JPH04277327A - Wet type multi plate tightening device - Google Patents

Abstract

PURPOSE:To provide a wet type multi-plate tightening device which is able to reduce the select lag even when a clearance between plates is set large so as to reduce a drap torque. CONSTITUTION:A group of plates is divided into two toward a piston member via a push member 13, and an intermediate plate 10. Or otherwise, an elastic member is placed between respective primary plates, and elastic modulus of at least one plate is made larger than that of others, and during the initial tightening stage, torque transmission is thus made by a part 11 of the group of plates.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet multi-disc fastening device such as a wet multi-disc clutch or a wet multi-disc brake used in an automatic transmission.

0002

2. Description of the Related Art A conventional wet type multi-plate fastening device is disclosed, for example, in Japanese Patent Application Laid-Open No. 60-263731. FIG. 14 is a sectional view showing the structure of a multi-disc clutch as such a wet-type multi-disc fastening device.

In FIG. 14, 1 is a driven plate;
It engages with the inner periphery of the substantially cylindrical clutch drum 2 and rotates integrally with the clutch drum 2. 3 is a retaining plate, which has a larger axial dimension than the driven plate 1, and a snap ring 4 provided on the clutch drum 2.
Movement to the right in the figure is prohibited.

A drive plate 5 engages with the outer periphery of a clutch hub 6, which is approximately cylindrical and has a smaller diameter than the clutch drum 2, and rotates integrally with the clutch hub 6.

As described above, the driven plate 1, the clutch drum 2, the retaining plate 3, the drive plate 5,
The clutch hub 6 is arranged coaxially, and the driven plates 1 and retaining plates 3 and the drive plates 5 are arranged alternately.

Reference numeral 7 denotes a clutch piston, which is urged to the initial position shown in the figure by a return spring 8. When hydraulic oil is supplied to a pressure chamber 9 formed between the clutch drum 2 and the clutch drum 2, The clutch piston 7 is displaced toward the driven plate 1 side.

[0007] The operation of the multi-disc clutch configured in this manner will be explained. When hydraulic oil is not supplied to the pressure chamber 9, the clutch piston 7 is not displaced toward the driven plate 1, and the driven plate 1 and drive plate 5 are not pressed into contact with each other. Therefore, no torque is transmitted between the clutch drum 2 and the clutch hub 6, and the multi-disc clutch is in an unengaged state.

When hydraulic oil is supplied to the pressure chamber 9, the clutch piston 7 is displaced toward the driven plate 1, and the driven plate 1 and the drive plate 5 are brought into pressure contact with the retaining plate 3. Therefore clutch drum 2
Torque is transmitted between the clutch hub 6 and the clutch hub 6, and the multi-disc clutch becomes engaged.

[0009]

However, when such a conventional wet multi-plate fastening device is not fastened, lubricating oil is present between the driven plate 1 and the drive plate 5. The structure was such that drag torque (dragging) could occur due to the viscosity of the material. The magnitude of the drag torque increases as the clearance C between the driven plate 1 and the drive plate 5 decreases, as shown in FIG.
Below that, the drag torque becomes significantly large. Therefore, in order to reduce drag torque, it is effective to make the clearance C larger than C0.

However, if the clearance C is set large, the stroke of the clutch piston 7 when bringing the driven plate 1 and the drive plate 5 into pressure contact increases.
Because the time it takes for the wet multi-plate fastening device to go from the unfastened state to the engaged state is longer, the time lag (select lag) between when the shift lever is operated and when the wet multi-plate fastening device goes into the engaged state increases. There was a problem.

An object of the present invention is to provide a wet multi-plate fastening device that can reduce select lag even when the clearance between plates is set large to reduce drag torque.

0012

[Means for solving the problem] In order to solve the above problem,
In the invention according to claim 1, a plurality of first plates that engage with and rotate integrally with the first transmission member, and are arranged coaxially with the first transmission member and alternately with the first plates; , a plurality of second plates that engage with a second transmission member and rotate integrally; a piston member that presses a plate group consisting of the plurality of first plates and a plurality of second plates; and a piston member that presses the plate group. An interface that is divided into two in the axial direction into a primary fastening plate group adjacent to the member and a secondary fastening plate group spaced apart from the piston member, and that engages with the first transmission member or the second transmission member and rotates integrally. an intermediate plate, and at least when the primary fastening plate group is fastened, a pressing member that presses a plate adjacent to the intermediate plate among the primary fastening plate group in the direction of the piston member;
It is characterized in that it is provided between the primary fastening plate group and the first transmission member or the second transmission member.

In the invention as claimed in claim 2, the plurality of first plates and the plurality of second plates are arranged alternately and concentrically;
a piston member that presses the plate, and the first
In a wet multi-plate fastening device in which elastic members are interposed between the plates, at least one of the elastic members is
The elastic modulus of one elastic member is smaller than the elastic modulus of the other elastic members.

[0014]

[Operation] In the invention described in claim 1, as the piston member is displaced, the primary fastening plate group is first brought into pressure contact between the piston member and the pressing member, and the torque is transmitted by the primary fastening plate group. It is done. When the piston member is still displaced while compressing the pressing member, the primary fastening plate group is pressed against the secondary fastening plate group via the intermediate plate, so that the primary fastening plate group and the secondary fastening plate group are Torque is transmitted by the plate group consisting of the intermediate plate and the intermediate plate.

In the invention according to claim 2, when the elastic member having a smaller elastic modulus than other elastic members is compressed by the displacement of the piston member, the first plate located on both sides of the elastic member and the first plate are compressed. A second plate located between the plates is pressed into contact with each other, and torque is transmitted by these plates. Next, when the piston member is displaced while compressing another elastic member, all the first plates and all the second plates are brought into pressure contact and torque is transmitted.

[0016]

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings. Note that the same components as those in the prior art are given the same reference numerals, and the description thereof will be omitted.

FIG. 1 is a diagram showing the configuration of a first embodiment of the present invention, and is a sectional view of a multi-disc clutch as a wet-type multi-disc fastening device. FIG. 2 also shows the clutch piston 7 as a piston member and the driven plate 1 as a first plate.
FIG. 3 is a schematic diagram showing the positional relationship among a retaining plate 3, a drive plate 5 as a second plate, an intermediate plate 10, and a dish plate 13 as a pressing member.

The driven plates 1, retaining plates 3, and drive plates 5 are arranged alternately and concentrically to form a plate group.

A clutch drum 2 is located between the plate groups.
An intermediate plate 10 is provided which engages with. The plate group is divided into a primary fastening plate group 11 adjacent to the clutch piston 7 and a secondary fastening plate group 12 spaced apart from the clutch piston 7 by the intermediate plate 10.

13 is a dish plate, and the intermediate plate 1 is connected by a snap ring 14.
Displacement in the direction of 0 is prohibited.

When the multi-disc clutch is not engaged, the clutch piston 7 and the primary engagement plate group 11 are spaced apart from each other by a distance a, and the primary engagement plate group 11 is spaced apart from each other from the clutch piston 7 side by b, They are provided at intervals of c. Furthermore, the distance between the end of the dish plate 13 on the clutch piston 7 side and the primary fastening plate group 11 is k.
The end portion of the dish plate 13 on the clutch piston 7 side and the intermediate plate 10 are provided with a distance l between them. Furthermore, the intermediate plate 10 and the secondary fastening plate group 12
are provided with a distance d between them, and the secondary fastening plate group 12 is spaced e, f from the intermediate 10 side.
, g, h, i.

Here, the compression margin j of the dish plate 13 is designed to satisfy the relationship: j>d+e+f+g+h+i+l.

Next, regarding the operation of this embodiment, FIGS. 2 and 3
Explain with reference to. Here, FIG. 3 is a characteristic diagram of the transmission capacity T of the multi-disc clutch with respect to the stroke x of the clutch piston 7.

When hydraulic oil is not supplied to the pressure chamber 9, the clutch piston 7 does not move toward the driven plate 1, so the driven plate 1, retaining plate 3, drive plate 5, and intermediate plate 10 are spaced apart from each other. Therefore, no torque is transmitted between the clutch drum 2 and the clutch hub 6.

Hydraulic oil is supplied to the pressure chamber 9, the clutch piston 7 is displaced toward the driven plate 1, and the stroke x of the clutch piston 7 becomes x11, that is, a+b+c.
When +k is reached, the primary fastening plate group 11 is brought into contact with the dish plate 13. When the clutch piston 7 is further displaced, the dish plate 13 is prohibited from being displaced in the direction of the intermediate plate 10 by the snap ring 14, so the primary fastening plate group 1
1 deforms the dish plate 13. At this time, due to the repulsive restoring force generated in the dish plate 13,
The primary fastening plate group 11 is pressed against each other between the clutch piston 7 and the dish plate 13, and torque transmission between the clutch drum 2 and the clutch hub 6 is started.

[0026] The clutch piston 7 is connected to the driven plate 1.
When the primary fastening plate group 11 is further displaced to the side by l, the primary fastening plate group 11 comes into contact with the intermediate plate 10. When the clutch piston 7 is further displaced and the stroke reaches x12, that is, a+b+c+k+l+d+e+f+g+h+i, the primary engagement plate group 11 is brought into pressure contact with the secondary engagement plate group 12 via the intermediate plate 10, and engagement of the multi-plate clutch is completed. .

FIG. 4 shows the characteristics of the working oil pressure P acting on the pressure chamber 9 and the transmission capacity T. Generally, the transmission capacity T increases in proportion to the number of plates, so while torque is being transmitted by the primary fastening plate group 11 and the secondary fastening plate group 12, only the primary fastening plate group 11 While torque is being transmitted by
is large, and the rate of increase of the transmission capacity T with respect to the working oil pressure P differs after the working oil pressure P1. The effects of this embodiment are as shown below. First, in this embodiment, since torque is transmitted when the stroke of the clutch piston 7 reaches x11, torque is transmitted only when all driven plates 1 and drive plates 5 are brought into pressure contact. Compared to the prior art, the stroke x of the clutch piston 7 required until torque is transmitted is smaller. Therefore, even if the clearance C between the plates is set large in order to reduce drag torque, it is possible to reduce the select lag compared to the prior art.

Furthermore, as shown in FIG. 4, the rate of increase in the transmission capacity T as the working oil pressure P increases is smaller in the range below the working oil pressure P1 than in the range above P1. When the multi-plate fastening device is used in combination with the duty hydraulic control device, it becomes possible to finely control the region where the transmission capacity T is low.

In this embodiment, the intermediate plate 10 is provided to engage with the clutch drum 2, and the dish plate 13 is provided between the primary fastening plate group 11 and the clutch drum 2. However, the present invention is not limited thereto. That is, the intermediate plate 10 may be provided to engage with the clutch hub 6, or the dish plate 13 may be provided between the primary fastening plate group 11 and the clutch hub 6.

Next, a second embodiment of the present invention will be described. FIG. 5 is a diagram showing the configuration of the second embodiment, and is a sectional view of a multi-disc clutch as a wet-type multi-disc fastening device. Further, FIG. 6 is a schematic diagram showing the positional relationship between the plate group and the intermediate plate 10 and the coil spring 15 as a pressing member in place of the dish plate 13.

In this embodiment, the driven plate 1 adjacent to the intermediate plate 10 of the primary fastening plate group 11 is prohibited from being displaced toward the clutch piston 7 by the snap ring 16. A pre-compressed coil spring 15 is provided between the plate 1 and the snap ring 14.

Furthermore, the dimension m of the drive plate 5 of the primary fastening plate group 11 is m>n+l+d+e+f+g+h+ where n is the axial dimension of the snap ring 16.
i, and when the multi-plate clutch is engaged, the clutch piston 7 and the adjacent driven plate 1
The fastening can be completed by the time the snap ring 16 comes into contact with the snap ring 16. The other configurations are the same as in the first embodiment.

The operation of this embodiment will be explained with reference to FIGS. 6 and 7. Here, FIG. 7 is a characteristic diagram of the transmission capacity T of the multi-disc clutch with respect to the stroke x of the clutch piston 7 in this embodiment.

When hydraulic oil is not supplied to the pressure chamber 9, the multi-disc clutch is in an unengaged state, similar to the first embodiment.

When hydraulic oil is supplied to the pressure chamber 9 and the clutch piston 7 is displaced toward the driven plate 1, and the stroke reaches x21, that is, a+b+c, the primary fastening plate group 11 comes into contact with the coil spring 15. Since the coil spring 15 has been compressed in advance and has a repulsive restoring force, the primary fastening plate group 11 is immediately fastened between the clutch piston 7 and the coil spring 15, and the clutch drum 2 and the clutch hub 6 are fastened together. Torque transmission begins between the two.

When the clutch piston 7 is further displaced, 1
The next engagement plate group 11 is displaced while compressing the coil spring 15, and the transmission capacity T of the multi-disc clutch gradually increases. And the stroke is x22 or a+b+c
When +l+d+e+f+g+h+i is reached, the primary engagement plate group 11 comes into contact with the intermediate plate 10, and then comes into pressure contact with the secondary engagement plate group 12 via the intermediate plate 10, completing engagement of the multi-disc clutch.

The characteristics of the hydraulic pressure P acting on the pressure chamber 9 and the transmission capacity T are the same as in the first embodiment.

In this embodiment, the primary fastening plate group 11 is fastened between the pre-compressed coil spring 15 and the clutch piston 7, so that in addition to the effects achieved by the first embodiment, the effects shown in FIG. As shown in Fig. 7, there is an effect that a constant and stable transmission capacity can be obtained in the initial stage of fastening.

Next, a third embodiment of the present invention will be described. FIG. 8 is a diagram showing the configuration of the third embodiment, and is a sectional view of a multi-disc clutch as a wet-type multi-disc fastening device.

In this embodiment, a hydraulic piston 17 is provided as a pressing member in place of the coil spring 15, and the clutch drum 2 is provided with a passage 18 for supplying hydraulic oil to the hydraulic piston 17. There is. Here, it is assumed that appropriate hydraulic fluid is introduced into the hydraulic piston 17 from a control valve (not shown) provided in the automatic transmission. The other configurations are the same as the second embodiment.

The operation of this embodiment is similar to that of the second embodiment. That is, in this embodiment, hydraulic oil is introduced into the hydraulic piston 17 through the passage 18, and the driven plate 1 adjacent to the hydraulic piston 17 is pressed toward the clutch piston 7 side. Therefore, as in the second embodiment, as the clutch piston 17 is displaced, the primary engagement plate group 11 is immediately engaged between the clutch piston 7 and the hydraulic piston 17.

In this embodiment, the coil spring 1
By using the hydraulic piston 17 instead of the hydraulic piston 17, in addition to the effect achieved by the second embodiment, a stable pressing force can always be obtained on the driven plate 1 adjacent to the hydraulic piston 17. It is something.

Next, a fourth embodiment of the present invention will be described. FIG. 9 is a diagram showing the configuration of the fourth embodiment, and is a sectional view of a multi-disc clutch as a wet-type multi-disc fastening device. Further, FIG. 10 shows the plate group and elastic members 19 and 2 as pressing members.
0, 21, and 22. FIG.

In this embodiment, the intermediate plate 10, the dish plate 13 as a pressing member, the coil spring 15, the hydraulic piston 17, the snap rings 14, 16, and the passage 18 are not provided.

Further, elastic members 19, 20, 21, and 22 are provided between the driven plates 1, respectively. Among these, the elastic coefficient k2 of the elastic members 20, 21, 22,
Since k3 and k4 are each equal and larger than the elastic coefficient k1 of the elastic member 19, the elastic members 19, 20, 21,
The relationship between the displacement amount and repulsive force when 22 is compressed is the 11th
As shown in the figure. The two driven plates 1 adjacent to the elastic member 19 and the drive plate 5 sandwiched between these two driven plates 1 form one
A secondary fastening plate group 11 is constituted, and the other driven plates 1, drive plates 5, and retaining plates 3 constitute a secondary fastening plate group 12.

Here, the clutch piston 7 and the driven plate 1 adjacent to the clutch piston 7 are separated by a distance a.
The driven plate 1, the retaining plate 3, and the drive plate 5 are provided at intervals b, c, d, e, f, from the clutch piston 7 side.
g, h, and i. The other configurations are the same as those of the first to third embodiments.

FIGS. 10 and 12 regarding the operation of this embodiment
Explain with reference to. Here, FIG. 12 shows the transmission capacity T of the multi-disc clutch with respect to the stroke x of the clutch piston 7.
FIG.

When hydraulic oil is not supplied to the pressure chamber 9, the multi-disc clutch is in an unengaged state, similar to the first to third embodiments.

When hydraulic oil is supplied to the pressure chamber 9 and the clutch piston 7 is displaced toward the driven plate 1 and begins to press the plate group, the elastic members 19, 20, 21, provided between the driven plates 1, 22 is also pressed,
Among these, the elastic member 19 having the smallest elastic modulus is compressed, and a repulsive force is generated in the elastic members 20, 21, and 22. When the stroke of the clutch piston 7 reaches x31, that is, a+b+c, the primary fastening plate group 11 is pressed against each other between the clutch piston 7 and the elastic member 20. As a result, torque transmission between the clutch drum 2 and the clutch hub 6 is started.

Next, when the clutch piston 7 is further displaced, the elastic members 20, 21, and 22 are also compressed, and when the stroke reaches x32, that is, a+b+c+d+e+f+g+h+i, the primary fastening plate group 11 is integrally pressed against the secondary fastening plate group 12. Ru. This completes the engagement of the multi-disc clutch.

The characteristics of the hydraulic pressure P acting on the pressure chamber 9 and the transmission capacity T in this embodiment are as shown in FIG. 3, as in the first embodiment.

In this embodiment, unlike the first to third embodiments, there is no need to provide the intermediate plate 10, and the axial dimension does not increase.
In addition to the effects achieved by the embodiments, there is an effect of excellent space efficiency. Furthermore, since elastic members 19, 20, 21, and 22 are provided between the driven plates 1, the driven plates 1
It is possible to secure the clearance C between the drive plate 5 and the drive plate 5, and there is also the effect that the drag torque can be reliably reduced.

Note that in this embodiment, the elastic member 19
Although the elastic coefficient k1 of the elastic members 20, 21, and 22 is set smaller than the elastic coefficients k2, k3, and k4 of the elastic members 20, 21, and 22, arbitrary transmission capacity T characteristics can be obtained by changing the relationship between the elastic coefficients k1, k2, k3, and k4. be able to. For example, if the elastic modulus of the elastic members 19, 20, 21, 22 is k1<k2<
If k3<k4 is set, the plate groups are sequentially engaged from the clutch piston 7 side, so as shown in FIG.
There are four stages with P2 and P3 as boundaries.

[0054]

As described above, in the invention as claimed in claim 1, the plate group consisting of the first plate and the second plate is connected to the primary fastening plate group via the intermediate plate. Secondary fastening plate group 2
Since the torque is transmitted by the primary fastening plate group in the initial stage of fastening, it is possible to reduce select lag compared to conventional technology even when the clearance between plates is set large to reduce drag torque. can.

Further, in the invention as claimed in claim 2, elastic members are interposed between the first plates, and the elastic modulus of at least one of the elastic members is higher than the elastic modulus of the other elastic members. By setting it small, torque is transmitted by the adjacent plate group via the elastic member with a small elastic modulus in the initial stage of fastening, so in addition to the effect of the invention as claimed in claim 1, good space efficiency can be obtained. In addition, since the elastic member secures the clearance between the plates when they are not engaged, drag torque can be reduced more reliably.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of a multi-disc clutch as a wet multi-disc fastening device in a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing the positional relationship between a plate group, an intermediate plate, and a dish plate in the first embodiment.

FIG. 3 is a characteristic diagram of the transmission capacity T of the multi-disc clutch with respect to the stroke x of the clutch piston in the first embodiment.

FIG. 4 is a characteristic diagram showing the relationship between the working oil pressure P and the transmission capacity T in the first embodiment.

FIG. 5 is a sectional view showing the structure of a multi-disc clutch in a second embodiment.

FIG. 6 is a schematic diagram showing the positional relationship between the plate group, intermediate plates, and coil springs.

FIG. 7 is a characteristic diagram showing the relationship between the transmission capacity T of the multi-disc clutch and the stroke x of the clutch piston in the second embodiment.

FIG. 8 is a sectional view showing the structure of a multi-disc clutch in a third embodiment.

FIG. 9 is a sectional view showing the structure of a multi-disc clutch in a fourth embodiment.

FIG. 10 is a schematic diagram showing the positional relationship between the plate group and the elastic member.

FIG. 11 is a characteristic diagram showing the relationship between the amount of compressive displacement of the elastic member and the repulsive force.

FIG. 12 is a characteristic diagram showing the relationship between the transmission capacity T of the multi-disc clutch and the stroke x of the clutch piston in the fourth embodiment.

[Fig. 13] Working oil pressure P and transmission capacity T in the fourth embodiment
Another characteristic diagram showing the relationship with.

FIG. 14 is a sectional view showing the structure of a multi-disc clutch in the prior art.

FIG. 15 is a characteristic diagram showing the relationship between drag torque and clearance between plates.

[Explanation of symbols] 1 Driven plate (first plate) 2 Clutch drum (first transmission member) 5 Drive plate (second plate) 6 Clutch hub (second transmission member) 7 Clutch piston (piston member) 11 Primary connection Plate group 12 Secondary fastening plate group 13 Dish plate (pressing member) 15 Coil spring (pressing member) 17 Hydraulic piston (pressing member) 19, 20, 21, 22 Elastic member

Claims (2)

[Claims] 1. A plurality of first plates that engage with and rotate integrally with a first transmission member, a plurality of first plates that are arranged coaxially with the first transmission member and alternately with the first plates, and a second transmission member that is arranged coaxially with the first transmission member and alternately with the first plates; a plurality of second plates that engage with the member and rotate integrally with the member; a piston member that presses a plate group consisting of the plurality of first plates and the plurality of second plates; and a piston member that brings the plate group adjacent to the piston member. an intermediate plate that is divided into two in the axial direction into a primary fastening plate group and a secondary fastening plate group that is spaced apart from the piston member, and that engages with the first transmission member or the second transmission member and rotates integrally; and a pressing member that presses a plate adjacent to the intermediate plate among the primary fastening plate groups in the direction of the piston member at least when the primary fastening plate groups are fastened. A wet multi-plate fastening device, characterized in that it is provided between the first transmission member or the second transmission member. Claim 2: A plurality of first parts arranged alternately and concentrically.
A wet multi-plate fastening device comprising a plate, a plurality of second plates, and a piston member that presses the plurality of first plates and the plurality of second plates, and in which an elastic member is interposed between each of the first plates. In the wet multi-plate fastening device, the elastic modulus of at least one of the elastic members is smaller than the elastic modulus of the other elastic members.