JPH03265745A - Differential device - Google Patents

Abstract

PURPOSE:To obtain a differential control force responding to the rotation difference by carrying out the differential control by a viscous coupling through a friction clutch, and composing the system to suppress the connecting force of the clutch responding to the input torque to a differential mechanism. CONSTITUTION:When the torque from an engine is input to a differential mechanism 39, a pinion gear 33 is moved to the left side together with a shaft 31 by a thrust from the gearing with a right side gear 37, a left side gear 35 is moved to the left side by this moving force and a thrust force gearing with the gear 33 is addition, and a multiphase clutch 65 is pressed by a side wall 71 and connected. The connecting force of the clutch 65 by the pressing force of a pressing means 97 is made smaller when the input torque from the engine is smaller, and made larger as the input torque is increased. When the connecting force of the clutch 65 is small, the differential control force of a viscous coupling 41 is made to be smaller responding to its slippage. And as the connecting force of the clutch 65 is made to be larger and the slippage is made smaller, the differential control force is made larger. And when it is connected solidly, a normal differential control force can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a differential device used in a vehicle or the like.

(Prior art) As a conventional differential device, for example,
There are those described in Japanese Utility Model Publication No. 1.08857 and Japanese Utility Model Application Publication No. 104731/1983. The former is a differential device that limits differential differential by the engagement force of a multi-disc clutch.
The latter is a differential device that limits differential movement using a viscous coupling.

(Problem to be Solved by the Invention) However, the former cannot obtain differential limiting characteristics according to the rotational difference as the latter. Further, for example, when the vehicle is accelerating, a large engagement force is applied to the multi-disc clutch in order to increase the differential limiting force and prevent the wheels from spinning. If the friction plates of the multi-disc clutch slip in this condition, a loud squeaking sound will be generated.

In addition, in the latter case, for example, when one wheel locks during sudden braking, the rotational difference between it and the other wheel increases, and the locking force of one wheel is transmitted to the other wheel due to the large differential limiting force in the viscous coupling. There is a risk that the function of the anti-lock braking system (ABS), which optimally controls the braking force of each wheel to prevent all four wheels from locking at the same time, may be impaired.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a differential device that can obtain a differential limiting force corresponding to the rotational difference, and also control the differential limiting force to be small when the input torque is small, thereby suppressing the generation of abnormal noise. .

[Structure of the Invention] (Means for Solving the Problems) A differential device of the present invention includes a differential mechanism, a pressing means that converts input torque to the differential mechanism into a pressing force corresponding to the magnitude of the differential mechanism, The present invention is characterized in that it includes a friction clutch that is engaged by this pressing force, and a viscous coupling that is arranged between differentially rotating members of the differential mechanism to limit differential movement via the friction clutch.

(Function) When the input torque is small, the engagement force of the friction clutch by the pressing means is small, and therefore, the differential limiting force becomes small due to slipping of this clutch portion.

Furthermore, as the input torque increases, the engagement force of the friction clutch increases accordingly, and the differential is limited by the viscous coupling. In this case, if the pressing force is large and a differential force is applied that causes the friction clutch to slip when it is strongly engaged, the viscous coupling causes slippage, so no squeaking noise is generated due to the slippage of the friction clutch.

(Example) One embodiment will be explained with reference to FIGS. 1 and 2.

FIG. 2 shows the power system of a vehicle using this embodiment.

Hereinafter, the left-right direction of the vehicle is the left-right direction in FIG. 1(a), and the upper side corresponds to the front of the vehicle (the upper side in FIG. 2).

First, the configuration of the power system shown in FIG. 2 will be explained.

This power system includes an engine 1, a transmission 3, a propeller shaft 5, a rear differential 7 (a differential device in this embodiment placed on the rear wheel side), rear axles 9 and 11,
It consists of left and right rear wheels 13.15, left and right front wheels 17.19, etc. This vehicle is also equipped with ABS.

Next, the rear differential 7 will be explained with reference to FIGS. 1 and 2.

A differential case 21 of the rear differential 7 is rotatably supported within a differential carrier 23. A ring gear 25 is fixed to the differential case 21, and this gear 25 is connected to the propeller shaft 5.
It meshes with a drive pinion gear 29 provided at the rear end of the drive pinion shaft 27 on the side. In this way, the differential case 21 is rotationally driven by the driving force from the engine 1.

A pinion shaft 31 is engaged with the groove 30 of the differential case 21 so as to be movable in the axial direction, and a pinion gear 33 is rotatably supported on the shaft 3. A spherical washer 34 is arranged between the gear 33 and the differential case 21. Left and right side gears 35 and 37 mesh with the gear 33.

In this way, the differential mechanism 39 is configured. The rotation of the differential case 21 is dividedly outputted from the shaft 31 to the left and right gears 35.37 via the gear 33.
The rotation of the gear 33 differentially distributes the power to the left and right sides according to the difference in drive resistance on the 7 sides.

A viscous coupling 41 for limiting differential movement is arranged on the left side of the differential mechanism 39. This viscous coupling 4
The housing 43 of No. 1 and the /% bulb 45 are arranged so as to be relatively rotatable. The housing 43 and the hub 45 are each provided with spline portions 47 and 49. The left rear axle 9 is connected to the housing 43 by a spline 47. Further, the right rear axle 11 is connected to the hub 45 by a spline 49, and is also connected to the right side gear 37 by a spline 51.

Housing 43. A working chamber 53 is provided between the hubs 45 and is filled with viscous fluid (highly viscous silicone oil). Housing 43. There is an X ring 55 between the hubs 45.
55 (Seal with X-shaped cross section) and backup ring 5
7.57 is placed to keep the working chamber 53 tightly closed at night.

As shown in the enlarged view in Figure 1(b), now
Friction plates 59 are connected to the inner periphery of the friction plates 59 so as to be movable in the axial direction by splines 61, and an outer plate 63 is disposed between each friction plate 59, forming a multi-plate clutch 65 (friction clutch). . An inner plate 67 is arranged between each outer plate 63, and this inner plate 67 is connected to six splines on the outer periphery of the hub 45 so as to be freely movable in the axial direction. Right side wall 7 of housing 43
] is formed integrally with the left side gear 35, and is connected to the cylindrical portion 73 of the housing 43 by splines 61, 72 so as to be movable in the axial direction. An O-ring 75 is disposed between the side wall 71 and the cylindrical portion 73, and a retaining ring 77 is attached to the cylindrical portion 73. In this way, the viscous coupling 41 is constructed.

When the multi-plate clutch 65 is engaged and the outer plate 63 is connected to the housing 43, the differential motion between the housing 43 and the hub 45 is limited by the shear resistance of the silicone oil between the plates 63 and 67, and the Therefore, the differential movement between the left and right rear wheels 13.15 is limited. This differential limiting force increases as the differential between the rear wheels increases.

When torque from the engine 1 is input to the differential mechanism 39,
The pinion gear 33 moves to the left together with the shaft 3 due to the thrust force of meshing with the right side gear 37, and the left side gear 35 moves to the left due to the thrust force of meshing with the gear 33 in addition to this moving force. 71 to press and engage the multi-disc clutch 65. In this way, the differential mechanism 3
9 constitutes a pressing means 79.

The engagement force of the multi-disc clutch 65 due to the pressing force of the seven pressing means is small when the input torque from the engine l is small.
It increases as the input torque increases. Multi-plate clutch 6
When the fastening force of the viscous coupling 41 is small, the differential limiting force of the viscous coupling 41 becomes small in accordance with the slippage. Multi-plate clutch 6
5. Sliding when the fastening force is small does not generate a squeaking sound. Further, as the engagement force of the multi-disc clutch 65 increases and slippage decreases, the differential limiting force increases, and when the multi-disc clutch 65 is firmly engaged, a normal differential limiting force is obtained. Multi-plate clutch 65
Since the differential when the fastening force is large is absorbed between the plates 63 and 67, no slipping occurs in the clutch 65 and no squeaking noise occurs.

In this way, the rear differential 7 is configured.

Next, the function of the rear differential 7 will be explained based on the power performance of the vehicle shown in FIG.

The driving force of the engine 1 is shifted by the transmission 3, transmitted to the rear differential 7 via the propeller shaft 5, and dividedly output to the left and right rear wheels 13.15, and the differential is limited according to the magnitude of the engine torque. .

Therefore, when starting or accelerating, a large differential limiting force is obtained and straight-line performance is improved. When turning, the input torque is relatively small, and smooth turning is possible due to the slippage of the multi-disc clutch 65 and the differential tolerance between 6, 3, and 67 depending on the magnitude of the engine torque. When braking, the accelerator pedal is released and the input torque is reduced, and the left and right rear wheels 13.15 have free differential differential, so the ABS function is not inhibited and the braking force of each wheel is optimally controlled, making it safe and effective. Braking is possible.

Note that the multi-plate clutch 65 may be provided between the hub 45 and the inner plate 67, or may be provided on both. Further, the pressing means does not depend on the meshing thrust force of the gears as described above, but other mechanisms may be provided.

[Effects of the Invention] The differential device of the present invention is configured such that the differential is limited by a viscous coupling via a friction clutch, and the engagement force of this clutch is controlled in accordance with the input torque to the differential mechanism. Therefore, a differential limiting force corresponding to the rotational difference can be obtained, and when the input torque is small, this differential limiting force can be made small. Furthermore, the generation of squeaking noise in the clutch section can be suppressed.

[Brief explanation of drawings]

FIG. 1(a) is a sectional view of one embodiment, and FIG. 1(1)) is a sectional view of an embodiment.
) is an enlarged view of the main parts, and FIG. 2 is a skeleton mechanism diagram showing the power system of a vehicle using this embodiment. 39... Differential mechanism 41... Viscous coupling 65... Multi-plate clutch (friction clutch) 79... Pressing means

Claims (1)

[Claims] A differential mechanism, a pressing means that converts the input torque to the differential mechanism into a pressing force corresponding to the magnitude of the torque, a friction clutch that is engaged by this pressing force, and a friction clutch that connects the differential mechanism through the friction clutch. A differential device comprising: a viscous coupling disposed between differentially rotating members for limiting differential movement.