JP2015102116A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deformation resulting in breakage of a piston seal.SOLUTION: The sealing device comprises: an annular piston seal 11 moving to one axial side by fluid pressure and pressurizing a disc C1 of a disc clutch C; and an annular cancel plate 12 arranged on one axial side of the piston seal 11 while being opposed to the piston seal 11. The piston seal 11 has an annular part 11a, an outer cylinder part 11c for pressurizing the disc C1, and an inner cylinder part 11b. A stopper member 32 for stopping the inner cylinder part 11b from moving one axial side against the fluid pressure by sandwiching it between an inner peripheral side face of the cancel plate 12 an a tip of the inner cylinder part 11b while the outer cylinder part 11c reaches a stroke end on one axial side so as to prevent excessive deformation of the piston seal 11 is provided between the inner peripheral side face of the cancel plate 12 and the tip of the inner cylinder part 11b.

Description

  The present invention relates to a sealing device used as a clutch piston for an automatic transmission such as an automobile.

  An automatic transmission such as an automobile has a power interrupting mechanism including a disk clutch for each of a plurality of planetary gear sets for determining a gear ratio, and each of the power interrupting mechanisms activates the disk clutch. A sealing device having a function of a clutch piston is incorporated (for example, see Patent Document 1).

FIG. 2 shows a conventional example of the sealing device 41, which is arranged inside an annular housing 42 provided in the power connection portion. In FIG. 2, the housing 42 includes a cylinder portion 43 in which an annular sealing device 41 is inserted, and an outer side that extends from one end of the outer peripheral wall 43 a in the axial direction of the cylinder portion 43 and houses the disc clutch 44. And a cylindrical portion 45.
The sealing device 41 forms a hydraulic chamber 46 with the housing 42 and moves in the housing 42 to one side in the axial direction by hydraulic pressure to press the disc 44a of the disc clutch 44, thereby driving the disc clutch 44 in a power transmission mode. An annular bonded piston seal 47, an annular cancel plate 48 disposed on one side in the axial direction facing the bonded piston seal 47, and the bonded piston seal 47 and the cancel plate 48. And a return spring 49 that is interposed therebetween and urges them in the direction of separating them in the axial direction.

  The bonded piston seal 47 has a concave cross section and is thinned for weight reduction. The bonded piston seal 47 includes an annular portion 47a facing the bottom wall 43b of the cylinder portion 43, and an inner cylindrical portion extending from the inner peripheral edge of the annular portion 47a to one side in the axial direction along the inner peripheral wall 43c of the cylinder portion 43. 47b and an outer cylindrical portion 47c extending from the outer peripheral edge of the annular portion 47a to the one axial side along the outer peripheral wall 43a of the cylinder portion 43. As shown in the cross-sectional view of FIG. 2, the connection portion between the annular portion 47a and the inner cylindrical portion 47b is an inner bent portion 47d having a curved cross section. The connecting portion between the annular portion 47a and the outer cylindrical portion 47c is an outer bent portion 47e having a bent cross section. The cross-sectional shape of the bonded piston seal 47 is changed at each of the bent portions 47d and 47e. An inwardly bent portion 47f that protrudes inward in the radial direction is formed at the tip of the inner cylindrical portion 47b. The inwardly bent portion 47f is the inner peripheral portion of the cancel plate 48 in the axial direction even when the base portion 50a of the seal member 50 and the outer cylindrical portion 47c reach the stroke end (final pressing position) on one axial side. It faces the inner peripheral part of the cancel plate 48 through a large gap 51 that does not come into contact with the cancel plate 48. An outwardly bent portion 47g protruding outward in the radial direction is formed at the tip of the outer cylindrical portion 47c.

JP 2008-256056 A

When power is transmitted by the disk clutch 44, hydraulic oil is supplied into the hydraulic chamber 46, the bonded piston seal 47 is moved to one side in the axial direction, and the disk of the disk clutch 44 is moved by the outward bent portion 47 g of the outer peripheral portion. 44a is pressed, and the disc clutch 44 is set to the power transmission mode. At this time, a moment M1 that presses the bonded piston seal 47 in the axial direction about the outward bent portion 47g acts on the bonded piston seal 47 due to the hydraulic pressure of the hydraulic oil.
By the way, as described above, conventionally, between the inwardly bent portion 47f of the bonded piston seal 47 and the inner peripheral portion of the cancel plate 48, the outer cylindrical portion 47c is on the one side in the axial direction with respect to the axial direction. Since the large gap 51 is formed so that the inward bent portion 47f does not contact the inner peripheral portion of the cancel plate 48 even when the stroke end is reached, large elastic deformation of the bonded piston seal 47 is allowed. It was. Therefore, in the bonded piston seal 47 whose thickness is reduced for weight reduction by the moment M1, the inwardly bent portion 47f of the inner peripheral portion thereof extends in the axial direction toward the inner peripheral portion of the cancel plate 48. Moving elastic deformation occurs. At the same time, stress is generated inside the bonded piston seal 47, but at each of the bent portions 47d and 47e of the bonded piston seal 47 where the cross-sectional shape is changed, the stress concentration increases locally. Happens.

However, when the elastic deformation of the bonded piston seal 47 increases, the stress generated in each of the bent portions 47d and 47e where the stress concentration occurs in the bonded piston seal 47 increases, and as a result, by repeating the elastic deformation, Cracks were likely to occur at the bent portions 47d and 47e. In addition, the large elastic deformation of the bonded piston seal 47 includes elastic deformation due to oscillation (movement) on the inner peripheral side with the outer bent portion 47e as the center (fulcrum). The generated stress was large, and cracks were particularly likely to occur in the outer bent portion 47e. The cracks caused damage (fatigue failure) of the bonded piston seal 47.
This invention is made | formed in view of such a situation, and it aims at providing the sealing device which can prevent the elastic deformation which leads to the failure | damage of a piston seal.

  In order to achieve the above object, the present invention provides an annular piston seal that moves the disk clutch in one axial direction by fluid pressure and presses the disk of the disk clutch to make the disk clutch a power transmission mode, and this piston seal. An annular cancel plate disposed on one side in the axial direction of the piston seal in a state of being opposed to the piston seal, wherein the piston seal includes an annular portion extending in the radial direction and an outer peripheral side of the annular portion An outer cylindrical portion that extends to one side in the axial direction and presses the disk, and an inner cylindrical portion that extends from the inner peripheral side of the annular portion to the one axial side, and a side surface on the inner peripheral side of the cancel plate; Between the tip of the inner cylindrical portion, the outer cylindrical portion reaches the stroke end on one axial side, and the side surface on the inner peripheral side of the cancel plate and the front A stopper member for preventing excessive elastic deformation of the piston seal by stopping the movement of the inner cylindrical portion against one end in the axial direction against the fluid pressure. It is characterized by providing.

According to this configuration, the piston seal is moved to one side in the axial direction by the fluid pressure, the disk of the disk clutch is pressed by the outer cylindrical portion of the piston seal, and the disk clutch is set in the power transmission mode. Along with the movement of the seal, the stopper member is sandwiched between the inner peripheral side surface of the cancel plate and the distal end portion of the inner cylindrical portion, so that the movement of the distal end portion of the inner cylindrical portion to one axial side is fluid. Stopped against pressure.
As described above, since the movement of the tip of the inner cylindrical portion of the piston seal is suppressed by the stopper member, excessive (large) elastic deformation that leads to breakage of the piston seal due to the moment is prevented.

The stopper may be formed of an elastic material.
According to this configuration, the impact when the piston seal comes into contact with the stopper is alleviated or absorbed by the elastic deformation of the stopper, and the generation of abnormal noise due to the impact can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the sealing device which can prevent the elastic deformation which leads to the failure | damage of a piston seal can be provided.

It is sectional drawing which shows the sealing device concerning embodiment of this invention. It is sectional drawing which shows the conventional sealing device.

Next, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing a power interrupting mechanism of an automatic transmission for an automobile in which a sealing device according to the present invention is used.
In FIG. 1, a power transmission mechanism 1 includes a disk clutch C for intermittently transmitting power to a planetary gear set (not shown), and a sealing device 10 having a function of a clutch piston for operating the disk clutch C. And the housing 20 which accommodates these inside is provided.
The housing 20 is an annular member formed in a concave cross section that opens to one side in the axial direction by sheet metal press molding or the like using, for example, a hot rolled steel plate or the like, and an annular sealing device 10 is inserted and disposed therein. The cylinder portion 21 and an outer cylindrical portion 22 that accommodates the disc clutch C extending from one axial end of the outer peripheral wall 21a of the cylinder portion 21 are provided.

  The sealing device 10 is an annular bonded piston seal 11 inserted into the cylinder portion 21 and defining the first oil chamber R1 with the cylinder portion 21, and is opposed to the bonded piston seal 11. An annular cancel plate (balancer) 12 disposed on one side in the axial direction in the state is provided, and a return spring 13 interposed between the bonded piston seal 11 and the cancel plate 12.

  The bonded piston seal 11 is, for example, an annular member having a concave cross section formed by hot die forging and cutting using machine structural steel, and has a reduced thickness for weight reduction. The bonded piston seal 11 is opposed to the bottom wall 21b of the cylinder portion 21 and extends in the radial direction. The bonded piston seal 11 extends from the inner peripheral edge of the annular portion 11a to the one axial side along the inner peripheral wall 21c of the cylinder portion 21. An inner cylindrical portion 11b and an outer cylindrical portion 11c extending from the outer peripheral edge of the annular portion 11a along the outer peripheral wall 21a of the cylinder portion 21 to one side in the axial direction are provided. As shown in the cross-sectional view of FIG. 1, the connecting portion between the annular portion 11a and the inner cylindrical portion 11b is an inner bent portion 11d having a curved section. The connecting portion between the annular portion 11a and the outer cylindrical portion 11c is an outer bent portion 11e having a bent cross section. The cross-sectional shape of the bonded piston seal 11 is changed at each of the bent portions 11d and 11e. On the surface of the annular portion 11a on the cancel plate 12 side, 3 to 6 concave portions 11f having a depth of about 0.5 mm are arranged at equal intervals in the circumferential direction. On the surface of the annular portion 11a on the first oil chamber R1 side, protruding portions 11g corresponding to the recessed portions 11f and protruding about 0.5 mm are arranged at equal intervals in the circumferential direction. An inwardly bent portion 11h that protrudes radially inward is formed at the tip of the inner cylindrical portion 11b.

To the bonded piston seal 11, annular first and second seal members 14, 31 that seal between the bonded piston seal 11 and the cylinder portion 21 are fixed. The first and second seal members 14 and 31 are formed of an elastic member such as synthetic rubber. The first seal member 14 is vulcanized and bonded to the outer peripheral portion of the annular portion 11a and the side surface on the first oil chamber R1 side of the outer bent portion 11e, and the base portion 14a bonded to the annular portion 11a and the like, and the outer bent portion The seal lip 14b is slidably in contact with the inner peripheral surface of the outer peripheral wall 21a by extending from 11e to the outer peripheral side. The second seal member 31 is vulcanized and bonded to the side surface on the first oil chamber R1 side of the inner peripheral portion of the inner cylindrical portion 11b and the inwardly bent portion 11h, and the base portion 31a bonded to the inner cylindrical portion 11b and the like. And a seal lip 31b that slidably contacts the outer peripheral surface of the inner peripheral wall 21c by extending from the inner peripheral portion of the inwardly bent portion 11h to the inner peripheral side. One end of the base portion 31a in the axial direction is externally fitted to the inwardly bent portion 11h.
The first and second seal members 14 and 31 seal the first oil chamber R <b> 1 by sealing between the bonded piston seal 11 and the cylinder portion 21.

  The inner peripheral wall 21c of the cylinder part 21 is provided with a supply port 21c1 for supplying hydraulic oil to the first oil chamber R1. The bonded piston seal 11 can reciprocate in the cylinder portion 21 in the axial direction by controlling the hydraulic pressure of the hydraulic oil supplied from the supply port 21c1 to the first oil chamber R1. The hydraulic pressure of the hydraulic oil is 1.4 to 2 MPa.

  An outwardly bent portion 11 i that protrudes radially outward and presses the disk clutch C is formed at the tip of the outer cylindrical portion 11 c of the bonded piston seal 11. The bonded piston seal 11 is reciprocated in the axial direction in the cylinder portion 21 by the hydraulic pressure of the hydraulic oil, thereby pressing the disc clutch C with the pressing surface 11j of the outward bent portion 11i, or releasing the press, The disc clutch C is switched between a power transmission mode and a power transmission disconnect mode.

  Similar to the bonded piston seal 11, the cancel plate 12 is an annular member formed by die forging and cutting using machine structural steel. The cancel plate 12 is a second member between the bonded piston seal 11 and the housing 20. An oil chamber R2 is defined. The cancel plate 12 connects the large-diameter annular portion 12a located on the inner peripheral side of the bonded piston seal 11 and the intermediate annular portion 12b located on one end side in the axial direction from the large-diameter annular portion 12a. A cylindrical portion 12c, a small-diameter annular portion 12d positioned closer to one end in the axial direction than the intermediate annular portion 12b, and an annular coupling portion 12e that connects the intermediate annular portion 12b and the small-diameter annular portion 12d in the axial direction are provided.

The inner peripheral end of the small-diameter annular portion 12d is externally fitted to the inner cylindrical portion 23 of the housing 20, and the movement to one side in the axial direction is restricted by the stopper 15 fixed to the inner cylindrical portion 23. Yes.
An annular third seal member 16 that seals between the cancel plate 12 and the bonded piston seal 11 is fixed to the outer peripheral end of the large-diameter annular portion 12a. The third seal member 16 is vulcanized and bonded to the outer peripheral end portion of the large-diameter annular portion 12a using an elastic member such as synthetic rubber, and extends to the outer peripheral side so that the outer cylindrical portion 11c of the bonded piston seal 11 It has a seal lip 16a in sliding contact with the inner peripheral surface.
The third seal member 16 seals the second oil chamber R2 by sealing between the cancel plate 12 and the bonded piston seal 11.

  A metal annular stopper member 32 is fixed to the outer peripheral portion of the small-diameter annular portion 12d of the cancel plate 12 and the surface of the connecting portion 12e on the second oil chamber R2 side. The stopper member 32 faces the inwardly bent portion 11h of the bonded piston seal 11 with a gap 33 in the axial direction in the power transmission disconnection mode of the disk clutch C, and also in the power transmission mode of the disk clutch C. , Contact with the inwardly bent portion 11h. The size of the gap 33 is about 0.3 to 0.5 mm. The stopper members 32 do not have to be annular, and a plurality of stopper members 32 may be arranged on the inner peripheral portion of the cancel plate 12 at equal intervals in the circumferential direction (not necessarily at equal intervals).

  The return spring 13 is interposed between the bonded piston seal 11 and the cancel plate 12 by abutting against the annular portion 11a of the bonded piston seal 11 and the intermediate annular portion 12b of the cancel plate 12. It is energized in the direction away from the direction. When the return spring 13 releases the pressure from the state where the bonded piston seal 11 moves to the one side in the axial direction and presses the disc clutch C, the return spring 13 moves the bonded piston seal 11 in the other axial direction by the biasing force. Move quickly to the side.

  The disk clutch C is configured by superimposing a large number of disks C1. When the disk clutch C is pressed by the bonded piston seal 11, the disks C1 are pressure-bonded, and the disk clutch C enters a power transmission mode. Power is transmitted to. On the other hand, when the pressing is released, the disk clutch C enters the power transmission disconnect mode and disconnects the power transmission. That is, the sealing device 10 can actuate the disk clutch C by the reciprocating movement of the bonded piston seal 11 in the axial direction to interrupt the transmission of power by the disk clutch C. As a clutch piston in the power transmission mechanism 1 It has the function of

According to the above configuration example, when the disc clutch C is in the power transmission cut mode, as shown in FIG. 1, the inwardly bent portion 11 h of the bonded piston seal 11 has the base portion 31 a of the second seal member 31 in the axial direction. Further, the stopper member 32 provided on the inner peripheral portion of the cancel plate 12 is opposed to the stopper plate 32 via the gap 33.
When power is transmitted by the disk clutch C, hydraulic oil is supplied to the first oil chamber R1, the bonded piston seal 11 is moved to one side in the axial direction, and the outward bent portion 11i of the outer peripheral portion thereof is moved. Thus, the disk C1 of the disk clutch C is pressed to set the disk clutch C to the power transmission mode.

At this time, as the bonded piston seal 11 moves in one axial direction, the inwardly bent portion 11h of the bonded piston seal 11 comes into contact with the stopper member 32, and one of the inwardly bent portions 11h in the axial direction. The movement to the side is stopped against the hydraulic oil pressure.
If the outward bent portion 11i of the bonded piston seal 11 reaches the stroke end (final pressing position) by the pressing stroke of the disc clutch C before this stop, from this reaching to the stop. In the meantime, the moment M which presses the bonded piston seal 11 to the one side in the axial direction about the outward bent portion 11i acts on the bonded piston seal 11 by the hydraulic pressure of the hydraulic oil.

  Accordingly, the bonded piston seal 11 whose thickness is reduced for weight reduction has an inwardly bent portion 11h on its inner peripheral portion that is elastically deformed so as to move in the axial direction toward the inner peripheral portion of the cancel plate 12. Occurs. At the same time, a stress is generated inside the bonded piston seal 11, but in each of the bent portions 11 d and 11 e, which are changed portions of the cross-sectional shape, in the bonded piston seal 11, the stress concentration is locally increased. Happens.

In this case, in this example, since the movement of the inwardly bent portion 11h of the bonded piston seal 11 is stopped by the stopper member 32 as described above, excessive (large) elasticity of the bonded piston seal 11 is obtained. Deformation is prevented.
As a result, the stress generated in each of the bent portions 11d and 11e where the stress concentration occurs in the bonded piston seal 11 does not increase as in the prior art, and as a result, the bent portions 11d and 11e are cracked by repeated elastic deformation. Can be suppressed, and damage (fatigue failure) of the bonded piston seal 11 can be prevented.

  In the above embodiment, the stopper member 32 is made of metal, but it may be formed of an elastic member such as synthetic rubber. In this case, the thickness of the stopper member 32 is set to a thickness that stops the movement of the inwardly bent portion 11h in a state where the stopper member 32 is elastically contracted to one side in the axial direction at the stroke end of the outwardly bent portion 11i. . In this way, the impact when the bonded piston seal 11 comes into contact with the stopper member 32 is alleviated or absorbed by the elastic deformation of the stopper member 32, and the generation of noise due to the impact can be suppressed. When rubber is used as the constituent material of the stopper member 32, for example, hard rubber having a rubber hardness of 80A or more is used.

  The fixing method of the stopper member 32 to the cancel plate 12 in the above case includes (1) a method in which the stopper member 32 is vulcanized and bonded to the cancel plate 12, and (2) one of the cancel plate 12 and the stopper member 32 and the other. There is a method in which a convex portion protruding to the side is formed and a corresponding concave portion is formed on the other side, and the convex portion is fitted (fitted) into the concave portion while the stopper member 32 is elastically deformed. The convex part and the concave part may be formed over the entire circumference, or may be formed in a plurality at equal intervals in the circumferential direction (not necessarily at equal intervals). When the convex portion or the concave portion is formed on the cancel plate 12, it is formed by pressing and punching (striking).

  In the above-described embodiment, the stopper member is provided in the cancel plate. However, the stopper member may be provided in a bonded piston seal or other members. In the above-described embodiment, an example in which the present invention is applied to a power interrupt mechanism of an automatic transmission for an automobile in which a sealing device is used has been described. However, the present invention is not limited to such a configuration.

  It goes without saying that various design changes and modifications can be made within the scope of the appended claims. That is, the embodiment disclosed in this specification is merely an example, and the present invention is not limited to the embodiment described above. The scope of the present invention is indicated by the appended claims after taking into account the description of the present specification, and includes all modifications within the meaning and scope equivalent to the words described therein.

10: sealing device, 11: bonded piston seal, 11a: annular portion, 11b: inner cylindrical portion, 11c: outer cylindrical portion, 12: cancel plate, 20: housing, 32: stopper member, 33: gap, C: disc Clutch, C1: disc

Claims (2)

An annular piston seal that makes the disk clutch a power transmission mode by moving to one side in the axial direction by fluid pressure and pressing the disk of the disk clutch, and a shaft of the piston seal in a state of being opposed to the piston seal A sealing device comprising an annular cancel plate arranged on one side of the direction,
The piston seal includes an annular portion extending in the radial direction, an outer cylindrical portion that extends from the outer peripheral side of the annular portion to the one axial side, and presses the disk, and from the inner peripheral side of the annular portion to the one axial side. An inner cylindrical portion extending,
Between the side surface on the inner peripheral side of the cancel plate and the tip end portion of the inner cylindrical portion, the side surface on the inner peripheral side of the cancel plate and the outer cylindrical portion reach the stroke end on one axial side. A stopper member for preventing excessive elastic deformation of the piston seal by stopping the movement of the inner cylindrical portion against one end in the axial direction against the fluid pressure. A sealing device comprising: The sealing device according to claim 1, wherein the stopper is made of an elastic material.

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