JP2001234947A - Manufacturing method for wave disc for friction engagement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wave disc for a friction engagement device to make a wavy curving in the direction across the plate thickness wherein the circumferential direction is put identical to the wave-length direction, whereby it is possible to obtain a uniform wave height over the range from the inside to the peripheral surface. SOLUTION: In the direction across the plate thickness, a work 3' for disc consisting of a ring-shaped flat plate is pressurized between a stationary die 100 of such a structure that a plurality of pressing parts 101 mating with crests or bottoms of the wave shape of a wave disc are installed protrusively in radial arrangement and a movable die 200 of such a structure that a plurality of pressing parts 201 mating with the other of the crests and bottoms are installed protrusively in the radial arrangement. The two sorts of pressing parts 101 and 201 are formed so that the protrusion height of each pressing part in the direction in which the stationary die and movable die are mating with each other is greater at the inside surface of the work 3' than at its periphery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a wave disk for a friction engagement device used as a transmission clutch or a brake of an automatic transmission for a vehicle.

[0002]

2. Description of the Related Art A friction engagement device includes an external gear disk spline-engaged with an outer member and an internal gear disk spline-engaged with an inner member. It is configured such that torque is transmitted between the outer member and the inner member by being brought into pressure contact and frictionally engaged.

Conventionally, in such a friction engagement device,
It is known that one of the external tooth disk and the internal tooth disk is constituted by a wave disk which is curved in a thickness direction with a circumferential direction being a wavelength direction (Japanese Patent Laid-Open No. 9-25).
No. 7058).

[0004] When the wave disk as described above is used,
The wave disk is pressed against another disk while the wave-shaped peaks and valleys are elastically deformed in the early stage of engagement, and the sudden rise of torque in the early stage of engagement is prevented by the buffering action due to the elastic deformation of the peaks and valleys Thus, the engagement shock is reduced. Further, at the time of disengagement, the wave disk is quickly separated from other disks due to the elastic restoring force of the peaks and valleys, and dragging is suppressed.

Conventionally, as a method for manufacturing such a wave disk, a fixed type in which a plurality of pressing portions corresponding to one of the peaks and valleys of the waveform of the wave disk are projected radially, and a method corresponding to the other of the peaks and valleys of the waveform. Using a pressing device having a movable die having a plurality of pressing portions protruding radially, a disk material made of an annular flat plate is pressed between a fixed die and a movable die in the thickness direction to press-mold a wave disk. Things are known.

[0006]

By the way, when the inner peripheral side and the outer peripheral side of the disk material are compared, the rigidity with respect to the elongation at the time of press molding is higher on the inner peripheral side where the peripheral length is shorter than on the outer peripheral side. Even if each pressing portion has the same cross-sectional shape over the entire length in the radial direction of the disc material and is press-formed so as not to cause a stroke difference between the inner peripheral side and the outer peripheral side of the disc raw material, The amount of springback on the circumferential side increases, so that the wave height of the waveform shape of the wave disk becomes smaller on the inner circumferential side and becomes larger on the outer circumferential side. As a result, when used, the wave disk comes into contact with other disks more on the outer peripheral side, and there is a possibility that abrasion may be faster on the outer peripheral side than on the inner peripheral side.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a method capable of manufacturing a wave disk having a uniform wave height from the inner peripheral side to the outer peripheral side.

[0008]

Means for Solving the Problems In order to solve the above problems,
The present invention relates to a method of manufacturing a wave disk used as a disk for a friction engagement device, which is curved in a thickness direction with a circumferential direction being a wavelength direction, and corresponds to one of peaks and valleys of a wave shape of the wave disk. A disk material made of an annular flat plate using a pressing device having a fixed type in which a plurality of pressing portions to be radially protruded and a movable type in which a plurality of pressing portions corresponding to the other of the wavy peaks and valleys are radially protruded. Pressing the wave disc between the fixed mold and the movable mold in the thickness direction, and press-molding the wave disc, the forming load applied to the disc material by each pressing part is more on the inner peripheral side than on the outer peripheral side of the disc material. The press forming was performed such that each pressing portion had the same cross-sectional shape over the entire length in the radial direction of the disk material. Compared to the case, so that increased. In order to increase the difference between the molding load on the inner circumference and the outer circumference of the disc material,
What is necessary is just to form so that the protruding height of each pressing part in the facing direction of the fixed type and the movable type may be larger on the inner peripheral side than on the outer peripheral side of the disk material.

According to the present invention, the amount of elongation on the inner peripheral side of the disk material at the time of press molding is larger than when each pressing portion has the same cross-sectional shape over the entire length. Here, the amount of springback after press molding is larger on the inner peripheral side than on the outer peripheral side, but by extending the inner peripheral side greatly during press molding, the wave height on the inner peripheral side is increased by springback. The difference from the wave height on the outer circumference side is reduced, and a wave disk having a uniform wave height from the inner circumference side to the outer circumference side can be obtained.

[0010]

FIG. 1 shows a hydraulic clutch for an automatic transmission as a friction engagement device. This hydraulic clutch includes a clutch drum 1 as an outer member connected to a power transmission shaft S, and a clutch hub 2 as an inner member integrally formed with a speed change gear G supported on the power transmission shaft S. In the clutch drum 1, a plurality of externally toothed discs 3 spline-engaged with spline portions 1a formed on the clutch drum 1 by outer teeth 3a, and inner teeth formed on spline portions 2a formed on the clutch hub 2. The plurality of internal gear disks 4 that engage with the spline at 4a are alternately arranged in the axial direction.

When the opening direction of the clutch drum 1 is set to the outside in the axial direction, the outermost disk 3 in the axially outermost position is prevented from falling out of the clutch drum 1 by the circlip 5.
A piston 6 is provided in the clutch drum 1 so as to face the axially innermost external tooth disk 3. A power transmission shaft S is provided in a hydraulic chamber 7 defined between the end wall of the clutch drum 1 and the piston 6. When the pressurized oil is supplied through the oil passage Sa formed in the above, the piston 6 moves outward in the axial direction against the return spring 8, and the external tooth disk 3 and the internal tooth disk 4 are attached to the internal tooth disk 4. The clutch drum 1 and the clutch hub 2 are pressed in the axial direction via the friction material 9 and frictionally engaged with each other.
Is transmitted. Note that lubricating oil is supplied to the disposition portions of the disks 3 and 4 from a lubricating oil passage Sb formed in the power transmission shaft S.

As shown in FIGS. 2 and 3, the external tooth disk 3 is formed of a wave disk that is curved in a wave form in the thickness direction with the circumferential direction being the wavelength direction. In the illustrated example, the number of waves formed on the external tooth disk 3 is three, but the number is arbitrary.

When manufacturing the external tooth disk 3, FIG.
(A) As shown in (B), using a pressing device having a fixed lower die 100 and a movable upper die 200, a disk blank 3 'made of an annular flat plate having teeth 3a on the outer periphery.
Is pressed between the lower mold 100 and the upper mold 200 in the thickness direction. On the upper surface of the lower die 100, a plurality of pressing portions 101 corresponding to the corrugated peaks 3b of the external tooth disk 3 are radially projected, and on the lower surface of the upper die 200, the pressing portions 101 are provided.
A plurality of pressing portions 201 corresponding to the corrugated valleys 3c of the external tooth disk 3 are radially protrudingly provided between the arrangement pitches. Thus, the disk material 3 'is
When the upper die 200 is set down and then the upper die 200 is lowered, the disk material 3 ′ is bent downward at the contact portion of the pressing portion 201 on the upper die 200 side and the pressing portion 101 on the lower die 100 side.
Is pressed upward at the abutting point, and the corrugated external tooth disk 3 is press-formed.

Here, the vertical end portions of the pressing portions 101 and 201 are formed in a half conical shape whose diameter increases toward the inner peripheral side of the disk material 3 ′. The protruding height of each pressing portion 101, 201 in the direction facing the mold 200, that is, in the vertical direction, is greater on the inner peripheral side than on the outer peripheral side of the disk material 3 '.
02 has a larger contact width in the circumferential direction with respect to the disk material 3 ′ on the inner peripheral side than on the outer peripheral side of the disk raw material 3 ′. Therefore, the disc material 3 ′ is formed by the pressing portions 101 and 201.
Is larger on the inner peripheral side than on the outer peripheral side of the disk material 3 ′, and the difference between the molding loads on the inner and outer peripheral sides of the disk material 3 ′ is the difference between the pressing parts 101 and 201.
Is larger than that in the case of press-molding with the same cross-sectional shape over the entire length in the radial direction of the disk material 3 ′. As a result, the disc material 3 '
Of the disk material 3 is larger than that using the pressing portion having the same cross-sectional shape over the entire length, and the wave height on the inner circumferential side of the disk material 3 is larger than the wave height on the outer circumferential side. Then, when a larger springback occurs on the inner peripheral side of the disc than on the outer peripheral side after the press molding, the difference between the inner peripheral side wave height and the outer peripheral side wave height decreases, and the wave height increases from the inner peripheral side to the outer peripheral side. Can be obtained.

In the above embodiment, each pressing portion 101,
201 is formed so that both the protruding height and the width are larger on the inner peripheral side than on the outer peripheral side of the disc material, but one of the protruding height and the width is on the inner peripheral side than the outer peripheral side of the disc material. May be formed so as to be large.

The case where the external teeth disk 3 is constituted by a wave disk has been described above. However, when the internal teeth disk 4 is constituted by a wave disk, the internal teeth disk 4 can be manufactured in the same manner as described above. Further, a wave disc of another frictional engagement device such as a hydraulic brake other than the hydraulic clutch can be manufactured in the same manner as described above.

[0017]

As is apparent from the above description, according to the present invention, a wave disk having a uniform wave height from the inner peripheral side to the outer peripheral side can be easily obtained, and the abrasion is smaller than that of the inner peripheral side. However, it is possible to prevent the outer periphery from becoming faster.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a hydraulic clutch having a wave disk manufactured by the method of the present invention.

FIG. 2 is a perspective view of a wave disk.

FIG. 3 is an expanded sectional view of a wave disk.

4A is a perspective view of a press apparatus for manufacturing a wave disk in an open state, and FIG. 4B is a perspective view taken along line IVB-IVB of FIG. 4A.
Sectional view at the time of press molding cut by a line

[Explanation of symbols]

 3 external tooth disk (wave disk) 3 'disk material 3b crest 3c trough 100 lower die (fixed type) 200 upper die (movable type) 101,201 pressing part

Claims (2)

[Claims] 1. A method for producing a wave disk, which is used as a disk for a friction engagement device and is curved in a thickness direction with a circumferential direction being a wavelength direction, comprising: A disk made of an annular flat plate using a pressing device having a fixed type in which a plurality of corresponding pressing portions are radially protruded and a movable type in which a plurality of pressing portions corresponding to the other of the wave-shaped peaks and troughs are radially protruded. Pressing the material in the thickness direction between the fixed mold and the movable mold to press-mold the wave disc. The forming load applied to the disc material by each pressing part is closer to the inner circumference than to the outer circumference of the disc material. And become large, and
The difference between the forming loads on the inner peripheral side and the outer peripheral side of the disk material is set to be larger than that in the case where each pressing portion is press-formed as having the same cross-sectional shape over the entire length in the radial direction of the disk material, A method of manufacturing a wave disk for a friction engagement device, characterized by comprising: 2. The method according to claim 1, wherein each of the pressing portions is formed such that a protruding height of each of the pressing portions in an opposing direction between the fixed mold and the movable mold is larger on the inner peripheral side than on the outer peripheral side of the disk material. The method for producing a wave disk for a friction engagement device according to claim 1.