JPS6167630A - Differential gear restricting apparatus - Google Patents

Abstract

PURPOSE:To prevent a one-side wheel lock and improve brake stability by installing a fluid pressure control means for improving the clutch tightening force on brake application, in a differential-gear restricting apparatus in which the tightening force of a frictional clutch is controlled according to the prescribed conditions. CONSTITUTION:As for a differential-gear mechanism, the side gears 8 and 8' in which the right and left driving shafts 9 and 9' are spline-connected are arranged oppositely in a differential gear case 3 rotatably supported through bearings 4 and 4' onto a housing 1 fixed onto a chassis side. Pressure rings 12 and 12' are arranged oppositely onto the outer peripheral part of these side gears 8 and 8', and multiple-disc type friction clutches 13 and 13' are installed between the rings 12 and 12' and the differential gear case 3, and is engaged and disengaged by a hydraulic piston 18. In this case, the pressurized-oil for increasing the clutch tightening force is introduced into the pressurized oil chamber 19 on one side of the hydraulic piston 18 during brake operation according to the output of a brake-operation deteceting means.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a differential limiting device that controls the engagement force of a friction clutch according to predetermined conditions.

(Prior Art) As a conventional differential limiting device, one shown in FIG. 6, for example, is known. "Nissan Skyline Service Bulletin No. 446 rSK-2", lθ, September 9, 1981
(Published by Nissan Motor Co., Ltd.) This conventional device is arranged between a pair of side gears 101 and 101' which are arranged facing each other inside a differential case 100 and are provided with left and right axle shafts. , Binion mate gear 1 meshing with side gears 101, 101'
02, a pressure ring 104, 104' which is disposed opposite to the outer periphery of the side gear 101, 101' and is cam-coupled to the end of the pinion mate shaft 103; 104' and the differential case lOO, and the side gear 101 and IOL'
and friction clutches 105, 105' for frictionally engaging the differential case 100 and the differential case 100.

Incidentally, the friction clutches 105, 105' include friction discs 106, 106' fixed to the side gears 101, 101', and a differential case 100.
Friction plate 107, 107' fixed on the side
Dishes friction plates IOA, IOA' with disc spring structure that provide initial torque to the clutch
It was composed of.

Therefore, the friction clutch 105.105 in the conventional device
' The clutch engagement force is generated by the initial torque from the dished friction plates 108, 108' and the pressure rings 104, 1 pushed open by the cam action.
This was due to the pressing force from 04', and looking at the transfer ratio characteristics, as shown in FIG. 7, the characteristic line A was a combination of the initial torque portion a and the pressing force due to the cam action.

(Problems to be Solved by the Invention) However, in such a conventional differential limiting device, the dished friction plates 108, 108'
The initial torque of The drive torque achieved is only the initial torque generated by the dished friction plates 108, 108' and does not reach the level of eliminating one-wheel lock, and the differential limiting device hardly contributes to braking stability or shortening the braking distance. There was a problem.

(Means for Solving the Problems) That is, the present invention was made with the purpose of solving the above-mentioned problems, and in order to achieve this purpose, in the present invention, a A friction clutch interposed in the friction clutch, a clutch engagement means provided on the friction clutch for applying a clutch engagement force by external fluid pressure, and a fluid pressure generation means connected to the clutch engagement means. In the differential limiting device, a brake signal from the brake operation detection means is input to the brake operation detection means for detecting a brake operation state and the fluid pressure generation means, and when the brake signal is input, the friction clutch outputs a fluid pressure control signal that increases the clutch engagement force. A fluid pressure control means is provided.

(Function) Therefore, in the differential limiting device of the present invention, the fluid pressure supplied from the fluid pressure generating means to the clutch engaging means in response to the fluid pressure control signal from the fluid pressure controlling means is controlled by the brake signal being input. , which increases when the brakes are applied.

This high fluid pressure increases the clutch engagement force of the friction clutch, increases the initial torque, promotes differential limiting action, and makes it possible to eliminate one-wheel lock when the brake is applied.

(Example) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In describing this embodiment, a differential limiting device for an automobile will be taken as an example.

First, the configuration of the embodiment shown in FIGS. 1 and 2 will be explained.

1 is a housing, and this housing 1 is supported by a stud port 2 on the vehicle body side.

3 is a differential case, which is rotatably supported with respect to the housing 1 by a tapered roller bearing 4.4'.

A ring gear 5 is fixed to the differential case 3. The ring gear 5 meshes with a pinion gear 7 provided on the propeller shaft 6, and the rotational driving force from the propeller shaft 6 is transmitted to the differential case 3. .

Reference numeral 8.8' denotes a side gear, which is disposed facing inside the differential case 3. The side gears 8, 8' include a left drive shaft 9 and a right drive shaft 9'.
are provided by spline connection.

A pinion mate shaft 10 is disposed between the site gears 8 and 8', and a pinion mate gear 11 that meshes with the side gears 8 and 8' is supported on the pinion mate shaft 10. There is.

Reference numeral 12.12' denotes a pressure ring, which is disposed opposite to the outer periphery of the side gears 8, 8'. This pressure ring 12.12' is fixed to the differential case 3 in one rotation direction, and It is provided so that it can be slid in the direction.

As shown in FIG. 2, this pressure ring 12, 12' has V-shaped grooves 12a, 12a' formed at opposing positions, and a V-shaped cam formed at the end of the pinion mate shaft 10. It is brought into contact engagement with the portion 10a.

Reference numerals 13 and 13' denote a friction clutch, which is interposed between the brake and jarrings 12, 12' and the differential case 3.
．． 13' is a multi-plate clutch structure, and includes a friction plate 13a fixed to the differential case 3;
13a', and friction discs 13b, 13b' fixed to the side gears 8, 8'.

Reaction plates 14 and 14' are arranged in contact with the outer surface of the friction clutch 13 and 13'.

15.15' is a needle bearing, which includes the reaction plate 14.14' and spacer 16.18.
' is interposed between the friction clutch 13 and
．． 13', the reaction force of the clutch engagement force of one f! l Friction clutch 13 side rear crayon plate 14. Needle bearing 15. Spacer 16. Butschrod 17.
and supported by the housing l via the hydraulic piston 18,
The other friction clutch 13' side includes a reaction plate 14', a needle bearing 15' and a spacer 1B.
' It is supported by the housing 1 via.

Reference numeral 18 denotes a hydraulic piston as a clutch fastening means, which is disposed in the housing 1 so as to be able to slide in the axial direction.A bush loft 17 is provided on one end surface of the hydraulic piston 18, and a bush loft 17 is provided on the other end surface. A pressure oil chamber 19 and a hydraulic boat 19' are provided.

20 is a hydraulic pressure generating device as a fluid pressure generating means,
It supplies hydraulic pressure to the hydraulic piston 18,
This hydraulic pressure generator 20 includes a motor 22 that drives a hydraulic pump 21, a pressure oil pipe 24 that supplies pressurized oil by the hydraulic pump 21 from a reserve tank 23 to a hydraulic boat 19', and A relief pipe when the pressure oil flowing through the provided check valve 25 and the pressure oil pipe 24 exceeds a predetermined pressure? Reserve tank 2 after 6
A relief valve 28 is provided on the branch pipe 29 of the pressure oil pipe 24 to switch between supplying pressurized oil to the hydraulic port 19' side or returning it to the reserve tank 27 to reduce the supply pressure. The structure includes a solenoid valve 30 that performs the operation.

31 is a hydraulic control means as a fluid pressure control means,
Inputs the brake signal (C) from the brake sensor 32 as a brake operation detection means.

When the brake signal (C) is input, hydraulic control signals (d) and (e) are outputted to increase the clutch engagement force of the friction clutches 13 and 13'.

33 is a pressure sensor as a pressure detection means, and the pressure oil pipe ? 4, the hydraulic pressure generator 20
detecting the pressure of pressurized oil supplied from the hydraulic boat 19' to the hydraulic boat 19', and outputting a hydraulic signal (f) to the hydraulic pressure control means 31;
It is used as an input signal when the hydraulic pressure control means 31 compares whether the actual hydraulic pressure is larger or smaller than the set hydraulic pressure at the time of brake operation.

The input/output signals to the hydraulic control means 31 are as shown in FIG. The output signals include hydraulic control signals (d), (e) for the motor 22 and the solenoid valve 30.
) is used.

Next, the operation of the embodiment will be explained.

(a) When driving with the brake inactive When the brake is inactive, the pinion mate shaft 10
The pressure ring 12.12' is pushed open to the left and right by the cam action of Transmits a torque greater than that transmitted to the electric wheel on the side that is connected. It exhibits what is called a normal differential limiting effect.

The transfer ratio characteristics in the brake non-operating state are as shown in diagram B in FIG. 4, and the straight running performance and driving force performance are improved.

(B) When the brake is activated When the brake is activated, the brake signal (e) is output from the brake sensor 32 to the hydraulic pressure control means 31, and this brake signal (C) causes the hydraulic pressure control means 31 to output the hydraulic pressure to the hydraulic pressure generator 20. By outputting the control signals (d) and (el), the hydraulic boat 19' and the pressure oil chamber 19 are
Pressurized oil is supplied, and with this pressurized oil, the hydraulic piston 18
It moves to the right in FIG. 1 and applies l4 clutch engagement force to the friction clutch 13, 13'.

This clutch engagement force generates a high initial torque, and even if one wheel tries to lock during braking, the driving force is transmitted to the wheel on the side trying to lock, preventing a one-wheel lock condition. .

Incidentally, the transfer ratio characteristic when the brake is applied is as shown in line C in FIG. 4.

Next, the flow of the operation of the hydraulic control means 31 when the brake is applied will be explained with reference to the flowchart shown in FIG. 5. First, in step 50, it is determined whether the brake is applied or not.

Then, if the brake is not in operation, the process directly proceeds to END, and if the brake is in effect, the process proceeds to the next step 51.

In step 51, the oil pressure signal (f
), it is determined whether the oil pressure in the pressure oil pipe 24 is above the set pressure, and if it is above the set pressure, proceed to step 52, turn on the solenoid valve 30 to maintain the pressure, and if it is below the set pressure, proceed to step 53. Then, turn on the motor 22 and solenoid valve 30 and increase the oil pressure to the set pressure.

Incidentally, when the brake pedal is released from the brake pedal to put the brake in a non-operating state, both the motor 22 and the solenoid valve 33 are turned off and released.

Although one embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and the present invention may be modified without departing from the gist of the present invention. included.

For example, although the differential limiting device of the embodiment is a device in which a clutch engagement force is generated by a cam action, a device without a cam action may be used.

Furthermore, although an embodiment has been shown in which no external hydraulic pressure is used when the brake is not activated, the clutch engagement force may be applied using external hydraulic pressure depending on the vehicle speed or the like.

In addition, the embodiment device is provided with a rotational deceleration detection child actor of the wheel or drive shaft to detect a state where the rotational deceleration is greater than a set value, that is, a so-called state immediately before wheel lock, and reduce the hydraulic pressure from the hydraulic pressure generating device. A device may be incorporated to prevent both wheels from locking.

(Effects of the Invention) As explained above, according to the differential limiting device of the present invention, the fluid pressure generating means is provided with a fluid pressure generating means that increases the clutch engagement force of the friction clutch when the brake is applied. Therefore, it is possible to prevent one-wheel locking when the brake is applied, and it is possible to achieve the effect of achieving braking stability and shortening the braking distance.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a differential limiting device according to an embodiment of the present invention, FIG. 2 is a view seen from the arrow Z direction in FIG. 1, and FIG. 3 is a control block in the hydraulic control means of the individual device/equipment. Figure 4 is a transfer ratio characteristic diagram of the embodiment device,
Fig. 5 is a flowchart showing the flow of operation in the hydraulic control means of the embodiment device, Fig. 6 is a sectional view showing a conventional differential limiting device, and Fig. 7 is a transfer ratio characteristic diagram in the conventional device. . 3...Differential case 8.8'...Side gear 13.13'...Friction clutch 18...Hydraulic piston (clutch engagement means) 20...
- Hydraulic pressure generator (fluid pressure generation means) 31... Hydraulic pressure control means (fluid pressure control means) 32... Brake sensor (brake operation detection means) C... Brake signal

Claims (1)

[Claims] 1) A friction clutch interposed between the differential case and the side gear, and a friction clutch provided in the friction clutch,
Brake operation detection means for detecting a brake operation state in a differential limiting device comprising a clutch engagement means for applying a clutch engagement force by external fluid pressure, and a fluid pressure generation means connected to the clutch engagement means. and a fluid pressure generator that inputs a brake signal from the brake operation detection means to the fluid pressure generation means, and outputs a fluid pressure control signal that increases the clutch engagement force of the friction clutch when the brake signal is input. A differential limiting device comprising a control means.