JP6804896B2 - Metal gasket - Google Patents

Description

The present invention relates to a metal gasket. Specifically, a metal capable of forming a wide contact width with respect to a mating sealing surface, having excellent restoring force characteristics, and obtaining good sealing performance even if cavities are formed on the mating sealing surface. Regarding gaskets.

In recent years, in many industries including the automobile industry, there are many cases where products are assembled using casting materials. For example, cast parts made of die-cast aluminum are used in automobile parts such as engines.

In cast parts, voids between metal particles may remain inside the parts even after sintering and molding, and cavities may be formed. Since the structure of the part near the surface of the cast part is dense, the cavities are not exposed to the outside. However, the surface of the cast part may be finished by cutting after molding in order to improve dimensional accuracy and flatness. At this time, the cavities inside the cast parts may be exposed on the surface by cutting, and concave portions may be formed by the cavities.

If such a concave portion is formed on the mating sealing surface of the gasket, there is a problem that the sealing property of the gasket cannot be sufficiently obtained. That is, as described above, the bead portion of the gasket is deformed by being compressed by the bolt axial force between the two members, and the gasket is brought into close contact with the mating sealing surface by the reaction force generated in the bead portion at this time. At this time, if a concave portion exists so as to straddle the contact surface with the bead portion, leakage of the sealing fluid may occur through the concave portion.

In this regard, it is possible to apply resin or liquid rubber (FIPG) to the mating sealing surface to seal the gap with the gasket, or replace the cast part itself with one that is less affected by the cavities. (Patent Document 1). However, in recent years, with the miniaturization and weight reduction of products, the number of products having a shape that is difficult to mold has increased, and it has become difficult to manage the cavities of cast parts. For this reason, measures against cavities have been required for the gasket itself.

Therefore, various gaskets have been proposed in which measures are taken against the case where the condition of the mating sealing surface is poor, such as the formation of a concave portion due to the cavities. For example, by providing an arcuate portion having a small curvature that is convex toward the mating seal surface, a wide contact width is formed with respect to the mating sealing surface, and the concave portion formed on the mating sealing surface is covered. Gaskets have been proposed (Patent Documents 2 and 3). However, these gaskets are gaskets made of a rubber-like elastic body, and are not metal gaskets in which a bead portion is formed on a metal substrate.

As a metal gasket, a metal gasket has been proposed in which a wide contact width can be obtained by providing a bead in which a plurality of flat bead surfaces are continuously formed via a bent portion. (Patent Document 4).

Japanese Unexamined Patent Publication No. 2001-113404 Japanese Unexamined Patent Publication No. 2011-94667 Japanese Unexamined Patent Publication No. 2011-117466 Japanese Patent No. 5450575

By the way, as a countermeasure against a bad condition of the mating sealing surface such as a concave portion formed by a casting cavity, it is preferable not only to widen the contact width but also to have excellent restoring force characteristics of the gasket.

If the restoring force characteristics are excellent, the sealing pressure is high, the followability to the mating sealing surface is high, and the concave portion of the mating sealing surface can be closed more reliably.

Therefore, the present invention provides a metal gasket that can form a wide contact width with respect to the mating sealing surface, has excellent restoring force characteristics, and can obtain good sealing performance even if cavities are formed on the mating sealing surface. That is the issue.

Other problems of the present invention will be clarified by the following description.

The above problems are solved by the following inventions.

1. 1.
At least one convex one-sided bead portion is formed on one surface side of the gasket body to form a sealing portion in contact with the mating sealing surface, and at least one to form a sealing portion in contact with the mating sealing surface on the other surface side. Two convex bead portions on the other side are formed,
The one-sided bead portion and the other-side bead portion are metal gaskets that are connected by a connecting portion to form a continuous strip.
The one-sided bead portion is an arc-shaped portion that is convex toward one surface side of the gasket body, and a hem rising portion that rises diagonally from the gasket body toward the arc-shaped portion at one hem portion of the arc-shaped portion. The connection portion between the arcuate portion and the hem rising portion is formed so as to be convex toward the convex side of the one-sided bead portion.
The other-side bead portion has an arc-shaped portion that is convex toward the other surface side of the gasket body and a hem that rises diagonally from the gasket body toward the arc-shaped portion at one hem of the arc-shaped portion. It has a rising portion, and the connecting portion between the arcuate portion and the hem rising portion is formed so as to be convex toward the convex side of the bead portion on the other surface side.
The arcuate portion of the one-sided bead portion and the connecting portion of the connecting portion are formed so as to be convex toward the convex side of the one-sided bead portion, and the arc-shaped portion of the other-side bead portion is formed. A metal gasket characterized in that the connecting portion between the portion and the connecting portion is formed so as to be convex toward the convex side of the other surface side bead portion.
2. 2.
The plastic strain over the entire width of each arcuate portion is lower than that of each connection portion, and the surface pressure distribution of each arcuate portion in the compressed state is flat and wide over the width direction of each arcuate portion. The metal gasket according to 1 above.
3. 3.
The metal gasket according to 1 or 2, wherein the distance between the connection portions arranged on both sides of the arcuate portion is 0.4 mm or more and 10 mm or less.
4.
The metal gasket according to 1, 2 or 3, wherein the radius of curvature of the arcuate portion is 2 mm or more and 20 mm or less.
5.
The length of the hem rising portion is 1/6 or more and 1/3 or less of the total width of the bead portion, and the length of the connecting portion is 1/3 or more and 2 / of the total width of the bead portion. The metal gasket according to any one of 1 to 4, wherein the amount is 3 or less.
6.
The metal gasket according to any one of 1 to 5, wherein the gasket body is coated with an elastic body.

According to the present invention, there is provided a metal gasket which can form a wide contact width with respect to the mating sealing surface, has excellent restoring force characteristics, and can obtain good sealing performance even if cavities are formed on the mating sealing surface. be able to.

An exploded perspective view of a housing to which a metal gasket according to an embodiment of the present invention is applied. Top view showing an example of the metal gasket according to the embodiment of the present invention shown in FIG. Enlarged cross-sectional view along the lines (iii)-(iii) in FIG. (A) is a cross-sectional view showing a state in which the metal gasket shown in FIG. 2 arranged on the sealing surface is uncompressed, and (b) is a state in which the metal gasket shown in FIG. 2 arranged on the sealing surface is compressed. Cross-sectional view shown FEM analysis result of plastic strain of metal gasket shown in FIG. 3 in compressed state A graph comparing the restoring force characteristics of the metal gasket according to the embodiment of the present invention and the full bead gasket and the half bead gasket.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Structure of metal gasket]
FIG. 1 is an exploded perspective view of a housing to which a metal gasket according to an embodiment of the present invention is applied, FIG. 2 is a plan view showing an example of a metal gasket according to an embodiment of the present invention shown in FIG. 1, and FIG. 3 is a plan view. , An enlarged cross-sectional view taken along the line (iii)-(iii) in FIG. 2, FIG. 4 (a) is a cross-sectional view showing an uncompressed state of the metal gasket shown in FIG. 2 arranged on the sealing surface, (b). ) Is a cross-sectional view showing a compressed state of the metal gasket shown in FIG. 2 arranged on the sealing surface.

The housing 100 shown in FIG. 1 is composed of two members, a lid member 101 made of cast parts such as aluminum and a case member 102 also made of cast parts such as aluminum.

The lid member 101 and the case member 102 have sealing surfaces 101a and 102a whose facing surfaces around the openings are made of cast parts, and one sheet is sandwiched between the sealing surfaces 101a and 102a. The metal gasket 1 is arranged. The metal gasket 1 can be preferably applied when the mating sealing surfaces arranged on both sides are both cast parts.

The lid member 101 and the case member 102 are integrally fastened by a bolt 103, whereby the metal gasket 1 is compressed, and the sealing surfaces 101a and 102a are sealed from the sealing fluid.

As shown in FIG. 2, the metal gasket 1 is provided on a gasket body 2 made of a metal substrate such as stainless steel, a cold-rolled steel plate, a galvanized steel plate, or an aluminum plywood, over the entire circumference of the gasket body 2. The side bead portion 3A, the other side bead portion 3B, and an appropriate number of bolt holes 4 through which the bolt 103 is inserted are provided.

The specific structure of the metal gasket 1 will be further described with reference to FIG. FIG. 3 is an enlarged cross-sectional view taken along the line (iii)-(iii) in FIG. 2, and shows the uncompressed metal gasket 1 in which no load is applied.

As shown in FIG. 3, the metal gasket 1 is formed with convex one-sided bead portions 3A and other-sided bead portions 3B on both side surfaces of the gasket body 2. The one-side bead portion 3A is formed so as to be convex toward the sealing surface 101a of the upper lid member 101 in FIG. 1, and the other-side bead portion 3B is the sealing surface of the lower case member 102 in FIG. It is formed so as to be convex toward 102a.

As shown in FIG. 3, the bead portions 3A and 3B have a cross-sectional shape of arcuate portions 31A and 31B, and hem rising portions 32A and 32B of one of the arcuate portions 31A and 31B. It is formed in a shape having a connecting portion 32C for connecting the portions 3A and 3B. The cross-sectional shape of the metal gasket 10 is a rotationally symmetric shape centered on the midpoint of the connecting portion 32C.

The two hem rising portions 32A and 32B are hem rising portions that rise diagonally from the flat portion 21 of the gasket body 2 toward the arcuate portions 31A and 31B via the connecting portion 34, respectively. The bead portions 3A and 3B are connected by a connecting portion 32C arranged between them to form a continuous strip.

The arcuate portions 31A, 31B, the hem rising portions 32A, 32B, and the connecting portion 32C are smoothly connected, but the connecting portion 33A between the arcuate portion 31A of the one-sided bead portion 3A and the hem rising portion 32A. The connecting portion 33B between the arcuate portion 31A and the connecting portion 32C is formed so as to be convex toward the convex side (upper side in FIG. 3) of the one-sided bead portion 3A. Further, the connecting portion 33A between the arcuate portion 31B and the hem rising portion 32B of the other surface side bead portion 3B and the connecting portion 33B between the arcuate portion 31B and the connecting portion 32C are the convex sides of the other surface side bead portion 3B. It is formed so as to be convex toward (lower side in FIG. 3).

That is, the angle θ formed by the arcuate portions 31A and 31B, the hem rising portions 32A and 32B, and the connecting portion 32C on the convex sides of the bead portions 3A and 3B is larger than 180 °. Therefore, the bead portions 3A and 3B are formed so that their inclinations become slightly gentle when they approach the arcuate portions 31A and 31B from the hem rising portions 32A and 32B and the connecting portions 32C.

The hem rising portions 32A and 32B are not limited to those formed as hypotenuse portions having a linear cross-sectional shape, and are curved (arc-shaped) slightly convex on the convex side of the bead portions 3A and 3B. It may be formed as a hypotenuse portion. Further, the connecting portion 32C is not limited to the one formed as a hypotenuse having a linear cross-sectional shape, the side of the bead portion 3A on the one side is slightly convex to the one side, and the side of the bead portion 3B on the other side is the other side. It may be formed in a curved shape slightly convex.

That is, each bead portion 3A and 3B is composed of arcuate portions 31A and 31B, and hem rising portions 32A and 32B having a curvature smaller than those arcuate portions 31A and 31B or having a curvature of 0, and connecting portions 32C. It can also be said that it has been done.

FIG. 4A is a cross-sectional view showing an uncompressed state of the metal gasket shown in FIG. 2 arranged on the sealing surface, and FIG. 4B is a cross-sectional view showing the metal gasket shown in FIG. 2 arranged on the sealing surface. It is sectional drawing which shows the compressed state.

As shown in FIG. 4A, the metal gasket 1 is mounted between the sealing surfaces 101a and 102a. The metal gasket 1 is arranged so that the one-side bead portion 3A is convex toward the sealing surface 101a of the lid member 101, and the other bead portion 3B is convex toward the sealing surface 102a of the case member 102.

Then, when the lid member 101 and the case member 102 are fastened by the bolt 103 with the metal gasket 1 sandwiched between them, as shown in FIG. 4B, the bolt axial force acts on the metal gasket 1 and each bead. Parts 3A and 3B are compressed.

As a result, the arc-shaped portion 31A (the portion between the connection portions 33A and 33B) of the one-side bead portion 3A is pressed against the upper sealing surface 101a, and the arc-shaped portion 31B (each connection portion) of the other-side bead portion 3B is pressed. The portion between 33A and 33B) is pressed against the lower seal surface 102a, and is bent and deformed toward the midpoint position of each of the seal surfaces 101a and 102a. At this time, the connecting portion 32C only changes the inclination angle with respect to the sealing surfaces 101a and 102a at the midpoint position of the sealing surfaces 101a and 102a, and the center position does not change.

Then, each of the arcuate portions 31A and 31B forms a flat surface along the pressed sealing surfaces 101a and 102a. Therefore, the bead portions 3A and 3B form a wide contact width with respect to the sealing surfaces 101a and 102a over the entire width of the arcuate portions 31A and 31B sandwiched between the connection portions 33A and 33B.

[About contact width]
The configuration in which the bead portions 3A and 3B form a wide contact width will be further described.

FIG. 5 shows the FEM analysis result of the plastic strain of the metal gasket 1 according to the present invention in the compressed state.

The plastic strain is color-coded in 21 stages. Hereinafter, in the present specification, the plastic strain is expressed by a numerical value in 21 stages, with the lowest value being "1" and the highest value being "21".

As can be seen from FIG. 5, in the bead portions 3A and 3B of the uncompressed metal gasket 1, the connecting portions 33A and 33B between the arcuate portions 31A and 31B and the hem rising portions 32A and 32B and the connecting portion 32C. In, a higher plastic strain than the arcuate portions 31A and 31B is generated. Further, the connecting portions 34 and 34 between the flat portions 21 and 21 and the hem rising portions 32A and 32B also have higher plastic strain than the arcuate portions 31A and 31B.

That is, in this metal gasket 1, the value of the plastic strain over the entire width of each of the arcuate portions 31A and 31B is lower than the value of the plastic strain at the connection portions 33A, 33B and 34. Specifically, the plastic strains of the connecting portions 33A, 33B, and 34 are "20", and the plastic strains of the arcuate portions 31A, 31B are "5" over the entire width. A high plastic strain indicates that work hardening is in progress, and a larger stress is required to deform it.

From the viewpoint of work hardening due to this plastic deformation, in this metal gasket 1, the arcuate portions 31A and 31B of the bead portions 3A and 3B are more easily deformed than the connection portions 33A, 33B and 34. Therefore, when the bead portions 3A and 3B are compressed, the arcuate portions 31A and 31B and the connection portions 33A, 33B and 34 both begin to deform, but the arcuate portions 31A and 31B and the connection portions 33A, 33B and 34 Due to the difference in work hardening, the amount of deformation is not uniform, and there is a difference between the two.

That is, the connection portions 33A, 33B, and 34, which are more work-hardened, have a smaller amount of deformation than the arc-shaped portions 31A, 31B. Therefore, the amount of deformation of the arcuate portions 31A and 31B sandwiched between the connection portions 33A and 33B in the X direction (width direction) in FIG. 5 is suppressed. As a result, the arcuate portions 31A and 31B are smoothly deformed from the uncompressed arcuate shape to the linear shape shown in FIG. 4B. As a result, the entire arcuate portions 31A and 31B form a flat surface, and excellent contact width characteristics over the entire width are exhibited.

Therefore, as shown in FIG. 4B, concave portions 101b and 102b formed by cavities are formed on the lid member 101 made of cast parts and the sealing surfaces 101a and 102a of the case member 102, which are the bead portions 3A. Even when present on the contact surface with 3B, according to the metal gasket 1 according to the present invention, the arcuate portions 31A and 31B during compression are uniform over a wide contact width with respect to the sealing surfaces 101a and 102a. By forming the surface pressure, the concave portions 101b and 102b can be stably closed, and good sealing properties can be obtained.

Further, since the metal gasket 1 has bead portions 3A and 3B formed on both side surfaces of the gasket body 2, any surface of the gasket body 2 is placed above or below when mounted between the sealing surfaces 101a and 102a. It doesn't matter which direction you choose. Therefore, the mounting workability is also good.

[About surface pressure distribution]
Next, the surface pressure distribution when the arcuate portions 31A and 31B are compressed will be described.

The surface pressure distribution becomes wider as the portion to which the surface pressure is applied during compression becomes wider, and becomes flatter as the contact pressure becomes uniform. The surface pressure distribution of the arcuate portions 31A and 31B in the compressed state of the metal gasket 1 forms a wide contact width in the width direction of the arcuate portions 31A and 31B. That is, each of the arcuate portions 31A and 31B in the metal gasket 1 has a wide surface pressure distribution in the compressed state. This surface pressure distribution does not have a portion protruding in the width direction of the arcuate portions 31A and 31B, and has a substantially flat shape in the width direction of the arcuate portions 31A and 31B. That is, the arcuate portions 31A and 31B form a uniform surface pressure with a wide contact width.

Therefore, as shown in FIG. 4B, even when the concave portions 101b and 102b due to the cavities are present on the contact surfaces of the sealing surfaces 101a and 102a of the lid members 101 and 102, the metal gasket according to the present invention. According to No. 1, since the surface pressure distribution of the arcuate portions 31A and 31B at the time of compression becomes a flat and wide surface pressure distribution in the width direction, the surface pressure is evenly distributed over the entire concave portions 101b and 102b. A stable closed state can be formed.

Therefore, according to the metal gasket 1, by having the plastic strain and the surface pressure distribution, good sealing property can be exhibited without the sealing fluid leaking to the outside through the concave portions 101b and 102b. ..

In order to obtain a good sealing effect due to such plastic strain and surface pressure distribution, the bead portion 3A on one surface side has an arc-shaped portion 31A between the hem rising portion 32A and the connecting portion 32C, and the other surface side. It is important that the bead portion 3B has an arcuate portion 31B between the hem rising portion 32B and the connecting portion 32C.

As shown in FIG. 5, the bead portions 3A and 3B in the present invention are the same when the distance between the connection portions 33A and 33B having high plastic strain (hereinafter, referred to as “width of arcuate portion”) is L1. The larger the width L1 of the arcuate portion in the bead shape (bead width, bead height), the better the contact width characteristics of the arcuate portions 31A and 31B.

The condition for closing and sealing the concave portions 101b and 102b due to the cavities with the arcuate portions 31A and 31B is "contact width> cavities diameter x Fs", and in order to satisfy this condition, the arcuate portions The width L1 can be appropriately set according to the assumed cavity diameter, and is generally set to 0.4 mm or more.

The cavities diameter refers to the maximum cavities diameter in the casting part that is the mating material. Further, Fs is an adjustment parameter related to the sealing pressure, the type and viscosity of the sealing fluid, and the sealing surface roughness.

However, the cavities formed in the cast parts are often 1.5 mm or more. Therefore, specifically, the value of the width L1 of the arcuate portion is preferably 1.5 mm or more from the viewpoint of effectively closing the concave portions 101b and 102b by the cavities.

Further, from the viewpoint of miniaturization and weight reduction of the unit, the sealing surface width of the product using the metal gasket 1 is about 10 mm at the maximum. Therefore, the width L1 of the arcuate portion can be 0.4 mm or more and 10 mm or less. However, considering the sealing surface width of the product, the width L1 of the arcuate portion is preferably about 8 mm or less.

The specific radius of curvature of the arcuate portions 31A and 31B of the bead portions 3A and 3B is preferably 2 mm or more. Since the radius of curvature of each of the arcuate portions 31A and 31B affects the bead width and height, it is difficult to uniformly define them. However, if it is less than 2 mm, the superiority of the contact width characteristic is lowered, and it becomes difficult to effectively close the concave portion due to the cavities. Further, considering the size of the product using the gasket and the contact width characteristics of the bead portions 3A and 3B, the radius of curvature of the arcuate portions 31A and 31B is preferably 20 mm or less.

The length per side (length in the width direction along the slope) of each hem rising portion 32A and 32B of each bead portion 3A and 3B is the total width of each bead portion 3A and 3B (each bead portion 3A and 3B). It is preferably 1/6 or more and 1/3 or less of the width when viewed in a plan view. Further, the length of the connecting portion 32C (the length in the width direction along the slope) is 1/3 or more of the total width of the bead portions 3A and 3B (the width when the bead portions 3A and 3B are viewed in a plan view). It is preferably 2/3 or less.

When the hem rising portions 32A, 32B and the connecting portion 32C are shorter, the deformation of the hem rising portions 32A, 32B and the connecting portion 32C with respect to the deformation of the arc-shaped portions 31A, 31B during compression is suppressed, and the arc-shaped portions 32A and 32C are suppressed. It is possible to develop better contact width characteristics by the parts 31A and 31B. However, when the hem rising portions 32A and 32B are less than 1/6 and the connecting portion 32C is less than 1/3, the reaction force characteristic of the gasket becomes large and the compression characteristic is remarkably deteriorated.

If the hem rising portions 32A and 32B exceed 1/3 and the connecting portion 32C exceeds 2/3, it becomes difficult to set a large curvature of each arc-shaped portion 31A and 31B, and it is difficult to exhibit excellent contact width characteristics. Therefore, it is preferable that the hem rising portions 32A and 32B are 1/3 or less and the connecting portion 32C is 2/3 or less.

[Restoring force characteristics]
FIG. 6 is a graph comparing the restoring force characteristics of the metal gasket according to the embodiment of the present invention and the full bead gasket and the half bead gasket.

Restoring force characteristics were compared between the metal gasket 1 of the present invention and the full bead gasket (convex on one side) and the half bead gasket (convex on one side). As the full bead gasket to be compared, a gasket having a full bead portion having the same shape as one bead portion 3A of the metal gasket 1 of the present invention was used on only one side of the gasket body. As the half bead gasket, a gasket having a half bead portion having a half shape of one bead portion 3A of the metal gasket 1 of the present invention on only one side of the gasket body was used.

Then, the metal gasket 1 was sandwiched between the sealing surfaces 101a and 102a, the lid member 101 and the case member 102 were fastened with bolts 103, and the metal gasket 1 was completely compressed to the material thickness of 0.40 mm. The full bead gasket and the half bead gasket were also fully compressed under the same conditions. Then, while loosening the bolt 103, the linear pressures of the metal gasket 1, the full bead gasket and the half bead gasket were measured. FIG. 6 shows the measurement result.

When the linear pressure became 0 after being released from the fully compressed state, the thickness of the metal gasket 1 of the present invention was restored from 0.40 mm to 0.60 mm or more, 200 μm or more. On the other hand, the thickness of the full bead gasket and the half bead gasket when opened under the same conditions was restored to about 100 μm from 0.40 mm to about 0.50 mm.

As shown in FIG. 6, it was confirmed that the metal gasket 1 of the present invention has better restoring force characteristics than both the full bead gasket and the half bead gasket.

The reason why the metal gasket 1 of the present invention has better restoring force characteristics than the full bead gasket and the half bead gasket is not clear, but it is presumed to be due to the following reasons.

The full bead gasket and the half bead gasket have a bead portion on only one side of the gasket body, and the restoring force direction is only one direction. In these gaskets, a bead portion consisting of a hem rising portion and an arc-shaped portion is formed only on one side of the gasket body, and the restoring force due to the restoration of these to the initial shape acts only on one side of the gasket body. ..

On the other hand, in the metal gasket 1 of the present invention, the bead portions 3A and 3B are provided on both side surfaces of the gasket main body 2, and the restoring force is in two directions. In this metal gasket 1, bead portions 3A and 3B composed of hem rising portions 32A and 32B, connecting portions 32C and arcuate portions 31A and 31B are formed on both side surfaces of the gasket body 2, and these are formed into initial shapes. The restoring force due to the return acts on both sides of the gasket body. Further, in the metal gasket 1 of the present invention, when compressed, forces in opposite directions are applied to one end side of the connecting portion 32C in the upward direction and to the other end side in the downward direction, and the reaction forces of these forces are applied to each other. It becomes a resilience.

That is, in the metal gasket 1 of the present invention, the restoring force of the bead portions 3A and 3B on both sides of the gasket body 2 acts in two directions, and the arcuate portions 31A and 31B are connected by the connecting portion 32C to form a continuous strip. Therefore, it is considered that the restoring force characteristic is excellent due to the synergistic effect of the restoring force acting in opposite directions on one end side and the other end side of the connecting portion 32C.

As described above, the metal gasket 1 of the present invention has excellent restoring force characteristics, that is, due to the large amount of restoration, the sealing pressure is high, and the followability to the mating sealing surface is high, so that the mating sealing surface has a high restoring force. The concave portion can be closed more reliably.

Further, the metal gasket 1 of the present invention can form a wide contact width with respect to the mating sealing surface by having the above-mentioned plastic strain and surface pressure distribution, and has excellent restoring force characteristics, so that the wide contact can be achieved. The width can be maintained, and good sealing performance can be obtained even if cavities are formed on the mating sealing surface.

[Other Embodiments]
The metal gasket 1 of the present invention is not limited to the configuration having two bead portions 3A and 3B as in the above-described embodiment, and is configured by providing three or more bead portions on both side surfaces of the gasket body 2. You may. In this case, the bead portions are connected by a connecting portion, and each bead portion becomes a continuous strip in order such as one side, the other side, and one side, and only the outer parts of the bead parts at both ends rise at the hem. Become a department.

[About rubber coating]
It is preferable that the metal gasket 1 is configured as a so-called rubber-coated metal gasket by coating the gasket body 2 with an elastic body. By providing an elastic body on the surface, even when the mating sealing surface is a rough surface, better sealing performance can be obtained by elastic deformation of the elastic body.

As the elastic body, for example, nitrile rubber, styrene-butadiene rubber, fluororubber, acrylic rubber, silicon rubber and the like can be used. These elastic bodies may be used alone, or may be synthetic rubber (including foam rubber) containing at least one of these rubbers.

When coating such an elastic body, it is preferable to form a base treatment layer on the surface of the gasket body 2 to improve the adhesiveness of the elastic body.

1: Metal gasket 2: Gasket body 21: Flat part 3A, 3B: Bead part 31A, 31B: Arc-shaped part 32A, 32B: Hem rising part 32C: Connecting part 33A, 33B: Connecting part 34: Connecting part 4: Bolt hole 100: Housing 101a, 102a: Sealing surface 101b, 102b: Concave portion

Claims (5)

At least one convex one-sided bead portion is formed on one surface side of the gasket body to form a sealing portion in contact with the mating sealing surface, and at least one to form a sealing portion in contact with the mating sealing surface on the other surface side. Two convex bead portions on the other side are formed,
The one-sided bead portion and the other-side bead portion are metal gaskets that are connected by a connecting portion to form a continuous strip.
The one-sided bead portion is an arc-shaped portion that is convex toward one surface side of the gasket body, and a hem rising portion that rises diagonally from the gasket body toward the arc-shaped portion at one hem portion of the arc-shaped portion. The connection portion between the arcuate portion and the hem rising portion is formed so as to be convex toward the convex side of the one-sided bead portion.
The other-side bead portion has an arc-shaped portion that is convex toward the other surface side of the gasket body and a hem that rises diagonally from the gasket body toward the arc-shaped portion at one hem of the arc-shaped portion. It has a rising portion, and the connecting portion between the arcuate portion and the hem rising portion is formed so as to be convex toward the convex side of the bead portion on the other surface side.
The arcuate portion of the one-sided bead portion and the connecting portion of the connecting portion are formed so as to be convex toward the convex side of the one-sided bead portion, and the arc-shaped portion of the other-side bead portion is formed. A metal gasket characterized in that the connecting portion between the portion and the connecting portion is formed so as to be convex toward the convex side of the other surface side bead portion. Distance between the connecting portion disposed on both sides of the arcuate portion, 0.4 mm or more, the metal gasket according to claim 1, wherein a is 10mm or less. The metal gasket according to claim 1 or 2, wherein the radius of curvature of the arcuate portion is 2 mm or more and 20 mm or less. In the one-sided bead portion, the length of the hem rising portion is 1/6 or more and 1/3 or less of the total width of the one-sided bead portion, and in the other surface side bead portion, the length of the hem rising portion is The length is 1/6 or more and 1/3 or less of the total width of the bead portion on the other side.
The overall widths of the one-sided bead portion and the other-side bead portion are equal to each other, and the length of the connecting portion is 1/3 or more and 2/3 or less of the overall width of the one-sided bead portion. The metal gasket according to any one of claims 1 to 3 . The metal gasket according to any one of claims 1 to 4 , wherein the gasket body is coated with an elastic body.