Sealing structure

Abstract

To prevent leakage of fluid by making a gasket stably exhibit sealability even when a taper portion is disposed on one of the two facing surfaces to be sealed by the gasket.SOLUTION: A sealing structure includes: first members (10, 90); a second member (20) having a hole part having a taper portion (25); a cylindrical part (30) or a screw part (92) to be inserted into the hole part; and a gasket arranged between the first member and the second member and in the radial outside of the cylindrical part or the screw part. The gasket has an elastic part (41) compressed between the first member and the second member. The elastic part has a first bead (45) and a second bead (46) formed at least on a surface at the second member side, and at least the first bead is compressed along the axial direction between the first member and the second member in the radial outside of the taper portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sealing structure having a gasket that seals between two opposing surfaces. [Background technology]

[0002] A seal washer described in Patent Document 1 is known as a seal that seals between two opposing surfaces to prevent fluid leakage between the two surfaces. This seal washer is placed between the head of a screw member and a member into which the screw member is fastened. A tapered portion is formed in the screw hole of the member into which the screw member is fastened to make it easier to fasten the screw member.

[0003] The seal washer described in Patent Document 1 can also be applied to a structure having a pipe inserted between two members. In this case, the seal washer is disposed between the two members and radially outward of the pipe. The hole in one of the two members through which the pipe is inserted may be tapered to facilitate insertion of the pipe. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-002894 Summary of the Invention [Problem to be solved by the invention]

[0005] When a gasket that is disposed around a hole with such a tapered portion and seals the gap between two opposing surfaces is compressed between the two surfaces, it may be guided by the inclined tapered portion and move radially inward, resulting in the gasket not being compressed properly. In particular, if the diameter of the tapered portion is larger than the design value due to manufacturing errors, the gasket is likely to move radially inward.

[0006] Therefore, the present invention provides a sealing structure that has a gasket that seals between two opposing surfaces, and that can suppress radial movement of the gasket, provide stable sealing performance, and prevent fluid leakage, even when a tapered portion is provided on one of the surfaces. [Means for solving the problem]

[0007] One aspect of the present invention provides a sealing structure. The sealing structure includes a first member having a first flat surface, a second flat surface opposing the first flat surface, and a hole having a circular cross section extending in a direction perpendicular to the second flat surface, the hole having a tapered portion formed along the axial direction of the hole with a diameter increasing toward the second flat surface. A cylindrical or threaded portion inserted into the hole, and a gasket disposed between the first and second flat surfaces and radially outward of the cylindrical or threaded portion. The gasket includes an elastic portion made of an elastic material that is compressed along the axial direction between the first and second flat surfaces, and a rigid portion made of a rigid material that is fixed to the outer circumferential surface of the elastic portion and is brought into contact with the first and second flat surfaces. The elastic portion has a first surface that contacts the first flat surface, a second surface that contacts the second flat surface, an insertion hole through which the cylindrical portion or the threaded portion is inserted, at least a first annular bead formed on the second surface, and at least a second annular bead formed on the second surface concentrically with the first bead. Here, the second bead is located radially outward of the insertion hole, and the first bead is located radially outward of the second bead. When the elastic portion is not compressed along the axial direction, the thickness of the elastic portion at the first bead and the second bead is greater than the maximum thickness of the rigid portion. The first bead is compressed along the axial direction between the first flat surface and the second flat surface, radially outward of the tapered portion. [Effects of the Invention]

[0008] In one embodiment of the present invention, a first bead and a second bead are formed on at least the second surface of the elastic portion of the gasket. Of the first and second beads, at least the first bead located on the radially outer side is compressed between the first flat surface and the second flat surface on the radially outer side of the tapered portion. This allows the first bead to be compressed with a large crushing allowance (deformation amount) without being affected by manufacturing errors or inclination of the tapered portion, allowing the gasket to stably exhibit sealing performance. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a sealing structure according to an embodiment of the present invention before assembly. [Figure 2] 2 is a cross-sectional view of a portion of the gasket of the sealing structure of FIG. 1 before assembly. [Figure 3] 3 is a plan view of the gasket of FIG. 2 before assembly of the sealing structure. [Figure 4] FIG. 2 is a cross-sectional view of the sealing structure according to the embodiment after assembly. [Figure 5] 5 is a cross-sectional view of a portion of the gasket of the sealing structure of FIG. 4 after assembly. [Figure 6] FIG. 10 is a cross-sectional view of a gasket according to a comparative example in the middle of assembly. [Figure 7] FIG. 10 is a cross-sectional view of a sealing structure according to a modified example of the embodiment before assembly. [Figure 8] 8 is a cross-sectional view of the assembled sealing structure of FIG. 7. [Figure 9] FIG. 10 is a cross-sectional view of a portion of a gasket before assembly of a sealing structure according to another modified example of the embodiment. [Figure 10] FIG. 10 is a cross-sectional view of a portion of a gasket after assembly of a sealing structure according to yet another modified example of the embodiment. [Figure 11] FIG. 10 is a cross-sectional view of a sealing structure according to yet another modified example of the embodiment after assembly. [Figure 12] FIG. 10 is a cross-sectional view of a sealing structure according to yet another modified example of the embodiment after assembly. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The drawings are not necessarily drawn to scale, and some features may be exaggerated or omitted. The embodiments of the present invention will be described using the terms "upper," "lower," "right," "left," and "lateral," but this is for illustrative purposes only and does not limit the application of the embodiments of the present invention to the directions described.

[0011] As shown in FIG. 1, the sealing structure according to the embodiment of the present invention includes a first member 10, a second member 20, a cylindrical member (cylindrical portion) 30, a gasket 40, and a seal ring 60.

[0012] The first member 10 has a flat upper surface 11 and a flat lower surface (first flat surface) 12. The lower surface 12 is parallel to the upper surface 11, but does not have to be parallel. The first member 10 has a cylindrical member support through hole 13 into which a cylindrical member 30 having a circular cross section is inserted, and a plurality of fastener through holes 14 into which screw members (fasteners 65) described below are inserted. The material of the first member 10 is not particularly limited, but metals such as aluminum alloys and iron, or high-strength resin materials are preferred. By manufacturing the first member 10 from such a material, the screw members 65 can be reliably held when fastening the first member 10 to the cylindrical member 30 or the second member 20 described below.

[0013] The second member 20 has a flat upper surface (second flat surface) 21 and a flat lower surface 22. The upper surface 21 faces the lower surface 12 of the first member 10. The lower surface 22 is parallel to the upper surface 21, but does not have to be parallel. The second member 20 is formed with a cylindrical member accommodating through hole (hole portion) 23 that extends in a direction perpendicular to the second flat surface 21 and has a circular cross section, and a plurality of screw holes 24 into which screw members 65 (described later) are screwed. A cylindrical member 30 is inserted into the cylindrical member accommodating through hole 23. The cylindrical member accommodating through hole 23 has a tapered portion 25. The tapered portion 25 is formed in an annular shape at the upper end of the cylindrical member accommodating through hole 23 that opens at the upper surface 21, and has a diameter that decreases as it moves away from the upper surface 21. It can also be said that the tapered portion 25 has a diameter that increases as it moves closer to the upper surface 21. The tapered portion 25 can also be called a chamfered portion. Although there are no particular limitations on the material of the second member 20, metals such as aluminum alloys and iron, high-strength resin materials, etc. are preferred. By manufacturing the second member 20 from such materials, the screw member 65 can be securely held when fastened to the cylindrical member 30 or the first member 20.

[0014] The first member 10 and the second member 20 may be made of the same material or different materials, and the materials are selected appropriately based on the strength required of the product, the environment in which it will be used, cost, etc.

[0015] The cylindrical member 30 is inserted into the cylindrical member support through-hole 13 of the first member 10 and the cylindrical member accommodating through-hole 23 (hole portion) of the second member 20. Gas or liquid flows inside the cylindrical member 30. For example, the cylindrical member 30 may be a cooling pipe for a battery mounted on an electric vehicle (EV) or a hybrid electric vehicle (xHEV), or may be piping for an air conditioner. In these cases, a refrigerant, cooled water, heated water, or the like flows inside the cylindrical member 30. The cylindrical member 30 may also be piping for other purposes.

[0016] A circumferential groove 31 is formed on the outer peripheral surface of the lower end of the cylindrical member 30. A seal ring 60 made of an elastic material such as an elastomer containing rubber is fitted into the circumferential groove 31. In this embodiment, the seal ring 60 is an O-ring.

[0017] The gasket 40 is interposed between the lower surface 12 of the first member 10 and the upper surface 21 of the second member 20, and is disposed radially outside the cylindrical member 30 (surrounding the cylindrical member 30). This type of gasket is sometimes called a seal washer.

[0018] The gasket 40 has an elastic portion 41 and a rigid portion 50 disposed radially outward of the elastic portion 41 .

[0019] The elastic portion 41 is formed from an elastic material such as an elastomer containing rubber, and is disposed between the lower surface 12 of the first member 10 and the upper surface 21 of the second member 20. When pressed by the first member 10 and the second member 20, the elastic portion 41 is compressed along the axial direction of the cylindrical member accommodating through-hole 23.

[0020] As will be described later, the seal ring 60 and the elastic portion 41 of the gasket 40 prevent or reduce leakage of fluid inside the cylindrical member 30. When a refrigerant flows inside the cylindrical member 30 as described above, examples of preferred materials for the seal ring 60 and the elastic portion 41 of the gasket 40 are HNBR (Hydrogenated Nitrile Butadiene Rubber) or EPDM (Ethylene Propylene Diene Monomer), which have high chemical stability.

[0021] The rigid portion 50 is formed from a rigid material and fixed to the outer peripheral surface of the elastic portion 41. The material of the rigid portion 50 is not limited as long as it has lower elasticity than the material of the elastic portion 41 and can withstand the compressive force exerted by the first member 10 and the second member 20, temperature changes in the usage environment, and chemicals and moisture that may fly. For example, metallic materials such as stainless steel and cold-rolled steel plate (SPCC) specified in JIS (Japanese Industrial Standards) G3141 are preferred. For example, rigid materials other than metallic materials such as nylon 66 (PA66) and polyphenylene sulfide (PPS) resin are preferred. The rigid portion 50 is a plate having a uniform thickness. The rigid portion 50 has a plurality of insertion holes 51 formed therein, into which screw members 65, described later, are inserted. The insertion holes 51 are through-holes.

[0022] Fig. 2 shows an enlarged view of a portion of the gasket 40 in an uncompressed state before the sealing structure is assembled. Fig. 3 is a plan view of the gasket 40 in an uncompressed state before the sealing structure is assembled.

[0023] 1 and 2, in this embodiment, the gasket 40 has a shape that is plane-symmetrical with respect to a plane P that is perpendicular to the axis of the gasket 40. Therefore, the worker does not need to pay attention to the front and back of the gasket 40.

[0024] Referring to Figure 2, the elastic portion 41 of the gasket 40 has a thick outer portion 42 fixed to the rigid portion 50, a thin positioning annular portion 43 having a cylindrical annular portion inner circumferential surface 43c, and a connecting portion 44 that connects the outer portion 42 and the positioning annular portion 43 and has a cross section that tapers radially inward.

[0025] The outer portion 42 has a first surface 42A that is in contact (line contact or area contact) with the lower surface 12 of the first member 10, and a second surface 42B that is in contact (line contact or area contact) with the upper surface 21 of the second member 20. In this embodiment, the first surface 42A and the second surface 42B have the same shape, more precisely, shapes that are plane-symmetrical with respect to the plane P.

[0026] A first bead 45 and a second bead 46 are formed on each of the first surface 42A and the second surface 42B. "Beads are formed on the surface" means that the beads are located on the surface side. As shown in FIG. 3, the beads 45 and 46 are circular, endless protrusions that are arranged concentrically with each other. A recess 47 is formed between the beads 45 and 46.

[0027] As shown in Figure 2, when the elastic portion 41 is not compressed along the axial direction, the outlines of the beads 45, 46 in a cross section including the axis of the elastic portion 41 are elliptical arcs, and the outline of the recess 47 is also elliptical arcs.

[0028] 2, when the elastic portion 41 is not compressed in the axial direction, the thickness T1 of the elastic portion 41 in the first bead 45 is greater than the thickness T3 of the rigid portion 50. Although not absolutely necessary, in this state, the thickness T2 of the elastic portion 41 in the second bead 46 is preferably greater than the thickness T3 of the rigid portion 50. Also, although not absolutely necessary, in this state, the thickness T4 of the elastic portion 41 in the recess 47 is preferably greater than the thickness T3 of the rigid portion 50. Here, "thickness" refers to the length of the elastic portion 41 or the rigid portion 50 along the axial direction of the gasket 40.

[0029] The positioning annular portion 43 has an annular portion inner circumferential surface 43c, a first annular surface 43a, and a second annular surface 43b. The radially inner side of the annular portion inner circumferential surface 43c is an insertion hole portion 43d. That is, the annular portion inner circumferential surface 43c defines the insertion hole portion 43d. The cylindrical member 30 or the screw member 92 is inserted into the radially inner side of the annular portion inner circumferential surface 43c. The first annular surface 43a faces the lower surface 12 of the first member 10, and the second annular surface 43b faces the upper surface 21 of the second member 20. As shown in FIG. 2, when the elastic portion 41 is not compressed in the axial direction, the first annular surface 43a and the second annular surface 43b of the positioning annular portion 43 are perpendicular to the axial direction of the gasket 40 and parallel to each other.

[0030] 2 and 3 together. The second bead 46 is located radially outward of the insertion hole portion 43d. The first bead 45 is located radially outward of the second bead 46. The first bead 45 and the second bead 46 are annular. The second bead 46 is formed concentrically with the first bead 45.

[0031] 4, the first member 10, the second member 20, and the gasket 40 are fastened together by a threaded member, that is, a bolt (a rod-shaped fastener) 65. The threaded portion of the bolt 65 is inserted into the fastener through hole 14 of the first member 10 and the insertion hole 51 of the rigid portion 50 of the gasket 40, and is screwed into the threaded hole 24 of the second member 20.

[0032] Additionally, the cylindrical member 30 is inserted downward in the figure into the cylindrical member support through hole 13 of the first member 10 and the cylindrical member accommodating through hole 23 of the second member 20. Preferably, first, the gasket 40 is placed between the first member 10 and the second member 20. Thereafter, the cylindrical member 30 is inserted into the cylindrical member support through hole 13 and the cylindrical member accommodating through hole 23. Next, the first member 10, the second member 20, and the gasket 40 are fastened together with bolts 65, and the gasket 40 is compressed along the axial direction.

[0033] In the state shown in FIG. 4 , the elastic portion 41 of the gasket 40 is compressed along the axial direction of the cylindrical member accommodating through-hole 23 between the lower surface 12 of the first member 10 and the upper surface 21 of the second member 20, with the first surface 42A of the outer portion 42 of the elastic portion 41 in contact with the lower surface 12 of the first member 10 and the second surface 42B of the outer portion 42 in contact with the upper surface 21 of the second member 20. Therefore, even if fluid inside the cylindrical member 30 leaks into the gap between the outer surface of the cylindrical member 30 and the inner surface of the cylindrical member accommodating through-hole 23, the elastic portion 41 functions as a downstream seal, preventing or reducing leakage of the fluid through the gap between the first member 10 and the second member 20. The rigid portion 50 of the gasket 40 is in contact with the lower surface 12 of the first member 10 and the upper surface 21 of the second member 20 and functions as a spacer that secures a gap between the first member 10 and the second member 20.

[0034] Furthermore, when the cylindrical member 30 is inserted into the cylindrical member accommodating through hole 23 of the second member 20, the seal ring 60 fitted into the circumferential groove 31 at the lower end of the cylindrical member 30 is disposed inside the cylindrical member accommodating through hole 23 and is compressed between the inner circumferential surface of the cylindrical member accommodating through hole 23 and the outer circumferential surface of the cylindrical member 30. Therefore, the seal ring 60 functions as an upstream seal, closing the gap between the outer circumferential surface of the cylindrical member 30 and the inner circumferential surface of the cylindrical member accommodating through hole 23 of the second member 20, and preventing or reducing leakage of fluid inside the cylindrical member 30 through this gap.

[0035] Fig. 5 shows an enlarged view of a portion of the gasket 40 in a compressed state after the sealing structure is assembled as shown in Fig. 4. In this state, at least the first bead 45 (see Fig. 2) of the beads 45, 46 on the first surface 42A and the second surface 42B is compressed along the axial direction between the lower surface 12 of the first member 10 and the upper surface 21 of the second member 20, radially outward from the tapered portion 25 of the second member 20, and is flattened. Of the first bead 45 and the second bead 46, at least the radially outer first bead 45 is compressed between the lower surface 12 of the first member 10 and the upper surface 21 of the second member 20, radially outward from the tapered portion 25. Therefore, the first bead 45 is compressed with a large crushing allowance (amount of deformation) without being affected by manufacturing errors or tilt of the tapered portion 25, and the gasket 40 can stably exhibit sealing performance. The sum of the compression allowances of the first bead 45 on both surfaces 42A, 42B relative to the first member 10 and the second member 20 is T1-T3 (see FIG. 2).

[0036] Although not absolutely necessary, in this state, it is preferable that the second beads 46 on the first surface 42A and the second surface 42B of the outer portion 42 are also compressed along the axial direction between the lower surface 12 of the first member 10 and the upper surface 21 of the second member 20, and flattened, on the radially outer side of the tapered portion 25 of the second member 20. In addition to the radially outer first bead 45, the radially inner second bead 46 is also compressed between the lower surface 12 of the first member 10 and the upper surface 21 of the second member 20, on the radially outer side of the tapered portion 25. Therefore, the first bead 45 and the second bead 46 are compressed with a large crushing allowance (amount of deformation) without being affected by manufacturing errors or tilt of the tapered portion 25, and the gasket 40 can stably exhibit sealing performance. The sum of the compression allowances of the second bead 46 on both surfaces 42A, 42B relative to the first member 10 and the second member 20 is T2-T3 (see FIG. 2).

[0037] When the first bead 45 and the second bead 46 are compressed along the axial direction between the lower surface 12 of the first member 10 and the upper surface 21 of the second member 20 on the radially outer side of the tapered portion 25 of the second member 20, the thickness T1 of the elastic portion 41 of the first bead 45 before compression is preferably equal to or greater than the thickness T2 of the elastic portion 41 of the second bead 46 before compression. In this case, the crushing allowance (deformation amount) of the radially outer first bead 45 is greater than the crushing allowance (deformation amount) of the radially inner second bead 46, so that the first bead 45 can prevent or reduce fluid leakage even after the second bead 46 has deteriorated. Alternatively, even if a small amount of fluid leaks from the portion sealed by the second bead 46, the first bead 45 can provide a more airtight seal downstream, thereby more reliably preventing or reducing fluid leakage.

[0038] Furthermore, although not absolutely necessary, in this state, it is preferable that the recesses 47 between the first beads 45 and the second beads 46 on each of the first surface 42A and the second surface 42B of the outer portion 42 are also compressed along the axial direction between the lower surface 12 of the first member 10 and the upper surface 21 of the second member 20, on the radially outer side of the tapered portion 25 of the second member 20, and are flattened. In addition to the first beads 45 and the second beads 46, the recesses 47 are also compressed between the lower surface 12 of the first member 10 and the upper surface 21 of the second member 20, on the radially outer side of the tapered portion 25. Therefore, the outer portion 42 of the elastic portion 41 is compressed with a large crushing allowance (deformation amount) without being affected by manufacturing errors or tilt of the tapered portion 25, and the gasket 40 can stably exhibit sealing performance. Furthermore, even if the second bead 46 is damaged or a foreign object gets into the recess 47, the gasket 40 can stably provide sealing performance. The sum of the crushing allowances (deformation amounts) of the recess 47 on both surfaces 42A, 42B of the first member 10 and the second member 20 is T4-T3 (see FIG. 2).

[0039] The positioning annular portion 43, disposed inside the outer portion 42, extends toward the cylindrical member 30 and is disposed around the cylindrical member 30 inserted into the cylindrical member support through-hole 13 and the cylindrical member accommodating through-hole 23. The positioning annular portion 43 thereby positions the gasket 40 so that at least the first bead 45 (and more preferably the recess 47 and the second bead 46) are positioned radially outward of the tapered portion 25. With the gasket 40 disposed between the first member 10 and the second member 20 and before the bolts 65 are tightened, the gasket 40 can move laterally in the drawing (in a direction perpendicular to the axial direction of the gasket 40) between the first member 10 and the second member 20. However, the positioning annular portion 43 of the gasket 40 is disposed around the cylindrical member 30 (i.e., the entire cylindrical member 30 is surrounded by the positioning annular portion 43). In other words, the relative position of the positioning annular portion 43 and therefore the entire gasket 40 with respect to the cylindrical member 30 is determined. In this way, the cylindrical member 30 and the positioning annular portion 43 restrict lateral movement of the gasket 40, so that at least the first bead 45 (and more preferably the recessed portion 47 and the second bead 46) are reliably positioned outside the tapered portion 25. Therefore, the gasket 40 can stably exhibit sealing properties.

[0040] With the elastic portion 41 of the gasket 40 compressed in the axial direction, the positioning annular portion 43 extends radially inward as described below, so that the positioning annular portion 43 comes into contact with the outer circumferential surface of the cylindrical member 30 over the entire circumference. Therefore, lateral movement of the gasket 40 between the first member 10 and the second member 20 is further restricted, and the gasket 40 is positioned so that at least the first bead 45 (and more preferably the recess 47 and the second bead 46) are more reliably positioned radially outward of the tapered portion 25.

[0041] Furthermore, because the positioning annular portion 43 is brought into contact with the outer peripheral surface of the cylindrical member 30 over the entire circumference, the positioning annular portion 43 also functions as a sealing lip. That is, the internal space of the cylindrical member support through hole 13 in the first member 10 is isolated from the internal space of the cylindrical member accommodating through hole 23 in the second member 20 by the positioning annular portion 43, which is brought into contact with the cylindrical member 30. Therefore, the flow of fluid between the internal space of the cylindrical member support through hole 13 in the first member 10 and the internal space of the cylindrical member accommodating through hole 23 in the second member 20 is obstructed, further reducing leakage of fluid from inside the cylindrical member 30.

[0042] When the cylindrical member 30 is inserted into the cylindrical member accommodating through-hole 23, the cylindrical member 30 is moved downward in the figure. As a result, with the elastic portion 41 compressed along the axial direction, the positioning annular portion 43 is bent by the cylindrical member 30 and enters the interior of the tapered portion 25 of the cylindrical member accommodating through-hole 23, where it comes into contact with the tapered portion 25. The interior of the tapered portion 25 is a partial space of the cylindrical member accommodating through-hole 23 surrounded by the tapered portion 25, where the cylindrical member 30 is located. As a result, the positioning annular portion 43 is supported by the tapered portion 25 and the outer peripheral surface of the cylindrical member 30, preventing the elastic portion 41 of the gasket 40 from moving laterally. This allows the gasket 40 to stably exhibit sealing performance.

[0043] As shown in FIG. 1 , in this embodiment, the diameter D1 of the inner peripheral surface 43c of the annular portion in an uncompressed state is larger than the outer diameter D2 of the cylindrical member 30. However, the elastic portion 41 is constrained by the rigid portion 50 on the radially outer side. During use (when the gasket 40 is sandwiched between the first member 10 and the second member 20), the elastic portion 41 is compressed in the axial direction between the first member 10 and the second member 20, causing the elastic portion 41 to stretch radially inward. Therefore, as shown in FIG. 5 , the positioning annular portion 43 is brought into contact with the outer peripheral surface of the cylindrical member 30 over its entire circumference and is further bent by the cylindrical member 30 to enter the tapered portion 25. A seal ring 60 is fitted into the cylindrical member 30. Because both the positioning annular portion 43 and the seal ring 60 are made of an elastic material, the seal ring 60 smoothly passes through the positioning annular portion 43 when the cylindrical member 30 is inserted into the cylindrical member accommodating through-hole 23.

[0044] 2, when the elastic portion 41 is not compressed in the axial direction, the first annular surface 43a and the second annular surface 43b of the positioning annular portion 43 are perpendicular to the axial direction of the gasket 40 and parallel to each other. Therefore, when the cylindrical member 30 is inserted downward in the figure into the insertion hole 43d of the positioning annular portion 43, the cylindrical member 30 presses the first annular surface 43a of the positioning annular portion 43, bending the positioning annular portion 43 and easily inserting it into the tapered portion 25 of the second member 20. When the gasket 40 shown in FIG. 5 is used, the positioning annular portion 43 is bent, and the first annular surface 43a comes into surface contact with the outer peripheral surface of the cylindrical member 30, and the corners of the annular portion inner peripheral surface 43c come into contact with the tapered portion 25 along the entire circumference.

[0045] If the gap between the first annular surface 43a and the second annular surface 43b of the positioning annular portion 43 increases radially inward when the elastic portion 41 is not compressed axially, the problem shown in FIG. 6 may occur. In the state shown in FIG. 6, the gasket 40 is disposed between the first member 10 and the second member 20, but the first member 10 and the second member 20 are not fastened together, and the gasket 40 is subjected to only a small compressive force along the axial direction. However, even with a small compressive force, the positioning annular portion 43 stretches radially inward. Furthermore, the gasket 40, including the positioning annular portion 43, is eccentric to the left in the figure relative to the cylindrical member support through-hole 13 of the first member 10 and, ultimately, the cylindrical member 30. In this case, when the cylindrical member 30 is inserted downward into the insertion hole 43d of the positioning annular portion 43, depending on the inclination of the gasket 40 relative to the upper surface 21 of the second member 20 and / or the deformation of the positioning annular portion 43, the left portion of the lower edge of the cylindrical member 30 in the figure may come into contact with the annular portion inner surface 43c of the positioning annular portion 43. In this case, the left portion of the positioning annular portion 43 in the figure may bend toward the first member 10 rather than the second member 20. On the other hand, because the gasket 40 is eccentric to the left in the figure, the right portion of the positioning annular portion 43 in the figure is pushed by the cylindrical member 30 and bends toward the second member 20, causing the positioning annular portion 43 to twist. In this case, the function of the positioning annular portion 43 to position the gasket 40 and the function of the seal lip are both impaired. The embodiment can solve these problems.

[0046] In this embodiment, the rigid portion 50 of the gasket 40 has an insertion hole 51 into which a bolt 65 is inserted, so that the rigid portion 50 of the gasket 40, the first member 10, and the second member 20 can be fastened with the same bolt 65, thereby suppressing misalignment of the gasket 40 relative to the first member 10 and the second member 20 and preventing the first bead 45 and the second bead 46 of the elastic portion 41 from unintentionally penetrating into the interior of the tapered portion 25.

[0047] Fig. 7 is a cross-sectional view of a sealing structure according to a modification of the embodiment before assembly, and Fig. 8 is a cross-sectional view of the sealing structure of Fig. 7 after assembly. In this modification, the diameter D1 of the inner circumferential surface 43c of the annular portion in an uncompressed state is smaller than the outer diameter D2 of the cylindrical member 30. In this case as well, as shown in Fig. 8, the positioning annular portion 43 is brought into contact with the outer circumferential surface of the cylindrical member 30 over the entire circumference, and can be bent to enter the inside of the tapered portion 25.

[0048] In this modification, an X-ring seal ring 70 is used instead of the O-ring seal ring 60. The seal ring 70 is made of an elastic material, such as an elastomer containing rubber. The seal ring 70 is fitted into the circumferential groove 31 at the lower end of the cylindrical member 30. When the cylindrical member 30 is inserted into the cylindrical member accommodating through-hole 23, the seal ring 70 is positioned inside the cylindrical member accommodating through-hole 23 and compressed between the inner circumferential surface of the cylindrical member accommodating through-hole 23 and the outer circumferential surface of the cylindrical member 30. Therefore, the seal ring 70 closes the gap between the outer circumferential surface of the cylindrical member 30 and the inner circumferential surface of the cylindrical member accommodating through-hole 23, preventing or reducing leakage of fluid inside the cylindrical member 30 through this gap. When a refrigerant flows inside the cylindrical member 30, a preferred material for the seal ring 70 is, for example, HNBR or EPDM.

[0049] Furthermore, in this modification, the gasket 40 has a rigid portion 50A instead of the rigid portion 50. The rigid portion 50A does not have an insertion hole 51 through which the bolt 65 is inserted. The rigid portion 50A has, for example, an outer peripheral surface concentric with the elastic portion 41. As shown in FIG. 8 , the gasket 40 is disposed between the first member 10 and the second member 20, and the first member 10 and the second member 20 are fastened together by a bolt 65, which is a threaded member. The threaded portion of the bolt 65 is inserted into the fastener through hole 14 of the first member 10 and screwed into the threaded hole 24 of the second member 20. Preferably, the gasket 40 is first disposed between the first member 10 and the second member 20. Then, the cylindrical member 30 is inserted into the cylindrical member support through hole 13 and the cylindrical member accommodating through hole 23. Next, the first member 10 and the second member 20 are fastened together by the bolt 65, and the gasket 40 is compressed along the axial direction.

[0050] In this modified example, because the gasket 40 is not fastened by the bolts 65, there is a possibility that the gasket 40 may move laterally relative to the first member 10 and the second member 20 before being significantly compressed in the axial direction. However, the positioning annular portion 43 of the gasket 40 is disposed around the cylindrical member 30, and the relative position of the positioning annular portion 43 and therefore the entire gasket 40 with respect to the cylindrical member 30 is determined. Therefore, the cylindrical member 30 and the positioning annular portion 43 position the gasket 40 so that at least the first bead 45 (and more preferably the recess 47 and the second bead 46) are positioned radially outward of the tapered portion 25 of the cylindrical-member-accommodating through-hole 23. Therefore, as long as an operator pays attention when fastening the bolts 65, it is possible to prevent the first bead 45 and the second bead 46 of the elastic portion 41 from unintentionally entering the interior of the tapered portion 25.

[0051] 9 shows a gasket 75 before assembly of a sealing structure according to another modified embodiment. In this gasket 75, when the elastic portion 41 is not compressed in the axial direction, the outer portion 42 of the elastic portion 41 has a flat first surface 42A. That is, the first surface 42A facing the lower surface 12 of the first member 10 does not have beads 45, 46 or recesses 47 formed thereon. On the other hand, the second surface 42B facing the upper surface 21 of the second member 20 has beads 45, 46 and recesses 47 formed thereon.

[0052] Although not shown, the gasket 75 is disposed between the first member 10 and the second member 20, and is compressed along the axial direction of the cylindrical member accommodating through-hole 23, similar to the gasket 40 shown in FIG. 8 . A first surface 42A of an outer portion 42 of the elastic portion 41 is brought into contact (line contact or surface contact) with the lower surface 12 of the first member 10, and a second surface 42B of the outer portion 42 is brought into contact (line contact or surface contact) with the upper surface 21 of the second member 20. A tapered portion 25 is formed in the cylindrical member accommodating through-hole 23 of the second member 20. A positioning annular portion 43 disposed inside the outer portion 42 extends toward the cylindrical member 30, and is disposed around the cylindrical member 30 inserted into the cylindrical member support through-hole 13 and the cylindrical member accommodating through-hole 23. That is, the positioning annular portion 43 of the gasket 75 is disposed around the cylindrical member 30, and the relative position of the positioning annular portion 43 and therefore the entire gasket 75 with respect to the cylindrical member 30 is determined. As a result, the cylindrical member 30 and the positioning annular portion 43 position the gasket 75 so that at least the first bead 45 (more preferably the recessed portion 47 and the second bead 46) are positioned radially outside the tapered portion 25 of the cylindrical member accommodating through-hole 23.

[0053] When the elastic portion 41 is not compressed in the axial direction, the positioning annular portion 43 has a tapered shape that tapers radially inward so that the gap between the first annular surface 43a and the second annular surface 43b becomes smaller radially inward. Therefore, when the cylindrical member 30 is inserted downward into the positioning annular portion 43, the cylindrical member 30 presses the first annular surface 43a, bending the positioning annular portion 43 and easily inserting it into the tapered portion 25 of the second member 20.

[0054] The gasket 75 has a rigid portion 50B instead of the rigid portion 50. The rigid portion 50B has a circumferential groove 52 on the surface that contacts the lower surface 12 of the first member 10 and a circumferential groove 53 on the surface that contacts the upper surface 21 of the second member 20. As shown in FIG. 9 , when the elastic portion 41 is not compressed along the axial direction, the thickness T1 of the elastic portion 41 in the first bead 45 is greater than the maximum thickness T3 of the rigid portion 50. Although not absolutely necessary, in this state, the thickness T2 of the elastic portion 41 in the second bead 46 is preferably greater than the thickness T3 of the rigid portion 50. Furthermore, although not absolutely necessary, in this state, the thickness T4 of the elastic portion 41 in the recess 47 is preferably greater than the thickness T3 of the rigid portion 50. The sum of the crushing allowances (deformation amounts) of the elastic portion 41 in the first bead 45 relative to the first member 10 and the second member 20 is T1-T3. The sum of the crushing allowances (deformation amounts) of the elastic portion 41 in the second bead 46 for the first member 10 and the second member 20 is T2-T3. The sum of the crushing allowances (deformation amounts) of the elastic portion 41 in the recess 47 for the first member 10 and the second member 20 is T4-T3.

[0055] 10 shows a gasket 80 after assembly of a sealing structure according to yet another modified example of the embodiment. In a state compressed between the lower surface 12 of the first member 10 and the upper surface 21 of the second member 20, the positioning annular portion 43 of the gasket 80 is not bent by the cylindrical member 30 and does not enter the tapered portion 25 of the cylindrical member accommodating through-hole 23. In this state, the diameter of the annular portion inner circumferential surface 43c of the positioning annular portion 43 is slightly larger than the outer diameter D2 of the cylindrical member 30.

[0056] In this modified example, the positioning annular portion 43 of the gasket 80 does not function as a sealing lip, but is arranged around the cylindrical member 30. That is, the positioning annular portion 43 of the gasket 80 is arranged around the cylindrical member 30, and the relative position of the positioning annular portion 43 and therefore the entire gasket 80 with respect to the cylindrical member 30 is determined. As a result, the cylindrical member 30 and the positioning annular portion 43 position the gasket 80 so that at least the first bead 45 (and more preferably the recessed portion 47 and the second bead 46) are positioned radially outward of the tapered portion 25 of the cylindrical-member-accommodating through-hole 23. Therefore, the gasket 80 can stably exhibit sealing properties.

[0057] 11 shows a sealing structure according to yet another modified example of the embodiment after assembly. This modified example has a first member 82 instead of the first member 10 and the cylindrical member 30. The first member 82 has a plate portion 83 and a cylindrical portion 84 joined to the plate portion 83. The cylindrical portion 84 extends above and below the plate portion 83 in the figure. Therefore, the first member 82 is equivalent to the first member 10 and the cylindrical member 30 of the embodiment being fixed together.

[0058] The plate portion 83 has a flat upper surface 83a and a flat lower surface (first flat surface) 83b, and the gasket 40 is interposed between the lower surface 83b of the plate portion 83 and the upper surface 21 of the second member 20, and is disposed radially outward of the cylindrical portion 84 (surrounding the cylindrical portion 84). The plate portion 83 is formed with a fastener through hole 14 into which the above-mentioned bolt 65 is inserted, and the lower end of the cylindrical portion 84 is formed with a circumferential groove 31 into which the seal ring 60 is fitted. Other features are the same as those of the sealing structure of the embodiment.

[0059] The gasket 40 is first placed so as to contact the upper surface 21 of the second member 20. Then, the cylindrical portion 84 is inserted into the cylindrical member accommodating through hole 23 of the second member 20, and the lower surface 83b of the plate portion 83 is brought into contact with the gasket 40. Next, the plate portion 83, the second member 20, and the gasket 40 are fastened together with the bolts 65, and the gasket 40 is compressed along the axial direction.

[0060] 12 shows a sealing structure according to yet another modified example of the embodiment after assembly. This modified example has a screw member (first member) 90 instead of the first member 10 and the cylindrical member 30. The screw member 90 has a head portion 91 and a thread portion 92.

[0061] The head 91 has a flat upper surface 91a and a flat lower surface (first flat surface) 91b. The lower surface 91b is parallel to the upper surface 91a, but does not have to be parallel. A threaded portion 92 is integrally connected to the lower surface 91b.

[0062] The second member 20 of this modified example has a screw hole (hole portion) 26 into which the threaded portion 92 of the screw member 90 is inserted and fastened, instead of the cylindrical member accommodating through-hole 23 into which the cylindrical member 30 is inserted. Furthermore, the second member 20 does not have a screw hole 24 into which the bolt 65 is screwed. Other features of the second member 20 are the same as those of the second member 20 of the embodiment. The screw hole 26 has a tapered portion 25. The tapered portion 25 is formed in an annular shape at the upper end of the screw hole 26 that opens at the upper surface 21, and has a diameter that decreases with increasing distance from the upper surface 21. It can also be said that the tapered portion 25 has a diameter that increases with increasing distance from the upper surface 21.

[0063] A fluid is stored in the space below the threaded portion 92 in the figure.

[0064] The gasket 40 is interposed between the lower surface 91b of the head 91 of the screw member 90 and the upper surface 21 of the second member 20, and is disposed radially outside the threaded portion 92 of the screw member 90 (surrounding the threaded portion 92). The gasket 40 of this modified example is the same as the gasket 40 of the modified example shown in FIG.

[0065] The threaded portion 92 of the screw member 90 is screwed into the threaded hole 26 of the second member 20 and fastened, and the elastic portion 41 of the gasket 40 is compressed along the axial direction of the threaded hole 26 between the lower surface 91b of the head 91 of the screw member 90 and the upper surface 21 of the second member 20, and a first surface 42A (see FIG. 2 ) of an outer portion 42 of the elastic portion 41 is brought into contact (line contact or surface contact) with the lower surface 91b of the head 91, and a second surface 42B of the outer portion 42 is brought into contact (line contact or surface contact) with the upper surface 21 of the second member 20. Therefore, even if fluid inside the space below the threaded portion 92 leaks into the gap between the outer peripheral surface of the threaded portion 92 and the inner peripheral surface of the threaded hole 26, the elastic portion 41 prevents or reduces further leakage of the fluid through the gap between the head 91 and the second member 20. The rigid portion 50 of the gasket 40 is brought into contact with the lower surface 91 b of the head portion 91 and the upper surface 21 of the second member 20 , and functions as a spacer that ensures a gap between the head portion 91 and the second member 20 .

[0066] Preferably, first, the gasket 40 is placed between the first member 10 and the second member 20. Then, the threaded portion 92 of the screw member 90 is fastened to the screw hole 26, and the gasket 40 is compressed along the axial direction.

[0067] In this modified example, when the elastic portion 41 is not compressed in the axial direction, the thickness T1 of the elastic portion 41 at the first bead 45 (see FIG. 2 ) and the thickness T2 of the elastic portion 41 at the second bead 46 are greater than the thickness T3 of the rigid portion 50, and preferably the thickness T4 of the elastic portion 41 at the recess 47 is greater than the thickness T3 of the rigid portion 50. At least the first bead 45 of the elastic portion 41 is compressed and flattened in the axial direction between the lower surface 91 b of the head 91 of the screw member 90 and the upper surface 21 of the second member 20, radially outside the tapered portion 25 of the screw hole 26. Preferably, the second bead 46 is also compressed and flattened in the axial direction between the lower surface 91 b of the head 91 of the screw member 90 and the upper surface 21 of the second member 20, radially outside the tapered portion 25 of the screw hole 26. More preferably, the recess 47 is also compressed and flattened along the axial direction between the lower surface 91b of the head 91 of the screw member 90 and the upper surface 21 of the second member 20, radially outside the tapered portion 25 of the screw hole 26. Therefore, the gasket 40 is compressed with a large crushing allowance (amount of deformation) without being affected by manufacturing errors or tilt of the tapered portion 25, and the gasket 40 can stably exhibit sealing properties.

[0068] Furthermore, the positioning annular portion 43 (see FIG. 2 ) of the elastic portion 41 extends toward the threaded portion 92 of the screw member 90 and is disposed around the threaded portion 92 screwed into the screw hole 26. That is, the positioning annular portion 43 of the gasket 40 is disposed around the threaded portion 92, and the relative position of the positioning annular portion 43 and therefore the entire gasket 40 with respect to the threaded portion 92 is determined. As a result, the threaded portion 92 and the positioning annular portion 43 position the gasket 40 so that at least the first bead 45 (more preferably, the recessed portion 47 and the second bead 46) is positioned radially outside the tapered portion 25 of the screw hole 26. The positioning annular portion 43 disposed around the threaded portion 92 restricts lateral movement of the gasket 40, so that at least the first bead 45 (more preferably, the recessed portion 47 and the second bead 46) is reliably positioned outside the tapered portion 25 of the screw hole 26. Therefore, the gasket 40 can stably exhibit sealing performance.

[0069] With the elastic portion 41 of the gasket 40 compressed in the axial direction, the positioning annular portion 43 is brought into contact with the outer peripheral surface of the threaded portion 92 over the entire circumference. Therefore, lateral movement of the gasket 40 between the head 91 of the threaded member 90 and the second member 20 is further restricted, and the gasket 40 is positioned so that at least the first bead 45 (and more preferably the recess 47 and the second bead 46) are more reliably positioned radially outward of the tapered portion 25.

[0070] Furthermore, because the positioning annular portion 43 is brought into contact with the outer peripheral surface of the threaded portion 92 over the entire circumference, the positioning annular portion 43 also functions as a sealing lip. That is, the space on the head 91 side of the screw member 90 is isolated from the internal space of the screw hole 26 of the second member 20 by the positioning annular portion 43, which is brought into contact with the threaded portion 92. Therefore, the flow of fluid between the space on the head 91 side of the screw member 90 and the internal space of the screw hole 26 of the second member 20 is obstructed, further reducing fluid leakage.

[0071] When the threaded portion 92 is fastened to the threaded hole 26, the threaded portion 92 is moved downward, and with the elastic portion 41 compressed in the axial direction, the positioning annular portion 43 is bent by the threaded portion 92 and enters the tapered portion 25 of the threaded hole 26, coming into contact with the tapered portion 25. As a result, the positioning annular portion 43 is supported by the outer peripheral surfaces of the tapered portion 25 and the threaded portion 92, and the elastic portion 41 of the gasket 40 is prevented from moving laterally. This allows the gasket 40 to stably exhibit sealing performance.

[0072] Although the present invention has been shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that changes may be made in form and detail without departing from the scope of the invention as set forth in the appended claims. Such changes, modifications and alterations are intended to be included within the scope of the invention.

[0073] For example, the bolt 65 may be replaced with a fastener having a different rod shape, such as a screw, a rivet, or a split pin other than a bolt.

[0074] The above-described seal ring 60 is an O-ring and the seal ring 70 is an X-ring, but other types of seal rings such as D-rings, T-rings, etc. may also be used. Also, the seal ring 60 or 70 may be omitted.

[0075] The gaskets 40, 75, and 80 have been illustrated and described with two insertion holes 51 formed at equal intervals on both sides of the insertion hole 43d. By forming the insertion holes 43d at equal intervals on both sides of the insertion hole 43d, the fastening force of the fastener 65 can be evenly transmitted to the elastic portion 41 from both sides of the insertion hole 43d, thereby achieving stable sealing. However, as long as the required sealing force can be ensured, the positions of the two insertion holes 51 do not necessarily need to be formed at equal intervals from the insertion hole 43d. Alternatively, although not shown, the insertion holes 51 may be formed on only one side of the insertion hole 43d. In this case, the area of ​​the rigid portion 50, 50A, and 50B on the side where the insertion hole 51 is not formed can be reduced, and the areas of the first member 10, 90 and the second member 20 can also be reduced accordingly, thereby reducing the size of the entire sealing structure.

[0076] The gaskets 40, 80 of the present invention are preferably configured so that the shapes of the upper and lower surfaces (front and back surfaces) of the gasket are plane symmetrical, as shown in Fig. 2. When applying the gaskets 40, 80 to the sealing structure of the present invention, there is no need to distinguish between the upper and lower surfaces (front and back surfaces), which improves productivity.

[0077] The following describes the procedure for assembling the gasket 40, 75, 80 and the seal ring 60, 70 to the cylindrical portion 30, 84. In one example, the seal ring 60, 70 is first fitted into the circumferential groove 31 of the cylindrical portion 30, 84. Next, the tip of the cylindrical portion 30, 84 is inserted into the gasket 40, 75, 80, and then the gasket may be moved so that the insertion hole portion 43d of the gasket passes over the outer edge of the seal ring 60, 70, thereby bringing the gasket close to the underside 12, 83b of the first member 10, 82 (first temporary assembly method). As already described, the gasket 40, 75, 80 has the positioning annular portion 43 that is part of the elastic portion 41 and extends toward the center of the insertion hole portion 43d. Therefore, the gasket can be moved so as to pass over the seal ring 60, 70 attached to the circumferential groove 31 while deforming the positioning annular portion 43.

[0078] In another example of the assembly order, first, the cylindrical portion 30, 84 may be inserted into the gasket 40, 75, 80, and then the gasket may be moved to a position closer to the underside 12, 83 b of the first member 10, 82 than the circumferential groove 31, and then the seal ring 60, 70 may be fitted into the circumferential groove 31 of the cylindrical portion 30, 84 (second temporary assembly method). According to these two examples, if the diameter D1 of the annular portion inner circumferential surface 43 c of the elastic portion 41 of the gasket 40, 75, 80 is smaller than the outer diameter of the seal ring 60, 70, it is possible to effectively prevent the gasket 40, 75, 80 from falling off the cylindrical portion 30, 84.

[0079] The above-described embodiments and modifications may be combined unless they are inconsistent.

[0080] Aspects of the invention are also described in the following numbered clauses. Clause 1. A first member having a first planar surface; a second member having a second flat surface facing the first flat surface and a hole portion having a circular cross section extending in a direction perpendicular to the second flat surface, the hole portion having a tapered portion formed in an axial direction of the hole portion with a diameter increasing as the hole portion approaches the second flat surface; a cylindrical portion or a threaded portion to be inserted into the hole; a gasket disposed between the first flat surface and the second flat surface and radially outward of the cylindrical portion or the threaded portion; Equipped with The gasket has an elastic portion made of an elastic material, the elastic portion being compressed along the axial direction between the first flat surface and the second flat surface, and a rigid portion made of a rigid material, the rigid portion being fixed to an outer circumferential surface of the elastic portion and being brought into contact with the first flat surface and the second flat surface, the elastic portion has a first surface that is brought into contact with the first flat surface, a second surface that is brought into contact with the second flat surface, an insertion hole portion (43d) through which the cylindrical portion or the threaded portion is inserted, a first annular bead formed on at least the second surface, and a second annular bead formed on at least the second surface concentrically with the first bead, the second bead is located radially outward of the insertion hole portion, the first bead is located radially outward of the second bead, When the elastic portion is not compressed along the axial direction, the thickness of the elastic portion at the first bead and the second bead is greater than the maximum thickness of the rigid portion; The first bead is compressed along the axial direction between the first flat surface and the second flat surface on the radially outer side of the tapered portion. Sealed structure.

[0081] Clause 2. The second bead is compressed along the axial direction between the first flat surface and the second flat surface on the radially outer side of the tapered portion. Sealing structure as described in clause 1. According to this clause, in addition to the first bead on the radially outer side, the second bead on the radially inner side is also compressed between the first flat surface and the second flat surface on the radially outer side of the tapered portion. Therefore, the first bead and the second bead are compressed with a large crushing allowance (deformation amount) without being affected by manufacturing errors or inclination of the tapered portion, and the gasket can exhibit stable sealing performance.

[0082] Clause 3. The elastic portion has a recess between the first bead and the second bead, When the elastic portion is not compressed along the axial direction, the thickness of the elastic portion at the recess is greater than the maximum thickness of the rigid portion, The recess is compressed along the axial direction between the first flat surface and the second flat surface on the radially outer side of the tapered portion. Sealing structure as described in clause 2. According to this clause, not only the first bead and the second bead, but also the recess between these beads is compressed between the first flat surface and the second flat surface on the radially outer side of the tapered portion, so the elastic portion is compressed with a large crushing allowance (deformation amount) without being affected by manufacturing errors or inclination of the tapered portion, allowing the gasket to stably exhibit sealing properties. Furthermore, even if the second bead is damaged or foreign matter gets inside the recess, the gasket can stably exhibit sealing properties.

[0083] Clause 4. The elastic portion has a positioning annular portion that extends radially inward of the second bead toward the cylindrical portion or the threaded portion and positions the gasket so that at least the first bead is located radially outward of the tapered portion. A sealing structure according to any one of clauses 1 to 3. According to this clause, the positioning annular portion of the elastic portion disposed between the first and second members is disposed around the cylindrical portion or the threaded portion, so that lateral movement of the gasket between the first and second members is restricted and the gasket is positioned so that at least the first bead is reliably positioned radially outward of the tapered portion, thereby enabling the gasket to stably exhibit sealing performance.

[0084] Clause 5. When the elastic portion is compressed along the axial direction, the positioning annular portion of the elastic portion is brought into contact with the outer peripheral surface of the cylindrical portion or the threaded portion over the entire circumference. Sealing structure as described in clause 4. According to this clause, the positioning annular portion of the elastic portion compressed between the first and second members is brought into contact with the cylindrical portion or the threaded portion, thereby further restricting lateral movement of the gasket between the first and second members and positioning the gasket so that at least the first bead is more reliably positioned radially outward of the tapered portion. Furthermore, the space on the first member side is isolated from the internal space of the hole of the second member by the positioning annular portion brought into contact with the cylindrical portion or the threaded portion. Therefore, fluid communication between the space on the first member side and the internal space of the hole of the second member is inhibited.

[0085] Clause 6. With the elastic portion compressed along the axial direction, the positioning annular portion enters the inside of the tapered portion and is brought into contact with the tapered portion. Sealing structure as described in clause 5. According to this clause, the positioning annular portion is supported by the outer peripheral surface of the tapered portion and the cylindrical portion or the threaded portion, preventing the elastic portion of the gasket from moving laterally, thereby enabling the gasket to stably exhibit sealing properties.

[0086] Clause 7. When the elastic portion is not compressed along the axial direction, the positioning annular portion has an inner circumferential surface that defines the insertion hole portion, a first annular surface facing the first flat surface, and a second annular surface facing the second flat surface, When the elastic portion is not compressed along the axial direction, the first and second annular surfaces are perpendicular to the axial direction and parallel to each other, or are inclined so that the distance between the first and second annular surfaces becomes smaller toward the radially inner side. Sealing structure as described in clause 6. According to this clause, when the cylindrical portion or the threaded portion is inserted into the positioning annular portion, the cylindrical portion or the threaded portion presses against the first annular surface of the positioning annular portion, bending the positioning annular portion and making it easier for it to penetrate into the tapered portion of the hole portion of the second member.

[0087] Clause 8. A sealing structure according to any one of clauses 1 to 7, wherein the cylindrical portion is inserted into the hole, Further provided is a rod-shaped fastener that fastens the first member and the second member, The rigid portion of the gasket has an insertion hole into which the fastener is inserted. Sealed structure. According to this clause, the rigid portion of the gasket, the first member, and the second member can be fastened with the same fastener, which suppresses misalignment of the gasket relative to the first member and the second member and prevents at least the first bead of the elastic portion from unintentionally penetrating inside the tapered portion.

[0088] Clause 9. A sealing structure according to any one of clauses 1 to 8, wherein the cylindrical portion is inserted into the hole, a seal ring disposed in the hole of the second member and compressed between an inner circumferential surface of the hole of the second member and an outer circumferential surface of the cylindrical portion; Sealed structure. According to this clause, the seal ring closes the gap between the outer peripheral surface of the cylindrical portion and the inner peripheral surface of the hole portion of the second member, and prevents or reduces fluid from leaking into this gap. [Explanation of symbols]

[0089] 10 First member 12 Bottom surface (first flat surface) 20 Second member 21 Top surface (second flat surface) 23 Cylindrical member receiving through hole (hole portion) 25 Tapered section 26 screw hole (hole) 30 Cylindrical member (cylindrical part) 31 Circumferential groove 40,75,80 gasket 41 Elastic part 42 Outer part 42A First Surface 42B Second Surface 43 Positioning ring 43a First torus 43b Second torus 43c Inner surface of the annular part 45 First Bead 46 Second Bead 47 Recess 50,50A,50B Rigid part 51 Insertion hole 60,70 Seal ring 65 bolts (fasteners) 82 First member 83 Board part 83b Lower surface (first flat surface) 84 Cylindrical part 90 Screw member (first member) 91 Head 92 Threaded part 91b Lower surface (first flat surface)

Claims

1. a first member (10, 90) having a first flat surface (12, 91b); a second member (20) having a second flat surface (21) facing the first flat surface and a hole (23, 26) extending in a direction perpendicular to the second flat surface and having a circular cross section, the hole having a tapered portion (25) formed in the axial direction of the hole, the diameter of which increases as the hole approaches the second flat surface; a cylindrical portion (30) or a threaded portion (92) to be inserted into the hole; a gasket (40, 75, 80) disposed between the first flat surface and the second flat surface and radially outward of the cylindrical portion or the threaded portion; Equipped with The gasket has an elastic portion (41) made of an elastic material and compressed along the axial direction between the first flat surface and the second flat surface, and rigid portions (50, 50A, 50B) made of a rigid material and fixed to an outer circumferential surface of the elastic portion and brought into contact with the first flat surface and the second flat surface, The elastic portion (41) has a first surface (42A) that comes into contact with the first flat surface, a second surface (42B) that comes into contact with the second flat surface, an insertion hole portion (43d) through which the cylindrical portion or the threaded portion is inserted, a first annular bead (45) formed on at least the second surface, and a second annular bead (46) formed on at least the second surface concentrically with the first bead, the second bead is located radially outward of the insertion hole portion, the first bead is located radially outward of the second bead, When the elastic portion is not compressed along the axial direction, the thickness of the elastic portion (41) at the first bead (45) and the second bead (46) is greater than the maximum thickness of the rigid portion (50, 50A, 50B); The first bead (45) is compressed along the axial direction between the first flat surface (12, 91b) and the second flat surface (21) on the radially outer side of the tapered portion (25). Sealed structure.

2. The second bead (46) is compressed along the axial direction between the first flat surface (12, 91b) and the second flat surface (21) on the radially outer side of the tapered portion (25). The sealing structure according to claim 1 .

3. The elastic portion (41) has a recess (47) between the first bead and the second bead, When the elastic portion is not compressed along the axial direction, the thickness of the elastic portion at the recess is greater than the maximum thickness of the rigid portion, The recess is compressed along the axial direction between the first flat surface and the second flat surface on the radially outer side of the tapered portion. The sealing structure according to claim 2 .

4. The elastic portion (41) has a positioning annular portion (43) that extends radially inward of the second bead toward the cylindrical portion or the threaded portion and positions the gasket so that at least the first bead is located radially outward of the tapered portion. The sealing structure according to any one of claims 1 to 3.

5. With the elastic portion (41) compressed along the axial direction, the positioning annular portion (43) of the elastic portion is brought into contact with the outer peripheral surface of the cylindrical portion or the threaded portion over the entire circumference. The sealing structure according to claim 4.

6. With the elastic portion compressed along the axial direction, the positioning annular portion (43) enters the inside of the tapered portion and is brought into contact with the tapered portion. The sealing structure according to claim 5.

7. When the elastic portion is not compressed along the axial direction, the positioning annular portion has an inner peripheral surface (43c) that defines the insertion hole portion, a first annular surface (43a) that faces the first flat surface, and a second annular surface (43b) that faces the second flat surface, When the elastic portion is not compressed along the axial direction, the first annular surface and the second annular surface are perpendicular to the axial direction and parallel to each other, or are inclined so that the distance between the first annular surface and the second annular surface becomes smaller toward the radially inner side. The sealing structure according to claim 6.

8. 4. The sealing structure according to claim 1, wherein the cylindrical portion (30) is inserted into the hole (25), The device further includes a rod-shaped fastener (65) for fastening the first member and the second member together, The rigid portion (50) of the gasket has an insertion hole (51) into which the fastener is inserted. Sealed structure.

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