JPH10281178A - Manufacture of piston for clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple manufacturing method for a piston for a clutch at a reduced cost. SOLUTION: A piston 4 is not integrally manufactured from a first time but divided into cylindrical internal and external members 45 and 47, and each member is manufactured. Even the external member 47 is simply manufactured through throttle processing. In this way, the internal member 45 is fitted in the external member 47 for temporary assembly. As the temporary assembly is rotated, a roll 50 is pressed and to form an O-ring groove 43. Simultaneously, caulking coupling is effected so that the two members are not disassembled. In intercoupling of the internal and external members, other various means, such as press-in or welding, are considered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of manufacturing a piston acting on a friction plate of a clutch used for an automatic transmission of an automobile.

[0002]

2. Description of the Related Art FIG. 1 is a sectional view showing an example of a clutch device, wherein 1 is a shaft, 2 is a clutch housing, 3 is a friction plate, 4 is a piston acting on the friction plate, and 5 is a hydraulic chamber behind the piston. , 6 is a spring for returning the piston, and 7 is a spring receiver (only one of the drive shaft and the driven shaft 1 is shown in the drawing, and the other shaft combined with the friction plate is shown in the drawing. Is omitted.) Reference numeral 8 denotes an O-ring. FIG. 2 shows the piston 4 taken out. The piston 4 includes an operating portion 41 acting on the piston, a rim portion 42 engaged with a shaft or the like, an O-ring groove 43 into which the O-ring 8 is fitted, and the like. The operating portion 41 requires a sufficient plate thickness, but the other portions have a large change in thickness due to structural restrictions and weight reduction. Therefore, the shape is complicated. In addition, airtightness is necessary from the operation of the piston. For this reason, conventionally, forging and cutting are performed from one steel slab, or a single steel sheet is shown in FIG. 2 by making full use of energy and advanced processing technology for large forming processes such as press forming and rotational forming. It was molded into an integrated piston with such a complicated shape.

According to the conventional method of processing an integrated piston, since the shape of the piston is complicated, in the case of processing using a plastic working technique such as forging,
Since a large amount of processing energy is required, there is a drawback that a large-sized processing machine is required, and that a large number of man-hours are required for forming and finishing. In addition, in terms of materials, there is a problem that the entire material must be made of a single material.
As a result, there has been a problem that the processing cost and the material cost are increased.

According to the present invention, in order to solve the above-mentioned problems, a clutch piston is divided into a cylindrical inner member and an outer member, and after forming each member,
An inner member is fitted into an outer member, and the two members are joined to obtain a method of manufacturing a clutch piston.

FIG. 3 shows a first embodiment of the present invention, in which a piston having a complicated shape shown in FIG. 2 is divided into a cylindrical inner member 45 and an outer member 47. 46 is a groove to which a sealing material is added. Since the inner member 45 is not a strength member, a non-ferrous metal or plastic material can be used. Although the outer member 47 also has the rim portion 42 and the like, the steel material can be easily formed by a method such as press drawing. The inner member 45 and the outer member 47 are manufactured as described above, and as shown in FIG. 4, the inner member 45 is fitted into the outer member 47 and assembled, and as shown in FIG. The roll 50 is pressed while rotating the piston 4 assembled to form the roll groove 43, and at the same time, the inner and outer members are integrated into a state that cannot be disassembled. Reference numeral 46 denotes a groove as described above, to which a sealing material is added. FIG.
Shows another embodiment, in which a piston is connected to a cylindrical inner member 45.
And the outer member 47 are formed separately. However, in this example, the O-ring groove 4 is already formed in the outer member 47.
3 are formed simultaneously. As shown in FIG. 7, the inner member 45 is fitted into the outer member 47 to form the piston 4. At this time, the inner member may be connected to the outer member by press fitting, or may be connected to each other by welding after fitting.

According to the method of the present invention, a piston having a complicated shape is divided into a plurality of groups of simple shapes.
General processing means and processing methods can be used, and inexpensive optimal materials that are easily available can be applied to each part.For example, non-ferrous metals and plastics other than steel can be used for inner members that do not require much strength As a result, it was possible to reduce processing costs, material costs, and weight.

[Brief description of the drawings]

FIG. 1 is a sectional view of a clutch to which the present invention is applied;

FIG. 2 is a diagram showing a piston taken out.

FIG. 3 is a diagram showing a state in which a piston is divided.

FIG. 4 is a diagram showing a temporary assembled piston.

FIG. 5 is a diagram showing a crimping assembly example.

FIG. 6 is a view showing another example in which a piston is divided.

FIG. 7 is a diagram showing a state where members are combined.

[Explanation of symbols]

 1 shaft 2 clutch housing 3 friction plate 4 piston 5 hydraulic chamber 6 return spring 7 spring receiver 8 O-ring 41 operating part 42 rim part 43 O-ring groove 45 inner member 46 sealant addition groove 47 outer member

Claims (1)

[Claims] In a method of manufacturing a piston of a clutch having a friction plate, a piston for pressing the plate, a spring for returning the piston, and the like, the piston is divided into a cylindrical inner member and an outer member, A method for manufacturing a clutch piston, comprising: after forming a member, fitting an inner member into an outer member and joining the two members.