Gaskets and sealing structures

Abstract

To make a gasket surely seal two members even if holes of the two members are decentered.SOLUTION: A gasket is interposed between a pipe part having a first hole and a hollow member having a second hole, and compressed between the pipe part and the hollow member. The gasket has an elastic portion which is formed of rubber. The elastic portion has a cylinder part which is pressure-inserted into the first hole of the pipe part, and a flange interposed between the pipe part and the hollow member. An external peripheral face of the cylinder part has a protrusive annular part protruding to the outside in a radial direction, and at least the protrusive annular part face-contacts with an internal peripheral face of the first hole. The flange is arranged at the cylinder part coaxially therewith, and has an outside protrusion annular part having an external peripheral face having a large diameter larger than a maximum outside diameter of the external peripheral face of the cylinder part, an inside protrusion annular part having an internal peripheral face having an inside diameter smaller than a minimum inside diameter of an internal peripheral face of the cylinder part, and an end face having a portion face-contacting with the hollow member. The inside protrusion annular part overlaps the outside protrusion annular part in the radial direction and the end face extends from the outside protrusion annular part to the inside protrusion annular part.SELECTED DRAWING: Figure 2

Description

Technical Field

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[0001] The present invention relates to gaskets and sealing structures.

Background Art

[0002] Patent Document 1 discloses a gasket that is interposed between two members each having a hole and is compressed between them.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Even if the holes of the two members are eccentric, it is preferable that the gasket can surely seal both of them.

[0005] Therefore, the present invention provides a gasket that can surely seal two members even if the holes of the two members are eccentric, and a sealing structure having this gasket.

Means for Solving the Problems

[0006] One aspect of the present invention provides a gasket interposed between a tubular portion having a first hole and a hollow member having a second hole, and compressed between the end face of the tubular portion and the hollow member. The gasket has an elastic portion formed from rubber. The elastic portion is press-fitted into the first hole of the tube portion and has an outer circumferential surface and an inner circumferential surface, the outer circumferential surface having a convex ring portion projecting radially outward at the axial center, and at least the convex ring portion making surface contact with the inner circumferential surface of the first hole; and a flange integrally connected to the cylindrical portion and arranged concentrically with the cylindrical portion, interposed between the end face of the tube portion and the hollow member, having an outer protruding ring portion having an outer circumferential surface having an outer diameter larger than the maximum outer diameter of the outer circumferential surface of the cylindrical portion, an inner protruding ring portion having an inner circumferential surface having an inner diameter smaller than the minimum inner diameter of the inner circumferential surface of the cylindrical portion, and an end face having a portion that makes surface contact with the hollow member, the inner protruding ring portion overlapping the outer protruding ring portion radially, and the end face extending from the outer protruding ring portion to the inner protruding ring portion.

[0007] In this embodiment, the cylindrical portion of the elastic part of the gasket, which is made of rubber, is press-fitted into the first hole of the pipe, so that at least the convex ring portion of the outer circumferential surface of the cylindrical portion makes surface contact with the inner circumferential surface of the first hole. The flange of the elastic part of the gasket is interposed between the end face of the pipe and the hollow member, so that at least a portion of the end face of the flange makes surface contact with the hollow member. The flange has an outer protruding ring portion and an inner protruding ring portion, the outer protruding ring portion has an outer diameter larger than the maximum outer diameter of the outer circumferential surface of the cylindrical portion, and the inner protruding ring portion has an inner diameter smaller than the minimum inner diameter of the inner circumferential surface of the cylindrical portion, and the end face of the flange extends from the outer protruding ring portion to the inner protruding ring portion. Because the flange has such a large end face, it makes reliable surface contact with the hollow member. Therefore, even if the second hole of the hollow member is eccentric with respect to the first hole of the pipe, the gasket can reliably seal the pipe and the hollow member. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view showing a part of the sealing structure according to the first embodiment of the present invention. [Figure 2] This is a cross-sectional view of a gasket in an uncompressed state (non-use state) used in a sealing structure according to the first embodiment. [Figure 3] Figure 1 is a cross-sectional view showing the sealed structure and the gasket in an uncompressed state. [Figure 4] This is a cross-sectional view showing a sealing structure according to the first embodiment. [Figure 5] This is a cross-sectional view of a gasket used in a sealing structure according to a second embodiment of the present invention. [Figure 6] This is a cross-sectional view showing a sealing structure according to the second embodiment. [Figure 7] This is a cross-sectional view of a gasket used in a sealing structure according to a third embodiment of the present invention. [Figure 8] This is a cross-sectional view showing a sealing structure according to the third embodiment. [Figure 9] This is a cross-sectional view of a gasket according to a modified example of the first embodiment. [Figure 10] This is a cross-sectional view of a gasket according to another modification of the first embodiment. [Figure 11] This is a cross-sectional view of a gasket according to another modification of the first embodiment. [Figure 12] This is a cross-sectional view of a gasket according to another modification of the first embodiment. [Figure 13] This is a cross-sectional view of a gasket according to another modification of the first embodiment. [Modes for carrying out the invention]

[0009] Various embodiments of the present invention will be described below with reference to the attached drawings. The scale of the drawings is not necessarily accurate, and some features may be exaggerated or omitted.

[0010] First Embodiment As shown in Figure 1, the sealing structure according to the first embodiment of the present invention is applied to a pipe structure 10 and a plurality of hollow members 20. The pipe structure 10 is formed from a rigid material, such as metal or resin, and has a main pipe section 11 and a plurality of branch pipe sections 12 connected to the main pipe section 11.

[0011] Each hollow member 20 is also formed of a rigid material, such as metal or resin. The hollow member 20 may be, for example, a container or a pipe connected to the container, and the pipe structure 10 may be used to discharge air or gas from each hollow member 20 or to feed air or gas into the hollow member 20. Alternatively, the hollow member 20 may be a pipe for transporting water or oil, and the pipe structure 10 may be used to discharge water or oil from each hollow member 20 or to feed water or oil into the hollow member 20.

[0012] FIG. 1 shows only two branch pipe portions 12 and two hollow members 20, but more branch pipe portions 12 and hollow members 20 may be provided.

[0013] The plurality of branch pipe portions 12 are arranged at intervals parallel to each other, and the plurality of hollow members 20 are arranged at intervals.

[0014] Each branch pipe portion 12 has a first end face 14 and a first hole 13. The first end face 14 faces the hollow member 20.

[0015] The first hole 13 has a small-diameter hole portion 13a, a large-diameter hole portion 13b, and a step portion 13c. The small-diameter hole portion 13a communicates with the hole 11a of the main pipe portion 11. The large-diameter hole portion 13b has a diameter larger than that of the small-diameter hole portion 13a and is disposed closer to the first end face 14 than the small-diameter hole portion 13a. The step portion 13c connects the small-diameter hole portion 13a and the large-diameter hole portion 13b.

[0016] Each hollow member 20 has a second end face 21 and a second hole 22. The second end face 21 faces the first end face 14 of the branch pipe portion 12. An annular ridge 23 surrounding the second hole 22 over the entire circumference is formed on the second end face 21. The ridge 23 is concentric with the second hole 22. In the figure, the ridge 23 has a substantially rectangular cross section, and the upper surface of the ridge 23 is flat, but does not necessarily have to be flat.

[0017] The second hole 22 communicates with the first hole 13 of the branch pipe section 12. The second hole 22 has a diameter that is smaller than the diameter of the large-diameter hole section 13b but larger than the diameter of the small-diameter hole section 13a.

[0018] Since the multiple branch pipe sections 12 are connected to the main pipe section 11, they do not move relative to each other. On the other hand, the multiple hollow members 20 are arranged such that the spacing between the central axes of the second holes 22 can change. In this embodiment, intervening members 30 are interposed between the hollow members 20. Due to the dimensional accuracy of the intervening members 30 and / or the deformation of the intervening members 30, the spacing between the second holes 22 of the multiple hollow members 20 is unstable. The intervening members 30 are formed from a material that is softer than the material of the hollow members 20, such as resin, and have less rigidity than the hollow members 20. Therefore, especially when compressed laterally, the spacing between the multiple hollow members 20 is unstable due to the deformation of the intervening members 30.

[0019] However, the present invention is not limited to environments in which the intervening member 30 is placed between the hollow members 20. Even when there is no intervening member 30 and the hollow members 20 are in contact with each other, the spacing between the second holes 22 of the multiple hollow members 20 may not be stable due to the dimensional accuracy of the hollow members 20.

[0020] As shown in Figure 4, the sealing structure according to the embodiment further comprises a plurality of gaskets 40. Each gasket 40 seals the space between one of the branch pipe sections 12 and one of the hollow members 20. That is, each gasket 40 is interposed between the branch pipe section 12 and the hollow member 20 and compressed between them.

[0021] As shown in Figure 2, the gasket 40 has an elastic portion 41 formed from solid rubber and a reinforcing ring 42 that reinforces the elastic portion 41. "Solid" means that there are no air bubbles or that air bubbles are not intentionally present, and "solid rubber" means that foamed rubber in which air bubbles are intentionally present is excluded. However, the elastic portion 41 may be made of foamed rubber.

[0022] The elastic portion 41 has a cylindrical portion 43 and a flange 44 that are integrally formed. The flange 44 is positioned concentrically with the cylindrical portion 43. When the gasket 40 is used, the cylindrical portion 43 is positioned on the branch pipe portion 12 side, and the flange 44 is positioned on the hollow member 20 side.

[0023] The cylindrical portion 43 is press-fitted (tightly fitted) into the large-diameter hole 13b of the first hole 13 of the branched pipe portion 12. The cylindrical portion 43 has a substantially cylindrical shape with a bulge in the axial center and has an end face 43a, an outer circumferential surface 43b, and an inner circumferential surface 43c.

[0024] When the cylindrical portion 43 is not compressed, the end face 43a is a flat surface perpendicular to the axial direction of the gasket 40. The end face 43a is in surface contact with the stepped portion 13c of the first hole 13 of the branch pipe portion 12. The outer end of the end face 43a is connected to the outer circumferential surface 43b via a curved surface 43d, and the inner end of the end face 43a is connected to the inner circumferential surface 43c via a curved surface 43e.

[0025] In its uncompressed state, the outer circumferential surface 43b has a substantially cylindrical shape with a bulge in the axial center. Specifically, the outer circumferential surface 43b has a convex ring portion 43f projecting radially outward at its axial center. In the uncompressed state of the cylindrical portion 43, the convex ring portion 43f is cylindrical with a uniform diameter. By press-fitting the cylindrical portion 43 into the large-diameter hole portion 13b of the first hole 13, at least the convex ring portion 43f of the outer circumferential surface 43b comes into surface contact with the inner circumferential surface of the large-diameter hole portion 13b of the first hole 13 of the branched pipe portion 12. Other parts of the outer circumferential surface 43b, for example, most of the outer circumferential surface 43b may also come into surface contact with the large-diameter hole portion 13b of the first hole 13.

[0026] In its uncompressed state, the outer surface 43b further has an inclined portion 43g, a cylindrical portion 43h, and an inclined portion 43i. The inclined portion 43g is located between the convex ring portion 43f and the end face 43a (more precisely, the curved surface 43d), and in its uncompressed state, it is inclined such that its diameter gradually decreases from the convex ring portion 43f towards the end face 43a (more precisely, the curved surface 43d). The cylindrical portion 43h is located between the convex ring portion 43f and the flange 44, and in its uncompressed state, it has a uniform diameter smaller than that of the convex ring portion 43f. The inclined portion 43i is located between the convex ring portion 43f and the cylindrical portion 43h, and in its uncompressed state, it is inclined such that its diameter gradually decreases from the convex ring portion 43f towards the cylindrical portion 43h.

[0027] When the cylindrical portion 43 is not compressed, the inner circumferential surface 43c of the cylindrical portion 43 has a small diameter portion 43j, a large diameter portion 43k, and an inclined portion 43L. The large diameter portion 43k is located at the axial center of the inner circumferential surface 43c. The small diameter portion 43j is located closer to the end face 43a than the large diameter portion 43k, and when the cylindrical portion 43 is not compressed, it is inclined such that its diameter gradually decreases from the large diameter portion 43k towards the end face 43a (more precisely, the curved surface 43e). Therefore, the small diameter portion 43j can also be called an inclined portion. When the cylindrical portion 43 is not compressed, the large diameter portion 43k has a uniform diameter larger than the diameter of the inclined small diameter portion 43j. The large diameter portion 43k is located closer to the flange 44 than the small diameter portion 43j. When the cylindrical portion 43 is not compressed, at least a portion (most of the portion in the illustrated example) of the large-diameter portion 43k is located closer to the flange 44 than the convex ring portion 43f of the outer peripheral surface 43b.

[0028] The inclined portion 43L of the inner circumferential surface 43c is located closer to the flange 44 than the large diameter portion 43k. When the cylindrical portion 43 is not compressed, the diameter of the inclined portion 43L gradually decreases from the large diameter portion 43k to the inner circumferential surface 44f of the third hole 44e of the flange 44. Small It slopes in that manner.

[0029] The flange 44 is integrally connected to the cylindrical portion 43, positioned outside the first hole 13 of the branch pipe portion 12, and interposed between the first end face 14 of the branch pipe portion 12 and the second end face 21 of the hollow member 20. In other words, the flange 44 faces both the first end face 14 of the branch pipe portion 12 and the second end face 21 of the hollow member 20.

[0030] The flange 44 has an outer protruding ring portion 44a, an inner protruding ring portion 44b, and an end face 44c. The inner protruding ring portion 44b overlaps the outer protruding ring portion 44a radially and is integrally connected to the outer protruding ring portion 44a. The end face 44c is the common end face of the outer protruding ring portion 44a and the inner protruding ring portion 44b.

[0031] The outer protruding ring portion 44a has an outer circumferential surface 44d having an outer diameter larger than the maximum outer diameter of the outer circumferential surface 43b of the cylindrical portion 43. The outer circumferential surface 44d has a uniform outer diameter along the axial direction of the gasket 40, but may be inclined.

[0032] The inner protruding ring portion 44b has a third hole 44e having an inner circumferential surface 44f having an inner diameter smaller than the minimum inner diameter of the inner circumferential surface 43c of the cylindrical portion 43. The inner circumferential surface 44f has a uniform inner diameter along the axial direction of the gasket 40, but may be inclined. The outer circumferential surface 44d of the outer protruding ring portion 44a and the inner circumferential surface 44f of the inner protruding ring portion 44b are concentric with the outer circumferential surface 43b and the inner circumferential surface 43c of the uncompressed cylindrical portion 43.

[0033] The end face 44c extends from the outer protruding ring portion 44a to the inner protruding ring portion 44b. When the flange 44 is not compressed, the end face 44c is a flat surface perpendicular to the axial direction of the gasket 40. The end face 44c is in surface contact with the second end face 21 of the hollow member 20. No protrusions are formed at the corners between the outer circumferential surface 44d and the end face 44c, nor are there any protrusions formed at the corners between the inner circumferential surface 44f and the end face 44c. Because the end face 44c of the flange 44 is flat and no protrusions are formed at these corners, the flange 44 can be easily formed.

[0034] The reinforcing ring 42 is a disc formed from a rigid material, such as metal, and is embedded in the flange 44 of the gasket 40. The reinforcing ring 42 is positioned away from the end face 44c of the flange 44. In this embodiment, the reinforcing ring 42 is exposed on the surface opposite to the end face 44c of the flange 44 (the surface on the cylindrical portion 43 side, the surface on the first end face 14 side of the branch pipe portion 12). The outer circumferential surface of the reinforcing ring 42 is flush with the outer circumferential surface 44d of the flange 44. The inner circumferential surface of the reinforcing ring 42 is concentric with the outer circumferential surface.

[0035] As is clear from the comparison between the uncompressed gasket 40 shown by dashed lines in Figure 3 and the compressed (used) gasket 40 shown by solid lines in Figure 4, the compressed (used) gasket 40, particularly the cylindrical portion 43, is compressed between the stepped portion 13c of the first hole 13 of the branch pipe portion 12 and the raised portion 23 of the second end face 21 of the hollow member 20. Furthermore, the cylindrical portion 43, which is press-fitted into the stepped portion 13c of the first hole 13, is compressed radially inward.

[0036] Therefore, the end face 43a of the cylindrical portion 43 of the gasket 40 is in surface contact with the stepped portion 13c of the first hole 13 of the branch pipe portion 12, and the outer circumferential surface 43b of the cylindrical portion 43 (most of the outer circumferential surface 43b in the illustrated example, but at least the convex ring portion 43f) is in surface contact with the inner circumferential surface of the large diameter hole portion 13b of the first hole 13 of the branch pipe portion 12. The overlap of the cylindrical portion 43 with respect to the branch pipe portion 12 is appropriately set according to the operating environment.

[0037] The end face 44c of the flange 44 of the gasket 40 is flat when it is not in contact with the raised portion 23 of the second end face 21 (when the flange 44 is not compressed). The end face 44c is brought into surface contact with the raised portion 23 of the second end face 21 and is slightly indented by the contact pressure.

[0038] As shown in Figure 4, the second hole 22 of each hollow member 20 communicates with the first hole 13 of the branch pipe section 12 through the third hole 44e of the flange 44 of the gasket 40 corresponding to the hollow member 20 and the internal space of the cylindrical section 43, and further communicates with the hole 11a of the main pipe section 11.

[0039] In this embodiment, the cylindrical portion 43 of the elastic portion 41 of the gasket 40, which is made of rubber, is press-fitted into the first hole 13 of the branch pipe portion 12, so that at least the convex ring portion 43f of the outer peripheral surface 43b of the cylindrical portion 43 makes surface contact with the inner peripheral surface of the large diameter hole portion 13b of the first hole 13. The flange 44 of the elastic portion 41 of the gasket 40 is interposed between the first end face 14 of the branch pipe portion 12 and the hollow member 20, so that the end face 44c of the flange 44 makes surface contact with the raised portion 23 of the hollow member 20. The flange 44 has an outer protruding ring portion 44a and an inner protruding ring portion 44b. The outer protruding ring portion 44a has an outer diameter larger than the maximum outer diameter of the outer circumferential surface 43b of the cylindrical portion 43, and the inner protruding ring portion 44b has an inner diameter smaller than the minimum inner diameter of the inner circumferential surface 43c of the cylindrical portion 43. The end face 44c of the flange 44 extends from the outer protruding ring portion 44a to the inner protruding ring portion 44b. Because the flange 44 has a large end face 44c, it makes reliable surface contact with the hollow member 20. Therefore, even if the second hole 22 of the hollow member 20 is eccentric with respect to the first hole 13 of the branch pipe portion 12, the gasket 40 can reliably seal the branch pipe portion 12 and the hollow member 20.

[0040] In particular, in this embodiment, since the diameter of the second hole 22 of the hollow member 20 is larger than the diameter of the small-diameter hole portion 13a of the first hole 13 of the branch pipe portion 12, the area in which the gasket contacts the second end face 21 of the hollow member 20 is limited.

[0041] However, in this embodiment, as described above, the flange 44 has a large end face 44c that extends from the outer protruding ring portion 44a to the inner protruding ring portion 44b, and the end face 44c of the flange 44 makes reliable surface contact with the second end face 21 of the hollow member 20. Therefore, even if the second hole 22 of the hollow member 20 is eccentric with respect to the first hole 13 of the branch pipe portion 12, the gasket 40 can reliably seal the branch pipe portion 12 and the hollow member 20.

[0042] In the gasket 40, at least a portion of the large-diameter portion 43k of the inner circumferential surface 43c of the cylindrical portion 43 is located closer to the flange 44 than the convex ring portion 43f of the outer circumferential surface 43b of the cylindrical portion 43. Therefore, when the cylindrical portion 43 is press-fitted into the first hole 13 of the branch pipe portion 12, the cylindrical portion 43 is prone to elastic deformation radially inward. Consequently, even if the first hole 13 of the branch pipe portion 12 has a shape that compresses the gasket 40 in its axial direction, the cylindrical portion 43 is prone to making gap-free surface contact with the inner circumferential surface of the large-diameter hole portion 13b of the first hole 13.

[0043] In the gasket 40, the inner circumferential surface 43c of the cylindrical portion 43 gradually increases in diameter from the large diameter portion 43k to the inner circumferential surface 44f of the inner protruding ring portion 44b of the flange 44. Small It has an inclined portion 43L that slopes in such a way. As a result, there are no areas where there is a sudden dimensional change and excessive stress is concentrated on the inner circumferential surface 43c of the cylindrical portion 43 and the inner circumferential surface 44f of the flange 44, and the life of the gasket 40 can be extended. In addition, since the inner protruding ring portion 44b of the flange 44 is reinforced by the inclined portion 43L of the cylindrical portion 43, even if the cylindrical portion 43 that is press-fitted into the first hole 13 of the branch pipe portion 12 deforms, the shape of the flange 44 is maintained and the end face 44c of the flange 44 makes reliable surface contact with the raised portion 23 of the second end face 21 of the hollow member 20.

[0044] As described above, the multiple branch pipe sections 12 do not move relative to each other, but the spacing between the second holes 22 of the multiple hollow members 20 can change, so the second hole 22 of the hollow member 20 corresponding to a particular branch pipe section 12 can be eccentric with respect to the first hole 13 of that branch pipe section 12. In Figure 1, the two first holes 13 are concentric with the two second holes 22, respectively, but in Figures 3 and 4, the right-side first hole 13 is eccentric with respect to the right-side second hole 22, and the right-side gasket 40 fitted into the right-side first hole 13 is offset to the right with respect to the right-side second hole 22.

[0045] However, since the gasket 40 has a flange 44 with a large surface area, and the end face 44c of the flange 44 makes surface contact with the raised portion 23 of the second end face 21 of the hollow member 20, the gasket 40 can reliably seal the branch pipe section 12 and the hollow member 20 even if the second hole 22 of the hollow member 20 is eccentric with respect to the first hole 13 of the branch pipe section 12.

[0046] According to this embodiment, an annular raised portion 23 is formed on the second end face 21 of the hollow member 20, surrounding the second hole 22 around its entire circumference, thus limiting the area in which the gasket 40 contacts the second end face 21 of the hollow member 20. However, because the end face 44c of the flange 44 of the gasket 40 is flat, even if the second hole 22 of the hollow member 20 is eccentric with respect to the first hole 13 of the branch pipe portion 12, the flat end face 44c of the flange 44 makes surface contact with the raised portion 23 of the hollow member 20, allowing the gasket 40 to reliably seal the branch pipe portion 12 and the hollow member 20.

[0047] According to this embodiment, a rigid disc reinforcing ring 42 is embedded in the flange 44 of the gasket 40 at a position away from the end face 44c of the flange 44. Therefore, the reinforcing ring 42 can reinforce the flange 44, and the reinforcing ring 42 does not prevent the flexible end face 44c of the flange 44 from making surface contact with the raised portion 23 of the hollow member 20. Furthermore, since the reinforcing ring 42 is positioned away from the end face 44c of the flange 44 that contacts the hollow member 20, even if the flange 44 collides with the first end face 14 of the branch pipe portion 12 when the cylindrical portion 43 is press-fitted into the large-diameter hole 13b of the branch pipe portion 12, the reinforcing ring 42 can minimize damage to the end face 44c of the flange 44.

[0048] The reinforcing ring 42 is a flat plate and is positioned perpendicular to the central axis of the first hole 13 and the central axis of the second hole 22. The reinforcing ring 42 does not have any protruding portions in the thickness direction of the reinforcing ring 42 (the direction parallel to the axial direction of the gasket 40, i.e., the axis of the first hole 13 and the axis of the second hole 22). Therefore, it is not necessary to make the flange 44 thicker, and the gap between the first end face 14 of the branch pipe section 12 and the second end face 21 of the hollow member 20 may be small.

[0049] Second Embodiment A sealing structure according to a second embodiment of the present invention will be described with reference to Figures 5 and 6. In the drawings from Figure 5 onward, the same reference numerals are used to indicate components that have already been described, and these components will not be described in detail.

[0050] As shown in Figure 5, the gasket 50 used in the sealing structure according to the second embodiment is similar to the gasket 40 used in the sealing structure according to the first embodiment, but an annular raised portion 55 is formed on the end face 54c of the flange 44 that surface-contacts the hollow member 20, surrounding the third hole 44e of the gasket 50 around its entire circumference. The raised portion 55 is concentric with the outer circumferential surface 44d of the flange 44 and the inner circumferential surface 44f of the third hole 44e, and is formed at a position away from the third hole 44e.

[0051] The raised portion 55 of the flange 44 has a cross-sectional shape that is part of an ellipse when not compressed. The ellipse may be a circle. However, the shape of the raised portion 55 is not limited to a shape that is part of an ellipse. The width W of the raised portion 55 (half the difference between the outer diameter D1 and the inner diameter D2) is smaller than half the width of the end face 54c (half the difference between the diameter of the outer circumferential surface 44d of the flange 44 and the diameter of the inner circumferential surface 44f).

[0052] As shown in Figure 6, the second end face 21 of the hollow member 20 has a flat surface. The raised portion 55 of the end face 54c of the flange 44 is in surface contact with the flat surface of the second end face 21. In the illustrated embodiment, the entire second end face 21 is flat, but a part of the second end face 21 may have an annular flat surface, and the raised portion 55 may be in surface contact with that flat surface.

[0053] The width W2 of the flat surface of the second end face 21 of the hollow member 20 is greater than the width W of the raised portion 55 of the flange 44. Also, the diameter of the second hole 22 of the hollow member 20 is smaller than the inner diameter D2 of the raised portion 55.

[0054] According to this embodiment, a raised portion 55 is formed on the end face 54c of the flange 44 of the gasket 50, which is compressed to enhance sealing performance. Since the raised portion 55 of the flange 44 makes surface contact with the flat surface of the second end face 21 of the hollow member 20, the gasket 50 can reliably seal the branch pipe portion 12 and the hollow member 20 even if the second hole 22 of the hollow member 20 is eccentric with respect to the first hole 13 of the branch pipe portion 12.

[0055] As described above, the multiple branch pipe sections 12 do not move relative to each other, but the spacing between the second holes 22 of the multiple hollow members 20 can change, so the second hole 22 of the hollow member 20 corresponding to a particular branch pipe section 12 can be eccentric with respect to the first hole 13 of that branch pipe section 12. In Figure 6, the right-side first hole 13 is eccentric with respect to the right-side second hole 22, and the right-side gasket 50 fitted into the right-side first hole 13 is biased to the right with respect to the right-side second hole 22.

[0056] However, the gasket 50 has a flange 44 with a large surface area, and the inner diameter D2 of the raised portion 55 on the end face 54c of the flange 44 is larger than the diameter of the second hole 22 of the hollow member 20, and the width W of the raised portion 55 is smaller than the width W2 of the flat surface of the second end face 21 of the hollow member 20. Therefore, the raised portion 55 makes surface contact with the flat surface of the second end face 21 of the hollow member 20, so even if the second hole 22 of the hollow member 20 is eccentric with respect to the first hole 13 of the branch pipe portion 12, the gasket 50 can reliably seal the branch pipe portion 12 and the hollow member 20.

[0057] Furthermore, when the gasket 50 is placed between the branch pipe section 12 and the hollow member 20, the cylindrical section 43 is press-fitted into the first hole 13 of the branch pipe section 12 and restrained, and the gasket 50 is compressed between the stepped section 13c of the first hole 13 and the second end face 21 of the hollow member 20. In order to prevent unnecessary stress from being generated inside the elastic portion 41 of the gasket 50 after placement, it is preferable that the flange 44 be in a concentric position with respect to the cylindrical section 43. As shown in the figure, the raised portion 55 has a cross-sectional shape that is part of an ellipse when not compressed, so the contact area between the raised portion 55 of the flange 44 and the hollow member 20 is small. Therefore, when the force compressing the gasket 50 in the axial direction is small, the flange 44 can move with a small force relative to the hollow member 20 when the flange 44 returns to a concentric position with respect to the cylindrical section 43. Thus, the flange 44 can return to a concentric position with respect to the cylindrical section 43 without being subjected to a large shear force on the elastic portion 41 of the gasket 50.

[0058] Third Embodiment A sealing structure according to a third embodiment of the present invention will be described with reference to Figures 7 and 8.

[0059] As shown in Figure 7, the gasket 60 used in the sealing structure according to the third embodiment is similar to the gasket 50 used in the sealing structure according to the second embodiment, but the end face 64c of the flange 44 that surface-contacts the hollow member 20 has two annular protrusions 65, 66 that surround the third hole 44e of the gasket 60 all around. The protrusions 65, 66 are concentric with the outer circumferential surface 44d of the flange 44 and the third hole 44e. The inner protrusion 65 is formed at a position away from the third hole 44e of the flange 44.

[0060] Each of the raised portions 65 and 66 of the flange 44 has a cross-sectional shape that is part of an ellipse when not compressed. The ellipse may be a circle. However, the shape of the raised portions 65 and 66 is not limited to being part of an ellipse. Half the difference W1 between the outer diameter D3 of the outer raised portion 66 and the inner diameter D4 of the inner raised portion 66 is smaller than the width of the end face 64c (half the difference between the diameter of the outer circumferential surface 44d of the flange 44 and the diameter of the inner circumferential surface 44f).

[0061] As shown in Figure 8, the second end face 21 of the hollow member 20 has a flat surface. The raised portions 65 and 66 of the end face 64c of the flange 44 are in surface contact with the flat surface of the second end face 21. In the illustrated embodiment, the entire second end face 21 is flat, but a part of the second end face 21 may have an annular flat surface, and the raised portions 65 and 66 may be in surface contact with that flat surface.

[0062] The width W2 of the flat surface of the second end face 21 of the hollow member 20 is greater than half W1, which is the difference between the outer diameter D3 of the outer protrusion 66 and the inner diameter D4 of the inner protrusion 66. Also, the diameter of the second hole 22 of the hollow member 20 is smaller than the inner diameter D4 of the protrusion 65.

[0063] According to this embodiment, raised portions 65 and 66 are formed on the end face 64c of the flange 44 of the gasket 60, which are compressed to enhance sealing performance. Since the raised portions 65 and 66 of the flange 44 make surface contact with the flat surface of the second end face 21 of the hollow member 20, the gasket 60 can reliably seal the branch pipe portion 12 and the hollow member 20 even if the second hole 22 of the hollow member 20 is eccentric with respect to the first hole 13 of the branch pipe portion 12.

[0064] As described above, the multiple branch pipe sections 12 do not move relative to each other, but the spacing between the second holes 22 of the multiple hollow members 20 can change, so the second hole 22 of the hollow member 20 corresponding to a particular branch pipe section 12 can be eccentric with respect to the first hole 13 of that branch pipe section 12. In Figure 8, the right-side first hole 13 is eccentric with respect to the right-side second hole 22, and the right-side gasket 60 fitted into the right-side first hole 13 is biased to the right with respect to the right-side second hole 22.

[0065] However, the gasket 60 has a flange 44 with a large surface area, and the inner diameter D4 of the raised portion 65 on the end face 64c of the flange 44 is larger than the diameter of the second hole 22 of the hollow member 20, and half the difference W1 between the outer diameter D3 of the outer raised portion 66 and the inner diameter D4 of the inner raised portion 66 is smaller than the width W2 of the flat surface of the second end face 21 of the hollow member 20. Therefore, the raised portions 65 and 66 on the end face 64c of the flange 64 make surface contact with the flat surface of the second end face 21 of the hollow member 20, so even if the second hole 22 of the hollow member 20 is eccentric with respect to the first hole 13 of the branch pipe portion 12, the gasket 60 can reliably seal the branch pipe portion 12 and the hollow member 20. Even if the eccentricity of the second hole 22 relative to the first hole 13 is large, and a part of the radially inward raised portion 65 separates from the second end face 21, the radially outward raised portion 66 will still make surface contact with the flat surface of the second end face 21, so the gasket 60 can reliably seal the branch pipe portion 12 and the hollow member 20.

[0066] Furthermore, when the gasket 60 is placed between the branch pipe section 12 and the hollow member 20, the cylindrical section 43 is press-fitted into the first hole 13 of the branch pipe section 12 and restrained, and the gasket 60 is compressed between the stepped section 13c of the first hole 13 and the second end face 21 of the hollow member 20. In order to prevent unnecessary stress from being generated inside the elastic portion 41 of the gasket 60 after placement, it is preferable that the flange 44 be in a concentric position with respect to the cylindrical section 43. As shown in the figure, each of the raised sections 65 and 66 has a cross-sectional shape that is part of an ellipse when not compressed, so the contact area between the raised sections 65 and 66 of the flange 44 and the hollow member 20 is small. For this reason, when the force compressing the gasket 60 in the axial direction is small, the flange 44 can move with a small force relative to the hollow member 20 when the flange 44 returns to a concentric position with respect to the cylindrical section 43. Therefore, the flange 44 can be restored to a concentric position with respect to the cylindrical portion 43 without a large shear force being applied to the elastic portion 41 of the gasket 60.

[0067] Variation Although the present invention has been illustrated and described above with reference to preferred embodiments, those skilled in the art will understand that modifications to form and detail are possible without departing from the scope of the invention as described in the claims. Such modifications, alterations, and changes should be included within the scope of the present invention.

[0068] Figures 9 to 13 show modified examples of the gasket 40 according to the first embodiment.

[0069] In the modified example shown in Figure 9, the outer protruding ring portion 44a of the flange 44 of the elastic portion 41 has a projection 44g that protrudes radially outward from the reinforcing ring 42. The projection 44g may be annular, formed around the entire circumference of the flange 44. Alternatively, multiple projections 44g may be formed around the flange 44 at angular intervals.

[0070] In the modified example shown in Figure 10, the flange 44 of the elastic portion 41 not only covers the surface of the reinforcing ring 42 on the hollow member 20 side, but also covers the surface of the reinforcing ring 42 on the branch pipe portion 12 side (the surface on the cylindrical portion 43 side). That is, the flange 44 has a cover layer 44h that covers the entire surface of the reinforcing ring 42 on the branch pipe portion 12 side. The cover layer 44h is annular and formed around the entire circumference of the flange 44.

[0071] Therefore, the reinforcing ring 42 is not exposed on the first end face 14 side (the cylindrical portion 43 side) of the branch pipe portion 12 in the flange 44. Since the reinforcing ring 42 is not exposed on the end face 44c on the second end face 21 side of the hollow member 20 in the flange 44, and is not exposed on the first end face 14 side of the branch pipe portion 12 in the flange 44, the reinforcing ring 42 is protected from air and is less prone to rusting. Therefore, the reinforcing ring 42 can be formed from an inexpensive metal with poor corrosion resistance, such as iron.

[0072] In the modified example shown in Figure 11, the flange 44 of the elastic portion 41 has a projection 44g that protrudes radially outward from the reinforcing ring 42, and a cover layer 44h that covers the entire surface of the reinforcing ring 42 on the side of the branch pipe portion 12. That is, the modified example in Figure 11 is a combination of the modified examples in Figure 9 and Figure 10. The reinforcing ring 42 is hardly exposed on the surface of the flange 44 on the side of the first end face 14 of the branch pipe portion 12. Since the reinforcing ring 42 is not exposed on the end face 44c on the side of the second end face 21 of the hollow member in the flange 44, and is hardly exposed on the surface of the flange 44 on the side of the first end face 14 of the branch pipe portion 12, the reinforcing ring 42 is protected from air and is less prone to rusting. Therefore, the reinforcing ring 42 can be formed from an inexpensive metal with poor corrosion resistance, such as iron.

[0073] In the modified example shown in Figure 12, the flange 44 of the elastic portion 41 completely surrounds the reinforcing ring 42. In other words, the reinforcing ring 42 is completely embedded in the flange 44. The reinforcing ring 42 is protected from air by the flange 44 and is therefore resistant to rust. Thus, the reinforcing ring 42 can be formed from an inexpensive metal with poor corrosion resistance, such as iron.

[0074] In the modified example shown in Figure 13, the reinforcing ring 42 has a protruding portion 42a at its inner edge that protrudes in the thickness direction of the reinforcing ring 42 (the axial direction of the gasket 40). The protruding portion 42a is completely embedded in the cylindrical portion 43 and reinforces the cylindrical portion 43. In the modified examples shown in Figures 9 to 11, the reinforcing ring 42 may also be provided with a protruding portion 42a.

[0075] Although not shown, the gasket 50 according to the second embodiment and the gasket 60 according to the third embodiment may also be modified according to the modifications shown in Figures 9 to 13.

[0076] Aspects of the present invention are also described in the numbered clauses below.

[0077] Clause 1. A gasket interposed between a tubular portion having a first hole and a hollow member having a second hole, and compressed between the end face of the tubular portion and the hollow member, The gasket has an elastic portion formed from rubber, The aforementioned elastic portion The cylindrical portion is press-fitted into the first hole of the tubular portion, and has an outer circumferential surface and an inner circumferential surface, the outer circumferential surface having a convex ring portion projecting radially outward at its axial center, and at least the convex ring portion making surface contact with the inner circumferential surface of the first hole, A flange integrally connected to the cylindrical portion, concentrically positioned with the cylindrical portion, and interposed between the end face of the pipe portion and the hollow member, comprising: an outer protruding ring portion having an outer circumferential surface having an outer diameter larger than the maximum outer diameter of the outer circumferential surface of the cylindrical portion; an inner protruding ring portion having an inner circumferential surface having an inner diameter smaller than the minimum inner diameter of the inner circumferential surface of the cylindrical portion; and an end face having a portion that makes surface contact with the hollow member, wherein the inner protruding ring portion overlaps the outer protruding ring portion radially, and the end face extends from the outer protruding ring portion to the inner protruding ring portion. gasket.

[0078] Clause 2. When the cylindrical portion is not compressed, the inner circumferential surface of the cylindrical portion of the elastic portion has a small diameter portion and a large diameter portion having a larger diameter than the diameter of the small diameter portion and located closer to the flange than the small diameter portion. When the cylindrical portion is not compressed, at least a part of the large-diameter portion is located closer to the flange than the convex ring portion on the outer circumferential surface of the cylindrical portion. The gasket described in Clause 1, characterized by the features described herein.

[0079] According to this clause, since at least a portion of the large-diameter portion on the inner circumferential surface of the cylindrical portion is located closer to the flange than the convex ring portion on the outer circumferential surface of the cylindrical portion, when the cylindrical portion is press-fitted into the first hole of the pipe portion, the cylindrical portion is more likely to elastically deform radially inward. Therefore, even if the first hole of the pipe portion has a shape that compresses the gasket in its axial direction, the cylindrical portion is more likely to make gap-free surface contact with the inner circumferential surface of the first hole.

[0080] Clause 3. When the cylindrical portion is not compressed, the inner circumferential surface of the cylindrical portion of the elastic portion has a gradually increasing diameter from the large diameter portion to the inner circumferential surface of the inner protruding ring portion of the flange. Small It further has an inclined section that slopes in such a way. The gasket described in Clause 2, characterized by the features described herein.

[0081] According to this clause, having such an inclined portion on the inner surface of the cylindrical part prevents areas where there is abrupt dimensional changes and excessive stress concentration between the inner surface of the cylindrical part and the inner surface of the flange, thereby extending the life of the gasket. Furthermore, since the inner protruding ring portion of the flange is reinforced by the inclined portion of the cylindrical part, even if the cylindrical part pressed into the first hole of the pipe portion deforms, the shape of the flange is maintained, and at least a portion of the end face of the flange reliably makes surface contact with the hollow member.

[0082] Clause 4. The elastic portion further comprises a reinforcing ring made of a rigid material embedded in the flange, wherein the reinforcing ring is positioned away from the end face of the flange. A gasket as described in any one of clauses 1 to 3, characterized by the features described herein.

[0083] According to this clause, a reinforcing ring, which is a rigid disc, is embedded at a position away from the end face of the flange. Therefore, the reinforcing ring can reinforce the flange, and it does not prevent at least a portion of the flexible flange end face from making surface contact with the hollow member. Furthermore, because the reinforcing ring is positioned away from the flange end face that contacts the hollow member, even if the flange collides with the end face of the pipe when the cylindrical part is press-fitted into the large-diameter part of the pipe, the reinforcing ring can minimize damage to the flange end face.

[0084] Clause 5. The flange of the elastic portion has a cover layer that covers the entire surface of the cylindrical portion side of the reinforcing ring. The gasket described in Clause 4, characterized by the features described herein.

[0085] According to this clause, the reinforcing ring is not exposed on the end face of the flange on the hollow member side, nor on the pipe-side face of the flange, so the reinforcing ring is protected from air and less prone to rusting. Therefore, the reinforcing ring can be formed from an inexpensive metal with poor corrosion resistance, such as iron.

[0086] Clause 6. The reinforcing ring is a flat plate and does not have any portion that protrudes in the axial direction of the gasket. A gasket as described in clause 4 or 5, characterized by the features described herein.

[0087] According to this clause, there is no need to thicken the flange, and therefore the gap between the end face of the pipe section and the hollow member may be small.

[0088] Clause 7. When the flange is not compressed, the end face of the flange is flat. A gasket as described in any one of clauses 1 to 6, characterized by the features described herein.

[0089] According to this clause, the flange can be easily formed. Furthermore, even if an annular ridge is formed on the end face of the hollow member to which the flange contacts, limiting the area in which the gasket contacts the end face of the hollow member, the end face of the flange of the gasket is flat, so the flat end face of the flange makes surface contact with the ridge of the hollow member, and the gasket can reliably seal the pipe and the hollow member.

[0090] Clause 8. The end face of the flange has at least one annular protrusion that surrounds the inner circumferential surface of the inner protruding ring around its entire circumference, and the protrusion is in surface contact with the hollow member. A gasket as described in any one of clauses 1 to 6, characterized by the features described herein.

[0091] According to this clause, a raised portion is formed on the end face of the flange to enhance sealing performance when compressed. Since the raised portion of the flange makes surface contact with the hollow member, the gasket can reliably seal the pipe and the hollow member even if the second hole of the hollow member is eccentric with respect to the first hole of the pipe.

[0092] Clause 9. The raised portion of the flange has a cross-sectional shape that is part of an ellipse when not compressed. The gasket described in Clause 8, characterized by the features described herein.

[0093] When the gasket is placed between the pipe and the hollow member, the cylindrical portion is pressed into the first hole of the pipe and restrained, and the gasket is compressed between the pipe and the hollow member. To prevent unnecessary stress from being generated inside the elastic portion of the gasket after placement, it is preferable that the flange be concentric with respect to the cylindrical portion. According to this clause, since the raised portion has a cross-sectional shape that is part of an ellipse when not compressed, the contact area between the raised portion of the flange and the hollow member is small. Therefore, when the force compressing the gasket in the axial direction is small, the flange can move with a small force relative to the hollow member when the flange returns to a concentric position relative to the cylindrical portion. Consequently, the flange can return to a concentric position relative to the cylindrical portion without applying a large shear force to the elastic portion of the gasket.

[0094] Clause 10. The tubular portion having a first end face and the first hole, The hollow member having a second end face opposite to the first end face of the pipe portion and the second hole, Having a gasket as described in any one of clauses 1 to 6, The flange of the gasket is interposed between the first end face of the pipe portion and the second end face of the hollow member, and the end face of the flange has a portion that is in surface contact with the second end face of the hollow member. Sealed structure.

[0095] Clause 11. The first hole in the pipe portion has a small diameter hole portion, a large diameter hole portion having a larger diameter than the small diameter hole portion and positioned closer to the first end face than the small diameter hole portion, and a stepped portion connecting the small diameter hole portion and the large diameter hole portion. The second hole of the hollow member communicates with the first hole of the tubular portion and has a diameter smaller than the diameter of the large-diameter hole portion of the first hole but larger than the diameter of the small-diameter hole portion. The cylindrical portion of the gasket is press-fitted into the large-diameter hole of the first hole. The cylindrical portion of the gasket further has an end face that makes surface contact with the stepped portion of the first hole. The sealing structure according to clause 10, characterized by the following:

[0096] According to this clause, the diameter of the second hole in the hollow member is larger than the diameter of the small-diameter first hole in the pipe section, thus limiting the area in which the gasket contacts the second end face of the hollow member. However, as described above, the flange has a large end face that extends from the outer protruding ring to the inner protruding ring, and the end face of the flange makes reliable surface contact with the hollow member. Therefore, even if the second hole in the hollow member is eccentric with respect to the first hole in the branch pipe section, the gasket can reliably seal the branch pipe section and the hollow member.

[0097] Clause 12. The second end face of the hollow member is formed with an annular protrusion that surrounds the second hole around its entire circumference. When the flange is not compressed, the end face of the flange of the gasket is flat and in surface contact with the raised portion of the second end face. The sealing structure according to clause 11, characterized by the following:

[0098] According to this clause, the flange can be easily formed because the end face of the flange is flat. An annular protrusion is formed on the second end face of the hollow member, which limits the area in which the gasket contacts the second end face of the hollow member. However, because the end face of the flange of the gasket is flat, even if the second hole of the hollow member is eccentric with respect to the first hole of the pipe, the flat end face of the flange makes surface contact with the protrusion of the hollow member, and the gasket can reliably seal the pipe and the hollow member.

[0099] Clause 13. The second end face of the hollow member has a flat surface. The end face of the flange of the gasket has at least one annular protrusion that surrounds the inner circumferential surface of the inner protruding ring portion around its entire circumference, and the protrusion is in surface contact with the flat surface of the second end face. The sealing structure according to clause 11, characterized by the following:

[0100] According to this clause, a raised portion is formed on the end face of the flange of the gasket, which is compressed to enhance sealing performance. Since the raised portion of the flange makes surface contact with the flat surface of the second end face of the hollow member, the gasket can reliably seal the pipe and the hollow member even if the second hole of the hollow member is eccentric with respect to the first hole of the pipe.

[0101] Clause 14. The raised portion of the flange has a cross-sectional shape that is part of an ellipse when the flange is not compressed. The sealing structure according to clause 13, characterized by the following:

[0102] When the gasket is placed between the pipe and the hollow member, the cylindrical portion is pressed into the first hole of the pipe and restrained, and the gasket is compressed between the pipe and the hollow member. To prevent unnecessary stress from being generated inside the elastic portion of the gasket after placement, it is preferable that the flange be concentric with respect to the cylindrical portion. According to this clause, since the raised portion has a cross-sectional shape that is part of an ellipse when not compressed, the contact area between the raised portion of the flange and the hollow member is small. Therefore, when the force compressing the gasket in the axial direction is small, the flange can move with a small force relative to the hollow member when the flange returns to a concentric position relative to the cylindrical portion. Consequently, the flange can return to a concentric position relative to the cylindrical portion without applying a large shear force to the elastic portion of the gasket.

[0103] Clause 15. A plurality of the aforementioned pipe sections, which are arranged parallel to each other at intervals and are not movable relative to each other, A plurality of the hollow members arranged such that the distance between the central axes of the second holes can be changed, Each gasket comprises a plurality of gaskets that seal the space between one of the pipe sections and one of the hollow members. A sealing structure according to any one of clauses 10 to 14, characterized by the features described herein.

[0104] According to this clause, although the multiple pipe sections do not move relative to each other, the spacing between the second holes of the multiple hollow members may change, so that the second hole of the hollow member corresponding to a pipe section may be eccentric with respect to the first hole of that pipe section. However, since the gasket has a flange with a large surface area, and at least a portion of the end face of the flange is in surface contact with the second end face of the hollow member, the gasket can reliably seal the pipe section and the hollow member even if the second hole of the hollow member is eccentric with respect to the first hole of the pipe section.

[0105] Clause 16. Further comprising at least one intervening member interposed between a plurality of the hollow members. The sealing structure according to clause 15, characterized by the following:

[0106] According to this clause, because intervening members are interposed between hollow members, the spacing between the second holes of multiple hollow members is unstable due to the dimensional accuracy and / or deformation of the intervening members. Therefore, the second hole of a hollow member corresponding to a pipe section may be eccentric with respect to the first hole of a pipe section. However, since the gasket has a flange with a large surface area, and at least a portion of the end face of the flange is in surface contact with the second end face of the hollow member, the gasket can reliably seal the pipe section and the hollow member even if the second hole of the hollow member is eccentric with respect to the first hole of the pipe section.

[0107] Clause 17. The intervening member has less rigidity than the hollow member. The sealing structure according to clause 16, characterized by the following:

[0108] According to this clause, because the hollow members have low rigidity, the spacing between the second holes of multiple hollow members is unstable due to the deformation of the intervening members. Therefore, the second hole of the hollow member corresponding to a pipe section may be eccentric with respect to the first hole of a pipe section. However, since the gasket has a flange with a large surface area, and at least a portion of the end face of the flange is in surface contact with the second end face of the hollow member, the gasket can reliably seal the pipe section and the hollow member even if the second hole of the hollow member is eccentric with respect to the first hole of the pipe section. [Explanation of Symbols]

[0109] 12 Branch pipe section (pipe section) 13 First hole 13a Small diameter hole 13b Large diameter hole 13c Step section 14 First end face 20 Hollow member 21 Second end face 22 Second hole 23 Ridge 30 Intervening member 40 Gasket 41 Elastic part 42 Reinforcement ring 43 Cylindrical section 43a End face 43b Outer surface 43c Inner surface 43d curved surface 43j Small diameter section 43k Large diameter section 43L Slope section 44 Flange 44a Outer protruding ring 44b Inner protruding ring 44c end face 44d Outer surface 44e Third hole 44f Inner surface 50 Gaskets 54c end face 55 Ridge 60 Gasket 64c end face 65,66 Ridge

Claims

1. A gasket interposed between a tubular portion having a first hole and a hollow member having a second hole, and compressed between the end face of the tubular portion and the hollow member, The gasket has an elastic portion formed from rubber, The aforementioned elastic portion The cylindrical portion is press-fitted into the first hole of the tubular portion, and has an outer circumferential surface and an inner circumferential surface, the outer circumferential surface having a convex ring portion projecting radially outward at its axial center, and at least the convex ring portion making surface contact with the inner circumferential surface of the first hole, A flange integrally connected to the cylindrical portion, concentrically positioned with the cylindrical portion, and interposed between the end face of the pipe portion and the hollow member, comprising: an outer protruding ring portion having an outer circumferential surface having an outer diameter larger than the maximum outer diameter of the outer circumferential surface of the cylindrical portion; an inner protruding ring portion having an inner circumferential surface having an inner diameter smaller than the minimum inner diameter of the inner circumferential surface of the cylindrical portion; and an end face having a portion that makes surface contact with the hollow member, wherein the inner protruding ring portion overlaps the outer protruding ring portion radially, and the end face extends from the outer protruding ring portion to the inner protruding ring portion; When the cylindrical portion is not compressed, the inner circumferential surface of the cylindrical portion of the elastic portion has a small diameter portion and a large diameter portion that has a larger diameter than the diameter of the small diameter portion and is located closer to the flange than the small diameter portion. When the cylindrical portion is not compressed, at least a part of the large-diameter portion is located closer to the flange than the convex ring portion on the outer circumferential surface of the cylindrical portion. gasket.

2. A gasket interposed between a tubular portion having a first hole and a hollow member having a second hole, and compressed between the end face of the tubular portion and the hollow member, The gasket has an elastic portion formed from rubber, The aforementioned elastic portion The cylindrical portion is press-fitted into the first hole of the tubular portion, and has an outer circumferential surface and an inner circumferential surface, the outer circumferential surface having a convex ring portion projecting radially outward at its axial center, and at least the convex ring portion making surface contact with the inner circumferential surface of the first hole, A flange integrally connected to the cylindrical portion, concentrically positioned with the cylindrical portion, interposed between the end face of the pipe portion and the hollow member, and compressed between the end face of the pipe portion and the hollow member, comprising: an outer protruding ring portion having an outer circumferential surface having an outer diameter larger than the maximum outer diameter of the outer circumferential surface of the cylindrical portion; an inner protruding ring portion having an inner circumferential surface having an inner diameter smaller than the minimum inner diameter of the inner circumferential surface of the cylindrical portion; and an end face having a portion that makes surface contact with the hollow member, wherein the inner protruding ring portion overlaps the outer protruding ring portion radially, and the end face extends from the outer protruding ring portion to the inner protruding ring portion. The flange is positioned outside the first hole, When the flange is not compressed, the end face of the flange is flat. gasket.

3. When the cylindrical portion is not compressed, the inner circumferential surface of the cylindrical portion of the elastic portion further has an inclined portion that slopes such that the diameter gradually decreases from the large diameter portion to the inner circumferential surface of the inner protruding ring portion of the flange. The gasket according to feature 1.

4. The elastic portion further comprises a reinforcing ring made of a rigid material embedded in the flange, wherein the reinforcing ring is positioned away from the end face of the flange. The gasket according to any one of claims 1 to 3.

5. The flange of the elastic portion has a cover layer that covers the entire surface of the cylindrical portion side of the reinforcing ring. The gasket according to feature 4.

6. The reinforcing ring is a flat plate and does not have any portion that protrudes in the axial direction of the gasket. The gasket according to claim 4 or 5.

7. When the flange is not compressed, the end face of the flange is flat. The gasket according to feature 1 or 3.

8. The end face of the flange has at least one annular protrusion that surrounds the inner circumferential surface of the inner protruding ring portion around its entire circumference, and the protrusion is in surface contact with the hollow member. The gasket according to feature 1 or 3.

9. The raised portion of the flange has a cross-sectional shape that is part of an ellipse when it is not compressed. The gasket according to feature 8.

10. The tubular portion having a first end face and the first hole, The hollow member having a second end face opposite to the first end face of the pipe portion and the second hole, The gasket is as described in any one of claims 1 to 9, The flange of the gasket is interposed between the first end face of the pipe portion and the second end face of the hollow member, and the end face of the flange has a portion that is in surface contact with the second end face of the hollow member. Sealed structure.

11. The first hole in the pipe portion has a small diameter hole portion, a large diameter hole portion having a larger diameter than the small diameter hole portion and positioned closer to the first end face than the small diameter hole portion, and a stepped portion connecting the small diameter hole portion and the large diameter hole portion. The second hole of the hollow member communicates with the first hole of the tubular portion and has a diameter smaller than the diameter of the large-diameter hole portion of the first hole but larger than the diameter of the small-diameter hole portion. The cylindrical portion of the gasket is press-fitted into the large-diameter hole of the first hole. The cylindrical portion of the gasket further has an end face that makes surface contact with the stepped portion of the first hole. The sealing structure according to claim 10.

12. A tubular portion having a first end face and a first hole opening at the first end face, A hollow member having a second end face opposite to the first end face of the pipe portion, and a second hole opening at the second end face, The gasket is interposed between the pipe portion and the hollow member and is compressed between the pipe portion and the second end face of the hollow member, The second end face of the hollow member has an annular protrusion that surrounds the second hole around its entire circumference. The gasket has an elastic portion formed from rubber, The aforementioned elastic portion The cylindrical portion is press-fitted into the first hole of the tubular portion, and has an outer circumferential surface and an inner circumferential surface, the outer circumferential surface having a convex ring portion projecting radially outward at its axial center, and at least the convex ring portion making surface contact with the inner circumferential surface of the first hole, A flange integrally connected to the cylindrical portion, concentrically positioned with the cylindrical portion, interposed between the first end face of the tubular portion and the second end face of the hollow member, and compressed between the first end face of the tubular portion and the second end face of the hollow member, comprising: an outer protruding ring portion having an outer circumferential surface having an outer diameter larger than the maximum outer diameter of the outer circumferential surface of the cylindrical portion; an inner protruding ring portion having an inner circumferential surface having an inner diameter smaller than the minimum inner diameter of the inner circumferential surface of the cylindrical portion; and an end face having a portion that makes surface contact with the hollow member, wherein the inner protruding ring portion overlaps the outer protruding ring portion radially, and the end face extends from the outer protruding ring portion to the inner protruding ring portion. The flange is positioned outside the first hole, When the flange is not compressed, the end face of the flange of the gasket is flat and in surface contact with the raised portion of the second end face. Sealed structure.

13. The second end face of the hollow member has a flat surface. The end face of the flange of the gasket has at least one annular protrusion that surrounds the inner circumferential surface of the inner protruding ring portion around its entire circumference, and the protrusion is in surface contact with the flat surface of the second end face. The sealing structure according to claim 11.

14. The raised portion of the flange has a cross-sectional shape that is part of an ellipse when the flange is not compressed. The sealing structure according to claim 13.

15. A plurality of tubular sections are arranged parallel to each other at intervals and do not move relative to each other, each having a first end face and a first hole opening at the first end face. Each of the hollow members is arranged such that the distance between the central axes of the second holes can be changed, and each has a second end face opposite to the first end face of the pipe section, and a second hole opening at the second end face. Each comprises a plurality of gaskets interposed between one of the pipe portions and one of the hollow members, which are compressed between the pipe portion and the second end face of the hollow member to seal the space between the pipe portion and the hollow member. Each gasket has an elastic portion formed from rubber, The aforementioned elastic portion The cylindrical portion is press-fitted into the first hole of the tubular portion, and has an outer circumferential surface and an inner circumferential surface, the outer circumferential surface having a convex ring portion projecting radially outward at its axial center, and at least the convex ring portion making surface contact with the inner circumferential surface of the first hole, A flange integrally connected to the cylindrical portion, concentrically positioned with the cylindrical portion, interposed between the first end face of the tubular portion and the second end face of the hollow member, and compressed between the first end face of the tubular portion and the second end face of the hollow member, comprising: an outer protruding ring portion having an outer circumferential surface having an outer diameter larger than the maximum outer diameter of the outer circumferential surface of the cylindrical portion; an inner protruding ring portion having an inner circumferential surface having an inner diameter smaller than the minimum inner diameter of the inner circumferential surface of the cylindrical portion; and an end face having a portion that makes surface contact with the hollow member, wherein the inner protruding ring portion overlaps the outer protruding ring portion radially, and the end face extends from the outer protruding ring portion to the inner protruding ring portion. The flange is located outside the first hole. Sealed structure.

16. The system further comprises at least one intervening member interposed between a plurality of the aforementioned hollow members. The sealing structure according to claim 15, characterized by the features described above.

17. The intervening member has a rigidity less than that of the hollow member. The sealing structure according to claim 16.

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