JPS61282645A - Differential gear with differential limiting clutch - Google Patents

Abstract

PURPOSE:To enhance the driving maneuverability of a saddle riding type vehicle by operating a differential limiting clutch by the discharge oil pressure of a pump which is driven in response to the relative rotation of two transmission parts so that the differential limiting function is developed when the relative number or revolutions exceed a prescribed value. CONSTITUTION:A differential limiting clutch 15 is arranged between a differential case 10 as a relatively rotatable transmission part on one side and a side gear 12r as a transmission part on the other side. In this differential limiting clutch 15, a thrust piston 18 which is energized by a spring 26 in such direction as a friction engaging condition is released is provided. On the other hand, a gear pump 28 which is driven by the relative rotation of both transmission parts 10 and 12r is provided. And it is so arranged that the gear pump 28 exerts the discharge oil pressure on the thrust piston 18 via a control mechanism when the relative number of revolutions exceeds a prescribed value so as to bring the differential limiting clutch 15 into a friction engaging condition.

Description

Detailed Description of the Invention A0 Object of the Invention (1) Industrial Field of Application The present invention provides a first transmission member which is provided between two relatively rotatable transmission members and which is spline-engaged with one of the transmission members. A clutch plate, a plurality of second clutch plates that are overlapped with the first clutch plate and spline-engaged with the other transmission member, and both the clutch plates are pressed against each other for frictional engagement. The present invention relates to a differential gear with a differential limiting clutch in which a differential limiting clutch is interposed, which includes a pressing member movable between a position where the frictional engagement is applied and a position where the frictionally engaged state is released.

(2) Prior Art Conventionally, in such a differential device, a differential limiting clutch is configured to perform a differential limiting operation from the time when a differential operation of the differential device occurs.

(3) Problems to be Solved by the Invention By the way, when a differential device is mounted on, for example, a straddle-type vehicle, when turning at extremely low speeds, that is, the difference in rotation between the left and right drive wheels is relatively small (for example, 20 rpyr
(below), it is better not to have a conventional differential limiting clutch as it will not damage the lawn, etc., and depending on the application, not having a differential limiting clutch may produce better results. On the other hand, a differential limiting clutch is required when driving at medium to high speeds, especially when driving with one drive wheel floating, when making sharp turns, or when one drive wheel is on ice. When the dynamic rotational speed is high, it is desirable that the differential limiting function be exhibited.

The present invention has been made in view of such circumstances, and has two
It is an object of the present invention to provide a differential device with a differential limiting clutch that causes the differential limiting clutch to exhibit a differential limiting function after the relative rotational speed of two transmission members exceeds a set value.

B0 Structure of the Invention (1) Means for Solving the Problems According to the present invention, the pressing member is biased by a spring toward a position where the frictional engagement state is released, and the pressing member is biased toward a position opposite to both clutch plates. is provided with a hydraulic chamber, and is configured to operate the pump according to the relative rotation of both transmission members; The control mechanism is connected via a control mechanism configured to supply hydraulic pressure to the hydraulic chamber to move the pressing member toward the frictional engagement position against the biasing force of the spring.

(2) Operation As the two transmission members start relative rotation, the pump also starts pumping, but the hydraulic pressure supplied to the hydraulic chamber remains low due to the action of the control mechanism, and the differential limiting clutch The pressing member does not move toward the frictional engagement position. However, when the relative rotational speed of both transmission members exceeds the set value, the control mechanism supplies high oil pressure to the hydraulic chamber, moves the pressing member to the friction engagement position, and reduces the differential of the differential limiting clutch. The motion restriction function is activated.

(3) Embodiment An embodiment of the present invention applied to a straddle-type vehicle will be described below with reference to the drawings. First, in FIGS. 1, 2, and 3, a body B of a straddle-type vehicle is equipped with a power unit P including an engine E in its center,
A single steering wheel Wf is suspended at the front of the vehicle body B.
At the rear of the vehicle is a pair of left and right drive wheels. r, Fy
r is suspended. Each wheel F f , F l r ,
A wide extremely low pressure tire T, for example, a so-called balloon tire with an air pressure of less than IIcy/cm 2 is mounted on F r r. Further, 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 and st are arranged in the lower part thereof. These steps St and St are each wheel If due to the weight shift of the operator.

To facilitate adjustment of the ground pressure or ground contact condition of F73r, Fτr, each wheel Ff, Flr
It is formed long so that its tip protrudes outside the area of the triangle Tτ connecting the ground points of I F r r.

The steering wheel Wf is pivotally supported by a front fork Ff that is steerably connected to the front end of the vehicle body B. Drive wheels Wlτ, Fτr
The suspension system consists of a rear fork Fr and a shock absorber with a suspension spring, and both driving wheels Wlr and Wrr are connected to the rear end of the vehicle body B so as to be able to swing up and down, and a support tube 11.1r at the lower end of the fork Fr The shock absorber is interposed between the vehicle body B and the rear fork Fr on the longitudinal center line O of the vehicle body B.

In FIG. 4, a pair of left and right axles 2no and 2f connected to the driving wheels F13rpFdeτ, respectively, are opposed to each other and are connected to the support tube 11! , 1r, and these axles 21, 2 . Between r is the propeller l from the power unit P.
A differential gear 4 driven via the shaft 3 is interposed.

The rear fork Fr has a pair of left and right hollow legs 5A on both sides of the vertical center line 0! , 5r, and the left leg 5! A propeller @3 is disposed in the hollow part of.

In FIG. 5, the differential gear 4 is disposed in a housing T to which the inner end of the support tube 11.degree. 1r and the lower end of the hollow leg 51 are respectively fixed. This differential device 4 is connected to the axle 2
A well-known bevel gear is constructed from a differential case 10 rotatably supported by a housing 7 around the axes 1 and 2r, a plurality of binions 11 disposed within the differential case 10, and a pair of left and right side gears 121. It is composed of a type. A ring gear 13 is fixed to the differential case 10, and this ring gear 13 meshes with a drive gear 14 (see FIG. 4) integrated with the propeller shaft 3. Further, the left and right side gears 121, 12r are spline-coupled to the left and right axles 2C2r.

In such a differential device 4, a differential limiting clutch 15 is interposed between two relatively rotating transmission members. The differential limiting clutch 15 includes a plurality of first clutch plates 16 that are spline-engaged with the differential case 10 as one transmission member, and overlapped between each of the first clutch plates 16 and as the other transmission member. Between the position where the plurality of second clutch plates 17 spline-engaged with the side gear 12τ and the first and second clutch plates 16.17 are brought into pressure contact with each other and frictionally engaged, and the position where the frictionally engaged state is released. and a pressing piston 18 as a pressing member that is movable.

That is, the differential case 10 has a cylindrical outer cylinder part 19 and an inner cylinder part 20 extending concentrically and integrally extending along one axle 2r, and the outer cylinder part 19 has a cover 21 at its tip. Obstructed. The outer cylindrical portion 19 functions as a clutch outer in the differential limiting clutch 15, and the first clutch plate 16 is spline-engaged with the inner surface of the outer cylindrical portion 19. Further, a clutch inner 22 is spline engaged with the side gear 12r between the inner cylinder portion 20 and the cover 21, and the second clutch plate 17 is spline engaged with the clutch inner 22. Moreover, although the clutch inner 22 is spline-engaged with the side gear 12y, it is prevented from moving in the axial direction by the inner cylinder portion 20 and the cover 21, and the clutch inner 22 is substantially connected to the side gear 12y.
It is integrated into 2r.

The pressing piston 18 is slidably fitted between the outer cylinder part 19 and the inner cylinder part 20, and the pressing piston 18 and the differential case 1
0, a hydraulic chamber 23 is defined between the two. In addition, the inner cylinder part 2
A spring 25 is interposed between the member 24 and the pressing piston 18, and the spring force of the spring 25 causes the pressing piston 18 to move to the first and second clutches. The plates 16, 17 are spring-biased towards the side that releases the frictional engagement. Furthermore, a disc spring 26 is interposed between the pressing piston 18 and the first clutch plate 16 closest to the piston 18.

On the other hand, a disc member 2T is fitted and fixed to the differential case 10 on the opposite side from the differential limiting clutch 15, and a gear pump 28 is provided between the disc member 27 and the differential case 10. A hydraulic circuit 29 connecting the hydraulic chamber 23 and the gear pump 28 is provided.

Referring also to FIG. 6, a circular pump chamber 30 is defined between the differential case 10 and the disc member 27, and an internal gear 31 is provided on the inner surface of the pump chamber 30 over the entire circumference. A gear pump 28 is constituted by a gear 32 that meshes with the internal gear 31 and is rotatably arranged at an eccentric position within the pump chamber 30. Furthermore, the gear 32 is fixed to a rotating shaft 33 that is rotatably supported by the differential case 1o and the disc member 27.
A driven gear 34 is integrally provided at the protruding end. Further, a drive gear 35 is integrally provided on the side gear 12r, and this drive gear 35 is connected to the driven gear 34.
mesh with.

In such a gear pump 28, two relatively rotatable transmission members in the differential device 4, that is, the differential case 1
0 and side gear 12r, gear 3
2 rotates while meshing with the internal gear 31, and the pump is operated.

The hydraulic circuit 29 includes a hydraulic storage chamber 36 provided between the differential case 10 and the disk member 27, a first flow direction regulating circuit 37, a second flow direction regulating circuit 3B, and a control mechanism 39.

A piston 40 is slidably connected to the hydraulic storage chamber 36.
This movement of the piston 40 causes the volume of the hydraulic reservoir chamber 36 to change.

The differential case 10 has a pair of communication ports 41.4 that function as an intake port or a discharge port depending on the direction of rotation of the gear 320.
2 is provided in communication with the pump chamber 30. The first flow direction regulating circuit 3T is provided to allow the flow of hydraulic oil only to these flow ports 41 and 42, and includes check valves 43a and 43b that are individually connected to both flow ports 41t and 42.
It is constructed by connecting in parallel. This first flow direction regulating circuit 37 is connected to the hydraulic pressure storage chamber 36 .

Further, the second flow direction regulating circuit 38 includes both the flow ports 41
．． It may be provided to only allow the flow of hydraulic oil from the flow ports 41 and 42, and is constructed by connecting check valves 44a and 44h, which are individually connected to both flow ports 41 and 42, in parallel.

The control mechanism 39 controls the second flow direction regulating circuit 38 and the hydraulic chamber 2.
3, and a throttle 46 and a relief valve 47 are connected in parallel between the oil passage 45 and the oil pressure storage chamber 36. I.J.
The IJ-F valve 47 is constructed by biasing a valve body 48 with a spring 49 so as to open when the working oil pressure of the oil passage 45 exceeds a certain value, and the relief valve 47 is configured such that the valve body 48 is biased by a spring 49. The opening area also increases as the working oil pressure of the oil passage 45 increases.

Next, to explain the operation of this embodiment, when a difference in rotational speed occurs between the left and right drive wheels F l r and F r r ,
The difference in rotation speed between the differential case 10 and the side gear 12τ is
The rotation speed of the left and right differential is 1/2, and the gear 32 rotates relative to the differential case 10, so that the gear pump 2
8 pump operation is started. When rotated relative to this, one of the flow ports 41 becomes a suction port, the other flow port 42 becomes a discharge port, and the hydraulic oil discharged from the gear pump 28 flows through the throttle 46.

When the relative rotational speed of the gear 32 with respect to ξ1 is small, the amount of hydraulic oil discharged from the gear pump 28 is small, and the amount of hydraulic oil corresponding to the discharge amount flows through the throttle 46 to the hydraulic storage chamber 36.
Therefore, the oil pressure in the oil passage 45, that is, the oil pressure chamber 23, remains low, and the pressure piston 18 is urged by the spring 25 to be in the engagement friction release position, and the differential limiting clutch 15 is not in the engaged state. It remains unlocked.

In FIG. 7, when the differential rotation speed exceeds a certain value N1 determined by the opening area of the throttle 46, the flow resistance of the throttle 46 increases, and the hydraulic pressure of the oil passage 45, that is, the hydraulic pressure chamber 23 increases. However, the pressing piston 18 begins to move toward the frictional engagement position against the spring force of the spring 25, and as a result, the torque of the differential device 4 also increases. However, at this time, oil line 4
Since the relief valve 47 opens in response to the increase in the hydraulic pressure of No. 5, the torque increases only slightly, and the relief valve 47 opens in response to an increase in the discharge pressure as the differential rotation speed increases. As the opening area becomes larger, the oil pressure in the hydraulic chamber 23 also gradually increases, and the torque also gradually increases.

When the differential rotation speed further increases and exceeds a constant value N2 determined by the maximum opening area of the IJ-F valve 47, the first and second clutch plates 16, 17
frictionally engages, the differential function becomes disabled, and both axles 21, 2
r is almost directly connected.

In this way, conventionally the differential limiting function is exhibited when the differential rotation speed is small as shown by the broken line in FIG. 7, whereas according to the present invention, the differential rotation speed is at a constant value N1 The operation of the differential limiting clutch 15 can be started after the difference exceeds .

C6 Effects of the Invention As described above, according to the present invention, the pressing member is biased by a spring toward the position where the frictional engagement state is released, and a hydraulic chamber is provided on the side of the pressing member opposite to both clutch plates. , a pump configured to operate the pump according to the relative rotation of both transmission members, and the hydraulic chamber, which applies a spring biasing force to the pressing member when the relative rotation speed of both the transmission members exceeds a set value. Since the differential is connected via a control mechanism configured to supply the hydraulic pressure to the hydraulic chamber to move the differential toward the frictional engagement position against the The function is not limited, and the differential limiting function is activated after the set value is exceeded.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention applied to a straddle-type vehicle, and FIG. 1 is a plan view of the straddle-type vehicle, and FIG. 2 is a diagram showing the front drive wheel removed. 3 is a rear view of the same, FIG. 4 is a partial vertical enlarged plan view of the left and right drive wheels and their surrounding areas, FIG. 5 is a vertical sectional view of the differential gear, and FIG.
The figure is a system diagram showing the hydraulic system between the gear pump and the hydraulic chamber, and FIG. 7 is a characteristic diagram showing a comparison between the device of the present invention and the conventional device. 4... Differential device, 10... Differential case as a transmission member, 12r... Side gear as a transmission member, 15
... Differential limiting clutch, 18 ... Pressing piston as a pressing member, 23 ... Hydraulic chamber, 28 ... Gear pump, 39 ... Control mechanism Fig. 2 Fig. 3 Fig. 1

Claims (1)

[Claims] A plurality of first clutch plates spline-engaged with one of the transmission members, between two transmission members that can rotate relative to each other;
A plurality of second clutch plates are overlapped with the first clutch plates and spline-engaged with the other transmission member.
A differential in which a differential limiting clutch is interposed, which is made up of a clutch plate and a pressing member that is movable between a position where the clutch plates are pressed against each other to engage in frictional engagement and a position where the frictional engagement is released. In the differential gear with a limiting clutch, the pressing member is biased by a spring toward a position where the frictional engagement state is released, and a hydraulic chamber is provided on the opposite side of the pressing member from the both clutch plates. A pump configured to operate the pump according to the relative rotation of the transmission members and the hydraulic chamber are configured to cause the pressing member to resist the spring biasing force when the relative rotation speed of both the transmission members exceeds a set value. 1. A differential gear with a differential limiting clutch, characterized in that the differential gear is connected via a control mechanism configured to supply hydraulic pressure to the hydraulic chamber to move the clutch toward a frictional engagement position.