washer

Abstract

A gasket is to be installed between a first shell and a second shell, and includes: a first annular portion in an annular shape; a second annular portion in an annular shape, the second annular portion being positioned radially inward of the first annular portion, and having a first gap between the first annular portion and the second annular portion; and a first connecting portion, the first connecting portion connecting the first annular portion and the second annular portion in a portion of the first gap.

Description

Technical Field

[0001] The invention relates to a gasket. Background Art

[0002] Various types of gaskets have been proposed for installation between a pair of housings. For example, Patent Document 1 discloses a gasket in which a flange portion is formed along its inner periphery and protrudes toward one of the housings. In addition, Patent Document 2 discloses a gasket in which a bent portion is formed along its outer peripheral edge and tilted downward.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-36607

[0006] Patent Document 2: Japanese Patent Application Publication No. 2013-61002 Summary of the invention

[0007] Problems to be solved by the present invention

[0008] When corrosion occurs on the contact surface between the housing and the gasket, a small gap is formed between the housing and the gasket (i.e., on the sealing surface) due to corrosion, thereby reducing the sealing ability. Therefore, liquid may penetrate from the outside of the housing into the portion where corrosion occurs at the sealing surface of the housing and the gasket, and penetrate into the housing. In view of the above, an object of the present invention is to enhance the sealing ability by reducing the penetration of liquid toward the inside of the housing.

[0009] Means of solving the problem

[0010] In order to solve the above-mentioned problem, a gasket according to one aspect (first aspect) of the present invention is a gasket to be installed between a first housing and a second housing. The gasket includes: a first annular portion in an annular shape; a second annular portion in an annular shape, the second annular portion being located at the radial inner side of the first annular portion, and having a first gap between the first annular portion and the second annular portion; and a first connecting portion, the first connecting portion connecting the first annular portion and the second annular portion in a part of the first gap. In this aspect, a first gap extending in a circumferential direction is formed between the first annular portion and the second annular portion. After reaching the first gap between the first annular portion and the second annular portion, the liquid that penetrates from the outside of the housing into the housing and the first annular portion penetrates in the circumferential direction along the first gap. Therefore, the penetration of the liquid in the radial direction is reduced. Therefore, compared with a structure in which the first gap is not formed, the penetration of the liquid into the housing can be reduced. In other words, despite corrosion at the sealing surface of the housing, the sealing ability can be enhanced (and the sealing ability can be maintained for a long time).

[0011] "Loop-shaped" refers to a shape formed by a straight line surrounding a space in a loop or a curve surrounding a space in a loop. The plane shape of the "loop portion" (also referred to as an "annular portion") can be freely selected. For example, each of the plane shapes of the first loop portion and the second loop portion may be circular or polygonal (e.g., rectangular).

[0012] In addition, in the first aspect, the first annular portion and the second annular portion are specified. However, the scope of the first aspect obviously includes a configuration having annular portions other than the first annular portion and the second annular portion. In other words, the first annular portion and the second annular portion refer to two annular portions adjacent to each other in the radial direction among the multiple annular portions contained in the gasket. The number of annular portions constituting the gasket can be freely selected. The first annular portion is not limited to the outermost annular portion among the multiple annular portions, and the second annular portion is not limited to the innermost annular portion among the multiple annular portions.

[0013] In a preferred example of the first aspect (the second aspect), the first connection portion is thinner than both the first annular portion and the second annular portion. In the above configuration, a recess is formed due to a stepped portion between the surface of the first annular portion or the surface of the second annular portion and the surface of the first connection portion. In other words, in a state where the gasket is installed between the first housing and the second housing, the first gap is extended in the circumferential direction via the recess. In the above configuration, the liquid flows between a portion of the first gap located on one side of the first connection portion in the circumferential direction and a portion of the first gap located on the other side of the first connection portion in the circumferential direction. Therefore, a volume sufficient to accumulate liquid is ensured in the first gap. Therefore, compared with a configuration in which the first connection portion is as thick as each of the first annular portion and the second annular portion, liquid penetration into the housing can be reduced. Each thickness of the first connection portion, the first annular portion and the second annular portion includes a dimension in a direction parallel to the central axis of the gasket.

[0014] The gasket in the preferred example (third aspect) of the second aspect includes a plate-like base portion made of metal and an elastic layer partially covering the base portion. Each of the first annular portion and the second annular portion is a portion including the base portion and the elastic layer, and the first connecting portion is a portion including the base portion but not including the elastic layer. In the above-mentioned configuration, since the elastic layer is elastically deformed by contact with the housing, the sealing ability can be improved. In addition, the following advantage is obtained: the recess corresponding to the first connecting portion is formed by a simple configuration in which the elastic layer is not formed on the portion of the base portion corresponding to the first connecting portion.

[0015] In a preferred example of the first aspect (the fourth aspect), the first connection portion is as thick as each of the first annular portion and the second annular portion. In the above configuration, since the first connection portion is as thick as each of the first annular portion and the second annular portion, the manufacturing cost is lower than that of the configuration in which the first connection portion is thinner than each of the first annular portion and the second annular portion.

[0016] In a preferred example of the fourth aspect (fifth aspect), the first annular portion, the second annular portion and the first connecting portion respectively include a plate-like base portion made of metal and an elastic layer covering the base portion. In the above configuration, in addition to the first annular portion and the second annular portion, the first connecting portion is also composed of a stack of base portions and elastic layers. Therefore, the first annular portion, the second annular portion and the first connecting portion have the same cross-sectional structure. Therefore, compared with a configuration in which the cross-sectional structure of the first connecting portion is different from the cross-sectional structure of the first annular portion or the second annular portion, the advantage of lower manufacturing cost is obtained.

[0017] The gasket according to any one of the preferred examples of the first to fifth aspects (the sixth aspect) includes: a third annular portion in an annular shape, the third annular portion being arranged at the radial inner side of the second annular portion, and having a second gap between the second annular portion and the third annular portion; and a second connecting portion, the second connecting portion connecting the second annular portion and the third annular portion in a part of the second gap. In the above-mentioned configuration, according to this aspect, a first gap and a second gap are formed between the first annular portion and the third annular portion, and the first gap and the second gap extend in the circumferential direction, respectively. Therefore, the following effect is particularly significant: the penetration of liquid into the shell can be reduced.

[0018] In a preferred example of the sixth aspect (the seventh aspect), the first connection part and the second connection part are located at the same position in the circumferential direction. In addition, in another preferred example of the sixth aspect (the eighth aspect), the first connection part and the second connection part are located at different positions in the circumferential direction. In this aspect, since the first connection part and the second connection part are located at different positions in the circumferential direction, the liquid that penetrates along the first connection part needs to move in the circumferential direction until it reaches the second connection part. Therefore, compared with the structure in which the first connection part and the second connection part are located at the same position in the circumferential direction, it takes longer for the liquid to reach the inside of the third annular part. Therefore, it is possible to reduce the penetration of liquid into the shell for a long time. In a structure in which the first connection part is as thick as each of the first annular part and the second annular part, when the first connection part and the second connection part are located at the same position in the circumferential direction, the liquid that penetrates from the outside of the shell is easy to penetrate from the first connection part to the second connection part continuously in the radial direction. Therefore, the eighth aspect is particularly effective in a structure in which the first connection part is as thick as each of the first annular part and the second annular part.

[0019] In a preferred example (ninth aspect) of any one of the sixth to eighth aspects, the width of the first gap is different from the width of the second gap. In an exemplary aspect (tenth aspect), the width of the second gap is greater than the width of the first gap. According to the present invention, it is possible to ensure that the time period from the time point when the liquid begins to penetrate the first gap or the wider second gap to the time point when the liquid fills the wider gap is sufficient. Therefore, it is possible to reduce the penetration of liquid into the housing over a long period of time.

[0020] In a preferred example (the eleventh aspect) of any one of the first to tenth aspects, a through hole is formed in the first annular portion, a fastener is inserted into the through hole, the fastener connects the first shell and the second shell, and the first connecting portion is formed near the through hole. Near the fastener, the first shell and the second shell are fastened to each other by the fastener, thereby fully compressing the gasket. In other words, there is a tendency that the liquid hardly penetrates into the vicinity of the through hole in the gasket compared to other parts of the gasket. On the other hand, the liquid that penetrates the space between the shell and the gasket can penetrate in the radial direction along the first connecting portion. Therefore, according to the configuration in which the first connecting portion is installed near the through hole, the penetration of the liquid via the first connecting portion can be effectively reduced.

[0021] The gasket according to the preferred example (twelfth aspect) of any one of the first to tenth aspects further includes a third connection portion, the third connection portion connecting the first annular portion and the second annular portion in a portion of the first gap, wherein the space between the first connection portion and the third connection portion is a through hole inserted with a fastener, and the fastener connects the first shell and the second shell. Compared with other parts of the gasket, there is a tendency that liquid hardly penetrates into the portion near the through hole in the gasket. Therefore, according to the eleventh aspect, the possibility that liquid will penetrate into the shell from the vicinity of the first connection portion and the third connection portion is reduced. In addition, in the preferred aspect (thirteenth aspect), the first connection portion and the third connection portion are positioned at the inner side of the peripheral edge of the supporting surface of the fastener in a plan view. According to the above aspect, the following effect is particularly significant: it is possible to reduce the penetration of liquid into the shell from the vicinity of the first connection portion and the third connection portion.

[0022] In a preferred example (the fourteenth aspect) of any one of the first to thirteenth aspects, a protrusion is formed, which protrudes toward the first shell on a surface of at least one of the first annular portion or the second annular portion, the surface facing the first shell. In this aspect, since the protrusion in at least one of the first annular portion and the second annular portion contacts the first shell, the penetration of liquid from between the first shell and the gasket can be reduced.

[0023] In a preferred example (fifteenth aspect) of any one of the first to thirteenth aspects, a first protrusion is formed on a facing surface of the first annular portion facing the first shell, and the first protrusion is formed on a facing surface of the second annular portion facing the first shell, and the second protrusion is formed on a facing surface of the second annular portion facing the first shell, and the second protrusion is formed on the facing surface of the second annular portion facing the first shell, and the second protrusion is formed on the first shell. According to this aspect, since the first protrusion and the second protrusion are in contact with the first shell, the penetration of liquid from between the first shell and the gasket can be effectively reduced.

[0024] In a preferred example (the sixteenth aspect) of any one of the first to thirteenth aspects, a first protrusion protruding toward the first shell along the shape of the first annular portion is formed on the facing surface of the first annular portion facing the first shell, and a second protrusion protruding toward the second shell along the shape of the second annular portion is formed on the facing surface of the second annular portion facing the second shell. According to this aspect, the penetration of liquid from the space between the first shell or the second shell and the gasket can be reduced. In addition, since the first protrusion and the second protrusion protrude in opposite directions respectively, the following effect is obtained: the warping in the gasket can be reduced.

[0025] In a preferred example (the seventeenth aspect) of any one of the first to sixteenth aspects, a hydrophilic film is formed on the inner peripheral surface of at least one of the first annular portion or the second annular portion, and the hydrophilic film covers the inner peripheral surface. According to this aspect, since the hydrophilic film promotes the penetration of the liquid that has reached the inside of the first gap along the inner peripheral surface of the first annular portion, the penetration of the liquid into the housing can be delayed.

[0026] The gasket according to a preferred aspect (the eighteenth aspect) of the present invention is an annular gasket installed between a first housing and a second housing, wherein an annular protrusion is formed in the gasket, the protrusion protrudes toward the first housing or the second housing along the inner peripheral edge of the gasket, and a gap is formed between the protrusion and the outer peripheral edge along the outer peripheral edge of the gasket.

[0027] Effects of the Invention

[0028] According to an aspect of the present invention, the penetration of liquid toward the inside of the housing can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] [ Figure 1 ] is a sectional view showing the configuration of the sealing structure according to the first embodiment.

[0030] [ Figure 2 ] is a plan view showing a gasket according to the first embodiment.

[0031] [ Figure 3 ] is an explanatory diagram showing a state in which liquid penetrates toward the interior of the shell.

[0032] [ Figure 4 ] is along Figure 2 Cross-sectional view along line aa in FIG.

[0033] [ Figure 5 ] is along Figure 2 Cross-sectional view along line bb in FIG.

[0034] [ Figure 6 ] is a plan view showing a gasket according to a second embodiment.

[0035] [ Figure 7 ] is along Figure 6 Cross-sectional view along line cc.

[0036] [ Figure 8 ] is along Figure 6 Cross-sectional view along line dd.

[0037] [ Fig. 9 ] is a plan view showing a gasket according to a third embodiment.

[0038] [ Fig.10 ] is a plan view showing a gasket according to a fourth embodiment.

[0039] [ Fig.11 ] is a plan view showing a gasket according to a fifth embodiment.

[0040] [ Fig.12 ] is along Fig.11 Cross-sectional view along line ee.

[0041] [ Fig.13 ] is a plan view of a gasket according to a sixth embodiment.

[0042] [ Fig.14 ] is a plan view showing a gasket according to a modification of the sixth embodiment.

[0043] [ Fig.15 ] is a plan view showing a gasket according to a modification of the sixth embodiment.

[0044] [ Fig.16 ] is a plan view showing a gasket according to a seventh embodiment.

[0045] [ Fig.17 ] is along Fig.16 Cross-sectional view along line ff.

[0046] [ Fig.18 ] is along Fig.16 Cross-sectional view along line gg.

[0047] [ Fig.19] is a cross-sectional view showing the gasket in use.

[0048] [ Fig. 20 ] is a sectional view showing a gasket according to an eighth embodiment.

[0049] [ Fig.21 ] is a cross-sectional view showing the gasket in use.

[0050] [ Fig. 22 ] is a sectional view showing a gasket according to a ninth embodiment.

[0051] [ Fig.23 ] is a cross-sectional view showing the gasket in use.

[0052] [ Fig.24 ] is a sectional view showing a gasket according to a tenth embodiment.

[0053] [ Fig.25 ] is a cross-sectional view showing the gasket in use.

[0054] [ Fig.26 ] is a plan view showing a gasket according to an eleventh embodiment.

[0055] [ Fig. 27 ] is a partial perspective view showing a gasket according to a twelfth embodiment. DETAILED DESCRIPTION

[0056] [First embodiment]

[0057] Figure 1 1 is a cross-sectional view showing the configuration of the sealing structure 100 according to the first embodiment. The sealing structure 100 according to the first embodiment is installed in a vehicle such as a motor vehicle. The sealing structure 100 accommodates various types of electronic components for controlling the movement of the vehicle. Figure 1 As shown in , the sealing structure 100 according to the first embodiment includes a first housing 10 a , a second housing 10 b , a plurality of fasteners 12 , and a gasket 20 .

[0058] The first housing 10a is a hollow structure including an end surface E1 having an opening. Similarly, the second housing 10b is a hollow structure including an end surface E2 having an opening. The first housing 10a and the second housing 10b are respectively formed of an alloy including a metal such as aluminum or iron. The first housing 10a and the second housing 10b are fixed to each other by a plurality of fasteners 12 (e.g., bolts).

[0059] The gasket 20 is an annular sealing member installed between the first shell 10a and the second shell 10b. Specifically, the gasket 20 is arranged between the end face E1 of the first shell 10a and the end face E2 of the second shell 10b. In other words, the surface of the gasket 20 facing the first shell 10a contacts the end face E1, and the surface of the gasket 20 facing the second shell 10b contacts the end face E2. According to the above configuration, the gasket 20 seals the gap between the end face E1 of the first shell 10a and the end face E2 of the second shell 10b. The internal space of the first shell 10a and the internal space of the second shell 10b are connected to each other via the opening in the gasket 20.

[0060] Figure 2 2 is a plan view showing the gasket 20. Figure 2 As shown in , the gasket 20 includes a first annular portion P1, a second annular portion P2, a third annular portion P3, a plurality of first connecting portions C1, and a plurality of second connecting portions C2. In the following description, the "radial direction" indicates the direction of the radius of a circle centered on the central axis O of the gasket 20 in a plane perpendicular to the central axis O, and the "circumferential direction" indicates the direction of the outer circumference of the circle. In addition, the "plan view" indicates that the gasket 20 is observed from a direction parallel to the central axis O of the gasket 20.

[0061] Each of the first annular portion P1, the second annular portion P2, and the third annular portion P3 is an annular portion formed in a circular shape in a plan view. The thicknesses (i.e., the dimensions in the direction of the center axis O) of the first annular portion P1, the second annular portion P2, and the third annular portion P3 are the same as each other. In addition, the widths (i.e., the dimensions in the radial direction) of the first annular portion P1, the second annular portion P2, and the third annular portion P3 are the same as each other. The thicknesses or widths of the first annular portion P1, the second annular portion P2, and the third annular portion P3 may be different from each other as long as the desired sealing capability is maintained.

[0062] Depend on Figure 2 It can be seen that the outer diameter of the second annular portion P2 is smaller than the inner diameter of the first annular portion P1, and the outer diameter of the third annular portion P3 is smaller than the inner diameter of the second annular portion P2. The first annular portion P1, the second annular portion P2 and the third annular portion P3 are concentrically arranged in a common plane. Therefore, the second annular portion P2 is radially positioned at the inner side of the first annular portion P1, and the third annular portion P3 is radially positioned at the inner side of the second annular portion P2. In other words, the second annular portion P2 surrounds the third annular portion P3, and the first annular portion P1 surrounds the second annular portion P2.

[0063] The first gap D1 is formed between the first annular portion P1 and the second annular portion P2. In other words, the inner circumferential surface of the first annular portion P1 faces the outer circumferential surface of the second annular portion P2, and there is a first gap D1 between the inner circumferential surface of the first annular portion and the outer circumferential surface of the second annular portion. The first gap D1 is a gap (slit) extending in the circumferential direction. Similarly, the second gap D2 is formed between the second annular portion P2 and the third annular portion P3. Therefore, the inner circumferential surface of the second annular portion P2 is opposite to the outer circumferential surface of the third annular portion P3 in a manner separated by the second gap D2. The second gap D2 is a gap extending in the circumferential direction. In the first embodiment, the width W1 of the first gap D1 is the same as the width W2 of the second gap D2 (W1=W2). For example, each of the width W1 of the first gap D1 and the width W2 of the second gap D2 has an appropriate value in the range of, for example, 0.1 mm to 10 mm (including the end value). The width W1 is the size of the first gap D1 in the radial direction, and the width W2 is the size of the second gap D2 in the radial direction.

[0064] Each of the plurality of (for example, two) first connection portions C1 connects the first annular portion P1 and the second annular portion P2 in a portion of the first gap D1. Specifically, each of the first connection portions C1 extends from the inner circumferential surface of the first annular portion P1 to the outer circumferential surface of the second annular portion P2 in a radial direction. The two first connection portions C1 are respectively positioned on opposite sides relative to the central axis O of the gasket 20. Each of the plurality of (for example, two) second connection portions C2 connects the second annular portion P2 and the third annular portion P3 in a portion of the second gap D2. Specifically, each of the second connection portions C2 extends from the inner circumferential surface of the second annular portion P2 to the outer circumferential surface of the third annular portion P3 in a radial direction. The two second connection portions C2 are respectively positioned on opposite sides relative to the central axis O of the gasket 20.

[0065] like Figure 2 As shown in , the position of one first connection portion C1 in the circumferential direction is the same as the position of one second connection portion C2 in the circumferential direction. In other words, the position of the first connection portion C1 in the direction along the shape of the gasket 20 is the same as the position of the second connection portion C2 in the direction along the shape of the gasket 20. Specifically, both the first connection portion C1 and the second connection portion C2 are positioned on a straight line L orthogonal to the central axis O of the gasket 20. In other words, in a plan view, the first connection portion C1 is positioned between the second connection portion C2 and the first annular portion P1. The first connection portion C1 and the second connection portion C2 can be installed at different positions in the circumferential direction.

[0066] The following possibility is assumed: the liquid attached to the outer surface of the sealing structure 100 penetrates the sealing structure 100 from between the first shell 10a and the second shell 10b. For example, when the sealing structure 100 is used in a coastal environment, salt water may adhere to the sealing structure 100. In addition, when the sealing structure 100 is used in a cold environment, an aqueous solution of a deicing agent (such as calcium chloride) may adhere to the sealing structure 100. Figure 3 1 is an explanatory diagram showing a state where liquid penetrates into the sealing structure 100. Since the gasket 20 is in surface contact with the end surface E (end surface E1 or end surface E2) of the housing 10 (first housing 10a or second housing 10b), the liquid does not substantially penetrate into the internal space of the sealing structure 100. However, in a state where fine irregular concavoconvexities are formed on the end surface E due to corrosion caused by the adhesion of liquid such as salt water, the sealing ability of the gasket 20 is reduced. Therefore, as shown by Figure 3 As shown by arrow A1 in FIG. 1 , liquid may penetrate from the outside of the sealing structure 100 into between the end surface E of the housing 10 and the first annular portion P1 of the gasket 20 .

[0067] If Figure 3 As shown by the middle arrow A2, when the liquid that penetrates into the gap between the end face E and the first annular portion P1 reaches the first gap D1, due to the wettability of the liquid, the liquid penetrates in the circumferential direction along the first gap D1 (the contact line between the inner circumferential surface of the first annular portion P1 and the end face E). In other words, it is possible to suppress the liquid from penetrating radially inward. Therefore, compared with a structure in which the first gap D1 is not formed, the penetration of the liquid toward the inside of the housing 10 can be reduced. As described above, according to the first embodiment, since the penetration of the liquid toward the inside of the housing 10 is delayed, the penetration of the liquid into the sealing structure 100 can be reduced for a long time. In other words, compared with a structure in which the first gap D1 is not formed, the sealing ability of the gasket 20 can be enhanced even when the sealing surface of the housing 10 (i.e., the end face E1 and the end face E2) is corroded.

[0068] Once the liquid fills the first gap D1, as indicated by Figure 3 As shown by arrow A3 in FIG. 1 , liquid can penetrate the gap between the end surface E of the housing 10 and the second annular portion P2 of the gasket 20. Figure 3As shown by the middle arrow A4, when the liquid that penetrates into the gap between the end face E and the second annular portion P2 reaches the second gap D2, due to the wettability of the liquid, the liquid penetrates in the circumferential direction along the second gap D2 (the contact line between the inner circumferential surface of the second annular portion P2 and the end face E). In other words, the penetration of the liquid toward the radial inside is suppressed. Therefore, compared with the structure in which the second gap D2 is not formed, the penetration of the liquid toward the inside of the housing 10 can be suppressed. It can be understood from the above description that in the first embodiment, the state in which the liquid penetrates in the circumferential direction and the state in which the liquid penetrates forward in the radial direction toward the inside are repeated many times. Therefore, the above effect is particularly significant: the penetration of the liquid into the sealing structure 100 can be reduced for a long time.

[0069] The cross-sectional structure of the gasket 20 shown above will now be described. Figure 4 It is along Figure 2 The cross-sectional view of line aa in Figure 5 It is along Figure 2 The cross-sectional view of line bb in FIG. Figure 4 and Figure 5 As shown in FIG. 1 , the gasket 20 according to the first embodiment includes a base portion 21, a first elastic layer 22, and a second elastic layer 23 in a cross-sectional view. In the following description, when there is no need to particularly distinguish the first annular portion P1, the second annular portion P2, and the third annular portion P3, they are collectively referred to as "annular portion P". Similarly, when there is no need to particularly distinguish the first connecting portion C1 and the second connecting portion C2, they are collectively referred to as "connecting portion C".

[0070] The base portion 21 is a plate-shaped hard portion including a first face F1 and a second face F2. For example, the base portion 21 is made of metal. The first face F1 and the second face F2 are surfaces on opposite sides of the base portion 21 along the direction of the central axis O. The base portion 21 is made of, for example, a stainless steel plate, a cold-rolled steel plate, a galvanized steel plate, or an aluminum plywood.

[0071] The first elastic layer 22 is an elastic film that partially covers the first face F1 of the base portion 21. Similarly, the second elastic layer 23 is an elastic film that partially covers the second face F2 of the base portion 21. For example, the first elastic layer 22 is bonded to the first face F1 that has been subjected to a surface treatment (such as a lead phosphate coating treatment) by an adhesive. Similarly, the second elastic layer 23 is bonded to the second face F2 that has been subjected to a surface treatment (such as a lead phosphate coating treatment) by an adhesive. The surface of the first elastic layer 22 is in surface contact with the end face E1 of the first shell 10a, and the surface of the second elastic layer 23 is in surface contact with the end face E2 of the second shell 10b. The first elastic layer 22 and the second elastic layer 23 are examples of "elastic layers".

[0072] The first elastic layer 22 and the second elastic layer 23 are made of a freely selected elastic material. Specifically, it is preferable to use a synthetic rubber sheet (e.g., foam rubber) containing at least one type selected from, for example, nitrile rubber, styrene-butadiene rubber, fluororubber, acrylic rubber, and silicone rubber as the first elastic layer 22 and the second elastic layer 23. According to the above configuration, the sealing function of the gasket 20 can be improved by the contact of the first elastic layer 22 with the first shell 10a and the contact of the second elastic layer 23 with the second shell 10b.

[0073] like Figure 4 and Figure 5 As shown in FIG. 1 , each annular portion P (P1, P2, P3) is a portion of a stack including a base portion 21, a first elastic layer 22, and a second elastic layer 23. Figure 5 As shown in , each connection part C (C1, C2) is a part including the base part 21. The first elastic layer 22 and the second elastic layer 23 are not formed in each connection part C. In other words, in the first connection part C1, the first face F1 of the base part 21 is exposed to the first elastic layer 22, and the second face F2 of the base part 21 is exposed to the second elastic layer 23. As can be understood from the above description, the base part 21 is formed into a plane shape corresponding to the first annular part P1, the second annular part P2, the third annular part P3, each first connection part C1, and each second connection part C2. On the other hand, each of the first elastic layer 22 and the second elastic layer 23 is formed into a plane shape corresponding to the corresponding shape of the first annular part P1, the second annular part P2, and the third annular part P3. In other words, the first elastic layer 22 or the second elastic layer 23 does not include a portion corresponding to the first connection part C1 and the second connection part C2. As can be understood from the above description, each connection part C is thinner than each annular part P. Therefore, the thickness of each connection portion C corresponds only to the thickness of the base portion 21 , while the thickness of each annular portion P corresponds to the sum of the thicknesses of the base portion 21 , the first elastic layer 22 , and the second elastic layer 23 .

[0074] The gasket 20 having the above-described configuration is manufactured by bonding the surface of the base portion 21 to the first elastic layer 22 and the second elastic layer 23, each of which has a planar shape corresponding to each annular portion P, wherein the base portion 21 is formed into a planar shape corresponding to each annular portion P and each connecting portion C. In other words, in the first embodiment, the surface of the base portion 21 is formed to be covered with the elastic material (the first elastic layer 22 and the second elastic layer 23).

[0075] like Figure 5As shown in , a first recess R1 corresponding to the stepped portion is formed between the first face F1 of the base portion 21 and the surface of the first elastic layer 22 in the first connection portion C1 or the second connection portion C2. Similarly, a second recess R2 corresponding to the stepped portion is formed between the second face F2 of the base portion 21 and the surface of the second elastic layer 23 in the first connection portion C1 or the second connection portion C2. Therefore, in a state where the gasket 20 is mounted between the first shell 10a and the second shell 10b, the first gap D1 extends over the entire circumference of the gasket 20 through the first recess R1 and the second recess R2 corresponding to the first connection portion C1. Similarly, in a state where the gasket 20 is mounted between the first shell 10a and the second shell 10b, the second gap D2 extends over the entire circumference of the gasket 20 through the first recess R1 and the second recess R2 corresponding to the second connection portion C2. In the first embodiment, the first recessed portion R1 and the second recessed portion R2 may be formed by a simple configuration in which the first elastic layer 22 and the second elastic layer 23 are not formed in the first connection portion C1.

[0076] In the above structure, if Figure 3 As shown by arrow A1 in , the liquid reaching the first gap D1 flows through the first recess R1, that is, the gap between a portion of the first gap D1 located on one side of the first connection portion C1 along the circumferential direction and a portion of the first gap D1 located on the other side of the first connection portion C1 along the circumferential direction. Figure 3 As shown by arrow A3 in , the liquid reaching the second gap D2 flows through the second recess R2, that is, the gap between a portion of the second gap D2 located on one side of the second connection portion C2 along the circumferential direction and a portion of the second gap D2 located on the other side of the second connection portion C2 along the circumferential direction. It can be understood from the above description that according to the first embodiment, compared with the structure in which the first recess R1 and the second recess R2 are not formed, it is possible to ensure a volume sufficient to accumulate the liquid in the first gap D1 and the second gap D2. Therefore, the above effect is particularly significant: the penetration of liquid into the sealing structure 100 can be reduced over a long period of time.

[0077] [Second embodiment]

[0078] In each embodiment described below, for elements having substantially the same functions as those of the first embodiment, the reference numerals used in the description of the first embodiment are used, and detailed explanation of these elements is appropriately omitted.

[0079] Figure 6 2 is a plan view showing a gasket 20 according to a second embodiment. Figure 6As shown in, as in the first embodiment, the gasket 20 according to the second embodiment includes a first annular portion P1, a second annular portion P2, a third annular portion P3, a plurality of first connecting portions C1 and a plurality of second connecting portions C2. The relationship between the various elements is substantially the same as that of the various elements of the first embodiment. In other words, the second annular portion P2 is positioned at the radial inner side of the first annular portion P1 in a manner separated by a first gap D1, and the third annular portion P3 is positioned at the radial inner side of the second annular portion P2 in a manner separated by a second gap D2. In addition, each first connecting portion C1 connects the first annular portion P1 and the second annular portion P2 in a portion of the first gap D1, and each second connecting portion C2 connects the second annular portion P2 and the third annular portion P3 in a portion of the second gap D2. As described above, also in the second embodiment, the first gap D1 and the second gap D2 delay the penetration of the liquid. Therefore, as in the first embodiment, the following advantages are obtained: the penetration of liquid into the sealing structure 100 can be reduced.

[0080] The first embodiment describes a configuration in which the first connection portion C1 and the second connection portion C2 are located at the same position in the circumferential direction. Figure 6 As shown in , the position of the first connection portion C1 in the circumferential direction (or the position in the direction of the shape of the gasket 20) is different from the position of the second connection portion C2 in the circumferential direction. Specifically, each first connection portion C1 is positioned on a straight line L1 orthogonal to the central axis O of the gasket 20, and each second connection portion C2 is positioned on a straight line L2 orthogonal to the central axis O of the gasket 20. The straight line L1 and the straight line L2 intersect (for example, are orthogonal to each other). In other words, the first connection portion C1 is not located on the straight line L2, and the second connection portion C2 is not located on the straight line L2. In other words, the first connection portion C1 is not located between the second connection portion C2 and the first annular portion P1.

[0081] Figure 7 It is along Figure 6 The cross-sectional view of line cc in Figure 8 It is along Figure 6 A cross-sectional view of line dd in FIG. Figure 7 and Figure 8As shown in , in the second embodiment, in addition to the first annular portion P1, the second annular portion P2, and the third annular portion P3, the first connecting portion C1 and the second connecting portion C2 are also composed of a stack of the base portion 21, the first elastic layer 22, and the second elastic layer 23. In other words, the cross-sectional structure of each connecting portion C is the same as the cross-sectional structure of each annular portion P. Therefore, each connecting portion C has the same thickness as that of each annular portion P. As described above, in the second embodiment, since each annular portion P and each connecting portion C have the same structure, an advantage of reduced manufacturing cost is obtained compared to a configuration in which the connecting portion C and the annular portion P have different structures (for example, as in the first embodiment).

[0082] The gasket 20 according to the second embodiment is manufactured by partially punching a plate-like portion covered with an elastic film over the entire area of ​​both the first face F1 and the second face F2 by, for example, press working (i.e., by removing an area other than a portion forming the gasket 20). In other words, the base portion 21, the first elastic layer 22, and the second elastic layer 23 are formed together. In the second embodiment, the base portion 21 is formed after the elastic film as the first elastic layer 22 and the second elastic layer 23 is formed, whereas in the first embodiment, the first elastic layer 22 and the second elastic layer 23 are mounted after the base portion 21 is formed.

[0083] In the configuration in which the thickness of the connection portion C is the same as that of the annular portion P, when the position of the first connection portion C1 in the circumferential direction is the same as that of the second connection portion C2 in the circumferential direction, the liquid that penetrates from the outside of the sealing structure 100 easily penetrates continuously along the first connection portion C1, the second annular portion P2, and the second connection portion C2 in the radial direction forward toward the inside. In the second embodiment, although the connection portion C is as thick as the annular portion P, the position of the first connection portion C1 in the circumferential direction is different from the position of the second connection portion C2 in the circumferential direction. Therefore, the liquid that penetrates in the radial direction along the first connection portion C1 needs to flow in the circumferential direction until the liquid reaches the second connection portion C2. In other words, in the second embodiment, compared with the configuration in which the position of the first connection portion C1 in the circumferential direction is the same as that of the second connection portion C2 in the circumferential direction, the time required for the liquid to reach the inside of the housing 10 is longer. Therefore, it is possible to reduce the penetration of liquid into the sealing structure 100 for a long time.

[0084] [Third embodiment]

[0085] Fig. 9 2 is a plan view showing a gasket 20 according to a third embodiment. Fig. 9As shown in , as in the first embodiment, the gasket 20 according to the third embodiment includes a first annular portion P1, a second annular portion P2, a third annular portion P3, a plurality of first connecting portions C1, and a plurality of second connecting portions C2. The planar shape of each annular portion P according to the third embodiment is in the shape of a rectangular (e.g., square) ring, while the planar shape of each annular portion P according to the first embodiment is in the shape of a circular ring. The second annular portion P2 is positioned radially inwardly of the first annular portion P1 with a first gap D1 therebetween, and the third annular portion P3 is positioned inside the second annular portion P2 with a second gap D2 therebetween. The width W1 of the first gap D1 is the same as the width W2 of the second gap D2.

[0086] In addition, each first connection portion C1 connects the first annular portion P1 and the second annular portion P2 in a portion of the first gap D1, and each second connection portion C2 connects the second annular portion P2 and the third annular portion P3 in a portion of the second gap D2. As in the first embodiment, the position of the first connection portion C1 in the circumferential direction is the same as the position of the second connection portion C2 in the circumferential direction. In other words, the position of the first connection portion C1 in the direction along the shape of the gasket 20 is the same as the position of the second connection portion C2 in the direction along the shape of the gasket 20. As described above, also in the third embodiment, the first gap D1 and the second gap D2 delay the penetration of liquid. Therefore, as in the first embodiment, it is possible to reduce the penetration of liquid into the sealing structure 100.

[0087] Furthermore, as in the first embodiment, in the third embodiment, each annular portion P is constituted by a stack of the base portion 21, the first elastic layer 22, and the second elastic layer 23, and each connecting portion C is constituted by the base portion 21. In other words, each connecting portion C includes neither the first elastic layer 22 nor the second elastic layer 23. Therefore, each connecting portion C is thinner than each annular portion P.

[0088] like Fig. 9 As shown in , a plurality of through holes H are formed in the first annular portion P1 according to the third embodiment. Each through hole H is a circular opening into which a fastener 12 for fixing the first shell 10a and the second shell 10b to each other is inserted. Specifically, eight through holes H are formed at regular intervals. Fig. 9 , reference numeral H1 is assigned to two through holes H selected from among the plurality of through holes H. In FIG.

[0089] The first connection portion C1 and the second connection portion C2 are formed near the through hole H. Specifically, the first connection portion C1 is formed to include a point closest to one through hole H1 in the first gap D1. In other words, the first connection portion C1 is formed between the through hole H1 and the central axis O in the first gap D1. Similarly, the second connection portion C2 is formed to include a point closest to one through hole H1 in the second gap D2. In other words, the second connection portion C2 is formed between the through hole H1 and the central axis O in the second gap D2.

[0090] In the vicinity of the fastener 12, the first housing 10a and the second housing 10b are firmly fastened by the fastener 12 to sufficiently compress the gasket 20. Therefore, compared with other parts of the gasket 20, liquid hardly penetrates into the vicinity of the through hole H in the gasket 20, and as a result, the tendency of corrosion of the housing 10 is reduced. In the third embodiment, since the first connection portion C1 and the second connection portion C2 are formed in the vicinity of the through hole H, the possibility of liquid penetrating into the inside of the housing 10 via the first connection portion C1 or the second connection portion C2 is reduced. Therefore, the following effect is particularly significant: the penetration of liquid into the sealing structure 100 can be reduced for a long time.

[0091] [Fourth embodiment]

[0092] Fig.10 2 is a plan view showing a gasket 20 according to a fourth embodiment. Fig.10 As shown in , as in the first embodiment, the gasket 20 according to the fourth embodiment includes a first annular portion P1, a second annular portion P2, a third annular portion P3, a plurality of first connecting portions C1 and a plurality of second connecting portions C2. As in the third embodiment, the planar shape of each annular portion P is in the shape of a rectangular (e.g., square) ring. The second annular portion P2 is positioned at the radial inner side of the first annular portion P1 in a manner separated by a first gap D1, and the third annular portion P3 is positioned at the radial inner side of the second annular portion P2 in a manner separated by a second gap D2. Each first connecting portion C1 connects the first annular portion P1 and the second annular portion P2 in a portion of the first gap D1, and each second connecting portion C2 connects the second annular portion P2 and the third annular portion P3 in a portion of the second gap D2. As described above, as in the first embodiment, also in the fourth embodiment, since the first gap D1 and the second gap D2 delay the penetration of the liquid, it is possible to reduce the penetration of the liquid into the sealing structure 100.

[0093] Furthermore, as in the second embodiment, in the fourth embodiment, the position of the first connection portion C1 in the circumferential direction (or the position in the direction along the shape of the gasket 20) is different from the position of the second connection portion C2 in the circumferential direction. Furthermore, as in the second embodiment, each annular portion P and each connection portion C are constituted by a stack of the base portion 21, the first elastic layer 22, and the second elastic layer 23. Therefore, each connection portion C is as thick as each annular portion P.

[0094] As in the third embodiment, one of the plurality of fasteners 12 is inserted into each of the plurality of through holes formed in the first annular portion P1 according to the fourth embodiment. Fig.10 , reference numeral H1 is assigned to two through holes H selected from a plurality of through holes H, and reference numeral H2 is assigned to the other two through holes H. In FIG.

[0095] As in the third embodiment, each of the first connection portion C1 and the second connection portion C2 is formed in the vicinity of the through hole H. Specifically, the first connection portion C1 is formed to include a point closest to one through hole H1 in the first gap D1. In other words, the first connection portion C1 is formed between the through hole H1 and the central axis O in the first gap D1. Similarly, the second connection portion C2 is formed to include a point closest to one through hole H2 in the second gap D2. In other words, the second connection portion C2 is formed between the through hole H2 and the central axis O in the second gap D2.

[0096] As in the fourth embodiment, in the configuration in which each connection portion C is as thick as each annular portion P, the first recess R1 and the second recess R2 as described in the first embodiment are not formed. Therefore, the liquid that penetrates from the outside of the sealing structure 100 can penetrate forward toward the inside in the radial direction along the first connection portion C1 or the second connection portion C2. In the fourth embodiment, since the penetration of the liquid is reduced by installing each of the first connection portion C1 and the second connection portion C2 near the through hole H, the following effect is particularly significant: the penetration of the liquid into the sealing structure 100 can be reduced for a long time.

[0097] [Fifth embodiment]

[0098] Fig.11 is a plan view showing a gasket 20 according to a fifth embodiment. Fig.12 It is along Fig.11 A cross-sectional view of line ee in FIG. Fig.11 and Fig.12 As shown in FIG. 1 , a protrusion 25 is formed in each annular portion P (P1, P2, P3). Fig.12It can be understood that the protrusion 25 is a full flange protruding from the surface of each annular portion P. The surface of each annular portion P faces the end surface E1 of the first housing 10a (or the end surface E2 of the second housing 10b). In a plan view, the protrusion 25 extends in the circumferential direction. Specifically, in a plan view, the protrusion 25 is formed in the shape of a ring over the entire circumference of the gasket 20. In other words, the protrusion 25 extends along the annular portion P.

[0099] Also in the fifth embodiment, the same effects as those in the first embodiment are achieved. In addition, in the fifth embodiment, since the protrusion 25 of each annular portion P makes surface contact with the end surface E1 of the first housing 10a, liquid penetration from between the end surface E1 and the gasket 20 can be reduced.

[0100] exist Fig.11 , a configuration in which the protrusion 25 is added to the first embodiment is shown, in which the first elastic layer 22 and the second elastic layer 23 are not formed in each connection portion C. However, the protrusion 25 according to the fifth embodiment may be added to the second embodiment in which the first elastic layer 22 and the second elastic layer 23 are formed in each connection portion C. Furthermore, the protrusion 25 according to the fifth embodiment may be added to a configuration in which the planar shape of each annular portion P is in the shape of a rectangular ring as in the third embodiment or the fourth embodiment.

[0101] [Sixth embodiment]

[0102] Fig.13 is a plan view showing a gasket 20 according to a sixth embodiment. As in the second embodiment, the gasket 20 according to the sixth embodiment includes a first annular portion P1, a second annular portion P2, a third annular portion P3, a plurality of first connecting portions C1, and a plurality of second connecting portions C2. As in the second embodiment, the position of the first connecting portion C1 in the circumferential direction is different from the position of the second connecting portion C2 in the circumferential direction. In addition, as in the second embodiment, each annular portion P and each connecting portion C are composed of a stack of a base portion 21, a first elastic layer 22, and a second elastic layer 23.

[0103] like Fig.13 As shown in , in the sixth embodiment, the width W1 of the first gap D1 is different from the width W2 of the second gap D2 (W1≠W2). Specifically, the width W2 of the second gap D2 located on the inner peripheral side is greater than the width W1 of the first gap D1 located on the outer peripheral side (W2>W1).

[0104] Also in the sixth embodiment, the same effect as that of the first embodiment is achieved. In addition, in the sixth embodiment, since the width W2 of the second gap D2 is greater than the width W1 of the first gap D1, a volume sufficient to accumulate liquid is ensured in the second gap D2. Therefore, the time period from the time when the liquid starts to penetrate the second gap D2 to the time when the liquid fills the gap D2 is fully ensured. In other words, the above effect is particularly significant: the penetration of liquid into the sealing structure 100 can be reduced for a long time.

[0105] like Fig.14 As shown in FIG. 1 , in the gasket 20 where the position of the first connection portion C1 in the circumferential direction is the same as the position of the second connection portion C2 in the circumferential direction, a configuration in which the width W2 of the second gap D2 is greater than the width W1 of the first gap D1 may be adopted, such as Fig.13 In addition, Fig.15 As shown in , in the gasket 20 according to the third embodiment or the fourth embodiment in which the planar shape of each annular portion P is in the shape of a rectangular ring, a configuration in which the width W2 of the second gap D2 is larger than the width W1 of the first gap D1 may be adopted.

[0106] In the above description, a configuration is described in which the width W2 of the second gap D2 is larger than the width W1 of the first gap D1. However, a configuration in which the width W1 of the first gap D1 is larger than the width W2 of the second gap D2 (W1>W2) may also be assumed.

[0107] [Seventh embodiment]

[0108] Fig.16 2 is a plan view showing a gasket 20 according to a seventh embodiment. The gasket 20 according to the seventh embodiment includes a first annular portion P1, a second annular portion P2, a plurality of first connecting portions C1, and a plurality of third connecting portions C3. Each annular portion P (P1, P2) and each connecting portion C (C1, C3) is composed of a stack of a base portion 21, a first elastic layer 22, and a second elastic layer 23. For convenience, each cross-sectional view ( Figures 17 to 25 ), the illustration of the stacking structure of the gasket 20 is omitted.

[0109] Each of the first annular portion P1 and the second annular portion P2 is an annular portion formed in a circular shape in a plan view. The second annular portion P2 is positioned at the radial inner side of the first annular portion P1, and the first gap D1 is located between the first annular portion P1 and the second annular portion P2. The width of the first annular portion P1 is the same as the width of the second annular portion P2. Therefore, the first gap D1 is positioned at the center in the width direction of the gasket 20.

[0110] Each of the first connection portions C1 connects the first annular portion P1 and the second annular portion P2 in a portion of the first gap D1. Similarly, each of the third connection portions C3 connects the first annular portion P1 and the second annular portion P2 in a portion of the first gap D1. A set of one first connection portion C1 and one third connection portion C3 adjacent to each other in a spaced manner in the circumferential direction forms the attachment portion 30. As shown in FIG. Fig.16 It can be understood that the plurality of attachment portions 30 are formed at regular intervals along the circumferential direction.

[0111] The space between the first connection portion C1 and the third connection portion C3 constituting each attachment portion 30 is a through hole H. As described above, the through hole H is a circular opening into which the fastener 12 is inserted. As can be understood from the above description, a plurality of through holes H are formed at regular intervals along the circumferential direction. Each first gap D1 extends in the circumferential direction between two attachment portions 30 adjacent in the circumferential direction.

[0112] Fig.17 1 is a cross-sectional view showing the vicinity of the attachment portion 30 in a state where the fastener 12 is inserted into the through hole H. As shown in FIG. Fig.17 Corresponding to along Fig.16 Cross-sectional view along line ff. Fig.16 and Fig.17 The circular dotted line shown in illustrative figures shows the periphery Sb of the bearing surface Sa in the fastener 12 . Fig.17 A bolt 12a and a gasket 12b are shown as the fastener 12. The bolt 12a is inserted into the through hole H. The gasket 12b is an annular plate-shaped portion located between the head 12c of the bolt 12a and the surface of the first housing 10a. In the above-mentioned configuration, the periphery Sb of the gasket 12b corresponds to the periphery Sb of the support surface Sa in the fastener 12. In the configuration in which the gasket 12b is omitted, the periphery of the bottom surface (i.e., the support surface) in the head 12c of the bolt 12a corresponds to the periphery Sb of the support surface Sa.

[0113] As from Fig.16 and Fig.17 It can be understood that, in a plan view viewed from the direction of the center axis O, the attachment portion 30 is positioned at the radial inside of the periphery Sb on the bearing surface Sa of the fastener 12. Specifically, in a plan view, the first connection portion C1 and the third connection portion C3 are positioned at the radial inside of the periphery Sb of the fastener 12 to be inserted into the through hole H between the first connection portion C1 and the third connection portion C3. In other words, in a plan view, the first connection portion C1 and the third connection portion C3 overlap with the bearing surface Sa of the fastener 12.

[0114] As described in the third embodiment, since the first shell 10a and the second shell 10b are firmly fastened in the vicinity of the fastener 12 by the fastener 12, the gasket 20 is sufficiently compressed. Therefore, compared with other parts of the gasket 20, liquid hardly penetrates into the vicinity of the through hole H in the gasket 20, and as a result, the tendency of the housing 10 to corrode is reduced. In the seventh embodiment, since the fastener 12 is inserted into the through hole H formed by the first connection portion C1 and the third connection portion C3, the possibility of liquid penetrating into the housing 10 from the vicinity of the attachment portion 30 is reduced. Therefore, the following effect is particularly significant: the penetration of liquid into the sealing structure 100 can be reduced for a long time. In particular, in the seventh embodiment, since the first connection portion C1 and the third connection portion C3 are positioned at the radial inner side of the peripheral edge Sb in the support surface Sa of the fastener 12, the following effect is particularly significant: the possibility of liquid penetrating into the housing 10 from the vicinity of the attachment portion 30 is reduced.

[0115] Fig.18 It is along Fig.16 The cross-sectional view of line gg in FIG. Fig.18 As shown in FIG. 1 , the gasket 20 according to the seventh embodiment includes a first protrusion 25 a and a second protrusion 25 b. Fig.16 In the figure, each ridge line of the first protrusion 25a and the second protrusion 25b is shown by a dotted line. Fig.18 As shown in FIG. 1 , one direction along the central axis O is indicated as “X1 direction” and the other direction is indicated as “X2 direction”. When viewed from the gasket 20 , the first housing 10 a is positioned in the X1 direction, and when viewed from the gasket 20 , the second housing 10 b is positioned in the X2 direction.

[0116] The first protrusion 25a is a full flange formed in the first annular portion P1 and extending in the shape of a ring along the shape of the first annular portion P1. The first protrusion 25a according to the seventh embodiment protrudes in the X1 direction. Specifically, the first protrusion 25a protrudes from the surface of the first annular portion P1 toward the first shell 10a in the X1 direction, and the surface of the first annular portion P1 faces the end surface E1 of the first shell 10a. On the other hand, an annular groove 26a (recess) corresponding to the first protrusion 25a is formed on the surface of the first annular portion P1 facing the second shell 10b.

[0117] Similarly, the second protrusion 25b is a full flange formed in the second annular portion P2 and extending in the shape of a ring along the shape of the second annular portion P2. The second protrusion 25b according to the eighth embodiment protrudes in the X1 direction. Specifically, the second protrusion 25b protrudes in the X1 direction from the surface of the second annular portion P2 toward the first shell 10a, and the surface of the second annular portion P2 faces the end face E1 of the first shell 10a. On the other hand, an annular groove 26b (recess) corresponding to the second protrusion 25b is formed on the surface of the second annular portion P2 facing the second shell 10b.

[0118] As can be understood from the above description, the first protrusion 25a is formed between the first gap D1 and the outer peripheral edge of the gasket 20, and the second protrusion 25b is formed between the first gap D1 and the inner peripheral edge of the gasket 20. The first protrusion 25a and the second protrusion 25b according to the seventh embodiment protrude in the same direction (X1 direction), respectively.

[0119] Also in the seventh embodiment, the same effects as those of the first embodiment are achieved. In addition, in the seventh embodiment, since the first protrusion 25a and the second protrusion 25b make surface contact with the end surface E1 of the first housing 10a, liquid penetration between the end surface E1 and the gasket 20 can be effectively reduced.

[0120] Fig.19 2 is a cross-sectional view showing the gasket 20 in a state where the gasket 20 is placed between the first housing 10a and the second housing 10b (ie, in a use state). Fig.19 As shown in FIG. 1 , in the use state, a plurality of annular gaps G are formed between the gasket 20 and the end surface E1 of the first housing 10a or the end surface E2 of the second housing 10b. In the above configuration, liquid permeated from the outside of the sealing structure 100 accumulates in the gaps G in addition to accumulating in the first gaps D1. Therefore, according to the seventh embodiment, as compared with a configuration in which the gasket 20 is a uniform flat member, the penetration of liquid into the sealing structure 100 can be reduced over a long period of time.

[0121] [Eighth Embodiment]

[0122] and Fig.16 As in the seventh embodiment shown in FIG. 1 , the gasket 20 according to the eighth embodiment includes a first annular member P1, a second annular member P2, a plurality of first connecting portions C1, and a plurality of third connecting portions C3. Each annular member P (P1, P2) and each connecting portion C (C1, C3) are composed of a stack of a base portion 21, a first elastic layer 22, and a second elastic layer 23. The configuration in which the attachment portion 30 is positioned radially inward of the peripheral edge Sb in the bearing surface Sa of the fastener 12 is the same as that of the seventh embodiment.

[0123] Fig. 20is a sectional view showing a gasket 20 according to an eighth embodiment. Fig. 20 The seventh embodiment is shown in FIG. Fig.18 The corresponding cross section. Fig. 20 As shown in , in the eighth embodiment, as in the seventh embodiment, an annular first protrusion 25 a is formed in the first annular member P1 , and an annular second protrusion 25 b is formed in the second annular member P2 .

[0124] As in the seventh embodiment, the first protrusion 25a is an annular full flange protruding in the X1 direction. Specifically, the first protrusion 25a protrudes from the surface of the first annular member P1 toward the first housing 10a in the X1 direction, and the surface of the first annular member P1 faces the end surface E1 of the first housing 10a. An annular groove 26a corresponding to the first protrusion 25a is formed on the surface of the first annular member P1 facing the second housing 10b.

[0125] On the other hand, the second protrusion 25b is an annular full flange protruding in the X2 direction opposite to the X1 direction. Specifically, the second protrusion 25b protrudes from the surface of the second annular member P2 toward the second housing 10b, and the surface of the second annular member P2 faces the end surface E2 of the second housing 10b. An annular groove 26b corresponding to the second protrusion 25b is formed on the surface of the second annular member P2 facing the first housing 10a. As described above, in the eighth embodiment, the protruding direction of the first protrusion 25a is opposite to the protruding direction of the second protrusion 25b.

[0126] Also in the eighth embodiment, the same effects as those of the seventh embodiment are achieved. Fig.21 2 is a cross-sectional view showing the gasket 20 in use. Fig.21 As shown in FIG. 1 , an annular gap G is formed between the gasket 20 and the end surface E1 of the first housing 10a or the end surface E2 of the second housing 10b. In the above configuration, liquid permeated from the outside of the sealing structure 100 accumulates in the gap G in addition to the first gap D1. Therefore, according to the eighth embodiment, as with the seventh embodiment, the penetration of liquid into the sealing structure 100 can be reduced over a long period of time compared to a configuration in which the gasket 20 is a uniform flat member.

[0127] In the configuration in which the first protrusion 25a and the second protrusion 25b protrude in the same direction as the seventh embodiment, warping may occur between the inner peripheral edge of the gasket 20 and the outer peripheral edge of the gasket 20. According to the seventh embodiment, since the first protrusion 25a and the second protrusion 25b protrude in directions opposite to each other, the following effect can be obtained compared with the seventh embodiment: the warping of the gasket 20 can be reduced.

[0128] [Ninth Embodiment]

[0129] and Fig.16 As in the seventh embodiment shown in FIG. 1 , the gasket 20 according to the ninth embodiment includes a first annular portion P1, a second annular portion P2, a plurality of first connecting portions C1, and a plurality of third connecting portions C3. Each annular portion P (P1, P2) and each connecting portion C (C1, C3) is composed of a stack of a base portion 21, a first elastic layer 22, and a second elastic layer 23. The configuration in which the attachment portion 30 is positioned radially inward of the peripheral edge Sb in the bearing surface Sa of the fastener 12 is the same as that in the seventh embodiment.

[0130] Fig. 22 is a sectional view showing a gasket 20 according to a ninth embodiment. Fig. 22 The seventh embodiment is shown in FIG. Fig.18 The corresponding cross section. Fig. 22 As shown in , in the ninth embodiment, as in the seventh embodiment, the annular first protrusion 25a is formed in the first annular portion P1, and the annular second protrusion 25b is formed in the second annular portion P2.

[0131] The first protrusion 25a is a curved flange that protrudes in the X1 direction toward the first housing 10a. Fig. 22 As shown in , the first annular portion P1 includes a flat portion P11 and an inclined portion P12. The flat portion P11 is an annular portion, and the inclined portion P12 is an annular portion continuous with the outer peripheral edge of the flat portion P11. The flat portion P11 is a sheet-like portion parallel to a plane perpendicular to the central axis O (hereinafter referred to as a "reference plane"). The inclined portion P12 is a sheet-like portion inclined relative to the reference plane. Specifically, the inclined portion P12 is inclined toward the reference plane so that the inner peripheral edge of the inclined portion is away from the outer peripheral edge of the inclined portion in the X1 direction. The boundary between the flat portion P11 and the inclined portion P12 acts as a first protrusion 25a.

[0132] The second protrusion 25b is a half flange that protrudes toward the first housing 10a in the X1 direction. Fig. 22 As shown in , the second annular portion P2 includes a flat portion P21, an inclined portion P22, and a flat portion P23. The flat portion P21 is an annular portion. The flat portion P23 is an annular portion surrounding the flat portion P21. The inclined portion P22 is an annular portion connecting the flat portion P21 and the flat portion P23.

[0133] The flat portion P21 and the flat portion P23 are sheet-like portions parallel to the reference plane. The inclined portion P22 is a sheet-like portion inclined relative to the reference plane. Specifically, the inclined portion P22 is inclined toward the reference plane so that the inner peripheral edge of the inclined portion is away from the outer peripheral edge of the inclined portion in the X1 direction. In other words, the flat portion P21 is away from the flat portion P23 in the X1 direction. The boundary between the flat portion P21 and the inclined portion P22 acts as a second protrusion 25b.

[0134] Also in the ninth embodiment, the same effect as that of the first embodiment is achieved. In addition, as in the seventh embodiment, in the ninth embodiment, since the first protrusion 25a and the second protrusion 25b are in surface contact with the end surface E1 of the first shell 10a, liquid penetration between the end surface E1 and the gasket 20 can be effectively reduced.

[0135] Fig.23 2 is a cross-sectional view showing the gasket 20 in use. Fig.23 As shown in FIG. 1 , a plurality of annular gaps G are formed between the gasket 20 and the end surface E1 of the first housing 10a or the end surface E2 of the second housing 10b. In the above configuration, liquid permeated from the outside of the sealing structure 100 accumulates in the gaps G in addition to the first gaps D1. Therefore, according to the ninth embodiment, as with the seventh embodiment, the penetration of liquid into the sealing structure 100 can be reduced over a long period of time, compared with a configuration in which the gasket is a uniform flat member.

[0136] [Tenth embodiment]

[0137] Fig.24 is a sectional view showing the configuration of a gasket 40 according to a tenth embodiment. Fig.24 The seventh embodiment is shown in FIG. Fig.18 The gasket 40 according to the tenth embodiment includes a gasket 20a and a gasket 20b. Each structure of the gasket 20a and the gasket 20b is the same as that shown in the ninth embodiment. The gasket 20a and the gasket 20b are stacked so that the gasket 20a is away from the gasket 20b in the X1 direction.

[0138] Fig.25 4 is a cross-sectional view showing the gasket 40 in a used state. The gasket 20a is positioned between the gasket 20b and the first housing 10a, and the gasket 20b is positioned between the gasket 20a and the second housing 10b. Fig.25As shown in , the gasket 20a and the gasket 20b are stacked so that the first protrusion 25a and the second protrusion 25b in the gasket 20b are in contact with the end surface E2 of the second shell 10b, and the first protrusion 25a and the second protrusion 25b in the gasket 20a are in contact with the end surface E1 of the first shell 10a. In the above-mentioned configuration, a plurality of annular gaps G are formed between the gasket 20a and the end surface E1 of the first shell 10a, and a plurality of annular gaps G are formed between the gasket 20b and the end surface E2 of the second shell 10b. Therefore, as in the seventh embodiment, it is possible to reduce the penetration of liquid into the sealing structure 100 for a long time.

[0139] [Eleventh Embodiment]

[0140] Fig.26 1 is a plan view showing a gasket 20 according to an eleventh embodiment. The gasket 20 according to the eleventh embodiment has the following configuration: Fig.16 In the gasket 20 of the seventh embodiment shown in FIG. 1 , a third gap D3 is formed instead of the first protrusion 25a. The third gap D3 is an arc-shaped space extending in the circumferential direction. The first gap D1 and the third gap D3 are formed between two through holes H adjacent to each other in the circumferential direction.

[0141] As in the seventh embodiment, the second protrusion 25b is formed in the second annular portion P2. The second protrusion 25b is formed in the shape of a ring along the inner peripheral edge of the gasket 20. The first gap D1 is formed between the second protrusion 25b and the outer peripheral edge of the gasket 20, and the third gap D3 is formed between the first gap D1 and the outer peripheral edge of the gasket. In other words, the second protrusion 25b is positioned in the area on the inner peripheral side of the first gap D1, and the third gap D3 is formed in the area on the outer peripheral side of the first gap D1. In other words, the first gap D1 is positioned between the second protrusion 25b and the third gap D3.

[0142] According to the above structure, the penetration of liquid through the first gap D1 and the third gap D3 can be reduced. In addition, the penetration of liquid can be reduced by the structure in which the second protrusion 25b is in surface contact with the end surface E1 of the first shell 10a. Therefore, the following effect is particularly significant: the penetration of liquid into the sealing structure 100 can be reduced for a long time.

[0143] [Twelfth embodiment]

[0144] Fig. 27 1 is a partial perspective view showing a gasket 20 in the twelfth embodiment. As in the first embodiment, the gasket 20 in the twelfth embodiment includes a first annular portion P1, a second annular portion P2, and a third annular portion P3.

[0145] like Fig. 27As shown in FIG. 1 , a hydrophilic film 50 covering the inner peripheral surface of each annular portion P is formed on the inner peripheral surface. The hydrophilic film 50 is a thin film having hydrophilicity (wettability) to the liquid penetrating into the sealing structure 100. The hydrophilicity of the hydrophilic film 50 is higher than the hydrophilicity of the inner peripheral surface of the annular portion P. In order to form the hydrophilic film 50, a freely selected known material having hydrophilicity is used.

[0146] Also in the twelfth embodiment, the same effects as those of the first embodiment are achieved. In addition, in the twelfth embodiment, since the hydrophilic film 50 is formed on the inner peripheral surface of the annular portion P, the liquid that has reached the first gap D1 is promoted to penetrate along the inner peripheral surface of the first annular portion P1 in the direction of the arrow A2. In addition, the liquid that has reached the second gap D2 is promoted to penetrate along the inner peripheral surface of the second annular portion P2 in the direction of the arrow A4. In other words, the penetration of the liquid into the housing 10 can be delayed. Therefore, according to the twelfth embodiment, the penetration of the liquid into the sealing structure 100 can be reduced for a long time.

[0147] exist Fig. 27 , a configuration in which the hydrophilic film 50 is formed on each inner circumferential surface of all the annular portions P is shown. However, the hydrophilic film 50 may be formed only on the inner circumferential surface of a portion of the annular portion P. For example, in a configuration in which the first annular portion P1, the second annular portion P2, and the third annular portion P3 are provided as in the first embodiment, a configuration in which the hydrophilic film 50 is formed on each inner circumferential surface of the first annular portion P1 and the second annular portion P2, while the hydrophilic film 50 is not formed on the inner circumferential surface of the third annular portion P3. Furthermore, in a configuration in which the first annular portion P1 and the second annular portion P2 are provided as in the seventh embodiment, a configuration in which the hydrophilic film 50 is formed on the inner circumferential surface of the first annular portion P1, while the hydrophilic film 50 is not formed on the inner circumferential surface of the second annular portion P2 may be assumed.

[0148] Fig. 27 A configuration is shown in which the hydrophilic film 50 is formed on the inner peripheral surface of each annular portion P. However, a configuration may be assumed in which the hydrophilic film 50 is formed on the outer peripheral surface of each annular portion P, or the hydrophilic film 50 is formed on both the inner and outer peripheral surfaces of each annular portion P. In other words, the hydrophilic film 50 is formed on the inner wall surface of the first gap D1 or the second gap D2.

[0149] [Variation]

[0150] Various modifications can be made to each embodiment described above. The following describes specific modifications that can be applied to each embodiment described above. As long as there is no conflict, two or more aspects freely selected from the following description can be appropriately combined.

[0151] (1) In each of the above-mentioned embodiments, a gasket 20 including three annular portions P (P1, P2, P3) is described. However, the number of annular portions P constituting the gasket 20 is not limited to three. For example, a configuration in which the gasket 20 includes two annular portions P (P1, P2) as described in the sixth to eleventh embodiments, or a configuration in which the gasket 20 includes four or more annular portions P, may be assumed. Therefore, the number of gaps D (D1, D2) is not limited to the description (two positions) in each of the above-mentioned embodiments. For example, a configuration in which only one gap D is formed in the gasket 20 as described in the sixth to eleventh embodiments, or a configuration in which three or more gaps D are formed in the gasket 20, may also be assumed.

[0152] (2) In the above-mentioned various embodiments, the gasket 20 including two first connection parts C1 and two second connection parts C2 is described. However, the number of connection parts C constituting the gasket 20 is not limited to the above description. For example, it is also possible to assume a configuration in which the gasket 20 includes only one first connection part C1, or a configuration in which the gasket 20 includes three or more first connection parts C1. Similarly, it is also possible to assume a configuration in which the gasket 20 includes only one second connection part C2, or a configuration in which the gasket 20 includes three or more second connection parts C2.

[0153] The number of the first connection parts C1 may be different from the number of the second connection parts C2.

[0154] (3) In the above-mentioned various embodiments, the annular portion P in the shape of a ring having a circular or rectangular planar shape is described. However, the shape of the annular portion P is not limited to the above description. For example, an annular portion P having a planar shape such as an ellipse or a polygon (polygon such as a triangle or a hexagon) may be assumed. In addition, each planar shape of the plurality of annular portions P may be different from each other. For example, the following configuration may also be adopted: the planar shape of the first annular portion P1 is a rectangle, and the planar shape of the second annular portion P2 is a circle.

[0155] (4) The dimensional relationship between the width of each annular portion P and the width of each gap D can be freely selected. For example, a configuration is assumed in which the width of the annular portion P is the same as the width of the gap D. In addition, a configuration in which the width of the annular portion P is larger than the width of the gap D, or the width of the annular portion P is smaller than the width of the gap D can also be adopted.

[0156] (5) In the above-described respective embodiments, the gasket 20 composed of the stack of the base portion 21, the first elastic layer 22, and the second elastic layer 23 is described. However, the cross-sectional structure of the gasket 20 is not limited thereto. For example, the gasket 20 having the shape according to each of the above-described embodiments may be formed of a single layer, or the gasket 20 may be formed of a stack of four or more layers. Furthermore, the first elastic layer 22 or the second elastic layer 23 may be omitted.

[0157] (6) The cross-sectional shape of the protrusion 25 of the fifth embodiment is not limited to Fig.12 For example, in Fig.12 , a protrusion 25 having an arc-shaped cross-sectional shape is shown. However, a protrusion 25 having a trapezoidal cross-sectional shape may be formed. A protrusion 25 having a step-shaped (half-flange) cross-sectional shape may be formed. In addition, as disclosed in, for example, Japanese Patent Application Publication No. 2013-11300, a protrusion 25 having a shape corresponding to an air hole that can be generated in the housing 10 may be formed.

[0158] (7) In the sixth to ninth embodiments, as in the first or third embodiment, the first connection portion C1 and the second connection portion C2 may be composed of a single layer including only the base portion 21 .

[0159] (8) The gasket 20 used in the sealing structure 100 of a vehicle such as an automobile has been shown. However, the field in which the gasket 20 is used is not limited to the above example. For example, the gasket according to the present invention can be used in industrial fields such as pipe connection.

[0160] Description of Reference Numerals

[0161] 100…sealing structure, 10a…first shell, 10b…second shell, 12…fastener, 12a…bolt, 12b…gasket, 20, 20a, 20b, 40…washer, 21…base portion, 22…first elastic layer 2, 23…second elastic layer, 25…protrusion, 25a…first protrusion, 25b…second protrusion, 30…attachment portion, 50…hydrophilic membrane, P1…first annular portion, P2…second annular portion, P3…third annular portion, C1…first connecting portion, C2…second connecting portion, C3…third connecting portion, D1…first gap, D2…second gap, D3…third gap, H…through hole, R1…first recess, R2…second recess, Sa…support surface, Sb…periphery of the support surface.

Claims

1. A gasket to be installed between a first shell and a second shell, the gasket comprising: A first annular portion having an annular shape; a second annular portion having an annular shape, the second annular portion being positioned radially inward of the first annular portion, with a first gap between the first annular portion and the second annular portion; as well as a first connecting portion connecting the first annular portion and the second annular portion in a portion of the first gap, The first connecting portion is thinner than both the first annular portion and the second annular portion, Each of the first annular portion and the second annular portion is a portion including a plate-shaped base portion made of metal and an elastic layer partially covering the base portion, and, The first connecting portion is a portion including the base portion but not including the elastic layer. A portion of the base corresponding to the first connection portion is exposed between the elastic layer of the first annular portion and the elastic layer of the second annular portion.

2. A gasket to be installed between a first shell and a second shell, the gasket comprising: A first annular portion having an annular shape; a second annular portion having an annular shape, the second annular portion being positioned radially inward of the first annular portion, with a first gap between the first annular portion and the second annular portion; a first connecting portion connecting the first annular portion and the second annular portion in a portion of the first gap; as well as a third connecting portion connecting the first annular portion and the second annular portion in a portion of the first gap, The space between the first connection part and the third connection part is a through hole, a fastener is inserted into the through hole, and the fastener connects the first shell and the second shell.

3. The gasket according to claim 2, wherein: The first connection portion and the third connection portion are positioned at an inner side of an outer peripheral edge of a bearing surface of the fastener in a plan view.

4. A gasket to be installed between a first shell and a second shell, the gasket comprising: A first annular portion having an annular shape; a second annular portion having an annular shape, the second annular portion being positioned radially inward of the first annular portion, with a first gap between the first annular portion and the second annular portion; as well as a first connecting portion connecting the first annular portion and the second annular portion in a portion of the first gap, A hydrophilic film is formed on the inner peripheral surface of at least one of the first annular portion or the second annular portion, and the hydrophilic film covers the inner peripheral surface.

5. The gasket according to any one of claims 1 to 4, wherein: A protrusion is formed, the protrusion protruding toward the first housing on a surface of at least one of the first annular portion or the second annular portion, the surface facing the first housing.

6. The gasket according to any one of claims 1 to 4, in, A first protrusion is formed on a facing surface of the first annular portion facing the first housing, the first protrusion protruding toward the first housing along the shape of the first annular portion, and A second protrusion is formed on a surface of the second annular portion facing the first housing, and the second protrusion protrudes toward the first housing along the shape of the second annular portion.

7. The gasket according to any one of claims 1 to 4, in, A first protrusion is formed on a facing surface of the first annular portion facing the first housing, the first protrusion protruding toward the first housing along the shape of the first annular portion, and A second protrusion is formed on a facing surface of the second annular portion facing the second housing, and the second protrusion protrudes toward the second housing along the shape of the second annular portion.

8. The gasket according to any one of claims 1 to 4, further comprising: a third annular portion in an annular shape, the third annular portion being disposed radially inward of the second annular portion, with a second gap being provided between the second annular portion and the third annular portion; as well as A second connecting portion connects the second annular portion and the third annular portion in a portion of the second gap.

9. The gasket according to claim 8, wherein: The first connection portion and the second connection portion are positioned on a straight line, wherein the straight line is orthogonal to a central axis of the gasket.

10. The gasket according to claim 8, wherein: The first connecting portion is positioned on a first straight line, The second connecting portion is positioned on a second straight line, Each of the first straight line and the second straight line is orthogonal to the central axis of the gasket, The first straight line and the second straight line intersect each other.

11. The gasket according to claim 8, wherein: A width of the first gap is different from a width of the second gap.

12. The gasket according to claim 11, wherein The width of the second gap is greater than the width of the first gap.

13. The gasket according to claim 1 or 4, in, A through hole is formed in the first annular portion, and a fastener is inserted into the through hole, wherein the fastener connects the first shell and the second shell, and Wherein, the first connection portion is formed near the through hole.

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