Sealing component

Abstract

The gasket (4) has: a cylindrical main body portion (10) having a communication hole (10a) that communicates the flow path holes (2c, 2c) formed in two fluid devices (2, 2) with each other; and an annular primary sealing portion (11) that protrudes axially outward from the radially inner side of the axially outer end portion of the main body portion (10) and is press-fitted into an annular primary sealing groove (2d) formed in each fluid device (2). In a state before the primary sealing portion (11) is press-fitted into the primary sealing groove (2d), the entire inner peripheral surface (10b) of the main body portion (10) is formed to gradually decrease in diameter from the two axially outer ends toward the axially inner side.

Description

Technical Field

[0001] The present invention relates to a sealing member. Background Art

[0002] In manufacturing processes in various technical fields such as semiconductor manufacturing, medical / pharmaceutical manufacturing, and food processing / chemical industry, in a piping path through which a fluid such as a liquid medicine, high-purity liquid, ultrapure water, or cleaning liquid flows, as a connection structure for connecting flow path holes formed in two fluid devices to each other, for example, a gasket for preventing fluid leakage is employed (for example, refer to Patent Document 1).

[0003] Figure 7 is an axial sectional view of a current gasket. The current gasket 100 has: a cylindrical main body portion 110; an annular primary sealing portion 111 formed to protrude outward in the axial direction on the radially inner side of the axially outer end of the main body portion 110; and an annular secondary sealing portion 112 formed to protrude outward in the axial direction on the radially outer side of the axially outer end of the main body portion 110.

[0004] Figure 8 is an axial sectional view showing a state in which flow path holes 153, 153 formed in two fluid devices 150, 150 are connected to each other by the current gasket 100. The internal space of the main body portion 110 is provided as a communication hole 113 that communicates the flow path holes 153, 153 of the two fluid devices 150, 150 with each other. The primary sealing portion 111 and the secondary sealing portion 112 are press-fitted into an annular primary sealing groove 151 and a secondary sealing groove 152 formed in each fluid device 150. Thereby, the sealing performance between each fluid device 150 and the gasket 100 can be ensured, and fluid leakage to the outside can be prevented.

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-173844 Summary of the Invention

[0006] As Figure 8 shown, the cross-sectional shape of the primary sealing portion 111 is formed to gradually taper from the axially inner end toward the axially outer end. In addition, the cross-sectional shape of the primary sealing groove 151 is inclined along the tapered shape of the primary sealing portion 111. Therefore, when the primary sealing portion 111 is press-fitted into the primary sealing groove 151, sometimes the axially outer end of the primary sealing portion 111 slides outward in the axial direction along the slope of the primary sealing groove 151. If such sliding occurs, a flexural deformation occurs in which the inner peripheral surface 110a of the main body portion 110 is recessed radially outward, causing buckling on the inner peripheral side of the main body portion 110. Then, the contact surface pressure between the axially outer end of the primary sealing portion 111 and the primary sealing groove 151 decreases, and fluid may enter between the primary sealing portion 111 and the primary sealing groove 151 and remain or leak to the outside.

[0007] The present invention is proposed in view of such circumstances, and its object is to provide a sealing member capable of suppressing leakage of fluid.

[0008] (1) The sealing member of the present invention seals and connects the flow path holes formed in two fluid devices respectively, and has: a cylindrical main body portion having a communication hole that communicates the flow path holes with each other; and an annular sealing portion that protrudes from the radially inner side of the axially outer end portion of the main body portion toward the axially outer side and is press-fitted into an annular sealing groove formed at the connection end portion of the flow path hole of one of the fluid devices. In a state before the sealing portion is press-fitted into the sealing groove, that is, in a pre-press state, at least a part of the inner peripheral surface of the main body portion and the inner peripheral surface of the sealing portion other than the axially outer end portion are formed to gradually reduce in diameter from the axially outer side toward the axially inner side.

[0009] According to the present invention, in the pre-press state, at least a part of the inner peripheral surface of the main body portion and the other part of the inner peripheral surface of the sealing portion are formed to protrude toward the radially inner side. Thus, when the sealing portion is press-fitted into the sealing groove, even if the axially outer end of the sealing portion slides relative to the sealing groove, it is possible to suppress the inner peripheral surface of the main body portion from flexurally deforming in a manner of recessing toward the radially outer side. As a result, it is possible to suppress a decrease in the contact surface pressure between the axially outer end of the sealing portion and the sealing groove, and therefore it is possible to suppress fluid from infiltrating between the sealing portion and the sealing groove and leaking to the outside.

[0010] (2) Preferably, in the pre-press state, at least a part of the inner peripheral surface of the main body portion is formed to gradually reduce in diameter from the axially outer side toward the axially inner side.

[0011] In this case, in the pre-press state, at least a part of the inner peripheral surface of the main body portion is formed to protrude toward the radially inner side. Thus, when the sealing portion is press-fitted into the sealing groove, it is possible to further suppress the inner peripheral surface of the main body portion from flexurally deforming in a manner of recessing toward the radially outer side.

[0012] (3) Preferably, in the pre-press state, the entire inner peripheral surface of the main body portion is formed to gradually reduce in diameter from the two axially outer ends toward the axially inner side respectively.

[0013] In this case, in the pre-press state, the entire inner peripheral surface of the main body portion is formed to protrude toward the radially inner side. Thus, when the sealing portion is press-fitted into the sealing groove, it is possible to further suppress the inner peripheral surface of the main body portion from flexurally deforming in a manner of recessing toward the radially outer side.

[0014] (4) Preferably, in the pre-press state, the axially outer end portion of the inner peripheral surface of the sealing portion is formed to gradually reduce in diameter from the axially outer end toward the axially inner end.

[0015] In this case, in the state before press-fitting, the axially outer end portion of the inner peripheral surface of the sealing portion is arranged to be more radially outward than other portions of the inner peripheral surface. Thus, when the sealing portion is press-fitted into the sealing groove, even if the axially outer end of the sealing portion slides relative to the sealing groove, it is possible to suppress the axially outer end portion of the inner peripheral surface of the sealing portion from protruding excessively radially inward. Thereby, it is possible to suppress the fluid flow in the communication hole of the main body portion from being obstructed by the inner peripheral surface of the sealing portion.

[0016] (5) Preferably, in the state before press-fitting, at least a part of the inner peripheral surface of the main body portion is formed to gradually decrease in diameter from the axially outer side toward the axially inner side, and the degree of diameter reduction of the axially outer end portion of the inner peripheral surface of the sealing portion is greater than the degree of diameter reduction of the inner peripheral surface of the main body portion.

[0017] In this case, since the degree of diameter reduction of the axially outer end portion of the inner peripheral surface of the sealing portion is greater than the degree of diameter reduction of the inner peripheral surface of the main body portion, compared with the case where the degree of diameter reduction of the sealing portion is the same as that of the main body portion, it is possible to thicken the radial thickness of the axially outer side of the sealing portion. Thereby, it is possible to further suppress the contact surface pressure between the axially outer end of the sealing portion and the sealing groove from decreasing.

[0018] (6) Preferably, in the state before press-fitting, the entire inner peripheral surface of the sealing portion is formed to gradually decrease in diameter from the axially outer end toward the axially inner end.

[0019] In this case, in the state before press-fitting, the entire inner peripheral surface of the sealing portion is formed to protrude radially inward. Thus, when the sealing portion is press-fitted into the sealing groove, it is possible to further suppress the inner peripheral surface of the sealing portion from being flexurally deformed in a radially outwardly concave manner together with the main body portion, and thus it is possible to further suppress the contact surface pressure between the axially outer end of the sealing portion and the sealing groove from decreasing.

[0020] (7) Preferably, in the state before press-fitting, the entire inner peripheral surface of the main body portion is formed as a curve that protrudes radially inward when observed in an axial cross-section.

[0021] In this case, in the state before press-fitting, the entire inner peripheral surface of the main body portion is formed as a curve that protrudes radially inward when observed in an axial cross-section. Thus, when the sealing portion is press-fitted into the sealing groove, it is possible to further suppress the inner peripheral surface of the main body portion from being flexurally deformed in a radially outwardly concave manner.

[0022] (8) Preferably, in the state where the sealing portion is press-fitted into the sealing groove, the entire inner peripheral surface of the main body portion is formed such that it does not flexurally deform more radially outward than a straight line extending in the axial direction when observed in an axial cross-section.

[0023] In this case, in a state where the sealing portion is press-fitted into the sealing groove, it is possible to suppress the inner peripheral surface of the main body portion from deflecting and deforming more radially outward than a straight line extending in the axial direction. Therefore, it is possible to further suppress a decrease in the contact surface pressure between the axially outer end of the sealing portion and the sealing groove.

[0024] Effects of the Invention

[0025] According to the present invention, leakage of fluid can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is an axial sectional view of a flow path connection structure using a sealing member according to the first embodiment of the present invention.

[0027] Figure 2 is an axial sectional view of a gasket.

[0028] Figure 3 is Figure 2 a partially enlarged sectional view of...

[0029] Figure 4 is an axial sectional view of a flow path connection structure using a sealing member according to the second embodiment of the present invention.

[0030] Figure 5 is an axial sectional view of an inner ring.

[0031] Figure 6 is Figure 5 a partially enlarged sectional view of...

[0032] Figure 7 is an axial sectional view of the current gasket.

[0033] Figure 8 is an axial sectional view showing a state where flow path holes of two fluid devices are connected to each other using the current gasket. DETAILED DESCRIPTION OF THE INVENTION

[0034] [First Embodiment]

[0035] <Overall Structure of the Flow Path Connection Structure>

[0036] Figure 1 is an axial sectional view of a flow path connection structure using a sealing member according to the first embodiment of the present invention. Figure 1 The shown flow path connection structure 1 is used, for example, as a connection structure for connecting flow path holes 2c, 2c formed in two adjacent fluid devices 2, 2 to each other in a piping path for flowing a chemical solution used in a semiconductor manufacturing apparatus. As the fluid device 2 of the present embodiment, a pump, a valve, an accumulator, a filter, a flow meter, a pressure sensor, a piping block, an integrated component that unitizes these devices, an integrated panel, etc. can be cited.

[0037] The flow path connection structure 1 has: annular primary sealing grooves (sealing grooves) 2d and annular secondary sealing grooves 2e respectively formed at the end portions of each fluid device 2; a gasket 4; and a clamping member 5. The gasket 4 is a sealing member that seals and connects the flow path holes 2c, 2c of two fluid devices 2, 2 to each other. Hereinafter, in the present embodiment, the direction from the axial center of the gasket 4 toward both axial sides is referred to as the axial outer side, and the direction from both axial sides of the gasket 4 toward the axial center is referred to as the axial inner side.

[0038] The primary sealing groove 2d of each fluid device 2 is formed in a conical shape cut out in such a manner that the diameter gradually increases from the axial outer end toward the axial inner end at the circumferential surface of the connection end portion of the flow path hole 2c. The secondary sealing groove 2e of each fluid device 2 is located at a position more radially outward than the primary sealing groove 2d in each fluid device 2 and is formed in a cylindrical ring shape.

[0039] The gasket 4 is formed of a synthetic resin material such as polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), or fluororesin (perfluoroalkoxy alkane (PFA), polytetrafluoroethylene (PTFE), or polyvinylidene fluoride (PVDF), etc.). The gasket 4 has: a main body portion 10 formed in a cylindrical shape; a pair of annular primary sealing portions (sealing portions) 11; and a pair of annular secondary sealing portions 12. A communication hole 10a that communicates the flow path holes 2c, 2c of two fluid devices 2, 2 to each other is formed inside the main body portion 10.

[0040] A pair of primary sealing portions 11 are formed to protrude axially outward from the radially inner sides of the outer end portions on both axial sides of the main body portion 10. Each primary sealing portion 11 is formed to taper from the axial inner end toward the axial outer end when observed in the axial cross section. The outer circumferential surface 11a of each primary sealing portion 11 is formed as a conical surface that gradually increases in diameter from the axial outer end toward the axial inner end corresponding to the shape of the primary sealing groove 2d. Thus, each primary sealing portion 11 is press-fitted into the primary sealing groove 2d of the corresponding fluid device 2.

[0041] A pair of secondary sealing portions 12 are formed to protrude axially outward from the radially outer sides of the outer end portions on both axial sides of the main body portion 10. Each secondary sealing portion 12 is formed in a cylindrical ring shape and is press-fitted into the secondary sealing groove 2e of the corresponding fluid device 2.

[0042] According to the above structure, the pair of primary sealing portions 11 and the pair of secondary sealing portions 12 of the gasket 4 are press-fitted into the primary sealing groove 2d and the secondary sealing groove 2e of each fluid device 2, so that the sealing performance of the connection portion between the flow path holes 2c, 2c of two fluid devices 2, 2 can be ensured.

[0043] The clamping member 5 is formed, for example, to have a substantially C-shaped cross-section. In a state where the flow path holes 2c, 2c of the two fluid devices 2, 2 are connected to each other by the gasket 4, the two fluid devices 2, 2 are connected to each other. Specifically, the clamping member 5 axially clamps and fastens the flange portions 2f, 2f formed at the ends of the respective fluid devices 2, 2. Thereby, the sealing state in which the gasket 4 is pressed into the primary sealing groove 2d and the secondary sealing groove 2e of each fluid device 2 can be maintained. In addition to the clamping member 5, the flow path connection structure 1 may have other connection units such as bolts and nuts.

[0044] However, when the primary sealing portion 11 and the secondary sealing portion 12 of the gasket 4 are pressed into the primary sealing groove 2d and the secondary sealing groove 2e of each fluid device 2, the outer axial end of the primary sealing portion 11 may sometimes slide axially outward along the slope of the primary sealing groove 2d. If such sliding occurs, the inner peripheral surface 10b of the main body portion 10 deflects and deforms radially outward, causing buckling on the inner peripheral side of the main body portion 10. In the present embodiment, in the pressed state where the primary sealing portion 11 and the secondary sealing portion 12 are pressed into the primary sealing groove 2d and the secondary sealing groove 2e, the inner peripheral surface 10b of the main body portion 10 is formed in a shape that suppresses deflection and deformation in a radially outwardly concave manner. Hereinafter, the detailed shape will be described.

[0045] <Shape of the inner peripheral side of the gasket>

[0046] Figure 2 is an axial sectional view of the gasket 4, showing the state before the primary sealing portion 11 and the secondary sealing portion 12 are pressed into the primary sealing groove 2d and the secondary sealing groove 2e (refer to Figure 1 ), that is, the state before pressing. In Figure 2 , the entire inner peripheral surface 10b of the main body portion 10 of the gasket 4 is formed to gradually reduce in diameter from the two outer axial ends toward the axial inner side.

[0047] In the present embodiment, the entire inner peripheral surface 10b of the main body portion 10 is formed as a curve 10b1 that protrudes most radially inward at the axial center when viewed in the axial cross-section. The curve 10b1 of the inner peripheral surface 10b becomes a straight line 10b2 extending in the axial direction by deflecting and deforming radially outward in the pressed state shown in Figure 1 . That is, the radius of curvature r1 of the curve 10b1 is set such that the shape after the deflection and deformation radially outward becomes the straight line 10b2.

[0048] Figure 3 is Figure 2 a partially enlarged sectional view. In Figure 3In [the figure], the entire inner circumferential surface 11b of the primary seal portion 11 of the gasket 4 is formed to gradually reduce in diameter from the axially outer end toward the axially inner end. In the present embodiment, the entire inner circumferential surface 11b of the primary seal portion 11 is formed as a curve that protrudes most radially inward at the axially inner end when observed in a cross-section in the axial direction.

[0049] The degree of diameter reduction of the axially outer end portion 11c of the inner circumferential surface 11b of the primary seal portion 11 is greater than the degree of diameter reduction of the inner circumferential surface 10b of the main body portion 10. That is, the radius of curvature r2 of the axially outer end portion 11c of the inner circumferential surface 11b of the primary seal portion 11 is smaller than the radius of curvature r1 of the inner circumferential surface 10b of the main body portion 10.

[0050] The entire other portion 11d of the inner circumferential surface 11b of the primary seal portion 11, excluding the axially outer end portion 11c, is formed to gradually reduce in diameter from the axially outer end toward the axially inner end. In the present embodiment, the entire other portion 11d is formed as a curve 11d1 that protrudes most radially inward at the axially inner end when observed in a cross-section in the axial direction. The radius of curvature r3 of the curve 11d1 is the same as the radius of curvature r1 of the inner circumferential surface 10b of the main body portion 10. Therefore, the curve 11d1 Figure 1 is deflected and deformed radially outward in the press-fitted state shown to become a straight line 11d2 extending in the axial direction. That is, the radius of curvature r3 of the curve 11d1 is set such that the shape after the deflection and deformation radially outward becomes the straight line 11d2.

[0051] <Function and Effect of the First Embodiment>

[0052] According to the gasket 4 of the present embodiment, in the state before press-fitting, the entire inner circumferential surface 10b of the main body portion 10 is formed to gradually reduce in diameter from the two axially outer ends toward the axially inner side. That is, in the state before press-fitting, the entire inner circumferential surface 10b of the main body portion 10 is formed to protrude radially inward. Thus, when the primary seal portion 11 is press-fitted into the primary seal groove 2d, even if the axially outer end of the primary seal portion 11 slides axially outward along the slope of the primary seal groove 2d, it is possible to suppress the inner circumferential surface 10b of the main body portion 10 from being deflected and deformed in a manner that depresses radially outward. As a result, it is possible to suppress a decrease in the contact surface pressure between the axially outer end of the primary seal portion 11 and the primary seal groove 2d, and thus it is possible to suppress fluid from entering between the primary seal portion 11 and the primary seal groove 2d and leaking to the outside.

[0053] Further, in the state before press-fitting, the entire inner peripheral surface 11b of the primary seal portion 11 is formed to gradually decrease in diameter from the outer axial end toward the inner axial end. That is, in the state before press-fitting, the entire inner peripheral surface 11b of the primary seal portion 11 is formed to protrude toward the radially inner side. Thus, when the primary seal portion 11 is press-fitted into the primary seal groove 2d, it is possible to suppress further flexural deformation of the inner peripheral surface 11b of the primary seal portion 11 and the main body portion 10 in a manner of being recessed toward the radially outer side. As a result, it is possible to further suppress a decrease in the contact surface pressure between the outer axial end of the primary seal portion 11 and the primary seal groove 2d.

[0054] Further, in the state before press-fitting, the axially outer end portion 11c of the inner peripheral surface 11b of the primary seal portion 11 is formed to gradually decrease in diameter from the outer axial end toward the inner axial end. That is, in the state before press-fitting, the axially outer end portion 11c of the inner peripheral surface 11b of the primary seal portion 11 is arranged to be more radially outer than the other portion 11d of the inner peripheral surface 11b. Thus, when the primary seal portion 11 is press-fitted into the primary seal groove 2d, even if the outer axial end of the primary seal portion 11 slides relative to the primary seal groove 2d, it is possible to suppress excessive protrusion of the axially outer end portion 11c of the inner peripheral surface 11b of the primary seal portion 11 toward the radially inner side. Thereby, it is possible to suppress the flow of the fluid in the communication hole 10a of the main body portion 10 from being obstructed by the inner peripheral surface 11b of the primary seal portion 11.

[0055] Further, the degree of diameter reduction of the axially outer end portion 11c of the inner peripheral surface 11b of the primary seal portion 11 is greater than the degree of diameter reduction of the inner peripheral surface 10b of the main body portion 10. Therefore, compared with the case where the degree of diameter reduction of the primary seal portion 11 is the same as that of the main body portion 10, it is possible to thicken the radial thickness on the outer axial side of the primary seal portion 11. Thereby, it is possible to further suppress a decrease in the contact surface pressure between the outer axial end of the primary seal portion 11 and the primary seal groove 2d.

[0056] Further, in the state before press-fitting, the entire inner peripheral surface 10b of the main body portion 10 is formed into a curve 10b1 that protrudes toward the radially inner side. Thus, when the primary seal portion 11 is press-fitted into the primary seal groove 2d, it is possible to further suppress flexural deformation of the inner peripheral surface 10b of the main body portion 10 in a manner of being recessed toward the radially outer side.

[0057] Further, the curve 10b1 of the inner peripheral surface 10b of the main body portion 10 and the curve 11d1 of the other portion 11d of the inner peripheral surface 11b of the primary seal portion 11 are formed such that they are flexurally deformed toward the radially outer side and become straight lines 10b2 and 11d2 in the press-fitted state. Thereby, it is possible to further suppress flexural deformation of the inner peripheral surface 10b of the main body portion 10 in a manner of being recessed toward the radially outer side in the press-fitted state. As a result, it is possible to further suppress a decrease in the contact surface pressure between the outer axial end of the primary seal portion 11 and the primary seal groove 2d.

[0058] [Second Embodiment]

[0059] <Overall Structure of Flow Path Connection Structure>

[0060] Figure 4 is an axial sectional view of a flow path connection structure using the sealing member according to the second embodiment of the present invention. In Figure 4 this, the flow path connection structure 20 of the present embodiment is used, for example, in the same manner as the first embodiment, for a piping path through which a chemical solution (fluid) used in a semiconductor manufacturing apparatus flows. The flow path connection structure 20 has a joint body 22, a union nut 23, and an inner ring 24. Hereinafter, in the present embodiment, for convenience, the Figure 4 right side of Figure 4 is referred to as the axially outer side, and the Figure 5 left side of Figure 6 is referred to as the axially inner side ( Figure 5 、 Figure 6 is the same).

[0061] The inner ring 24 is formed in a cylindrical shape from a synthetic resin material such as polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), or fluororesin (perfluoroalkoxy alkane (PFA), polytetrafluoroethylene (PTFE), or polyvinylidene fluoride (PVDF), etc.). The inner ring 24 has: a main body portion 25, which is formed in a cylindrical shape; a bulging portion 26, which is formed at the axially inner end portion of the main body portion 25; and a connecting portion 27, which is formed at the axially outer end portion of the main body portion 25.

[0062] The bulging portion 26 is formed to bulge radially outward at the axially inner end portion of the main body portion 25. The bulging portion 26 is press-fitted into the front end portion of a tube 28 made of a synthetic resin material (such as PFA) to expand the front end portion. The connecting portion 27 is connected to the end portion of the joint body 22 to seal the connection portion. In addition, the structure of the connecting portion 27 will be described later. A communication hole 25a is formed inside the main body portion 25 to communicate a flow path hole 22c formed inside the joint body 22 and a flow path hole 28a formed inside the tube 28.

[0063] The joint body 22 is formed in a cylindrical shape from a synthetic resin material such as PVC, PP, PE, or fluororesin (PFA, PTFE, etc.). The inner diameter of the joint body 22 is set to be approximately the same size as the inner diameter of the main body portion 25 of the inner ring 24 so as not to hinder the movement of the chemical solution. A socket portion 22a is formed at the end portion of the joint body 22. The inner ring 24 press-fitted into the front end portion of the tube 28 is fitted into the inner circumference of the socket portion 22a. Thus, the end portion of the joint body 22 is mounted on the outer circumference of the front end portion of the tube 28. An external thread portion 22b is formed on the outer circumference of the socket portion 22a.

[0064] The joint body 22 has an annular primary seal groove (seal groove) 22d and an annular secondary seal groove 22e formed radially inward of the socket portion 22a. The primary seal groove 22d is formed in a conical shape cut in such a manner that the diameter gradually increases from the outer axial end toward the inner axial end on the circumferential surface of the connecting end portion of the flow path hole 22c. The secondary seal groove 22e is formed in a cylindrical ring shape at a position radially outside the primary seal groove 22d in the joint body 22.

[0065] The coupling nut 23 is formed in a cylindrical shape from a synthetic resin material such as PVC, PP, PE, or fluororesin (PFA, PTFE, etc.). The coupling nut 23 has: an internal thread portion 23a formed on the inner circumference of the outer axial end portion; and a pressing portion 23b formed to protrude radially inward at the inner axial end portion. The internal thread portion 23a is fastened to the external thread portion 22b of the joint body 22. By this fastening, the coupling nut 23 is attached to the joint body 22, and the inner axial end portion of the pressing portion 23b presses the outer circumferential surface of the pipe 28 by the bulging portion 26 of the inner ring 24.

[0066] According to the above structure, by fastening the internal thread portion 23a of the coupling nut 23 to the external thread portion 22b of the joint body 22, the sealing performance at the mounting portion of the socket portion 22a of the joint body 22 and the front end portion of the pipe 28 can be ensured, and the pulling out of the pipe 28 can be prevented.

[0067] The connecting portion 27 of the inner ring 24 has an annular primary seal portion (seal portion) 31 and an annular secondary seal portion 32.

[0068] The primary seal portion 31 is formed to protrude radially outward from the radially inner side of the outer axial end portion of the main body portion 25 toward the axial outside. Further, the primary seal portion 31 is formed to taper from the inner axial end toward the outer axial end when observed in the axial cross section. The outer circumferential surface 31a of the primary seal portion 31 is a conical surface formed in such a manner that the diameter gradually increases from the outer axial end toward the inner axial end corresponding to the shape of the primary seal groove 22d. Thus, the primary seal portion 31 is press-fitted into the primary seal groove 22d of the joint body 22.

[0069] The secondary seal portion 32 is formed to protrude radially outward from the radially outer side of the outer axial end portion of the main body portion 25 toward the axial outside. The secondary seal portion 32 is formed in a cylindrical ring shape and is press-fitted into the secondary seal groove 22e of the joint body 22.

[0070] According to the above structure, when the coupling nut 23 is tightened, the primary seal portion 31 and the secondary seal portion 32 of the inner ring 24 are respectively pressed into the primary seal groove 22d and the secondary seal groove 22e of the joint body 22. Thereby, the sealing performance of the connecting portion between the inner ring 24 and the joint body 22 can be ensured. Therefore, the inner ring 24 functions as a sealing member that seals and connects the flow path hole 28a of the pipe (fluid equipment) 28 and the flow path hole 22c of the joint body (fluid equipment) 22.

[0071] However, when the primary seal portion 31 and the secondary seal portion 32 of the inner ring 24 are pressed into the primary seal groove 22d and the secondary seal groove 22e of the joint body 22 by tightening the coupling nut 23, sometimes the axial outer end of the primary seal portion 31 slides axially outward along the slope of the primary seal groove 22d. If such sliding occurs, the inner peripheral surface 25b of the main body portion 25 flexes and deforms radially outward in such a manner that the inner peripheral side of the main body portion 25 buckles. In the present embodiment, in the pressed state where the primary seal portion 31 and the secondary seal portion 32 are pressed into the primary seal groove 22d and the secondary seal groove 22e, the inner peripheral surface 25b of the main body portion 25 is formed into a shape that suppresses flexure deformation in a manner of denting radially outward. Hereinafter, the detailed shape thereof will be described.

[0072] <Structure on the inner peripheral side of the inner ring>

[0073] Figure 5 is an axial sectional view of the inner ring 24, showing the state before the primary seal portion 31 and the secondary seal portion 32 are pressed into the primary seal groove 22d and the secondary seal groove 22e (refer to Figure 4 ), that is, the state before pressing. In Figure 5 , the entire inner peripheral surface 25b of the main body portion 25 of the inner ring 24 is formed to gradually reduce in diameter from the two axial outer ends toward the axial inner side.

[0074] In the present embodiment, the entire inner peripheral surface 25b of the main body portion 25 is formed into a curve 25b1 that protrudes most radially inward at the axial center when observed in the axial section. The curve 25b1 of the inner peripheral surface 25b flexes and deforms radially outward in the pressed state shown in Figure 4 to become a straight line 25b2 extending axially. That is, the radius of curvature r11 of the curve 25b1 is set such that the shape after flexure deformation radially outward becomes the straight line 25b2.

[0075] Figure 6 is Figure 5 a partially enlarged sectional view of the main part. In Figure 6In [description], the entire inner circumferential surface 31b of the primary seal portion 31 of the inner ring 24 is formed to gradually reduce in diameter from the axial outer end toward the axial inner end. In the present embodiment, the entire inner circumferential surface 31b of the primary seal portion 31 is formed as a curve that protrudes most radially inward at the axial outer end when observed in an axial cross-section.

[0076] The degree of diameter reduction of the axial outer end portion 31c of the inner circumferential surface 31b of the primary seal portion 31 is greater than the degree of diameter reduction of the inner circumferential surface 25b of the main body portion 25. That is, the radius of curvature r12 of the axial outer end portion 31c of the inner circumferential surface 31b of the primary seal portion 31 is smaller than the radius of curvature r11 of the inner circumferential surface 25b of the main body portion 25.

[0077] The entire other portion 31d of the inner circumferential surface 31b of the primary seal portion 31, except for the axial outer end portion 31c, is formed to gradually reduce in diameter from the axial outer end toward the axial inner end. In the present embodiment, the entire other portion 31d is formed as a curve 31d1 that protrudes most radially inward at the axial inner end when observed in an axial cross-section. The radius of curvature r13 of the curve 31d1 is the same as the radius of curvature r11 of the inner circumferential surface 25b of the main body portion 25. Therefore, the curve 31d1 is Figure 4 formed to be elastically deformed and bent radially outward to become a straight line 31d2 extending in the axial direction in the press-fitted state shown. That is, the radius of curvature r13 of the curve 31d1 is set such that the shape after the elastic deformation radially outward becomes a straight line 31d2.

[0078] <Effects of the Second Embodiment>

[0079] According to the inner ring 24 of the present embodiment, in the state before press-fitting, the entire inner circumferential surface 25b of the main body portion 25 is formed to gradually reduce in diameter from the two axial outer ends toward the axial inner side. That is, in the state before press-fitting, the entire inner circumferential surface 25b of the main body portion 25 is formed to protrude radially inward. Thus, when the primary seal portion 31 is press-fitted into the primary seal groove 22d, even if the axial outer end of the primary seal portion 31 slides axially outward along the slope of the primary seal groove 22d, it is possible to suppress the inner circumferential surface 25b of the main body portion 25 from being elastically deformed and recessed radially outward. As a result, it is possible to suppress a decrease in the contact surface pressure between the axial outer end of the primary seal portion 31 and the primary seal groove 22d, and thus it is possible to suppress fluid from entering between the primary seal portion 31 and the primary seal groove 22d and leaking to the outside.

[0080] In addition, in the state before press-fitting, the entire inner peripheral surface 31b of the primary seal portion 31 is formed to gradually decrease in diameter from the axially outer end toward the axially inner end. That is, in the state before press-fitting, the entire inner peripheral surface 31b of the primary seal portion 31 is formed to protrude toward the radially inner side. Thus, when the primary seal portion 31 is press-fitted into the primary seal groove 22d, it is possible to further suppress the inner peripheral surface 31b of the primary seal portion 31 and the main body portion 25 from flexurally deforming in a manner of denting toward the radially outer side. As a result, it is possible to further suppress the decrease in the contact surface pressure between the axially outer end of the primary seal portion 31 and the primary seal groove 22d.

[0081] In addition, in the state before press-fitting, the axially outer end portion 31c of the inner peripheral surface 31b of the primary seal portion 31 is formed to gradually decrease in diameter from the axially outer end toward the axially inner end. That is, in the state before press-fitting, the axially outer end portion 31c of the inner peripheral surface 31b of the primary seal portion 31 is arranged to be more radially outer than the other portion 31d of the inner peripheral surface 31b. Thus, when the primary seal portion 31 is press-fitted into the primary seal groove 22d, even if the axially outer end of the primary seal portion 31 slides relative to the primary seal groove 22d, it is possible to suppress the axially outer end portion 31c of the inner peripheral surface 31b of the primary seal portion 31 from protruding excessively toward the radially inner side. Thereby, it is possible to suppress the flow of the fluid at the communication hole 25a of the main body portion 25 from being obstructed by the inner peripheral surface 31b of the primary seal portion 31.

[0082] In addition, the degree of diameter reduction of the axially outer end portion 31c of the inner peripheral surface 31b of the primary seal portion 31 is greater than the degree of diameter reduction of the inner peripheral surface 25b of the main body portion 25. Therefore, compared with the case where the degree of diameter reduction of the primary seal portion 31 is set to be the same as the degree of diameter reduction of the main body portion 25, it is possible to thicken the radial thickness on the axially outer side of the primary seal portion 31. Thereby, it is possible to further suppress the decrease in the contact surface pressure between the axially outer end of the primary seal portion 31 and the primary seal groove 22d.

[0083] In addition, in the state before press-fitting, the entire inner peripheral surface 25b of the main body portion 25 is formed as a curve 25b1 that protrudes toward the radially inner side. Thus, when the primary seal portion 31 is press-fitted into the primary seal groove 22d, it is possible to further suppress the inner peripheral surface 25b of the main body portion 25 from flexurally deforming in a manner of denting toward the radially outer side.

[0084] In addition, the curve 25b1 of the inner peripheral surface 25b of the main body portion 25 and the curve 31d1 of the other portion 31d of the inner peripheral surface 31b of the primary seal portion 31 are formed to flexurally deform toward the radially outer side and become straight lines 25b2 and 31d2 in the press-fitted state. Thereby, it is possible to further suppress the inner peripheral surface 25b of the main body portion 25 from flexurally deforming in a manner of denting toward the radially outer side in the press-fitted state. As a result, it is possible to further suppress the decrease in the contact surface pressure between the axially outer end of the primary seal portion 31 and the primary seal groove 22d.

[0085] [Others]

[0086] In addition to semiconductor manufacturing apparatuses, the sealing members (gasket 4, inner ring 24) of the present invention can be applied to fields such as the liquid crystal / organic EL field, the medical / medicine field, or the automotive-related field. In addition, the present invention can also be applied to a sealing member having only a primary sealing portion.

[0087] The curves 10b1, 25b1 of the inner peripheral surfaces 10b, 25b of the main body portions 10, 25 of the sealing member only need to be formed so as not to be deflected and deformed more radially outward than the straight lines 10b2, 25b2 in the press-fitted state. For example, the curves 10b1, 25b1 of the inner peripheral surfaces 10b, 25b can be formed as curves convex radially inward in the press-fitted state.

[0088] In the state before press-fitting, the curves 10b1, 25b1 of the inner peripheral surfaces 10b, 25b of the main body portions 10, 25 are formed to be most convex radially inward at the axial center, but can also be formed to be most convex radially inward at any position other than the two axial outer ends.

[0089] In the state before press-fitting, at least a part of the other parts 11d, 31d of the inner peripheral surfaces 10b, 25b of the main body portions 10, 25 and the inner peripheral surfaces 11b, 31b of the primary sealing portions 11, 31 only need to be formed to gradually reduce in diameter from the axial outer side toward the axial inner side. For example, it can be formed such that only a part of the inner peripheral surfaces 10b, 25b of the main body portions 10, 25 gradually reduces in diameter from the axial outer side toward the axial inner side. In addition, it can be formed such that only a part or the whole of the other parts 11d, 31d of the inner peripheral surfaces 11b, 31b of the primary sealing portions 11, 31 gradually reduces in diameter from the axial outer side toward the axial inner side.

[0090] In the state before press-fitting, the entire axially outer end portions 11c, 31c of the inner peripheral surfaces 11b, 31b of the primary sealing portions 11, 31 can be formed as straight lines extending in the axial direction when viewed in the axial cross-section.

[0091] In addition, in the state before press-fitting, the inner peripheral surfaces 11b, 31b of the primary sealing portions 11, 31 can be formed as straight lines extending throughout the axial direction when viewed in the axial cross-section.

[0092] In the state before press-fitting, if the inner peripheral surfaces 10b, 25b of the main body portions 10, 25 are formed to gradually reduce in diameter from the axial outer side toward the axial inner side, they can be formed in a shape other than a curve (for example, a tapered line). Similarly, if the inner peripheral surfaces 11b, 31b of the primary sealing portions 11, 31 are formed to gradually reduce in diameter from the axial outer side toward the axial inner side, they can be formed in a shape other than a curve (for example, a tapered line).

[0093] It should be understood that the embodiments disclosed herein are illustrative in all aspects and not restrictive. The scope of the present invention is not the above-mentioned scope, but is represented by the claims, which are intended to also include the scope equivalent to the claims and all modifications within the scope.

[0094] Description of Reference Numerals

[0095] 2 Fluid Equipment

[0096] 2c Flow Path Hole

[0097] 2d Primary Sealing Groove (Sealing Groove)

[0098] 4 Gasket (Sealing Component)

[0099] 10 Main Body

[0100] 10a Communication Hole

[0101] 10b Inner Peripheral Surface

[0102] 10b1 Curve

[0103] 10b2 Straight Line

[0104] 11 Primary Sealing Portion (Sealing Portion)

[0105] 11b Inner Peripheral Surface

[0106] 11c Axial Outer End

[0107] 11d Other Parts

[0108] 22 Joint Body (Fluid Equipment)

[0109] 22c Flow Path Hole

[0110] 22d Primary Sealing Groove (Sealing Groove)

[0111] 24 Inner Ring (Sealing Component)

[0112] 25 Main Body

[0113] 25a Communication Hole

[0114] 25b Inner Peripheral Surface

[0115] 25b1 Curve

[0116] 25b2 Straight Line

[0117] 28 Pipe (Fluid Equipment)

[0118] 28a Flow Path Hole

[0119] 31 Primary Sealing Portion (Sealing Portion)

[0120] Inner peripheral surface of 31b

[0121] Axial outer end of 31c

[0122] Other part of 31d

Claims

1. A sealing member that seals and connects flow path holes formed in two fluid devices respectively, wherein the sealing member has: a cylindrical main body portion having a communication hole that communicates the flow path holes with each other; and an annular sealing portion that protrudes axially outward from the radially inner side of the axially outer end portion of the main body portion and is press-fitted into an annular sealing groove formed at the connecting end portion of the flow path hole of one of the fluid devices, in a state before the sealing portion is press-fitted into the sealing groove, i.e., the pre-press state, the entire inner peripheral surface of the main body portion is formed in a curve that gradually reduces in diameter from the two axially outer ends toward the axially inner side and protrudes most radially inward at the axial center when observed in a cross-section in the axial direction, the radius of curvature of the curve is set such that in a state where the sealing portion is press-fitted into the sealing groove, the curve becomes a straight line extending in the axial direction through flexural deformation toward the radially outer side when observed in a cross-section in the axial direction.

2. The sealing member according to claim 1, wherein in the pre-press state, the axially outer end portion of the inner peripheral surface of the sealing portion is formed to gradually reduce in diameter from the axially outer end toward the axially inner end.

3. The sealing member according to claim 2, wherein in the pre-press state, at least a part of the inner peripheral surface of the main body portion is formed to gradually reduce in diameter from the axially outer side toward the axially inner side, and the degree of diameter reduction of the axially outer end portion of the inner peripheral surface of the sealing portion is greater than the degree of diameter reduction of the inner peripheral surface of the main body portion.

4. The sealing member according to claim 1, wherein in the pre-press state, the entire inner peripheral surface of the sealing portion is formed to gradually reduce in diameter from the axially outer end toward the axially inner end.

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