JPS61175328A - Piston made of metal plate for transmission - Google Patents

Abstract

PURPOSE:To raise the mechanical reliability, by forming a ring groove which opens toward the center of a through hole of a piston disc and that of a spring washer, and fitting and holding an oil seal ring in this ring groove. CONSTITUTION:Through holes 16, 33 are connected concentrically with each other, and ring lips 21, 24 are confronted with each other, by fitting the flange 23 of a spring seat on the outer circumferential surface of the flange 20 of a piston 11. A ring groove 29 which opens toward the center of the through holes 16, 33, is formed between the both lips 21, 24, and an inside oil seal ring 17 is fitted and held in this ring groove 29. In this way, the spring seat can be also used as a member for forming an oil sealing mechanism, integration can be performed, and mechanical reliability is raised.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a sheet metal piston for a transmission in a vehicle, and more particularly to an inner oil seal mechanism for a clutch drum housing the sheet metal piston.

Prior Art and its Problems For example, as shown in Japanese Patent Application Laid-open No. 49-68159, a conventional sheet metal piston 1 for a transmission (see FIG. 1) is fitted into a clutch drum 4, and The hydraulic pressure introduced at the bottom is applied to the bottom surface of the piston plate 2 of the piston l to push it up against the return spring, and as it is pushed up, a spline is formed on the clutch drum 4 at the end of the rim 3 around the piston plate. The clutch plate fitted in the rim 4' is pressed to obtain a clutch engaged state. Then, an oil seal ring 5 is arranged on the outer peripheral surface of the rim, and the ring 5 is brought into close contact with the inner peripheral surface of the spline-formed rim 4' of the clutch drum 4 to achieve an oil seal on the outside of the piston.
An oil seal ring 7 is arranged on the inner peripheral surface of the through hole 6 bored in the center of the piston plate 2, and the ring 7 is inserted into the through hole 6.
The piston is configured to tightly contact the outer circumferential surface of the shaft insertion tube 8 of the clutch drum 4 inserted therethrough, thereby creating an oil seal inside the piston.

Conventionally, however, when installing the outer oil seal ring 5 and the inner oil seal ring 7, mounting rings 9a and 9b each having an angled cross section are prepared as separate parts, and these are press-fitted into the body of the clutch drum 4 as shown in the figure. An annular groove is formed between the rising edges of the mounting rings 9a and 9b and the bent portion of the drum body, and the oil seal ring 5 is inserted into the annular groove.
, 7 is fitted, and both the inner and outer oil seal rings 5 and 7 require the production of a mounting ring as a separate part, and furthermore, it requires assembly man-hours for press-fitting the rings. This will lead to an increase in costs.

Furthermore, since a press-fitting mechanism is used for the mounting ring, which is a separate component, mechanical reliability may be reduced.

SUMMARY OF THE INVENTION As an object of the invention, the present invention provides a sheet metal piston for a transmission which is improved with regard to the oil seal mechanism, particularly the inner oil seal mechanism. That is, the inner oil seal mechanism is formed by utilizing the sheet metal body portion of the sheet metal piston and the spring seat that supports the sheet metal piston return screw, thereby creating a ringless mechanism that does not use the conventional mounting ring. This makes it possible to provide a highly reliable oil seal mechanism while reducing parts and assembly man-hours.

Structure of the Invention The present invention is constructed to achieve the above object, and as can be understood from the embodiments described later, a spring seat concentric with the piston plate is integrally assembled to the piston plate,
The through-hole at the center of the piston plate and the through-hole provided at the center of the spring seat are concentrically connected, and the annular lip provided at the periphery of the through-hole of the piston plate and the through-hole provided at the periphery of the spring seat are connected concentrically. The annular lip forms an annular groove that opens toward the center of both through holes, and an oil seal ring is fitted and held in the annular groove, so that the oil seal ring can be completely attached to the clutch drum without using the conventional press-fitting mechanism of the mounting ring. The present invention provides the above-mentioned inner oil seal mechanism which is simple and purposeful, and which enables a simple and purposeful oil seal mechanism to be constructed.

Embodiments of the Invention Below, embodiments of the present invention will be described in detail with reference to FIGS. 2 to 5.

In the same figure, reference numeral 11 indicates a sheet metal piston for actuating a clutch plate in a transmission.A rim 13 is bent around a piston plate 12 by press molding on the sheet metal piston 11, and this is used to press the clutch plate. Use as a means. In order to perform this pressing well, an annular U-shaped bent portion bent inward is formed at the tip of the rim portion, and this is used as a clutch plate pressing portion 4Q. Also, a through hole 16 is bored in the center of the piston plate 12,
A flange 20 is provided around the through hole 16 in the same direction as the rim 13.
The tip of the flange 20 is bent toward the center to form an annular lip 21.

On the other hand, a circular spring seat 22 of a sheet metal part having a through hole 33 concentric with the through hole 16 of the piston 11 in the center is formed, and a flange 23 is formed around the through hole 33 of the circular spring seat 22.
The tip of the flange 23 is bent toward the center to form an annular lip 24.

Furthermore, an annular path 2 is formed around the spring seat 22 between the flange 23 and the flange 23.
The spring receiving forming wall 26 forming the spring receiving forming wall 26 is bent at intervals, and the spring receiving forming wall 26 is bent into a semi-cylindrical shape in the diametrical direction at intervals,
Therefore, a spring receiving chamber 27 for each piston return spring is formed around the spring seat 22, defined by the flange 23, the spring receiving forming wall 26, and the seat plate 28 connecting the two, and communicated with each other by the annular path 25. do.

The spring seat 22 thus formed is placed inside the piston 11, and the seat plate 28 is overlapped with the piston plate 12 and spot welded to form an integral structure. At the same time, the seven flange 23 of the spring seat 22 is fitted to the outer peripheral surface of the flange 20 of the piston 11, and the through hole 16,
33 concentrically communicate with each other, and the annular lips 21 and 24
facing each other, and a through hole 16 is formed between both lips 21 and 24.
, 33 is formed, and the inner oil seal ring 17 is fitted and held in the annular groove 29. That is, the spring seat 22 also serves as an oil seal mechanism forming element.

Further, the present invention provides a rim 1 around the piston plate 12 as described above.
3 to form a clutch plate suppressing means, the base of the rim 13 is bent into a U-shape toward the inner peripheral surface, and an annular groove 32 is formed by the U-shaped curved wall 31 on the outer peripheral surface of the rim, The outer oil seal ring 15 is fitted into the annular groove 32.

Preferably, the U-shaped curved wall 31 has a structure in which a bent piece thereof is folded over the outer circumferential edge surface of the piston plate 12, as shown in FIG.

FIG. 5 shows a state in which the piston 11 made of sheet metal and constructed as described above is assembled into a clutch drum 14 also made of sheet metal.

The clutch drum 14 has a spline formed rim 1 on the bottom plate 36.
4' is bent and formed, and a clutch plate is incorporated into the inner circumferential surface of the spline-formed rim 14', and the piston 1 made of the sheet metal
The rim 13 of the rim 1 is disposed on the edge of the rim 1.

In the figure, 38 is a drive plate that forms a clutch plate.
39 is the driven plate, 40 is a retaining plate, and 41 is a snap ring that prevents the clutch plate from coming off.

A shaft insertion tube 18 is bent in the center of the clutch drum 14, and the assembly of the sheet metal piston 11 and spring seat 22 is inserted into the outer peripheral surface of the shaft insertion tube 18 through its through holes 16, 33. and penetrate it.

As described above, the piston 11 is attached to the inner bottom of the clutch drum 14.
The assembly of the spring seat 22 is fitted, and while the inner oil seal ring 17 is brought into close contact with the outer circumferential surface of the shaft insertion tube 18, the outer oil seal ring 15 is attached to the inner circumferential surface of the base of the spline-forming rim 14', That is, it is brought into close contact with the inner circumferential surface of the base of the rim 14' where the spline does not extend.

Then, the drive plate 38 and the driven plate 39, which are clutch plates incorporated in the spline forming rim 14' of the oil latch drum 14 introduced into the inner bottom section of the clutch drum 14, are pressed to form the engaged state of the clutch.

34 indicates a piston return spring, one end of which is supported by the seat plate 2B accommodated in the spring receiving chamber 27 of the spring seat 22 assembled to the piston 11, and the other end supported by the shaft of the clutch drum 14. Another spring seat 37 attached to the insertion tube 18
It is supported in a compressed state between both spring seats 22 and 37, and its elastic force always gives return elasticity to the sheet metal piston 11.

The piston 11 is moved by the hydraulic pressure in the direction of pushing up the clutch plate against the elastic force of the spring 34, and when the hydraulic pressure is released, it returns to the inner bottom of the drum according to the elastic force of the spring 34, and the clutch is released. .

Inner oil seal ring 17 of the above-mentioned sheet metal piston 11
and the outer oil seal ring 15 is connected to the piston plate 12.
The piston 11 is driven by effectively sealing off the hydraulic pressure acting on the bottom surface of the piston 11.

Effects of the Invention As detailed above, the present invention relates to an oil seal mechanism, particularly an inner oil seal mechanism, in a sheet metal piston for a transmission, and provides a sheet metal sheet metal that is improved in both manufacturing and functional aspects. We can provide manufactured pistons.

That is, the present invention relates the formation of the inner oil seal mechanism to the use of a sheet metal body portion of a sheet metal piston and a spring seat that supports a sheet metal piston return spring, and a spring seat that is concentric with the piston plate on the piston plate. The through hole in the center of the piston plate and the through hole provided in the center of the spring seat are connected concentrically, and the annular lip provided around the through hole in the piston plate and the spring seat are assembled together. An annular lip provided on the periphery of the through hole forms an annular groove that opens toward the center of both the through holes, and the oil seal ring is fitted and held in the annular groove, so that it is not necessary to use a conventional mounting ring. By configuring a ringless mechanism that does not use a ring, it is possible to reduce parts and assembly man-hours, and to provide a highly reliable oil seal mechanism.

That is, it is possible to reduce the conventional process of preparing the mounting ring to be press-fitted into the piston plate and press-fitting it, and to achieve an integral structure of the sheet metal piston and the inner oil seal ring, and to obtain an accurate oil sealing effect with a simple configuration. A highly reliable oil seal mechanism can be provided without causing mechanical reliability deterioration associated with the conventional press-fitting of a separate mounting ring, and in addition, it is possible to achieve cost reduction and weight reduction, which are highly demanded in vehicles.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional sheet metal piston for a transmission, and Fig. 2 and subsequent figures show embodiments of the present invention. Figure 3 is an exploded perspective view of the piston, Figure 4 is an assembled perspective view of the piston with the oil seal ring removed, and Figure 5 is a sectional view showing the main parts of a transmission in which the piston is assembled into a clutch drum. It is. 11... Piston made of sheet metal, 12... Piston plate,
14... Clutch drum, 16.33... Penetration hole,
17...Inner oil seal ring, 18...Shaft insertion tube, 22...Spring seat, 21.24...Annular lip,
26... Spring receiving forming wall, 27... Spring receiving chamber, 28...
... Seat plate, 29... Annular groove, 34-... Piston return spring. 11th! ! Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) A spring seat that is concentric with the piston plate is integrally assembled on the piston plate, and the through hole in the center of the piston plate and the through hole provided in the center of the spring seat are concentrically connected, and the An annular lip provided at the periphery of the through hole and an annular lip provided at the periphery of the through hole of the spring seat form an annular groove opening toward the center of both the through holes, and an oil seal ring is installed in the annular groove. A sheet metal piston for a transmission, which is characterized by being fitted and retained. (2) The invention according to claim 1, wherein the spring seat has a plurality of spring receiving chambers for each piston return spring arranged concentrically.