JPH09257058A - Multidisk frictional engaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the occurrence of a shift shock by a method wherein a clearance between plates is brought into a proper value and a plate attitude are brought into a proper state. SOLUTION: Drive plates 3a, 3b,... are formed in a wave-form having a plurality of kinds of waviness in a peripheral direction. This constitution provides spring properties and facing materials 4 are stretched between the two surfaces of the drive plates 3a, 3b,.... By setting the set loads of the drive plates 3a, 3b,... such that the set load is gradually decreased, in order, from that of the drive plate situated near a piston 173 during engagement of a clutch, transmission torque of a clutch gradually rises, whereby a shift shock is prevented from occurring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction engagement device used in, for example, an automatic transmission, and more particularly to a multi-disc friction utilizing friction engagement forces of a plurality of drive plates and driven plates which are alternately arranged. The present invention relates to an engagement device.

[0002]

2. Description of the Related Art In an automatic transmission according to the prior art, various drive plates and driven plates, such as a hydraulic multi-plate clutch, a forward clutch, a reverse clutch, a high clutch, and a low andry bus brake, are alternately arranged. Gear shifting is performed by utilizing the multi-disc friction engagement device.

A conventional multi-plate friction engagement device will be described with reference to FIGS.

FIG. 10 shows a vertical transaxle type drive system disclosed in Japanese Unexamined Patent Publication No. 3-135841.
In this drive system, a transmission case 104 is joined to the rear of the torque converter case 100 and the differential case 102. A transfer case 106 is joined to the rear of the transmission case 104, and an oil pan 108 is attached to the lower part of the transmission case 104.

A torque converter 110 provided in the torque converter case 100 has a lockup clutch 112 and is connected to a crankshaft (not shown) of the engine. Then, the rotational force from the torque converter 110 is transmitted to the automatic transmission 116 in the transmission case 104 via the input shaft 114. The output shaft 118 from the automatic transmission 116 outputs a rotational force coaxially with the input shaft 114, and the output shaft 118 is coaxially connected to the center differential device 120 in the transfer case 106.

Further, inside the transmission case 104, the front drive shaft 122 is arranged in parallel with the input shaft 114 and the output shaft 118. The rear end of the front drive shaft 122 is connected to the center differential device 120 via a pair of reduction gears 124 and 126.
The front end of 2 is connected to the front wheels via a front differential device 128 in the differential case 102. On the other hand, the center differential device 12
From 0, a rotational force is output to the rear drive shaft 130, and this rear drive shaft 130 is connected to the rear wheels via a propeller shaft, a rear differential device, and the like.

The automatic transmission 116 has a front planetary gear 132 and a rear planetary gear 134. A high clutch 136, a reverse clutch 138, a brake band 140, a forward clutch 142, an overrunning clutch 144, a low and reverse brake 146, and one-way clutches 148 and 150 are provided for the front planetary gear 132 and the rear planetary gear 134. . Then, by selectively engaging each of these friction engagement devices, the forward movement 4
It is designed so that one shift speed can be obtained in reverse.

In front of the automatic transmission 116, an oil pump 152 is provided so as to connect the impeller sleeve 110a of the torque converter 110 and the drive shaft 154 so as to always drive the impeller sleeve 110a. On the other hand, the electronic hydraulic control device 156 is composed of a control valve body or the like housed in the oil pan 108. By supplying or discharging hydraulic pressure to or from the friction engagement devices via the control valve body, the electronic hydraulic control device 156 is selected. To achieve proper engagement.

Center differential device 120
Is a first sun gear 160 connected to the output shaft 118,
The second sun gear 162 connected to the rear drive shaft 130
And a first pinion 164 that meshes with the first sun gear 160.
And a second pinion 166 that meshes with the second sun gear 162.
And a carrier 168. A hydraulic multi-disc clutch (LSD) 170 for limiting the differential is arranged in parallel with the center differential device 120 between the carrier 168 and the second sun gear 162. Torque distribution control and differential limit control are performed by the hydraulic multi-plate clutch 170.

For example, a multi-plate friction engagement device such as a hydraulic multi-plate clutch 170, a forward clutch 142, a reverse clutch 138, a high clutch 136, and a low-and-leaves brake 146 is a friction rotary plate shown in FIG. 11, that is, a driven plate. 181, 182, ..., Drive plates 191, 192 ,.

A plurality of protrusions for spline coupling with grooves (not shown) formed in a member connected to an input shaft such as a clutch drum are provided on the outer peripheral sides of the driven plates 181, 182, .... ing. Further, on the inner peripheral side of the drive plates 191, 192, ..., A plurality of protrusions for spline coupling to grooves (not shown) formed in a member connected to the output shaft such as a clutch hub are provided. ing. In addition, the drive plates 191, 19
Facing members (lining) on both sides of 2, ...
200 are provided.

Next, referring to FIG. 12, the structure of the high clutch 136 will be described as an example of the multi-plate friction engagement device.

A plurality of spline grooves 171a extending in the axial direction are formed on the inner peripheral side of the clutch drum 171 connected to the input shaft 136, and these spline grooves 171 are formed.
A plurality of driven plates 181, 182, ...
Is spline-fitted to the clutch drum 171.
On the other hand, also on the outer peripheral side of the clutch hub 172 connected to the front planetary gear 132, a plurality of spline grooves 17 are formed.
2a are engraved in the axial direction, and these spline grooves 1
72a through a plurality of drive plates 191, 19
2, ... Are spline-fitted to the clutch hub 172. Here, the driven plates 181, 182, ... And the drive plates 191, 192, ... Are alternately arranged coaxially one by one, and are respectively movable in the axial direction.

A piston 173 is provided on one end side of the clutch drum 171 so as to be movable in the axial direction. Further, between the piston 173 and the spring retainer 174 fixed to the clutch drum 171, a plurality of springs 175 are arranged in the circumferential direction with a space therebetween. It is biased in the opening direction. When the hydraulic oil is supplied into the hydraulic chamber 176 formed between the back surface of the piston 173 and the clutch drum 171, the piston 1
73 moves forward against the spring force, and the pressure plate 17
The driven plates 181, 182, ... And the drive plates 191, 192 ,.

Reference numeral 178 is a retaining plate provided on the side of the driven plate 185 at the final stage, which receives the thrust load, and 179 is a snap ring.

The multi-plate clutch device has the above-mentioned structure, and includes a clutch drum 171 and a clutch hub 172.
In the case of transmitting the driving force between and, the hydraulic oil is supplied to the hydraulic chamber 176. As a result, the piston 173 advances toward the other end side and presses the driven plate 181 in the axial direction via the pressure plate 177. And
Transmission of driving force by pressing the driven plate 181, the drive plate 191, the driven plate 182, the drive plate 192, the driven plate 183, the drive plate 193, the driven plate 184, the drive plate 194, the driven plate 185, and the drive plate 195 in this order. Is done.

In the multi-disc clutch device as described above, a shift shock is likely to occur when the clutch is engaged, and therefore when used in an automatic transmission of an automobile, for example, the riding comfort may be reduced.

As a factor, first, the clearance between the driven plates 181, 182, ... And the drive plates 191, 192, .. They are different depending on the place of installation, and are non-uniform. Also,
The pressing force of the piston acts exclusively from one side of the plate. Further, since the plate is not always arranged in the vertical direction with respect to the axial direction and there is some inclination or inclination, a drag called a drag may be partially generated when the clutch is engaged.

Therefore, due to the non-uniform clearance between the plates and the variation of the plate posture when the clutch is engaged, the friction coefficient characteristic of the facing material 200 is also non-uniform, and a fastening shock, that is, a shift shock occurs when the clutch is engaged. As a result, the usability and operability may be deteriorated.

In order to reduce such shift shock, there is a prior art disclosed in, for example, Japanese Patent Laid-Open No. 366031/1992. In this prior art, a plurality of springs are arranged in the circumferential direction between adjacent outer plates, and the total set load of each spring between the outer plates is gradually changed from a low load to the outer plates. It is set so that the shift shock is reduced.

Further, as another prior art, there is, for example, Japanese Patent Laid-Open No. 4-366032. In this prior art,
An annular disc spring is arranged between at least one of the drive plates or between the driven plates, and there are multiple types of set loads for these annular disc springs, and the load is stepwise increased from a low load, so that a shift shock at the time of clutch engagement is achieved. Is being reduced.

[0022]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the prior arts described in Japanese Patent Publication No. 031 and Japanese Patent Laid-Open No. 4-366032, the set load of the spring element provided between the plates is configured to be gradually increased from a low load, and therefore, when the clutch is engaged. It is possible to gradually increase the transmission torque and reduce the shift shock.

However, in any of the prior arts, since the spring elements independent of the plate, that is, the springs equidistantly arranged in the circumferential direction and the annular disc spring are interposed between the plates, each time the clutch is engaged and disengaged. Moreover, only a specific part of the plate that receives these springs and annular disc springs comes into contact with the ends of the springs or the like. Therefore, each time the clutch is repeatedly connected and released, there is a possibility that a specific region, which serves as a spring receiver such as a spring, of the entire surface of the plate is gradually worn away, and durability is deteriorated. Further, since the springs or annular disc springs separate from the plates are additionally provided between the plates, the number of clutch component parts increases and the workability of the assembling work also deteriorates. Further, there is a drawback in that the weight and the moment of inertia increase due to the spring and the annular disc spring.

Therefore, an object of the present invention is to provide a multi-plate friction engagement device which can reduce the fastening shock without increasing the number of components. Another object of the present invention is to provide a multi-plate friction engagement device capable of reducing unevenness in temperature and reducing unevenness in temperature between plates.

[0025]

To achieve the above object, a multi-plate frictional engagement device according to the present invention has drive plates and driven plates, which are provided so as to be movable in the axial direction, arranged alternately. In the multi-plate frictional engagement device according to the present invention, one of the drive plate and the driven plate is formed as a spring plate having a spring property, and by this configuration, a separate spring element is formed. It is possible to keep the clearance between the plates constant without using them, and prevent the plates from tilting or falling.

Further, by forming the plate having the spring property into a wave shape having a plurality of undulations in the circumferential direction, it is possible to manufacture a spring plate having a desired spring characteristic with a relatively simple structure. .

Further, by setting the set load of the plates having the respective spring characteristics to be smaller according to the arrangement order of the plates having the respective spring characteristics, when the clutch is engaged, the plates are arranged in the order of smaller set loads. Since the connection is made, the connection torque can be gradually increased to reduce the fastening shock, that is, the shift shock.

Further, by setting the set load of the plates having each spring property so that the set load becomes smaller as the temperature at the installation position of each spring plate becomes lower, the plates having smaller set loads are connected in order. Shift shock can be reduced, and the higher the plate temperature, the larger the set load and the smaller the contact area and contact time. Therefore, it is possible to suppress excessive temperature rise and improve the temperature nonuniformity between the plates. .

[0029]

Embodiments of the present invention will be described below in detail with reference to the drawings. In addition, in each of the following embodiments, the same components as those in the above-described conventional technique are designated by the same reference numerals, and the description thereof will be omitted.

First, FIG. 1 is an enlarged sectional view showing an essential part of a multi-plate clutch device according to a first embodiment of the present invention. This clutch device comprises a clutch drum 171,
It is configured as a friction-type multi-plate clutch including a clutch hub 172, a piston 173, and the like. Further, a plurality of driven plates 1a, 1b, ... Are spline-fitted on the inner peripheral side of the clutch drum 171, and the thrust load of each of these driven plates 1a, 1b ,. Has become.

On the other hand, a plurality of drive plates 3a, 3 spline-fitted to the outer peripheral side of the clutch hub 172.
Facing materials 4 are stretched on both surface sides of b, ..., And are inserted between the driven plates 1a, 1b ,.

Here, the drive plates 3a, 3b, ...
As shown in the perspective view of FIG. 2, is formed in a corrugated shape having a plurality of undulations in the circumferential direction, and a facing material 4 is stretched by an adhesive or the like on both surfaces thereof. Each of these drive plates 3a, 3b, ... Is given a spring property by this undulation and is formed as a plate having a single spring property that does not require a separate spring element.
At the initial stage of contact, the drive plates 3a, 3b, ... Have point contact or line contact with the driven plates 1a, 1b, which oppose each other at the convex portions P, P ,. Then, at the final stage of contact, as shown in FIG. 4, the corrugated shape is elastically deformed into a flat annular body and comes into surface contact with the opposing driven plates 1a, 1b, ....

Here, each drive plate 3a, 3b,
The set load of ... Is set according to the arrangement order of the drive plates 3a, 3b ,.
That is, the set load is set to become smaller as it moves to the side of the piston 173 serving as the drive mechanism. More specifically, the drive plates 3a and 3b close to the piston 173 side are set to a relatively small load, and the drive plates 3c and 3d located in the middle are set to a relatively medium load, and the retaining plate 2 The last drive plate 3e close to is set to the highest load.

When the piston 173 advances to connect the clutch and urges the pressure plate 177, the set load of the drive plates 3a and 3b is the smallest, so that the driven plate 1a drives the drive plate 3 to set.
a is pressed, and the drive plate 3a presses the next driven plate 1b. The driven plate 1b presses the drive plate 3b having a small set load, and the drive plate 3b presses the driven plate 1c.

Next, when the drive plate 3c having a medium set load is pressed by the driven plate 1c, the drive plate 3c presses the driven plate 1d. As a result, the driven plate 1d
Is a drive plate 3d having a medium set load
And the drive plate 3d presses the driven plate 1e.

Finally, the driven plate 1e at the final stage
Presses the drive plate 3e having the largest set load, and the drive plate 3e presses the retaining plate 2.

That is, the contact of the plates is started in the ascending order of the set load, and the relative rotational speed difference between the plates is gradually reduced, and the plates are fastened. Further, due to the shape change of each drive plate 3a, 3b, ... At the initial stage of contact, as shown in FIG. 3, the wavy convex portion P is driven by the driven plates 1a, 1b ,. Although in point contact or line contact with the driven plate 1a, the corrugated shape is elastically deformed into a flat annular body as shown in FIG.
1b, ... makes contact with the entire surface.

According to the present embodiment configured as described above, since each drive plate 3a, 3b, ... Is formed as a plate having a spring property, separate and independent spring elements as in the prior art are used. Without this, the clearance between the plates when the clutch is released can be kept substantially constant by the spring force of the plates themselves, and the plates can be prevented from tilting or falling. Therefore, as compared with the prior art using a separate spring element, the shift shock can be mitigated without increasing the number of parts, the number of assembly steps, the product weight, and the moment of inertia. Furthermore, since the clearance between the plates and the posture of the plates can be appropriately maintained, the friction coefficient characteristics of the facing material 4 can be made uniform and stable between the plates.
It is possible to stabilize the shift shock for a long time,
It is possible to prevent a change in shift shock due to a change over time.

The drive plates 3a, 3b, ...
2 is formed in a corrugated shape having a plurality of undulations in the circumferential direction, the plate having a spring property can be easily obtained by the plurality of undulations. In addition, since the drive plates 3a, 3b, ... themselves have spring properties without using separate spring elements, the conventional drive plates are replaced by the drive plates 3a, 3b ,.
It is possible to realize reduction of shift shock and the like simply by replacing it with.

Further, each drive plate 3a, 3b, ...
The setting load of is set to be smaller according to the arrangement order of the drive plates 3a, 3b, ...
Start the connection in order from the plate with the smallest set load,
The clutch transmission torque can be gradually raised, and shift shock can be reduced.

Since each drive plate 3a, 3b, ... Is formed as a corrugated spring-like plate having a plurality of undulations in the circumferential direction and a facing material 4 stretched on both sides, the driven plates 1a, 1b ,. And the drive plates 3a, 3b, ... At the initial stage of contact, the wavy convex portions P, P, of the drive plates 3a, 3b ,.
While making point or line contact via the facing material 4 in ..., Relative rotation is performed. Therefore, unlike the above-described respective prior arts in which the ends of the spring and the annular disc spring are directly in contact with the background of the plate, the contact points between the plates are circumferentially protected while being protected by the facing material 4 until the completion of fastening. Since it is moving, the driven plate 1a,
It is possible to prevent abnormal wear of the parts 1b, ..., And it is possible to improve durability and reliability.

In the above embodiment, as shown in FIG. 5, the drive plate 3 closer to the piston 173 is used.
Assuming that the set loads of the drive plates 3a and 3b are reduced, the set loads of the drive plates 3c and 3d at the intermediate positions are set to be medium, and the set load of the drive plate 3e farthest from the piston 173 is increased, that is, the drive plate The case where the set load is set for each group of 3a, 3b, ... Has been described, but the present invention is not limited to this, and for example, FIG.
As described above, the set load may be increased stepwise individually for each drive plate 3a, 3b, ....

Next, a second embodiment of the present invention will be described with reference to FIG.

That is, the driven plates 11a, 11b, ... Of the present clutch device are spline-fitted to the inner peripheral side of the clutch drum 171 in the same manner as the driven plates 1a, 1b, ... Described in the first embodiment. The retaining plate 12 is adapted to receive the thrust load.

On the other hand, each drive plate 13a, 13
Similarly to the drive plates 3a, 3b, ... Described in the first embodiment, b, ... Are formed in a corrugated shape having a plurality of undulations in the circumferential direction to impart springiness,
Facing materials 4 are stretched on both sides.

Then, as shown in FIG. 8, the set load of the drive plates 13c and 13d, which is conventionally arranged in a high temperature portion where the plate temperature easily rises, is set to the maximum, and the drive plates 13c and 13d are arranged in the middle temperature portion where the plate temperature becomes a medium temperature. Set the set load of the drive plates 13a and 13b to a medium value,
Conventionally, the set load of the drive plate 13e arranged in a low temperature portion where the plate temperature tends to be low is minimized. More specifically, the set loads of the drive plates 13a and 13b located in the medium temperature part near the piston 173 side are set to medium, and the set load of the drive plate 13e located in the low temperature part farthest from the piston 173 is set small. The set load of the drive plates 13c and 13d located in the high temperature part in the middle is set to be the largest.

Therefore, when the clutch is engaged, the drive plate 13e, which has the lowest set load and has a low temperature in the past, comes into contact with the driven plate 11e prior to the other plates, and the entire surface sliding contact is started. That is, since the drive plate 13e has a small set load, the drive plate 13e elastically deforms from the corrugated shape to a flat annular body by contact with the driven plate 11e, and relatively rotates while contacting the driven plate 11e over the entire surface. The sliding contact over the entire surface is continued until the clutch engagement is completed.

Next, the drive plates 13a and 13b having a medium set load come into contact with the opposed driven plates 11a and 11b, and finally, the drive plate 13c having a high set load is reached only near the end of the clutch engagement. , 13d contact driven plates 11c, 11d. Here, in the first middle period of clutch engagement, the pressing force to the plate gradually increases, but the drive plate 13e set to a low load is in sliding contact with the driven plate 11e over the entire surface, whereas the drive plate 13e has the highest force. Drive plates 13c and 13 set to the load
d is a point contact or line contact at the wavy convex portions P, P, ....

That is, the smaller the set load is,
Due to the longer contact area and contact time, the amount of frictional heat as a function of the product of contact area and contact time increases as the set load decreases.

Also in the present embodiment configured as described above,
The drive plates 13a, 13b, ... Are formed in a corrugated shape having a plurality of undulations in the circumferential direction and are set to a plurality of set loads, so that the clearance between the plates and the plate posture are maintained, the clutch transmission torque is raised almost smoothly, etc. It is possible to obtain substantially the same effect as that of the first embodiment described above.

In addition to this, in the present embodiment, the set load of each drive plate 13a, 13b, ... Is set so as to become smaller as the temperature at the arrangement position of each plate 13a, 13b ,. Because
It is possible to increase the frictional heat amount in a portion where the conventional temperature is low, that is, in the low temperature portion to promote the temperature increase, and reduce the frictional heat amount generated in the high temperature portion where the conventional temperature is high to suppress the temperature increase. Therefore, it is possible to reduce the temperature difference between the plates and improve the temperature non-uniformity, and it is possible to suppress and make uniform the friction coefficient characteristics of the facing material 4 in the actual working state. As a result, the shift shock can be prevented for a long period of time.

Further, as shown in FIG. 9, the lubricating oil F interposed between the plates retains an oil film by a so-called wedge effect in a region R narrowed by the swell of the drive plate, as shown by a chain double-dashed line in the figure. It is easy to be done. Therefore, the oil film can be maintained in the vicinity of the wavy convex portion P that is a contact point with the driven plate, and wear due to contact can be more effectively prevented.

In each of the above-described embodiments, a wet clutch accompanied by lubricating oil has been described, but the present invention is not limited to this and can be applied to a dry clutch. Further, in each of the above-described embodiments, the case where the drive plate is formed as a corrugated spring type plate has been described, but the driven plate may be formed as a corrugated spring type plate.

In each of the above embodiments, the case where the multi-disc friction engagement device is applied to the high clutch 136 is illustrated, but the invention is not limited to this, and other multi-disc friction engagement devices such as a forward clutch and a reverse clutch can be used. It can also be applied to a compounding device. Further, it can also be applied to a device which is formally called a multi-disc brake device such as a low and reverse brake.

Further, those skilled in the art can make various additions and changes, such as changing the number of plates and stretching a facing material on the driven plate side.

[0056]

As described above, according to the multi-plate clutch device of the present invention, without using separate and independent spring elements,
Since the plates themselves are provided with springiness, the clearance between the plates and the plate posture can be properly maintained without increasing the number of parts and the weight, and the shift shock can be reduced. The springy plate can be easily obtained by forming a corrugated shape having a plurality of undulations in the direction.

Further, since the set load of the springy plate is set so as to become smaller in accordance with the plate arrangement order, the transmission torque of the clutch can be gradually increased and the clutch can be engaged substantially smoothly.

Further, by setting the set load of the plate having the spring property to become smaller as the temperature at the plate arranging position becomes lower, the frictional heat quantity at the plate, which is apt to become low temperature in the past, is increased, and the relatively high temperature in the conventional plate is relatively high. It is possible to reduce the amount of frictional heat in the plate that tends to become Accordingly, it is possible to improve the temperature nonuniformity between the plates and reduce the shift shock for a long period of time.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view showing a main part of a multi-plate clutch device according to a first embodiment of the present invention.

FIG. 2 is an enlarged external view showing a plate having a spring property.

FIG. 3 is a cross-sectional view showing a contact state at the initial stage of fastening between a plate having a spring property and a counter plate opposite to each other.

FIG. 4 is a cross-sectional view showing a contact state between a plate having a spring property and a counter plate opposite to each other at the final stage of fastening.

FIG. 5 is a characteristic diagram showing a relationship between a plate arrangement position and a set load.

FIG. 6 is a characteristic diagram showing a relationship between a plate arrangement position and a set load.

FIG. 7 is an enlarged sectional view showing a main part of a multi-plate clutch device according to a second embodiment of the present invention.

FIG. 8 is a characteristic diagram showing a relationship between a plate arrangement position and a set load.

FIG. 9 is a cross-sectional view showing a contact state between plates of the wet multi-plate friction engagement device of the present invention.

FIG. 10 is a skeleton diagram of a vertically arranged automatic transmission to which a multi-plate clutch device according to a conventional technique is applied.

FIG. 11 is an external view of a driven plate and a drive plate.

FIG. 12 is a sectional view showing a main part of a multi-plate clutch device according to a conventional technique.

[Explanation of symbols]

 1a, 1b, ... Driven plate 3a, 3b, ... Drive plate 4 Facing material 11a, 11b, ... Driven plate 13a, 13b, ... Drive plate 171 ... Clutch drum 172 ... Clutch hub 173 ... Piston

Claims (6)

[Claims] 1. A multi-plate friction engagement device in which a drive plate and a driven plate, which are respectively movably provided in an axial direction, are alternately arranged, wherein one of the drive plate and the driven plate is a spring. A multi-plate friction engagement device, characterized in that it is formed as a flexible plate. 2. The multi-plate frictional engagement device according to claim 1, wherein the plate having springiness is formed in a corrugated shape having a plurality of undulations in a circumferential direction. 3. The multi-plate friction engagement device according to claim 1, wherein the set load of the plates having each spring property is set to be smaller according to the arrangement order of the plates. 4. The multi-plate according to claim 1, wherein the set load of the plate having each spring property is set so as to become smaller as the temperature at the arrangement position of each plate becomes lower. Friction engagement device. 5. A drum member connected to an input shaft, a plurality of driven plates axially movable on an inner peripheral side of the drum member, a hub member connected to an output shaft, and A plurality of drive plates, which are provided on the outer peripheral side of the hub member so as to be movable in the axial direction, and the drive plates and driven plates, which are alternately arranged on the same axis, are pressed to connect the drive plates. In a multi-disc clutch device including a drive mechanism for driving, one of the drive plates and the driven plate has a corrugated spring property having a plurality of undulations in the circumferential direction and a facing material stretched on both sides. And a set load of the plate having each spring property is set to be smaller according to the arrangement order of each plate. Multi-plate friction engagement device according to claim. 6. A drum member connected to an input shaft, a plurality of driven plates axially movable on an inner peripheral side of the drum member, a hub member connected to an output shaft, A plurality of drive plates, which are provided on the outer peripheral side of the hub member so as to be movable in the axial direction, and the drive plates and driven plates, which are alternately arranged on the same axis, are pressed to connect the drive plates. In a multi-disc clutch device including a drive mechanism for driving, one of the drive plates and the driven plate has a corrugated spring property having a plurality of undulations in the circumferential direction and a facing material stretched on both sides. The load on the plate having each spring property is reduced as the temperature at the position where each plate is arranged becomes lower. Multi-plate friction engagement device, wherein the set to so that.