle-ride type vehicle that is mainly used on rough terrain, and in particular, a pair of left and right straddle-type vehicles that are driven by a power unit at the front or rear of the vehicle body. The present invention relates to a vehicle in which the driving wheels of the vehicle are suspended by %AXN, each wheel is equipped with a wide extremely low pressure tire, and a saddle is provided at the middle upper part of the vehicle body, and a step is provided at the lower part of the saddle.

(2) Conventional technology.

Generally, this type of vehicle has a relatively long step,
The operator drives the vehicle while shifting his/her weight forward, backward, left, and right depending on the state of the rough ground and driving conditions, and during driving, one drive wheel is often lifted off the ground.

By the way, in this type of vehicle, there is a
There are two types: one in which the wheels are integrally connected via a common axle driven by a power unit, and the other in which both wheels are connected via a differential gear.

In the former, even if one of the left or right drive wheels leaves the ground, the other drive wheel that is in contact with the ground does not lose its driving force, so it has excellent running performance. During normal cornering, it is not possible to provide a rotational difference between the two drive wheels, resulting in the following inconvenience. In other words, since the tires of each drive wheel are of extremely low pressure type, during normal cornering, when the load on each tire changes due to the influence of centrifugal force acting on the vehicle body, the outer tire on the side where the load increases is compressed and its contact radius rapidly decreases, while the inner tire on the side where the load is reduced expands and its contact radius rapidly increases, creating a large difference in the effective radius of both drive wheels. The difference in the length of the orbits of the inner and outer wheels causes severe slippage between the inner wheels, which have low ground contact force, and the ground f, which can damage the lawn or destroy farm ridges over the wide width of the tire. etc., which will make the ground rough.

On the other hand, with the latter, it is possible to apply relative rotation to both drive wheels even during normal cornering, so it is possible to drive without roughening the ground, but if one drive wheel leaves the ground, the other drive wheel that is on the ground may There are five drawbacks: the drive wheels lose driving force, resulting in poor running performance.

In order to solve these problems, we improved the differential device and
It is known that when a difference in rotational speed occurs between the driving wheels of both layers, the power from the power unit to the driving wheel on the high speed side is cut off (see Japanese Patent Laid-Open No. 136563/1983).

(3) Problems to be Solved by the Invention According to the above-mentioned improved differential system, a shock occurs due to the connection and disconnection of power to the high-speed drive wheel, which is performed in accordance with the rotational speed difference between the two-layer drive wheels. This impairs ride comfort, and when turning, the vehicle is driven only by the inner drive wheels, so it cannot be said that the vehicle has sufficient running performance.

The present invention was made in view of such circumstances.
When turning, both drive wheels can exert driving force while applying relative rotation between both driving wheels, and even when one drive wheel leaves the ground, the driving wheel on the ground side can exert driving force. In this manner, an object of the present invention is to provide a straddle-type vehicle that has high running performance and does not cause roughening of the ground.

B0 Structure of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention provides a pair of left and right drives driven from a power unit to the front or rear of the vehicle body via a differential device. In a straddle-type vehicle, the wheels are suspended to P%h, each wheel is equipped with a wide, extremely low-pressure tire, and a saddle is placed at the middle of the upper part of the body, and a step is placed at the bottom of the saddle. The differential device is characterized in that it is provided with a differential control device that increases the differential torque between both drive wheels in accordance with an increase in the relative rotational speed of both drive wheels.

(2) Effect The differential torque between both drive wheels is controlled by the differential control device so that it increases in accordance with the increase in the relative rotational speed of both drive wheels, so when the vehicle is turning, both drive wheels The differential torque is small, allowing the differential to perform its original differential function, and when either the left or right drive wheel leaves the ground, the differential torque increases immediately and the differential of the differential It is possible to suppress or regulate the dynamic function and continue transmitting driving force to the drive wheel on the ground side.

(3) Examples An embodiment of the present invention will be described below with reference to the drawings.

First, a first embodiment of the present invention will be described with reference to FIGS. 1 to 6. In FIGS. 1 to 3, a straddle-type vehicle is equipped with a power unit P including an engine E in the center of a vehicle body B. A steering wheel //'f is mounted at the front of the vehicle body B, and a pair of left and right driving wheels Wb r , W is mounted at the rear thereof.
r r respectively, and each wheel W-f
, F l r , and F r r are equipped with wide extremely low pressure tires T1, for example, so-called balloon tires with an air pressure of less than 1 kgΔ. Furthermore, a fuel tank Ft, a saddle S, and a cargo platform C are arranged in order from the front in the upper part of the vehicle body B, and a pair of left and right rod-shaped steps st, st are arranged in the lower part thereof.

These steps St and St are performed for the three wheels If, Wlγ, f r r in order to facilitate adjustment of the ground pressure or ground contact state of each wheel 1/'f, IFI r, Fγγ by the operator's weight shift. Triangle T connecting the grounding points of
It is formed to be long so that the tip protrudes outside the region of r.

The steering wheel If is pivotally supported by a front fork Ff connected to the front end of the vehicle body B so as to be steerable. In addition, the drive wheel Fl,
r and Frτ are connected to the rear end of the vehicle body B so as to be able to swing up and down, or are supported by the support tube 1 at the tip of the Yasuoak Fr, and are suspended between the vehicle body B and the rear fork Fr on the longitudinal center line O of the vehicle body B. A spring-loaded shock absorber is installed.

In FIG. 4, drive wheels IFtr, Fr r
A pair of left and right axles 2t, 2τ respectively connected to the axles 2t, 2τ are arranged in the support tube 1 facing each other, and these axles 2z,
A differential device 4 driven by the power unit P via the propeller shaft 3 is interposed between the propeller shaft 3 and the propeller shaft 3. Rear fork F
r is a pair of hollow legs 51.r arranged on the left and right with the shock absorber in between.
5r, and the propeller shaft 3 is arranged in the hollow part of the left leg 5t.

The drive wheels F l r and F r r are provided with brake mechanisms 6 and 6, respectively.

In FIG. 5, the differential device 4 is disposed in a housing 7 integrally formed in the middle portion of the support tube 1. As shown in FIG.

This differential device 4 includes a differential case 9 rotatably supported by a housing 7 via bearings 8 around the axes of both axles 2t and 2γ, an incisor gear 10 formed on the inner circumferential surface of the differential case 9, and It is configured in a planetary gear type, including a first planetary gear 11 that meshes with the internal gear 10, a second planetary gear 12 that meshes with the first planetary gear 11, and a sun gear 13 that meshes with the second planetary gear 12. The differential case 9 is driven by an umbrella-shaped drive gear 14 that meshes with each other in order to drive the differential case 9 at a reduced speed from the propeller shaft 3.
and is connected to the propeller shaft 3 via a ring gear 15. The first and second planetary gears 11, 12 are rotatably supported by a carrier 17 that is spline-coupled 16 to the left axle 2t, and the sun gear 13 is spline-coupled 18 to the right wheel IFrr.

A differential control device 1 is provided between the carrier 17 and the sun gear 13.
9 is provided, and this differential control device 19 is connected to the carrier 17
The clutch outer 21 is connected to the clutch outer 21 and rotatably supported by the housing 7 via a bearing 20, and the clutch inner 22 has a cylindrical shape and is connected to the sun gear 13 and surrounded by the clutch outer 21.

The clutch outer 21 has a cylindrical shape with a bottom, and its open end is relatively rotatably fitted to the inner peripheral surface of the differential case 9 so as to define a sealed oil chamber 23 between the clutch outer 21 and the clutch inner 22.

The sealed oil chamber 23 accommodates a plurality of annular outer clutch plates 24 and inner clutch plates 25 arranged in an overlapping arrangement alternately. When engaged, the inner clutch plate 25 is engaged with the clutch inner 22 via the spline 27 so as to be freely slidable in the axial direction.

Further, the sealed oil chamber 23 is filled with highly viscous oil and a small amount of air that allows the oil to thermally expand.

As shown in FIG. 6A, (I3I), the outer clutch plate 24
The inner clutch plate 25 is provided with a large number of teeth 28 that engage with the spline 26 of the clutch outer 21 and a large number of oil holes 29 that allow the oil to flow therethrough. a large number of teeth 30 that engage;
A large number of oil grooves 31 are provided to allow the oil to flow.

Referring again to FIG. 5, a power take-off shaft 32 is rotatably supported at the rear of the housing 7 via bearings 33,34. This power take-off shaft 32 has two bearings 33.
A driven gear 36 that meshes with the ring gear 15 is integrally formed between 34 and has a joint portion 32α with serrations carved at the rear end. This joint part 32α
protrudes outward from a power outlet 37 that opens in the rear wall of the housing 7, and can be connected to a lawn mower, water sprinkler, tiller, or other attachment via a joint 38 as necessary. 5. When the power take-off shaft 32 is not in use, the power take-off port 37 is closed by a cap 39, and at this time the cap 39 is fixed to the housing 7 with bolts 40.

Further, a trailer hitch H (see FIG. 2.3) is fixed to the rear surface of the housing 7.

An outer lubricating oil chamber 70 is defined within the housing 7 by oil seals 72, 73, 74.75 for lubrication of the differential gear 4 and bearings 8, 20.34, etc., and an inner lubricating oil chamber 70 is defined within the differential case 17. An oil chamber 71 is formed, and both front chambers 70.71 communicate with each other via oil grooves 76 and oil holes 77 provided in the differential case 17 and the clutch outer 21, respectively, in order to allow lubricating oil to flow therebetween. Ru.

Note that 41 in FIG. 5 is a protector plate that covers the lower side of the housing 7.

Next, the operation of this embodiment will be explained.

Now, when relative rotation is applied to the left and right drive wheels Flγ and Frr, the rotation of each planetary gear 11 and 12 causes the clutch outer 21 connected to the left car @2t via the carrier 17 and the right axle 2r to rotate. A similar relative rotation occurs with the clutch outer 21 connected to the outer clutch plate 24, and the outer clutch plate 24 and the inner clutch plate 25 rotate relative to each other while shearing the high viscosity oil interposed between them. At this time, the oil holes 29 and oil grooves 31 of each clutch plate 24.25
retains oil and contributes to effective shearing of the oil.

Therefore, when the oil temperature is relatively low, both driving wheels Wb r
, Wr r, that is, the differential torque, is determined by the shear torque of the oil.

As the relative rotational speed of both driving wheels FZγ and Frr increases, the temperature of the oil increases due to the shear energy received from both clutch plates 24 and 25, and initially the viscosity decreases as the oil temperature rises. However, when the relative rotational speed exceeds a predetermined value, a complicated temperature gradient is created in each clutch plate 24, 25 due to a sudden increase in oil temperature, resulting in distortion and a sudden increase in oil temperature. Due to the synergistic effect with the pressure increase in the sealed oil chamber 23 caused by this, an extremely small gap is created between the adjacent inner and outer clutch plates 24 and 25, and the shearing torque of the oil increases in this area. As a result, as shown by the line α in FIG.
r, F r increases as the relative rotational speed of r increases.

Therefore, during normal turning of the vehicle, extremely different deformations of the extremely low pressure tires T, T of the surface drive wheels Wlr, Wrγ cause a large difference in their effective radii, and due to the action of the differential device 4, the surface drive wheels Wlr .

#Vrr rotates relative to each other, but the differential torque is controlled to be small by the differential control device 19 at the relative rotational speed of the two drive wheels Wlr and Wrτ at that time, so the differential device 4 is originally The drive torque from the power unit P is transferred to the surface drive wheels F l r , W r
It is possible to accurately differentially drive them while transmitting the signal to r.

In addition, either the left or right drive wheel Flr or Irr
When leaves the ground, the surface drive wheels F l r ,
When the relative rotational speed of H'r r increases, the differential torque is immediately increased by the differential control device 19, so the differential function of the differential device 4 is suppressed or regulated, and the drive wheel #/r on the grounding side 1 driving force can be continued to be transmitted to r or Wlr.

And then it surfaced. Even at the moment when the drive wheel Flr or Frr touches the ground, the relative rotational speed of the surface drive wheels Flr and Frr is small, so the surface drive wheel Flr.

The FRR's driving force is almost balanced and does not give a shock to the operator.

Next, a second embodiment of the present invention will be described with reference to FIGS. 7 and 8.

In FIG. 7, the differential device 4 includes a plurality of pinions 45 in the differential case 9 and a pair of left and right side gears 461.4.
The left and right side gears 46t, 461- are spline-coupled 47°48 to the left and right axles 21, 2r, respectively.

The differential control device 19 is provided between the differential case 9 and one side gear 46r on one axle 2r.

That is, the differential control device 19 is fixed to the differential case 9 and rotatably supported by the housing 7 via a bearing 49, and includes a cylinder 50 in which the inside is filled with impregnation oil without any gaps, and a cylinder 50 that extends through the cylinder 50. is fitted onto the axle 2r, and the side gear 46? - a drive cylinder 52 which is spline-coupled 51 to the cylinder 50 and rotatably but not axially movably supported by the housing 7 via a bearing 53; A guide pin 57 is fixed to the cylinder 50 and engages with an endless cam groove 56 on the outer circumferential surface of the piston 55. An orifice 60 is formed in the piston 55 to communicate between the left and right oil chambers 58 and 59 in the cylinder 50.

Further, the cylinder 50 is provided with an auxiliary oil chamber 62 adjacent to one oil chamber 59 with an end wall plate 61 in between.

The end wall plate 61 has a through hole 6 that communicates between the adjacent oil chambers 59 and 62.
3 is drilled. The auxiliary oil chamber 62 is defined by an auxiliary piston 64 that slides into the cylinder 50, and the auxiliary piston 64 is constantly urged in a direction to reduce the volume of the auxiliary oil chamber 62 by the elastic force of a spring 65. . End wall board 61
is slidably splined 66 to the cylinder 50;
A spline 6γ that can engage with the spline 54 of the drive cylinder 52 is formed on its inner peripheral surface. This spline 67 is adapted to engage with the spline 54 of the drive cylinder 52 when the end wall plate 61 moves by a prescribed stroke toward the piston 55 from the normal position where it abuts the shoulder 68 on the inner peripheral surface of the cylinder 50. .

The rest of the structure is the same as that of the previous embodiment, and in the figure, the same reference numerals are given to the parts corresponding to those of the previous embodiment.

The operation of this embodiment will be explained. When relative rotation is applied to the axles 2t and 2γ, the differential case 9 is rotated due to the idle rotation of the pinion 45.
Relative rotation occurs between the cylinder 50 connected to the side gear 46γ and the drive cylinder 52 connected to the side gear 46γ, and the drive cylinder 52 rotationally drives the piston 55, so that the piston 55 moves into the cylinder due to the interaction between the guide pin 57 and the endless cam groove 56. 5
It reciprocates from side to side within 0, and along with that reciprocation, Orice 6
Buffer oil is exchanged between the left and right oil chambers 58 and 59 through the oil chambers 58 and 59 through the oil chamber 21. Generates a differential torque of 'lr.

When the relative rotational speed of both axles 21 and 2r is low, the sliding speed of the piston 55 is also low, so the orifice 6
The damping force generated at 0 is small, and increases as the relative rotational speed increases. .

As a result, as shown in the line in FIG. 8, both axles 2l-2
The differential torque of 2r increases as the relative rotational speed of both axles 2t, 2γ and therefore of both drive wheels increases.

Therefore, similarly to the previous embodiment, when the vehicle turns,
The differential control device 19 controls the differential torque between both drive wheels to be small, and the differential device 4 performs its original differential function. The differential torque is increased and the differential function of the differential device 4 is suppressed or regulated.

Due to this operation of the differential control device 19, the oil chamber 58.5
When the buffer oil in 9 undergoes thermal expansion, the auxiliary piston 64 retreats against the elastic force of the spring 65 and increases the volume of the auxiliary oil chamber 62 in response to the increase in pressure due to the thermal expansion. Thermal expansion of the oil in the oil chambers 58, 59 is transferred to the auxiliary oil chamber 62 through the through hole 63, thereby preventing the pressure in the oil chambers 5B, 59 from increasing excessively.

In this embodiment, the differential gear 4 can be locked by discharging the buffer oil from the cylinder 50. .

That is, when the buffer oil is discharged, as shown in FIG.
is pushed toward the piston 55, so that the spline 67 on the inner circumference of the end wall plate 61 is engaged with the spline 54 of the drive cylinder 52 while the end wall plate 61 remains spline-coupled 66 with the cylinder 50. As a result, the cylinder 50 and the drive cylinder 52 are integrally connected via the end wall plate 61, and the differential case 9 and the side gear 4
6? Since the relative rotation of - is prevented, the rotation of the differential case 9 can always be simultaneously transmitted to both axles 2t and 2γ.

It should be noted that even if the present invention is applied to a straddle-type four-wheeled vehicle equipped with a pair of left and right steering wheels, the same effects as in each of the above embodiments can be achieved. The present invention can also be applied to the driving wheels.

Effects of the C0 Invention As described above, according to the present invention, a pair of left and right drive wheels driven from a power unit via a differential device are suspended at the front or rear of the vehicle body, and each wheel has a wide In a straddle-type vehicle equipped with extremely low-pressure tires, a saddle is disposed at the middle upper part of the vehicle body, and a step is disposed at the lower part of the vehicle body. We installed a differential control device that increases the differential torque between both drive wheels in accordance with the situation, so when the vehicle turns, the differential torque is controlled to a small value, giving the differential device its original differential function and making it easier to roughen the ground. It is possible to continue driving both drive wheels without requiring any skill, and when one drive wheel is lifted off the ground, the differential torque is automatically controlled to a large extent to suppress or regulate the differential function. The drive wheel on the ground-contact side can continue to be driven, resulting in high drivability in any case. Furthermore, when the one drive wheel touches down again on the ground, the relative rotational speed of both drive wheels is low, so the shock of the driving force is extremely small.

[Brief explanation of drawings]

1 to 6 show a first embodiment of the present invention, in which FIG. 1 is a plan view of the straddle-type vehicle, and FIG. 2 is a side view of the same with the front drive wheel removed. , Figure 3 is the rear view of the same,
Fig. 4 is a partially enlarged longitudinal plan view of both the left and right drive wheels and their surrounding areas, Fig. 5 is a longitudinal sectional plan view of the differential gear and the differential control device, and A and @ in Fig. 6 are the differential control device mentioned above. 7 and 8 show a second embodiment of the present invention, and FIG. 7 is a longitudinal sectional plan view of a differential device and a differential control device, FIG. 8 is a sectional view showing a state in which the differential control device operates to lock the differential device, and FIG. 9 is a diagram showing the differential torque characteristics of the present invention, where line α is the first embodiment; This is based on the second embodiment5.
゜B...Vehicle body, E...Engine, P...Power unit, S...Saddle, T...Extremely low pressure tire, Wf.
... Steering wheel, F l r, F r r... 1 drive wheel, St... step 21, 'lr... axle,
4... Differential device, 19... Differential control device Fig. 2 Fig. 1

Claims (1)

[Claims] A pair of left and right drive wheels driven by a power unit via a differential device are suspended at the front or rear of the vehicle body, each wheel is equipped with a wide extremely low pressure tire, and a saddle is mounted on the middle upper part of the vehicle body. In a straddle-type vehicle in which steps are arranged at the bottom of the straddle-type vehicle, the differential device includes a differential control device that increases differential torque between both drive wheels in accordance with an increase in relative rotational speed of both drive wheels. A straddle-type vehicle characterized by being provided with.