JP2018031398A - Metal gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal gasket which can form a wide contact width with respect to a mating seal face, is excellent in a restoration force characteristic, and can obtain favorable seal performance even if a blow hole is formed at the mating seal face.SOLUTION: In a metal gasket 1 in which a one-face side bead part 3A and the other face side bead part 3B are formed into a continuous string by being connected to each other by a connecting part 32C, the one-face side bead part 3A has a circular part 31A which is protrusive to one face side, and a skirt erecting part 32A at one skirt part, a connecting region 33A is formed so as to be recessed toward a protrusive side of the one-face side bead part 3A, the other face side bead part 3B has a circular part 31B which is protruded to the other face side, and a skirt erecting part 32B at one skirt part, the connecting region 33A is formed so as to be protrusive toward a protrusive side of the other face side bead part 3B, a connecting region 33B between the circular part 31A and the connecting part 32C is protruded toward a protrusive side of the one-face side bead part 3A, and the connecting region 33B between the circular part 31B and the connecting part 32C is formed so as to be protrusive toward the protrusive side of the other face side bead part 3B.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a metal gasket, and more specifically, a metal that can form a wide contact width with respect to a mating seal surface, has excellent restoring force characteristics, and provides a good sealing property even if a cast hole is generated on the mating seal surface. Related to gaskets.

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

  In cast parts, voids between metal particles may remain inside the part even after sintering and form a cast hole. Since the structure close to the surface of the cast part is dense, the cast hole is not exposed to the outside. However, the surface of the cast part may be finished by cutting after molding in order to increase dimensional accuracy and flatness. At this time, the cast hole inside the cast part may be exposed to the surface by cutting, and a concave portion may be formed by the cast hole.

  If such a concave portion is formed on the mating seal surface of the gasket, there is a problem that sufficient sealing performance by the gasket cannot be obtained. That is, as described above, the gasket is compressed by the bolt axial force between the two members, so that the bead portion is deformed, and at this time, the reaction force generated in the bead portion is brought into close contact with the mating seal surface. 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 a resin or liquid rubber (FIPG) to the mating seal surface to seal the gap with the gasket, or to replace the cast part itself with a structure with less influence of the cast hole. (Patent Document 1). However, with the recent reduction in size and weight of products, the number of products having shapes that are difficult to be molded has increased, and it has become difficult to manage the casting cavity for cast parts. For this reason, a countermeasure against a cast hole has been required for the gasket itself.

  For this reason, various gaskets have been proposed in which measures are taken in cases where the state of the mating seal surface is poor, such as the formation of a concave portion due to a cast hole. For example, by providing an arc-shaped portion that is convex toward the mating seal surface and has a small curvature, a wide contact width is formed on the mating seal surface, and the concave portion formed on the mating seal surface is covered. Gaskets have been proposed (Patent Documents 2 and 3). However, these gaskets are 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, there has been proposed a metal gasket which has a wide contact width by providing a bead in which a plurality of flat bead surfaces are continuously formed through bent portions. (Patent Document 4).

JP 2001-113404 A JP 2011-94667 A JP 2011-117466 A Japanese Patent No. 5450575

  By the way, as a countermeasure for a case where the state of the mating seal surface is bad, such as a concave portion formed by a cast hole, it is preferable not only to widen the contact width but also to have excellent gasket restoring force characteristics.

  If the restoring force characteristic is excellent, the sealing pressure is high, the followability to the mating seal surface is high, and the concave portion of the mating seal 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 seal surface, has excellent restoring force characteristics, and can provide good sealing performance even if a cast hole is generated on the mating seal surface. This is the issue.

  The other subject of this invention becomes clear by the following description.

  The above problems are solved by the following inventions.

1.
At least one convex bead portion is formed on one surface side of the gasket body to be in contact with the mating seal surface to form a seal portion, and on the other surface side is at least one to be in contact with the mating seal surface to form a seal site. The other side bead part which becomes one convex is formed,
The one surface side bead portion and the other surface side bead portion are metal gaskets that are continuous strips by being connected by a connecting portion,
The one-surface-side bead portion includes an arc-shaped portion that protrudes toward one surface of the gasket main body, and a hem rising portion that rises diagonally from the gasket main body toward the arc-shaped portion at one hem portion of the arc-shaped portion. And the connecting portion between the arc-shaped portion and the skirt rising portion is formed to be convex toward the convex side of the one-surface bead portion,
The other surface side bead portion includes an arc-shaped portion that protrudes toward the other surface side of the gasket body, and a hem that rises obliquely from the gasket body toward the arc-shaped portion at one hem portion of the arc-shaped portion. While having a rising part, the connection part of the arcuate part and the skirt rising part is formed to be convex toward the convex side of the other surface side bead part,
The arcuate portion of the one-surface bead portion and the connecting portion of the connecting portion are formed so as to protrude toward the convex side of the one-surface bead portion, and the arc-shape of the other-surface bead portion. The metal gasket is 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.
The plastic strain over the entire width of each arcuate part is lower than that of each connection site, and the surface pressure distribution of each arcuate part in the compressed state is flat and wide across the width direction of each arcuate part. 2. The metal gasket according to 1 above, wherein
3.
3. The metal gasket according to 1 or 2, wherein an interval between the connection parts arranged on both sides of the arcuate part is 0.4 mm or more and 10 mm or less.
4).
4. The metal gasket according to 1, 2, or 3, wherein a radius of curvature of the arc-shaped portion is 2 mm or more and 20 mm or less.
5).
The length of the skirt rising portion is 1/6 or more and 1/3 or less of the entire width of the bead portion, and the length of the connecting portion is 1/3 or more of the entire width of the bead portion. The metal gasket according to any one of 1 to 4, wherein the metal gasket is 3 or less.
6).
6. The metal gasket according to any one of 1 to 5, wherein the gasket body is covered with an elastic body.

  ADVANTAGE OF THE INVENTION According to this invention, while providing a wide contact width with respect to the other party seal surface, the metal gasket which is excellent in a restoring force characteristic and can obtain favorable sealing performance even if the casting hole has generate | occur | produced in the other party seal surface is provided. be able to.

The disassembled perspective view of the housing | casing to which the metal gasket which concerns on embodiment of this invention is applied. The top view which shows an example of the metal gasket which concerns on embodiment of this invention shown in FIG. Enlarged cross-sectional view along line (iii)-(iii) in FIG. 2A is a cross-sectional view showing an uncompressed state of the metal gasket shown in FIG. 2 arranged on the seal surface, and FIG. 2B shows a state where the metal gasket shown in FIG. 2 arranged on the seal surface is compressed. Cross section shown FEM analysis result of plastic strain of metal gasket shown in Fig. 3 in compressed state The graph which compares a restoring force characteristic with the metal gasket which concerns on embodiment of this invention, and a full bead gasket and a half bead gasket

  Embodiments of the present invention will be described below with reference to the drawings.

[Composition of metal gasket]
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 the embodiment of the present invention shown in FIG. 1, and FIG. FIG. 4 is an enlarged cross-sectional view taken along line (iii)-(iii) in FIG. 2, FIG. 4A is a cross-sectional view showing a state in which the metal gasket shown in FIG. ) Is a cross-sectional view showing a state in which the metal gasket shown in FIG. 2 arranged on the seal surface is compressed.

  A housing 100 shown in FIG. 1 includes two members, a lid member 101 made of a cast part such as aluminum and a case member 102 made of a cast part such as aluminum.

  The cover member 101 and the case member 102 have seal surfaces 101a and 102a made of cast parts at the opposing surfaces around the respective openings, and one sheet so as to be sandwiched between the seal surfaces 101a and 102a. A metal gasket 1 is arranged. This metal gasket 1 can be preferably applied when both mating seal surfaces arranged on both sides are 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 space between the sealing surfaces 101a and 102a is 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, cold-rolled steel sheet, galvanized steel sheet, aluminum plywood, etc., over the entire circumference of the gasket body 2. The side bead portion 3A and the other surface side bead portion 3B and an appropriate number of bolt holes 4 through which the bolts 103 are inserted are provided.

  A 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 line (iii)-(iii) in FIG. 2, and shows the uncompressed metal gasket 1 that is not loaded.

  As shown in FIG. 3, the metal gasket 1 is formed with a bead portion 3 </ b> A on one side and a bead portion 3 </ b> B on the other surface that are convex on both side surfaces of the gasket body 2. The one surface side bead portion 3A is formed so as to protrude toward the seal surface 101a of the upper lid member 101 in FIG. 1, and the other surface side bead portion 3B is the seal surface of the lower case member 102 in FIG. It is formed to be convex toward 102a.

  As shown in FIG. 3, each bead portion 3A, 3B has an arc-shaped portion 31A, 31B and a skirt rising portion 32A, 32B at one hem portion of each arc-shaped portion 31A, 31B, and each bead. It is formed in a shape having a connecting part 32C for connecting the parts 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 skirt rising portions 32A and 32B are skirt rising portions that rise obliquely from the flat portion 21 of the gasket body 2 through the connection portion 34 toward the arc-shaped portions 31A and 31B. And each bead part 3A, 3B is connected by the connection part 32C arrange | positioned between both, and becomes a continuous strip.

  Each arcuate portion 31A, 31B, each skirt rising portion 32A, 32B, and connecting portion 32C are connected smoothly, but a connecting portion 33A between the arcuate portion 31A of one surface side bead portion 3A and the skirt rising portion 32A. And the connection part 33B of 31 A of circular-arc-shaped parts and the connection part 32C is formed so that it may become convex toward the convex side (upper side in FIG. 3) of 3 A of bead parts. Further, the connecting portion 33A between the arc-shaped portion 31B and the skirt rising portion 32B of the other surface side bead portion 3B and the connecting portion 33B between the arc-shaped portion 31B and the connecting portion 32C are the convex side of the other surface side bead portion 3B. It is formed to be convex toward (lower side in FIG. 3).

  That is, on the convex side of each bead part 3A, 3B, the angle θ formed by each arcuate part 31A, 31B, the skirt rising part 32A, 32B, and the connecting part 32C is larger than 180 °. For this reason, each bead part 3A, 3B is formed so that each inclination may become slightly gentle when approaching each arcuate part 31A, 31B from each skirt rising part 32A, 32B and connection part 32C.

  The skirt rising portions 32A and 32B are not limited to those having a cross-sectional shape formed as a straight oblique side, but are curved (arc-shaped) slightly convex on the convex sides of the bead portions 3A and 3B. It may be formed as a hypotenuse. Further, the connecting portion 32C is not limited to one having a cross-sectional shape that is formed as a straight hypotenuse, the one-surface-side bead portion 3A side is slightly convex toward the one-surface side, and the other-surface-side bead portion 3B side is the other-surface side. Alternatively, it may be formed in a slightly convex curved shape.

  That is, each bead part 3A, 3B is comprised by each arc-shaped part 31A, 31B and each skirt rising part 32A, 32B and the connection part 32C whose curvature is smaller than these arc-shaped parts 31A, 31B or 0 curvature. It can also be said that.

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

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

  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. 4 (b), a bolt axial force acts on the metal gasket 1, and each bead The 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-surface-side bead portion 3A is pressed against the upper seal surface 101a, and the arc-shaped portion 31B (each connection portion of the other-surface-side bead portion 3B). The portion between 33A and 33B) is pressed by 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 seal surfaces 101a and 102a at the midpoint positions of the seal surfaces 101a and 102a, and the center position does not change.

  Each arcuate portion 31A, 31B forms a flat surface along the pressed seal surfaces 101a, 102a. Therefore, each bead part 3A, 3B forms the wide contact width over the full width of each arcuate part 31A, 31B pinched | interposed into each connection site | part 33A, 33B with respect to each seal surface 101a, 102a.

[Contact width]
The configuration in which each bead portion 3A, 3B forms a wide contact width will be further described.

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

  The plastic strain is color-coded and displayed in 21 levels. However, in the present specification, the plastic strain is expressed by numerical values in 21 levels, 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 connection portions 33A and 33B of the arc-shaped portions 31A and 31B and the skirt rising portions 32A and 32B and the connecting portion 32C are connected. , Higher plastic strain than the arc-shaped portions 31A and 31B occurs. Further, also in the connection portions 34 and 34 between the flat portions 21 and 21 and the skirt rising portions 32A and 32B, higher plastic strain is generated than in the arc-shaped portions 31A and 31B.

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

  From the viewpoint of work hardening due to this plastic deformation, in the metal gasket 1, the arc-shaped portions 31A, 31B of the bead portions 3A, 3B are more easily deformed than the connection portions 33A, 33B, 34. Therefore, when each bead part 3A, 3B is compressed, the arc-shaped parts 31A, 31B and the connection parts 33A, 33B, 34 both start to deform, but the arc-shaped parts 31A, 31B and the connection parts 33A, 33B, 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 where work hardening is progressing have a smaller amount of deformation than the arc-shaped portions 31A and 31B. Therefore, the amount of deformation in the X direction (width direction) in FIG. 5 is suppressed in each of the arcuate portions 31A and 31B sandwiched between the connection portions 33A and 33B. Thereby, each circular arc-shaped part 31A, 31B deform | transforms smoothly from the uncompressed circular arc shape to the linear shape shown in FIG.4 (b). Thereby, the whole arc-shaped part 31A, 31B forms a flat surface, and the outstanding contact width characteristic over the full width is expressed.

  Accordingly, as shown in FIG. 4B, concave portions 101b and 102b are formed on the sealing member 101 made of cast parts and the sealing surfaces 101a and 102a of the case member 102 by the cast holes, and these are the bead portions 3A, Even when it exists on the contact surface with 3B, according to the metal gasket 1 according to the present invention, the arc-shaped portions 31A and 31B at the time of compression are evenly distributed over a wide contact width with respect to the seal surfaces 101a and 102a. By forming the surface pressure, it is possible to stably close the concave portions 101b and 102b and obtain a good sealing property.

  Further, since the metal gasket 1 has bead portions 3A and 3B formed on both side surfaces of the gasket body 2, respectively, any surface of the gasket body 2 is faced up or down when being mounted between the seal surfaces 101a and 102a. Anyway, it doesn't matter the direction. Therefore, the mounting workability is also good.

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

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

  Therefore, as shown in FIG. 4 (b), the metal gasket according to the present invention is provided even when the concave portions 101b and 102b are formed on the contact surfaces of the sealing surfaces 101a and 102a of the lid members 101 and 102. 1, since the surface pressure distribution of the arc-shaped portions 31A and 31B during compression becomes a flat and wide surface pressure distribution in the width direction, the surface pressure distribution is uniform over the entire concave portions 101b and 102b. A stable closed state can be formed.

  Therefore, according to this metal gasket 1, by having the plastic strain and the surface pressure distribution, it is possible to exhibit a good sealing performance without leaking the sealing fluid 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 one-surface-side bead portion 3A has an arc-shaped portion 31A between the skirt rising portion 32A and the connecting portion 32C, and the other surface side It is important that the bead part 3B has an arcuate part 31B between the skirt rising part 32B and the connecting part 32C.

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

  A condition for sealing the concave portions 101b and 102b by the cast hole by sealing with the arc-shaped portions 31A and 31B is “contact width> cast hole diameter × Fs”. In order to satisfy this condition, the arc-shaped portion The width L1 can be appropriately set in accordance with the assumed cavity diameter, and is generally set to 0.4 mm or more.

  In addition, a cast hole diameter refers to the maximum cast hole diameter in the casting component used as a counterpart material. 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 cast hole diameter generated in the cast part is often 1.5 mm or more. Therefore, specifically, the value of the width L1 of the arc-shaped portion is preferably set to 1.5 mm or more from the viewpoint of effectively closing the concave portions 101b and 102b due to the cast hole.

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

  It is preferable that the specific curvature radius of each arc-shaped part 31A, 31B of each bead part 3A, 3B is 2 mm or more. Since the radius of curvature of each arcuate portion 31A, 31B affects the bead width and height, it is difficult to uniformly define it. However, when the thickness is less than 2 mm, the superiority of the contact width characteristic is lowered, and it is difficult to effectively close the concave portion due to the cast hole. Further, considering the size of the product using the gasket and the contact width characteristics of each bead portion 3A, 3B, the radius of curvature of each arcuate portion 31A, 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, 32B of each bead portion 3A, 3B is the total width (each bead portion 3A, 3B) of each bead portion 3A, 3B. It is preferable that the width is 1/6 or more and 1/3 or less of the width in a plan view. Further, the length of the connecting portion 32C (the length in the width direction along the inclined surface) is 1/3 or more of the overall width of each bead portion 3A, 3B (the width when the bead portions 3A, 3B are viewed in plan). 2/3 or less is preferable.

  The shorter the skirt rising portions 32A, 32B and the connecting portions 32C, the deformation of the skirt rising portions 32A, 32B and the connecting portions 32C with respect to the deformation of the arc-shaped portions 31A, 31B at the time of compression is suppressed. The contact width characteristics can be more excellently expressed by the portions 31A and 31B. However, when each of the skirt rising portions 32A and 32B is less than 1/6 and the connecting portion 32C is less than 1/3, the reaction force characteristic of the gasket is increased, and the compression characteristic is remarkably deteriorated.

  When the skirt rising portions 32A and 32B exceed 1/3 and the connecting portion 32C exceeds 2/3, it is difficult to set a large curvature of each arcuate portion 31A and 31B, and excellent contact width characteristics are hardly exhibited. Therefore, it is preferable that the skirt 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 restoring force characteristics of a metal gasket according to an embodiment of the present invention, a full bead gasket, and a half bead gasket.

  Restoring force characteristics were compared between the metal gasket 1 of the present invention, a full bead gasket (one side convex) and a half bead gasket (one side convex). As a full bead gasket to be compared, one having a full bead portion having the same shape as one bead portion 3A of the metal gasket 1 of the present invention only on one side of the gasket main body was used. As the half bead gasket, one having a half bead portion of a half shape of one bead portion 3A of the metal gasket 1 of the present invention only on one side of the gasket main 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 by the bolt 103, and the metal gasket 1 was fully compressed to 0.40 mm thickness which is the material thickness. The full bead gasket and the half bead gasket were also fully compressed under the same conditions. Then, the linear pressure of the metal gasket 1, full bead gasket, and half bead gasket was measured while loosening the bolt 103. FIG. 6 shows the measurement results.

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

  As shown in FIG. 6, it was confirmed that the metal gasket 1 of the present invention has a restoring force characteristic superior to both the full bead gasket and the half bead gasket.

  The reason why the metal gasket 1 of the present invention has a restoring force characteristic superior to that of the full bead gasket and the half bead gasket is not clear, but is presumed to be as follows.

  The full bead gasket and the half bead gasket have a bead portion only on one side of the gasket body, and the restoring force is only in one direction. In these gaskets, a bead portion consisting of a skirt rising portion and an arc-shaped portion is formed only on one side of the gasket body, and the restoring force due to returning 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 sides of the gasket body 2, and the restoring force is in two directions. In this metal gasket 1, bead portions 3A and 3B including skirt rising portions 32A and 32B, a connecting portion 32C, and arc-shaped portions 31A and 31B are formed on both sides of the gasket main body 2, respectively. 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 in the upward direction are applied to one end side and the other end side of the coupling portion 32C, and the reaction forces of these forces are respectively applied. It becomes a restoring force.

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

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

  In addition, the metal gasket 1 of the present invention has the above-mentioned plastic strain and surface pressure distribution, so that a wide contact width can be formed with respect to the mating seal surface, and the excellent contact force characteristic makes the wide contact. The width can be maintained, and a good sealing property can be obtained even if a cast hole is generated on the mating seal surface.

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

[About rubber coating]
The metal gasket 1 is preferably configured as a so-called rubber-coated metal gasket by covering the gasket body 2 with an elastic body. By providing an elastic body on the surface, even if the mating seal 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, fluorine rubber, acrylic rubber, silicon rubber or the like can be used. These elastic bodies may be used alone or may be synthetic rubber (including foamed rubber) containing at least one of these rubbers.

  When covering such an elastic body, it is preferable to form a base treatment layer on the surface of the gasket body 2 for improving the adhesion of the elastic body.

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

Claims (6)

At least one convex bead portion is formed on one surface side of the gasket body to be in contact with the mating seal surface to form a seal portion, and on the other surface side is at least one to be in contact with the mating seal surface to form a seal site. The other side bead part which becomes one convex is formed,
The one surface side bead portion and the other surface side bead portion are metal gaskets that are continuous strips by being connected by a connecting portion,
The one-surface-side bead portion includes an arc-shaped portion that protrudes toward one surface of the gasket main body, and a hem rising portion that rises diagonally from the gasket main body toward the arc-shaped portion at one hem portion of the arc-shaped portion. And the connecting portion between the arc-shaped portion and the skirt rising portion is formed to be convex toward the convex side of the one-surface bead portion,
The other surface side bead portion includes an arc-shaped portion that protrudes toward the other surface side of the gasket body, and a hem that rises obliquely from the gasket body toward the arc-shaped portion at one hem portion of the arc-shaped portion. While having a rising part, the connection part of the arcuate part and the skirt rising part is formed to be convex toward the convex side of the other surface side bead part,
The arcuate portion of the one-surface bead portion and the connecting portion of the connecting portion are formed so as to protrude toward the convex side of the one-surface bead portion, and the arc-shape of the other-surface bead portion. The metal gasket is 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.   The plastic strain over the entire width of each arcuate part is lower than that of each connection site, and the surface pressure distribution of each arcuate part in the compressed state is flat and wide across the width direction of each arcuate part. The metal gasket according to claim 1, wherein   The metal gasket according to claim 1 or 2, wherein an interval between the connection parts arranged on both sides of the arcuate part is 0.4 mm or more and 10 mm or less.   4. The metal gasket according to claim 1, wherein the radius of curvature of the arc-shaped portion is 2 mm or more and 20 mm or less.   The length of the skirt rising portion is 1/6 or more and 1/3 or less of the entire width of the bead portion, and the length of the connecting portion is 1/3 or more of the entire width of the bead portion. It is 3 or less, The metal gasket in any one of Claims 1-4 characterized by the above-mentioned.   The metal gasket according to claim 1, wherein the gasket body is covered with an elastic body.