JP2021167616A - Metal gasket - Google Patents

Abstract

To provide a metal gasket that can maintain sealability for deformation of a member to be fitted.SOLUTION: A metal gasket 1 includes: a pair of fork parts 2 extending in a radial direction; a connection part 3 for connecting base parts 2c of the fork parts 2 to each other; and a lip part 4 projecting on an opposite side in a compression direction from a tip side of the fork part 2. The connection part 3 has an outside surface 3a that is a curved surface. The fork part 2 is formed so that an inclination angle of an inside surface 2b is larger than that of an outside surface 2a with reference to a radial direction and has tapered shape.SELECTED DRAWING: Figure 2

Description

The present invention relates to metal gaskets used for sealing containers, machines, equipment and the like.

Conventionally, metal gaskets are used under harsh conditions such as high temperature, extremely low temperature, high pressure, and high vacuum where resin or rubber O-rings cannot be used, and are connecting parts for containers, machines, equipment, etc. The gap between the attached members is sealed in a compressed state by being sandwiched between the attached members.

The metal gaskets shown in FIGS. 5C and 6A to 6C of Patent Document 1 have a substantially U-shaped cross section from a pair of fork portions extending in the radial direction and a connecting portion for connecting the base portions of the fork portions. A lip portion protruding in the opposite direction to the compression direction is formed on the tip end side of each fork portion. Such a metal gasket is arranged and used in a state where a pair of forks are press-fitted between the members to be attached so as to approach each other. At this time, a force that receives the pressure of the fluid to be sealed and separates them from each other acts on the pair of forks, a force due to the so-called self-boosting function and an elastic restoring force of its own, and the sealing surface of the lip portion is applied to the member to be attached. Each is pressure-welded to ensure sealing performance. From this, the lip portion can be made to follow the change in the size of the gap due to the deformation of the attached member, and stable sealing property can be exhibited.

Microfilm of Jitsugyo No. 60-121114 (Jitsukaisho No. 62-28958) (Page 2, Fig. 5, Fig. 6)

The metal gasket of Patent Document 1 has a substantially U-shaped cross section, and its inner edge is composed of a substantially semi-arc and a pair of substantially straight lines connected to the substantially semi-arc. The shape and outer edge are a straight line that divides the connecting part, a pair of straight chamfered lines that are connected to both ends of the straight line, a straight line that is connected to the chamfered line and separates the forks that are parallel to each other, and the fork part of the outer edge. It has a cross-sectional shape consisting of a mountain-shaped bending line connected to a straight line for partitioning and a mountain-shaped bending line for partitioning the lip portion, and is formed in a tapered shape in which the wall thickness of the fork portion gradually decreases toward the tip side. On the other hand, the fork part is mainly deformed to follow the lip part. From this, when the deformation of the attached member becomes large, stress is concentrated in the substantially central portion in the radial direction of the fork portion and local deformation occurs, so that the contact angle of the lip portion with respect to the attached member changes significantly and the seal is sealed. There was a risk that the surface would move and the sealing performance would deteriorate.

The present invention has been made by paying attention to such a problem, and an object of the present invention is to provide a metal gasket capable of maintaining a sealing property against deformation of a member to be attached.

In order to solve the above problems, the metal gasket of the present invention is used.
A metal gasket comprising a pair of forks extending in the radial direction, a connecting portion for connecting the base portions of the fork portions, and a lip portion protruding from the tip end side of the fork portion to the opposite side in the compression direction.
The outer surface of the connecting portion is a curved surface.
The fork portion has an inner surface having a larger inclination angle with respect to the radial direction than the outer surface, and has a tapered shape.
According to this, when the attached member is deformed, a force is applied to the lip portion, and the metal gasket is easily deformed with the central portion of the connecting portion as a base point. As a result, the contact angle of the lip portion with respect to the attached member is maintained, the sealing surface is less likely to move, and the lip portion can be made to follow the attached member, so that the sealing property can be maintained.

The focal point on the inner surface of the connecting portion may be located closer to the connecting portion than the focal point on the outer surface of the connecting portion.
According to this, since the base portion of the fork portion is formed to be thicker than the central portion of the connecting portion, the metal gasket can be more easily deformed with the central portion of the connecting portion as the base point with respect to the deformation of the attached member. In addition, the stress acts on the fork portion substantially uniformly, so that it is not easily damaged.

The inner surface of the connecting portion may be a curved surface.
According to this, since stress is likely to act substantially uniformly on the connecting portion, the metal gasket can be deformed in a well-balanced manner with the central portion of the connecting portion as a base point.

The outer surfaces of the pair of forks may be parallel to each other.
According to this, since the amount of deformation of the fork portion with respect to the deformation of the attached member can be reduced, the contact angle of the lip portion with respect to the attached member can be easily maintained.

It may be formed symmetrically with respect to the radial direction.
According to this, since stress is likely to be applied to the connecting portion and the fork portion substantially uniformly, the metal gasket can be deformed in a well-balanced manner with the central portion of the connecting portion as a base point.

The inner surface of the fork portion may be formed with a straight cross section.
According to this, when the metal gasket is deformed, stress can be applied evenly to the fork portion in the radial direction.

The lip portion includes a tip surface that inclines from the tip side of the fork portion toward the base side in the direction opposite to the compression direction, a seal surface that extends from the tip surface toward the base side in the radial direction, and the fork portion. It is provided with a proximal end surface that rises from the outer surface toward the sealing surface on the opposite side in the compression direction.
An orthogonal bent surface or a valley-shaped curved surface may be formed in a rising region where the base end surface rises from the outer surface of the fork portion.
According to this, when the attached member is deformed, a force is applied to the lip portion, the base side of the fork portion is deformed with the central portion of the connecting portion as the base point, and the rising region near the seal surface is deformed on the tip end side of the fork portion. .. As a result, the contact angle of the lip portion with respect to the attached member is maintained, the sealing surface is less likely to move, and the lip portion can be made to follow the attached member, so that the sealing property can be maintained. In addition, since the tip surface of the lip portion is inclined, the sealing width of the sealing surface can be narrowed, so that when a force is applied to the lip portion, the sealing surface does not move and the rising region is easily deformed.

In the metal gasket, a portion composed of an outer surface having a curvature is used as a connecting portion, and a portion whose cross section extends linearly in the radial direction is used as a fork portion.

It is sectional drawing which shows the state which the metal gasket of Example 1 which concerns on this invention is attached in the seal groove formed between the attached members. It is sectional drawing of the metal gasket of Example 1. FIG. It is sectional drawing which shows the deformed state of the metal gasket when the gap of a seal groove is narrowed by the deformation of the attached member. It is sectional drawing which shows the deformed state of the metal gasket when the gap of a seal groove widens by the deformation of the attached member. It is sectional drawing of the metal gasket of Example 2 which concerns on this invention. It is sectional drawing of the metal gasket of Example 3 which concerns on this invention. It is sectional drawing of the metal gasket of Example 4 which concerns on this invention. It is sectional drawing of the metal gasket of Example 5 which concerns on this invention. It is sectional drawing of the metal gasket of Example 6 which concerns on this invention. It is sectional drawing which shows the modification of the lip part in an Example.

A mode for carrying out the metal gasket according to the present invention will be described below based on examples.

The metal gasket according to the first embodiment will be described with reference to FIGS. 1 to 4. Hereinafter, in this embodiment, the top and bottom of the paper surface of FIG. 2 will be described as the axial direction, and the left and right sides of the paper surface of FIG. 2 will be described as the outer diameter and the inner diameter, respectively.

The metal gasket 1 of the present invention is used under conditions such as high temperature, extremely low temperature, high pressure, and high vacuum. For example, as shown in FIG. 1, a connecting portion of a container, a machine, an equipment, or the like is connected. These mounted members 10, 11 are arranged in an annular seal groove 12 formed between the mounted members 10, 11 and are compressed in the axial direction by being sandwiched by the mounted members 10, 11. It seals the space. In FIG. 1, the metal gasket 1 is in a compressed state by receiving an initial load due to tightening of bolts or the like (not shown) used when connecting the attached members 10 and 11, and this is the state of the metal gasket 1. Initial state. Furthermore, it is assumed that the inner diameter side of the metal gasket 1 is filled with the sealed fluid.

As shown in FIG. 2, the metal gasket 1 of the first embodiment has an annular shape and a pair of fork portions 2 extending in the radial direction, and a base portion 2c of the pair of fork portions 2 at the outer diameter edge of the metal gasket 1. It is composed of a connecting portion 3 for connecting the two, and a lip portion 4 having an annular sealing surface 4b protruding from the tip end side of the fork portion 2 to the opposite side in the compression direction. The metal gasket 1 shown in FIG. 2 is in a state before being compressed by the attached members 10 and 11 (hereinafter referred to as a natural state), and at this time, the outer surfaces 2a of the pair of fork portions 2 are substantially parallel to each other. Is doing.
Furthermore, the direction in which the fork portions 2 approach each other will be described as the compression direction, that is, the direction in which the fork portions 2 approach each other in the axial direction will be described as the compression direction in FIG.

Further, as shown in FIG. 2, the metal gasket 1 has a substantially U-shaped cross section in which a pair of fork portions 2 extending in the radial direction are connected by a semicircular annular connecting portion 3 in a cross-sectional view. The radial length L1 of the fork portion 2 is longer than the axial outer diameter length R of the connecting portion 3 (L1> R), and preferably the fork with respect to the axial outer diameter length R of the connecting portion 3. The ratio L1 / R of the radial length L1 of the portion 2 may be 1.1 to 1.7. Furthermore, since the cross section of the metal gasket 1 is formed line-symmetrically with respect to the diameter line and the upper and lower fork portions 2 and the upper and lower lip portions 4 have substantially the same configuration, the upper fork portion 2 and the lip portion are formed. 4 will be described in detail, and the description of the lower fork portion 2 and the lip portion 4 will be omitted.

Further, the metal gasket 1 is formed by applying a coating treatment to a base material made of a nickel alloy or the like with a surface treatment agent such as silver or fluororesin. The coating with the surface treatment agent may be formed at least on the outer surface 2a side where the lip portion 4 in contact with the attached members 10 and 11 is provided.

The connecting portion 3 includes an outer surface 3a located on the outer diameter side and an inner surface 3b located on the inner diameter side. The outer surface 3a and the inner surface 3b are curvature centers C1 and C2 as different focal points located between the pair of fork portions 2, and curved surfaces having a constant curvature, respectively. Further, the center of curvature C2 of the inner surface 3b is located on the connecting portion 3 side, that is, the outer diameter side of the center of curvature C1 of the outer surface 3a, and the radius of curvature of the inner surface 3b becomes smaller, so that the curvature of the inner surface 3b is the outer surface. The curvature of the inner surface 3b is larger than the curvature of the outer surface 3a, that is, the inner surface 3b is more curved than the outer surface 3a. Therefore, the connecting portion 3 is formed to have the thinnest wall thickness at the center in the axial direction and the thickest wall thickness near the boundary between the fork portion 2 and the base portion 2c.

The fork portion 2 includes an outer surface 2a located on the outer side in the axial direction, an inner surface 2b located on the inner side in the axial direction, and an end surface 2d located on the inner diameter end. The outer surface 2a is a plane extending in the radial direction, and the inner surface 2b is formed by a plane extending while tilting upward from the outer diameter to the inner diameter. That is, the fork portion 2 is formed in a tapered shape in which the inclination angle with respect to the radial direction is larger than that of the outer surface 2a on the inner surface 2b, and the wall thickness of the fork portion 2 gradually decreases from the base portion 2c to the inner diameter. The inclination angle α with respect to the radial direction of the inner surface 2b is about 3 to 30 degrees, preferably 5 to 10 degrees.

Further, in the fork portion 2, the base portion 2c connected by the connecting portion 3 extends to the connecting portion 3 side, that is, the outer diameter side from the curvature center C2 of the inner surface 3b of the connecting portion 3. The metal gasket 1 is formed to have the thickest wall thickness at the base portion 2c of the fork portion 2 and the thinnest wall thickness at the inner diameter end of the outer surface 2a of the fork portion 2.

The lip portion 4 has a tip surface 4a which is an inclined plane extending upward from the upper end of the end surface 2d with an outer diameter, a sealing surface 4b which is a plane extending radially from the tip surface 4a toward the outer diameter, and a fork portion. It is provided with a base end surface 4c that rises upward from the outer surface 2a of 2 toward the seal surface 4b. A minute chamfer (not shown) is provided between the tip surface 4a and the seal surface 4b. The base end surface 4c includes a flat surface 4d extending in the axial direction on the sealing surface 4b side and a curved surface 4e on the rising region 41 side, which will be described later. Further, the connecting portion 4f between the sealing surface 4b and the base end surface 4c is formed by R chamfering. Furthermore, the inclination angle β with respect to the radial direction of the tip surface 4a is about 10 to 70 degrees, preferably 30 to 50 degrees.

A rising region 41 in which the base end surface 4c rises from the outer surface 2a of the fork portion 2 is provided, and the rising region 41 forms a curved surface such that the center of curvature is located outside the metal gasket 1 and above the rising region 41. A valley-shaped curved surface 42 is formed. The center of curvature may be located outside the metal gasket 1.

Next, sealing between the attached members 10 and 11 by the metal gasket 1 will be described. When the metal gasket 1 in the natural state shown in FIG. 2 is sandwiched by the attached members 10 and 11 from above and below, the attached members 10 and 11 come into contact with the sealing surfaces 4b of the pair of lip portions 4 and then are pressed against each other. The pair of fork portions 2 are deformed so as to approach each other in the vertical direction, and are in the initial state (see FIG. 1). Therefore, the sealing surface 4b seals between the attached members 10 and 11.

Next, sealing by the metal gasket 1 when the attached members 10 and 11 are deformed due to heat shrinkage or thermal expansion due to a change in ambient temperature will be described. As shown in FIG. 3, when the vertical gap between the seal grooves 12 is narrowed due to the deformation of the attached members 10 and 11 from the initial state, the amount of deformation of the metal gasket 1 is compared with the initial state (see FIG. 3 two-dot chain line). Increases and the force acting on the metal gasket 1 increases. At this time, the metal gasket 1 is deformed with the substantially central portion in the axial direction of the connecting portion 3 formed thinly on the outer diameter side as a base point, so that the pair of fork portions 2 are deformed so as to approach each other in the vertical direction. Along with this, the rising region 41 close to the sealing surface 4b on the inner diameter side is deformed so that the angle formed with the outer surface 2a becomes narrower. Therefore, even if the vertical gap between the seal grooves 12 is narrowed, the contact angle of the lip portion 4 with respect to the attached members 10 and 11 is maintained, the sealing surface 4b is less likely to move, and the lip portion 4 follows the attached members 10 and 11. Therefore, the sealing property is maintained.

Further, as shown in FIG. 4, when the vertical gap between the seal grooves 12 becomes wider due to the deformation of the attached members 10 and 11 from the initial state, the metal gasket 1 is compared with the initial state (see FIG. 4 two-dot chain line). The amount of deformation of the metal gasket 1 is reduced, and the force acting on the metal gasket 1 is reduced. At this time, the metal gasket 1 is deformed with the substantially central portion in the axial direction of the connecting portion 3 formed thinly on the outer diameter side as a base point, so that the pair of fork portions 2 are deformed so as to be separated from each other. Along with this, the rising region 41 close to the sealing surface 4b on the inner diameter side is deformed so that the angle formed with the outer surface 2a becomes wider. Therefore, even if the vertical gap between the seal grooves 12 is widened, the contact angle of the lip portion 4 with respect to the attached members 10 and 11 is maintained, the sealing surface 4b is less likely to move, and the lip portion 4 is attached to the attached members 10 and 11. Since it can be made to follow, the sealing property is maintained.

Further, since the lip portion 4 has a tip surface 4a that is inclined from the tip end side of the fork portion 2 toward the base portion 2c side in the opposite direction in the compression direction, the seal width of the seal surface 4b can be narrowed, so that the lip portion 4 can be narrowed. When a force is applied to 4, the rising region 41 is easily deformed without the sealing surface 4b moving.

Further, since the base end surface 4c is formed of the flat surface 4d on the sealing surface 4b side and the curved surface 4e on the rising region 41 side, stress is applied to the curved surface 4e as compared with the flat surface 4d when a force is applied to the lip portion 4. Is easy to concentrate, so that the amount of deformation of the rising region 41 can be controlled by the combination of the plane 4d and the curved surface 4e on the base end surface 4c.

Further, since the fork portion 2 is formed in a tapered shape in which the wall thickness gradually decreases toward the inner diameter side, the rising region 41 can be more easily deformed on the inner diameter side. Specifically, in the metal gasket 1, since the wall thickness at the inner diameter end of the outer surface 2a of the fork portion 2 forming the boundary portion with the rising region 41 is formed to be the thinnest, the rising region 41 is more easily deformed.

Further, since the seal surface 4b is curved in a mountain shape, the seal surface 4b can be brought into linear contact with the mounted members 10 and 11 in the circumferential direction to narrow the seal width, so that the lip portion 4 can be narrowed. It is easy to deform the rising region 41 in a state where the seal surface 4b is surely in contact with the seal surface 4b when a force is applied to the surface.

Further, since the connection portion 4f between the seal surface 4b and the base end surface 4c is R-chamfered, the R-chamfered connection portion 4f contacts even if the seal surface 4b moves when a force is applied to the lip portion 4. By doing so, chamfering is prevented, so that the sealing property can be stably maintained.

Further, as shown in FIG. 2, in the metal gasket 1 in the natural state, the outer surfaces 2a of the pair of fork portions 2 are parallel to each other, so that the amount of deformation of the fork portion 2 with respect to the deformation of the attached members 10 and 11 is reduced. Therefore, the contact angle of the lip portion 4 with respect to the attached members 10 and 11 can be easily maintained.

Further, since the inner surface 2b of the fork portion 2 is formed with a straight cross section, stress can be applied evenly to the fork portion 2 in the radial direction when the metal gasket 1 is deformed.

Further, since the inner surface 3b of the connecting portion 3 is a curved surface, stress can be easily applied to the connecting portion 3 substantially uniformly, so that the metal gasket 1 is deformed in a well-balanced manner with the substantially central portion in the axial direction of the connecting portion 3 as a base point. Can be made to.

Further, since the outer surface 3a of the connecting portion 3 is a curved surface having a constant curvature, stress can be more easily applied to the connecting portion 3 more uniformly. The gasket 1 can be deformed in a well-balanced manner.

Further, since the metal gasket 1 is formed symmetrically in cross-sectional line in the compression direction, that is, in the axial direction, stress is likely to be applied to the connecting portion 3 and the fork portion 2 substantially uniformly, so that the shaft of the connecting portion 3 is easily formed. The metal gasket 1 can be deformed in a well-balanced manner with the substantially central portion in the direction as a base point.

As described above, the outer surface 3a of the connecting portion 3 is curved, and the fork portion 2 has an inner surface 2b formed to have a larger inclination angle with respect to the radial direction than the outer surface 2a, and has a tapered shape. Since the center of curvature C2 of the inner surface 3b of the connecting portion 3 is located on the connecting portion 3 side, that is, on the outer diameter side of the center of curvature C1 of the outer surface 3a of the connecting portion 3, the base portion 2c of the fork portion 2 and the connecting portion are connected. The boundary portion with 3 is formed to be thicker than the substantially central portion in the axial direction of the connecting portion 3, and the metal gasket 1 is formed with the substantially central portion in the axial direction of the connecting portion 3 as a base point against deformation of the attached members 10 and 11. Since it can be easily deformed, when the attached members 10 and 11 are deformed, a force is applied to the lip portion 4, and the metal gasket 1 is formed on the outer diameter side of the fork portion 2 with the substantially central portion of the connecting portion 3 in the axial direction as a base point. Is deformed and the rising region 41 close to the sealing surface 4b is deformed on the inner diameter side of the fork portion 2. As a result, the contact angle of the lip portion 4 with respect to the attached members 10 and 11 is maintained, the sealing surface 4b is less likely to move, and the lip portion 4 can be made to follow the attached members 10 and 11, so that the sealing property is improved. Can be maintained. In addition, since the stress acts on the fork portion 2 substantially uniformly, local deformation due to the concentration of stress on the fork portion 2 can be prevented, and the fork portion 2 is less likely to be damaged.

Further, since the metal gasket 1 has a substantially U-shaped cross section, it is easy to follow the deformation of the attached members 10 and 11 and the stress is easily dispersed, so that the life of the metal gasket 1 can be extended.

Further, since the inner diameter side of the metal gasket 1 is filled with the sealed fluid, a force that causes the pair of upper and lower fork portions 2 to separate from each other by receiving the pressure of the sealed fluid from the inner diameter side is exerted by a so-called self-boosting function. By acting, the sealing surface 4b of the lip portion 4 is pressure-welded to the attached members 10 and 11, respectively, and the sealing property is ensured.

The metal gasket according to the second embodiment will be described with reference to FIG. It should be noted that the description of the same configuration as that of the first embodiment and the overlapping configuration will be omitted.

In the metal gasket 101 of the second embodiment, as shown in FIG. 5, the fork portion 102 has an outer surface 102a located on the outer side in the axial direction, and the outer surface 102a is connected to the outer surface 3a of the connecting portion 3 on the base 2c side of the fork portion 102. It is composed of an inclined plane 121 extending upward from the inclined plane 121 and a plane 122 connected to the inclined plane 121 and extending in the radial direction. That is, as compared with the case where the outer surface 2a of the fork portion 2 extends linearly from the base portion 2c side to the inner diameter as in the first embodiment, the outer surface is formed by forming the inclined plane 121 on the base portion 2c side of the fork portion 102. The amount of protrusion of 102a to the outside in the axial direction is small.

According to this, when the upper and lower gaps of the seal groove 12 are narrowed due to the deformation of the mounted members 10 and 11 from the initial state and the metal gasket 1 is deformed in the compression direction, the mounted members 10 and 11 (not shown in FIG. 5). The inclined flat surface 121 is less likely to come into contact with the base portion 2c side of the fork portion 102, and only the lip portion 4 can be brought into contact with the fork portion 102, so that the contact angle of the lip portion 4 is easily maintained.

The metal gasket according to the third embodiment will be described with reference to FIG. It should be noted that the description of the same configuration as that of the first embodiment and the overlapping configuration will be omitted.

In the metal gasket 201 of the third embodiment, as shown in FIG. 6, the outer surface 203a and the inner surface 203b of the connecting portion 203 have a curvature center C3 as the same focal point located between the pair of fork portions 202, respectively. It is a curved surface having a constant curvature. That is, the outer surface 203a and the inner surface 203b are formed concentrically, and the connecting portion 203 is formed to have the same wall thickness.

The fork portion 102 is formed in a tapered shape in which the inclination angle of the inner surface 102b is larger than that of the outer surface 102a and the wall thickness of the fork portion 102 gradually decreases toward the inner diameter side. Further, in the fork portion 102, the base portion 102c connected by the connecting portion 103 extends from the center of curvature C3 to the connecting portion 103 side, that is, to the outer diameter side. Further, the outer diameter end of the outer surface 102a of the fork portion 102 extends to the outer diameter side of the inner diameter end of the inner surface 102b.

The lip portion 204 includes a tip surface 4a, a sealing surface 4b, and a base end surface 204c, and the base end surface 204c is formed only from a curved surface 204e. Further, a rising region 241 in which the base end surface 204c rises from the outer surface 202a of the fork portion 202 is provided, and a valley-shaped curved surface 242 extending upward from the outer surface 202a is formed in the rising region 241. Further, the base end surface 204c is formed from a curved surface having the same curvature as the valley-shaped curved surface 242, and is smoothly connected to the valley-shaped curved surface 242.

According to this, when the attached members 10 and 11 are deformed, a force is applied to the lip portion 204, the entire connecting portion 203 is deformed substantially uniformly on the outer diameter side, and the sealing surface 4b is formed on the inner diameter side of the fork portion 202. Since the stress tends to act substantially uniformly from the near rising region 241 to the proximal end surface 204c, the contact angle of the lip portion 204 with respect to the mounted members 10 and 11 (not shown in FIG. 6) is likely to be maintained.

The metal gasket according to the fourth embodiment will be described with reference to FIG. It should be noted that the description of the same configuration as that of the first embodiment and the overlapping configuration will be omitted.

As shown in FIG. 7, the metal gasket 301 of the fourth embodiment has a cross-sectional shape obtained by reversing the cross-sectional shape substantially the same as that of the metal gasket 1 of the first embodiment in the radial direction, that is, the connecting portion 303 has a cross-sectional shape. It is arranged on the inner diameter side, and the lip portion 304 is arranged on the outer diameter side. Such a metal gasket 301 is effective when the outer diameter side of the metal gasket 301 is filled with the sealed fluid, and the pair of upper and lower fork portions 302 receive pressure from the outer diameter side of the sealed fluid. A force that separates the members by a so-called self-pressure boosting function acts, and the sealing surfaces 304b of the lip portion 304 are pressed against the mounted members 10 and 11 (not shown in FIG. 7) to ensure sealing performance. ..

The metal gasket according to the fifth embodiment will be described with reference to FIG. It should be noted that the description of the same configuration as that of the first embodiment and the overlapping configuration will be omitted.

As shown in FIG. 8, the metal gasket 401 of the fifth embodiment has a larger amount of protrusion of the lip portion 404 outward in the axial direction than the metal gasket 1 of the first embodiment.

Specifically, the lip portion 404 has a longer axial dimension of the plane 404d forming the proximal end surface 404c as compared with the first embodiment, and the corner portion between the tip end surface 404a and the end surface 402d of the fork portion 402 constitutes the proximal end surface 404c. It is formed axially outward from the valley-shaped curved surface 42 in the rising region 41. That is, the lip portion 404 has a shape in which the seal surface 404b is significantly separated from the outer surface 402a of the fork portion 402 in the axial direction. In the first embodiment, the corners of the tip surface 404a and the end surface 402d and the valley-shaped curved surface 42 are formed to have substantially the same axial position.

According to this, when the upper and lower gaps of the seal groove 12 are narrowed due to the deformation of the mounted members 10 and 11 from the initial state and the metal gasket 401 is deformed in the compression direction, the mounted members 10 and 11 (not shown in FIG. 8). The outer surface 402a is less likely to come into contact with the base portion 402c side of the fork portion 402, and only the lip portion 404 can be brought into contact with the fork portion 402, so that the contact angle of the sealing surface 404b of the lip portion 404 is maintained. The movement of the sealing surface 404b is less likely to occur.

Further, the radial length L2 of the fork portion 402 is shorter than the radial length L1 (see FIG. 2) (L2 <L1), and the connecting portion 403 is compared with the first embodiment while maintaining the outer diameter length R. Therefore, the wall thickness is thin, and the base portion 402c side of the fork portion 402 is also thin walled. The rigidity of the metal gasket 401 is higher as the radial length L2 of the fork portion 402 is shorter, and is lower as the base portion 402c side of the connecting portion 403 and the fork portion 402 is thinner, and the fork portion 402 is shorter. The amount of deformation acting directly from the portion 402 on the lip portion 404 provided at the end of the fork portion 402 is reduced. On the other hand, since the amount of protrusion of the lip portion 404 to the outside in the axial direction is large, the amount of deformation allowed by the rising region 41 of the lip portion 404 is large. Therefore, when the metal gasket 401 is compressed inward in the axial direction by the mounted members 10 and 11, the lip portion 404 is deformed in the same manner as in the first embodiment and can follow the mounted members 10 and 11, and is mounted. The state of contact with the members 10 and 11 can be maintained.

The metal gasket according to the sixth embodiment will be described with reference to FIG. It should be noted that the description of the same configuration as that of the first embodiment and the overlapping configuration will be omitted.

As shown in FIG. 9, the metal gasket 501 of the sixth embodiment has a smaller amount of protrusion of the lip portion 504 in the axial direction as compared with the metal gasket 1 of the first embodiment.

Specifically, the lip portion 504 has a shorter axial dimension of the plane 504d constituting the proximal end surface 504c as compared with the first embodiment, and the corner portion between the distal end surface 504a and the end surface 502d of the fork portion 502 constitutes the proximal end surface 504c. It is formed axially inward of the valley-shaped curved surface 42 in the rising region 41. That is, the thickness of the tip side of the lip portion 504, in other words, the tip side of the fork portion 502 is the thinnest.

According to this, when the attached members 10 and 11 are deformed, a force is applied to the lip portion 504, and stress acts on the inner diameter side of the fork portion 502 from the rising region 41 close to the sealing surface 504b to the proximal end surface 504c, thereby causing the lip. Since the tip of the fork portion 502 on which the portion 504 is formed is easily deformed, the contact angle of the lip portion 504 with respect to the attached members 10 and 11 (not shown in FIG. 9) is maintained, and the sealing surface 504b It is difficult for movement to occur.

Further, the radial length L3 of the fork portion 502 is longer than the radial length L1 (see FIG. 2) (L3> L1), and the connecting portion 503 is compared with the first embodiment while maintaining the outer diameter length R. Therefore, the wall thickness is increased, and the base portion 502c side of the fork portion 502 is also thickened. The rigidity of the metal gasket 501 is lower as the radial length L3 of the fork portion 502 is longer, and is higher as the base portion 502c side of the connecting portion 503 and the fork portion 502 is thicker, and the fork portion 502 is longer. The amount of deformation acting directly from the fork portion 502 on the lip portion 504 provided at the end of the fork portion 502 becomes large. On the other hand, since the amount of protrusion of the lip portion 504 to the outside in the axial direction is small, the amount of deformation allowed by the rising region 41 of the lip portion 504 is small. Therefore, when the metal gasket 501 is compressed inward in the axial direction by the mounted members 10 and 11, the lip portion 504 is deformed in the same manner as in the first embodiment and can follow the mounted members 10 and 11, and is mounted. The state of contact with the members 10 and 11 can be maintained.

Although examples of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these examples, and any changes or additions within the scope of the gist of the present invention are included in the present invention. Is done.

For example, it has been described that the metal gasket is sandwiched and fixed by the attached members 10 and 11 from the vertical direction, but the present invention is not limited to this, and for example, in the first to third, fifth and sixth embodiments, the outer diameter from the connecting portion of the metal gasket is increased. A fixed portion extending to the side may be provided and the non-fixed portion may be bolted, or in the fourth embodiment, a fixed portion extending from the connecting portion of the metal gasket to the inner diameter side may be provided and the non-fixed portion may be bolted. good.

Further, the shape of the lip portion may be freely formed, and may be formed, for example, in a trapezoidal cross section (see FIG. 10).

Further, although it has been explained that the connecting portion 4f between the seal surface and the base end surface is R-chamfered, the present invention is not limited to this, and C-chamfered may be used.

Further, it has been described that the tip surface is a flat surface extending upward from the upper end of the end face toward the outer diameter (inner diameter in the fourth embodiment), but the present invention is not limited to this, and the radial direction is not limited to this. It may be provided with an intervening surface extending to, in other words, the radial position where the lip portion is provided on the fork portion may be in the middle instead of the tip.

Further, in the above embodiment, the curvatures of the outer and inner surfaces of the connecting portion have been described as having a constant curvature, but the present invention is not limited to this, and the outer and inner surfaces of the connecting portion have a partial curvature change. You may. Further, the connecting portion may be a bent surface having, for example, a linear surface extending in the axial direction, as long as the outer surface is formed as a curved surface.

Further, in the above embodiment, it has been described that the rising region where the base end surface of the lip portion rises from the outer surface of the fork portion is configured as a valley-shaped curved surface extending while curving upward from the outer surface, but the present invention is not limited to this. The rising region may be configured as an orthogonal bending surface extending at a right angle upward from the outer surface of the fork portion.

1 Metal gasket 2 Fork part 2a Outer surface 2b Inner surface 2c Base 3 Connecting part 3a Outer surface 3b Inner surface 4 Lip part 4a Tip surface 4b Sealing surface 4c Base end surface 4d Flat surface 4e Curved surface 4f Connection part 10, 11 Attached member 41 Rising area 42 Valley shape Curved surface 101 Metal gasket 102 Fork part 103 Connecting part 121 Inclined flat surface 122 Flat surface 201 Metal gasket 202 Fork part 202a Outer surface 203 Connecting part 203a Outer surface 203b Inner surface 204 Lip part 204c Base end surface 204e Curved surface 241 Rising area 242 Valley-shaped curved surface 301 Metal gasket 302 Fork part 303 Connecting part 304 Lip part 304b Sealing surface 401 Metal gasket 402 Fork part 403 Connecting part 404 Lip part 404a Tip surface 404b Sealing surface 404c Base end surface 404d Flat surface 501 Metal gasket 504 Lip part 504a Tip surface 504b Sealing surface 504c Base end surface 504d Plane C1-C3 Center of curvature (focal)

Claims (7)

A metal gasket comprising a pair of forks extending in the radial direction, a connecting portion for connecting the base portions of the fork portions, and a lip portion protruding from the tip end side of the fork portion to the opposite side in the compression direction.
The outer surface of the connecting portion is a curved surface.
The fork portion is a metal gasket in which the inner surface is formed to have a larger inclination angle with respect to the radial direction than the outer surface and has a tapered shape. The metal gasket according to claim 1, wherein the focal point on the inner surface of the connecting portion is located closer to the connecting portion than the focal point on the outer surface of the connecting portion. The metal gasket according to claim 1 or 2, wherein the inner surface of the connecting portion is a curved surface. The metal gasket according to any one of claims 1 to 3, wherein the outer surfaces of the pair of forks are parallel to each other. The metal gasket according to any one of claims 1 to 4, which is formed symmetrically with respect to the radial direction. The metal gasket according to any one of claims 1 to 5, wherein the inner surface of the fork portion is formed with a straight cross section. The lip portion includes a tip surface that inclines from the tip side of the fork portion toward the base side in the direction opposite to the compression direction, a seal surface that extends from the tip surface toward the base side in the radial direction, and the fork portion. It is provided with a proximal end surface that rises from the outer surface toward the sealing surface on the opposite side in the compression direction.
The metal gasket according to any one of claims 1 to 6, wherein an orthogonal bent surface or a valley-shaped curved surface is formed in a rising region where the base end surface rises from the outer surface of the fork portion.

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