JPH0134744Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a clutch device for an automatic transmission, and more specifically, it is equipped with a piston made of sheet metal, and a seal is attached to the peripheral end of the piston by heat welding. This invention relates to a clutch device for an automatic transmission.

(Prior Art) Automatic transmissions used in automobiles and the like are equipped with a hydraulically operated clutch device for shifting gears. In this clutch device, an annular piston is movably fitted into a cylindrical space in a casing usually formed by a clutch drum, etc., and a seal is placed around the periphery of the piston to make sealing contact with the casing. A member is provided.
When hydraulic oil is pressurized between the clutch drum and the piston, the piston moves, creating a frictional force between the clutch plate and clutch disk, which are spline-connected to the clutch drum and clutch hub, respectively, and applies braking. ing. Conventionally,
Pistons used to be manufactured by casting, but in order to reduce cost and weight, pistons that are press-formed from metal plates are being proposed today. However, when a piston made of sheet metal is used, a problem arises in that attachment of the seal member is extremely difficult. For example, if a retaining groove is formed in the piston and a sealing member is fitted into the retaining groove to be attached, the shape of the piston becomes complicated, problems arise in molding, and the length in the axial direction becomes long. Further, when attempting to attach the seal member to the peripheral edge of the piston using an adhesive, cleaning of the attachment portion is required, and the life of the adhesive is short, resulting in durability problems. Furthermore, as a solution to these problems, Japanese Patent Laid-Open No. 49-135068 discloses a piston in which a hole is provided at the edge of the piston and a sealing member is injection molded so that it can be firmly attached to the piston through the hole. Disclosed. However, in the piston disclosed in JP-A-Sho, the sealing member is provided by an injection molding method, which causes the problem that a large-scale injection device is required. Adhesion is poor, and the durability problem still remains unsolved.

(Purpose of the invention) The purpose of the invention is to provide a clutch device for an automatic transmission equipped with a piston made of sheet metal, which has excellent adhesion between the sealing member and the piston, and which can easily provide the sealing member to the piston. An object of the present invention is to provide a clutch device for a transmission.

(Structure of the invention) The clutch device for an automatic transmission of the present invention is a clutch device equipped with a piston made of sheet metal, and the clutch device has a U-shaped cross section and is fitted to each end face of the outer circumference and inner circumference of the piston. A sealing member having a groove is attached to the outer circumference and inner circumference of the piston by heat welding with the fitting groove fitted, thereby making it possible to attach the sealing member to the piston extremely easily. At the same time, it is possible to obtain the advantage that the sealing member adheres extremely well to the piston.

(Embodiment) Hereinafter, one embodiment of the clutch device for an automatic transmission according to the present invention will be explained with reference to the drawings.

FIG. 1 is a schematic diagram of an automatic transmission using the automatic transmission clutch device of the present invention.

In FIG. 1, reference numeral 1 indicates a crankshaft of an engine (not shown) which is an input shaft, and a torque converter 2 and a multi-speed gearing device 10 are arranged coaxially with this crankshaft 1 in order from the engine side. . The torque converter 2 includes a pump 3, a turbine 4, and a stator 5,
The pump 3 is fixed to the crankshaft 1. The stator 5 is connected to a fixed shaft 7 integrally connected to the case 11 of the multi-speed gearing device 10 via a one-way clutch 6.
rotate on top. The one-way clutch 6 allows the stator 5 to rotate in the same direction as the pump 3, but does not allow it to rotate in the opposite direction.

The multi-speed gear device 10 has a base end fixed to the crankshaft 1 and a distal end extending through the center of the multi-speed gear device to drive an oil pump 11' disposed on the side wall of the device. It has a central shaft 12 connected to the pump. This central axis 1
A hollow turbine shaft 13 has a base end connected to the turbine 4 of the torque converter 2, a distal end extending to the side wall of the multi-speed gear unit 10, and a hollow turbine shaft 13 rotatably supported by the side wall. It is provided. A Ravigneau type planetary gear unit 14 is provided on this turbine shaft 13.
consists of a small-diameter sun gear 15, a large-diameter sun gear 16 disposed on the side of the small-diameter sun gear 15 far from the engine, a long pinion gear 17, a short pinion gear 18, and a ring gear 19. First and second clutch devices 20 and 21 are arranged in parallel on the side of the planetary gear unit 14 that is far from the engine.
The first clutch device 20 connects and connects the power supply between the small diameter sun gear 15 and the turbine shaft 13 via the first one-way clutch 22. On the other hand, the second clutch device 21
is connected in parallel with the first clutch device 20 to connect and disconnect power transmission between the small diameter sun gear 15 and the turbine shaft 13. A first brake device 23 is arranged radially outward of the second clutch device 21. This first brake device 23 is a band brake, and includes a brake drum 23a connected to the large diameter ring 16 and a brake band 2 attached to the brake drum.
3b. A third clutch device 24 is disposed radially outward of the first clutch device 20 and on the side of the first brake device 23. ,
Brake drum 2 of the first brake device 23
Power transmission between the large-diameter sun gear 16 and the turbine shaft 13 is switched on and off via the large-diameter sun gear 16 and the turbine shaft 13.

A carrier 14a of the planetary gear unit 14 and a case 10a of the multi-speed gear device 10 are arranged radially outwardly of the planetary gear unit 14.
A second brake device 25 is arranged to engage and disengage the. The first and second brake devices 23
and 25, a second one-way clutch device 26 is disposed in parallel with the second brake device 25 for engaging and disengaging the carrier 14a and the case 10a. On the side of the planetary gear unit 14 on the engine side, a carrier 14a of the planetary gear unit and the turbine shaft 13 are arranged.
a fourth clutch device 2 for intermittent power transmission between
7 is placed. This fourth clutch device 2
An output gear 28 connected to a ring gear 19 is arranged on the side of the engine 7 on the engine side. In addition, the reference numeral 29 in the figure indicates the turbine shaft 1.
3 shows a lock-up clutch for directly connecting the crankshaft 1 to the crankshaft 1 without going through the torque converter 2.

Next, with reference to FIG. 2, the structure of each of the above-mentioned devices constituting the automatic transmission will be explained.

Second Clutch Device 21 The second clutch device 21 is spline-coupled to the turbine shaft 13 and includes a clutch drum 21a having a substantially U-shaped cross section. A clutch hub 21c is disposed inside the clutch drum 21a, and the clutch hub 21c is integrally supported by a support portion 21d splined to the small diameter sale gear 15. Clutch plates 21c and clutch discs 21b, which are alternately arranged, are spline-coupled to the clutch drum 21a and clutch hub 21c, respectively. clutch drum 21a
A piston 21f having a substantially U-shaped cross section is fitted into the inside of the clutch drum 21a. This piston 21
A hydraulic oil chamber 21g is formed between f and the support 21a, and by controlling the supply of hydraulic oil to this hydraulic oil chamber 21g, the clutch plate 21e and the clutch disc 21b are pushed. ,
Alternatively, the second clutch device 21 can be engaged and disengaged by releasing the clutch. In addition, as is clear from the figure, the support portion 2 of the clutch hub 21c
The base portion 1d constitutes the inner race of the first one-way clutch 22.

First clutch device 20 Piston 21f of the second clutch device 21
also serves as the clutch drum 20a of the first clutch device 20. A clutch hub 20c is disposed inside the clutch drum 20a, and the clutch hub 20c has a support portion 2 that forms the outer race of the one-way clutch 22 at its base.
It is integrally supported by 0d. The clutch drum 20a and clutch hub 20c are spline-coupled with alternately arranged clutch plates 21e and clutch discs 21b, respectively. A piston 20f is fitted inside the clutch disk 20a.
A hydraulic oil chamber 20 is provided between f and the clutch drum 20a.
g is formed. By controlling the supply of hydraulic oil to the hydraulic oil chamber 20g, the clutch plate 21e and the clutch disk 21b are pushed or released, and the first clutch device 2
0 engagement and disengagement. In the figure, reference numeral 20h indicates a return spring for the pistons 20f, 21f of the first and second clutch devices 20, 21.

Third Clutch Device 24 The third clutch device 24 includes a substantially U-shaped clutch drum 24a that is integral with the clutch drum 21a. A clutch hub 24c is disposed inside the clutch drum 24a, facing the clutch drum 24a.
4c is formed by an extension of the brake drum 23a of the first brake device 23. Clutch drum 24a and clutch hub 24c are gas spline connected to alternating clutch plates 24d and clutch discs 24b, respectively. A piston 24e is fitted inside the clutch drum 24a.
A hydraulic oil chamber 24 is located between the clutch drum 24a and the clutch drum 24a.
f is formed. By controlling the supply of hydraulic oil to the hydraulic oil chamber 24f, the clutch plate 24d and the clutch disk 21b are pressed or released, and the third clutch device 24 is engaged or disengaged. It's becoming like that. This third clutch device 24 includes a diaphragm-type return spring 24g for the piston 24e. The reason why a diaphragm type return spring is used in this third clutch device 24 is that this diaphragm type is thin and does not require a large space.

First Brake Device 23 The brake drum 23a of the first brake device 23 is supported by a support portion 23c that is integrally supported by the large diameter sun gear 16. Therefore, when this first brake device 23 is activated,
The large diameter sun gear 16 is fixed.

Second brake device 25 This second brake device 25 is a disc type brake, and its brake drum 25a
is the carrier 14a of the planetary gear unit 14.
It is supported by a support portion 25b that is integrally fixed to the support portion 25b. Therefore, this second brake device 2
3 is activated, the carrier 14a is fixed.

Fourth Clutch Device 27 This fourth clutch device 27 is an embodiment of the clutch device of the automatic transmission of the present invention. As clearly shown in FIG. 3, which is a partially enlarged view of FIG. Cylindrical drum inner 27
i, the inner periphery is joined to the outer periphery of the end of this drum inner 27i, and the turbine shaft 13
The clutch drum 27a has a U-shaped cross section and a circumferential edge bent in the direction. clutch drum 27
A plurality of spline-connected clutch plates 27d are provided inside the periphery of a, and a clutch hub 27 is disposed between the clutch plates 27d.
A plurality of clutch discs 27b are provided spline-coupled to c. The clutch plate 27d is pressed by an annular piston 27e against a diaphragm spring 27g functioning as a return spring.
This annular piston 27e is molded by stamping from a metal plate, and includes a clutch drum 27a and a drum inner 2.
It is designed to be able to slide in the space formed between it and 7i. As shown in FIG. 4, annular seal members 27h and 27h' are attached by heat welding to the end edges, that is, the outer and inner peripheral parts of the annular piston 27e, and the piston 27e and the clutch drum 27a are connected to each other by heat welding. This prevents leakage of the hydraulic oil that is pressurized and injected into the hydraulic oil chamber 27f between the two. These seal members 27h and 27h' are installed by fitting the seal members 27h and 27h' having fitting grooves with a U-shaped cross section to the outer and inner circumferential parts of the piston 27e, respectively, and then heating the piston. This is done by dissolving a portion of the sealing member. Therefore, the material for the sealing member of the present invention is one that can be melted by heating, and for example, acrylic rubber can be used as the material for this sealing member.

In this way, seal members 27h and 27h' are provided over the entire circumference of the outer and inner circumferences of the piston 27e, sealing the outer circumference of the piston 27e and the clutch drum 27a, and sealing the inner circumference of the piston 27e and the drum inner. 27i, the piston 27e and clutch drum 27
When hydraulic oil is pressurized between the piston 27
e moves to the left in the figure against the biasing force of the diaphragm spring 27g, and the clutch plate 27
d and the clutch disk 27b, and the clutch hub 27c is moved between the clutch drum 27a and the clutch disk 27b.
Rotate as one unit. In this embodiment, the clutch hub 27c is supported by the carrier 14a of the planetary gear unit 14, making it possible to transmit power between the turbine shaft 13 and the carrier 14a. On the other hand, when the hydraulic oil pressure is removed, the piston 27e is moved toward the clutch drum 27a by the diaphragm spring 27g, and the braking is released.

(Effect of the invention) The clutch device of the automatic transmission of the invention has a sealing member having a fitting groove with a U-shaped cross section fitted to each end face of the piston made of sheet metal. Since the seal member and piston are attached by heat welding in the original condition, the adhesion between the seal member and the piston is extremely high, which improves durability, and there is no need to provide a groove for fitting the seal member to the piston, so it can be easily attached to the shaft of an automatic transmission. The length in the direction can be shortened, and an automatic transmission suitable for front engine/front drive type automobiles can be obtained. In particular, according to the present invention, the bonding area between the piston and the sealing member can be secured without increasing the size of the clutch device, and the bonding strength can be further improved.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an automatic transmission using the automatic transmission clutch device of the present invention, and Fig. 2 is an axial cross-section showing the structure of the automatic transmission shown in Fig. 1 in detail. 3 is a partially enlarged view of FIG. 2, and FIG. 4 is a sectional view showing an example of a piston used in the clutch device of the present invention. 1...Crankshaft, 2...Torque converter, 10
...Multi-stage variable speed gear device, 13...Turbine shaft,
14... Planetary gear unit, 15... Small diameter sun gear, 16... Large diameter sun gear, 17... Long pinion gear, 18... Short pinion gear, 19... Ring gear, 20... First clutch device, 21... Second clutch device, 22...First one-way clutch device, 23...First brake device, 24...Third clutch device, 25...Second brake device,
26...Second one-way clutch, 27...Fourth clutch device, 27a...Clutch drum, 27b
...Clutch disk, 27c...Clutch hub, 2
7d...Clutch plate, 27e...Piston, 2
7f... Hydraulic oil chamber, 27g... Diaphragm spring, 27h, 27h'... Annular seal member, 27i
...Drum inner, 28...Output gear.

Claims (1)

[Scope of utility model registration request] An annular sheet metal piston is slidably fitted into a cylindrical space formed by a casing of the clutch device, and a sealing member is provided on an outer circumference and an inner circumference of the piston to make sealing contact with the casing. A clutch device for an automatic transmission in which the piston is moved by pressurizing hydraulic fluid into one of the spaces defined by the piston, thereby operating the clutch device,
The sealing member is provided with a fitting groove having a U-shaped cross section that is fitted into each end face of the outer circumferential portion and the inner circumferential portion of the piston, and is heated and welded with the fitting groove fitted to each of the end portions. A clutch device for an automatic transmission, characterized in that the clutch device is attached to the piston.