JPH02253033A - Differential gear - Google Patents

Abstract

PURPOSE:To enable the correct control of differential limiting force without being influenced by the abrasion coefficient change and the like of a clutch disc by detecting the relative displacement quantity between a plate holder and a differential case variable according to the actual fastening quantity of a friction clutch. CONSTITUTION:A rotational position sensor 67 for detecting the relative rotation (relative displacement) between a case 17 and a plate holder 39 is fitted at a differential case 17, and the signal of the sensor 67 is inputted into a controller 69. The controller 60 is previously stored with the fastening force of a multiple disc clutch 43 and the strength of a spring 41 for supporting the plate holder 39, that is, the relation of the relative rotational quantity between the differential case 17 and the plate holder 30 against the fastening force, the fastening force of the multiple disc clutch 43 corresponding to the relative rotational quantity can be obtained on the basis of the input signals of the sensor 67. In addition, the controller 69 is formed in such a way as to provide the appropriate fastening force to the multiple disc clutch 43 according to the road surface condition, steering condition, especially the differential rotating speed between rear wheels, and the like.

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) A differential limiting device is described in Japanese Unexamined Patent Publication No. 61-67629. This device is configured to control the engagement force of a differential limiting multi-disc clutch of a differential device by detecting the pressure of an oil passage of a hydraulic actuator. In this way, since the tightening force is controlled based on the assumption that the hydraulic pressure and the tightening force are uniquely related, for example, even if the hydraulic pressure is the same, the tightening force may change due to a change in the friction coefficient (μ) of the clutch plate or a failure of the hydraulic actuator. Correct control may not be possible due to inability to respond to changes in force.

(Problems to be Solved by the Invention) Therefore, an object of the present invention is to provide a differential device that can correctly control the differential limiting force without being affected by changes in μ of the clutch plates.

[Structure of the Invention] (Means for Solving the Problem) The differential device of the present invention includes a differential case that rotates by inputting torque, a pinion shaft that rotates integrally with the differential case, and a pinion shaft that is rotatably supported by the pinion shaft. a pinion gear, a pair of side gears meshing with the pinion gear, a plate holder disposed to be rotatable relative to the differential case, an elastic body disposed between the differential case and the plate holder and generating an elastic force in the rotational direction, and the differential case. A sensor that detects the amount of relative displacement of the plate holder, a friction clutch disposed between the plate holder and the side gear, a means for engaging the friction clutch, and a signal from the sensor that applies the engaging force of the friction clutch through the engaging means. The invention is characterized by comprising a controller for controlling the apparatus.

(Operation) Rotation of the differential case is differentially distributed to each side gear via the pinion shaft and pinion gear due to the rotation of the pinion gear.

When the friction clutch is engaged by the engagement means, a differential limiting force is generated between the differential case and the side gears, that is, between each side gear through the elastic body, compared to a state where differential movement is possible.
Torque transmitted to the side gear with greater rotational resistance increases.

The amount of relative displacement between the plate holder and the differential case changes in response to the actual engagement force of the friction clutch, and since the sensor detects this amount of displacement, the correct engagement force is always known, and therefore it can be controlled appropriately.

(Example) An example will be explained with reference to FIGS. 1 to 3. As shown in FIG. 3, this embodiment is used in the power system of a two-wheel drive vehicle with a front engine and rear drive. This power system has a vertical engine 1 and a transmission 3.
, a propeller shaft 7, a rear differential 9 (a differential device in this embodiment used for the rear wheels), a rear axle 11, left and right rear wheels 13, left and right front wheels 15, and the like.

In addition, the left and right directions are the left and right directions in Figures 1 and 3,
The upper part of FIG. 1 corresponds to the front of the vehicle in FIG. 3 (the upper part of FIG. 3).

First, the configuration will be explained.

The differential case 17 is rotatably supported by the differential carrier 23 by thrust bearings 19, 2]. A ring gear 25 is fixed to the differential case 17, and the ring gear 25 meshes with a drive pinion gear on the propeller shaft 7 side. In this way, the differential case 17 is rotationally driven by the driving force from the engine 1.

A pinion shaft 29 is supported by the differential case 17,
A pinion gear 31 is rotatably supported on the pinion shaft 29. Pinion gear 31 has differential case 1
A pair of side gears 33 and 35 arranged coaxially with the gear 7 mesh with each other from the left and right sides.

The side gears 3B and 35 are provided with splines 37 for connecting with the left and right rear axles 11.

A plate holder 39 is rotatably arranged between the differential case 17 and the left side gear 33, and as shown in FIG. 2, the plate holder 39 is suspended from the differential case 17 via a spring 4 (an elastic body). ing.

Between the three plate holders and the left side gear 33, a plurality of clutch plates 38 and 40 arranged alternately are individually spline-engaged with these members 33 and 39 to form a multi-disc clutch 43 (friction clutch). has been done. When this multi-plate clutch 43 is engaged, the relative rotation between the differential case 17 and the left side gear 33 is restricted, and the differential movement between the left and right side gears 33 and 35 connected by the pinion gear 31 is restricted. The greater the engagement force of the multi-disc clutch 43, the greater this differential limiting force. When the multi-plate clutch 43 is released, the differential rotation of the side gears 33 and 35 becomes free.

The bushing rod 45 passes through the differential case 17 via suppression rings 47, 49 so as to be able to press the multi-disc clutch 43 between the bushing rod 45 and the differential case 17. A suppression ring 51 is arranged on the outer periphery of the right end side of the differential case 17 so as to be able to press the bushing rod 45 , and on the right side thereof, a pressing ring 53 is supported on the outer periphery side of the differential case 17 by a needle bearing 55 and suppressed via the needle bearing 57 . ring 5] is arranged so as to be able to suppress it. In this way, a transmission system for the pressing force of the multi-disc clutch 43 is configured. The operating arm 5 is swingably supported by the differential carrier 23, and a fork 6 provided at one end faces the press ring 53 so as to be able to abut on it, and the other end is connected to the shaft 65 of the fastening means 63.

The fastening means 63 consists of a motor, a speed reducer that amplifies its torque, and a gear mechanism that converts its rotation in the direction of the shaft 65. The motor of the fastening means 63 is connected to six controllers using a slip ring or the like. If the fastening means 63 or the operating arm 59 is pulled, this traction force will be applied to the operating arm 5.
The direction is converted into an axial pressing force by the two swings, and this pressing force engages the multi-disc clutch 43 via the above-mentioned transmission system. When the motor is reversed and the five operating arms are returned to their original positions, the multi-disc clutch 43 is released.

The differential case 17 includes the differential case 17 and the plate holder 3.
Rotational position sensor 6 that detects the relative rotation (relative displacement) of 9
7 is attached, and the signal from the sensor 67 is input to the controller 69. A slip ring or the like is used for electrical connection between the sensor 67 and the six controllers. Instead of the rotational position sensor 67, a position sensor 73 that detects the distance between the differential case 17 and the protrusion 71 of the plate holder 39 as shown in FIG. 2 may be used.

The controller 69 stores in advance the engagement force of the multi-disc clutch 43 and the strength of the spring 41 supporting the plate holder 39, that is, the relationship between the engagement force and the relative rotation amount of the differential case 17 and the plate holder 39. The fastening force of the multi-plate clutch 43 corresponding to the relative rotation amount is determined based on the input signal from the multi-plate clutch 43. Further, the controller 69 is configured to apply an appropriate engagement force to the multi-disc clutch 43 according to road surface conditions, steering conditions, particularly the differential rotation speed between the rear wheels 13, and the like.

When the multi-disc clutch 43 is strongly engaged during differential operation, the spring 41
A large torque is applied to the plate holder 39, which causes the differential case 17 and the plate holder 39 to rotate relative to each other. Furthermore, when the fastening force is weak, the deflection of the spring 41 is small and the amount of relative rotation is small. In this way, unlike conventional methods in which the tightening method is indirectly detected and controlled using hydraulic pressure, which is a substitute characteristic, since the actually generated tightening force is directly detected, errors are less likely to occur and proper control is possible. can be done.

Next, the functions will be explained using the vehicle shown in FIG. 3 as an example.

The rotational driving force from the engine 1 is transmitted from the differential case 17, two pinion shafts, pinion gear 31 to side gear 33.
, 35, the left and right rear wheels differentially distributed]-3 are rotationally driven.

When one of the rear wheels 13 slips on a rough road, the controller 69 uses the fastening means 63 to fasten the multi-disc clutch 43 with the necessary strength. Due to this differential limiting force of the rear differential 9, the driving force of the engine 1 is not concentrated only on the rear wheels 1-3 on the slip side, but is also transmitted to the other rear wheel 13, so that the vehicle does not get stuck and runs smoothly. It maintains smooth driving and escapes from bad roads. In this way, running performance is improved.

In addition, if the multi-disc clutch 43 is engaged in advance, when the vehicle body attempts to turn due to disturbances while driving on rough terrain, the rotation of the rear wheels 13 on the outer width side is suppressed by the differential limiting force of the rear differential 9, and the rotation of the rear wheels 13 on the outer width side is suppressed. The rotation of the rear wheels 13 on the side is encouraged, and a moment is generated that tries to return the vehicle body to its original posture. In this way, straight-line stability is improved.

When the multi-plate clutch 43 is released, the differential between the rear wheels 13 becomes free, allowing the vehicle to turn smoothly. In addition, by selecting the characteristics of the elastic body, stick-slip between the rear wheels 13 and the road surface or in the multi-disc clutch 43 during turning can be prevented, and the resulting vibration and noise can be prevented.

[Effects of the Invention] As described above, since the differential device of the present invention detects the displacement of the plate holder and the differential case due to the fastening force, unlike the conventional example, it is possible to prevent errors such as μ changes in the friction clutch and substitute characteristics. Freed from the influence, the differential limiting force can be properly controlled. In addition, the fastening force detection accuracy is high and the control response is good.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing one embodiment and peripheral members,] Figure 2 is a cross-sectional view showing the main parts of this embodiment, and Figure 3 is a power system of a vehicle using this embodiment. It is a skeleton mechanism diagram. 17... Differential case 29... Pinion shaft 31... Pinion gear 3
3.35... Side gear 39... Plate holder 41... Spring (elastic body) 67... Rotational position sensor (sensor) 43... Multi-plate clutch (friction clutch) 63... Fastening means 69 ... Controller agent Patent attorney Hidekazu Miyoshi 17 ... Differential case 29 ... Pinion gear shaft 31 / Pinion gear 3
3.35 Side gear 39...Plate holder 41...Spring (elastic body) 67...Rotational position sensor (sensor)

Claims (1)

[Claims] A differential case that rotates when torque is input, a pinion shaft that rotates integrally with the differential case, a pinion gear that is rotatably supported by the pinion shaft, a pair of side gears that mesh with the pinion gear, and are arranged to rotate freely relative to the differential case. an elastic body that is placed between the differential case and the plate holder and generates an elastic force in the rotational direction, a sensor that detects the amount of relative displacement between the differential case and the plate holder, and a sensor that is placed between the plate holder and the side gear. What is claimed is: 1. A differential device comprising: a friction clutch; a means for engaging the friction clutch; and a controller that controls the engaging force of the friction clutch via the engaging means based on a signal from a sensor.