JPH06179029A - Manufacture of piston for clutch - Google Patents

Abstract

PURPOSE:To improve the manufacturing efficiency of a piston for a clutch. CONSTITUTION:In a manufacture of a piston 9 for a clutch, a process forming a boss part 18 by burring a circumferential part of a prepared hole 24 in a central part of a circular disk like blank 25, a process forming an outer circumferential thick wall part 26 by compressing the circumferential part to an inside of radius direction and increasing a thick wall while rotating the blank 25, together forming a piston body 16, and a process forming a seal member attaching annular groove 21 together forming a rim part 17 by pressing an annular projecting shaped part of the outer circumferential surface of forming roller are orderly executed. In such a manner, the manufacturing efficiency of the piston 9 can be improved by adopting a cold deformation processing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a friction type multi-disc clutch,
Clutch pistons used in clutches of automatic transmissions, in particular, rims formed on the outer peripheral edge of an annular disc-shaped piston body that are thicker than the piston body and slide on the inner peripheral surface of the outer cylinder of the clutch housing. A boss that slides on the outer peripheral surface of the inner cylindrical portion of the clutch housing, which is concentric with the outer cylindrical portion of the clutch housing, and an annular groove for mounting the seal member on the outer peripheral surface of the rim. And a method for manufacturing a clutch piston.

[0002]

2. Description of the Related Art Conventionally, in the manufacture of this type of piston, a method has been adopted in which a piston material is manufactured under the application of a casting method or a hot forging method, and then the piston material is machined. .

[0003]

However, in any of the above-mentioned conventional methods, the piston material must be manufactured at a high temperature, so that the manufacturing workability is poor and the number of manufacturing steps is large, so High manufacturing cost,
There is such a problem.

In view of the above, the present invention has made it possible to solve the above problems by manufacturing the piston by cold plastic working or by combining cold plastic working and cutting. It is an object of the present invention to provide the above manufacturing method.

[0005]

According to the present invention, a rim portion which is formed thicker than the piston body and slides on the inner peripheral surface of the outer cylinder portion of the clutch housing is connected to the outer peripheral edge of the annular disc-shaped piston body. And a boss portion that slides on the outer peripheral surface of the inner cylindrical portion of the clutch housing that is concentric with the outer cylindrical portion of the clutch housing, the outer peripheral surface of the rim portion having a ring groove for mounting a seal member. In manufacturing the clutch piston provided with, a step of forming the boss portion by performing burring processing on the prepared hole peripheral portion of the disk-shaped blank central portion, and a radial direction of the outer peripheral portion while rotating the blank. A step of forming the outer peripheral thick part by increasing the wall thickness by compressing inward and forming the piston body, and rotating the blank on the outer peripheral thick part outer peripheral surface of the forming roller outer peripheral surface. Ring A step of forming the rim portion with to press the mold portion for molding the sealing member fitting annular groove, characterized by using.

Further, according to the present invention, a rim portion which is formed thicker than the piston body and slides on the inner peripheral surface of the outer cylinder portion of the clutch housing is continuously provided on the outer peripheral edge of the annular disc-shaped piston body, and For a clutch in which a boss portion that slides on an outer peripheral surface of an inner cylindrical portion concentric with the outer cylindrical portion of the clutch housing is continuously provided on an inner peripheral edge of the piston body, and an annular groove for mounting a seal member is provided on an outer peripheral surface of the rim portion. In manufacturing the piston, a step of forming a boss portion by performing a burring process on the peripheral hole of the disk-shaped blank central portion and a burring process on the outer peripheral portion of the blank in the same direction as the boss portion. A step of forming an annular convex edge that bends to, and one surface of the blank existing on the side opposite to the bending direction of the annular convex edge, the region inside the annular convex edge is extruded in the bending direction, and the one surface Perimeter A step of forming an outer peripheral thick part formed of both annular convex edges by forming an annular convex edge on the outer peripheral thick part outer peripheral surface while rotating the blank, and an annular convex part of the outer peripheral surface of the forming roller. A step of pressing to form the sealing member mounting annular groove and the rim portion and the piston body.

Further, according to the present invention, a rim portion which is formed thicker than the piston body and slides on the inner peripheral surface of the outer cylinder portion of the clutch housing is continuously provided on the outer peripheral edge of the annular disk-shaped piston body, and For a clutch in which a boss portion that slides on an outer peripheral surface of an inner cylindrical portion concentric with the outer cylindrical portion of the clutch housing is continuously provided on an inner peripheral edge of the piston body, and an annular groove for mounting a seal member is provided on an outer peripheral surface of the rim portion. When manufacturing a piston,
A step of forming the boss portion by performing burring processing on the peripheral hole peripheral portion of the disk-shaped blank center portion, and an annular convex edge bent in the same direction as the boss portion by performing burring processing on the outer peripheral portion of the blank. In the step of molding, on the one surface of the blank present on the side opposite to the bending direction of the annular convex edge,
A region inside the annular convex edge is extruded in the bending direction to form an annular convex edge on the outer peripheral portion of the one surface, thereby forming the rim portion composed of both annular convex edges and forming the piston body. And a step of cutting the outer peripheral surface of the rim portion to form the seal member mounting annular groove.

[0008]

As described above, when the piston is manufactured by the cold plastic working or the combination of the cold plastic working and the cutting, the workability of manufacturing the piston becomes good.

[0009]

1 shows a clutch 1 for an automatic transmission having a piston obtained according to the present invention. The tubular clutch housing 2 has an annular end wall portion 5 continuously provided between one ends of an outer tubular portion 3 and an inner tubular portion 4 which are concentrically arranged. A hollow drive shaft 6 is continuously provided coaxially with the tubular portion 4. The drive shaft 6 is supported by the casing 8 via bearings 7. A disk-shaped piston 9 is slidably fitted between the inner peripheral surface of the outer cylindrical portion 3 and the outer peripheral surface of the inner cylindrical portion 4, and a hydraulic chamber 10 is defined between the piston 9 and the end wall portion 5. To be done. A return spring 11 is connected to the piston 9 and the return spring 11
Urges the piston 9 in the clutch disengagement direction. Outer tube part 3
A plurality of drive clutch plates 14 and driven clutch plates 15 are alternately arranged between the inner peripheral surface and the outer peripheral surface of the tubular portion 13 of the driven member 12. Each drive clutch plate 14 is spline-connected to the inner peripheral surface of the outer tubular portion 3, and each driven clutch plate 15 is spline-connected to the outer peripheral surface of the tubular portion 13.

In the above structure, when hydraulic pressure is supplied to the hydraulic chamber 10, the hydraulic pressure causes the piston 9 to move forward, the driving clutch plate 14 is pressed against the driven clutch plate 15 and the clutch 1 is connected, whereby the driving shaft 6 is driven. Driven member 12
Power is transmitted to. On the other hand, when the supply of the hydraulic pressure to the hydraulic chamber 10 is released, the piston 9 is retracted by the elastic force of the return spring 11 and the clutch 1 is disengaged, whereby the power transmission is released.

The piston 9 is an annular disc-shaped piston body 1.
6 and a rim portion 1 that is continuously provided on the outer peripheral edge of the piston body 16 and slides on the inner peripheral surface of the outer tubular portion 3 of the clutch housing 2.
7 and a boss portion 18 that is connected to the inner peripheral edge of the piston body 16 and slides on the outer peripheral surface of the inner tubular portion 4 of the clutch housing 2. The rim portion 17 has an annular convex portion 19 that abuts the annular end wall portion 5 of the clutch housing 2 to restrict the retreat limit of the piston 9 and forms the hydraulic chamber 10 at the outer peripheral edge thereof. The rim portion 17 is formed thicker than the piston body 16, an annular groove 21 for mounting the seal member 20 is provided on the outer peripheral surface of the rim portion 17, and a seal member 22 is mounted on the inner peripheral surface of the boss portion 18. An annular groove 23 is provided.

Next, a method of manufacturing the piston 9 will be described.

In the first embodiment, as shown in FIGS. 2 (a) to 2 (d), in the step (a), a disc-shaped blank 25 having a prepared hole 24 in the central portion is manufactured, and in the step (b). So blank 2
5, the boss portion 18 is formed around the lower hole 24, the outer peripheral thick portion 26 is formed on the blank 25 and the piston body 16 is formed in the step (c), and the seal member is mounted in the step (d). A process of molding the annular groove 21 and the rim portion 17 is adopted.

FIG. 3 shows a device D for holding and rotating a blank 25 having a boss portion 18 when molding the rim portion 17, the piston body 16 and the annular groove 21. The device D includes a rotation drive unit 27 and a rotation pressing unit 28.
And consists of. The rotation drive unit 27 includes the rotation shaft 29 and the clamp 3
And a first half 30 ₁ 0, the first half 30 ₁ is fitted into a mounting hole 32 for opening the minor portion 31 projecting from its rear surface to the tip surface of the rotary shaft 29 It is connected to the rotating shaft 29.
The rotated pressing portion 28 is coaxial with the rotation shaft 29 and is the first
The pressing shaft 33 that can move back and forth with respect to the half body 30 ₁ and the first half body 3
0 ₁ and the second half body 30 ₂ of the sandwiching tool 30 facing each other,
The second half body 30 ₂ is connected to the pressing shaft 33 by rotatably fitting a shaft portion 34 projecting on the back surface thereof into a mounting hole 35 opening in the tip surface of the pressing shaft 33. Further, an angular contact ball bearing 37 is provided in the bearing housing 36 at the tip of the pressing shaft 33, and the inner race 3 of the ball bearing 37 is provided.
The end surface of 7a is brought into contact with the back surface of the second half body 30 ₂ , and
The shaft portion 34 of the half body 30 ₂ is supported by the ball bearing 37.
As a result, the thrust load and radial load acting on the second half body 30 ₂ are supported by the ball bearing 37.

First half 30₁18 in the center of the front of the
A recessed portion 38 for fitting is formed. Also the first and second half
Body 30₁, 30₂Annular cutout 39 on the outer periphery of the front face of₁，
39 ₂Are formed respectively, and the cutout portions 39 are formed.₁, 3
9₂Is a mold for molding the thick outer peripheral portion 26 and the rim portion 17.
Used as a bitty.

In FIG. 4A, a first tool 40 ₁ for molding the outer peripheral thick portion 26 has a tool body 42 having a forked portion 41 at its tip, a support shaft 43 at the forked portion 41, and its support. It comprises a forming roller 45 supported via a bearing 44 mounted on the shaft 43. The forming roller 45 has an annular concave portion 46 on the outer peripheral surface.

In FIG. 5A, the second tool 40 ₂ for forming the rim portion 17 and the annular groove 21 has a tool body 48 having a forked portion 47 at its tip, and a support shaft 49 and a support shaft 49 at the forked portion 47. The forming roller 51 is supported via a bearing 50 mounted on the support shaft 49. The forming roller 51 has an annular convex portion 52 on the outer peripheral surface.

In manufacturing the piston 9, as shown in FIG.
In the step, the blank 25 is manufactured by punching the material plate, and in the step of FIG. 2B, the boss portion 18 is formed by performing burring around the lower hole 24 of the blank 25.

In the step of FIG. 2C, as shown in FIGS. 3 and 4A, the boss portion 18 of the blank 25 is attached to the first half body 30.
Fitted into _a recess 38, first, second half 30 _1, 30
_The blank 25 is clamped by 2. In this case, the outer peripheral portion of the blank 25 projects by a predetermined length from the outer peripheral surfaces of the first and second halves 30 ₁ and 30 ₂ . Next, the blank 25 is rotated and, as shown in FIG.
₁ is brought close to the blank 25, and the outer peripheral portion of the blank 25 is compressed inward in the radial direction by the concave portion 46 of the forming roller 45. As a result, as shown in FIG. 4 (b), the outer peripheral portion of the blank 25 is plastically deformed and both cutout portions 39 ₁ , 39 ₂ are removed.
Since the cavity 53 formed by the above is filled, the outer peripheral thick portion 26 is molded, and at the same time, the piston body 16 is molded. In this case, the concave mold portion 46 of the molding roller 45 is inserted into the cavity 53 to secure a space 54 for escaping the material when molding the annular groove 21, which will be described later.

In the step of FIG. 2D, the first tool 40 ₁ is retracted from the blank 25, and the second tool 40 ₂ is brought close to the rotating blank 25 as shown in FIG. 5A. The outer peripheral thick portion 26 of the blank 25 is pressed by the convex portion 52 of the forming roller 51. As a result, as shown in FIG. 5B, the outer peripheral thick portion 26 is plastically deformed to form the annular groove 21 and the rim portion 17. In this case, the outer peripheral surface of the rim portion 17 is finished with high accuracy by matching both outer peripheral edges of the convex portion 52 with the opening edge of the cavity 53.

Thereafter, as shown in FIG. 1, the piston 9 is subjected to a predetermined machining process such that the outer peripheral surface of the boss portion 18 is tapered or the annular groove 23 is formed on the inner peripheral surface of the boss portion 18. Is given.

FIG. 6 shows a second embodiment. In this embodiment, in manufacturing the clutch piston 9, in the step (a), a blank is punched into a circle having a pilot hole 24 in the center. A plate-shaped blank 25 is manufactured, and in the step (b), burring is applied to the peripheral portion of the pilot hole 24 of the blank 25 to form the boss portion 18, and in the step (c), burring is applied to the outer peripheral portion of the blank 25. The annular convex edge 55 is formed by bending the same in the same direction as the boss portion 18, and in the step (d), the annular convex edge 5 is formed.
One surface 5 of the blank 25 existing on the side opposite to the bending direction of No. 5
6, the region 57 inside the annular convex edge 55 is extruded in the bending direction and the annular convex edge 58 is press-molded on the outer peripheral portion of the one surface 56, whereby both annular convex edges 55,
The outer peripheral thick portion 59 composed of 58 is molded, and in the step (e),
The blank 25 is clamped in the device D in the same manner as in the step of FIG. 2D in the first embodiment, and while the blank 25 is rotated, the outer peripheral thick-walled portion 59 has an outer peripheral surface and the outer peripheral surface of the forming roller 51 of the second tool 40 ₂ . The annular convex portion 52 is pressed to form the seal member mounting annular groove 21, and the rim portion 17 and the piston body 16 are formed.

FIG. 7 shows a third embodiment. In manufacturing the clutch piston 9 in this embodiment, first, the steps (a) to (c) described in the second embodiment are adopted. That is,
As shown in FIG. 6, in the step (a), the blank blank 25 is punched to have a prepared hole 24 at the center thereof.
Is manufactured, and in the step (b), burring is applied to the peripheral portion of the pilot hole 24 of the blank 25 to form the boss portion 18,
In step (c), the outer peripheral portion of the blank 25 is subjected to burring to form an annular convex edge 55 that is bent in the same direction as the boss portion 18. Then, as shown in FIG. 7, in the same manner as in the second embodiment, in the step (d), the one surface 56 of the blank 25 existing on the side opposite to the bending direction of the annular convex edge 55 is located inside the annular convex edge 55. The region 57 is extruded in the bending direction and an annular convex edge 58 is press-molded on the outer peripheral portion of the one surface 56 to form the rim portion 17 composed of both annular convex edges 55 and 58, and the piston The main body 16 is molded, and in step (e), the outer peripheral surface of the rim portion 17 is cut to form the annular groove 21 for mounting the seal member.

The order of the molding steps is not limited to that of the first and second embodiments, such as the molding of the boss portion 18 in the final step.

[0025]

According to the present invention, a piston is manufactured by cold plastic working or a combination of cold plastic working and cutting, so that the manufacturing efficiency of the piston is improved and the manufacturing cost thereof is reduced. be able to.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a clutch for an automatic transmission.

FIG. 2 is a process explanatory view of the first embodiment.

FIG. 3 is a sectional view of an essential part of a device that clamps and rotates a blank.

FIG. 4 is an explanatory diagram of a process of molding the thick outer peripheral portion and the piston body.

FIG. 5 is an explanatory diagram of a process of forming an annular groove and a rim portion.

FIG. 6 is a process explanatory diagram of the second embodiment.

FIG. 7 is an explanatory view of the main process steps of the third embodiment.

[Explanation of symbols]

 2 clutch housing 3 outer cylinder part 4 inner cylinder part 9 piston 16 piston body 17 rim part 18 boss part 21 annular groove 24 pilot hole 25 blank 26, 59 outer peripheral thick part 51 molding roller 52 convex part 55, 58 annular convex edge 56 one side

Claims (3)

[Claims] 1. An annular disk-shaped piston body (16) having an outer peripheral edge formed to be thicker than the piston body (16) and sliding on an inner peripheral surface of an outer cylinder portion (3) of a clutch housing (2). Rim portion (17) is continuously provided, and the outer peripheral surface of the inner cylindrical portion (4) concentric with the outer cylindrical portion (3) of the clutch housing (2) slides on the inner peripheral edge of the piston body (16). In order to manufacture a piston for a clutch in which a boss portion (18) is continuously provided and an annular groove (21) for mounting a seal member is provided on an outer peripheral surface of the rim portion (17), a central portion of a disc-shaped blank (25) is manufactured. Burring the peripheral portion of the pilot hole (24) to form the boss portion (18), and the blank (2).
5) While rotating 5), the outer peripheral part is radially inwardly compressed to increase the wall thickness, thereby forming the outer peripheral thick part (26) and forming the piston body (16), and the blank. While rotating (25), the annular convex portion (52) on the outer peripheral surface of the forming roller (51) is pressed against the outer peripheral thick portion (26) to form the seal member mounting annular groove (21). And a step of molding the rim portion (17), and a method for manufacturing a clutch piston. 2. An annular disk-shaped piston body (16) having an outer peripheral edge formed to be thicker than the piston body (16) and sliding on an inner peripheral surface of an outer cylinder portion (3) of a clutch housing (2). Rim portion (17) is continuously provided, and the outer peripheral surface of the inner cylindrical portion (4) concentric with the outer cylindrical portion (3) of the clutch housing (2) slides on the inner peripheral edge of the piston body (16). In order to manufacture a piston for a clutch in which a boss portion (18) is continuously provided and an annular groove (21) for mounting a seal member is provided on an outer peripheral surface of the rim portion (17), a central portion of a disc-shaped blank (25) is manufactured. Burring the peripheral portion of the pilot hole (24) to form the boss portion (18), and the blank (2).
The outer peripheral portion of 5) is subjected to burring and the boss portion (1
8) a step of forming an annular convex edge (55) that bends in the same direction as that of the annular convex edge (55), and the annular shape on one surface (56) of the blank (25) present on the side opposite to the bending direction of the annular convex edge (55). A region (57) inside the convex edge (55) is extruded in the bending direction to form an annular convex edge (58) on the outer peripheral portion of the one surface (56), thereby forming both annular convex edges (55, 5).
8) a step of forming an outer peripheral thick part (59), and an annular convex portion of the outer peripheral surface of the forming roller (51) on the outer peripheral thick part (59) outer surface while rotating the blank (25). A step of pressing (52) to form the seal member mounting annular groove (21) and forming the rim portion (17) and the piston body (16). Manufacturing method. 3. An annular disc-shaped piston body (16) having an outer peripheral edge formed to be thicker than the piston body (16) and sliding on an inner peripheral surface of an outer cylinder portion (3) of a clutch housing (2). Rim portion (17) is continuously provided, and the outer peripheral surface of the inner cylindrical portion (4) concentric with the outer cylindrical portion (3) of the clutch housing (2) slides on the inner peripheral edge of the piston body (16). In order to manufacture a piston for a clutch in which a boss portion (18) is continuously provided and an annular groove (21) for mounting a seal member is provided on an outer peripheral surface of the rim portion (17), a central portion of a disc-shaped blank (25) is manufactured. Burring the peripheral portion of the pilot hole (24) to form the boss portion (18), and the blank (2).
The outer peripheral portion of 5) is subjected to burring and the boss portion (1
8) a step of forming an annular convex edge (55) that bends in the same direction as that of the annular convex edge (55), and the annular shape on one surface (56) of the blank (25) present on the side opposite to the bending direction of the annular convex edge (55). A region (57) inside the convex edge (55) is extruded in the bending direction to form an annular convex edge (58) on the outer peripheral portion of the one surface (56), thereby forming both annular convex edges (55, 5).
8) forming the rim part (17) and forming the piston body (16), and cutting the outer peripheral surface of the rim part (17) to attach the seal member annular groove (21). And a step of forming a step for forming a clutch piston.