JPH0545331U - Sealing device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a sealing device with improved sealing performance. [Structure] The housing 1 has an annular shape, and a cavity opening to the inner peripheral surface side is formed, and a pressure port 2 communicating with this is formed.
Have. The seal member 3 provided in the housing 2 has an outer lip portion 3a and an inner lip portion 3b, and has protrusions 4a and 4b.
It swings about. If a sealing device is provided in the outer cylinder 5, the outer casing 5 is divided into an outer side A and an inner side B, and the inner lip portion 3b, which is a sliding surface, slides on the shaft 6 to seal the two. Inside B
When the pressure becomes higher, the pressure is introduced into the pressure chamber 7 from the pressure port 2, and the outer lip portion 3a of the seal member 3 moves relative to the protrusions 4a and 4b in conjunction with the inner lip portion 3b. As a result, in the seal member 3, the inner lip portion 3b is positioned at an angle facing the internal pressure of the inner side B, and the inner lip portion 3b is prevented from being deformed by the action of pressure.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a sealing device, and more particularly to a sealing device which is disposed between two relatively movable members and seals one of the two members in a retractable state.

[0002]

[Prior art and its problems]

 Conventionally, by interposing a seal member between one member and the other member that is inserted into and retractable from the one member, the inner space of the one member is kept inside by this seal member. In a sealing device which is divided into the outside and thereby seals between the both, a so-called O-ring is generally used as a sealing member.

As is already known, the O-ring is an annular member made of an elastic material and having a circular cross section. For example, the outer periphery of the O-ring is the inner periphery of an outer cylinder. By arranging the O-rings between the members so that the inner surface and the outer peripheral surface of the shaft, which is the other member, come into contact with each other, the space inside the outer cylinder is sealed by the O-rings. It is divided into an inner side formed and an outer side communicating with the atmosphere, and a seal is provided between both members in a state in which the shaft is movable in the axial direction.

However, in the conventional sealing device using such an O-ring, the sealing property may be deteriorated when the condition inside the outer cylinder, which is one member, is severe.

That is, in the conventional sealing device, the outer peripheral portion of the O-ring which is the seal member is held by the inner peripheral surface of the housing which is one member, and the inner peripheral portion is the shaft which is the other member. It is slidably in contact with the outer peripheral surface of the shaft so that the shaft can be retracted from the O-ring. However, if the shaft retracts inward of the outer cylinder, the shaft will not move. As a result, the pressure inside the outer cylinder increases.

As described above, when the pressure inside the outer cylinder increases, the inner peripheral portion of the O-ring, which is in slidable contact with the outer cylinder, is deformed toward the outer side of the outer cylinder. There was a case where a gap was created between the shaft and the shaft to deteriorate the sealing property.

The present invention solves the above problems, and an object of the present invention is to provide a sealing device that can maintain the sealing property even when the internal pressure on the sealed side increases. ..

[0008]

[Means for solving problems]

 In order to solve the above-mentioned problems, the present invention, as a first invention, is arranged between two members that move relative to each other, so that one of the two members can be slid on the sliding surface. A sealing device that slides a member to seal between the two members, and has an opening that is formed on the sliding surface side and that has a pressure port that opens this opening to one end surface side. And a housing which is housed inside the housing and has an outer lip portion formed on the outer peripheral portion and an inner lip portion formed on the inner peripheral portion. Further, both end surfaces are in contact with the inner wall of the housing. A seal member having an annular protrusion formed thereon, and the pressure introduced / released from the pressure port acts on a portion on the non-sliding surface side of the protrusion, and the outer lip portion with the protrusion as a fulcrum. And the inner lip part simultaneously shake in the opposite direction. It is possible, and at this time, the sealing device is characterized in that the lip portion on the sliding surface side of the seal member moves in the direction opposite to the pressure acting direction with the protrusion as a fulcrum. It is a thing.

As a second invention including the first invention, the protrusions formed on both end surfaces of the seal member are formed at a portion closer to the sliding surface side than a central portion.

As a third invention including the first invention, the seal member has a structure in which a second-stage lip is formed at a portion on the end surface side of the lip portion on the sliding surface side.

[0011]

[Action]

 This invention adopts the above-mentioned means, and when a pressure acts on the sealing device and a pressure is introduced or released from the pressure port, the action of the pressure causes an inner lip portion and an outer portion of the seal member. The lip moves in conjunction with each other, moving relative to the protrusion as a fulcrum, which causes the lip on the sliding surface side of the seal member to move in the direction opposite to the direction in which pressure is applied. It will be.

Then, the lip portion on the sliding surface side of the seal member comes to be positioned inside the housing at an angle so as to oppose the pressure acting on the lip portion. Deformation due to the pressure of the moving surface side lip is prevented.

Further, when the acting pressure is large, the second-stage seal comes into further contact with the mating member, so that the sealing property can be improved.

[0014]

【Example】

 Embodiments of the present invention shown in the drawings will be described below. FIG. 1 is a diagram showing an embodiment of the present invention. That is, in the sealing device shown in FIG. 1, a pressure is applied between the outer cylinder 5 which is one member and the shaft 6 which is the other member which is inserted in the outer cylinder 5 in a state of being movable in the axial direction. An annular housing 1 having a force port 2 and having a cavity open to the inner peripheral surface side is arranged, and an annular cavity having protrusions 4a and 4b is provided in the interior cavity of the housing 1. The seal member 3 is disposed, and at this time, the inner lip portion 3b of the seal member 3 is in contact with the shaft 6, and the outer lip portion 3a is in contact with the side surface 1a forming the inner space of the housing 1, respectively. It is a thing.

When pressure is introduced from the pressure port 2 of the housing 1, the pressure causes the seal member 3 in the housing 1 to contact the outer lip portion 3a with the protrusions 4a and 4b as fulcrums. The inner lip portion 3b and the inner lip portion 3b are moved relative to each other in the axial direction to swing.

In FIG. 1, an outer cylinder 5 which is one member supports a shaft 6 which is the other member by being inserted therein in a state of being movable in the axial direction. Since the seal device is disposed between the shaft 6 and the shaft 6, the inner space of the outer cylinder 5 is divided into an outer side A and an inner side B by the seal device.

At this time, the outer side A of the inner space of the outer cylinder 5 is in communication with the atmosphere and atmospheric pressure is acting, while the inner side B of the inner space of the outer cylinder 5 is sealed by a sealing device. A vacant space is formed.

The seal device arranged between the outer cylinder 5 and the shaft 6 is composed of a housing 1 and a seal member 3.

The housing 1 is formed in an annular shape, and has a cavity formed in the inner peripheral surface thereof. The pressure port 2 is formed on one end surface of the housing 1 and the port 8 is formed on the other end surface thereof. Are formed so as to open respectively, so that the internal cavity communicates with the outside through the pressure port 2 and the port 8.

A seal member 3 is arranged in the inner space of the housing 1. The seal member 3 has an annular shape in which an outer lip portion 3a is formed on the outer peripheral portion and an inner lip portion 3b is formed on the inner peripheral portion. The annular protrusions 4a and 4b are formed on the other side.

The inner lip portion 3b of the seal member 3 has a pointed portion formed by inwardly projecting the central portion of the inner peripheral surface of the seal member 3 and located on both end surface sides of the pointed portion. A second stage lip 3c is formed on the portion.

The seal member 3 has a projection 4 a formed on one end surface thereof which abuts on the inner wall of the housing 1 on the side where the pressure port 2 is open, and a projection 4 b formed on the other end surface. Is disposed in the housing 1 in a state of abutting against the inner wall of the housing 1 on the side where the port 8 is opened, whereby the outer lip portion 3a and the inner lip portion 3b of the seal member 3 are projected. The seal member 3 is movable relative to each other in the axial direction with the fulcrums 4a and 4b as fulcrums, so that the entire seal member 3 can swing in an inner space of the housing 1.

At this time, the seal member 3 is in a state in which the outer lip portion 3 a is in contact with the inner side surface 1 a of the housing 1 and the inner lip portion 3 b is protruded inward from the inner peripheral surface of the housing 1. Leave.

When the seal member 3 is arranged in the housing 1, the pressure in the inner space of the housing 1 surrounded by the surface of the seal member 3 extending from the protrusion 4 a to the outer lip portion 3 a and the inner wall of the housing 1 is increased. A chamber 7 is formed, and a pressure adjusting chamber 9 is formed which is surrounded by the surface of the seal member 3 extending from the protrusion 4b to the outer lip portion 3a and the inner wall of the housing 1. At this time, the pressure chamber 7 is a pressure port. 2 and the pressure adjusting chamber 9 is connected to the port 8, respectively.

The sealing device configured as described above is arranged inside the outer cylinder 5 with its axis aligned with the axis of the outer cylinder 5, and then the housing 1 and the seal member 3 By inserting the shaft 6 inside the inner peripheral portion, the sealing device is interposed between the outer cylinder 5 and the shaft 6.

At this time, a sealing device is arranged so that the pressure port 2 of the housing 1 is opened inside B of the outer cylinder 5 and the port 8 is opened outside A of the outer cylinder 5, respectively. The pressure chamber 7 communicates with the inner space B of the outer cylinder 5 through the pressure port 2, and the pressure adjusting chamber 9 communicates with the outer space A of the outer cylinder 5 through the port 8. ..

An O-ring 10 is interposed between the housing 1 and the outer cylinder 5 to seal the two.

Next, the operation of the above will be described. As described above, this sealing device is provided between the outer cylinder 5 and the shaft 6 which is the other member so as to partition the outside A and the inside B inside the outer cylinder 5 which is one member. By interposing it, the shaft 6 is sealed between the outer cylinder 5 and the shaft 6 in a state where the shaft 6 can be retracted from the sealing device.

That is, when the seal device is arranged between the outer cylinder 5 and the shaft 6, the pointed portion of the inner lip portion 3 b of the seal member 3 comes into slidable contact with the outer peripheral surface of the shaft 6. Further, the outer lip portion 3a comes into contact with the side surface 1a of the inner wall of the housing 1 to seal the gap between the housing 1 and the shaft 6 with the seal member 3, and further, to connect the housing 1 and the outer cylinder 5 to each other. Since the O-ring 10 is interposed between the two, the O-ring 10 seals the space between them, and as a result, the shaft 6 and the outer cylinder 5 are sealed by the sealing device, and the inside B of the outer cylinder 5 is sealed. The vacant space is sealed.

Even if the shaft 6 moves in the axial direction and moves in and out of the sealing device, the inner lip portion 3 b of the seal member 3 slides along the outer peripheral surface of the shaft 6, thereby The sealability between 6 and the seal member 3 is ensured.

Here, in FIG. 1, the angle formed between the inner peripheral surface of the inner lip portion 3b of the seal member 3 on the side of the protrusion 4a and the outer peripheral surface of the shaft 6 is α, and the inner angle of the inner lip portion 3b on the side of the protrusion 4b is α. Assuming that the angle formed by the peripheral surface and the outer peripheral surface of the shaft 6 is β, the seal member 3 is normally positioned in the housing 1 so that α = β, and the center of the outer lip portion 3a of the seal member 3 is The portion and the pointed portion of the inner lip portion 3b are located on the lines in the direction orthogonal to the axis.

When the shaft 6 is retracted in the direction of the inner side B of the outer cylinder 5 from the sealing device, the inner pressure of the inner side B of the outer cylinder 5 increases as the shaft 6 is retracted. The sealing performance of the sealing device does not deteriorate.

That is, when the internal pressure of the inner side B of the outer cylinder 5 increases, this pressure is introduced into the pressure chamber 7 from the pressure port 2 of the housing 1 and acts on the portion of the seal member 3 outside the protrusion 4 a. Come to do. At this time, since the protrusion 4a of the seal member 3 is formed inward of the central portion of the end face, the area of the end face of the portion outside the protrusion 4a is larger than the area of the inner portion, Therefore, due to the pressure introduced from the pressure port 2, a greater force is exerted on the outer portion than on the protrusion 4a of the seal member 3 than on the inner portion.

Then, the seal member 3 moves relative to the protrusion 4a and the inner lip portion 3b relative to the protrusion 4a and the protrusion 4a, respectively, with the protrusions 4a and 4b contacting the housing 1 as fulcrums. Accordingly, the angle α on the protrusion 4a side of the inner lip portion 3b becomes larger than the angle β on the protrusion 4b side (α> β), and the seal member 3 becomes the outer lip portion 3a and the inner lip portion. Among the angles formed by the straight line connected to 3b and the axis of the shaft 6, the protrusion 4b is positioned at an acute angle.

As described above, the seal member 3 is positioned such that the angle formed by the inner lip portion 3 b and the shaft 6 is α> β, so that the inner peripheral surface of the housing 1 and the shaft 6 are separated from each other. The internal pressure of the inner side B of the outer cylinder 5 that acts from the gap increases the component force in the direction of the straight line connecting the outer lip portion 3a and the inner lip portion 3b at the tip of the seal member 3, Since the component force in the direction becomes small, the inner lip portion 3b is prevented from being deformed in the direction of the outer side A by the inner pressure force of the inner side B of the outer cylinder 5, and thereby the space between the seal member 3 and the shaft 6 is prevented. Sealing property is ensured.

When the shaft 6 is further retracted from the sealing device and the internal pressure of the inner side B of the outer cylinder 5 is further increased, the relative movement between the outer lip portion 3a and the inner lip portion 3b of the seal member 3 causes , The second-stage lip 3c formed on the protrusion 4b side of the inner lip portion 3b comes into contact with the outer peripheral surface of the shaft 6, and the inner-lip portion 3b is doubled by its pointed portion and the second-stage lip 3c. It comes to act as a seal and further improves the sealing performance.

Further, as the outer lip portion 3 a of the seal member 3 moves, the volume inside the pressure adjusting chamber 9 formed inside the housing 1 changes, but the pressure adjusting chamber 9 has an outer cylinder 5 a. Since the port 8 communicating with the outer side A of the above is made conductive, the pressure adjusting chamber 9 is always maintained at the atmospheric pressure, which allows the operation of the seal member 3 in the housing 1 to be smooth. You can do it.

When the shaft 6 protrudes from the sealing device and the pressure inside the outer cylinder 5 decreases, the pressure in the pressure chamber 7 in the housing 1 is released from the pressure port 2. Therefore, the outer lip portion 3a of the seal member 3 is relatively moved to the protrusion 4a side, and the inner lip portion 3b is relatively moved to the protrusion 4b side, so that the angle α with the shaft 6 on the protrusion 4a side of the inner lip portion 3b is changed. The angle becomes smaller than the angle β with the shaft 6 on the side of the protrusion 4b (α <β), and the inner lip portion 3b is prevented from being deformed in the direction of the inner side B of the outer cylinder 5. Similarly, the sealing property is ensured.

In the above embodiment, the inner lip portion 3b of the seal member 3 is used as the sliding surface. However, when the outer lip portion 3a is used as the sliding surface, the housing 1 has its outer periphery. The internal cavity is formed so as to open to the surface side, and the projections 4a and 4b of the seal member 3 are formed on the outer surface of the end face and the second lip is formed on the outer lip portion 3a. Further, the pressure chamber 7 is formed by the surface extending from the protrusion 4a to the inner lip portion 3 and the inner wall of the housing 1, and when the shaft 6 moves in the axial direction, the outer lip portion 3a of the seal member 3 moves to the outside. It may slide along the inner peripheral surface of the cylinder 5 so that the seal device moves integrally with the shaft 6.

At this time, when the pressure on the inner side B of the outer cylinder 5 increases as the shaft 6 moves, the pressure is guided to the pressure chamber 7 from the pressure port 2 and acts on the inner lip portion 3 b of the seal member 3. As a result, the outer lip 3a of the seal member 3 interlocks with the inner lip 3b and swings around the protrusions 4a and 4b as a fulcrum, and the outer lip which is the lip on the sliding surface side. 3a moves toward the protrusion 4a side while facing the internal pressure of the inner side B of the outer cylinder 5.

In the above embodiment, the protrusions 4a and 4b, which serve as fulcrums for swinging the seal member 3, were formed on the seal member 3, but instead, the protrusions 4a and 4b on the housing 1 are the same. You may make it form the protrusion which acts.

[0042]

[Effect of the device]

 As described above, according to the present invention, the sealing member swings in response to the internal pressure inside the outer cylinder, which is one member sealed by the sealing device, to move the lip portion on the sliding surface side. The seal member is positioned inside the housing at an angle that opposes the pressure acting on the lip on the sliding surface, so that even if the internal pressure inside the outer cylinder changes, that pressure will change. It is possible to prevent the deformation due to the action of, and to prevent a gap from being formed between the lip portion on the sliding surface side of the seal member and the mating member, thereby improving the sealing performance. There is an effect of becoming.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

[Explanation of symbols]

 1 ... Housing 1a ... Side surface 2 ... Pressure port 3 ... Seal member 3a ... Outer lip portion 3b ... Inner lip portion 3c ... Second stage lip 4a, 4b ... Protrusion 5 ... Outer cylinder 6 ... … Axis 7 …… Pressure chamber 8 …… Port 9 …… Pressure adjusting chamber 10 …… O-ring

Claims (3)

[Scope of utility model registration request] 1. A seal device, which is disposed between two members that move relative to each other so that one of the two members slides on a sliding surface to seal the two members. An annular housing (1) having a pressure port (2) that opens to the sliding surface side and opens this space to one end surface side, and is housed inside the housing (1) , An outer lip portion (3a) is formed on the outer peripheral portion, and an inner lip portion (3b) is formed on the inner peripheral portion. Further, both end surfaces have an annular shape that contacts the inner wall of the housing (1). And a seal member (3) having protrusions (4a, 4b) formed thereon, and the pressure introduced / released from the pressure port (2) acts on a portion on the non-sliding surface side of the protrusion (4a). Then, using the protrusions (4a, 4b) as fulcrums, the outer lip portion (3a ) And the inner lip portion (3b) can be simultaneously swung in opposite directions, and at this time, the lip portion on the sliding surface side of the seal member (3) has the protrusions (4a, 4b).
A sealing device characterized in that it moves in a direction opposite to the acting direction of pressure with b) as a fulcrum. 2. The sealing device according to claim 1, wherein the protrusions (4a, 4b) formed on both end surfaces of the seal member (3) are formed at a portion closer to a sliding surface side than a central portion. 3. The seal device according to claim 1, wherein the seal member (3) has a second-stage lip (3c) formed at a portion on the end surface side of the sliding surface side lip portion.