JP2003329140A - Gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent protrusion phenomenon of a gasket 1 mounted on a mounting groove 4 provided in one member 2 of two members 2, 3 facing each other and tightly contacting with the other member 3 even if the size of the gap 6 between the two members 2, 3 changes under the influence of pressure, etc. <P>SOLUTION: An anti-protrusion projection 7 abutting on the inner surface of a mounting groove 4 for preventing a seal part 5 from protruding into the gap 6 between the two members 2, 3 is formed on a surface in a opposite direction of a pressure load in the seal part 5 tightly contacting with the two members 2, 3 and sealing a pressure fluid. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gasket which is a kind of sealing device.

[0002]

2. Description of the Related Art For example, in a device 51 shown in FIG.
A gasket 55 made of an O-ring or the like is interposed so that the pressure fluid flowing through the flow path 52 does not leak to the outside from between the one housing 53 and the other housing 54.

However, in this conventional gasket 55, when the high pressure P acts from the inner peripheral side as shown in the drawing to open a gap (not shown) between the pair of housings 53 and 54, the gasket is filled in this gap. A "stick-out phenomenon" occurs in which 55 sticks out.

The protrusion phenomenon widely occurs in various pressure devices and pressure systems, but as shown in FIG. 9, the protrusion phenomenon occurs once and the gasket 55 is formed in the gap 56.
When it protrudes, the gasket 55 will be
Because of the strong sandwiching between 3, 54, the gasket 55 may be damaged and the pressure fluid to be sealed may leak.

Further, in order to prevent the occurrence of the protrusion phenomenon, a technique of combining a gasket 55 and a backup ring 57 as shown in FIG. 10 has been developed.
If the size of the gap 56 fluctuates due to the influence of pressure or the like, the backup ring 57 is not a sufficient countermeasure. That is, for example, as shown on the left side of the figure, the size of the gap 56 at the initial stage of assembly is zero, and thereafter, due to the pressure load, the size of the gap 5 of about 0.5 mm as shown on the right side of the figure.
When 6 occurs, the backup ring 57 can be set only at the height at the initial stage of assembling, so even if the gap 56 further increases from there, no countermeasure can be taken.

[0006]

SUMMARY OF THE INVENTION In view of the above points, the present invention prevents the gasket from protruding even when the size of the gap between the two members varies due to the influence of pressure or the like. An object is to provide a gasket that can be effectively prevented.

[0007]

In order to achieve the above object, a gasket according to claim 1 of the present invention is mounted in a mounting groove provided in one of two members facing each other and is mounted in the other member. In the closely-contacting gasket, a surface of the seal portion that is in close contact with the two members and seals the pressure fluid on the side opposite to the pressure load direction is in contact with the inner surface of the mounting groove so that the seal portion has a gap between the two members. It is characterized in that a protrusion preventing protrusion for preventing the protrusion is provided.

According to a second aspect of the present invention, in the gasket according to the first aspect, the height dimension of the protrusion preventing protrusion is set smaller than the depth dimension of the mounting groove, and a gap between the two members is provided. Even in the closed state, a gap is formed between the protrusion preventing protrusion and the groove bottom surface of the mounting groove, and between the protrusion preventing protrusion and the other member.

A gasket according to claim 3 of the present invention is the gasket according to claim 1 or 2, wherein
A chamfer is provided on each of the peripheral edge of the mounting groove and the peripheral edge of the protrusion preventing protrusion, and an end of the chamfer provided on the protrusion preventing protrusion on the bottom surface side of the mounting groove is attached to the mounting groove when the gasket is mounted. It is characterized in that it is located closer to the bottom surface of the mounting groove than the end portion of the chamfer provided on the bottom surface side of the mounting groove.

Furthermore, the gasket according to claim 4 of the present invention is the gasket according to claim 1, 2 or 3 above, in which the seal portion of the gasket has a seal lip that is in close contact with the bottom surface of the mounting groove, and A seal lip that is in close contact with a member, and a pressure receiving groove is provided between the both seal lips.

In the gasket according to claim 1 of the present invention having the above-mentioned structure, since the protrusion preventing projection is integrally formed on the counter pressure side of the seal portion by the above structure, the protrusion preventing protrusion prevents the seal portion from moving. It functions as a spacer for blocking, and therefore even if the gasket is elastically deformed by the fluid pressure acting on the gasket, the seal portion, which is the gasket body, cannot reach the gap between the two members.

In addition to this, in the gasket according to claim 2 of the present invention having the above-mentioned configuration, the filling rate of the gasket in the state where the gap between the two members is closed is suppressed to a relatively small value by the above-mentioned configuration. In addition, it is possible to prevent the protrusion preventing protrusions from protruding and being caught in the gap between the two members in the process of closing the gap between the two members.

A third aspect of the present invention having the above structure.
In the gasket according to the above configuration, since the chamfered portion provided on the protrusion prevention protrusion is arranged at a position retracted from the gap between the two members with respect to the chamfered portion provided in the mounting groove, the gap between the two members is also closed. In the process, it is possible to prevent the protrusion prevention protrusion from protruding and being sandwiched in the gap between the two members.

Furthermore, in the gasket according to claim 4 of the present invention having the above structure, the seal portion is elastic so that the angle formed by the pair of seal lips is narrowed in the process of closing the gap between the two members by the above structure. Due to the deformation, the escape of the rubber due to the compression as seen in the compression type gasket such as the O-ring is unlikely to occur. Therefore, it is possible to prevent the protrusion prevention protrusion from being pushed into this clearance and entering the gap between the two members. In addition, since this lip shape has a self-sealing function, it has a good sealing property in a place where the pressure is high and the gap variation is large.

The present application includes the following technical matters.

That is, in order to achieve the above object, one gasket proposed by the present application is a gasket used in a place where the gap between the other member and the mating member largely changes due to high pressure, and the pressure side of the seal portion is It is characterized in that a protrusion having a square cross section is provided in the radial direction on the opposite side.

Further, the current problem is that when the groove gap of the housing is large and the load pressure is also large, the gasket sticks out into the groove gap and causes leakage. Therefore, we decided to provide a protrusion on the gasket cross section (on the side opposite to the pressure load direction) so that even if the protrusion occurs, it does not directly affect the sealing surface.

In this case, the cross-sectional shape of the gasket is considered by dividing it into a main seal portion and a protrusion portion. The height of the protrusion is
Take as much as possible in consideration of the movement of the gasket when protruding. By thus increasing the height of the protrusion, the contact area with the groove is increased, and even if the protrusion occurs, the movement of the gasket can be minimized.
In addition, the length of the protrusion should be long in order to reduce the influence on the sealing surface. By thus increasing the length of the projection, even if the gasket moves due to the protrusion, the movement of the sealing surface can be minimized because the distance to the sealing surface is long. As the rubber material, a high hardness material (Hs90 material) that is hard to stick out is used. The cross-sectional shape of the seal portion may be a round cross-section or a square cross-section, and it can be applied to a gasket having another irregular surface shape.

As described above, by providing the protrusion on the gasket cross section, even if the gasket is squeezed out, the influence of the squeezed out directly on the sealing surface can be reduced, and as a result, the life of the seal can be extended.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

First Embodiment FIG. 1 shows a half-cut cross section of a gasket 1 according to the first embodiment of the present invention, and its mounting state is shown in FIG.

The gasket 1 according to this embodiment is mounted in an annular mounting groove 4 provided in one of the pair of housings 2 and 3 facing each other and is in close contact with the other housing 3. And is configured as follows.

That is, first, the pair of housings 2,
An annular seal part 5 that is sandwiched between 3 and seals the pressure fluid
Is provided on the inner surface of the mounting groove 4 on the surface on the side opposite to the pressure load direction (fluid pressure P acts from the radially inner side) in the seal portion 5 which is the gasket main body portion, that is, on the outer diameter surface. A protrusion preventing projection 7 that is abutted against the seal portion 5 and prevents the seal portion 5 from protruding into the gap 6 between the pair of housings 2 and 3 is integrally formed radially outward.

The seal portion 5 is formed of a predetermined rubber-like elastic material into an annular body having a circular cross section, and the protrusion 7 is made of the same material as the seal portion 5 and has a predetermined height dimension H ₁ and length dimension L. It is formed as an annular body having a rectangular cross section.

The height dimension H ₁ of the protrusion 7 is set smaller than the height dimension H ₂ of the seal portion 5, and the mounting groove 4
Is set to be smaller than the depth dimension D. Further, the height dimension H ₂ of the seal portion 5 is set to be larger than the depth dimension D of the mounting groove 4, and the protrusion 7 is arranged at substantially the center of the seal portion 5 in the height direction. Therefore, when the gasket 1 is mounted as shown in FIG. 2, the protrusion 7 and the mounting groove 4 are
Between the groove bottom surface 4a and the protrusion 7 and the other housing 3
And gaps 8 and 9 in the height direction are formed between them and.
At this time, the gap side end portion 7b of the outer diameter surface 7a of the protrusion 7 is located closer to the groove bottom surface 4a (upper and lower sides in the figure) than the gap side end portion 4c of the side wall 4b of the mounting groove 4.

In the gasket 1 having the above-described structure, as described above, the protrusion preventing projection 7 is integrally formed on the outer diameter side of the seal portion 5 toward the outer side in the radial direction, and the protrusion 7 prevents movement of the seal portion 5. Since the gasket 1 functions as a spacer, the seal portion 5 reaches the gap 6 between the pair of housings 2 and 3 even when the gasket 1 is elastically deformed by the fluid pressure P acting on the gasket 1 from the inside in the radial direction. Never.
Therefore, it is possible to prevent the seal portion 5 from protruding into the gap 6 between the pair of housings 2 and 3 and being pinched and damaged.

In the mounted state of FIG. 2, gaps 8 and 9 are formed in the height direction between the protrusion 7 and the groove bottom surface 4a of the mounting groove 4 and between the protrusion 7 and the other housing 3, respectively. Therefore, the filling rate of the gasket 1 is set to be relatively small. Therefore, it is possible to prevent the protrusion 7 in place of the seal portion 5 from protruding into the gap 6 between the pair of housings 2 and 3 and being pinched and damaged.

Similarly, in the mounted state of FIG. 2, the gap side end 7b of the outer diameter surface 7a of the projection 7 is located closer to the groove bottom surface 4a than the gap side end 4c of the side wall 4b of the mounting groove 4. The former gap side end 7b is arranged at a position retracted from the gap 6 more than the latter gap side end 4c. Therefore, also from this point, it is possible to prevent the protrusion 7 from protruding into the gap 6 between the pair of housings 2 and 3 instead of the seal portion 5 and being pinched and damaged.

Second Embodiment FIG. 3 shows a half-cut cross section of a gasket 1 according to a second embodiment of the present invention, and the mounting state thereof is shown in FIGS. 4 and 5.

The gasket 1 according to this embodiment is mounted in an annular mounting groove 4 provided in one of the pair of housings 2 and 3 facing each other, and is in close contact with the other housing 3. And is configured as follows. In the pair of housings 2 and 3, when the fluid pressure P acting on them is increased, the gap 6 is opened as shown in FIG. 4, and when the fluid pressure is decreased, the gap 6 is closed as shown in FIG. is there.

That is, first, the pair of housings 2,
An annular seal part 5 that is sandwiched between 3 and seals the pressure fluid
Is provided on the inner surface of the mounting groove 4 on the surface on the side opposite to the pressure load direction (fluid pressure P acts from the radially inner side) in the seal portion 5 which is the gasket main body portion, that is, on the outer diameter surface. A protrusion preventing projection 7 that is abutted against the seal portion 5 and prevents the seal portion 5 from protruding into the gap 6 between the pair of housings 2 and 3 is integrally formed radially outward.

The seal portion 5 is formed of a predetermined rubber-like elastic material into an annular body. The seal portion 5 is in close contact with the groove bottom surface 4a of the mounting groove 4 and the other housing 3. The sealing lips 11 are integrally formed inward in the radial direction. Both seal lips 10, 11 are provided side by side in the axial direction, and an annular pressure receiving groove 12 is formed between both lips 10, 11.

The projection 7 is formed of the same material as the seal portion 5 as an annular body having a rectangular cross section having a predetermined height dimension H ₁ and length dimension L, and the outer diameter surface 7 of the projection 7 is formed.
a has chamfered portions 13 and 14 at both axial ends thereof, respectively.
Are formed. Although the chamfered portions 13 and 14 shown in the drawing are chamfers having an arcuate cross section (R shape), they may be chamfered with a straight cross section (cut shape) instead.

The height dimension H ₁ of the projection 7 is determined by the seal portion 5
Is smaller than the height dimension H _{2 of the} mounting groove 4 and smaller than the depth dimension D of the mounting groove 4. Further, the height dimension H ₂ of the seal portion 5 is set to be larger than the depth dimension D of the mounting groove 4, and the protrusion 7 is arranged at substantially the center of the seal portion 5 in the height direction. Therefore, when the gasket 1 is mounted as shown in FIG. 5, gaps 8 and 9 in the height direction are formed between the protrusion 7 and the groove bottom surface 4a of the mounting groove 4 and between the protrusion 7 and the other housing 3, respectively. The gaps 8 and 9 are formed so that the size thereof increases as the gap 6 between the pair of housings 2 and 3 expands as shown in FIG.

4 and 5, the groove bottom surface side end portion 14a of the gap side surface chamfer 14 provided on the outer diameter surface 7a of the projection 7 is the gap side end portion of the side wall 4b of the mounting groove 4. It is located on the groove bottom 4a side (upper and lower sides in the figure) than 4c.

In the gasket 1 having the above-described structure, the protrusion preventing projection 7 is integrally formed on the outer diameter side of the seal portion 5 toward the outer side in the radial direction as described above, and the protrusion 7 prevents movement of the seal portion 5. Since the gasket 1 functions as a spacer, the seal portion 5 reaches the gap 6 between the pair of housings 2 and 3 even when the gasket 1 is elastically deformed by the fluid pressure P acting on the gasket 1 from the inside in the radial direction. Never.
Therefore, it is possible to prevent the seal portion 5 from protruding into the gap 6 between the pair of housings 2 and 3 and being pinched and damaged.

Further, in the mounted state of FIGS. 4 and 5, between the protrusion 7 and the groove bottom surface 4a of the mounting groove 4 and the protrusion 7
Since the gaps 8 and 9 in the height direction are formed between the other housing 3 and the other housing 3, the filling rate of the gasket 1 is set to be relatively small. Therefore, it is possible to prevent the protrusion 7 in place of the seal portion 5 from protruding into the gap 6 between the pair of housings 2 and 3 and being pinched and damaged.

Similarly, in the mounted state of FIGS. 4 and 5, the clearance side chamfered portion 1 provided on the outer diameter surface 7a of the projection 7 is also provided.
Since the groove bottom surface side end portion 14a of No. 4 is located closer to the groove bottom surface 4a side than the gap side end portion 4c of the side wall 4b of the mounting groove 4, the former groove bottom surface side end portion 14a is the latter gap side end portion. It is arranged at a position retracted from the gap 6 more than 4c. Therefore, also from this point, it is possible to prevent the protrusion 7 from protruding into the gap 6 between the pair of housings 2 and 3 instead of the seal portion 5 and being pinched and damaged.

In addition, in the gasket 1 having the above structure, the seal portion 5 is elastic so that the angle formed by the pair of seal lips 10 and 11 is narrowed in the process of closing the gap 6 between the pair of housings 2 and 3. To transform
In the gasket 1, it is difficult for the rubber to escape due to compression as seen in a compression type gasket such as an O-ring. Therefore, it is possible to prevent the protrusion 7 from being pushed into this clearance and entering the gap 6 between the pair of housings 2 and 3, and from this point as well, the sealing portion 5 causes the gap 6 between the pair of housings 2 and 3. It can be prevented from protruding and being pinched and damaged.

The effect of preventing the protrusion due to the positional relationship of the chamfered portion 14 can be considered as follows when the chamfered portion 15 is also provided at the peripheral portion of the mounting groove 4 as shown in FIG. .

That is, as shown in FIG. 3A which is shown as a comparative example, when the gasket 1 is mounted, the protrusion 7
The groove bottom surface side end portion 14a of the gap side surface chamfered portion 14 provided on the outer diameter surface 7a of the groove 6 side is larger than the groove bottom surface side end portion 15a of the chamfered portion 15 provided at the peripheral portion of the mounting groove 4 (upper side in the drawing). ), The former groove bottom end 1
Since the groove 4a is arranged closer to the gap 6 than the latter groove bottom side end portion 15a, the protrusion 7 is likely to protrude into the gap 6 and be sandwiched in the process of closing the gap 6. On the other hand, as shown in FIG. 3B, conversely in the positional relationship, in the mounted state of the gasket 1, the groove bottom surface side end portion 14a of the clearance side chamfer 14 provided on the outer diameter surface 7a of the protrusion 7 is formed.
Is located closer to the groove bottom surface 4a (upper and lower sides in the figure) than the groove bottom surface side end 15a of the chamfered portion 15 provided on the peripheral edge of the mounting groove 4, the former groove bottom surface side end 14a is the latter groove. Since it is arranged at a position retracted from the gap 6 with respect to the bottom end portion 15a, the protrusion 7 does not easily stick out and get caught in the gap 6 during the process of closing the gap 6, so that the protrusion 7 sticks out to the gap 6. It can be prevented from being pinched and damaged.

In FIG. 6, the cross-sectional shape of the chamfered portions 14 and 15 is a circular arc shape (rounded shape), but as shown in FIG. 7, the cross-sectional shape of the chamfered portions 14 and 15 is a straight line shape ( The same applies to the case of (cut shape).

[0043]

The present invention has the following effects.

That is, in the gasket according to claim 1 of the present invention having the above structure, since the protrusion preventing protrusion functions as a spacer for preventing movement of the seal portion,
Even if fluid pressure acts on the gasket and the gasket is elastically deformed, the seal portion does not reach the gap between the two members. Therefore, it is possible to prevent the seal portion from protruding and being sandwiched between the two members and being damaged.

In addition to this, in the gasket according to claim 2 of the present invention having the above-mentioned structure, since the filling rate of the gasket in a state in which the gap between the two members is closed is relatively small, In the process of closing the gap between the members, the protrusion preventing protrusion can be prevented from protruding into the gap between the two members and being pinched and damaged.

A third aspect of the present invention having the above structure.
In the gasket according to, since the chamfered portion provided on the protrusion prevention protrusion is arranged at a position retracted from the gap between the two members with respect to the chamfered portion provided on the mounting groove, also in the process of closing the gap between the two members, It is possible to prevent the protrusion preventing projection from protruding and being caught in the gap between the two members and being damaged.

Furthermore, in the gasket according to claim 4 of the present invention having the above-mentioned structure, the seal portion is elastically deformed so that the angle formed by the pair of seal lips is narrowed in the process of closing the gap between the two members. Therefore, it is difficult for the rubber to escape due to the compression as seen in the compression type gasket such as the O-ring. Therefore, the protrusion preventing protrusion can be prevented from being pushed into the clearance and entering the gap between the two members, and thus the protrusion can be prevented from protruding into the gap between the two members and being pinched and damaged. .

[Brief description of drawings]

FIG. 1 is a half sectional view of a gasket according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a mounted state of the gasket.

FIG. 3 is a half sectional view of a gasket according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing a mounting state of the gasket.

FIG. 5 is a sectional view showing a state where the same gasket is mounted.

FIG. 6A is a sectional view of a main part showing a mounted state of a gasket according to a comparative example, and FIG. 6B is a sectional view of a main part showing a mounted state of a gasket according to an embodiment of the present invention.

7A is a cross-sectional view of a main part showing a mounted state of a gasket according to a comparative example, and FIG. 7B is a cross-sectional view of a main part showing a mounted state of a gasket according to an embodiment of the present invention.

FIG. 8 is an explanatory diagram of a gasket according to a conventional example.

FIG. 9 is an explanatory diagram of a gasket according to another conventional example.

FIG. 10 is an explanatory view of a gasket according to another conventional example.

[Explanation of symbols]

1 gasket 2 housing (one member) 3 Housing (other member) 4 mounting groove 4a groove bottom 4b side wall 4c, 7b Gap side end 5 Seal part 6 gap 7 Projection prevention protrusion 7a outer diameter surface 8, 9 gap 10,11 Seal lip 12 Pressure receiving groove 13, 14, 15 Chamfer 14a, 15a groove bottom end

Claims (4)

[Claims] 1. A gasket (1) which is mounted in a mounting groove (4) provided in one member (2) of two members (2) and (3) facing each other and is in close contact with the other member (3). In the above, by contacting an inner surface of the mounting groove (4) with a surface of the seal portion (5) that is in close contact with the two members (2) and (3) and seals the pressure fluid, the surface opposite to the pressure load direction, A gasket comprising a protrusion preventing protrusion (7) for preventing the seal portion (5) from protruding into a gap (6) between the two members (2) and (3). 2. The gasket according to claim 1, wherein the height dimension (H ₁ ) of the protrusion preventing protrusion (7) is set smaller than the depth dimension (D) of the mounting groove (4), and the two members (2) ) Even when the gap (6) between the protrusions (3) is closed, between the protrusion preventing protrusion (7) and the groove bottom surface (4a) of the mounting groove (4) and between the protrusion preventing protrusion (7) and the other member. A gasket, wherein gaps (8) and (9) are formed between the gasket and (3), respectively. 3. The gasket according to claim 1, wherein chamfered portions (14) and (15) are provided on the peripheral edge of the mounting groove (4) and the peripheral edge of the protrusion prevention protrusion (7), respectively. ), The end portion (14a) of the chamfered portion (14) provided on the protrusion preventing protrusion (7) on the bottom surface side of the mounting groove is the mounting groove (4).
A gasket characterized by being located closer to the bottom surface of the mounting groove than the end (15a) of the chamfered portion (15) provided on the bottom surface of the mounting groove groove. 4. The gasket according to claim 1, 2 or 3, wherein the seal portion (5) of the gasket (1) is in close contact with the groove bottom surface (4a) of the mounting groove (4).
0) and the sealing lip (1) that is in close contact with the other member (3).
1) and a pressure receiving groove (12) provided between the seal lips (10) and (11).