JP3128387B2 - Wet multi-plate friction engagement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet multi-plate friction engagement device used for an automatic transmission for an automobile or a transmission for an industrial or construction machine. Such a wet multi-plate friction engagement device is widely used as a wet multi-plate clutch or a wet multi-plate friction brake in a planetary gear mechanism.

[0002]

2. Description of the Related Art A wet multi-plate friction engagement device is a device mainly for transmitting torque, and is used in oil. Therefore, it must be excellent in high torque transmission capacity, and must be able to withstand high temperatures. In addition, problems such as shock and abnormal noise upon completion of engagement must be considered.

[0003]

In order to obtain a high torque transmission capacity, it is sufficient to use a friction material having a large static friction coefficient. However, a friction material having a large static friction coefficient has no excellent heat resistance, and has a small dynamic friction coefficient.

On the other hand, in order to prevent shock and abnormal noise upon completion of engagement, the coefficient of kinetic friction is large (in the specification, “a large coefficient of kinetic friction” means (dynamic friction coefficient /
(It means that the ratio of the coefficient of static friction is large.) A friction material may be used. Such a friction material generally has excellent heat resistance. However, a friction material having a large dynamic friction coefficient and excellent heat resistance has a small static friction coefficient and a small torque transmission capacity.

At present, it has a high torque transmission capacity,
Moreover, a friction material having a high dynamic friction coefficient and excellent heat resistance is difficult to obtain in the market. Therefore, a wet multi-plate friction engagement device capable of meeting such demands, that is, a wet type friction device having all of the above characteristics, A multiple disc friction engagement device cannot be obtained.

An object of the present invention is to provide a wet multi-plate friction engagement device having all of the above characteristics.

[0007]

According to the present invention, there is provided a wet multi-plate friction engagement device in which inner disks and outer disks are alternately arranged, wherein the inner disk and the outer disk have a friction material only on one side. The friction material is a first friction material having a relatively large static friction coefficient, or a second friction material having a relatively large dynamic friction coefficient and heat resistance.
This problem has been solved by a wet multi-plate friction engagement device in which the thickness of the core plate of the disk facing the friction material is relatively large, and the thickness of the core plate of the disk facing the second friction material is relatively thin.

[0008]

The inner disk and the outer disk both have a friction material on the same surface. No friction material is stuck on the back. Thus, the friction material engages the core plate of the opposing disk.

The friction material includes a first friction material and a second friction material. The first friction material has a relatively large coefficient of static friction. The thickness of the core plate facing the first friction material is relatively large. The heat generated during the engagement is easily diffused through the core plate, and the heat resistance of the first friction material is supplemented.

[0010] The core plate facing the second friction material includes:
Its thickness is relatively thin. Since the second friction material has relatively excellent heat resistance, it is not always necessary to consider heat diffusion. Rather, it is thinner to reduce the overall length of the wet multi-plate frictional engagement device as a whole.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially enlarged cross-sectional view of the automatic transmission. The wet multi-plate friction engagement device 10 includes a hydraulic operating mechanism (not shown) such as a piston, an inner disk 20 spline-fitted to the outer race 14 of the wayway clutch 12, and an outer disk spline-fitted to the housing 16. 30.

FIG. 2 shows the inner disk 20 and the outer disk 30. Friction members 24 and 34 are attached to one surface of the core plates 22 and 32 of the inner disk 20 and the outer disk 30, respectively. No friction material is attached to the other surface. The thickness of the core plate 22 of the inner disk 20 is relatively thin, and the thickness of the core plate 32 of the outer disk 30 is relatively thick.

The friction material 24 of the inner disk 20 is a friction material having a relatively large static friction coefficient. This friction material 24
It engages with the core plate 32 of the outer disk 30. The friction material 34 of the outer disk 30 is a friction material having a relatively large dynamic friction coefficient and excellent heat resistance. This friction material 34
Engage with the core plate 22 of the inner disk 20.

Therefore, since the friction material 24 having a relatively large coefficient of static friction is engaged with the relatively thick core plate 32, the heat generated at the time of friction engagement is reduced by the thick core plate 3.
2 is diffused. Since the friction material 34 having a relatively large dynamic friction coefficient has excellent heat resistance, it is not necessary to make the opposing core plate 22 thick. Rather, a thinner one is preferred to reduce the overall length of the wet multi-plate friction engagement device 10.

As described above, although the heat resistance is somewhat inferior, a friction plate capable of securing a high torque transmission capacity, that is, a core plate facing a friction material having a relatively large static friction coefficient is made relatively thick. Although the torque transmission capacity is somewhat inferior, the wet multi-plate friction engagement device having these characteristics is obtained by relatively thinning the core plate facing the friction material having a relatively large dynamic friction coefficient and excellent heat resistance. be able to.

[0016]

As described above, the present invention makes use of commercially available friction materials, the second friction material compensates for the disadvantages of the first friction material, and the disadvantages of the second friction material. By configuring the first friction material to compensate for the points, it is possible to obtain a wet multi-plate friction engagement device having all of the characteristics of high torque transmission capacity, heat resistance, and high dynamic friction coefficient.

[Brief description of the drawings]

FIG. 1 is a partially enlarged sectional view of a wet multi-plate friction engagement device according to the present invention.

FIG. 2 is an enlarged sectional view of an outer disk and an inner disk.

[Explanation of symbols]

REFERENCE SIGNS LIST 10 wet multi-plate friction engagement device 20 inner disk 22 core plate 24 friction material (friction material having relatively large static friction coefficient) 30 outer disk 32 core plate 34 friction material (relatively large friction coefficient and heat-resistant friction material) )

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16D 11/00-23/14 F16D 55/40 F16D 69/00

Claims (1)

(57) [Claims] 1. A wet multi-plate friction engagement device in which an inner disk and an outer disk are alternately arranged, wherein the inner disk and the outer disk have a friction material only on one side, and the friction material is a comparative material. A first friction material having a large static coefficient of static friction, or a second friction material having a relatively large dynamic friction coefficient and heat resistance, wherein the core plate of the disk facing the first friction material has a relatively large thickness, The wet multi-plate friction engagement device, wherein a thickness of a core plate of the disk facing the second friction material is relatively small.