Gasket and seal structure incorporated with the same

Abstract

To provide a gasket capable of improving seal performance, and a seal structure incorporated with the gasket.SOLUTION: An annular gasket 10 seals between two members, a first member 1 and a second member 5, which are assembled so as to face each other. The annular gasket comprises: an annular first seal part 13 made of an elastic material, which is provided on the first member side of an annular core 11, and protrudes toward the first member to be in contact with 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, and protrudes toward the second member to be in contact with the second member. The first seal part and the second seal part are arranged so as not to overlap each other when viewed in a direction in which the first member and the second member face each other, and are formed so as to elastically deform so as to collapse toward an outer diameter when the two members are assembled.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] BACKGROUND ART Gaskets that are provided with seal portions that come into contact with 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 adhere to a cylinder or cylinder head are provided on the front and back of a substrate made of a metal plate, and the center positions of each surface pressure agent are shifted from each other in the radial direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 2785955 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned Patent Document 1 discloses that the height of the surface pressure agent may be adjusted 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 part of the circumferential direction of the surface pressure agent may tilt 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. [Means for solving the problem]

[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 characterized in that it comprises: 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 will disclose that the gasket according to the present invention may have 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 dimension along the radial direction that is smaller than a dimension along 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 on the outer diameter side of the radial center at the base end that is on the core body side. <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 radius of curvature of a corner on the outer diameter side that is smaller than the radius of curvature of a corner on the inner diameter side when viewed in radial cross section. <Configuration 5> In any one of the first to fourth configurations, a groove-shaped recess extending in a circumferential direction may be 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. <Configuration 6> In any one of configurations 1 to 5, the core body may further include a ring-shaped third seal portion made of an elastic material that is provided on one of the first and second members, 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. [Effects of the Invention]

[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. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic vertical cross-sectional view showing a gasket according to an embodiment of the present invention and a seal structure to which the gasket is assembled. [Figure 2] 2A is a schematic plan view of the gasket, and FIG. 2B is a cross-sectional view taken along line XX in FIG. 2A. [Figure 3] FIG. 2 is a schematic vertical cross-sectional view of the gasket and the seal structure. [Figure 4] 10(a) and 10(b) are schematic longitudinal sectional views each showing a gasket according to a modified example of the embodiment. [Figure 5] 1A is a schematic vertical cross-sectional view showing a gasket according to a modified example of the embodiment, and FIG. 1B is a schematic vertical cross-sectional view of the gasket and a seal structure to which the gasket is assembled. [Figure 6]1A is a schematic vertical cross-sectional view showing a gasket according to a modified example of the embodiment, and FIG. 1B is a schematic vertical cross-sectional view of the gasket and a seal structure to which the gasket is assembled. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an example of a gasket according to an embodiment and a sealing structure to which the gasket is assembled will be described with reference to the drawings. Note that in some drawings, some of the detailed reference numerals used in other drawings are omitted. 1 to 6 are diagrams showing an example of a gasket according to the present embodiment, an example of a sealing structure to which the gasket is assembled, and modifications thereof.

[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 body 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 body 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 opposing direction of the first member 1 and the second member 5. 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 unlikely to overlap when viewed in the opposing direction, and stress concentration on localized areas of the two members is alleviated compared to a gasket in which the seal portions on both sides of the core overlap each other when viewed in the opposing direction. The first seal portion 13 and the second seal portion 21 are formed so as to elastically deform and tilt toward the outer diameter when assembled to the two components. With this configuration, the first seal portion 13 and the second seal portion 21 elastically deform and tilt toward the outer diameter when the two components are assembled. This prevents the first seal portion 13 and the second seal portion 21 from tilting in an unintended direction in the circumferential direction and twisting, thereby improving sealing performance. Furthermore, compared to a configuration in which the first seal portion 13 and the second seal portion 21 are formed so as to tilt toward the inner diameter and the seal position is reduced in diameter, the seal position is expanded when the two components are assembled. This makes it less likely for bending due to reduced diameter to occur and less likely for twisting to occur, thereby improving sealing performance. Furthermore, when the two components are tubular members 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 reduces the likelihood of impeding 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 in contact with the first seal portion 13 provided on the first member 1 side, and the annular sealed portion 8, which is in contact with 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 FIGS. 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 with a gasket 10 interposed between them. 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 portion 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 Fig. 1 and Fig. 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 a circular first seal base 12 made of an elastic material and fixed 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 end of the inner diameter side of the first seal base 12 toward the first member 1. The gasket 10 includes a second seal base 20 made of an elastic ring-shaped material that is fixed to the surface of the core body 11 that faces 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 20 toward the second member 5.

[0017] 2(b), the first seal portion 13 is formed so that the radial dimension thereof 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 13a and smallest at the tip end 13b. The first seal portion 13 has a radial dimension w1 (the dimension along the radial direction of the base end 13a, which is the largest portion) that is smaller than a dimension h1 along the facing direction (the protruding dimension). This configuration allows the first seal portion 13 to more easily 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 13a, which is virtually flush with the surface of the first seal base 12 facing the first component 1. The dimension h1 of the first seal portion 13 along the facing direction is the dimension from the base end 13a to the tip 13b of the first seal portion 13 in the protruding direction. The radial dimension w1 and the dimension h1 along the facing direction of the first seal portion 13 may be appropriately set so that the first seal portion 13 can more easily collapse toward the outer diameter.

[0018] The first seal portion 13 has a radial center b1 at the tip 13b in the protruding direction located closer to the outer diameter than a radial center a1 at the base end 13a on the core body 11 side. With this configuration, the first seal portion 13 can easily collapse from the tip 13b side toward the outer diameter side when the two members are assembled. As shown in Fig. 2(a), the tip 13b is formed in an annular shape when viewed in the opposing direction (in a plan view). The tip 13b is formed in a flat surface parallel to the radial direction. The base end 13a is also formed in an annular shape and is formed concentrically with the tip 13b. The first seal portion 13 is formed so that the imaginary circle formed by the radial center b1 of the tip end 13b is located on the outer diameter side when viewed in the opposing direction than the imaginary circle formed by the radial center a1 of the base end 13a.

[0019] In a radial cross section, the base end 14 of the first seal portion 13 is formed so 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 outer diameter side corner 16 of the first seal portion 13 tends to have a smaller cross-sectional area in a radial cross section 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 corner 15 on the inner diameter side of the base end 14 of the first seal portion 13 is formed into a concave curved surface that becomes more outer diameter side toward the first member 1 so as to have the above-mentioned radius of curvature. Also, the corner 16 on the outer diameter side of the base end 14 of the first seal portion 13 is formed into a concave curved surface that becomes more outer diameter side toward the second member 5. In other words, in a radial cross section, the corner 15 on the inner diameter side is formed into a more gentle concave curved surface than the corner 16 on the outer diameter side.

[0020] A groove-like recess 17 extending in the circumferential direction is provided on the outer diameter side surface of the base end 14 of the first seal portion 13. With this configuration, the recess 17 makes it easier for the first seal portion 13 to fall toward the outer diameter side when the two members are assembled. The recess 17 is provided to constitute a corner 16 on the outer diameter side of the base end 14 of the first seal portion 13. This 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. This recess 17 is formed into a concave curved surface such that the groove bottom and the groove walls on both sides thereof are continuous. This recess 17 is formed so as to be slightly recessed toward the inner diameter side from the outer diameter side surface that is continuous with the first member 1 side of this recess 17. The outer diameter side surface (outer peripheral surface) and inner diameter side surface (inner peripheral surface) of the first seal portion 13 at a midpoint in the protruding direction that connects to the first member 1 side of the base end portion 14 are cylindrical. The tip side portion of the first seal portion 13 that connects to the first member 1 side of the midpoint in the protruding direction is formed so that the radial dimension decreases toward the first member 1. The outer diameter side surface and inner diameter side surface of the tip side portion are formed as inclined surfaces that incline toward the radial center b1 of the tip 13b as they approach the tip 13b.

[0021] The second seal portion 21 is formed so that the radial dimension thereof 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 smallest at the tip end 21b. The dimension w2 along the radial direction of the base end 21a of this second seal portion 21 is larger than the dimension w1 along the radial direction 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 disposed below the first member 1, as shown in Fig. 3, the elastic deformation of the lower second seal portion 21 will be smaller than that of the first seal portion 13. Furthermore, since the second seal portion 21 is disposed on the outer diameter side of the first seal portion 13, the gasket 10 will be more likely to be maintained in a stable position.

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

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

[0024] As shown in Figures 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 Figure 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. On the other hand, 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 that abuts against the elastically deformed first seal portion 13 and the sealed portion 8 provided on the flange portion 7 of the second member 5 that abuts against 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 inner and outer diameter dimensions of the flange portions 3, 7 of the first member 1 and the second member 5 are different, 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, a gasket according to a modified example will be described with reference to FIGS. 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 operational effects as those of the previously described example will also be omitted or briefly explained.

[0026] FIG. 4(a) schematically shows a gasket 10A according to a first modified example. This gasket 10A differs from the above-described examples mainly in the configuration of the recessed portion 17A of the first seal portion 13A and in that a recessed portion 25 is provided in the second seal portion 21A. The first seal portion 13A has a cylindrical inner diameter side surface closer to the first member 1 than the inner diameter corner portion 15 over substantially the entire surface. The outer diameter side surface of the base end 14 of the first seal portion 13A has a recessed portion 17A recessed further inward than the above-described example. This recessed portion 17A has a rectangular groove shape in radial cross section. One side in the groove width direction is defined by the first seal base 12, the other side in the groove width direction 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 facing the outer diameter direction. This groove bottom 17a is positioned so as to approximately coincide with the radial center b1 of the tip end 13b of the first seal portion 13A. In the illustrated example, the groove bottom 17a is positioned slightly inward of the radial center b1 of the tip end 13b of the first seal portion 13A. The radial dimension of the base end 14 where the recess 17A of the first seal portion 13A is provided is smaller than the radial dimension w1 of the entire first seal portion 13A.

[0027] The second seal portion 21A is generally similar to the first seal portion 13A, and the inner diameter side surface on the second member 5 side from the inner diameter side corner portion 23 is cylindrical over almost the entire surface. In the illustrated example, the tip portion of the inner diameter side surface is formed as an inclined surface that slopes toward the tip 21b so as to become the radial center b2 of the tip 21b. The base end 22 of the second seal portion 21A has a recess 25 on its outer diameter side that opens toward the outer diameter. This recess 25 has a rectangular groove shape 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. The groove bottom 25a is defined by a cylindrical groove bottom 25a that faces the outer diameter. The groove bottom 25a is positioned so as to generally coincide with the radial center b2 of the tip 21b of the second seal portion 21A. In the illustrated example, the groove bottom 25a is positioned slightly toward the outer diameter side 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 provided is smaller than the radial dimension w2 of the entire second seal portion 21A. The gasket 10A having the above-described structure is easily elastically deformed so as to collapse toward the outer diameter side from the base ends 14, 22 when assembled to the first member 1 and the second member 5.

[0028] FIG. 4(b) schematically shows a gasket 10B according to a second modified example. This gasket 10B differs from the above-mentioned examples mainly in that a first seal portion 13B is provided via a first protrusion 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 protrusion 26 that protrudes from the second seal base 20 toward the second member 5. The first protrusion base 18 is formed in an annular shape so as to protrude from the inner diameter side end of the first seal base 12 toward the first member 1. The corners of this first protrusion base 18 on the inner diameter side and outer diameter side with the first seal base 12 are formed into concave curved surfaces. The inner diameter side surface and outer diameter side surface of the first protrusion base 18 on the tip side of the corners are formed into cylindrical surfaces over almost the entire surface.

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

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

[0031] In the gasket 10B according to this modification, the first seal portion 13B and the second seal portion 21B are also formed to 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 suitably assembled to two members in which the gap between the first member 1 and the second member 5 is relatively large.

[0032] 5(a) and (b) schematically show a gasket 10C according to a third modified example. The gasket 10C according to this modification is provided on the second member 5 side of the core body 11, which is one of the first member 1 and the second member 5, and further includes an annular third seal portion 28 made of an elastic material that protrudes toward the second member 5 and abuts against the second member 5. The third seal portion 28 elastically deforms so as to collapse toward the outer diameter side when the two members are assembled. With this configuration, the formation of the third seal portion 28 further improves sealing performance. 5(a), the gasket 10C includes a first seal portion 13 and a second seal portion 21 similar to those in the examples of FIGS. 1 to 3, and a 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 section. However, the third seal portion 28 may have a different shape from the second seal portion 21 in a radial cross section. 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 modification, the second member 5A into which the gasket 10C is incorporated has a flow path 6A with a smaller diameter than that of the second member 5. Accordingly, the inner peripheral end of the flange portion 7A, which is connected to the open end of the flow path 6A, is located further inward than the above-described flange portion 7A. The third seal portion 28 abuts against the inner diameter portion of the flange portion 7A to provide a seal. In this way, the gasket 10C of this modification is suitable for use in sealing a second member 5A having a relatively large sealing area. When gasket 10C is fitted 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 concentrate more locally on the two members (sealed portions 4, 9) than in the above-mentioned gasket, but the concentration of stress locally on the two members is alleviated compared to a gasket in which the tips of the seal portions on both sides of the core overlap each other when viewed in the opposing direction.

[0034] 6(a) and (b) schematically show a gasket 10D according to a fourth modified example. In this modified example, the gasket 10D differs from the third modified example described above in that a third seal portion 29 is provided on the first member 1 side, which is one of the first member 1 and second member 5 of the core body 11. 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 is formed in substantially the same shape as the first seal portion 13 in a radial cross section. Note that the third seal portion 29 may have a different shape from the first seal portion 13 in a radial cross section. The third seal portion 29 is provided 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 provided so that its tip 29a does not overlap with the tip 21b of the second seal portion 21 when viewed in the opposing direction.

[0035] As shown in Figure 6(b), in this modification, the first member 1A into which this gasket 10D is incorporated has a flange portion 3A whose outer diameter is approximately the same as that of the flange portion 7 of the second member 5, and which is larger than that of the flange portion 3 of the first member 1 shown in Figures 1 and 3. The third seal portion 29 abuts against the outer diameter side of this flange portion 3A to provide a seal. In this way, the gasket 10D of this modification is suitable for use in sealing a first member 1A having a relatively large sealing area. When gasket 10D is fitted between first member 1A and second member 5, third seal portion 29 elastically deforms to collapse radially outward, similar to first seal portion 13 and second seal portion 21. Annular sealed portion 8, which is in contact with second seal portion 21 of second member 5, and annular sealed portion 9A, which is in contact with third seal portion 29 of first member 1A, overlap each other when viewed in the opposing direction. Even with this configuration, as with the third modified example described above, localized stress concentration on the two members is alleviated compared to a gasket in which the tips of the seal portions on both sides of the core 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, the gasket may be configured to include multiple seal portions. Furthermore, the overall shape of the gasket is not limited to a circular ring shape, as long as it is formed in a circular shape. Furthermore, the first member and the second member are not limited to tubular members, and may be members that do not have a flow path. [Explanation of symbols]

[0037] 1,1A First member 4 Sealed part 5,5A Second member 8 Sealed part 11 Core body 10~10D gasket 13~13B First seal part 13a proximal end 13b tip 14 Proximal end 15,16 Corner 17 Recess 21~21B Second seal part 21a proximal end 21b tip 22 Proximal end 23,24 Corner 25 recess 28,29 Third seal section w1, w2 Radial dimensions h1, h2 Dimensions along the opposing direction a1, a2 Center along the radial direction at the base end b1, b2 Center along the radial direction at the tip of 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, a first annular seal portion made of an elastic material provided on the first member side of an annular core body, protruding toward the first member and abutting against the first member; and a second annular seal portion made of an elastic material provided on the second member side of the core body, protruding toward the second member and abutting against the second member, A gasket characterized in that the first sealing portion and the second sealing 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. In claim 1, A gasket, wherein at least one of the first seal portion and the second seal portion has a dimension along a radial direction that is smaller than a dimension along the opposing direction.

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

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

5. In claim 1 or claim 2, A gasket characterized in that a groove-shaped recess extending along a 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. In claim 1 or claim 2, a third annular seal portion made of an elastic material, which is provided on one of the first and second members of the core body, protruding toward the one member and coming into contact with the one member; A gasket characterized in that the third seal portion is formed so as to be elastically deformed so as to collapse toward the outer diameter side when the two members are assembled.

7. A seal structure in which the gasket according to claim 1 or 2 is assembled between two members, a first member and a second member, which are assembled opposite to each other, A sealing structure 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 with each other when viewed in the opposing direction.

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