Metallic gasket

Abstract

A metal gasket having a planar shape of a ring shape, a longitudinal cross-sectional shape of a K-shaped or a transverse U-shaped, and an inclined surface (6a, 6b) formed at a boundary of an upper surface (3a) of an upper surface portion (3) and an inner peripheral surface (4a) of an inner peripheral portion (4) and a boundary of a lower surface (5a) of a lower surface portion (5) and the inner peripheral surface (4a) of the inner peripheral portion (4), respectively, the inclined surface (6a, 6b) being inclined toward an inner peripheral direction and having a minimum wall thickness portion (t) having a thickness of 3% to 25% of a height of the metal gasket (1), the metal gasket having a mountain-shaped portion (7a, 7b) in the upper surface portion (3) and the lower surface portion (5), respectively, a height from the upper surface (3a) of the upper surface portion (3) to an apex (P) of the mountain-shaped portion (7a) and a height from the lower surface (5a) of the lower surface portion (5) to an apex (Q) of the mountain-shaped portion (7b) being 0.01 mm or more, respectively, the metal gasket having an opening portion (2) formed at an outer peripheral side, a distance (D) between a lower surface (3b) of the upper surface portion (3) and an upper surface (5b) of the lower surface portion (5) being 20% to 90% of the height of the metal gasket (1).

Description

Technical Field

[0001] This invention relates to metal gaskets. More specifically, this invention relates to metal gaskets used, for example, in connecting pipes and equipment in thermal power plants, nuclear power plants, steam engines of steam turbine ships, oil refining lines, petrochemical industry production lines, semiconductor manufacturing lines, etc. Background Technology

[0002] As metal gaskets with excellent heat resistance, hollow metal O-rings and spring-loaded metal C-rings have been proposed (see, for example, Patent Documents 1 and 2). However, these metal gaskets have the disadvantage of requiring a large tightening force to seal between the flanges.

[0003] To reduce the clamping force between flanges, sheath seals with protrusions that abut against the sealing surface of the sealed component have been proposed (e.g., see Patent Document 3), and seals with upper and lower load-concentrating protrusions (e.g., see Patent Document 4). However, it is difficult to manufacture the protrusions with high precision in both the sheath seals with protrusions and the seals with upper and lower load-concentrating protrusions described above, making it difficult to ensure high sealing performance.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 9-177976

[0007] Patent Document 2: Japanese Patent Application Publication No. 11-30333

[0008] Patent Document 3: Japanese Patent Application Publication No. 2000-304132

[0009] Patent Document 4: Japanese Patent Publication No. 2005-517883 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] The present invention was made in view of the above-mentioned prior art, and its object is to provide a metal sealing gasket that can ensure the sealing performance between the metal sealing gasket and the sealed part by fastening the sealed part such as the flange with a small fastening force, and can reduce the force required to further tighten the fastening parts such as bolts.

[0012] Methods for solving problems

[0013] (1) The present invention relates to a metal sealing gasket having an opening on its outer peripheral side, the metal sealing gasket having a ring-shaped planar shape and a U-shaped longitudinal section, characterized in that the metal sealing gasket has an upper surface portion, an inner peripheral portion and a lower surface portion, and inclined surfaces are formed at the boundary between the upper surface of the upper surface portion and the inner peripheral surface of the inner peripheral portion and at the boundary between the lower surface of the lower surface portion and the inner peripheral surface of the inner peripheral portion, respectively. The inclined surfaces are inclined toward the inner peripheral direction and have a minimum wall thickness of 3% to 25% of the height of the metal sealing gasket. The metal sealing gasket has a mountain-shaped portion with a longitudinal section shape of a mountain on the upper surface portion and the lower surface portion, respectively. The height from the upper surface of the upper surface portion to the apex of the mountain-shaped portion and the height from the lower surface of the lower surface portion to the apex of the mountain-shaped portion are both 0.01 mm or more. The metal sealing gasket has an opening between the lower surface of the upper surface portion and the upper surface of the lower surface portion, which is 20% to 90% of the height of the metal sealing gasket.

[0014] (2) The metal gasket according to (1) above, wherein the metal gasket is formed of a metal selected from the group consisting of aluminum, aluminum alloy, stainless steel, Inconel alloy, carbon steel, lead, gold, silver, copper, nickel, tantalum, chromium-molybdenum steel, Monel alloy, titanium and magnesium alloy.

[0015] Invention Effects

[0016] According to the present invention, a metal sealing gasket is provided that can ensure the sealing performance between the metal sealing gasket and the sealed component by fastening the sealed component such as a flange with a small fastening force, and can reduce the force required to further tighten the fastening components such as bolts. Attached Figure Description

[0017] Figure 1 This is a schematic side view illustrating one embodiment of the metal sealing gasket of the present invention.

[0018] Figure 2 yes Figure 1 The figure shown is a schematic cross-sectional view of the XX portion of the metal sealing gasket of the present invention.

[0019] Figure 3 yes Figure 1 The figure shown is a schematic cross-sectional view of the XX portion of the metal sealing gasket of the present invention.

[0020] Figure 4 This is a schematic diagram illustrating the evaluation test apparatus for the metal gaskets used in the various embodiments and comparative examples. Detailed Implementation

[0021] As described above, the metal gasket of the present invention is a metal gasket having an opening on its outer peripheral side, a planar shape that is annular, and a longitudinal cross-sectional shape that is either lateral channel shape or transverse U-shaped.

[0022] The metal gasket of the present invention is characterized by having an upper surface portion, an inner peripheral portion, and a lower surface portion. Inclined surfaces are formed at the boundary between the upper surface of the upper surface portion and the inner peripheral surface of the inner peripheral portion, and at the boundary between the lower surface of the lower surface portion and the inner peripheral surface of the inner peripheral portion, respectively. The inclined surfaces are inclined inward in the direction of the inner periphery and have a minimum wall thickness of 3% to 25% of the height of the metal gasket. The metal gasket has mountain-shaped portions with a longitudinal cross-sectional shape of a mountain on the upper surface portion and the lower surface portion. The height from the upper surface of the upper surface portion to the apex of the mountain-shaped portion and the height from the lower surface of the lower surface portion to the apex of the mountain-shaped portion are both 0.01 mm or more. The metal gasket has an opening portion with a spacing of 20% to 90% of the height of the metal gasket between the lower surface of the upper surface portion and the upper surface of the lower surface portion.

[0023] The metal sealing gasket of the present invention has the above-described structure, and therefore exhibits the following excellent effects: the sealing performance between the metal sealing gasket and the sealed component can be ensured by tightening the flange or other sealed component with a smaller tightening force, and the force required to further tighten the bolt or other fastening components completely can be reduced.

[0024] Furthermore, the aforementioned sealed component refers to a part that is fastened using the metal sealing gasket of the present invention. Representative examples of such sealed components include flanges formed at the ends of tubular bodies such as steel pipes, and connecting portions of equipment devices.

[0025] Hereinafter, the metal sealing gasket of the present invention will be described in detail with reference to the accompanying drawings. However, the metal sealing gasket of the present invention is not limited to the embodiments shown in the accompanying drawings. Other embodiments may also be implemented as long as they are within the scope of the present invention.

[0026] Figure 1 This is a schematic side view illustrating one embodiment of the metal sealing gasket 1 of the present invention. Figure 2 and Figure 3 yes Figure 1 The diagram shows a schematic cross-sectional view of the XX portion of the metal sealing gasket 1 of the present invention. For ease of explanation of the metal sealing gasket 1 of the present invention, [the diagram is shown here]. Figure 2 The reference numerals for the main parts of the metal sealing gasket 1 of the present invention are mainly described in the text. Figure 3 The reference numerals mainly describe the parts of the metal sealing gasket 1 of the present invention other than the main part.

[0027] like Figure 1As shown, the metal sealing gasket 1 has an annular planar shape. Examples of annular planar shapes include circles, squares, rectangles, and other polygons, but the present invention is not limited to these planar shapes. Furthermore, the aforementioned circle includes not only perfect circles but also elongated ellipses, horizontally elongated ellipses, and orbital ellipses. When the metal sealing gasket 1 has a polygonal shape, the corners of the polygon preferably have rounded arcs with a radius of approximately 0.3 mm to 0.5 mm to avoid sharp edges.

[0028] like Figure 2 and Figure 3 As shown, the metal sealing gasket 1 has an upper surface portion 3, an inner peripheral portion 4, and a lower surface portion 5. The upper surface portion 3 is connected to the inner peripheral portion 4, and the inner peripheral portion 4 is connected to the lower surface portion 5.

[0029] like Figure 2 and Figure 3 As shown, the longitudinal cross-sectional shape of the metal gasket 1 is either a lateral channel shape or a transverse U-shape. Among these cross-sectional shapes, the lateral channel shape is preferred from the viewpoint of ensuring the sealing performance between the metal gasket and the sealed component by tightening the flange or other sealed components with a smaller tightening force, and reducing the force required to fully tighten the bolts or other fastening components.

[0030] When the longitudinal cross-sectional shape of the metal gasket 1 is shaped like the Japanese katakana character コ, the inner circumferential surface 4a (the inner surface in the circumferential direction of the opening 2) of the inner circumferential portion 4 of the metal gasket 1 can be as follows: Figure 2 and Figure 3 It can be a flat surface, a curved surface, a surface with angles, or a surface with concavity or convexity.

[0031] When the longitudinal section shape of the metal gasket 1 is a transverse U-shape, the longitudinal section shape of the inner periphery 4 of the metal gasket 1 is an arc shape. For ease of explanation, a metal gasket 1 with a transverse U-shaped longitudinal section means that its longitudinal section is U-shaped. A U-shaped longitudinal section includes the concept that the longitudinal section extending from the opening 2 is transversely C-shaped.

[0032] like Figure 2 As shown, the metal gasket 1 has an opening 2 on its outer peripheral side. The outer peripheral surface 4b of the inner peripheral portion 4 within the opening 2 of the metal gasket 1 can be as follows: Figure 2 As shown, it can be a flat surface, or a curved surface, or a surface with concave and convex shapes.

[0033] exist Figure 2In the embodiment shown, the boundary between the lower surface 3b of the upper surface portion 3 and the outer peripheral surface 4b of the inner peripheral portion 4, and the boundary between the upper surface 5b of the lower surface portion 5 and the outer peripheral surface 4b of the inner peripheral portion 4, are formed with arcs, but they may also have angles or bevels.

[0034] exist Figure 2 In the embodiment shown, the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 are both surfaces parallel to the plane of the metal sealing gasket 1 (the horizontal plane of the metal sealing gasket 1). The lower surface 3b and the upper surface 5b may also be tapered (inclined).

[0035] exist Figure 2 and Figure 3 In the illustrated embodiment, the interior of the opening 2 is hollow. An elastomer (not shown) may also be installed inside the opening 2 if necessary. The elastomer typically has a shape corresponding to the shape of the interior of the opening 2 of the metal gasket 1. The elastomer may also be disposed within the opening 2 in a manner that contacts the inner wall of the opening 2 of the metal gasket 1. A gap may also be provided between the elastomer and the inner wall of the opening 2 by forming an uneven shape on the surface, or by making the longitudinal section shape of the elastomer circular, triangular, or similar shapes.

[0036] Examples of materials constituting the elastomer include, for example, fluororubber, silicone rubber, butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, styrene-butadiene rubber, chloroprene rubber, natural rubber, etc.; olefin-based thermoplastic elastomers, ester-based thermoplastic elastomers, styrene-based thermoplastic elastomers, vinyl chloride-based thermoplastic elastomers, etc.; highly flexible thermoplastic resins such as polytetrafluoroethylene; aluminum alloys; stainless steel; Inconel alloys; carbon steel; lead; gold; silver; copper; nickel; tantalum; chromium-molybdenum steel; Monel alloys; titanium; magnesium alloys, etc., but the present invention is not limited to these examples. Among these materials constituting the elastomer, from the viewpoint of obtaining a metal sealing gasket 1 with excellent heat resistance and capable of ensuring the sealing performance between the metal sealing gasket 1 and the sealed component (not shown) by fastening it with a relatively small tightening force, even under conditions of overheating, fluororubber and silicone rubber are preferred, with fluororubber being more preferred. Furthermore, coil springs, for example, can also be used as the elastomer.

[0037] From the viewpoint of ensuring the sealing performance between the metal gasket and the sealed component by tightening the flange and other sealed components with a smaller tightening force, and reducing the force required to fully tighten fastening components such as bolts, inclined surfaces 6a of the upper surface 3 and 6b of the lower surface 5 are respectively formed at the boundary between the upper surface 3a of the upper surface 3 and the inner circumferential surface 4a of the inner circumferential part 4, and at the boundary between the lower surface 5a of the lower surface 5 and the inner circumferential surface 4a of the inner circumferential part 4, which are inclined toward the inner circumferential direction of the metal gasket 1.

[0038] The angle (inclination angle) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal sealing gasket 1 is not particularly limited, but from the viewpoint that the sealed part can be tightened with a smaller tightening force, it is preferably 20° to 80°, and more preferably 30° to 55°.

[0039] From the viewpoint of ensuring the sealing performance between the metal gasket and the sealed component by tightening the flange or other sealed components with a smaller tightening force, and reducing the force required to fully tighten bolts or other fastening components, the inclined surfaces 6a and 6b of the metal gasket 1 are each formed with a minimum wall thickness t of 3% to 25% of the height H of the metal gasket 1. Figure 2 and Figure 3 As shown, the minimum wall thickness t is the part with the smallest thickness among the inclined surfaces 6a and 6b. Regarding the minimum wall thickness t of the inclined surfaces 6a and 6b, from the viewpoint of improving the sealing performance between the metal gasket 1 and the sealed part, it is more than 3% of the height H of the metal gasket 1, and from the viewpoint of enabling the sealed part to be fastened with a smaller fastening force, it is less than 25%.

[0040] The height H of the metal gasket 1 varies depending on its application, and therefore cannot be generalized. It is preferable to adjust it appropriately according to the application of the metal gasket 1. As an example, the height H of the metal gasket 1 is approximately 1.5mm to 15mm.

[0041] The upper surface 3a of the upper surface portion 3, the inner peripheral surface 4a of the inner peripheral portion 4, and the lower surface 5a of the lower surface portion 5 are generally flat. Without hindering the purpose of the present invention, shapes such as concave-convex shapes, wave shapes, and curved shapes may also be formed on the upper surface 3a, the inner peripheral surface 4a, and the lower surface 5a.

[0042] exist Figure 2 and Figure 3 In the embodiment shown, the upper surface 3a of the upper surface portion 3 and the lower surface 5a of the lower surface portion 5 of the metal sealing gasket 1 are parallel to the metal sealing gasket 1, but they do not necessarily have to be parallel to the metal sealing gasket 1, and they may also have an inclination within the range that does not hinder the purpose of the present invention.

[0043] The metal sealing gasket 1 has a mountain-shaped portion 7a on the upper surface portion 3 and a mountain-shaped portion 7b on the lower surface portion 5. The mountain-shaped portion 7a has a vertex P and a longitudinal section shape that is mountain-shaped, and the mountain-shaped portion 7b has a vertex Q and a longitudinal section shape that is mountain-shaped.

[0044] From the perspective of ensuring the sealing performance between the metal gasket and the sealed component by tightening the flange or other sealed components with a smaller tightening force, and reducing the force required to fully tighten bolts or other fasteners, such as... Figure 3 As shown, vertex P is preferably formed on the extension line of the inclined surface 6a of the upper surface portion 3, and more preferably on the same plane as the extension line of the inclined surface 6a of the upper surface portion 3. Furthermore, from the viewpoint of ensuring the sealing performance between the metal gasket and the sealed component by tightening the flange or other sealed components with a smaller tightening force, and reducing the force required to fully tighten the bolts or other fastening components, vertex Q is preferably formed on the extension line of the inclined surface 6b of the lower surface portion 5, and more preferably on the same plane as the extension line of the inclined surface 6b of the lower surface portion 5.

[0045] The height h1 from the upper surface 3a of the upper surface portion 3 to the apex P of the mountain-shaped portion 7a and the height h2 from the lower surface 5a of the lower surface portion 5 to the apex Q of the mountain-shaped portion 7b are both 0.01 mm or more. The metal sealing gasket 1 contacts the sealed part through the mountain-shaped portions 7a and 7b.

[0046] In this invention, mountain-shaped portions 7a and 7b with a longitudinal cross-sectional shape of a mountain are formed on the metal sealing gasket 1, with heights h1 and h2 of 0.01 mm or more. Therefore, the sealing performance between the metal sealing gasket 1 and the sealed component can be ensured by fastening the sealed component with a smaller fastening force, and the stress required to fully fasten the fastening component can be reduced.

[0047] Furthermore, there is no particular limitation on the upper limit of height h1 and height h2, but from the viewpoint that the sealing performance between the metal gasket 1 and the sealed part can be ensured by tightening the sealed part with a smaller tightening force, and that the stress required to fully tighten the fastening part can be reduced, it is preferred to be 0.3 mm or less, and more preferably 0.2 mm or less.

[0048] like Figure 2 As shown, the apex P of the mountain-shaped portion 7a and the apex Q of the mountain-shaped portion 7b can be pointed or rounded, but from the viewpoint that the sealing performance between the metal gasket 1 and the sealed part can be ensured by tightening the sealed part with a smaller tightening force, and that the stress required to fully tighten the fastening parts can be reduced, it is preferable to be pointed.

[0049] exist Figure 3In this case, the angle θ2 of the mountain-shaped part 7a at the vertex P and the angle θ2 of the mountain-shaped part 7b at the vertex Q are not particularly limited, but from the viewpoint that the sealing performance between the metal sealing gasket 1 and the sealed part can be ensured by tightening the sealed part with a smaller tightening force, and that the stress required to fully tighten the fastening part can be reduced, they are preferably 10° to 160°, more preferably 30° to 150°, further preferably 60° to 140°, and even more preferably 90° to 140°.

[0050] like Figure 2 As shown, the inclined surfaces of the mountain-shaped parts 7a and 7b can be smooth surfaces, wavy surfaces, or surfaces with concave and convex shapes.

[0051] From the perspective of ensuring the sealing performance between the metal gasket and the sealed component by tightening the flange or other sealed components with a smaller tightening force, and reducing the force required to fully tighten bolts or other fasteners, such as... Figure 2 As shown, the apex P of the mountain-shaped portion 7a and the apex Q of the mountain-shaped portion 7b are preferably located in the region R between the midpoint of the width of the metal sealing gasket 1 and the inner peripheral surface 4a of the inner peripheral portion 4 of the metal sealing gasket 1.

[0052] The width of the metal sealing gasket 1 is the length from the inner peripheral surface 4a of the inner peripheral portion 4 to the outer peripheral end 3c of the upper surface portion 3 and the length from the inner peripheral surface 4a of the inner peripheral portion 4 to the outer peripheral end 5c of the lower surface portion 5.

[0053] From the viewpoint of ensuring the sealing performance between the metal gasket 1 and the sealed component by tightening it with a relatively small tightening force, the horizontal positions of the apex P of the mountain-shaped portion 7a and the apex Q of the mountain-shaped portion 7b are preferably as follows: Figure 2 As shown, they exist between the midpoint M of the outer peripheral surface 4b of the inner peripheral portion 4 and the lower surface 3b of the upper surface portion 3, and between the midpoint N of the outer peripheral surface 4b of the inner peripheral portion 4 and the upper surface 5b of the lower surface portion 5.

[0054] Regarding the distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5, from the viewpoint that the sealing performance between the metal gasket 1 and the sealed component can be ensured by tightening the sealed component with a smaller tightening force, and that the force required to fully tighten the fastening component is reduced, it is 20% or more of the height H of the metal gasket 1, preferably 25% or more. From the viewpoint of improving the sealing performance between the metal gasket 1 and the sealed component, it is 90% or less, preferably 80% or less.

[0055] The diameter of the metal gasket 1 on the plane varies depending on its application, so it cannot be generalized. Therefore, it is preferable to determine the appropriate diameter based on the application of the metal gasket 1, which is usually around 2mm to 3mm.

[0056] The width of the metal gasket 1 varies depending on its application, so it cannot be generalized. It is preferable to determine the width appropriately based on the application of the metal gasket 1, usually around 1mm to 15mm.

[0057] Regarding the material of the metal gasket 1, from the viewpoint of ensuring the sealing performance between the metal gasket 1 and the sealed part by fastening the sealed part with a relatively small tightening force, it is preferable to select a metal selected from the group consisting of aluminum, aluminum alloy, stainless steel, Inconel alloy, carbon steel, lead, gold, silver, copper, nickel, tantalum, chromium-molybdenum steel, Monel alloy, titanium, and magnesium alloy. More preferably, it is a metal selected from the group consisting of aluminum, aluminum alloy, stainless steel, and Inconel alloy. Further preferably, it is aluminum, aluminum alloy, or stainless steel. Even more preferably, it is aluminum or aluminum alloy.

[0058] Examples of aluminum alloys include aluminum-iron alloys, aluminum-copper alloys, aluminum-manganese alloys, aluminum-magnesium alloys, aluminum-zinc alloys, and aluminum-nickel alloys, but the present invention is not limited to these examples.

[0059] Examples of stainless steels include SUS304, SUS316, SUS430, SUS630, SUS631, SUS633, and SUS420J2, but the present invention is not limited to these examples.

[0060] Furthermore, other metals besides magnesium used in magnesium alloys can be listed, such as lithium, calcium, aluminum, zinc, titanium, manganese, zirconium, yttrium, tantalum, neodymium, niobium, etc., but the present invention is not limited to this example.

[0061] Alternatively, a plating layer, coating layer (film), etc., may be formed on the surface of the metal gasket 1 without hindering the purpose of the present invention.

[0062] When the metal sealing gasket 1 configured as described above is inserted between the flange or other sealed components and tightened, the mountain-shaped portions 7a and 7b, which have a predetermined height, are pressed by the sealed components, and the metal sealing gasket 1 flexes moderately. Therefore, even when the sealed components are tightened with a relatively small tightening force, the sealing performance between the metal sealing gasket 1 and the sealed components can be ensured. When the fastening components are further tightened completely between the sealed components, the opening 2, which has a gap D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 in a predetermined ratio relative to the height of the metal sealing gasket 1, can reduce the stress required to completely tighten the fastening components.

[0063] Therefore, the metal gasket 1 of the present invention can ensure the sealing performance between the metal gasket 1 and the sealed component by tightening the flange or other sealed component with a relatively small tightening force, and can reduce the stress required to further tighten the fastening components completely, thus enabling the miniaturization and reduction of the number of fastening components. Consequently, the metal gasket 1 of the present invention is preferably used, for example, in connecting pipes and equipment in thermal power plants, nuclear power plants, steam engines of steam turbine ships, oil refining lines, petrochemical industry production lines, semiconductor manufacturing lines, etc.

[0064] Example

[0065] Next, the metal sealing gasket of the present invention will be described in detail with reference to the embodiments, but the present invention is not limited to the embodiments described therein.

[0066] Example 1

[0067] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0068] More specifically, the metal gasket 1 has a circular planar shape, with vertices P and Q located within region R. The height H of the metal gasket 1 is 3.2 mm, the inner diameter is 20 mm, and the outer diameter is 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 is 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at vertices P and Q are 125°, respectively.

[0069] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t that is 15% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 at a distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 that is 40% of the height of the metal gasket 1.

[0070] As to the performance of the aforementioned metal gasket 1, the initial sealing load and the load at the completion of tightening were investigated based on the following method. The results are shown in Table 1.

[0071] Additionally, using Figure 4 The evaluation test apparatus 8 for the metal gasket 1 shown investigated the initial load of the seal and the load at the completion of tightening. Figure 4 This is a schematic diagram of the evaluation test apparatus 8 for the metal sealing gasket 1.

[0072] (1) Sealing start load

[0073] A metal sealing gasket 1 is installed between test plate 9a and test plate 9b inside the evaluation test apparatus 8. Helium gas is injected from nozzle 10a of helium cylinder 10, filling the evaluation test apparatus 8 with atmospheric pressure helium gas.

[0074] Next, a helium leak detector 11 is used to measure the amount of helium leakage from the outside of the metal gasket 1 into the space inside the metal gasket 1. At this time, the compressive load applied to the metal gasket 1 is adjusted so that the helium leakage rate is 1 × 10⁻⁶. -11 Pa·m 3 The compressive load below / s is taken as the sealing start load, and the sealing start load is evaluated based on the following evaluation criteria.

[0075] [Evaluation Criteria]

[0076] 〇: The initial load of the seal is below 1.2kN.

[0077] ×: The initial load of the seal exceeds 1.2kN.

[0078] (2) Load upon completion of fastening

[0079] After the initial load of the seal is measured, the load required for the metal gasket 1 to be fully tightened is measured, and the load at the completion of tightening is evaluated based on the following evaluation criteria.

[0080] [Evaluation Criteria]

[0081] ○: The load when fastening is completed is less than 3.2kN.

[0082] ×: The load at the time of fastening exceeds 3.2kN.

[0083] (3) Comprehensive evaluation

[0084] When the evaluation of the initial sealing load and the load at the completion of tightening are both ○, the overall evaluation is ○; when the evaluation is something other than these, the overall evaluation is ×.

[0085] Example 2

[0086] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0087] More specifically, the metal gasket 1 has a circular planar shape, with vertices P and Q located within region R. The height H of the metal gasket 1 is 3.2 mm, the inner diameter is 20 mm, and the outer diameter is 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 is 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at vertices P and Q are 125°, respectively.

[0088] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t of 3% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 at a distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5, which is 40% of the height of the metal gasket 1.

[0089] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0090] Example 3

[0091] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0092] More specifically, the metal gasket 1 has a circular planar shape, with vertices P and Q located within region R. The height H of the metal gasket 1 is 3.2 mm, the inner diameter is 20 mm, and the outer diameter is 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 is 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at vertices P and Q are 125°, respectively.

[0093] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t that is 15% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 at a distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 that is 40% of the height of the metal gasket 1.

[0094] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0095] Example 4

[0096] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0097] More specifically, the metal gasket 1 has a circular planar shape, with vertices P and Q located within region R. The height H of the metal gasket 1 is 3.2 mm, the inner diameter is 20 mm, and the outer diameter is 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 is 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at vertices P and Q are 125°, respectively.

[0098] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t that is 25% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 at a distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 that is 40% of the height of the metal gasket 1.

[0099] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0100] Example 5

[0101] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0102] More specifically, the metal gasket 1 has a circular planar shape, with vertices P and Q located within region R. The height H of the metal gasket 1 is 3.2 mm, the inner diameter is 20 mm, and the outer diameter is 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 is 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at vertices P and Q are 125°, respectively.

[0103] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t that is 15% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 at a distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 that is 20% of the height of the metal gasket 1.

[0104] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0105] Example 6

[0106] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0107] More specifically, the metal gasket 1 has a circular planar shape, with vertices P and Q located within region R. The height H of the metal gasket 1 is 3.2 mm, the inner diameter is 20 mm, and the outer diameter is 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 is 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at vertices P and Q are 125°, respectively.

[0108] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t that is 15% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 at a distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 that is 40% of the height of the metal gasket 1.

[0109] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0110] Example 7

[0111] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0112] More specifically, the metal gasket 1 has a circular planar shape, with vertices P and Q located within region R. The height H of the metal gasket 1 is 3.2 mm, the inner diameter is 20 mm, and the outer diameter is 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 is 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at vertices P and Q are 125°, respectively.

[0113] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t that is 15% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 where the distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 is 90% of the height of the metal gasket 1.

[0114] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0115] Example 8

[0116] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0117] More specifically, the metal gasket 1 has a circular planar shape, with vertices P and Q located within region R. The height H of the metal gasket 1 is 3.2 mm, the inner diameter is 20 mm, and the outer diameter is 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 is 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at vertices P and Q are 125°, respectively.

[0118] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t that is 15% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.15 mm respectively. The metal gasket 1 is formed with an opening 2 where the distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 is 90% of the height of the metal gasket 1.

[0119] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0120] Example 9

[0121] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0122] More specifically, the metal gasket 1 has a circular planar shape, with vertices P and Q located within region R. The height H of the metal gasket 1 is 3.2 mm, the inner diameter is 20 mm, and the outer diameter is 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 is 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at vertices P and Q are 125°, respectively.

[0123] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t of 3% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 at a distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5, which is 20% of the height of the metal gasket 1.

[0124] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0125] Example 10

[0126] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0127] More specifically, the metal gasket 1 has a circular planar shape, with vertices P and Q located within region R. The height H of the metal gasket 1 is 3.2 mm, the inner diameter is 20 mm, and the outer diameter is 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 is 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 at the vertices P and Q of the mountain-shaped portions 7a and 7b are 125°.

[0128] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t of 3% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 at a distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5, which is 90% of the height of the metal gasket 1.

[0129] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0130] Example 11

[0131] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0132] More specifically, the metal gasket 1 has a circular planar shape, with vertices P and Q located within region R. The height H of the metal gasket 1 is 3.2 mm, the inner diameter is 20 mm, and the outer diameter is 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 is 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at vertices P and Q are 125°, respectively.

[0133] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t that is 25% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 at a distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 that is 20% of the height of the metal gasket 1.

[0134] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0135] Example 12

[0136] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0137] More specifically, the metal gasket 1 has a circular planar shape, with vertices P and Q located within region R. The height H of the metal gasket 1 is 3.2 mm, the inner diameter is 20 mm, and the outer diameter is 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 is 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at vertices P and Q are 125°, respectively.

[0138] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t that is 25% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 where the distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 is 90% of the height of the metal gasket 1.

[0139] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0140] Comparative Example 1

[0141] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0142] More specifically, the metal gasket 1 has a circular planar shape, with vertices P and Q located within region R. The height H of the metal gasket 1 is 3.2 mm, the inner diameter is 20 mm, and the outer diameter is 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 is 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at vertices P and Q are 125°, respectively.

[0143] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t that is 15% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.005 mm respectively. The metal gasket 1 is formed with an opening 2 at a distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 that is 40% of the height of the metal gasket 1.

[0144] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0145] Comparative Example 2

[0146] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0147] More specifically, the metal gasket 1 has a circular planar shape, with a height H of 3.2 mm, an inner diameter of 20 mm, and an outer diameter of 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 are all 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at their vertices P and Q are 125°, respectively.

[0148] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t that is 2% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 at a distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 that is 40% of the height of the metal gasket 1.

[0149] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0150] Comparative Example 3

[0151] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0152] More specifically, the metal gasket 1 has a circular planar shape, with a height H of 3.2 mm, an inner diameter of 20 mm, and an outer diameter of 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 are all 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at their vertices P and Q are 125°, respectively.

[0153] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t that is 26% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 at a distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 that is 40% of the height of the metal gasket 1.

[0154] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0155] Comparative Example 4

[0156] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0157] More specifically, the metal gasket 1 has a circular planar shape, with a height H of 3.2 mm, an inner diameter of 20 mm, and an outer diameter of 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 are all 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at their vertices P and Q are 125°, respectively.

[0158] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t that is 15% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 at a distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 that is 19% of the height of the metal gasket 1.

[0159] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0160] Comparative Example 5

[0161] As a metal sealing gasket, it uses... Figure 2 and Figure 3 The aluminum metal gasket 1 with the longitudinal cross-sectional shape shown.

[0162] More specifically, the metal gasket 1 has a circular planar shape, with a height H of 3.2 mm, an inner diameter of 20 mm, and an outer diameter of 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 are all 0.3 mm. The angles (inclination angles) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 are 45°, and the angles θ2 of the mountain-shaped portions 7a and 7b at their vertices P and Q are 125°, respectively.

[0163] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t that is 40% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 at a distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 that is 91% of the height of the metal gasket 1.

[0164] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0165] Comparative Example 6

[0166] As a metal sealing gasket, the following aluminum metal sealing gasket 1 was used: Figure 3 The longitudinal section shape shown does not have a mountain-shaped part. The plane extends from the vertex P of the mountain-shaped part 7a of the upper surface part 3 to the outer peripheral end 3c of the upper surface part 3, and the plane extends from the vertex Q of the mountain-shaped part 7b of the lower surface part 5 to the outer peripheral end 5c of the lower surface part 5.

[0167] More specifically, in Figure 2 and Figure 3 The metal gasket 1 shown has a circular planar shape, a height H of 3.2 mm, an inner diameter of 20 mm, and an outer diameter of 25 mm. The thickness of the upper surface portion 3, the inner peripheral portion 4, and the lower surface portion 5 of the metal gasket 1 are all 0.3 mm, and the angle (inclination angle) θ1 between the inclined surfaces 6a and 6b and the horizontal plane of the metal gasket 1 is 45°.

[0168] The following metal gasket 1 is used: the inclined surface 6a of the upper surface portion 3 and the inclined surface 6b of the lower surface portion 5 of the metal gasket 1 are respectively formed with a minimum wall thickness t that is 40% of the height H of the metal gasket 1, and the heights h1 and h2 are 0.01 mm respectively. The metal gasket 1 is formed with an opening 2 at a distance D between the lower surface 3b of the upper surface portion 3 and the upper surface 5b of the lower surface portion 5 that is 20% of the height of the metal gasket 1.

[0169] As for the performance of the metal gasket 1 described above, the initial sealing load and the load at the completion of tightening were investigated in the same manner as in Example 1. The results are shown in Table 1.

[0170] [Table 1]

[0171]

[0172] As can be seen from the results shown in Table 1, the metal gaskets obtained in each embodiment can ensure the sealing performance between the metal gasket and the sealed component by tightening the flange and other sealed components with a small tightening force, which can reduce the stress required to further tighten the bolts and other fastening components completely.

[0173] Therefore, the metal gaskets obtained in each embodiment are preferably used, for example, when connecting piping and equipment in thermal power plants, nuclear power plants, steam engines of steam turbine ships, oil refining lines, petrochemical industry production lines, semiconductor manufacturing lines, etc.

[0174] Label Explanation

[0175] 1: Metal sealing gasket; 2: Opening; 3: Upper surface; 3a: Upper surface of the upper surface; 3b: Lower surface of the upper surface; 3c: Outer peripheral end of the upper surface; 4: Inner peripheral; 4a: Inner peripheral surface of the inner peripheral; 4b: Outer peripheral surface of the inner peripheral; 5: Lower surface; 5a: Lower surface of the lower surface; 5b: Upper surface of the lower surface; 5c: Outer peripheral end of the lower surface; 6a: Inclined surface of the upper surface; 6b: Inclined surface of the lower surface; 7a: Mountain-shaped portion of the upper surface; 7b: Mountain-shaped portion of the lower surface; 8: Evaluation test apparatus; 9a: Test bench plate; 9b: Test bench plate; 10: Helium cylinder; 10a: Nozzle; 11: Helium leak detector; D: Spacing between the lower surface of the upper surface and the upper surface of the lower surface; P, Q: Vertices of the mountain-shaped part; R: Area between the midpoint of the width of the metal sealing gasket and the inner circumferential surface of the inner circumference; M: Midpoint of the lower surface of the upper surface; N: Midpoint of the upper surface of the lower surface; h1: Height from the upper surface of the upper surface to the vertex P of the mountain-shaped part; h2: Height from the lower surface of the lower surface to the vertex Q of the mountain-shaped part; t: Minimum wall thickness.

Claims

1. A metal sealing gasket having an opening on its outer peripheral side, the metal sealing gasket having a ring-shaped planar shape and a U-shaped or transversely U-shaped longitudinal section, characterized in that, The metal gasket has an upper surface portion, an inner peripheral portion, and a lower surface portion. Inclined surfaces are formed at the boundary between the upper surface of the upper surface portion and the inner peripheral surface of the inner peripheral portion, and at the boundary between the lower surface of the lower surface portion and the inner peripheral surface of the inner peripheral portion, respectively. These inclined surfaces are inclined inward in the circumferential direction and have a minimum wall thickness of 3% to 25% of the height of the metal gasket. The metal sealing gasket has a mountain-shaped section in longitudinal section on both its upper and lower surfaces. The height from the upper surface of the upper surface to the apex of the mountain-shaped section and the height from the lower surface of the lower surface to the apex of the mountain-shaped section are both 0.01 mm or more. The metal gasket has an opening between the lower surface of the upper surface portion and the upper surface portion, with the distance between them being 20% ​​to 90% of the height of the metal gasket. The apex of the mountain-shaped part of the upper surface exists between the midpoint of the outer peripheral surface of the inner peripheral part and the lower surface of the upper surface, and the apex of the mountain-shaped part of the lower surface exists between the midpoint of the outer peripheral surface of the inner peripheral part and the upper surface of the lower surface.

2. The metal sealing gasket according to claim 1, wherein, Metal gaskets are formed from metals selected from the group consisting of aluminum, aluminum alloys, stainless steel, Inconel, carbon steel, lead, gold, silver, copper, nickel, tantalum, chromium-molybdenum steel, Monel, titanium, and magnesium alloys.

Images