Gasket and seal structure assembled with same

Abstract

An annular gasket 10 for sealing between two members, a first member 1 and a second member 5, which are assembled facing each other, comprises: an annular first seal part 13 made of an elastic material, which is provided on the first member side of an annular core body 11, protrudes to the first member side and abuts on the first member; and an annular second seal part 21 made of an elastic material, which is provided on the second member side of the core body, protrudes to the second member side and abuts on the second member. The first seal part and the second seal part are provided so as not to be superimposed on each other when viewed in the facing direction of the first member and the second member, and are formed so as to be elastically deformed to fall to an outer diameter side when the two members are assembled.

Description

Gasket and seal structure to which it is attached

[0001] The present invention relates to an annular gasket for sealing between two members and a sealing structure to which the gasket is assembled.

[0002] Conventionally, gaskets having sealing portions that contact two members, a first member and a second member, respectively, have been known. For example, Patent Document 1 below discloses a metal gasket in which surface pressure agents that come into close contact with a cylinder or a cylinder head are provided on the front and back of a substrate made of a metal plate, and the centers of the surface pressure agents are offset from each other in the radial direction.

[0003] Patent No. 2785955

[0004] The above-mentioned Patent Document 1 discloses that the height of the surface pressure agent may be adjusted in order to adjust the surface pressure of the surface pressure agent, but if the height of the surface pressure agent is increased, there is a concern that a portion of the circumferential direction of the surface pressure agent may fall and twist in an unintended direction when fastening two components, thereby reducing sealing performance.

[0005] The present invention has been made in view of the above circumstances, and has as its object to provide a gasket that can improve sealing performance and a seal structure to which the gasket is assembled.

[0006] In order to achieve the above-mentioned object, configuration 1 of the gasket of the present invention is an annular gasket that seals between two members, a first member and a second member, that are assembled opposite each other, and is equipped with: an annular first seal portion made of an elastic material that is provided on the first member side of an annular core body, protruding toward the first member and abutting against the first member; and an annular second seal portion made of an elastic material that is provided on the second member side of the core body, protruding toward the second member and abutting against the second member, wherein the first seal portion and the second seal portion are arranged so as not to overlap each other when viewed in the opposing direction of the first member and the second member, and are formed so as to elastically deform so as to collapse toward the outer diameter when the two members are assembled.

[0007] The following description of the embodiments discloses that the gasket according to the present invention may include the following subsidiary configurations. <Configuration 2> In configuration 1, at least one of the first seal portion and the second seal portion may have a smaller radial dimension than its dimension in the opposing direction. <Configuration 3> In configuration 1 or 2, at least one of the first seal portion and the second seal portion may have a radial center at the tip in the protruding direction that is located closer to the outer diameter than a radial center at the base end that is closer to the core. <Configuration 4> In any one of configurations 1 to 3, the base end of at least one of the first seal portion and the second seal portion may have a corner on the outer diameter side that has a smaller radius of curvature than a corner on the inner diameter side in a radial cross section. <Configuration 5> In any one of configurations 1 to 4, the base end of at least one of the first seal portion and the second seal portion may have a groove-shaped recess extending circumferentially on the outer diameter side. <Configuration 6> In any one of Configurations 1 to 5, the core may further include an annular third seal portion made of an elastic material that is provided on one of the first and second members of the core body, protrudes toward the one member, and abuts against the one member, and the third seal portion may be formed to elastically deform so as to collapse toward the outer diameter side when the two members are assembled.

[0008] In order to achieve the above object, the sealing structure of the present invention is a sealing structure in which the gasket is assembled between two members, a first member and a second member, which are assembled opposite each other, and is characterized in that the annular sealed portion against which the first sealing portion provided on the first member side abuts and the annular sealed portion against which the second sealing portion provided on the second member side abuts do not overlap each other when viewed in the opposing direction.

[0009] The gasket of the present invention and the seal structure to which it is assembled have the above-described configuration, and therefore can improve sealing performance.

[0010] 1A and 1B are schematic longitudinal cross-sectional views showing a gasket according to one embodiment of the present invention and a seal structure to which the gasket is assembled. (a) is a schematic plan view of the gasket, and (b) is a cross-sectional view taken along the arrows X-X in (a). (b) are schematic longitudinal cross-sectional views of the gasket and the seal structure. (a) and (b) are schematic longitudinal cross-sectional views showing gaskets according to modified examples of the embodiment. (a) is a schematic longitudinal cross-sectional view showing a gasket according to a modified example of the embodiment, and (b) is a schematic longitudinal cross-sectional view of the gasket and the seal structure to which the gasket is assembled. (a) is a schematic longitudinal cross-sectional view showing a gasket according to a modified example of the embodiment, and (b) is a schematic longitudinal cross-sectional view of the gasket and the seal structure to which the gasket is assembled.

[0011] An example of a gasket according to an embodiment and a sealing structure to which the gasket is assembled will be described below with reference to the drawings. Note that in some drawings, some of the detailed reference numerals used in other drawings are omitted. Figures 1 to 6 are diagrams showing an example of a gasket according to this embodiment and an example of a sealing structure to which the gasket is assembled, as well as modified examples.

[0012] 1 to 3, the gasket 10 according to this embodiment is an annular gasket that seals between two members, a first member 1 and a second member 5, which are assembled facing each other. The gasket 10 is provided with an annular first seal portion 13 made of an elastic material that is provided on the first member 1 side of the annular core 11 and protrudes toward the first member 1 to abut against the first member 1, and an annular second seal portion 21 made of an elastic material that is provided on the second member 5 side of the core 11 and protrudes toward the second member 5 to abut against the second member 5. With this configuration, the gasket 10 is disposed between the two members, and the first seal portion 13 abuts against the first member 1, and the second seal portion 21 abuts against the second member 5, thereby sealing between the two members.

[0013] The first seal portion 13 and the second seal portion 21 are arranged so as not to overlap each other when viewed in the direction in which the first member 1 and the second member 5 face each other. With this configuration, when the two members are assembled, the portion where the first member 1 abuts against the first seal portion 13 and the portion where the second member 5 abuts against the second seal portion 21 are less likely to overlap when viewed in the direction in which they face each other. This reduces local stress concentration in the two members compared to a gasket in which the seal portions on both sides of the core body overlap when viewed in the direction in which they face each other. The first seal portion 13 and the second seal portion 21 are formed so as to elastically deform so as to collapse toward the outer diameter when assembled to the two members. With this configuration, the first seal portion 13 and the second seal portion 21 elastically deform so as to collapse toward the outer diameter when the two members are assembled, thereby preventing the first seal portion 13 and the second seal portion 21 from partially collapsing and twisting in an unintended direction in the circumferential direction, thereby improving sealing performance. Furthermore, compared to a configuration in which the seal position is narrowed by being formed to lean toward the inner diameter, the seal position is widened when the two components are assembled, so deflection due to narrowing of the diameter is less likely to occur and twisting is less likely to occur, thereby improving sealing performance. Furthermore, when the two components are tubular components that form the fluid flow paths 2, 6, the first seal portion 13 and the second seal portion 21 can be prevented from protruding toward the inner diameter, which makes it less likely to obstruct the flow of fluid.

[0014] As shown in Fig. 3, the seal structure according to the first embodiment has the gasket 10 assembled between two members, a first member 1 and a second member 5, which are assembled facing each other. In this seal structure, the annular sealed portion 4, which is contacted by the first seal portion 13 provided on the first member 1 side, and the annular sealed portion 8, which is contacted by the second seal portion 21 provided on the second member 5 side, do not overlap each other when viewed in the opposing direction. This configuration achieves the same effects as the gasket 10 described above. An example of a specific configuration will be described below.

[0015] As shown in Figures 1 and 3, the first member 1 and the second member 5 are tubular members that define fluid flow paths 2 and 6, respectively, and are provided with brim-shaped flanges 3 and 7 at one end that connect to the open ends of the flow paths 2 and 6. The first member 1 is formed so that the diameter of the flow path 2 is smaller than that of the flow path 6 of the second member 5, and the diameter of the flange 3 is smaller than that of the flange 7 of the second member 5. The flange 3 of the first member 1 and the flange 7 of the second member 5 are provided opposite each other via a gasket 10. The surface of the flange 3 of the first member 1 that faces the second member 5 defines the sealed portion 4 against which the first seal portion 13 abuts. The surface of the flange 7 of the second member 5 that faces the first member 1 defines the sealed portion 8 against which the second seal portion 21 abuts.

[0016] As shown in FIG. 2( a), the gasket 10 has an annular shape. As shown in FIGS. 1 and 2( b), the core body 11 of the gasket 10 is an annular plate. A circular through-hole 11a is provided in the center of the core body 11. The gasket 10 includes an annular first seal base 12 made of an elastic material and secured to the surface of the core body 11 facing the first member 1. The first seal base 12 is provided so as not to block the through-hole 11a of the core body 11. A first seal portion 13 is formed so as to protrude from the inner diameter end of the first seal base 12 toward the first member 1. The gasket 10 includes an annular second seal base 20 made of an elastic material and secured to the surface of the core body 11 facing the second member 5. Similar to the first seal base 12, the second seal base 20 is formed so as not to block the through-hole 11a of the core body 11. A second seal portion 21 is formed so as to protrude from the outer diameter side end of the second seal base portion 20 toward the second member 5 .

[0017] As shown in FIG. 2( b), the first seal portion 13 is formed so that its radial dimension decreases toward the tip end in the protruding direction. In other words, the radial dimension of the first seal portion 13 is greatest at the base end 13 a and smallest at the tip end 13 b. The radial dimension w1 of the first seal portion 13 (the radial dimension of the base end 13 a, which is the largest part) is smaller than the dimension h1 in the facing direction (protruding dimension). This configuration makes it easier for the first seal portion 13 to collapse toward the outer diameter when the two components are assembled. Here, the radial dimension w1 of the first seal portion 13 is the dimension at the base end 13 a, which is virtually flush with the surface of the first seal base 12 facing the first member 1. The dimension h1 of the first seal portion 13 along the facing direction is the dimension from the base end 13 a to the tip end 13 b of the first seal portion 13 in the protruding direction. The dimension w1 of the first seal portion 13 along the radial direction and the dimension h1 of the first seal portion 13 along the opposing direction may be set to appropriate dimensions so that the first seal portion 13 can easily collapse toward the outer diameter side.

[0018] The first seal portion 13 has a radial center b1 at the tip 13b in the protruding direction located radially outward of a radial center a1 at the base end 13a, which is located on the core body 11 side. This configuration makes it easier for the first seal portion 13 to collapse from the tip 13b toward the outer diameter when the two components are assembled. As shown in FIG. 2( a), the tip 13b is annular when viewed in the opposing direction (in a plan view). The tip 13b is formed as a flat surface parallel to the radial direction. The base end 13a is also annular and concentric with the tip 13b. The first seal portion 13 is formed such that an imaginary circle formed by the radial center b1 of the tip 13b is located radially outward of an imaginary circle formed by the radial center a1 of the base end 13a when viewed in the opposing direction.

[0019] In a radial cross-sectional view, the base end 14 of the first seal portion 13 is formed such that the radius of curvature of the outer diameter side corner 16 is smaller than the radius of curvature of the inner diameter side corner 15. With this configuration, the cross-sectional area of ​​the outer diameter side corner 16 of the first seal portion 13 tends to be smaller in a radial cross-sectional view than the inner diameter side corner 15, making it more likely to collapse toward the outer diameter side when the two members are assembled. The inner diameter side corner 15 of the base end 14 of the first seal portion 13 is formed into a concave curved surface that becomes outer diameter side toward the first member 1 side so as to have the above-mentioned radius of curvature. Furthermore, the outer diameter side corner 16 of the base end 14 of the first seal portion 13 is formed into a concave curved surface that becomes outer diameter side toward the second member 5 side. In other words, in a radial cross-sectional view, the inner diameter side corner 15 is formed into a more gently concave curved surface than the outer diameter side corner 16.

[0020] The outer diameter side surface of the base end 14 of the first seal portion 13 is provided with a groove-like recess 17 extending along the circumferential direction. This configuration allows the recess 17 to easily tilt the first seal portion 13 toward the outer diameter side when the two components are assembled. The recess 17 is provided to form a corner 16 on the outer diameter side of the base end 14 of the first seal portion 13. The recess 17 opens toward the outer diameter side and is provided around the entire circumference of the outer diameter side of the first seal portion 13. The recess 17 is formed into a concave curved surface such that the groove bottom and groove walls on both sides are continuous. The recess 17 is formed to be slightly recessed toward the inner diameter side relative to the outer diameter side surface that is continuous with the first member 1 side of the recess 17. The outer diameter side surface (outer diameter surface) and inner diameter side surface (inner peripheral surface) of the intermediate portion of the base end 14 of the first seal portion 13 in the protruding direction that is continuous with the first member 1 side are cylindrical. A tip end portion of the first seal portion 13 that is connected to the first member 1 side in the protruding direction is formed so that the dimension along the radial direction decreases toward the first member 1. The outer diameter side surface and the inner diameter side surface of this tip end portion are formed as inclined surfaces that slope toward the radial center b1 of the tip end 13b as they approach the tip end 13b.

[0021] The second seal portion 21 is formed so that its radial dimension decreases toward the tip end in the protruding direction. That is, the radial dimension of the second seal portion 21 is greatest at the base end 21a and least at the tip end 21b. The radial dimension w2 of the base end 21a of the second seal portion 21 is greater than the radial dimension w1 of the base end 13a of the first seal portion 13. With this configuration, if the gasket 10 is assembled with the second member 5 positioned below the first member 1, as shown in FIG. 3 , the elastic deformation of the lower second seal portion 21 is smaller than that of the first seal portion 13. Furthermore, because the second seal portion 21 is positioned radially outward of the first seal portion 13, the gasket 10 is more likely to maintain a stable posture.

[0022] Unlike the first seal portion 13, the second seal portion 21 has a radial dimension w2 greater than a dimension h2 along the facing direction. Here, the radial dimension w2 of the second seal portion 21 is, as described above, the dimension at the base end 21a, which is virtually flush with the surface of the second seal base 20 facing the second member 5. The dimension h2 of the second seal portion 21 along the facing direction is the dimension from the base end 21a to the tip 21b in the protruding direction of the second seal portion 21. Similar to the first seal portion 13, the radial center b2 of the tip 21b in the protruding direction of the second seal portion 21 is located radially outward of the radial center a2 of the base end 21a. With this configuration, even if the radial dimension w2 is greater than the dimension h2 along the facing direction, the second seal portion 21 is more likely to collapse from the tip 21b toward the outer diameter when the two members are assembled. As described above, the tip 21b is formed in an annular shape when viewed in the facing direction, and is formed as a flat surface parallel to the radial direction. The base end 21a is also formed in an annular shape and is formed concentrically with the tip 21b. In other words, the second seal portion 21 is formed so that an imaginary circle formed by the radial center b2 of the tip 21b is located on the outer diameter side of an imaginary circle formed by the radial center a2 of the base end 21a when viewed in the facing direction.

[0023] Unlike the first seal portion 13, the second seal portion 21 has an inner diameter side surface that is substantially entirely inclined toward the distal end 21b so as to converge to the radial center b2 of the distal end 21b. Furthermore, the outer diameter side surface of a portion of the base end 22 of the second seal portion 21 in the protruding direction that connects to the second member 5 side is cylindrical. The outer diameter side surface of a distal end portion that connects to the outer diameter side surface of the portion of the base end 22 in the protruding direction of the second seal portion 21 is inclined toward the radial center b2 of the distal end 21b. Unlike the first seal portion 13, the base end 22 of the second seal portion 21 has an inner diameter corner 23 and an outer diameter corner 24 that have substantially the same radius of curvature in a radial cross section. Even with this configuration, the second seal portion 21 has an inner diameter side surface that is inclined toward the outer diameter, and the radial center b2 of the tip 21 b in the protruding direction is located closer to the outer diameter than the radial center a2 of the base end 21 a, so that the second seal portion 21 is more likely to collapse toward the outer diameter when the two members are assembled. Furthermore, the outer diameter side surface of the protruding portion of the base end 22 of the second seal portion 21 at the midpoint of the protruding direction that connects to the second member 5 side is cylindrical, so that the second seal portion 21 is more likely to collapse toward the outer diameter when the two members are assembled.

[0024] As shown in FIGS. 1 and 3 , the gasket 10 is assembled so that the through hole 11a of the core body 11 is substantially concentric with the flow path 2 of the first member 1 and the flow path 6 of the second member 5. When a load acts on the gasket 10 assembled between the two members in the opposing direction of the two members, the first seal portion 13 and the second seal portion 21 elastically deform so as to collapse toward the outer diameter, as shown in FIG. 3 . In the illustrated example, the first seal portion 13 collapses toward the outer diameter so that its outer diameter side surface contacts the first seal base 12. Meanwhile, the second seal portion 21 collapses toward the outer diameter to such an extent that its outer diameter side surface does not contact the second seal base 20. The sealed portion 4 provided on the flange portion 3 of the first member 1, which contacts the elastically deformed first seal portion 13, and the sealed portion 8 provided on the flange portion 7 of the second member 5, which contacts the second seal portion 21, are arranged so as not to overlap each other when viewed in the opposing direction. Furthermore, the inner diameter of the sealed portion 8 of the second member 5 is larger than the outer diameter of the sealed portion 4 of the first member 1. In this way, even if the first member 1 and the second member 5 have different inner and outer diameter dimensions of the flange portions 3, 7, they can be sealed by the first seal portion 13 and the second seal portion 21 of the gasket 10 configured as described above.

[0025] Next, gaskets according to modified examples will be described with reference to Figures 4 to 6. In each of the following modified examples, differences from the previously described example will be mainly described, and explanations of similar configurations will be omitted or briefly explained. In each modified example, explanations of the same effects as those of the previously described example will also be omitted or briefly explained.

[0026] FIG. 4A schematically illustrates a gasket 10A according to a first modification. This gasket 10A differs from the above-described examples primarily in the configuration of the recess 17A in the first seal portion 13A and the presence of a recess 25 in the second seal portion 21A. The first seal portion 13A has a cylindrical inner surface that is closer to the first member 1 than the inner corner 15. The outer surface of the base end 14 of the first seal portion 13A also has a recess 17A that is recessed further inward than the above-described example. This recess 17A has a rectangular groove shape in a radial cross section. One side of the groove width direction is defined by the first seal base 12, the other side is defined by a groove wall 17b facing the first seal base 12, and the groove bottom is defined by a cylindrical groove bottom 17a that faces the outer diameter direction. The groove bottom 17a is located at a position that generally coincides with the radial center b1 of the tip 13b of the first seal portion 13A. In the illustrated example, the groove bottom 17a is located slightly radially inward of the radial center b1 of the tip 13b of the first seal portion 13A. The radial dimension of the base end 14 where the recessed portion 17A of the first seal portion 13A is located is smaller than the radial dimension w1 of the entire first seal portion 13A.

[0027] The second seal portion 21A, similar to the first seal portion 13A, has an inner diameter side surface closer to the second member 5 than the inner diameter corner portion 23, which is cylindrical over substantially the entire surface. In the illustrated example, the tip of the inner diameter side surface is formed as an inclined surface that slopes toward the radial center b2 of the tip 21b as it approaches the tip 21b. A recess 25 that opens toward the outer diameter side is provided on the outer diameter side surface of the base end 22 of the second seal portion 21A. This recess 25 is rectangular groove-shaped in a radial cross section, similar to the recess 17A of the first seal portion 13A. One side of the recess 25 in the groove width direction is defined by the second seal base 20, and the other side is defined by a groove wall 25b facing the second seal base 20, and the groove bottom is defined by a cylindrical groove bottom 25a that faces the outer diameter side. The groove bottom 25a is located so as to be substantially coincident with the radial center b2 of the tip 21b of the second seal portion 21A. In the illustrated example, the groove bottom 25a is located slightly radially outward of the radial center b2 of the tip 21b of the second seal portion 21A. The radial dimension of the base end 22 where the recess 25 of the second seal portion 21A is located is smaller than the radial dimension w2 of the entire second seal portion 21A. The gasket 10A configured as described above is easily elastically deformed so as to collapse toward the outer diameter side starting from the base ends 14, 22 when assembled to the first member 1 and the second member 5.

[0028] FIG. 4B schematically illustrates a gasket 10B according to a second modification. This gasket 10B differs from the above-described examples primarily in that a first seal portion 13B is provided via a first protruding base 18 that protrudes from the first seal base 12 toward the first member 1, and a second seal portion 21B is provided via a second protruding base 26 that protrudes from the second seal base 20 toward the second member 5. The first protruding base 18 is annularly shaped and protrudes from the inner end of the first seal base 12 toward the first member 1. The inner and outer corners of the first protruding base 18 relative to the first seal base 12 are concavely curved. The inner and outer side surfaces of the first protruding base 18 distal to the corners are generally cylindrical.

[0029] The first seal portion 13B is formed in an annular shape at the tip of the first protrusion 18 so as to protrude from the outer end toward the first member 1. The inner diameter side tip surface 19 of the first protrusion 18, which is continuous with the inner diameter side of the first seal portion 13B, is flat and parallel to the radial direction. In this modification, the radial dimension w1 of the first seal portion 13B is the dimension at the base end 13a, which is virtually flush with the tip surface 19. The dimension h1 of the first seal portion 13B along the opposing direction is the dimension from the base end 13a to the tip 13b of the first seal portion 13B in the protruding direction. In this modification, the first seal portion 13B is tapered almost entirely along the protruding direction. That is, the outer diameter side surface and the inner diameter side surface of the first seal portion 13B are formed as inclined surfaces that approach each other toward the tip 13b. As in the above example, the first seal portion 13B may also be configured such that the radial center of the tip end 13b is located radially outward of the radial center of the base end 13a.

[0030] The second protrusion 26 is formed in an annular shape so as to protrude from the outer diameter end of the second seal base 20 toward the second member 5. The inner diameter and outer diameter corners of the second protrusion 26 relative to the second seal base 20 are concavely curved. The inner diameter side and outer diameter side of the second protrusion 26 distal from the corners are cylindrical over substantially the entirety. The second seal portion 21B is formed in an annular shape so as to protrude from the outer diameter end at the distal end of the second protrusion 26 toward the second member 5. The inner diameter side distal end surface 27 of the second protrusion 26, which is continuous with the inner diameter side of the second seal portion 21B, is formed in a flat surface parallel to the radial direction, as described above. The radial dimension w2 of the second seal portion 21B is the dimension of the base end 21a, which is virtually flush with the distal end surface 27. The dimension h2 of the second seal portion 21B along the opposing direction is the dimension from the base end 21a to the tip 21b of the second seal portion 21B in the protruding direction. Similar to the first seal portion 13B, the second seal portion 21B is tapered over substantially the entire protruding direction. As in the example described above, the radial center of the tip 21b of the second seal portion 21B may be located radially outward of the radial center of the base end 21a.

[0031] The gasket 10B according to this modification is also formed so that the first seal portion 13B and the second seal portion 21B elastically deform so as to collapse toward the outer diameter when the two members are assembled. In this gasket 10B, the first protrusion 18 and the second protrusion 26 may be configured to undergo almost no compressive deformation when the two members are assembled. In other words, this gasket 10B is suitable for assembly to two members having a relatively large gap between the first member 1 and the second member 5.

[0032] FIGS. 5( a) and 5(b) schematically illustrate a gasket 10C according to a third modification. The gasket 10C according to this modification further includes an annular third seal portion 28 made of an elastic material, which is provided on the second member 5 (one of the first and second members 1 and 5) of the core body 11 and protrudes toward the second member 5 to abut against the second member 5. The third seal portion 28 elastically deforms to collapse toward the outer diameter when the two members are assembled. This configuration further improves sealing performance by including the third seal portion 28. As shown in FIG. 5(a), the gasket 10C includes the first seal portion 13 and second seal portion 21 similar to those of the examples shown in FIGS. 1 to 3, and the third seal portion 28 is provided on the inner diameter side of the second seal portion 21. The third seal portion 28 is formed in substantially the same shape as the second seal portion 21 in a radial cross-sectional view. The third seal portion 28 may have a different shape in a radial cross section from the second seal portion 21. The third seal portion 28 is provided so that its tip 28a is located on the outer diameter side of the tip 13b of the first seal portion 13. In other words, the third seal portion 28 is provided so that its tip 28a does not overlap with the tip 13b of the first seal portion 13 when viewed in the opposing direction.

[0033] As shown in FIG. 5( b), in this modified example, the second member 5A into which the gasket 10C is incorporated has a flow path 6A with a smaller diameter than the second member 5 described above. Accordingly, the inner peripheral end of the flange portion 7A, which connects to the open end of the flow path 6A, is positioned further inward than the flange portion 7A. The third seal portion 28 abuts against the inner diameter portion of the flange portion 7A to provide a seal. Thus, the gasket 10C of this modified example is suitable for sealing the second member 5A, which has a relatively large sealing area. When the gasket 10C is incorporated between the first member 1 and the second member 5A, the third seal portion 28 elastically deforms to collapse toward the outer diameter, similar to the first seal portion 13 and the second seal portion 21. The annular sealed portion 4, which the first seal portion 13 of the first member 1 abuts against, and the annular sealed portion 9, which the third seal portion 28 of the second member 5 abuts against, overlap each other when viewed in the opposing direction. Due to this configuration, stress tends to be concentrated locally on the two components (sealed portions 4, 9) more than in the above-mentioned gasket, but the concentration of stress locally on the two components is alleviated compared to a gasket in which the tips of the sealing portions on both sides of the core body overlap each other when viewed in the opposing direction.

[0034] 6( a) and 6(b) schematically illustrate a gasket 10D according to a fourth modification. Unlike the third modification, this modification of the gasket 10D includes a third seal portion 29 on the first member 1 side of the core 11, which is one of the first and second members 1 and 5. The third seal portion 29 is formed so as to protrude from the first seal base 12 toward the first member 1 on the outer diameter side of the first seal portion 13. The third seal portion 29 has substantially the same shape as the first seal portion 13 in a radial cross-sectional view. The third seal portion 29 may have a different shape from the first seal portion 13 in a radial cross-sectional view. The third seal portion 29 is formed so that its tip 29a is located radially inward relative to the tip 21b of the second seal portion 21. In other words, the third seal portion 29 is formed so that its tip 29a does not overlap the tip 21b of the second seal portion 21 when viewed in the opposing direction.

[0035] As shown in FIG. 6( b), in this modified example, the first member 1A into which the gasket 10D is incorporated has a flange portion 3A with an outer diameter substantially identical to that of the flange portion 7 of the second member 5, which is larger than that of the flange portion 3 of the first member 1 shown in FIGS. 1 and 3. The third seal portion 29 abuts against the outer diameter side of the flange portion 3A to provide a seal. Thus, the gasket 10D of this modified example is suitable for sealing the first member 1A, which has a relatively large sealing area. When the gasket 10D is incorporated between the first member 1A and the second member 5, the third seal portion 29 elastically deforms to collapse toward the outer diameter, similar to the first seal portion 13 and the second seal portion 21. The annular sealed portion 8, which the second seal portion 21 of the second member 5 abuts against, and the annular sealed portion 9A, which the third seal portion 29 of the first member 1A abuts against, overlap each other when viewed in the opposing direction. Even with this configuration, as with the third modified example described above, the concentration of stress locally on the two components is reduced compared to a gasket in which the tips of the sealing portions on both sides of the core body overlap each other when viewed in the opposing direction.

[0036] The different configurations described in the above embodiments may be modified, rearranged, or combined as needed. Furthermore, the components are not limited to the configurations described above. For example, each seal portion may have an inner diameter side surface and an outer diameter side surface that are tapered from the base end to the tip. Furthermore, the shape of the tip of each seal portion is not limited to a flat surface parallel to the radial direction, but may be an arc or triangle when viewed in radial cross section. Furthermore, a configuration including multiple seal portions may be used. Furthermore, the overall shape of the gasket is not limited to a circular ring shape as long as it is formed in a ring shape. Furthermore, the first and second components are not limited to tubular components, and may be components without a flow path.

[0037] 1, 1A First member 4 Sealed portion 5, 5A Second member 8 Sealed portion 11 Core body 10-10D Gasket 13-13B First seal portion 13a Base end 13b Tip 14 Base end 15, 16 Corner portion 17 Recessed portion 21-21B Second seal portion 21a Base end 21b Tip 22 Base end 23, 24 Corner portion 25 Recessed portion 28, 29 Third seal portion w1, w2 Dimension along the radial direction h1, h2 Dimension along the opposing direction a1, a2 Center in the radial direction at the base end b1, b2 Center in the radial direction at the tip in the protruding direction

Claims

1. An annular gasket that seals between two members, a first member and a second member, that are assembled opposite each other, comprising: a first annular seal portion made of an elastic material that is provided on the first member side of an annular core body and that protrudes toward the first member and abuts against the first member; and a second annular seal portion made of an elastic material that is provided on the second member side of the core body and that protrudes toward the second member and abuts against the second member, wherein the first seal portion and the second seal portion are arranged so as not to overlap each other when viewed in the opposing direction of the first member and the second member, and are formed so as to elastically deform so as to collapse toward the outer diameter when the two members are assembled.

2. A gasket according to claim 1, wherein at least one of the first seal portion and the second seal portion has a dimension along the radial direction that is smaller than a dimension along the opposing direction.

3. A gasket according to claim 1 or claim 2, characterized in that the center of the radial direction at the tip of at least one of the first seal portion and the second seal portion is located on the outer diameter side of the center of the radial direction at the base end on the core body side.

4. A gasket according to claim 1 or claim 2, characterized in that the base end of at least one of the first seal portion and the second seal portion has a smaller radius of curvature at the corner on the outer diameter side than at the corner on the inner diameter side when viewed in radial cross section.

5. A gasket according to claim 1 or claim 2, characterized in that a groove-shaped recess extending in the circumferential direction is provided on the outer diameter side surface of the base end of at least one of the first seal portion and the second seal portion.

6. A gasket according to claim 1 or claim 2, further comprising an annular third seal portion made of an elastic material that is provided on one of the first and second members of the core body, protrudes toward the one member, and abuts against the one member, and that is formed so as to elastically deform so as to collapse toward the outer diameter when the two members are assembled.

7. A sealing structure in which a gasket as described in claim 1 or claim 2 is assembled between two members, a first member and a second member, which are assembled opposite each other, wherein the annular sealed portion against which the first sealing portion provided on the first member abuts and the annular sealed portion against which the second sealing portion provided on the second member abuts do not overlap each other when viewed in the opposing direction.

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