JP2000329235A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device capable of preventing the deterioration of performance caused by the effect of foreign matter and improving the sealing property and high reliability by providing a sub-lip invariably contiguous to the end face of a piston insertion hole on a seal lip. SOLUTION: An outer peripheral seal lip 8 extends to the radial section 32A side of an axial second annular recess 32 and is inclined to open radially outward, and a lip tip is slidably sealed and brought into contact with the outer periphery of a piston insertion hole 5. The outer peripheral seal lip 8 is provided with a contaminant catcher 9 as a sub-lip. The contaminant catcher 9 extends in the axial direction from the vicinity of the lip tip of the outer peripheral seal lip 8, invariably abuts on the radial section 32A at the end face of the piston insertion hole 5 at the lip tip through a nearly R-shaped cross section, and prevents contaminants from intruding into the outer peripheral lip 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device used for a piston portion or the like for switching a clutch of a shift switching device of an automatic transmission for an automobile or the like.

[0002]

2. Description of the Related Art A conventional sealing device of this type is, for example, an annular piston member related to a shift switching input in an automatic transmission (A / T, CVT, T / F) of an automobile. There is a piston member having seal lips on the inner and outer circumferences of a piston member having a function of receiving and transmitting an input to a clutch.

FIG. 4 is a sectional view of a main part of an automatic transmission using such a conventional sealing device.

In FIG. 1, reference numeral 100 denotes a holding ring having a substantially U-shaped cross section attached to a sleeve 101 mounted on a shaft (not shown). The substantially U-shaped cross section of the holding ring 100 has an annular piston insertion portion. A hole 102 is formed. That is, the retaining ring 100 forms a housing having an annular piston insertion hole 102.

An annular piston member 103 having a substantially U-shaped cross section is slidably disposed in the piston insertion hole 102, and a multi-plate clutch 104 is provided on the outer peripheral side of the lower part of the piston member 103 in the drawing. It is provided.

A cancel plate 105 is provided between the piston member 103 and the multi-plate clutch 104. The cancel plate 105 is mounted on the inner peripheral side of the piston insertion hole 102. The movement of the cancel plate 105 in the axial direction is restricted by a stopper 106.

A seal lip 112 is provided on the outer periphery of the cancel plate 105 as a seal member. The seal lip 112 is in sealing contact with the inner peripheral surface of the cylindrical portion 103A on the outer peripheral side of the piston member 103.

Further, a leaf spring-like spring 107 is provided between the cancel plate 105 and the piston member 103 as an urging means, and the spring 107 moves the piston member 103 away from the cancel plate 105, that is, It is urged upward in the figure.

The piston member 103 has a piston insertion hole 10
The second closed surface 102 </ b> A comes into contact with the rubber-like elastic body 108 via a rubber-like elastic body 108 and stands still.

On the inner and outer circumferences of the piston member 103, there are provided seal lips 109A and 109B which slidably and slidably contact the inner and outer circumferential surfaces of the piston insertion hole 102.

In this way, the pressure chamber X and the oil chamber Y are separately formed in the piston insertion hole 102.

A cylindrical port on the inner peripheral side of the substantially U-shaped section of the holding ring 100 forming the piston insertion hole 102 has a pressure port 110 communicating with the outside and the pressure chamber X, and an oil chamber Y with the outside. And a port 111 communicating with the port.

In the above configuration, when the operating pressure PA acts on the pressure chamber X via the pressure port 110 of the holding ring 100 and the pressure rises, the piston member 103 moves the spring 10
7 moves downward in the axial direction against the urging force of 7, and pushes the multi-plate clutch 104 at the end of the cylindrical portion 103A of the piston member 103 to transmit power.

On the other hand, by supplying oil to the oil chamber Y via the port 111 of the retaining ring 100 and lowering the pressure in the pressure chamber X, the urging force of the spring 107
3 moves upward in the axial direction, the end of the cylindrical portion 103A of the piston member 103 is separated from the multi-plate clutch 104,
Cancel the transmission of power.

Thus, the multi-plate clutch 104 is turned on and off by reciprocating the piston member 103 in the axial direction.

[0016]

However, in the case of the above prior art, the automatic transmission (A / T) has
Foreign substances such as metal cutting powder, abrasion powder, and dust, which are structurally called contaminants, are removed by the centrifugal oil pressure to form the outer peripheral seal lip 109B.
The sliding portion of the outer peripheral seal lip 109B is scratched and abraded, resulting in a problem of reduced sealing performance.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and an object of the present invention is to improve the sealing performance, which can prevent a decrease in performance due to the influence of foreign matter. An object of the present invention is to provide a highly reliable sealing device.

[0018]

According to the present invention, there is provided a housing having a piston insertion hole, and a piston member slidably inserted into the piston insertion hole of the housing. A seal lip provided on the piston member and slidably and sealingly contacting the peripheral surface of the piston insertion hole, wherein the seal lip is always in contact with an end surface of the piston insertion hole. It is characterized by having.

According to this configuration, it is possible to prevent foreign matter from entering the sliding surface of the seal lip, and to prevent lip damage and wear.

Furthermore, since the occurrence of lip scratches and abrasion which cause oil leakage can be prevented, a decrease in performance due to the influence of foreign matter can be prevented, higher sealing performance can be ensured, and durability can be improved. Become.

The sub lip extends in the axial direction from the vicinity of the lip tip of the seal lip, contacts the end face of the piston insertion hole at the lip tip through a substantially R-shaped cross section, and operates the piston member. Accordingly, it is also preferable to bend and always contact the end face of the piston insertion hole.

Thus, even when the stroke of the piston member is short and there is no space for providing a dust lip on the same sliding surface as the seal lip, it is possible to prevent foreign matter from entering the sliding surface of the seal lip. , Higher sealing performance can be secured.

[0023] The sub lip has a slit for dividing the pressure chamber surrounded by the piston insertion hole, the piston member and the seal lip into two, and connecting one and the other of the two divided pressure chambers. Are also suitable.

Thus, lubrication of the lip portion of the seal lip can be ensured, and high sealing performance can be obtained.

[0025]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The material, the shape, and the relative arrangement thereof should be appropriately changed depending on the configuration of the apparatus to which the invention is applied and various conditions, and are not intended to limit the scope of the invention to the following embodiments.

FIG. 1 shows a sealing device according to an embodiment of the present invention.
And FIG. As shown in FIG. 2, the sealing device 1 according to the present embodiment has an automatic transmission (A / A /
T, CVT, T / F).

That is, the sealing device 1 is a ring-shaped piston member generally related to the input of gear shifting switching in an automatic transmission. The sealing device 1 mainly seals the inner and outer circumferences of the piston member having a function of receiving hydraulic pressure and transmitting input to a clutch. It has a lip.

In the drawing, reference numeral 2 denotes a sleeve, and the sleeve 2 is mounted on a rotating shaft (not shown). On the outer peripheral side of the sleeve 2, a holding ring 3 forming a housing is provided.

The retaining ring 3 has a substantially S-shaped cross section and includes a first annular concave portion 31 that opens outward in the axial direction (upper side in the figure) and a second annular concave portion 32 that opens inward (lower side in the figure) in the axial direction. The axially outer end of the inner peripheral cylindrical portion 31B of the first annular concave portion 31 is attached to the sleeve 2 with the stopper 14 restricting the axial movement thereof.

The second annular concave portion 32 comprises a radial portion 32A, an outer cylindrical portion 32B, and an inner cylindrical portion 32C (an outer cylindrical portion of the first annular concave portion 31). Extends inward in the axial direction from the radial portion 31A of the first annular concave portion 31.

The outer peripheral side cylindrical portion 32B is stepped, and the inner side in the axial direction is located on the outer peripheral side and has a large diameter. Furthermore, the inner peripheral side cylindrical portion 32C is also stepped, and the first annular concave portion 31 is located closer to the radial portion 31A on the inner peripheral side and has a smaller diameter.

The boundary between the large-diameter portion 321B and the small-diameter portion 322B on the inner side in the axial direction of the outer cylindrical portion 32B is closer to the outside in the axial direction than the small-diameter portion 321C of the inner cylindrical portion 32C. 321B is the small-diameter portion 32 on the outside in the axial direction.
It is longer than 2B. This longer large diameter part 3
The multi-plate clutch 4 is housed on the inner peripheral side of 21B.

On the other hand, the outer cylindrical portion 3 of the second annular concave portion 32
On the small-diameter portion 322B side of 2B, an annular piston insertion hole 5 is formed by the small-diameter portion 322B, the radial portion 32A, and the large-diameter portion 322C of the inner cylindrical portion 32C.

An annular piston member 6 is slidably inserted in the annular piston insertion hole 5 in the axial direction.

The piston member 6 is a metal ring having a substantially U-shaped cross section. The washer-shaped end wall 61 facing the end face of the radial portion 32A of the second annular concave portion 32 of the holding ring 3, and the inner and outer diameters of the end wall 61. And a pair of inner and outer skirt portions 62 and 63 extending axially toward the multiple disc clutch 4 from the ends. The outer peripheral side of the end wall 61 (the outer peripheral skirt 63 side)
The shift is shifted toward the multiple disc clutch 4 side.

Then, at the tip of the inner peripheral skirt portion 62,
An inward flange portion 62A slightly extending inward in the radial direction is provided, and an inner peripheral seal lip 7 made of a rubber-like elastic material is integrally baked and fixed to the inner diameter end of the inward flange portion 62A.

The inner peripheral seal lip 7 extends toward the radial portion 32A of the second annular concave portion 32 in the axial direction and is inclined so as to open inward in the radial direction. Outer peripheral surface (large diameter portion 322 of inner cylindrical portion 32C)
(Outer peripheral surface of C) in slidable sealing contact.

Further, an outer peripheral seal lip 8 made of a rubber-like elastic material is integrally baked and fixed to a corner between the outer peripheral skirt portion 63 and the end wall 61.

The outer peripheral seal lip 8 extends toward the radial portion 32A of the second annular concave portion 32 in the axial direction and is inclined so as to open outward in the radial direction. Surface (small diameter portion 322 of outer cylindrical portion 32B)
B (inner peripheral surface of B) in slidable sealing contact.

The outer seal lip 8 (seal lip) has a contamination catcher 9 as a sub lip.
Is provided. The contamination catcher 9 extends in the axial direction from near the lip tip of the outer peripheral seal lip 8,
After passing through the substantially R-shaped section, the distal end of the lip is always in contact with the radial portion 32A as the end face of the piston insertion hole 5, thereby preventing contamination from entering the outer peripheral seal lip 8.

In this manner, the piston member 6 and the holding ring 3 are interposed via the inner seal lip 7 and the outer seal lip 8.
A pressure chamber A is formed between the second annular concave portion 32 and the radial portion 32A side of the second annular concave portion 32.

Further, on the sliding surfaces of the inner peripheral seal lip 7 and the outer peripheral seal lip 8, parallel grooves as parallel grooves or parallel protrusions as parallel protrusions are provided on the circumference as irregularities.

The inner and outer peripheral seal lips 7, 8 may be formed by molding or by cutting with a knife.

Further, the end surface of the end wall 61, the inner peripheral surface of the inner peripheral skirt portion 62, and the outer peripheral surface of the outer peripheral skirt portion 63 are coated with the end surfaces, inner peripheral and outer peripheral covering portions 10, 11, and
12, the inner peripheral seal lip 7, the outer peripheral seal lip 8, and the contamination catcher 9.
Is integrally formed with the end face, the inner and outer peripheral coating portions 10, 11, and 12.

The end surface covering portion 10 is provided with a convex portion 10A for positioning the piston member 6 by contacting the end surface of the radial portion 32A of the second annular concave portion 32, which is the deep end surface of the piston insertion hole 5. ing.

A cancel plate 13 is provided on the side of the multi-plate clutch 4 of the second annular concave portion 32 opposite to the piston member 6 as an annular regulating member for regulating the axial movement. The cancel plate 13 is a metal ring made of a thin steel plate, and is set to have an inner diameter that is detachable from the small-diameter portion 321C of the inner peripheral cylindrical portion 32C of the second annular concave portion 32. Has a piston member 6
The movement in the direction away from is regulated.

The outer diameter of the cancel plate 13 is smaller than the inner diameter of the outer peripheral skirt 63 of the piston member 6.

That is, the cancel plate 13 is a metal ring extending from the small-diameter portion 321C of the inner peripheral cylindrical portion 32C of the second radial concave portion 32 to the outer peripheral skirt portion 63 of the piston member 6. It has a cylindrical portion 13A, an inward flange portion 13B extending from the end of the cylindrical portion 13A on the side of the multi-plate clutch 4 toward the small-diameter portion 321C, and an outer skirt portion 6 from the end of the piston member 6 on the side.
3 has an outwardly extending flange portion 13C extending toward the third side.
An oil seal 15 as a seal member slidably and sealingly contacting the inner peripheral surface of is provided.

In this manner, the cancel plate 13
An oil chamber B is formed between the oil chamber C and the piston member 6 and is separated from an oil chamber C on the multi-plate clutch 4 side.

The large-diameter portion 322C of the inner peripheral cylindrical portion 32C of the second annular recess 32 of the holding ring 3 has a passage 16 communicating with the pressure chamber A, and the small-diameter portion 321C has a passage communicating with the oil chamber B. 17 are provided.

A spring 18 is provided between the cancel plate 13 and the piston member 6 as urging means for urging the piston member 6 away from the cancel plate 13, that is, upward in FIG.

The spring 18 is a leaf spring and has a cylindrical portion 18A slightly inclined outward in the radial direction, and a cylindrical portion 1A.
8A, an outward flange portion 1 extending radially outward from an end of the piston member 6 on the side of the piston member 6 and inclined toward the end wall 61 of the piston member 6
8B and an inward flange portion 18C extending radially inward from the end of the cancel plate 13 side.

The end surface of the inward flange portion 18C abuts against the end surface of the inward flange portion 13B of the cancel plate 13, and the inclined outer diameter end portion of the outward flange portion 18B contacts the end wall 61 of the piston member 6. In contact therewith, the piston member 6 is urged away from the cancel plate 13. The port portion 20 of the mating housing 19, which is the mating mounting portion that forms the mounting space D of the automobile or the like in which the sealing device 1 is mounted in the first annular concave portion 31 of the holding ring 3, is inserted in a fluid-tight manner. is there.

The port portion 20 has the outside and the first annular recess 3.
1 has a port 20A that communicates with the inside, but its open end is closed by a sphere 20B. This port 20A
Has a communication passage 20C communicating with the passage 16 of the holding ring 3, so that the working pressure PA is supplied to the pressure chamber A from outside.

In the above configuration, since the piston member 6 and the cancel plate 13 are attached to the sleeve 2 via the holding ring 3, the piston member 6 and the cancel plate 13 rotate together with the unit by the rotation of the rotating shaft on which the sleeve 2 is mounted. (0
About 8000 rpm).

When the oil is supplied to the oil chamber B through the passage 17 of the holding ring 3 and the pressure in the pressure chamber A becomes low, the urging force of the spring 18 is applied to the piston member 6, and the end face is covered. The convex portion 10A of the portion 10 is the second annular concave portion 3 of the holding ring 3.
2 and is stationary in contact with the radial portion 32A.

The operating pressure PA acts on the pressure chamber A via the port 20A of the port portion 20 of the mating housing 19, the communication passage 20C and the passage 16 of the holding ring 3 (5 to 30k).
gf / cm ² ), when the pressure increases, the piston member 6 moves downward in FIG. 2 against the urging force of the spring 18, and a multi-plate clutch is formed at the end of the outer peripheral skirt portion 63 of the piston member 6. Press 4 to transmit power.

When the transmission of power is released, the oil is supplied to the oil chamber B and the pressure in the pressure chamber A is reduced as described above, whereby the urging force of the spring 18 causes the piston member 6 to move. Move it up and down. Thereby, it returns to the original position.

In the sealing device having the above configuration, the provision of the contamination catcher 9 allows the automatic transmission (A /
T) During operation, it is possible to prevent contamination that moves to the pressure chamber A due to centrifugal oil pressure caused by rotation of the rotating shaft on which the sleeve 2 is mounted from entering the sliding surface of the outer peripheral seal lip 8, and oil leakage It is possible to prevent the occurrence of lip scratches and abrasion which cause the above.

As shown in FIG. 3, the contamination catcher 9 bends according to the movement of the piston member 6,
Even at the time of the upper limit and the lower limit of the stroke, the outer peripheral seal lip 8 is always in contact with the radial portion 32A of the retaining ring 3 to prevent contamination from entering the sliding surface of the outer peripheral seal lip 8.

Here, a normal dust lip may be used for the outer peripheral seal lip 8, but when the stroke of the piston is short, there is a problem that a space for providing the dust lip on the same sliding surface as the seal lip cannot be obtained. Yes, and
At the position where the contaminants accumulate due to the centrifugal oil pressure, the sliding will always occur while scraping the contaminated contaminants. Also, it does not slide while constantly scratching the accumulated contaminants and has excellent durability.

Further, the contamination catcher 9 has the circumference 2
It is also preferable to provide more than two oil passage holes or slits 21, whereby lubrication of the sliding surface of the outer peripheral seal lip 8 can be ensured. If the oil passage hole or the slit 21 is about two places on the circumference, the influence of contamination from therethrough is small, and higher sealing performance can be ensured as compared with the conventional shape.

Although the present embodiment has been described with reference to an example in which the piston portion is used in an automatic transmission such as an automobile,
You may use for the piston part of another mechanism.

[0064]

As described above, according to the present invention, the seal lip is provided with the sub lip which is always in contact with the inner peripheral end surface from the contact portion with the outer peripheral surface of the piston insertion hole. Foreign matter can be prevented from entering,
It is possible to prevent lip scratches and wear on the seal lip.

Furthermore, since the occurrence of lip scratches and abrasion, which cause oil leakage, can be prevented, deterioration in performance due to the influence of foreign matter can be prevented, higher sealing performance can be ensured, and reliability with improved durability can be ensured. It is possible to provide a high sealing device.

The sub-lip is bent in accordance with the operation of the piston member, so that the sub-lip is always in contact with the end face of the piston insertion hole. Therefore, the stroke of the piston member is short, and the dust lip is provided on the same sliding surface as the seal lip. Even when there is no space, foreign matter can be prevented from entering the sliding surface of the seal lip, and higher sealing performance can be ensured.

The slit connecting one and the other of the two pressure chambers can ensure lubrication of the lip portion of the seal lip, and can achieve high sealing performance.

[Brief description of the drawings]

FIG. 1 is a sectional view of a sealing device according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a piston portion of an automatic transmission to which the sealing device of the present invention is applied.

3A is a diagram showing a state at the time of a stroke upper limit, and FIG. 3B is a diagram showing a state at a time of a stroke lower limit.

FIG. 4 is a sectional view of a piston portion of an automatic transmission using a conventional sealing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing device 2 Sleeve 3 Retaining ring (housing) 31 First annular concave portion 31A Radial portion 31B Inner peripheral cylindrical portion 32 Second annular concave portion 32A Radial portion 32B Outer peripheral cylindrical portion 321B Large diameter portion 322B Small diameter portion 32C Inner periphery Side cylindrical part 321C Small diameter part 322C Large diameter part 4 Multi-plate clutch 5 Piston insertion hole 6 Piston member 61 End wall 62 Inner peripheral skirt part 62A Inward flange part 63 Outer peripheral skirt part 7 Inner peripheral seal lip 8 Outer peripheral seal lip (Seal lip) 9) Contamination catcher (sub lip) 10 End face covering portion 10A Convex portion 11 Inner peripheral covering portion 12 Outer peripheral covering portion 13 Cancel plate 13A Cylindrical portion 13B Inward flange portion 13C Outward flange portion 14, 14A Stopper 15 Oil seal 16, 17 Passage 18 Spring 18A Cylindrical part 8B outward flange portion 18C inward flange portion 19 mating housing 20 port section 20A port 20B spheres 20C communicating passage 21 slit

Claims (3)

[Claims] 1. A housing having a piston insertion hole, a piston member slidably inserted into the piston insertion hole of the housing, and a piston provided on the piston member and slidable on a peripheral surface of the piston insertion hole. And a sealing lip that comes into sealing contact with the sealing lip, wherein the sealing lip includes a sub lip that always contacts the end face of the piston insertion hole. 2. The sub lip extends in the axial direction from near the lip tip of the seal lip, contacts an end face of the piston insertion hole at the lip tip through a substantially R-shaped section, and The sealing device according to claim 1, wherein the sealing device always bends and contacts the end face of the piston insertion hole by bending according to an operation. 3. The sub lip divides a pressure chamber surrounded by the piston insertion hole, the piston member, and the seal lip into two, and has a slit connecting one and the other of the two divided pressure chambers. The sealing device according to claim 1, wherein the sealing device is provided.