JPH0226321A - Power transmission - Google Patents

Abstract

PURPOSE:To prevent any deformation and damage from occurring as thinning wall thickness or the like of each peripheral member by installing a fuse means, which acts when pressing force of an actuator exceeds the specified value, and thereby regulates a rise in this pressing force, in a power transmission. CONSTITUTION:A piston member 81 is made contact with a pressing member 93 via a needle bearing 91, attaching a push rod 95 solidly to this pressing member 93, and this push rod 95 is halved left and right, then a fuse member 99 is interposed between these halved rods. Each of contact surfaces 103, 105 is installed in a case body 37 and the pressing member 93, and a fuse means is constituted of these contact surfaces 103, 105 and the fuse member 99. With this constitution, even if pressing force of actuators 89, 119 exceeds the specified value and thereby goes up, excessive pressing force will not act on a friction clutch, so that any deformation and damage are preventable as thinning wall thickness or the like of each peripheral member.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention 1 (Field of Industrial Application) This invention relates to a power transmission device using a multi-disc friction clutch.

(Prior Art) Japanese Patent Publication No. 57-4536 describes a differential device using the above-described power transmission device as a differential ill-limiting mechanism. A differential device constructed similarly to this device is shown in FIG. 4, and its construction will be briefly described.

A drive pinion gear V2 is attached to the rear end of the drive pinion shaft 201, which rotates by rotational driving force from the engine.
The differential case 205 is rotatably supported by the differential carrier 211 by bearings 207 and 209, and meshes with the drive pinion gear 203 and rotates together with the ring gear 213. This rotation is caused by the pinion shaft 21 fixed to the differential case 205.
5 is distributed to left and right side gears 219 and 221, which rotate by meshing with the pinion gear 217. These side gears 219 and 221 are connected to shafts that transmit power to the left and right wheels. Moreover, the differential limiting mechanism is the differential case 20.
5 and one of the side gears 219, the multi-disc friction clutch 223 is operated by a hydraulic v-controlled actuator 2.
25 is pressed and fastened via a pushing force transmission system consisting of a bushing rod 227, etc., and the fastening force is adjusted to connect the side gears 219 and 221.
It is configured to limit the differential rotation between the two and to adjust the amount of the limit.

By the way, in such a configuration, for example, in the case of a two-wheel drive vehicle (2WD>), if one of the left and right wheels slips, the same driving force does not flow to the other wheel, so the vehicle loses driving force. To avoid this, hydraulic pressure is supplied to the actuator 225, the friction clutch 223 is engaged, and driving force is transmitted to the other wheel.At this time, if a large hydraulic pressure exceeding a predetermined value is applied to the actuator 225, If supplied, the engagement force of the friction clutch will become excessive, and the load will be concentrated on the wheel on the anti-slip side, potentially damaging this axle.

Further, the differential case 205 is deformed by the pressing force of the actuator 225, and the differential carrier 211 is further deformed by the pressing force transmitted through the bearings 207 and 209, and the pinion gear 217, side gear 219, 221, drive pinion gear 203, and ring gear of the differential device are deformed. 213 may deteriorate, causing noise or damage to these gears. Therefore, conventionally, devices have been constructed with strength that takes these into consideration, but this has resulted in problems such as increased weight.

(Problems to be Solved by the Invention) Therefore, in the power transmission device of the present invention, even if the pressing force of the actuator increases beyond a predetermined value, an excessive pressing force does not act on the agw I clutch, so that the The purpose of the present invention is to provide a power transmission device that does not cause deformation or damage even though its thickness is reduced.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the power transmission device of the present invention includes first and second rotating members arranged coaxially so as to be relatively rotatable; A plurality of a! sheets are alternately arranged and engaged with the first and second rotating members, respectively. A power transmission device comprising a friction clutch made of a friction plate and an actuator that can be pressed to engage the friction clutch, and the actuator acts when the pressing force of the actuator exceeds a predetermined value to prevent an increase in the pressing force. and fuse means for regulating.

(Operation) When the S* clutch is engaged by the operation of the actuator, the first and second rotating members are connected, torque is transmitted from one to the other, and the friction clutch slips in accordance with the engagement force, causing these rotating members to Differential rotation between is limited or allowed.

When the pressing force of the actuator exceeds a predetermined value when the friction clutch is engaged, the fuse means acts to restrict the increase in the pressing force acting on the friction clutch.

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

Figure 2 shows an example in which this embodiment is used as a differential limiting mechanism for a differential device (rear differential) installed between the rear axles, which are the driving side axles, in a 2WD vehicle with a front engine and rear drive (FR). . In the following description, the directions are those shown in FIG. 1, and for the vehicle shown in FIG. 2, the left-right direction in FIG. 1 corresponds to the vehicle width direction, and the upper direction corresponds to the front direction.

First, the power transmission of this vehicle will be explained with reference to FIG.

The rotational driving force of the engine 1 is shifted by a transmission 3, transmitted to a rear differential 11 via a propeller shaft 7, and distributed by the rear differential 11 to left and right rear wheels 17.19 via a rear axle 13.15. Front wheel 21.21
performs steering.

Next, the configuration of this embodiment will be explained.

The drive and nion shaft 23 is connected to the propeller shaft 7 and rotatably supported by the differential carrier 31 via bearings 25, 27, and 29. A drive pinion gear 33 is integrally formed at the rear end of the drive pinion shaft 23.

The differential case 35 (first rotating member) is formed by fixing a case body 37 and a cover 39 together with bolts 41, and is rotatably supported by the differential carrier 31 by bearings 43, 45. A ring gear 47 that meshes with the drive pinion gear 33 is fixed to the differential case 35 by bolts 49.

In this way, the differential case 35 is rotationally driven by the rotational driving force from the engine 1.

A binion shaft 51 is fixed to the differential case 35,
A pinion gear 53 is rotatably supported on the pinion shaft 51. Side gears 55 and 57 arranged on the left and right sides mesh with the pinion gear 53, respectively. In this way, the differential device 59 is configured.

One side gear 55 (on the left in the figure) becomes a second rotating member as described later, and is rotatably fitted into a shaft support 61 provided between the cover 39 of the differential case 35 and the other (left side gear 55).
The side gear 57 (cloth in the figure) is rotatably fitted into a shaft support 63 provided between the case body 37 and the case body 37. Further, thrust washers 65.65 are interposed between the side gear 55.57, the cover 39, and the case body 37, respectively.
Each side gear 55 meshes with the pinion gear 53.
It is receiving a thrust force of 57. A shaft 67 connected to the left rear axle 13 is spline-connected to the left side gear, and a shaft 69 connected to the right rear axle 15 is spline-connected to the right side gear 57.

An annular chamber is formed between the differential case 35 and the left side gear 55. Inside this annular chamber, a plurality of outer friction plates 71 are provided on the inner periphery of the differential case 35, and a plurality of outer friction plates 71 are provided on the outer periphery of the side gear 55. The outer friction plates 71 and inner friction plates 73 arranged alternately are spline-engaged in the rotational direction. These inner and outer friction plates 71.73
Both are movable in the axial direction. In this way,
A friction clutch 75 is configured.

The side wall of the cover 39 facing the left side surface of the friction clutch 75 serves as a receiving surface 77 for the pressing force that engages the friction clutch 75, as will be described later.

A ring-shaped cylinder member 79 is fixed to the right end side of the differential carrier 31. A ring-shaped piston member 81 is slidably engaged with the cylinder member 79 to form a pressure chamber 83.
O-rings 85 and 87 are interposed on the sliding surfaces between these members to maintain the pressure chamber 83 in a liquid-tight state. A hydraulic actuator 89 is configured by the cylinder member 79 and the piston member 81. This actuator 89 generates a pressing force to engage the friction clutch 75.

The piston member 81 is in contact with a pressing member 93 via a needle bearing 91. Four bushing rods 95, which are arranged at equal intervals on the circumference and slidably penetrate the case body 37, are integrally attached to the pressing member 93 by spring pins 97, respectively. This bushing rod 95 is divided into left and right halves, and a fuse member 99 serving as a fuse means is interposed between these halves. The bushing rod 95 can press the friction clutch via the pressure ring 101. More than 9 needle bearings
Each member from 1 to the pressure ring constitutes a pressing force transmission system. In addition, the case body 37 and the pressing member 93
As shown enlarged in FIG. 1(b), contact surfaces 103 and 105 are respectively provided, and together with the fuse member 99, they constitute a fuse means.

As shown in FIGS. 1(c) and 1(d), the fuse member 99 is a cylindrical member made of low carbon steel having small diameter portions 107, 107 at both ends, and the small diameter portions 107, 107 are connected to left and right bushing rods. 95 and 95, and is interposed between them. When the pressing force from the actuator 89 exceeds a predetermined value, this fuse member 99 is plastically deformed in the pressing direction as shown by the broken line in FIG. Shorten the total length of the transmission system. Before the nine fuse members are deformed, there is a gap between the contact surfaces 103 and 105 and they are not in contact with each other, but after the deformation, the pressing member 93 moves to the left only for the deformed valve, and the contact surfaces 103 and 105 are moved to the left. bump into each other. In this way, when the fuse member 99 is deformed, the contact surfaces 103 and 105 come into contact with each other, and the friction clutch 75
No further pressing force is applied to it.

Hydraulic pressure is supplied to the pressure chamber 83 of the actuator 8.9 from a pressure source 111 via a control valve system fi113. The control valve device 113 can be operated manually from the driver's seat or automatically by a signal from a sensor that detects slippage of the left and right rear wheels 17, 19, for example. In this way, actuator 89 is externally operated.

Next, the functions of this embodiment will be explained.

When hydraulic pressure is supplied to the pressure chamber 83 of the actuator 89,
The piston member 81 presses and engages the friction clutch 75 with the receiving surface 77 via a transmission system. II rubbing cut 7
5 is fastened, the differential case 35 and the side gear 55 are connected, and the differential rotation between these members is limited according to the fastening force of the friction clutch 75. Therefore, the left and right side gears 5
Differential rotation between 5.57 and 57 is limited. This limit amount can be adjusted by increasing or decreasing the hydraulic pressure supplied to the pressure chamber 83.
This is done by adjusting the pressing force of step 9.

When the hydraulic pressure supply to the pressure chamber 83 is stopped, the pressing force disappears, the friction clutch 75 is released, and the differential device 5
9 performs normal differential distribution.

When engaging the friction clutch 75, for example, the control device 11
Even if a failure occurs in the regulator No. 3 and an abnormally high pressure is applied to the actuator 89, the fuse member 99 deforms and the stopper means works as described above, so a pressing force exceeding a predetermined value is not applied to the friction clutch 75. No. Therefore, deformation of the friction plate of the friction clutch 75, the pressure ring 101, the differential case 35, the differential carrier 31, etc. does not occur.

Therefore, the pinion gear 53 of the differential device 59
and the meshing condition between the left and right side gears 55, 57 or the drive pinion gear 33 and the ring gear 47 does not deteriorate,
No noise or damage to these gears will occur.

Next, functions corresponding to the performance of the vehicle shown in FIG. 2 will be explained.

Whether to release the friction clutch 75 when cornering or
Alternatively, if the fastening force is loosened appropriately, differential rotation between the left and right rear wheels 17, 19 is allowed, allowing smooth cornering.

For example, if the friction clutch 75 is engaged when the left rear wheel 17 slips, driving force is also sent to the right rear wheel 19. At this time, even if a large pressing force is generated on the actuator 89, as described above, the load of the pressing force exceeding a predetermined value is regulated, so the engagement force of the friction clutch 75 will not become excessive.

Therefore, an excessive load will not be concentrated on the shaft systems such as the axle 15 and the shaft 69 on the right rear wheel 19 side that is being driven, and there is no risk of damage to the shaft systems.

Next, a second embodiment will be explained with reference to FIG. Similar to the first embodiment, this embodiment is an example used in the rear differential of the vehicle shown in FIG. Hereinafter, the differences from the first embodiment will be briefly explained while referring to the same members as those in the first embodiment with reference to the numbers in FIG. 1.

In addition, in the following description, the left and right directions are assumed to be the left and right directions in FIG. 3.

The cylinder member 115 is provided on the right end side of the differential carrier 31. A piston member is slidably engaged with the cylinder member 115 to form a pressure chamber 117 and constitute an actuator 119 . Actuator 119 generates a pressing force to engage friction clutch 75. As shown in FIG. 3, this piston member is divided into left and right halves, and a fuse member 125 constituting a fuse means is interposed between these left and right piston members 121 and 123.
I'm here. Piston member 121, 123 and cylinder member 1
15 and 0 ring 127.129.131.13
3 are interposed, respectively, to maintain the pressure chamber 117 in a liquid-tight state. The 0-rings 127° and 129 may be omitted.

The left piston member 121 is in contact with the pressing member 135 via the needle bearing 91. Four bushing rods 137 are integrally attached to the pressing member 135 by spring pins 97. The bushing rod 137 slidably passes through the case body 37 and the pressure ring 1
01 so that the friction clutch 75 can be pressed.

In this way, the portion from the left piston member 121 to the pressure ring 101 serves as a transmission system for the pressing force of the actuator 119.

Similar to the first embodiment, the fuse member 125 is a cylindrical member made of low carbon steel having small diameter portions 139 at both ends, and the both ends are inserted into grooves 141 provided in each of the left and right piston members 121 and 123. are engaged and installed. Further, a fuse member 1 is disposed between the piston members 121 and 123.
A stopper ring 14 that together with 25 constitutes a fuse means.
3 is arranged and engaged with a groove 145 provided in the cylinder member 115. The fuse member 125 is the actuator 11
When the pressing force from 9 exceeds a certain value, plastic deformation occurs in the pressing direction and the total length of the transmission system becomes shorter. The stopper ring 143 is caused by the deformation of the fuse member 125 and the right piston member 123.
When the fuse member 125 moves to the left, it comes into contact with this, but before the fuse member 125 is deformed, it is provided at a position where it does not come into contact with the piston member 123. Therefore, the pressing force lower than the predetermined value is transmitted through the transmission system to Il! However, a large pressing force exceeding a predetermined value is transmitted to the friction clutch 75, and the stopper ring 143 stops and no load is applied to the friction clutch 75.

Other configurations, functions, effects, etc. are the same as in the first embodiment.

In addition, in the present invention, the fuse member may be configured so that when a force of a certain value or more is applied, the fuse member does not undergo plastic deformation as in each of the above embodiments, but undergoes elastic deformation. With this configuration, for example, in each embodiment, when a pressing force of a certain value or more is applied, each stopper works due to the elastic deformation of the fuse member, and when the pressing force returns to the normal value, the fuse member returns to its original size. Since the differential device 259 returns to its original shape, the differential limiting function of the differential device 259 is not impaired and can always be maintained normally regardless of whether an excessive pressing force is generated.

In addition, the power transmission device of the present invention can be applied to other so-called two-wheel clutches and the like.

[Effects of the Invention] As described above, the power transmission device of the present invention can arbitrarily adjust the magnitude of the transmitted torque by adjusting the engagement force of the friction clutch. Further, even if a pressing force exceeding a predetermined value is generated on the actuator, the force is not applied to the *S clutch, etc., and therefore deformation or damage to the power transmission system can be prevented.

[Brief explanation of the drawing]

Figure 1 relates to the first embodiment, (a) is a sectional view showing this embodiment together with other members, (b) is an enlarged view of part A in (a), and (c) is (a). ) Enlarged view of part B in figure, (
d) The figure is a view taken along arrow a-a in figure (C), Figure 2 is a schematic diagram showing power transmission of a vehicle using the embodiment of Figure 1, and Figure 3 is a cross-section of the main part of the second embodiment. FIG. 4 is a sectional view of a conventional example. 35... Differential case (first rotating member) 55... Side gear (second rotating member) 59... Differential device 75... Friction clutch 77... Reception surface 89. 119... Actuator

Claims (1)

[Claims] A friction clutch includes first and second rotating members arranged coaxially so as to be relatively rotatable, and a plurality of friction plates arranged alternately with each other and individually engaged with the first and second rotating members. , an actuator that can be pressed to engage the friction clutch, and a fuse means that operates when the pressing force of the actuator exceeds a predetermined value to restrict an increase in the pressing force. A power transmission device characterized by: