JPS6138226A - Automatic regulating clutch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a self-adjusting clutch comprising two parallel multi-plate clutches, one of which is a viscous type clutch. The other multi-disc clutch is a friction clutch, which has one inner and one outer clutch part, and is arranged in a ring chamber formed by these two clutch parts, and has two inner clutch parts and an outer clutch part (two clutch parts alternately). It consists of two sets of discs, each consisting of a number of discs that are connected so that they cannot rotate relative to each other, one set of discs forming a viscous type clutch and the other set of discs forming a friction clutch. The invention relates to a type of viscous clutch in which the inner and outer discs of the viscous clutch are kept at an axial distance greater than the thickness of the discs disposed between them.

[Conventional technology]

A type of so-called viscous type clutch is known in which friction clutches are arranged in parallel.In this case, the friction clutch compensates for the decrease in torque that occurs when the viscous type clutch is heated, and accepts part of the torque transmission. Its role is to return the viscous clutch to a low temperature range by holding it (U.S. Patent No. 4,05
8, No. 027). The operation of the friction clutch is caused by the action of the temperature increase of the viscous clutch and the resulting pressure increase acting on one differential piston.

A disadvantage of self-adjusting clutches of this type is that the viscous clutch, which is primarily responsible for torque transmission, has a significantly temperature-dependent torque characteristic. That is, the operation of the friction clutch will also be affected at the same time, resulting in an uncontrollable transmission ratio in the self-adjusting clutch.

Another difficulty lies in the following points. That is, the working chambers of the viscous clutch and the friction clutch are not separated from each other, so that both clutches must be loaded with the same fluid. As a result, it is not possible to provide the friction clutch with an optimum friction ratio.

Another difficulty is that the maximum torque cannot be clearly defined. This is because the maximum torque is dependent on the respective temperature of the viscous clutch.

[Problem to be solved by the invention]

SUMMARY OF THE INVENTION It is an object of the invention to provide an automatically actuating adjustable clutch which transmits a clearly defined maximum rated moment and which operates essentially independently of the transmission characteristics of the viscous clutch. In this case, the viscous clutch and the friction clutch can each be loaded with an optimal medium.

[Means to solve the problem]

The present invention has solved these problems as follows. That is, (a) the viscous clutch and the friction clutch are sealed and separated from each other by one ring piston that is movable in the axial direction; (/1) between the ring piston and one pressure plate arranged upstream on the ring piston side of the friction clutch;
This is because the viscous clutch has an extremely small transmittable rated torque compared to a friction clutch.

〔Effect of the invention〕

The friction clutch of the present invention provides the following advantages. That is, the temperature-related uncontrollable torque characteristics of the viscous clutch do not lead to an uncontrollable transmission ratio, and the maximum transmittable torque of the self-adjusting clutch is limited by the friction clutch side stopper hitting the ring piston. This means that

Even if a special pressure buildup were to occur in the viscous clutch, the ring piston would not hit the stop and cause an undesirably large torque to be miscarried.

According to one embodiment, a self-adjusting clutch is arranged in the drive path connecting the two axles with each other, in which case a torque transmittable by the self-adjusting clutch is introduced from the engine into the drive path. The maximum torque exceeds the maximum torque by a very small amount.

In this embodiment, the self-adjusting clutch automatically engages the second drive axle in the event of slip in the main drive axle, and at the same time in response to a load in the drive path, i.e. during tight cornering. It makes it possible to avoid loads that are larger than the driving moment.

Such use of the self-adjusting clutch of the present invention provides an automatically engaging four-wheel drive system, which has the added advantage of not requiring front and rear differentials between the axles. enable.

According to another embodiment of the invention, a self-adjusting clutch is used as a differential brake.

In this embodiment, the self-adjusting clutch acts as a differential brake that is activated when necessary, and even in this case it is possible to avoid the traction forces between the drive axles or between the drive wheels that occur when driving in tight corners. .

Incidentally, a type of hydraulic or fluid clutch in which the transmittable torque is adjusted by changing the amount of working fluid is already known (UK Patent No. 414,662). In this case, the volume is transferred from one or more working chambers to a reservoir chamber and thereby adjusted until the clutch is completely released. The disadvantage of this known example is that the torque change occurs very slowly in response to the fluid movement and is therefore unsuitable for all applications in which a short or abrupt change to the release position is required for safety reasons. .

It is also known to operate differential locking devices via electromagnets (German Patent Application No. 292,010)
7 specification). However, this example also suffers from the disadvantage that the magnetic field must be maintained during the effective period, which results in large current consumption. Furthermore, by means of a friction clutch that produces a locking effect, it is not possible to produce an automatic connection to a differential locking device or an additional drive axle.

Based on this recognition, the present invention aims to rapidly switch the self-adjusting clutch to its release position, and is also characterized by the following points: On the opposite side, a ring flange is provided, the ring flange being supported by one or more springs, the spring force of which exerts a force on the ring piston. The force of the ring flange is larger than the force of the spring, and the (t)ring flange is movable by the magnetic field of one electromagnet toward one stopper against the force of the spring located on the opposite side to the friction clutch side. (g) The amount of movement of the ring flange caused by the magnetic field is set so that when the ring piston contacts the stopper, the action of the push spring is completely nullified.

According to this configuration, the friction clutch that determines the driving torque is moved to the release position of the self-adjusting clutch by the operation of the electromagnet and by the movement of the ring flange forming the bottom plate of the friction clutch in a direction away from the friction clutch. This results in a sudden change in

Such a self-adjusting clutch arrangement is particularly advantageous when used for automatically switching connections from one drive axle to another of a motor vehicle drive. in this case,
The response of the clutch by actuation of the electromagnet can be triggered, for example, via the brake pedal. In such a case, when braking, the multi-axis drive is eliminated, thereby avoiding the difficulties that can occur especially in the case of motor vehicles equipped with anti-lock devices.

In the case of anti-lock devices, the wheel of the drive wheel released via the electromagnet becomes the driven free-rotating wheel upon braking.

The principle of the self-adjusting clutch of the present invention can of course also be applied to differential locking devices in which the differential locking action is released by operating the brake pedal, for example, so as not to adversely affect the anti-locking device. can.

〔Example〕

FIG. 1 shows a self-adjusting clutch according to the invention in partial longitudinal section. The self-adjusting clutch essentially consists of an outer clutch part 1 and a two-part inner clutch part 2. The inner clutch part 2 has one through hole 16 in which a spline 1 is inserted.
5 is formed. This inner clutch part 2 is axially fixed on a splined shaft from the transmission. The outer clutch part 1 is provided with a connecting flange 14 to which a drive shaft (not shown) of a drive path can be fastened via a fixing hole 13.

A viscous type clutch 5 is located in the left half of the figure, and this viscous type clutch 5 consists of a number of discs 6 which are connected to each other in a relatively unrotatable manner, alternately connecting an outer clutch part 1 to an inner clutch part 2. It consists of These disks 6 belong to the foreign clutch part 1 and the inner clutch part 2, respectively.
A spacer 7 made of, for example, a wire ring is inserted between them.

The disc 6 has inner and outer axial position stops 18a.

The axial movement is restricted by 18h.

In the right half of the figure, friction clara=y-ii is shown.

This friction clutch 11 also consists of a number of disks 12 which are connected alternately to an outer clutch part 1 and an inner clutch part 2 in a rotationally fixed manner.

The rotationally fixed connection of both the disc 6 of the viscous clutch 5 and the disc 12 of the friction clutch 11 with the two clutch parts 1.2 is effectively effected by a splice.

A pressure plate 10 is arranged inside the friction clutch 11 and is also connected to the outer clutch part 1 in a rotationally fixed manner. One ring piston 3 is arranged between the viscous clutch 5 and the friction clutch 11, and the ring piston 3 connects the working chambers of both the viscous clutch 5 and the friction clutch 11 to each other via a seal ring 4. Separated. In this way, the working chamber of the viscous clutch 5 and the rot [friction clutch 11
It is possible to fill the working chamber with another liquid,
Furthermore, the friction clutch 11 may be a dry type instead of a wet type without any problem.

Between the ring piston 3 and the pressure plate 10, a pressure spring 8 is arranged, which is arranged in a number of holes distributed evenly in the circumferential direction of the ring piston 3.

Assigned to the pressure spring 8, projections 9 are provided on the ring piston 3, which together with the holes for the pressure spring 8 fit into the projections 19 of the pressure plate 10. In this way, the ring piston ring 3 is also connected to the external clutch part 1 in a relatively rotationally fixed manner via the pressure plate 10, so that an undesirable rotation of the ring piston 3 is prevented.

If a relative movement occurs between the two clutch parts 1.2 due to slippage in the drive axle, the discs 6 of the viscous clutch 5 will move relative to each other.

In this case, the spacer 7 ensures that the discs 6 do not come into contact with each other.

Thus, the viscous clutch 5 also functions as a clutch that does not generate contact friction. The shearing force acting on the viscous liquid filling the viscous clutch 5 causes heating of the viscous liquid, and this heating is accompanied by pressure acting on the ring piston 3 due to an increase in volume. This pushes the ring piston 3 toward the friction clutch 11,
At the same time, the push spring 8 is forced into tension. This push spring 8
Via the overpressure generated in the viscous clutch 5 is transmitted directly as a vertical force to the friction clutch 11, which performs a torque transmission between the two clutch parts 1, 2.

The stop 17 makes it possible to adjust the maximum normal force on the friction clutch 11 in conjunction with the pressure spring 8 .

The pressure spring 8, which is shown as a helical spring in FIG. In order to lead to this, there is a possibility that the disc spring will work within the descending characteristic of the spring characteristic curve. Of course, it is also possible to select a spring correspondingly with an approximately flat characteristic range near the top of the spring characteristic curve, which makes it possible to maintain a constant spring force within the wear range.

The length of the push spring 8 is set so that no normal force is applied to the friction clutch when the self-adjusting clutch is not under load.

FIG. 2 shows a basic example of the arrangement of a self-adjusting clutch as an additional device in the front-rear drive path of a motor vehicle. A front axle 22 is driven via an engine 20 and a transmission 21 . As slip occurs in the wheels of the front axle 22, the self-adjusting clutch in the additional device 24 begins to transmit torque to the wheels of the rear axle 23 in the manner described above. This is because in this case a relative rotational speed occurs between the wheels of the front axle 22 and the wheels of the rear axle 23 due to slippage, which relative rotational speed triggers the self-adjusting clutch.

FIG. 3 shows a conventional differential gear device 26, by which both left and right wheels of one axle are driven via respective drive shafts 27.

A self-adjusting clutch is installed between the ring gear 25 and one of the driven gears in order to provide a braking effect for the differential gear 26 in the event of slippage on one of the two wheels. This self-adjusting clutch ensures that its maximum transferable torque is transmitted to the other wheel even when one wheel slips.

Another self-adjusting clutch according to the invention is shown in partial longitudinal section in FIG. The self-regulating clutch primarily consists of an outer clutch part 101 and a two-part inner clutch part 102. Inner clutch part 1
02 has one through hole 116, and this through hole 1
A spline 115 is formed within 16. This inner clutch part 102 is axially fixed on a splined shaft from the transmission. Outer clutch part 101
is provided with a connecting flange 114, to which a drive 1111 (not shown) of a drive path can be fastened via a fixing hole 113.

A viscous type clutch 105 is located in the left half of the figure, and this viscous type clutch 105 consists of a number of disks 106 that are connected to the outer clutch portion 101 and the inner clutch portion 102 alternately and in a relatively unrotatable manner. It consists of Between these disks 106, which belong to the outer clutch part 101 and the inner clutch part 102, respectively, a spacer 107 is inserted, which consists of a wire ring, for example.

Disc 106 has inner and outer axial detents 118 &
, 118h restricts the axial movement.

A friction clutch 111 is shown in the right half of the figure. This friction clutch 111 is also the outer clutch portion 101.
It consists of a number of discs 112 which are alternately and relatively rotationally connected to the inner clutch part 102 and the inner clutch part 102.

The disc 106 of the viscous clutch 105 and the disc 112 of the friction clutch 111 are both clutch parts 101.
, 102 is effectively achieved by splines.

A pressure plate 110 is arranged on the inside of the friction clutch 111, which pressure plate 110 is also connected to the outer clutch part 1.
01 in a relatively unrotatable manner. One ring piston 103 is arranged between the viscous clutch 105 and the friction clutch 111, and this ring piston 103 connects the working chambers of both the viscous clutch 105 and the friction clutch 111 to the seal ring 104. are separated from each other through. In this way, it is possible to fill the working chamber of the viscous type latch 105 and the working chamber of the friction clutch 111 with different liquids, and the friction clutch 111 can be a dry type instead of a wet type. I can do that without any problem.

Between the ring piston 103 and the pressure plate 110, a pressure spring 108, which is arranged in a number of holes uniformly distributed in the circumferential direction of the ring piston 103, acts. A projection 119 is attached to the push spring 108 and is attached to the ring piston 103.
are provided, and these protrusions 119 push springs 10
It fits into the protrusion 109 of the pressure plate 110 along with the hole for 8. In this way, the ring piston ring 103 is also connected in a relatively rotationally fixed manner to the outer clutch part 101 via the pressure plate 110, so that an undesirable rotation of the ring piston 103 is prevented.

If a relative movement occurs between the two clutch parts 101, 102 due to slippage in the drive axle, the discs 106 of the viscous clutch 105 will move relative to each other. In this case, the spacer 117 is the disk 106
ensure that there is no contact friction with each other. Thus, the viscous clutch 105 also functions as a clutch that does not generate contact friction. The shearing force acting on the viscous liquid filled in the viscous clutch 105 causes heating of the viscous liquid, and this heating is accompanied by pressure acting on the ring piston 103 due to an increase in volume.

As a result, the ring piston 103 is connected to the friction clutch 11.
1, and at the same time the push spring 108 is forced to tense. The overpressure generated in the viscous clutch 105 is transferred to the friction clutch 11 via this pressure spring 108.
1 as a vertical force, and the friction clutch 111 carries out the torque transmission between the two clutch parts 101, 102.

Stop 117 allows adjustment of the maximum normal force on friction clutch 111 in conjunction with push spring 108 .

The pressure spring 108, which is shown as a helical spring in the figure, may of course also be a suitable disk spring, in which case the spring characteristics are such that the wear of the friction discs of the friction clutch leads to a corresponding increase in the normal force. Within the range of the descending characteristic of the curve, the possibility arises that the disc spring will work. Of course, it is also possible to correspondingly select a spring with an almost flat custom range near the top of the spring characteristic curve, which makes it possible to maintain a constant spring force within the wear range.

The length of the push spring 108 is such that no normal force is applied to the friction clutch when the self-adjusting clutch is not loaded.

The above structural form and operational form are the same as the example shown in FIG.

A ring flange 128 is disposed on the opposite side of the friction clutch 111 from the ring piston 103, and this ring flange 128 itself
It is supported by two springs 129. This spring 129 is designed so that the force it exerts on the ring flange 128 is greater than the sum of the spring forces of the push springs 108. The ring flange 128 thus serves as a stationary housing limiting wall for the friction clutch.

The spring 129 rests on an axial stop ring as a stop 131 via an insert disk.

The ring flange 128 has a flange-like extension, which cooperates with an electromagnet 130 configured in the form of a ring. The housing of this electromagnet 130 is fixedly connected to a transmission housing 133, for example by screwing.

Upon activation of the electromagnet 130 by the voltage source, this electromagnet 130 exerts a pulling force on the extension of the ring flange 128 and tends to pull the ring flange 1.28 away from the friction clutch 111 against the force of the spring 129. spring 12
In this case, in order to minimize the holding force against the electromagnet 130, it is preferable to design the magnet 9 so that it works in a range of 2 when the slope is downward.

The amount of movement of the ring flange 128 obtained in this manner is so large that no vertical force can be applied to the friction clutch 111 from the push spring 108 any longer.

A clutch that is completely released by the movement of the ring flange 128 no longer transmits torque, which means that if the vehicle is equipped with an anti-lock device, it will automatically connect to another drive axle. is advantageous to
It also turned out to be necessary. In this case, activation of the electromagnet 130 can be effected simply via a brake light switch.

In order to reliably prevent friction of the ring-shaped extension of the ring flange 128 on the electromagnet 130 during rotation of the clutch, it is necessary to limit the amount of movement of the ring flange 128 itself by means of a stopper. This means that spring 129
1173 to lock the lever 130 in the operating position (if designed, this can be done by a stopper 131).

[Brief explanation of the drawing]

Fig. 1 is a partial longitudinal sectional view of the self-adjusting clutch of the present invention, Fig. 2 is a layout diagram in the front and rear drive path of an automobile, Fig. 3 is a longitudinal sectional view of an example of use as a differential brake, and Fig. 4 is a partial longitudinal sectional view of the self-adjusting clutch of the present invention. FIG. 7 is a partial longitudinal IT view of another self-adjusting clutch of the invention. 1.101...Outer clutch part, 2,102...
Inner clutch part, 3,103...ring piston,
4.104...Seal ring, 5.105...Hiscus type clutch, 6 + l Q l'+... Disc,
7.107...Spacer, 8.108...Press spring, 9.109...Protrusion, 10,110...Pressure plate,
11.111...Friction clutch, 12.112...
Disc, 13.113...Fixing hole, 14,114...
Connection flange, 15°115...Spline, 16,
116...Through hole, 17, 117-...Stopper,
18a, 118a+18h+118b...Axial position stop, 19,119...Protrusion, 20...Engine, 2
DESCRIPTION OF SYMBOLS 1... Transmission, 22... Front axle, 23... Rear axle, 24... Additional device, 25... Belleville spring, 26...
Differential gear device, 27... Drive shaft, 128... Ring flange, 129... Spring, 130... Electromagnet, 1
31... Stopper, 132... Taking pin, 133...
··transmission.

Claims (1)

[Claims] 1) A self-adjusting clutch comprising two multi-plate clutches arranged in parallel, one multi-disc clutch forming a viscous clutch and the other multi-disc clutch forming a friction clutch. , an inner and an outer clutch part, and a plurality of clutch parts arranged in a ring chamber formed by both clutch parts and connected alternately to the inner clutch part and the outer clutch part in a relatively rotationally fixed manner, respectively. It consists of two disc sets consisting of discs, one disc set forms a viscous type clutch, and the other disc set forms a friction clutch, and the inner side of the viscous type clutch In a type in which a disc and an outer disc are maintained at an axial distance greater than the thickness of the discs disposed between them, (a) a viscous clutch (5) and a friction clutch (11) are used.
) and one ring piston (
(b) The sliding stroke of the ring piston (3) is controlled by one stopper (17) located on the side facing the friction clutch (11). (c) Ring piston (3) and friction clutch (11)
one pressure plate (10) placed upstream on the ring piston side of the
At least one push spring (8) is arranged between the friction clutch (1) and (d) the viscous clutch (5).
2) A drive path in which the self-adjusting clutch connects the two axles (22, 23) for transmission. Claim 1, wherein the torque transmittable by the self-adjusting clutch is very slightly above the maximum torque introduced from the engine into the drive path. 3) A self-adjusting clutch according to claim 1, wherein the self-adjusting clutch is used as a differential brake. 4) A self-adjusting clutch comprising two parallel multi-disc clutches. , one multi-plate clutch is a viscous type clutch, and the other multi-plate clutch is a friction clutch, with one inner and outer clutch part and a ring chamber formed by both clutch parts. It consists of two disc sets consisting of a large number of discs arranged in the inner clutch part and the outer clutch part and connected to the inner clutch part and the outer clutch part in a relatively unrotatable manner, and one of the disc sets is a viscous type. The other disk set forms a friction clutch, and the inner disk and outer disk of the viscous clutch have an axial spacing that is larger than the thickness of the disks arranged between them. (a) The viscous clutch (105) is replaced by a friction clutch (105).
111) are sealed and separated from each other by a first ring piston (103) that is movable in the axial direction, and (b) the sliding stroke of the ring piston (103) is caused by friction. It is limited by one stopper (117) arranged on the side facing the clutch (111), and (c) the ring piston (103) and the friction clutch (1
11) One pressure plate (
at least one push spring (108) between the
) are arranged, (d) the viscous clutch (105) has an extremely small transmittable rated moment compared to the friction clutch (111), (e) the friction clutch (111), Ring piston (1
03), one ring flange (128
), the ring flange (128) is supported by one or more springs (129), and the spring force of the spring (129) is assigned to the ring piston (103). The force of the push spring (108) is larger than that of the push spring (108), and the ring flange (128) is
The magnetic field of the stopper (129) causes one stopper (129) to move against the force of the spring (129) located on the opposite side to the friction clutch side.
(h) ring flange (1) produced by a magnetic field;
28) The amount of movement of the automatic adjusting clutch is set such that the action of the push spring (108) is completely nullified when the ring piston (103) contacts the stopper (117).