JPH0649957Y2 - Differential limiting mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a differential limiting mechanism assembled in a differential device.

(Prior Art) The differential limiting mechanism increases the transmission torque of the output shaft on the low-speed rotation side when the differential gear of the differential gear operates to prevent deterioration of running performance. Part 5
31 to 33 (published by the Society of Automotive Engineers of Japan), "Automotive Engineering Complete Book (9), pages 324 to 325 (published by Sankaido)", etc., for example, bevel gear type differential A differential limiting torque for limiting the differential between both output shafts is obtained by engaging the friction clutch disposed in the differential device by the component force in the thrust direction of the force transmitted between the pinion gear and the side gear that constitute the device. Is.

(Problems to be solved by the invention) By the way, in such a differential limiting mechanism, the component force of the cam and the gear is used as the engaging means of the friction clutch, and the constituent elements of the mechanism are rigid bodies. Momentary torque fluctuations due to manufacturing precision such as backlash of members constituting the power transmission path of the dynamic device affect the clutch engagement state, causing stick-slip in the friction clutch.
In particular, when the engaging force of the friction clutch is set to be large in order to increase the torque ratio between the high and low speed axles, a violent stick-slip occurs, which causes vibration and chatter noise. If such a stick-slip occurs, the driver feels uncomfortable and anxious, the durability of the differential limiting mechanism itself is affected, and a desired torque ratio cannot be obtained, resulting in deterioration of driving performance. It may not be able to be prevented sufficiently.

A differential limiting mechanism that should address these problems is published in "Nikkei Mechanical (1986, 11) No. 17, pp. 27-28".
Is shown in. In such a differential limiting mechanism, a worm gear is adopted to mechanically extract the thrust force and utilize it as the engaging force of the friction clutch.
The gear meshing ratio is increased to reduce torque fluctuations. However, in such a differential limiting mechanism, the structure is complicated, and the friction on the tooth surface of the gear is large, so that the size is increased and the cost is increased to secure the strength.

Therefore, the object of the present invention is to solve all of these problems.

(Means for Solving the Problem) The present invention is a differential limiting mechanism for limiting the differential between two output means connected to one input means via a differential mechanism. The pressing force generating means which is arranged at the connecting portion of the power transmission system path leading to each output means and which deforms according to the transmission torque to generate the pressing force, and the pressing force of the pressing force generating means actuates the input. The means and the friction means for limiting the differential between the two means of the both output means are provided.

(Operation and effect of device) In such a configuration, since the pressing force generating means is variable with respect to the torque, the pressing force generating means has the ability to absorb an instantaneous torque fluctuation, and the occurrence of stick slip in the friction engagement means. Is prevented. Therefore, the torque ratio between the high and low speed output means can be set large, the traveling performance of the vehicle can be improved, and the transmission torque can be directly used for the friction engagement force, so that a large torque ratio can be obtained. With a small number of parts and a simple structure, the mechanism can be downsized,
The cost can be reduced.

(Embodiment) The first embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows a bevel gear type differential device 10 having a differential limiting mechanism according to a first embodiment of the present invention. The differential device 10
In, the differential case 11 (hereinafter referred to as the differential case) is provided with a ring gear 12 on the outward flange portion,
In addition, the case 11 includes a plurality of pinion gears 13, a pair of side gears 14, and a pressing force generating means 10 forming a differential limiting mechanism.
a and frictional engagement means 10b are housed.

The differential case 11 corresponds to the input means of the present invention, and the pinion gear 13 is provided inside the case 11.
It is assembled through. The pinion gear 13 is rotatably supported by the pinion shaft 13a and meshes with both side gears 14. Each side gear 14 is a pressing force generating means.
It is connected to each side gear shaft 17 via a cell holder 15 and cells 16A and 16B which form 10a. Each side gear shaft 17 corresponds to each output means of the present invention.

As shown in FIGS. 1 to 3, the pressing force generating means 10a is composed of a cell holder 15 and a large number of cells 16A and 16B. The cell holder 15 is provided with a plurality of ribs 15b provided at equal intervals on the inner circumference of the stepped tubular portion 15a, and each rib 15b is a tubular portion 15a.
A predetermined length in the radial direction. Further, a large number of tooth portions extending in the axial direction are formed at each end of the tubular portion 15a. On the other hand, the inner end portion of the side gear shaft 17 is formed to have a small diameter, and a plurality of ribs 17b provided at equal intervals are provided on the outer circumference of the small diameter portion 17a. The cell holder 15 is fitted to the outer circumference of the small diameter portion 17a, and the cells 16A and 16B in which a plurality of storage chambers are formed between the ribs 15b of the holder 15 and the ribs 17b of the side gear shaft 17 are A non-compressed fluid 16b is enclosed in a bag body 16a made of an elastomer such as rubber and is housed in each housing chamber. The cell holder 15 is integrally rotatably fitted to the side gear 14 at the outer end side tooth portion of the tubular portion 15a.

The friction engagement means 10b is composed of two friction plates 18a, 18b, and a large number of radially extending teeth are formed on the outer circumference of each friction plate 18a, 18b. It meshes with the inner end side tooth portion of the tubular portion 15a. In this state, the friction plates 18a and 18b are opposed to each other with a minute gap therebetween and are in contact with the inner ends of the cells 16A and 16B.

In the differential gear 10 having such a configuration, the power input from the ring gear 12 to the pinion shaft 13a via the differential case 11 is distributed from the pinion gear 13 to each side gear 14,
Each side gear 14 is rotated. When the cell holder 15 is rotated in the direction of arrow A in FIG. 2 by the rotation of the side gear 14, each rib 15b of the holder 15 presses the first cell 16A as shown in FIG. The shaft 17 is rotated, and both wheels connected to each side gear shaft 17 so as to be able to transmit power are rotated. When the cell holder 15 rotates in the direction of arrow B in FIG. 2, the second cell 16B is pressed to rotate the side gear shaft 17.

During this period, one of the cells 16A and 16B is deformed according to the pressing force, and if the representative dimension of the cell width before pressing the cell is l and the axial length of the cell is L, the cell width is 1- The cell length of Δl becomes L + ΔL, and both friction plates 18a, 18b
Frictionally engages with the above pressing force, that is, the pressing force corresponding to the transmission torque, and when differential rotation occurs between both side shafts 17, a differential limiting torque proportional to the transmission torque is generated. In this case, since each cell 16A, 16B has a damper function, it absorbs a stick-slip occurrence factor such as an instantaneous fluctuation of the transmission torque. As a result, the occurrence of stick slip can be prevented, and the torque ratio between the high and low speed side gear shafts 17 can be set to a large value, so that the running performance of the vehicle can be sufficiently improved. In addition, the transmission torque from the side gear 14 to the side gear shaft 17 is transmitted to each cell 16A, 1
Since 6B can be used accurately as an engaging force for both friction plates 18a, 18b, a large torque ratio can be obtained with a small number of parts and a simple structure. As a result, it is possible to reduce the size and cost of the differential device.

4 and 5 show two modified examples of the differential limiting mechanism according to the first embodiment. The differential limiting mechanism of the first modified example shown in FIG. 4 is provided with both friction plates 18a and 18b constituting the pressing force generating means 10a and the friction engagement means 10b, and also with a pair of second friction plates 18c and 18d. ing.
Each of the second friction plates 18c and 18d is interposed between the side wall of the differential case 11 and the back of the side gear 14, and each of the cells 16A and 16B.
A differential limiting torque is generated between the differential case 11 and the side gear 14 by the reaction force at the time of pressing. The differential limiting mechanism of the second modification shown in FIG. 5 is an example in which the second friction plates 18c, 18d of the first modification are replaced by cone clutches 18e, 18f.

FIG. 6 shows a differential limiting mechanism according to the second embodiment, and 2 of the same mechanism.
The differential device including the differential limiting mechanism according to one modified example is shown by a skeleton.

The differential gear shown in FIG. 6 (a) is a planetary gear type differential gear 20, which is provided with a carrier 24 that supports a sun gear 21, a ring gear 22 and a planetary gear 23. The ring gear 22 input, the sun gear 21 and the carrier 24 Is configured on the output. Thus, in the differential device 20, the pressing force generating means 20a is arranged on the carrier 24 side, and the friction engagement means 20b is arranged between the carrier 24 and the sun gear 21. Both of these means 20a, 20b are structurally similar to both means 10a, 10b of the first embodiment and function to limit the differential between the sun gear 21 and the carrier 24.

In the first modification shown in FIG. 6 (b), the pressing force generating means 20a is arranged on the sun gear 21 side, and the friction engagement means 20b is arranged between the sun gear 21 and the ring gear 22. The differential between these two output elements 21, 22 is limited. Further, in the second modification shown in FIG. 6C, the pressing force generating means 20a is arranged on the ring gear 22 side, and the friction engagement means 20b is arranged between the ring gear 22 and the carrier 24. Thus, the operation between the two output elements 22 and 24, which are both output elements, is limited.

[Brief description of drawings]

FIG. 1 is a sectional view of a bevel gear type differential device having a differential limiting mechanism according to the first embodiment of the present invention, and FIG. 2 is an arrow II in FIG.
-II is an enlarged sectional view taken along the line II, FIG. 3 is a sectional view corresponding to FIG. 2 showing the operating state of the pressing force generating means, and FIG. 4 is a first modification of the differential limiting mechanism of the first embodiment. FIG. 5 is a partial sectional view of a differential device, FIG. 5 is a sectional view corresponding to FIG. 4 showing a second modification, and FIG. 6 (a) shows a differential limiting mechanism according to a second embodiment of the present invention. A skeleton diagram of the provided planetary gear type differential device, the same figure (b) is a skeleton diagram of the differential device showing a first modification of the differential limiting mechanism of the second embodiment, and the same figure (c) is the second modification. It is a skeleton diagram corresponding to the same figure (b) showing an example. Explanation of symbols 10, 20 ... Differential device, 10a, 20a ... Pressing force generating means, 10
b, 20b ... friction engagement means, 11 ... differential case (input means), 15 ... cell holder, 16A, 16B ... cell, 17 ... side gear shaft (output means), 18a-18d ... friction plates , 18e, 18f …… Cone clutch, 21 …… Sun gear,
22 …… Ring gear, 24 …… Carrier.

Claims (1)

[Scope of utility model registration request] 1. A differential limiting mechanism for limiting differential between two output means connected to one input means via a differential mechanism, and a power transmission system from the input means to each output means. A pressing force generating unit that is disposed at the connecting portion of the passage and deforms in accordance with the transmission torque to generate a pressing force, and a pressing force of the pressing force generating unit that operates by the pressing force of the pressing force generating unit. A differential limiting mechanism comprising friction engagement means for limiting the differential between the two means.