JPH11230197A - Wet clutch device - Google Patents

Abstract

(57) [Summary] [Problem] After making sure and quick release operation possible,
Provided is a wet clutch device which can prevent troubles with a simple structure and can be manufactured at low cost. An elastic portion (11b), which is continuous with the clutch plate (11) in a circumferential direction, is curved, so that a piston (5) is formed.
When the pressing force of the clutch disk 13 is released, the elastic portion 11b returns to its original shape due to its own elasticity,
3b, as a result, the clutch can be released reliably and promptly, and the elastic portion 11b is provided only by forming the clutch plate 11 itself in a curved shape.
The structure of the clutch device is not complicated at all.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet clutch device for performing engagement / disengagement operations in hydraulic oil.

[0002]

2. Description of the Related Art As a wet clutch device of this type, there is, for example, a device used for an automatic transmission of a vehicle. As is well known, a sun gear, a planetary carrier and the like constituting a planetary gear in association with an engagement / disengagement operation are known. The automatic transmission is switched to a desired gear by permitting or restricting the movement. Generally, this type of wet clutch device is liable to cause clutch release failure, and if the clutch plate and the clutch disk remain stuck despite the release operation, the shift is directly connected to the gear shift failure, and the release is difficult. In a complete state, there is a problem that heat is generated by sliding contact between the clutch plate and the clutch disk, causing a clutch burn or an increase in drag torque cross.

As a countermeasure, Japanese Utility Model Application Laid-Open No. 2-112
As described in Japanese Patent Publication No. 28, there is a wet clutch device in which a plurality of leaf springs are circumferentially riveted on the surface of a clutch disc and are actively separated from a clutch plate by the urging force of the leaf springs. Proposed.

[0004]

However, in the wet clutch device described in the prior art, the leaf spring is riveted, so that the structure becomes complicated, and troubles such as loss of the function of the leaf spring due to dropping of the rivet are possible. There was sex.
In particular, in the case of using a large number of clutch disks, such as an automatic transmission, the number of leaf springs is inevitably increased. As a result, a rise in manufacturing cost is not negligible.

Further, since the leaf spring needs to be riveted at a position avoiding the friction material of the clutch disk, the area of the clutch disk is increased and the area of the corresponding clutch plate is also increased. It cannot be used in automatic transmissions and the like that require space saving in units of millimeters. The object of the present invention is to make it possible to release operation reliably and promptly, to prevent troubles with a simple structure, to manufacture it at low cost, and to save the space by preventing the area of the clutch disk and the like from expanding. It is an object of the present invention to provide a wet clutch device which can sufficiently meet the requirements of the above.

[0006]

In order to achieve the above object, according to the present invention, at least one of a first friction plate and a second friction plate which are alternately arranged is displaced in the thickness direction. Because the elastic portion is curved, the elastic portion bends and becomes flat when the pressing force is applied in the axial direction by the pressing operation means, and returns to the original shape due to its own elasticity when the pressing force is released. It returns and separates from the friction plate on the other side, and as a result, the clutch is reliably and promptly released. In addition, since the elastic portion is provided only by bending the friction plate itself, the structure of the clutch device is not complicated at all, and the friction plate itself functions as the elastic portion. Expansion can be prevented.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a wet multi-plate clutch device used for an automatic transmission of a vehicle will be described below. Although not shown, the automatic transmission includes a plurality of sets of planetary gears, and a plurality of sets of clutch devices and brake devices.These clutch devices and brake devices change the planetary gears according to the switching operation of the solenoid valve. The movement of the sun gear, the planetary carrier and the like is allowed or restricted, and as a result, the automatic transmission can be switched to a desired gear.

FIG. 1 shows one of the above-mentioned clutch devices. This clutch device plays a role in transmitting the rotation of an input shaft 1 to a clutch hub 2 connected to a sun gear (not shown). In the drawing, a clutch housing 3 is integrally formed at the right end of the input shaft 1, and this clutch housing 3 has a cylindrical shape that opens to the right with the axis L of the input shaft 1 as the center. 2 are arranged. An annular cylinder 4 is formed in the inner part of the clutch housing 3, and a piston 5 having a corresponding shape is arranged in the cylinder 4 so as to be movable in the direction of the axis L. In this embodiment, the input shaft 1
Function as a first member, the clutch hub 2 functions as a second member, and the cylinder 4 and the piston 5 function as pressing operation means.

A groove 5 is provided at a position substantially opposing the entire circumference of the inner peripheral surface 5b of the piston 5 and the inner peripheral surface 4b of the cylinder 4.
d, 4d are provided, and the inner seal 6 is provided in the grooves 5d, 4d.
Is inserted. Grooves 5e, 4e are provided at positions substantially opposite to the entire circumference of the outer peripheral surface 5c of the piston 5 and the outer peripheral surface 4c of the cylinder 4, respectively. The outer seal 7 is inserted into the grooves 5e, 4e. The oil pressure chamber 8 is kept oil-tight by these seals 6 and 7.

An ATF (Automatic Transmission Fluid) is supplied into the hydraulic chamber 8 through an oil passage 9 of the input shaft 1 in accordance with a switching operation of a solenoid valve (not shown). Acts in the direction to move to the right. Here, the inner seal 6 and the outer seal 7 have a so-called retraction function of returning the piston 5 to the original position on the left side in addition to maintaining the oil tightness. The pistons 6 and 7 are elastically deformed and return the piston 5 to the left original position by its own elasticity as the oil pressure decreases. The operation of the seals 6 and 7 is very general.

A piston 5 is provided in the clutch housing 3.
An annular stopper surface 10 is formed opposite to the pressing surface 5a at a predetermined interval, and four annular clutch plates 11 are provided between the stopper surface 10 and the pressing surface 5a of the piston 5 along the axis L. It is arranged in the direction. FIG.
As shown in FIG. 5, protrusions 11a are formed at eight equally-spaced portions on the outer periphery of each clutch plate 11, and these protrusions 11a are formed.
Are engaged with the spline grooves 12 in the clutch housing portion 3, and the rotation of each clutch plate 11 with respect to the input shaft 1 is restricted while the movement in the direction of the axis L is permitted.

Stopper surface 10 of each clutch plate 11
1 (right side in FIG. 1), friction material 1
An annular clutch disc 13 with 3b is arranged,
Each clutch disc 13 has a projection 13 formed on the inner circumference.
a into the spline groove 14 of the clutch hub 2,
The rotation of the clutch hub 2 is restricted while the movement in the direction of the axis L is allowed. That is, the clutch plates 11 and the clutch disks 13 are alternately arranged,
When the piston 5 moves to the right in FIG. 1 due to hydraulic pressure, it is held between the piston 5 and the stopper surface 10. As is well known, the inside of the automatic transmission is A
Since the clutch plate 11 and the clutch disk 13 are all filled with TF, they are all immersed in ATF.

In this embodiment, the clutch plate 1
1 has a wavy shape, not a normal plain shape.
More specifically, as shown in FIG. 1, the clutch plate 11 is manufactured by punching a press, and at the time of punching, portions other than the protrusions 11a alternate with gentle peaks and valleys at intervals of 60 degrees in the circumferential direction. It is formed as follows. In other words, all parts other than the protruding part 11a are curved so as to be displaced in the plate thickness direction, and this part is used as the elastic part 11b. In FIG. 2, the peaks of the elastic portion 11 b are indicated by Δ and the valleys are indicated by X. Needless to say, if the clutch plate 11 is turned over, the relationship between the peak and the valley is reversed.

The swell amount s of the elastic portion 11b shown in FIG. 3, that is, the height difference between the peak portion and the valley portion is set to less than half of the plate thickness t. When there is no clutch plate 11, the clutch plate 11 and the clutch disc 13 are designed so as not to contact each other.
In FIGS. 1 and 3, s> t because swell of the clutch plate 11 is exaggerated. However, in actuality, s ≦ １ ／.
t. The entire clutch plate 11 including the elastic portion 11b has elasticity, and easily bends when receiving the pressing force of the piston 5 to be flat.

In this embodiment, the clutch plate 11 functions as a first friction plate and the clutch disc 13
Function as a second friction plate. Next, the operation of the wet multi-plate clutch device configured as described above will be described. First, when the ATF is not supplied to the hydraulic chamber 8, the piston 5 is held at the original position on the left side in FIG. The input shaft 1 and the clutch housing 3 are always rotating, and each clutch plate 11 is rotated by receiving the rotational force through the spline groove 12.
, The rotational force is not transmitted to the clutch disk 13, the clutch device is held in the released state, and the clutch hub 2 continues to stop.

Then, the ATF is transferred to the hydraulic chamber 8 through the oil passage 9.
Is supplied, the piston 5 moves to the right in FIG.
The clutch device is switched to the engaged state while holding the clutch disc 1 and the clutch disc 13 therebetween. At this time, the elastic portion 11b of the clutch plate 11 is bent by receiving the pressing force of the piston 5 and becomes flat, so that the elastic portion 11b is brought into close contact with the entire surface of the friction material 13b of the clutch disk 13 to generate a sufficient frictional force, and the input shuff 1 Power is reliably transmitted from the clutch side to the clutch hub 2 side.

On the other hand, when the supply of the ATF to the hydraulic chamber 8 is stopped, the piston 5 is returned to the left original position by the elasticity of the inner seal 6 and the outer seal 7 as described above.
When the pressing force of the piston 5 is released, the elastic portion 11b of each clutch plate 11 returns to its original shape due to its own elasticity, and a peak or a valley portion is applied to the surface of the friction material 13b of the clutch disc 13 on both sides. Contact the clutch disc 13
Is separated from the surface of the friction material 13b while expanding the interval of the friction material 13b. Also, the friction material 13
Since the ATF flows into the gap along with the rotation of the clutch plate 11, the peak or the valley contacting the portion b is quickly separated from the friction material 13 b. That is, not only the pressing force of the piston 5 is released, but also each clutch plate 11 is positively separated from the clutch disk 13 by utilizing the elasticity of the elastic portion 11b. State, and the input shuff 1
Power transmission from the clutch side to the clutch hub 2 is stopped.

As described above, in the wet-type multi-plate clutch device of the present embodiment, the elastic portion 11b is provided only by forming the clutch plate 11 itself in a curved shape. It is possible to prevent the occurrence of troubles due to the complicated structure as in the clutch device described in (1), and to manufacture the clutch device at extremely low cost.

Further, since the clutch plate 11 itself functions as the elastic portion 11b, it is not necessary to secure a space for riveting the leaf spring on the clutch disk unlike the conventional clutch device. Accordingly, it is possible to prevent the area of the clutch plate 11 and the clutch disk 13 from being enlarged, and to sufficiently meet the demand for space saving of the automatic transmission.

In the above-described embodiment, the elastic portion 11b of the clutch plate 11 is continuously formed in a wavy shape in the circumferential direction. However, the present invention is not limited to this. Any other shape may be used as long as it is curved so that the separation between the clutch plate 11 and the clutch disc 13 can be promoted by elasticity when the clutch is released. Accordingly, for example, as shown in FIGS. 4 and 5, the cross sections of the elastic portions 21a and 31a are
31 may be changed in the radial direction (vertical direction in the figure).
To explain these different examples, the clutch plate 2 shown in FIG.
In 1, the cross section of the elastic portion 21a has an arc shape in the radial direction,
In the clutch plate 31 of FIG. 5, the cross section of the elastic portion 31a is inclined in the radial direction, and in each case, the cross section of the clutch plates 21 and 31 is all the same in the circumferential direction.
These elastic portions 21a and 31a bend when the clutch is engaged and become flat, and return to the original shape by elasticity when the clutch is released, thereby promoting separation from the clutch disc 13.

In the above embodiment, the elastic portion 11b is provided on the clutch plate 11 side. However, the present invention is not limited to this. For example, an elastic portion may be provided on the clutch disk 13 side, Further, if the cross section does not change in the circumferential direction as shown in FIGS. 4 and 5, elastic portions may be provided on both the clutch plate 11 and the clutch disk 13. Even in such a configuration, the clutch releasing operation can be positively performed by utilizing the elasticity.

Further, in the above-described embodiment, the clutch device for transmitting the rotation of the input shaft 1 to the clutch hub 2 in the automatic transmission is embodied. However, the present invention is not limited to this. Any other clutch device that performs the engagement / disengagement operation may be used. For example,
The wet multi-plate brake device that regulates the rotation of the planetary carrier in the automatic transmission is simply referred to as a brake device in terms of the function of regulating the rotation, and the actual configuration is the same as the clutch device of the embodiment. Therefore, these brake devices may be embodied. Further, other than the automatic transmission, for example, it may be embodied as a wet multi-plate clutch for adjusting the front-rear torque distribution of a 4WD vehicle.

[0023]

As described above, according to the wet clutch device of the present invention, since the separation of the friction plate is promoted by utilizing the elasticity of the elastic portion, the clutch can be reliably and promptly released. Since the elastic portion is provided only by bending the friction plate itself, the structure of the clutch device is not complicated at all, troubles can be prevented from occurring, and it can be manufactured at extremely low cost. Since the friction plate itself functions as the elastic portion, it is possible to prevent the area of the friction plate from expanding, and to sufficiently meet the demand for space saving.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a released state of a wet multi-plate clutch device according to an embodiment.

FIG. 2 is a front view of a clutch plate.

FIG. 3 is a detailed sectional view showing a relationship between a clutch plate and a clutch disk.

FIG. 4 is a detailed cross-sectional view showing another example of a clutch plate having a circular cross section in a radial direction.

FIG. 5 is a detailed cross-sectional view showing another example of a clutch plate whose cross section is inclined in the radial direction.

[Explanation of symbols]

Reference Signs List 1 input shaft (first member) 2 clutch hub (second member) 4 cylinder (pressing means) 5 piston (pressing means) 11, 21, 31 clutch plate (first friction plate) 11b, 21a, 31a elastic part 13 clutch disk (second friction plate)

Claims (1)

[Claims] A plurality of first friction plates which are arranged in the axial direction and are attached to the first member so as to be axially movable and restricted in rotation, and between the first friction plates. A plurality of second friction plates attached alternately to the second member rotating relative to the first member, the second friction plate being movable in the axial direction and being restricted in rotation, Pressing operation means capable of applying a pressing force in the axial direction to the first friction plate and the second friction plate to perform power transmission between the first member and the second member; A wet clutch device, comprising: at least one of a friction plate and a second friction plate; and an elastic portion curved and formed so as to be displaced in a plate thickness direction.