JP2017207089A - Seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stable motion of a piston seal moving along an inner peripheral surface of a housing even if it has a simple configuration.SOLUTION: In a first range ar1 defined in such a way that either supply or discharge of oil to a piston hydraulic chamber is advantageous due to a presence of oil hole 101b of a housing 101 at an outer peripheral surface of a piston seal, a covering part 23 is covered at a prescribed covering thickness t1 thinner than a reference thickness, and in a second range ar2 defined in such a way that either supply or discharge of oil to the piston hydraulic chamber is more disadvantage than that of the first range ar1 at the outer peripheral surface of the piston seal, the covering part 23 is covered by a covering thickness t2 thicker than the reference thickness t1.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sealing device, and more particularly to a sealing device for a clutch piston mechanism used in an automatic transmission (AT (Automatic Transmission), CVT (Continuously Variable Transmission), etc.) for a vehicle such as an automobile.

  Conventionally, a sealing device for a clutch piston mechanism used in an automatic transmission of a vehicle such as an automobile includes a bonded piston seal, a canceller seal, and a return spring provided between the bonded piston seal and the canceller seal. .

  The bonded piston seal is a rubber lip vulcanization adhesion type piston seal used for fastening a multi-plate clutch provided inside a cylindrical clutch housing (hereinafter also referred to as “housing”). In the following description, the bonded piston seal is also referred to as a piston seal.

  The piston seal is generally composed of a metal ring that operates (reciprocates) in the axial direction of the housing according to the hydraulic pressure of hydraulic oil supplied to the inside of the housing in order to engage or release the multi-plate clutch of the automatic transmission. And a seal lip formed integrally with the metal ring.

  A piston hydraulic chamber is formed between the inner peripheral surface of the housing to which the piston seal is mounted and the piston seal, and hydraulic oil is supplied to the piston hydraulic chamber through an oil hole formed in the housing. .

  The piston seal moves in the axial direction while sliding on the inner peripheral surface of the housing in accordance with the hydraulic pressure supplied to the hydraulic oil, and a forward operation in which the clutch plate is fastened by a flange-like pressing member provided on the piston seal. When the supply hydraulic pressure is released, the return operation is repeatedly performed by moving the pressing member away from the clutch plate by the urging force of the return spring and returning to the original reference position (see, for example, Patent Document 1). .

JP 2006-242311 A

  However, in the sealing device having the above-described configuration, the oil hole of the housing is provided at a predetermined location due to restrictions such as other component layouts. For this reason, hydraulic oil is easily supplied or discharged at the piston seal portion facing the oil hole, whereas hydraulic oil is hardly supplied or discharged at the piston seal portion away from the oil hole, There was a situation where the piston seal tilted.

  Therefore, when the piston seal moves along the axial direction on the inner peripheral surface of the housing, if the piston seal is inclined, the operation may be biased. In this case, there has been a concern that a shift shock at the time of clutch engagement becomes large, abnormal noise is generated, or rattling occurs.

  In order to eliminate such concerns, conventionally, countermeasures have been taken by providing an elastic member such as a leaf spring between the pressing member provided on the piston seal and the clutch plate. In addition, the assembly man-hours increase.

  The present invention has been made in view of the above problems, and its object is to provide a piston seal that moves along the inner peripheral surface of the housing while having a simple configuration without increasing the number of parts and the number of assembly operations. To provide a sealing device that can stabilize movement.

  In order to achieve the above object, the sealing device (1) of the present invention is disposed inside the housing (101) so as to reciprocate along the axis (x) while facing the clutch member (60). An annular shape that has a piston lip (21, 22) that slides hermetically with an inner peripheral surface (101a) along the axis (x) of (101) and forms a piston hydraulic chamber (P1) together with the housing (101). The piston seal (10) and the clutch member (60) are pressed or separated according to the oil pressure supplied to the piston hydraulic chamber (P1) from the oil hole (101b) formed in the housing (101). The piston seal (10) is integrally fixed to the outer peripheral side end of the pressing portion (10i), and engages with an engaging recess (102) formed in the inner peripheral surface (101a). A protrusion (11) for preventing relative rotation of the piston seal (10) with respect to the housing (101), and an outer periphery of the piston seal (10) facing the inner peripheral surface (101a) of the housing (101). A cover portion (23) made of an elastic material that covers the surface, and the piston oil pressure chamber (101b) in the outer periphery of the piston seal (10) due to the presence of the oil hole (101b) of the housing (101). In the first range (ar1), where the supply or discharge of the oil to P1) is defined as advantageous, the coating (23) is coated with a predetermined coating thickness (t1) that is less than the reference thickness, Of the outer peripheral surface of the piston seal (10), it is defined that the supply or discharge of the oil to the piston hydraulic chamber (P1) is more disadvantageous than the first range (ar1). In the range of (ar2), characterized in that the cover portion (23) is coated with the reference thicker coating thickness than the thickness (t2).

  In the sealing device (200, 300) according to the present invention, the covering portion (23) includes the covering thickness (t1s, t1z) corresponding to the area of the oil hole (101f) or the number of the oil holes (101g, 101h). , T2).

  In the sealing device (1, 200, 300) according to the present invention, the covering portion (23) covered on the outer peripheral surface of the piston seal (10) has the first range (ar1, ar11, ar21) and the You may make it become non-uniform | heterogenous as a whole by each said coating thickness (t1, t1s, t1z, t2) according to a 2nd range (ar2, ar12, ar22).

  According to the present invention, it is possible to realize a sealing device that can stabilize the movement of the piston seal that moves along the inner peripheral surface of the housing, while having a simple configuration without increasing the number of parts and the number of assembly operations. .

It is a fragmentary sectional view in the section which meets the axis line which shows the state where the sealing device concerning a 1st embodiment of the present invention was equipped with the housing of a transmission. It is a top view which shows a structure when the piston seal of the sealing device which concerns on the 1st Embodiment of this invention is seen from the housing | casing side. It is a top view which shows a structure when the piston seal of the sealing device which concerns on the 2nd Embodiment of this invention is seen from the housing | casing side. It is a top view which shows a structure when the piston seal of the sealing device which concerns on the 3rd Embodiment of this invention is seen from the housing | casing side.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. Here, for convenience of explanation, the radial direction of the piston seal 10 of the sealing device 1 perpendicular to the axis x in FIG. Therefore, the outer peripheral side is the outer peripheral side of the piston seal 10, that is, the direction of the arrow a, and the inner peripheral side is the inner peripheral side of the piston seal 10, that is, the direction of the arrow b. Moreover, let the stroke direction of the piston seal 10 along the axis line x in the sealing device 1 be an arrow cd direction. Therefore, the housing side is defined as the direction of arrow c opposite to the multi-plate clutch 60 in the stroke direction (arrow cd direction) along the axis x of the piston seal 10. The multi-plate clutch side is defined as an arrow d direction in which the multi-plate clutch 60 exists in the stroke direction (arrow cd direction) along the axis x of the piston seal 10. Note that the axis x is the center of rotation of the drive shaft (not shown) and the housing 101.

  Hereinafter, the sealing device of the present invention will be described separately for each of the first to third embodiments.

<First Embodiment>
As shown in FIGS. 1 and 2, the sealing device 1 is mounted inside a housing 101 of the transmission. The sealing device 1 includes a piston seal 10, an elastic body portion 20 integrated with the piston seal 10, a return spring 30, and a canceller seal 40.

  The piston seal 10 is an annular member made of metal with the axis x of the housing 101 as the center. A piston hydraulic chamber P <b> 1 is formed between the piston seal 10 and the inner peripheral surface 101 a of the housing 101. An oil hole 101b communicating with the piston hydraulic chamber P1 is formed in the inner peripheral surface 101a of the housing 101. In this case, the oil hole 101 b is formed at an end portion on the inner peripheral side (arrow b direction) of the inner peripheral surface 101 a of the housing 101.

  The piston seal 10 slides on the inner peripheral surface 101a of the housing 101 along the axis line x in accordance with the hydraulic pressure of hydraulic oil such as ATF (Automatic Transmission Fluid) supplied through the oil hole 101b of the housing 101. However, it moves relative to the housing 101.

  The piston seal 10 is attached to the inner peripheral surface 101 a of the housing 101 together with the elastic body portion 20, and is rotated along with the rotation of the housing 101. Examples of the metal material of the piston seal 10 include stainless steel and SPCC (cold rolled steel), and are mainly SPFH (hot rolled steel) and SAPH (hot rolled steel). The piston seal 10 is manufactured by, for example, pressing or forging.

  The piston seal 10 includes an inner circumferential jaw portion 10a, an innermost circumferential cylindrical portion 10b, an innermost circumferential annular portion 10c, a central cylindrical portion 10d, a central annular portion 10e, an outer circumferential cylindrical portion 10f, and an outer circumferential ring. A portion 10g, an outermost cylindrical portion 10h, and a clutch pressing portion 10i are provided, and are integrally formed as a whole.

  The inner peripheral side jaw portion 10 a is an annular portion centering on the axis x, and a slight gap is formed between the end surface on the inner peripheral side (in the direction of arrow b) and the inner peripheral surface 101 a of the housing 101. Has been. The innermost cylindrical portion 10b has a cylindrical shape centering on the axis line x extending from the end portion on the outer peripheral side (arrow a direction) of the inner peripheral side jaw portion 10a along the axis x to the housing side (arrow c direction). Part.

  The innermost ring part 10c is an annular part centering on the axis line x extending from the end of the innermost cylinder part 10b on the housing side (arrow c direction) to the outer periphery side (arrow a direction). is there. The central cylindrical portion 10d is a cylindrical portion centering on the axis line x extending from the end on the outer peripheral side (arrow a direction) of the innermost ring portion 10c to the housing side (arrow c direction) along the axis line x. It is.

  The central annular part 10e is an annular part centering on the axis line x extending from the end of the central cylindrical part 10d on the housing side (arrow c direction) to the outer peripheral side (arrow a direction). The outer peripheral cylindrical portion 10f is centered on the axis x extending from the end on the outer peripheral side (arrow a direction) of the central annular portion 10e toward the multi-plate clutch side (arrow d direction) along the axis x. It is a cylindrical part.

  The outer peripheral side annular portion 10g is an annular portion centering on the axis line x slightly extending from the end of the outer peripheral side cylindrical portion 10f on the multi-plate clutch side (arrow d direction) to the outer peripheral side (arrow a direction). is there. The outermost peripheral cylindrical portion 10h is centered on the axis x extending from the outer peripheral end (arrow a direction) end of the outer peripheral ring portion 10g toward the multi-plate clutch side (arrow d direction) along the axis x. It is a cylindrical part.

  The clutch pressing part 10i is an annular part centered on the axis line x that slightly extends from the end of the outermost cylindrical part 10h on the multi-plate clutch side (arrow d direction) toward the outer peripheral side (arrow a direction). It is.

  This clutch pressing part 10i becomes a part which presses the multi-plate clutch 60 when it moves to the multi-plate clutch side (arrow d direction) along the axis x of the piston seal 10. Therefore, the multi-plate clutch 60 is engaged or released by moving the clutch pressing portion 10i together with the piston seal 10 in the stroke direction (arrow cd direction) along the axis x.

  A projecting portion 11 having a substantially rectangular shape in plan view extending from the outer peripheral end to the outer peripheral side (arrow a direction) is integrally formed on the outer peripheral end of the clutch pressing portion 10i on the outer peripheral side (arrow a direction). It is fixed. A plurality of protrusions 11 are equally arranged in the circumferential direction at the outer peripheral side end of the clutch pressing portion 10i.

  When the piston seal 10 is mounted on the inner peripheral surface 101a of the housing 101, the protrusion 11 is engaged with an engaging recess 102 formed on the inner peripheral surface 101a. As a result, the piston seal 10 prevents the piston seal 10 from rotating relative to the housing 101 during rotation about the axis x of the housing 101, and maintains a state where the piston seal 10 rotates with the rotation of the housing 101. .

  The elastic body portion 20 is a rubber-like elastic member that covers the outer peripheral surface of the piston seal 10 on the housing side (arrow c direction), and is integrated with the piston seal 10. The elastic body 20 moves inside the housing 101 along the axis x to the housing side (arrow c direction) or the multi-plate clutch side (arrow d direction) together with the piston seal 10. Examples of the elastic material of the elastic body portion 20 include nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), fluorine rubber (FKM), silicon rubber, and styrene butadiene rubber ( Synthetic rubber such as SBR) is used.

  The elastic body portion 20 includes an inner peripheral side seal lip 21, an outer peripheral side seal lip 22, and a covering portion 23.

  The inner circumferential side seal lip 21 extends from the inner circumferential side (arrow b direction) end of the inner circumferential side jaw portion 10a of the piston seal 10 along the axis x to the housing side (arrow c direction) and the inner circumferential side (arrow b). It is a part formed so as to protrude in the direction). The inner peripheral side seal lip 21 has a lip tip 21a that comes into contact with the inner peripheral surface 101a on the inner peripheral side (arrow b direction) of the housing 101 so as to slide along the axis x. .

  The outer peripheral side seal lip 22 protrudes from the outer peripheral side (arrow a direction) end of the central ring portion 10e of the piston seal 10 along the axis x to the housing side (arrow c direction) and the outer peripheral side (arrow a direction). It is the part formed so that. The outer peripheral side seal lip 22 has a lip front end portion 22a that comes into contact with the inner peripheral surface 101a on the outer peripheral side (in the direction of arrow a) of the housing 101 so as to slide along the axis x.

  The covering portion 23 connects the inner peripheral side seal lip 21 and the outer peripheral side seal lip 22, and covers the outer peripheral surface of the piston seal 10 on the housing side (in the direction of the arrow c) while facing the inner peripheral surface 101 a of the housing 101. It is the part to cover. The covering portion 23 is vulcanized and bonded to the casing side (arrow c direction) of the piston seal 10 in a state of being integrated with the inner peripheral side seal lip 21 and the outer peripheral side seal lip 22.

  As shown in FIG. 2, the portion of the piston seal 10 facing the oil hole 101b formed in the housing is supplied with oil from the piston hydraulic chamber P1 or the oil from the piston hydraulic chamber P1 due to the presence of the oil hole 101b. This is an area where discharge is easily performed. That is, the portion of the piston seal 10 that faces the oil hole 101b is advantageous for the operation of the piston seal 10, and thus the region including the portion is defined as the first first range ar1 of the piston seal 10.

  In the first range ar1, the stroke behavior of the piston seal 10 is sensitive according to the supply or discharge of oil to the piston hydraulic chamber P1. For this reason, the first range ar1 is set so that the space between the inner peripheral surface 101a of the housing 101 and the outer peripheral surface of the piston seal 10 is as wide as possible so that the behavior of the piston seal 10 is insensitive to oil supply or discharge. Then, the coating | coated part 23 is formed with the coating thickness of predetermined thickness t1 thinner than reference | standard thickness.

  On the other hand, the portion of the piston seal 10 that is not opposed to the oil hole 101b formed in the housing is not supplied with oil or discharged from the piston hydraulic chamber P1 due to the absence of the oil hole 101b. This is an area that is difficult to do. That is, the portion of the piston seal 10 that is not opposed to the oil hole 101b is disadvantageous for the operation of the piston seal 10, and therefore the region including the portion (the region other than the first range ar1) is the first portion of the piston seal 10. The range 2 is defined as ar2.

  In the second range ar2, the stroke behavior of the piston seal 10 is insensitive according to the supply or discharge of oil. For this reason, in order to make the behavior of the piston seal 10 sensitive to the supply or discharge of oil, the interval between the inner peripheral surface 101a of the housing 101 and the outer peripheral surface of the piston seal 10 is made as small as possible. Then, the covering portion 23 is formed with a covering thickness of a predetermined thickness t2 that is thicker than the reference thickness.

  However, the present invention is not limited to this, and all regions in the circumferential direction of the portion of the piston seal 10 facing the oil hole 101b formed in the housing 101 are defined as the first range ar1s, and in the first range ar1s The covering portion 23 may be formed with a covering thickness of a predetermined thickness t1 that is thinner than the reference thickness. In that case, in the second range ar2s other than the first range ar1s, it is only necessary that the covering portion 23 is formed with a coating thickness of a thickness t2 larger than the reference thickness.

  The covering portion 23 is formed with a plurality of convex portions 24 that are equally distributed in a convex shape toward the housing side (in the direction of the arrow c) at a portion corresponding to the innermost circumferential ring portion 10 c of the piston seal 10. Yes.

  Accordingly, when the piston seal 10 and the elastic body portion 20 are integrated and moved to the housing side (arrow c direction), the convex portion 24 of the elastic body portion 20 is located on the housing side of the housing 101 (arrow c direction). It contacts the inner peripheral surface 101a.

  Therefore, the piston seal 10 stops with the contact position of the convex portion 24 with respect to the inner peripheral surface 101a of the housing 101 as the stop position (top dead center). Thus, the presence of the convex portion 24 of the elastic body portion 20 prevents the entire surface of the covering portion 23 of the elastic body portion 20 from coming into close contact with the inner peripheral surface 101a of the housing 101, and the responsiveness of the piston seal 10 decreases. To prevent it.

  The canceller seal 40 is an annular metal plate that holds the return spring 30 together with the piston seal 10. The canceller seal 40 is a member fixed to the housing 101 via the snap ring 42, and rotates with the rotation of the housing 101 while being fixed to the housing 101.

  Examples of the metal material of the canceller seal 40 include stainless steel and SPCC (cold rolled steel), and are mainly SPFH (hot rolled steel) and SAPH (hot rolled steel). The canceller seal 40 is manufactured by, for example, pressing or forging.

  The canceller seal 40 includes an inner circumferential side annular part 40a, an inner circumferential side cylindrical part 40b, a central annular part 40c, an outer circumferential side cylindrical part 40d, and an outer circumferential side annular part 40e.

  An inner peripheral side annular portion 40 a of the canceller seal 40 is an innermost peripheral end portion on the inner peripheral side (arrow b direction) of the canceller seal 40, and is fixed to the snap ring 42.

  The inner peripheral cylindrical portion 40b extends from the outer peripheral end (arrow a direction) of the inner peripheral ring portion 40a toward the housing side (arrow c direction) and the outer peripheral side (arrow a direction) along the axis x. It is a cylindrical part centering on the said axis line x extended in the inclined state.

  The central annular portion 40c is an annular portion centering on the axis line x extending from the end of the inner peripheral cylindrical portion 40b on the housing side (in the arrow c direction) to the outer peripheral side (in the arrow a direction). The outer peripheral cylindrical portion 40d is a cylindrical shape centering on the axis x extending from the outer peripheral end (arrow a direction) end of the central annular portion 40c along the axis x toward the housing side (arrow c direction). Part.

  The outer peripheral side annular portion 40e is an annular portion centering on the axis line x extending from the end of the outer peripheral side cylindrical portion 40d on the housing side (arrow c direction) to the outer peripheral side (arrow a direction). A canceller lip 41 is integrally fixed to an end portion on the outer peripheral side (arrow a direction) of the outer peripheral ring portion 40e.

  The canceller lip 41 projects from the outer peripheral side (arrow a direction) end of the outer peripheral ring portion 40e of the canceller seal 40 to the housing side (arrow c direction) and the outer peripheral side (arrow a direction) along the axis x. It is the part formed so. The canceller lip 41 slides along the axis x on the inner peripheral side (arrow b direction) surface 10ha (hereinafter also referred to as "inner peripheral surface") of the outermost cylindrical portion 10h of the piston seal 10. A lip tip 41a that is in contact with the lip.

  A canceller hydraulic chamber P <b> 2 is formed between the canceller seal 40 and the piston seal 10. The canceller hydraulic chamber P2 is supplied with hydraulic oil through an oil hole 101c provided in the vicinity of the inner circumferential side annular portion 40a on the multi-plate clutch side (arrow d direction) on the inner circumferential surface 101a of the housing 101. The Thus, when the housing 101 rotates, centrifugal oil pressure is generated in the canceller hydraulic chamber P2, and the centrifugal oil pressure in the piston hydraulic chamber P1 is canceled.

  The snap ring 42 is a fixing member that supports and fixes the inner circumferential side annular portion 40 a of the canceller seal 40, and is fixed integrally with the housing 101 in a state of being fitted in the concave portion of the inner circumferential surface 101 a of the housing 101. ing.

  A return spring 30 is disposed between the innermost ring portion 10c of the piston seal 10 and the central ring portion 40c of the canceller seal 40 in a state of being evenly arranged. In practice, the end of the return spring 30 on the housing side (in the direction of the arrow c) is supported by a spring receiver 31 having an L-shaped cross section that is fixed to the inner peripheral surface of the innermost ring portion 10 c of the piston seal 10. The Further, the end of the return spring 30 on the multi-plate clutch side (in the direction of arrow d) is supported by the central annular portion 40 c of the canceller seal 40.

  The return spring 30 is an elastic member made of, for example, a metal compression coil spring, and urges the piston seal 10 toward the housing (in the direction of arrow c) so as to separate the piston seal 10 from the canceller seal 40. .

  In the above configuration, in the sealing device 1, the first range ar1 of the piston seal 10 in which the supply or discharge of oil to the piston hydraulic chamber P1 is advantageous due to the presence of the oil hole 101b formed in the housing 101 is defined. Then, the covering portion 23 is covered with a covering thickness t1 that is thinner than the reference thickness.

  Further, in the sealing device 1, the piston seal 10 is defined such that the supply or discharge of oil to the piston hydraulic chamber P1 is more disadvantageous than the first range ar1 due to the absence of the oil hole 101b formed in the housing 101. In the second range ar2, the covering portion 23 is covered with a covering thickness t2 that is thicker than the reference thickness.

  As described above, in the sealing device 1, the first range ar1 of the piston seal 10 in which the supply or discharge of the oil to the piston hydraulic chamber P1 is advantageous due to the presence of the oil hole 101b formed in the housing 101, and It is possible to form an entirely non-uniform covering portion 23 with covering thicknesses t1 and t2 corresponding to the second range ar2 defined as disadvantageous.

  In the sealing device 1, since the covering portion 23 is covered with a covering thickness t 1 that is thinner than the reference thickness in the first range ar 1 of the piston seal 10, the inner peripheral surface 101 a of the housing 101 is opposed to the oil hole of the piston seal 10. A gap in the stroke direction (arrow cd direction) with the area ar1 becomes wide. Thereby, since the operation | movement of the piston seal 10 becomes insensitive to supply or discharge | emission of hydraulic fluid by the part, the sealing device 1 can relieve the hypersensitive tendency of the stroke behavior of the piston seal 10.

  Further, in the sealing device 1, since the covering portion 23 is covered with the covering thickness t <b> 2 that is thicker than the reference thickness in the second range ar <b> 2 of the piston seal 10, the oil is applied to the inner peripheral surface 101 a of the housing 101 and the oil of the piston seal 10. The gap in the stroke direction (arrow cd direction) with the hole facing area ar1 is narrowed. Thereby, since the operation of the piston seal 10 becomes more sensitive to the supply or discharge of the hydraulic oil, the sealing device 1 can alleviate the slow tendency of the stroke behavior of the piston seal 10.

  That is, in the sealing device 1, in the first range ar1 where the oil hole 101b of the housing 101 exists, the stroke behavior of the piston seal 10 is sensitive, so this is insensitive, and the second range ar2 where the oil hole 101b of the housing 101 does not exist. Then, since the stroke behavior of the piston seal 10 is slow, this can be made sensitive.

  As a result, the sealing device 1 can be operated in a stable state by preventing the piston seal 10 from being tilted and preventing the biasing of the stroke operation, so that the speed change at the time of clutch engagement with the multi-plate clutch 60 can be achieved. It is possible to prevent problems such as shock, abnormal noise, and rattling from occurring.

  As a result, the sealing device 1 allows the multi-plate clutch in a state where the piston seal 10 is smoothly and stably tilted along the axis x in accordance with the hydraulic pressure of the hydraulic oil supplied through the oil hole 101b of the housing 101. It moves to the side (arrow d direction), and the clutch press part 10i can fasten the multi-plate clutch 60 with the said piston seal 10. FIG.

  After that, when the hydraulic oil is discharged through the oil hole 101b of the housing 101, the sealing device 1 does not incline the piston seal 10 along the axis x in accordance with the supplied hydraulic pressure and keeps the housing in a smooth and stable state. It moves to the body side (arrow c direction), and the clutch pressing part 10 i can be separated from the multi-plate clutch 60 together with the piston seal 10.

<Second Embodiment>
As shown in FIG. 3, in the housing 101 of the sealing device 200 of the second embodiment, the oil hole 101b is located at a position closer to the outer peripheral side (in the direction of arrow a) than the oil hole 101b in the first embodiment. An oil hole 101f having a larger area is formed.

  In this case, the first range ar11 including the portion of the piston seal 10 facing the oil hole 101f of the housing 101 is thinner than the reference thickness and thinner than the thickness t1 of the first embodiment. The covering portion 23 is formed with a covering thickness of t1s.

  This is because the area of the oil hole 101f in the second embodiment is larger than the area of the oil hole 101b in the first embodiment, and therefore the stroke behavior of the piston seal 10 is more sensitive than in the first embodiment. Because. In the second range ar12 including other parts of the piston seal 10 excluding the first range ar11, a covering portion 23 is formed with a coating thickness of a thickness t2 larger than the reference thickness.

  Thus, in the sealing device 200 of the second embodiment, the first range ar11 of the piston seal 10 is covered with the covering portion 23 having the covering thickness t1s and t2 corresponding to the area of the oil hole 101f of the housing 101. Thus, stable stroke behavior can be realized without inclining the piston seal 10.

<Third Embodiment>
As shown in FIG. 4, the housing 101 of the sealing device 300 according to the third embodiment has a plurality of oil holes 101g formed at the inner peripheral side end portion of the left half of the housing 101 in the drawing, and a plurality of oil holes. A plurality of oil holes 101h having an area larger than that are formed on the outer peripheral side of the hole 101g.

  In this case, the left half in the drawing including the portion of the piston seal 10 facing the plurality of oil holes 101g, 101h in the housing 101 is defined as a first range ar21. Further, the right half in the drawing including the portion of the piston seal 10 that does not face the plurality of oil holes 101g, 101h is defined as a second range ar22.

  A covering portion 23 is formed in the first range ar21 of the piston seal 10 with a covering thickness of a thickness t1z smaller than the reference thickness. Further, in the second range ar22 including other portions of the piston seal 10 excluding the first range ar21, a covering portion 23 is formed with a coating thickness of a thickness t2 larger than the reference thickness.

  That is, the left half of the piston seal 10 in the drawing is defined as the first range ar21 in which the hydraulic oil is easily supplied or discharged because the oil hole has a large number of oil holes or the oil hole is dense. Compared with the range ar21, it is assumed that the second range ar22 is difficult to supply or discharge hydraulic oil because the oil hole is small or sparse.

  Thus, in the third embodiment, the piston seal 10 is formed by forming the covering portion 23 having the covering thicknesses t1z and t2 corresponding to the first range ar21 and the second range ar22 of the piston seal 10. Stable stroke behavior can be realized without tilting 10.

<Other embodiments>
In the first to third embodiments described above, the case where the canceller hydraulic chamber P2 is provided between the piston seal 10 and the canceller seal 40 has been described. However, the present invention is not limited to this. If the return spring 30 is disposed between the piston seal 10 and the canceller seal 40 and it is not necessary to consider the centrifugal hydraulic pressure, the canceller hydraulic chamber P2 is provided. You may make it the structure which does not have.

  The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the sealing device 1 according to the above-described embodiment, and all aspects included in the concept of the present invention and the claims. including. In addition, the respective configurations may be selectively combined as appropriate so as to achieve at least part of the above-described problems and effects. For example, the shape, material, arrangement, size, and the like of each component in the above embodiment can be changed as appropriate according to the specific usage mode of the present invention.

  The sealing device of the present invention is used for reducing the number of parts when moving the piston seal in a general-purpose machine such as a vehicle such as an automobile and its accessories, a general industrial machine, and a construction machine, thereby simplifying and downsizing. It is possible.

1,200,300 Sealing device 10 Piston seal 10a Inner circumferential side jaw portion 10b Innermost circumferential side cylindrical portion 10c Innermost circumferential side annular portion 10d Central cylindrical portion 10e Central annular portion 10f Outer circumferential side cylindrical portion 10g Outer circumferential side annular ring Portion 10h outermost cylindrical portion 10i clutch pressing portion (pressing portion)
DESCRIPTION OF SYMBOLS 11 Protrusion part 20 Elastic body part 21 Inner peripheral side seal lip 22 Outer peripheral side seal lip 23 Cover part 24 Convex part 30 Return spring 40 Canceller seal 41 Canceller lip 42 Snap ring 60 Multi-plate clutch (clutch member)
101 Housing 101a Inner peripheral surface 101b, 101c, 101f, 101g, 101h Oil hole P1 Piston hydraulic chamber P2 Canceller hydraulic chamber x axis

Claims (3)

Inside the housing, it is arranged so as to be able to reciprocate along the axis while facing the clutch member, and has a piston lip that seals and slides with an inner peripheral surface along the axis of the housing. An annular piston seal to be formed;
Fixed integrally to the outer peripheral side end of the pressing portion of the piston seal pressed or separated from the clutch member in accordance with the oil pressure of oil supplied to the piston hydraulic chamber from an oil hole formed in the housing, A protrusion that prevents relative rotation of the piston seal with respect to the housing by engaging with an engagement recess formed in the peripheral surface;
A covering portion made of an elastic material that covers the outer peripheral surface of the piston seal facing the inner peripheral surface of the housing;
Of the outer peripheral surface of the piston seal, in the first range in which the oil supply or discharge to the piston hydraulic chamber is advantageous due to the presence of the oil hole in the housing, the covering portion has a reference thickness. A second coating that is coated with a predetermined coating thickness that is thinner than the first range, and is defined as being disadvantageous in supplying or discharging the oil to the piston hydraulic chamber from the first range of the outer peripheral surface of the piston seal. In a range, the covering portion is covered with a covering thickness larger than the reference thickness. The sealing device according to claim 1, wherein the covering portion is covered with the covering thickness corresponding to the area of the oil hole or the number of the oil holes. The said covering part coat | covered on the outer peripheral surface of the said piston seal becomes non-uniform | heterogenous as a whole by each said coating thickness according to the said 1st range and the said 2nd range. The sealing device as described.