JP4578158B2 - Clutch piston for fluid transmission - Google Patents

Description

  The present invention relates to a clutch piston of a fluid transmission that is installed in, for example, an automobile.

  In a conventional fluid transmission, a hydraulic clutch mechanism is used. In this clutch mechanism, operating oil is supplied to a hydraulic chamber formed in a gap between the clutch piston and the clutch cylinder to move the clutch piston along the guide surface of the clutch cylinder and press the clutch plate. It is the structure to do.

  In such a hydraulic clutch mechanism, a seal ring that partitions the hydraulic chamber and the clutch cylinder side space (clutch plate arrangement space) is attached to the clutch piston. This seal ring is added to the outer diameter side of a core part having a cylindrical part and an annular plate part extending radially inward from one axial end thereof, and a corner part where the cylindrical part and the annular plate part of the core metal are connected. It is the structure which has the outer lip | sticker by which the sulfur bonding was carried out. The outer lip is in contact with a clutch cylinder facing the clutch piston. In this seal ring, an elastic body made of the same material as the outer lip is made to wrap around the inner surface of the annular plate portion in a film shape, and the metal clutch piston is brought into contact with the clutch piston. The operating oil is prevented from seeping out from the fitting surface of the seal ring with the metal cored bar (see, for example, Patent Document 1).

In the above conventional example, if the film-like elastic body is brought into pressure contact with the clutch piston by bringing the seal ring core metal into close contact with the clutch piston, the sealing performance of the fitting surface between the clutch piston and the core metal of the seal ring However, in order to do so, it is necessary to manage the assembly tolerance of the seal ring with respect to the clutch piston to be small.
JP 2003-139249 A

  SUMMARY OF THE INVENTION An object of the present invention is to improve as much as possible the sealing performance of a mating surface between a clutch piston of a fluid transmission and a seal ring attached thereto.

The clutch piston of the fluid transmission according to the present invention is accommodated in the annular space of the clutch cylinder so as to be slidable in the axial direction, and forms a hydraulic chamber between the clutch cylinder and the clutch piston. The fluid type transmission is slid in the axial direction to switch the fluid type transmission. A seal ring for separating the hydraulic chamber from the clutch cylinder side space is attached to the clutch piston, and this seal ring is fitted on the clutch piston. A cored bar to be attached, an outer lip attached to the cored bar and brought into contact with the clutch cylinder side, and a fitting surface of the cored bar attached to the clutch piston in an elastically deformed state. that has an inner lip, said metal core, and an annular plate portion extending the cylindrical portion and its axial end radially inward, the The inner lip is vulcanized and bonded to the inner diameter side of the inner surface, which is the surface that contacts the clutch piston, in the annular plate portion of the core metal, and the inner diameter side of the inner surface of the core metal is more shaft than the outer diameter side. The inner lip is disposed in a thin portion of the stepped portion, and the inner lip is elastically deformed when the inner lip is attached to the clutch piston. It is characterized by being accommodated within the direction width .

According to the present invention, the inner ring of the seal ring that is externally fitted to the clutch piston is provided with an inner lip that is pressed against the clutch piston in an elastically deformed state, instead of a film-like elastic body as in the prior art. Therefore, even if oil penetrates into the mating surface of the clutch piston and the core metal of the seal ring, this oil penetration is prevented. In particular, since the inner lip is pressed against the clutch piston in an elastically deformed state, the sealing performance can be easily ensured without reducing the assembly tolerance of the core metal of the seal ring with respect to the clutch piston as in the conventional example. In addition, the inner diameter side of the inner side surface of the cored bar has a stepped shape that recedes outward from the outer diameter side, and the inner lip is disposed at this stepped portion, so the protruding length of the inner lip is increased. As a result, the inner lip can be easily brought into pressure contact with the clutch piston even when the assembly cost (fitting allowance) of the core of the seal ring with respect to the clutch piston is shallow.

Preferably, before Symbol outer lip it can be a cylindrical portion of the metal core and the annular plate portion is assumed to have been vulcanization bonded to the outer diameter side of the corner portion which connects.

  According to the present invention, the tightness of the mating surfaces of the clutch piston and the seal ring can be made sufficient without managing the assembly tolerance of the seal ring with respect to the clutch piston severely.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view showing an upper half of a main part of a clutch piston mechanism of a fluid transmission, and FIG. 2 is a cross-sectional view showing an upper half of the seal ring of FIG.

  In the clutch mechanism of the fluid transmission shown in the figure, the gap between the clutch piston 1 and the clutch cylinder 2 is partitioned by a seal ring 3 to separate the clutch cylinder side space 4 and the hydraulic chamber 5.

  The clutch piston 1 and the clutch cylinder 2 are annular members manufactured by bending a metal plate, and both have substantially the same cross-sectional shape. Each of the clutch piston 1 and the clutch cylinder 2 is bent radially inward from one end of the large diameter cylindrical portions 11 and 21 to form the large diameter annular plate portions 12 and 22. The small-diameter cylindrical portions 13 and 23 are formed from the inner ends of the 22, and the small-diameter cylindrical portions 13 and 23 are further bent inward in the radial direction to form the small-diameter annular plate portions 14 and 24. .

  The clutch piston 1 is fitted on the inner diameter side of the clutch cylinder 2 via a predetermined opposing gap, and the clutch piston 1 is movable in the axial direction with respect to the clutch cylinder 2. The facing clearance between the clutch cylinder 2 and the clutch piston 1 is partitioned by a seal ring 3 attached to the clutch piston 1, thereby separating the clutch cylinder side space 4 and the hydraulic chamber 5.

  The operation of the clutch mechanism of such a fluid transmission will be described.

  The clutch piston 1 is elastically biased toward the clutch cylinder 2 by a coil spring (not shown). By supplying the operation oil to the hydraulic chamber 5, the clutch piston 1 is slid to the right side in FIG. The clutch piston 1 is slid to the left in FIG. By this sliding operation, a clutch plate (not shown) is pressed against the clutch disk so as to transmit power, or is pulled apart to interrupt power transmission.

  Here, the configuration of the seal ring 3 will be described in detail.

  The seal ring 3 is configured by vulcanizing and bonding an outer lip 32 and an inner lip 33 made of an elastic material to a cored bar 31. The cored bar 31 has a shape in which a radially inward annular plate part 35 is integrally formed at one end of the cylindrical part 34. The outer lip 32 is attached to the outer diameter side of the corner portion between the cylindrical portion 34 and the annular plate portion 35 in the core metal 31 so as to extend radially outward. The inner lip 33 is attached in a state of extending radially inward toward the clutch piston 1 on the inner diameter side of the inner surface of the annular plate portion 35 (the surface on the side contacting the clutch piston 1) of the core metal 31. ing.

  The inner diameter side of the inner side surface of the cored bar 31 is bent so as to have a stepped shape that recedes outward from the outer diameter side, and the stepped portion 36 is thinned from the inner side toward the outer side. An inner lip 33 is disposed on the thin portion 37 of the stepped portion 36. Thereby, since the protrusion length of the inner lip 33 can be made as long as possible, the contact tightening margin with respect to the clutch piston 1 can be increased. In other words, when the seal ring 3 is fitted and attached to the clutch piston 1, the inner lip 33 is pressed against the small-diameter annular plate portion 14 of the clutch piston 1 even when the fitting allowance (fitting depth) becomes shallow. It makes it possible to contact in the state.

  In the seal ring 3, the inner peripheral surface of the cylindrical portion 34 of the core metal 31 is in contact with the small diameter cylindrical portion 13 of the clutch piston 1, and the annular plate portion 35 of the core metal 31 is in contact with the small diameter annular plate portion 14 of the clutch piston 1. Installed in a state. In this state, the outer lip 32 is pressed against the inner peripheral surface of the small diameter cylindrical portion 23 of the clutch cylinder 2 while being elastically deformed, and the inner lip 33 is elastically deformed to the outer surface of the small diameter annular plate portion 14 of the clutch piston 1. Pressed in the state. Both lips 32 and 33 are provided with a predetermined tightening allowance so as to be elastically deformed. In addition, the inclination degree of both lips 32 and 33, a fastening margin, etc. are suitably managed as needed. However, in FIG. 1, the lips 32 and 33 are not elastically deformed so that the tightening allowance of the lips 32 and 33 can be easily understood.

  In this way, the seal ring 3 partitions the clutch cylinder side space 4 and the hydraulic chamber 5 with the outer lip 32, and seals the fitting surface between the core metal 31 and the clutch piston 1 with the inner lip 33. The oil is prevented from seeping out from the clutch cylinder side space 4 from 5.

  As described above, the core 31 of the seal ring 3 that is externally fitted to the clutch piston 1 is provided with the inner lip 33 that is pressed against the clutch piston 1 instead of the film-like elastic body as in the conventional example. Therefore, even if oil penetrates into the fitting surface between the clutch piston 1 and the core 31 of the seal ring 3, the oil is prevented from seeping out. In particular, since the inner lip 33 is pressed against the clutch piston 1 in a state of being elastically deformed, it is sufficient that the assembly tolerance of the core metal 31 of the seal ring 3 with respect to the clutch piston 1 is not reduced as in the conventional example. Sealability can be secured. That is, even if the assembly tolerance of the seal ring 3 with respect to the clutch piston 1 is not severely managed, oil can be reliably prevented from exuding from the fitting surface of the clutch piston 1 and the seal ring 3.

Sectional drawing which shows the upper half of the principal part in the best embodiment of the clutch piston mechanism of the fluid-type transmission which concerns on this invention. Sectional drawing which shows the upper half of the seal ring of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Clutch piston, 2 ... Clutch cylinder, 3 ... Seal ring, 31 ... Core metal, 32 ... Outer lip, 33 ... Inner lip

Claims (2)

A hydraulic chamber is formed in the annular space of the clutch cylinder so as to be slidable in the axial direction. A hydraulic chamber is formed between the clutch cylinder and the clutch cylinder. The hydraulic transmission is switched in the axial direction according to the hydraulic control for the hydraulic chamber. A clutch piston of a fluid transmission,
A seal ring that partitions the clutch cylinder side space from the hydraulic chamber is attached to the clutch piston,
The seal ring includes a metal core that is externally fitted to the clutch piston, an outer lip that is attached to the metal core and is in contact with the clutch cylinder, and a fitting that is fitted to the metal core and is attached to the clutch piston. An inner lip that is brought into contact with the mating surface in an elastically deformed state ;
The cored bar has a cylindrical part and an annular plate part extending radially inward from one axial end thereof, and the inner lip is a surface on the side of the annular plate of the cored bar that comes into contact with the clutch piston. Vulcanized and bonded to the inner diameter side of the inner surface,
The inner diameter side of the inner surface of the cored bar has a stepped shape that recedes outward in the axial direction from the outer diameter side, and the inner lip is disposed in a thin portion of the stepped portion and is attached to the clutch piston. In addition, the inner lip is accommodated within an axial width of the annular plate portion of the seal ring by elastic deformation . Before Symbol outer lip, the clutch piston of the hydraulic transmission according to claim 1 in which the cylindrical portion of the metal core and the annular plate portion, characterized in that it is bonded by vulcanization to the outer diameter side of the corner portion which connects .

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