JPH11159622A - Metal-made gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal-made gasket relaxing deformation of a bead, preventing full compression, equalizing a surface pressure of a bead total unit, and attaining improvement to durability and seal performance of the bead. SOLUTION: In a metal-made gasket 1, since a sub-plate 4 interposing a buffer material 11 between an intermediate plate 9 and a thin metal plate 10 is interposed by a pair of bead plates 2, 3 to be layered, when the metal-made gasket 1 is interposed between opposed mounting surfaces and tightened by a bolt or the like, a bead 7 is pressed by the sub-plate 4 and deformed. By elastic action of the buffer material 11, a surface pressure and stress of the bead plate 2, 3 concentrated in a top part 8 of the bead 7 are reduced, deformation of the bead of the bead plates 2, 3 is relaxed, and durability and seal performance of the bead are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal gasket used for sealing between opposed mounting surfaces of a structural component, particularly between opposed mounting surfaces of a cylinder block and a cylinder head in a multi-cylinder engine. .

[0002]

2. Description of the Related Art Recent engines are required to have higher output and lighter weight. As a part of such demands, there is a tendency that cylinder heads and cylinder blocks constituting a multi-cylinder engine are manufactured from aluminum material. Aluminum cylinder heads and cylinder blocks are lighter than iron-based materials, but tend to increase relative displacement between the cylinder head and cylinder blocks during engine operation. For this reason, metal gaskets used to seal between the opposing mounting surfaces are generally
It is made of an elastic metal plate having a bead formed on the periphery such as a bore hole. Here, the bore hole refers to a hole formed in the elastic metal plate so as to correspond to the cylinder bore formed in the cylinder block. In addition to the bore holes, various holes such as bolt holes, knock holes, water holes, oil holes, and the like are formed in the elastic metal plate, and beads are also formed on the periphery of these holes.

[0003] Various types of metal gaskets have been developed in the past, but one of them is to laminate an intermediate plate between a pair of bead plates having beads formed on the peripheral edge of a bore hole. There are metal gaskets. Such a metal gasket is formed by forming a thick metal plate surrounding the periphery of the bore hole with a band of an appropriate width into a predetermined shape, forming the remaining portion of the gasket with a thin metal plate, and forming both of these metal plates. To form a sub-plate, while forming an elastic metal plate into a predetermined shape of a gasket and forming a bead around the periphery of a bore hole of the elastic metal plate to produce two bead plates. The top of the bead is brought into contact with the thick metal plate
The sub-plate is laminated with two bead plates sandwiched from both sides (for example, see Japanese Utility Model Application Laid-Open No. 4-71865).

In the metal gasket disclosed in Japanese Patent Application Laid-Open No. 7-243531, a metal plate for a peripheral portion of a bore hole surrounding a peripheral portion of the bore hole with a band of an appropriate width is formed in a predetermined shape. A metal intermediate plate formed in the predetermined shape of the gasket is superimposed with a metal plate for the periphery of the bore hole, and the superposed part is laser welded to integrate the two metal plates to produce a sub-plate. The plate is formed into a predetermined shape of the gasket, and a bead is formed at the periphery of the bore hole of the elastic metal plate to produce two bead plates, and the top of the bead is brought into contact with the overlapping portion of the sub-plate. The sub-plate is superposed from both sides by two bead plates.

[0005]

However, in each of the above-mentioned conventional metal gaskets, the top of the bead is in contact with the thick portion of the auxiliary plate (the portion of the thick metal plate or the overlapped portion). Moreover, since there is no stopper for limiting the amount of deformation of the bead, if the metal gasket is clamped between the mounting surfaces of the cylinder head and cylinder block facing each other and tightened with bolts, the top of the bead and the bead will be completely When fully compressed to the flexed state, that is, when fully compressed, a large surface pressure (peak value) is generated in the bead, a large bead deformation occurs, and an early sag of the bead, that is, a permanent deformation of the spring occurs, Decreases durability of sealing performance.

During engine operation, the stress in the boundary region between the cylinder head and the cylinder block repeatedly increases and decreases, and the metal gasket is subjected to repeated stress, that is, mechanical stress and thermal stress. These load fluctuation stresses occur as large values in the least rigid part of the cylinder block or cylinder head, resulting in a problem that the bead is set or cracks occur and the sealing performance is deteriorated. .

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to form a bead on a pair of elastic metal plates so as to have an elastic action, and to laminate them so as to increase the elastic action as a whole. In addition to preventing deformation by alleviating deformation, the peak pressure of the bead is reduced and the overall surface pressure of the bead is averaged to form a sealing surface in surface contact, improving the durability and sealing performance of the bead. It is to provide a metal gasket that can be secured.

According to the present invention, there is provided a pair of elastic metal plates in which a bead is formed around a bore hole and the tops of the beads are arranged so as to face each other, and an intermediate metal plate arranged between the pair of elastic metal plates. The present invention relates to a metal gasket comprising a metal gasket, wherein a thin metal plate which is in contact with the bead via a buffer material is laminated on a surface of the intermediate plate. Here, the intermediate plate is a metal plate disposed between a pair of elastic metal plates and having the same or substantially the same contour as the contour of the elastic metal plate. The thin metal plate is a plate thinner than the intermediate plate.

In this metal gasket, a cushioning material is interposed between an intermediate plate and a thin metal plate, and this is sandwiched between a pair of elastic metal plates having beads. The bead is compressed and deformed when placed between the opposed mounting surfaces of the head and the cylinder block and tightened with bolts or the like. At this time, the metal gasket reduces the surface pressure concentrated on the top of the bead and the stress of the elastic metal plate by the elastic action of the cushioning material, the surface pressure of the entire bead is averaged, and the deformation of the bead is reduced. Therefore, the durability and sealing performance of the bead are improved.

The metal gasket follows the movement of the cylinder head during engine operation by the elastic action of the elastic metal plate and the elastic action of the cushioning material interposed between the intermediate plate and the thin metal plate. It is possible to maintain stable sealing performance over a long period of time. Furthermore,
Since a buffer material was interposed between the intermediate plate and the thin metal plate,
The combustion gas does not leak from between the intermediate plate and the thin metal plate, and the sealing performance is improved.

The cushioning material is preferably a non-metallic material such as a heat-resistant rubber or a heat-resistant resin, and the heat-resistant rubber or the heat-resistant resin has a shape substantially the same as that of a thin metal plate. The heat-resistant rubber or heat-resistant resin may be placed on the entire surface including the top of the bead between the intermediate plate and the thin metal plate, or the heat-resistant rubber or the heat-resistant resin may be thin except for the top position of the bead. You may make it arrange | position between metal plates.
When the bead is located except for the top position, a small space is formed between the intermediate plate and the thin metal plate at the top position of the bead, and a step is formed there, and the deformation of the bead is reduced. Will not be compressed. That is, a gap corresponding to the thickness of the cushioning material is formed in a region where the cushioning material corresponds to the top of the bead before use, and the step of the gap reduces the compression of the bead, and the surface pressure in the region of the top of the bead is reduced. Concentration is eased. When the above space is formed, the deformation of the bead is reduced as compared with the case where the space is not formed,
The surface pressure of the entire bead is averaged, and the durability and sealing performance of the bead can be further improved. In addition, since the heat-resistant rubber or heat-resistant resin disposed on both sides of the space functions as a stopper, the amount of deformation of the bead is suppressed, and excessive deformation of the bead, that is, full compression of the bead is prevented.

It is important that the metal gasket has a structure in which a heat-resistant rubber or a heat-resistant resin is interposed between the intermediate plate and the thin metal plate, and the interposing method may be appropriately selected. However, it is particularly preferable to fix to the intermediate plate. At the time of fixing, since a very thin heat-resistant rubber or heat-resistant resin is used, it is preferable from the viewpoint of manufacture that it be printed on an intermediate plate. Further, it is preferable that the intermediate plate and the thin metal plate are integrated by welding.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a metal gasket according to the present invention will be described below with reference to FIGS.
FIG. 1 is a partial plan view showing one embodiment of a metal gasket according to the present invention, and FIG. 2 is a sectional view of the metal gasket shown in FIG.
3 is a plan view showing an intermediate plate on the surface of which a heat-resistant rubber used for the metal gasket of FIG. 1 is printed, and FIG. 4 is a B-B of the intermediate plate with the heat-resistant rubber of FIG.
FIG. 5 is a cross-sectional view of the intermediate plate with the heat-resistant rubber of FIG.

The metal gasket 1 shown in FIG. 1 is used to seal a space between opposed mounting surfaces of a cylinder head and a cylinder block in a multi-cylinder engine. As can be seen from the cross-sectional view shown in FIG. 2, the metal gasket 1 is a laminated gasket composed of a pair of bead plates 2 and 3 made of an elastic metal plate and a sub plate 4 sandwiched between the two bead plates 2 and 3. Body. The bead plates 2 and 3 are formed, for example, by punching a stainless steel spring plate (SUS301, 3 / 4H, H), performing a forming process such as a bead process, and performing a heat treatment and a surface treatment to obtain a predetermined tensile strength, elongation and hardness. It has something. Bore holes 5 are formed in the bead plates 2 and 3 in parallel corresponding to the number and positions of the cylinder bores formed in the cylinder block. Bore holes 5 formed in the bead plates 2 and 3 are bordered by bore hole edges 6 and formed at the same position and the same size.

A bead 7 is provided on the bead plates 2 and 3.
As shown by a dashed line in FIG. 1, each of the bores 5 is formed in an annular shape along the periphery of the hole edge 6. Bead 7
As shown in FIG. 2, the tops 8 of the beads 7 are formed so as to face each other. The height and width of the bead 7 can be changed according to the circumferential position even around the same bore hole 5. For example, in a small engine, the region between the adjacent bore holes 5 is very narrow, so that the width of the two beads 7 is set to be narrower than the width of the beads in other regions. As the distance from the region between the adjacent bore holes 5 increases, the width of the bead can be gradually increased. Also, the bead height can be changed in the area between the adjacent bore holes 5 such that the bead height is higher than the other areas in order to obtain a high sealing force. FIG.
In the state where the bead plates 2, 3 and the sub-plate 4 are overlapped, the same cross-sectional structure is formed between the other adjacent bore holes 5.

As shown in the sectional view of FIG. 2, the sub-plate 4 has a laminated structure in which a heat-resistant rubber 11 as a cushioning material is disposed between the intermediate plate 9 and the thin metal plate 10. It is. The intermediate plate 9 is formed by forming a plate of stainless steel (SUS430) into almost the same shape as the bead plates 2 and 3. That is, bore holes are formed in the intermediate plate 9 and the thin metal plate 10 in parallel according to the number and positions of the cylinder bores formed in the cylinder block. Bore hole 12 of intermediate plate 9
Are formed at the same position and the same size as the bore holes 5 of the bead plates 2 and 3.

The surface of the intermediate plate 9 is coated with a fluoro rubber 11 which is a heat resistant rubber by printing in a region shown by hatching in FIG. That is, the fluoro rubber 11 is coated by printing so as to surround the periphery of the bore hole 12 of the intermediate plate 9 with a region of an appropriate width.

Alternatively, as another embodiment, a fluororubber 11
4 and 5, as shown in FIG. 4 and FIG.
Coating is performed on one surface of the intermediate plate 9 except for an area that is not printed slightly inside the area 3 (the area 14 that is not coated = 0.5 mm). The uncoated area 14 is provided in consideration of the positional deviation at the time of producing the print, and is provided on the intermediate plate 9 in order to prevent the fluoro rubber 11 from being coated on the bore edge 13. is there.

The thin metal plate 10 is formed of a plate of stainless steel (SUS430, SUS304) thinner than the intermediate plate 9 and has bore holes corresponding to the bore holes 5 of the bead plates 2 and 3, and FIG. As shown by the broken line in the outline, bead plate 2,
3 is formed so as to surround the periphery of the bore hole 5 with a band having an appropriate width. The thin metal plate 10 is put on the intermediate plate 9 coated with the fluoro rubber 11 and fixed to the intermediate plate 9 by spot welding at a position 15 shown in FIG. Thus, the sub-plate 4 is manufactured by spot welding the thin metal plate 10 to the intermediate plate 9 coated with the fluoro rubber 11.

When the metal gasket 1 is sandwiched between the opposed mounting surfaces of the cylinder head and the cylinder block and fastened with bolts or the like, the beads 7 of the bead plates 2 and 3 are closed.
7 are deformed in contact with each other. Around the bore holes 5 of the bead plates 2 and 3 where high sealing performance is required, the surface pressure of the beads 7 and 7 is sufficient due to the reaction when the beads 7 and 7 are crushed and deformed between the opposed mounting surfaces. An elastic annular contact portion is formed which is higher than that of the other, and the annular contact portion provides a sealing function for preventing fluid such as combustion gas passing through the bore hole 5 of the bead plates 2 and 3 from leaking from between the opposed mounting surfaces. Can be Also, the beads 7, 7 of the bead plates 2, 3 are:
Since the inner and outer skirt positions are in strong contact with the opposing mounting surface to form a sealing portion in a surface contact state, it is possible to ensure sealing performance between the adjacent bore holes 5 where high-temperature combustion gas easily leaks. Since the degree of leakage of the combustion gas is lower around the bore holes except between the adjacent bore holes 5 than between the adjacent bore holes 5, a single bead composed of the beads 7 is formed.

In the metal gasket 1, since the intermediate plate 9 is coated with the fluoro rubber 11, the seal between the intermediate plate 9 and the thin metal plate 10 is ensured. That is, the fluoro rubber 11 functions as a sealing member between the intermediate plate 9 and the thin metal plate 10. In addition, when the bead 7 is pressed against the sub-plate 4 with a strong force, the fluoro rubber 11 acts as a buffer, and as a result, the deformation of the bead 7 of the bead plates 2 and 3 is reduced, The entire compression of the bead 7 is prevented, and the surface pressure of the entire bead 7 is averaged. Therefore, the sealing performance can be improved, and the bore distortion that is likely to occur between adjacent cylinder bores can be reduced.

The metal gasket 1 has an elastic effect of the fluoro rubber 11 interposed between the intermediate plate 9 and the thin metal plate 10 in addition to the elastic effect of the bead 7, so that the metal gasket 1 Since it is easy to follow a change in the gap with the cylinder block, the metal gasket 1 can maintain stable sealing performance for a long period of time. In addition, the metal gasket 1 is
A sub-plate 4 having a fluoro rubber 11 interposed between it and a thin metal plate 10 is laminated with a pair of bead plates 2 and 3 interposed therebetween. Pressure and bead plate 2, concentrated on top 8 of
Since the stress of No. 3 can be relieved, the durability of the bead is also improved.

The specific dimensions and the like of the metal gasket in this embodiment will be described below. Bead plate: 0.20-0.30mm (thickness), SUS3
01 3 / 4H, H Intermediate plate: 0.12-0.15mm (thickness), SUS
430 Thin metal plate: 0.08-0.10mm (thickness), SUS
430, SUS304 Heat-resistant rubber, heat-resistant resin: 0.02 to 0.03 mm (thickness), about 5 mm (width)

Next, another embodiment of the metal gasket according to the present invention will be described with reference to FIGS.
6 is a cross-sectional view taken along line AA of the metal gasket shown in FIG. 1, and FIG. 7 is a view B of the intermediate plate with heat-resistant rubber shown in FIG. -B
8 is a sectional view taken along line CC of the intermediate plate with heat resistant rubber shown in FIG. 3.

As can be seen from the sectional view shown in FIG. 6, the metal gasket 16 of this embodiment has a pair of bead plates 17 and 18 made of an elastic metal plate and a sub-bead sandwiched between the two bead plates 17 and 18. It is a laminate composed of a plate 19. The bead plates 17 and 18 are made of, for example, stainless spring steel (SUS3).
01, 3 / 4H, H) is punched out, subjected to forming processing such as beading, heat-treated and surface-treated, and has predetermined tensile strength, elongation, and hardness. Since it is the same as the bead plates 2 and 3 shown in FIG. 2, the description is omitted.

The sub-plate 19 has a laminated structure in which a heat-resistant rubber 22 as a buffer material is disposed between an intermediate plate 20 and a thin metal plate 21, as shown in a sectional view of FIG. It is. The structure and material of the intermediate plate 20 and the thin metal plate 21 are as follows.
Since they are the same as those in FIG. 2, the description about them is omitted.

On the surface of the intermediate plate 20, a fluoro rubber 22, which is a heat-resistant rubber, is applied by printing in a hatched area in FIG. That is, the fluoro rubber 22 is applied by printing so as to surround the peripheral portion of the bore hole 12 of the intermediate plate 20 with a region of an appropriate width. However, FIG.
As shown in FIG. 8, one surface of the intermediate plate 20 is coated except for a region 14 (non-coated region: 0.5 mm) that is not printed slightly inside the bore hole edge 13 of the intermediate plate 20. Uncoated area 14
Is provided in consideration of the positional deviation at the time of print production, and is provided to prevent the fluoro rubber 22 from adhering to the bore hole edge 13. A major feature of this embodiment is that, as can be seen from FIG.
4 is that there is an area where the fluorocarbon rubber 22 is not coated on the intermediate plate 20 (an area 23 that is not coated). Uncoated area 2
Reference numeral 3 denotes an annular shape having a width of 1.0 mm along the shape of the bead 7.

The sub-plate 19 is manufactured by covering a thin metal plate 21 from above the intermediate plate 20 coated with fluororubber 22 and fixing it to the intermediate plate 20 by spot welding at a position 15 shown in FIG. The sub-plate 19 manufactured in this way is shown in FIG.
As shown in FIG. 2, since the area 23 where the fluoro rubber 22 is not coated exists, the intermediate plate 20 and the thin metal plate 2
1 has a structure in which a small space 25 is formed. The sub-plate 19 is located between the two bead plates 17 and 18.
The metal gasket 16 manufactured with the interposed therebetween has a structure in which the top 8 of the bead 7 is located at the position of the space 25 as shown in FIG.

When the metal gasket 16 is sandwiched between the opposed mounting surfaces of the cylinder head and the cylinder block and fastened by bolts or the like, the beads 7, 7 abut against each other and deform. Due to the reaction when the beads 7, 7 are crushed and deformed, the beads 7, 7 are formed between the opposing surfaces.
Forms an elastic annular contact portion where the surface pressure is sufficiently high around the bore hole 5 where high sealing performance is required,
The annular contact portion provides a sealing function for preventing a fluid such as a combustion gas passing through the bore hole 5 from leaking from the facing surface. In addition, the beads 7, 7 of the bead plates 17, 18
The inner and outer hem positions strongly contact the opposing mounting surface to form a seal in a face-to-face contact state, so that the sealing performance between the adjacent bore holes 5 where high-temperature combustion gas easily leaks can be ensured. it can. Since the degree of leakage of the combustion gas is low around the bore holes other than between the adjacent bore holes 5 as compared with between the adjacent bore holes, one bead composed of the beads 7, 7 is formed.

Since the metal gasket 16 is obtained by coating the intermediate plate 20 with the fluoro rubber 22, the seal between the intermediate plate 20 and the thin metal plate 21 is ensured. That is, the fluoro rubber 22 functions as a seal member between the intermediate plate 20 and the thin metal plate 21. The fluoro rubber 22 functions as a buffer when the bead 7 is pressed against the sub-plate 19 with a strong force. In particular, in this embodiment, not only the fluoro rubber 22 is provided between the intermediate plate 20 and the thin metal plate 21, but also the thickness of the fluoro rubber 22 Since the gap, that is, the space 25 is formed, the compression of the bead 7 is reduced by the step difference of the gap 25, and the thin metal plate 2 is formed.
1 deforms flexibly, and the buffering action is further enhanced. Therefore, in the metal gasket 16, the surface pressure is prevented from being concentrated, and a uniform surface pressure is obtained, and the sealing performance is further improved as compared with the metal gasket 1 of the first embodiment.

That is, when the metal gasket 16 is sandwiched between the opposed mounting surfaces of the cylinder head and the cylinder block and is fastened with bolts or the like, the beads 7, 7
Abut against each other and deform. At this time, bead 7
The thin metal plate 21 bends and deforms toward the space 25 due to the action of the top 8 of the space 25. However, since a layer of the fluorine rubber 22 exists on both sides of the space 25, the fluorine rubber 22 is deformed by the step corresponding to the thickness. As a result, the bead 7 can be prevented from being fully compressed. Therefore, also in this respect, the sealing performance of the metal gasket 16 is further improved as compared with the metal gasket of the first embodiment.

The specific dimensions and the like of the metal gasket in the second embodiment are shown below. Bead plate: 0.20-0.30mm (thickness), SUS3
01, 3 / 4H, H Intermediate plate: 0.12-0.15 mm (thickness), SUS43
0 Thin metal plate: 0.08 to 0.12 mm (thickness), SUS
430, SUS304 Heat-resistant rubber, heat-resistant resin: 0.02 to 0.03 mm (thickness), about 5 mm (width) However, the heat-resistant rubber and heat-resistant resin have an area of 1 to 1.5 mm corresponding to the bead. Has been removed.

In the first and second embodiments, a metal gasket in which stainless steel is used as a thin metal plate and heat-resistant rubber or heat-resistant resin is printed on an intermediate plate has been described. A relatively soft metal such as copper or iron (hardness rock ur R _B = about 50
-100) can achieve substantially the same functions and effects as those of the first and second embodiments without applying heat-resistant rubber or heat-resistant resin. In that case, diffusion welding or brazing can be adopted for welding the intermediate plate and the thin metal plate instead of spot welding.

The specific dimensions and the like of the metal gasket in the above embodiment are shown below. Bead plate: 0.20-0.30mm (thickness), SUS3
01, 3 / 4H, H Intermediate plate: 0.15 to 0.20 mm (thickness), SUS43
0 Thin metal plate: 0.10-0.15mm (thickness), soft metals such as Al, Cu, Fe

The engine to which the metal gasket of each of the above embodiments is applied is a fully open deck type or semi-open deck type engine, and a dry liner engine is particularly effective. In addition, this metal gasket is effective in application to an aluminum block engine because the surface pressure of the entire bead is dispersed and a seal portion in an average surface contact state is formed.

[0036]

Since the metal gasket according to the present invention is constructed as described above, a sub-plate having a buffer material interposed between an intermediate plate and a thin metal plate is sandwiched between a pair of bead plates and laminated. By using the elastic action of the cushioning material, the contact pressure concentrated on the top of the bead and the stress of the bead plate can be reduced, and the durability of the bead can be improved with a simple structure. be able to. In addition, since the cushioning material is interposed between the intermediate plate and the thin metal plate, the deformation of the bead of the bead plate is alleviated, the entire compression of the bead is prevented, and the surface pressure of the entire bead is averaged. Therefore, the sealing performance can be improved, and the bore distortion that is likely to occur between adjacent cylinder bores can be reduced.

In addition, since the metal gasket has an elastic effect of the cushioning material interposed between the intermediate plate and the thin metal plate in addition to the elastic effect of the bead, the cylinder head and the cylinder block during operation of the engine are operated. Therefore, it is easy to follow the change in the gap between the sealing member and the sealing member, so that stable sealing performance can be maintained for a long period of time.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a metal gasket according to the present invention.

FIG. 2 is a sectional view of the metal gasket shown in FIG. 1 taken along line AA.

FIG. 3 is a plan view showing an intermediate plate with heat-resistant rubber (an intermediate plate having heat-resistant rubber printed on its surface) used in the metal gasket shown in FIG.

4 is a cross-sectional view of the intermediate plate with heat-resistant rubber shown in FIG. 3 taken along line BB.

FIG. 5 is a cross-sectional view of the heat-resistant rubber-attached intermediate plate shown in FIG. 3 taken along line CC.

FIG. 6 is a metal gasket showing another embodiment according to the present invention, which is an AA of the metal gasket shown in FIG. 1;
It is arrow sectional drawing in the line.

7 is an intermediate plate with heat-resistant rubber of the metal gasket shown in FIG. 6 (an intermediate plate having heat-resistant rubber printed on its surface), and is a cross-sectional view taken along line BB of FIG.

8 is a cross-sectional view of the metal gasket shown in FIG. 6 taken along the line CC in FIG. 3, which is an intermediate plate with heat-resistant rubber.

[Explanation of symbols]

2,3,17,18 Bead plate 4,19 Sub plate 5 Bore hole 7 Bead 8 Bead top 9,20 Intermediate plate 10,21 Thin metal plate 11,22 Fluororubber (buffer material, heat resistant rubber or heat resistant resin) )

Claims (7)

[Claims] 1. A pair of elastic metal plates each having a bead formed along a periphery of a bore hole and arranged such that the tops of the beads are opposed to each other, and an intermediate plate disposed between the pair of elastic metal plates. Metal gasket
A metal gasket, characterized in that a thin metal plate which is in contact with the bead via a buffer material is laminated on the surface of the intermediate plate. 2. The metal gasket according to claim 1, wherein said cushioning member is made of heat-resistant rubber or heat-resistant resin. 3. The metal gasket according to claim 1, wherein the cushioning material is disposed on substantially the entire surface between the intermediate plate and the thin metal plate. 4. The metal according to claim 1, wherein the cushioning member is disposed between the intermediate plate and the thin metal plate except for a region corresponding to a top of the bead. Gasket made. 5. A gap corresponding to the thickness of the cushioning material is formed in a region where the cushioning material corresponds to the top of the bead before use, and the step of the gap reduces compression of the bead, The metal gasket according to claim 4, wherein the concentration of the surface pressure in the region at the top of the bead is reduced. 6. The metal according to claim 1, wherein the heat-resistant rubber or the heat-resistant resin constituting the cushioning material is disposed on the intermediate plate by printing. gasket. 7. The metal gasket according to claim 1, wherein the intermediate plate and the thin metal plate are fixed by welding.