JPH05141445A - Multiple-plate clamping element - Google Patents

Abstract

PURPOSE:To prevent uneven contact of a driving plate with a driven plate and increase of piston stroke, by means of a stepped retainer in which thickness a spline connection side is made thinner while a plate support side thicker. CONSTITUTION:A stepped retainer 7 has a high bending rigidity because its spline connection side is composed of a thinner portion 7a while its plate support side is composed of a thicker portion 7b. The rear side of the thinner portion 'a has a fixed shape, and is in contact with and is supported by a spline stepped portion 8c of a stepped spline 8 having a high supporting rigidity. When the stepped retainer 7 receives a clamping load applied from a clutch piston at the time of clamping, the stepped retainer 7 shows almost no stroke in the axial direction and its inclination can be minimized. Consequently, uneven contact of a driving plate 2 and a driven plate 4 at the time of clamping and increase of piston stroke can be prevented with a simple construction composed of a small number of parts, requiring no snap rind.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-plate fastening element applied as a clutch or a brake to an automatic transmission or the like.

[0002]

2. Description of the Related Art As a first conventional example of a fastening load supporting structure for a multi-plate clutch for an automatic transmission, for example, as shown in FIG. 4, a structure in which a straight retainer having a constant thickness and a snap ring are combined is generally used. Known to.

As a conventional example 2 of a fastening load supporting structure for a multi-plate clutch for an automatic transmission, for example, as shown in FIG.
A structure is known in which a stepped retainer having a different thickness and a snap ring are combined (Japanese Patent Laid-Open No. 2-221719).
(See the official gazette).

[0004]

However, in the multi-plate clutch for an automatic transmission according to the prior art example 1, as a single unit, a fastening load support in which a straight retainer having a low bending rigidity and a snap ring having a low supporting rigidity are combined is used. Because of the structure, as shown in FIG. 5, when the clutch is fastened by the fastening piston, the straight retainer is bent and deformed,
In addition, the snap ring is tilted, and only the outer circumferences of the drive plate and the driven plate have a high surface pressure, resulting in a one-sided contact state. The piston stroke increases as the straight retainer moves in the axial direction.

Due to this one-sided contact, the μ-V characteristic, which is the characteristic of the friction coefficient and the fastening rotation speed, deteriorates, and the durability also deteriorates. Further, as the piston stroke increases, the rising gradient of the clutch engagement capacity becomes gentle as shown in FIG. 6 and the timing of completely engaging the clutch is delayed, and as shown in FIG. Prolongation occurs during the phase.

On the other hand, the multi-plate clutch for an automatic transmission according to the second conventional example has a fastening load supporting structure in which a step retainer having a high bending rigidity and a snap ring having a low supporting rigidity are combined as a single unit. As shown in FIG. 9, when the clutch is fastened by the fastening piston, the bending deformation of the stepped retainer is almost eliminated, but as shown in FIG.
The snap ring is tilted, and one-sided contact and piston stroke are not corrected as expected.

The present invention has been made in view of the above problems, and in a multi-plate fastening element that receives a fastening load by a retainer, while having a simple fastening load supporting structure with a small number of parts, a drive plate at the time of fastening. Another object is to prevent uneven contact of the driven plate and increase in piston stroke.

[0008]

In order to solve the above problems, in the multi-plate fastening element of the present invention, a fastening load supporting structure is formed by a combination of a stepped retainer and a stepped spline.

That is, the drive plate is spline-coupled to one of the hub and the drum, and the driven plate is spline-coupled to the other, the fastening pistons are arranged at one end of the alternately arranged plates, and the retainer is provided at the other end. In the multi-plate fastening element in which is arranged, the retainer is a stepped retainer in which a step portion is formed at a portion where the thickness changes by making the spline coupling side a thin portion and the plate supporting side a thick portion, and the spline Is a stepped spline in which a spline step portion that contacts the back surface of the thin portion of the stepped retainer is formed.

[0010]

[Operation] When the fastening piston is stroked and fastened, the piston stroke shortens the distance between the drive plate and the driven plate to make contact, and as the fastening force increases, the relative rotation of both plates decreases.
Finally, the fastening state without relative rotation is reached.

The fastening load applied from the fastening piston at the time of fastening is received by the stepped retainer. Even if the stepped retainer receives the fastening load, the stepped retainer has a high bending rigidity as a single unit. However, since the stepped retainer is supported by the spline step portion having high support rigidity, there is almost no stroke in the axial direction of the stepped retainer, and the inclination thereof can be suppressed to be small.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

First, the structure will be described.

FIG. 1 is a sectional view showing a multi-plate clutch for an automatic transmission (an example of a multi-plate fastening element) of the embodiment, and FIG. 2 is a main part cross-sectional view showing a retainer portion of the embodiment clutch.

The multi-plate clutch A for an automatic transmission of the embodiment is
As shown in FIG. 1, a plurality of drive plates 2 are splined to a clutch hub 1, a plurality of driven plates 4 are splined to a clutch drum 3, and a wave spring 5 is interposed between adjacent driven plates 4 and 4. The clutch piston 6 is arranged at one end,
A stepped retainer 7 is arranged at the other end.

In the stepped retainer 7, a step portion 7c is formed at a portion where the thickness changes by forming the thin portion 7a on the spline coupling side and the thick portion 7b on the plate supporting side.

The spline on the side of the driven plate 4 is a stepped spline 8. The stepped spline 8
Is a low step portion 8a to which the driven plate 4 is coupled, a high step portion 8b having a height close to the step portion 7c, and a spline formed at a portion changing from the low step portion 8a to the high step portion 8b. And a step portion 8c, and this spline step portion 8c
Is in contact with the back surface of the thin portion 7a of the stepped retainer 7.

A facing material 9 is attached to both sides of the drive plate 2.

Next, the operation will be described.

First, when the clutch is disengaged, the space between the adjacent driven plates 4 and 4 is maintained by the wave spring 5. When the clutch piston 6 is stroked and engaged, the piston stroke shortens the gap between the drive plate 2 and the driven plate 4 and makes contact with each other.
The relative rotation of No. 4 becomes small, and finally the fastening state without relative rotation is reached.

The fastening load applied from the clutch piston 6 at the time of this fastening is received by the stepped retainer 7. However, even if the stepped retainer 7 receives the fastening load, the stepped retainer 7 is provided for the following reason. There is almost no stroke in the axial direction, and the inclination can be kept small.

The first reason is that the stepped retainer 7 has a thin portion 7a on the spline coupling side and a thick portion 7b on the plate supporting side.
Therefore, the bending rigidity as a single unit is high.

The second reason is that the thin portion 7 of the stepped retainer 7 is
The back surface of a is in contact with and supported by the spline step portion 8c of the stepped spline 8 having a fixed shape and high support rigidity.

Further, since the stepped retainer 7 is used, the spline 8 of the clutch drum 3 is used, for example, when the conventional clutch B is provided adjacently as shown in FIG.
The gap between the stepped retainer 7 and the snap ring SR is
Even if the spline teeth (higher step portion 8b) have a size sufficient to ensure the rigidity, it is possible to prevent the increase in the axial length dimension of the automatic transmission while ensuring the rigidity of the stepped retainer 7.

As described above, in the embodiment, in the multiple disc clutch A for an automatic transmission which receives the fastening load by the retainer, the fastening load supporting structure is formed by the combination of the stepped retainer 7 and the stepped spline 8. Therefore, it is possible to prevent the drive plate 2 and the driven plate 4 from hitting each other at the time of clutch engagement and prevent the piston stroke from increasing while using a simple fastening load support structure that does not require a snap ring and has a small number of parts.

As a result, the μ-V characteristic, which is the characteristic of the friction coefficient and the engagement rotational speed, is maintained constant, and the clutch durability is also improved. Also, by preventing the piston stroke from increasing, the rising gradient of the clutch engagement capacity becomes steep at the time of engagement, the timing delay of completely engaging the clutch is prevented, and the extension of the torque phase is prevented during the transition period of the shift. can do.

As shown in FIG. 3, the multi-plate clutch A of the embodiment is applied to a clutch having a clutch piston 6 on the front side in the assembling direction (arrow direction) and a retainer 7 on the rear side. Then, it becomes easy to process the spline step portion 8c of the clutch drum 3. At this time, since there is no inclination of the snap ring (see FIG. 10) as shown in Conventional Example 2, the stepped retainer 7 is stably supported, and the retainer stepped portion 7c and the spline stepped portion 8c are meshed with each other. Therefore, the inclination of the stepped retainer 7 is also reliably prevented.

Incidentally, as shown in FIG. 2, the spline step portion 8c.
When the drive plate 2 and the outer peripheral portion of the drive plate 2 overlap (α), the load at the time of clutch engagement is directly transmitted to the clutch drum 3, and the load on the stepped retainer 7 is reduced, so that the stepped retainer is made thinner. It becomes possible.

Although the embodiments have been described above with reference to the drawings, the specific configuration is not limited to the embodiments, and modifications and additions within the scope of the present invention are included in the present invention. Be done.

For example, in the embodiment, the example of application to the multi-plate clutch for the automatic transmission is shown, but it can be applied to the multi-plate clutch applied for other purposes, and as the multi-plate brake. It can also be applied.

Further, the clutch drum in which the stepped spline is formed may be made of a light alloy such as aluminum for the purpose of weight reduction, and the step retainer may be made of iron or the like for suppressing wear.

[0032]

As described above, according to the present invention, in the multi-plate fastening element that receives the fastening load by the retainer, the fastening load supporting structure is formed by the combination of the stepped retainer and the stepped spline. It is possible to obtain an effect that it is possible to prevent one-sided contact between the drive plate and the driven plate and an increase in piston stroke at the time of fastening, while using a simple fastening load supporting structure with less number of turns.

[Brief description of drawings]

FIG. 1 is a sectional view showing a multiple disc clutch for an automatic transmission according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main portion showing a retainer portion of an example clutch.

FIG. 3 is a cross-sectional view showing a state in which the example clutch is assembled with another clutch in an automatic transmission.

FIG. 4 is a vertical sectional side view showing a multi-plate clutch for an automatic transmission of Conventional Example 1.

FIG. 5 is an explanatory view of a fastening operation of the multiple disc clutch for the automatic transmission of Conventional Example 1.

FIG. 6 is a characteristic diagram of clutch engagement capacity in Conventional Example 1.

FIG. 7 is a characteristic diagram of an automatic transmission output shaft torque at the time of shifting in Conventional Example 1.

FIG. 8 is a vertical cross-sectional side view showing a multi-plate clutch for an automatic transmission of Conventional Example 2.

FIG. 9 is an explanatory view of a fastening operation of a multiple disc clutch for an automatic transmission of Conventional Example 2.

FIG. 10 is an operation explanatory diagram of a stepped retainer and a snap ring of Conventional Example 2 at the time of fastening.

[Explanation of Codes] A Multi-plate clutch for automatic transmission (multi-plate fastening element) 1 Clutch hub (hub) 2 Drive plate 3 Clutch drum (drum) 4 Driven plate 6 Clutch piston (fastening piston) 7 Step retainer 7a Thin section 7b Thick section 7c Step section 8 Stepped spline 8c Spline step section

Claims (1)

[Claims] 1. A drive plate is spline-coupled to one of a hub and a drum, and a driven plate is spline-coupled to the other, and a fastening piston is disposed at one end of both plates alternately arranged, and a retainer is provided at the other end. In the multi-plate fastening element in which is arranged, the retainer is a stepped retainer in which a step portion is formed in a portion where the thickness changes by making the spline coupling side a thin portion and the plate support side a thick portion, and the spline To
A multi-plate fastening element, characterized in that it is a stepped spline in which a spline step portion that contacts the back surface of the thin portion of the stepped retainer is formed.