JPH09287663A - Metal gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain gas sealing capability with a small thickness even under a high inner pressure by forming a stepped-off member consisting of a coating layer having high-load resistance at a bead formed out of at least one metallic sheet. SOLUTION: Openings of a bore hole 2a, an oil hole 2b, and a bolt hole 2c are formed at a single metallic sheet 1 to form a bead 3a at the peripheral edge of the opening. A step-off member 4 consisting of a coating layer having high-load resistance is fitted at the bead 3a. The coating layer employs a composite material where at least one selected from a group of synthetic resin, inorganic material and metallic powder is a main ingredient, and is made to adhere with a printing means, a metal spraying means or the like. The step-off member 4 is provided in the top region on the protruding surface side of the bead 3a. When it is fitted between flange surfaces, the bead 3a is compressed completely to reduce stress amplitude and draw out the reaction of the bead 3a to the maximum, thus generating large surface pressure. It is thus possible to ensure gas sealing capability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal gasket, and more particularly to a metal gasket having beads.

[0002]

2. Description of the Related Art As is well known, as the performance of internal combustion engines has improved in recent years, the demands on gaskets have become more stringent, and there is a demand for gaskets that can achieve a gas sealability against higher internal pressure with a thinner thickness. .

In response to such requirements, a metal sheet is used, and a grommet process or shim is welded to the periphery of the opening, a bead is formed, or an elastic seal member is attached to the seal, so that a seal having a larger surface pressure can be obtained. A metal gasket has been proposed in which a wire is provided at the peripheral edge of the opening so as to ensure the gas sealability.

However, in the metal gasket welded with the grommet, the seal line can be provided only in a specific portion such as the opening periphery, and when the flange surface is narrow, the seal width is insufficient and the grommet is applied. In addition, since the step amount is determined by the thickness of the grommet, the step amount is always constant and cannot be made smaller than a certain value. On the other hand, the beaded metal gasket has the advantage that it can be made thinner, but since the surface pressure generated is mainly determined by the bead size and shape, seal leakage due to bead fatigue etc. is easy. It happened to me. Further, in a metal gasket to which an elastic seal member is attached, it is difficult to control the compression amount of the elastic seal member, so the amount of application and shape of the elastic seal member must be redesigned for each gasket. Not only is it complicated, but there is a point where it lacks durability due to a large change over time, and moreover, it is easy to peel off due to mechanical vibration and the like and lose the gas sealability.

Furthermore, a metal gasket has been proposed in which an elastic seal member is attached to the bead to improve the fatigue resistance of the bead. However, while the surface pressure on the convex side of the bead is secured, the bead of the bead is secured. On the concave side, the tightening load was dispersed in three places, the elastic seal member portion and the bead rising portion, and a sufficient sealing surface pressure could not be secured.

[0006]

The present invention has the advantages of a metal gasket capable of achieving a gas sealability with a small thickness against a high internal pressure, and at the same time, is superior in improving fatigue resistance of a bead. It has excellent durability, and can reliably respond to higher internal pressure with a smaller tightening force, so deformation of the flange surface during mounting can be minimized, and mass production that can be manufactured at a lower cost is provided. Is to provide a metal gasket.

[0007]

The metal gasket according to the present invention is formed of at least one thin metal plate having a bead, and a stepping member made of a coating layer having high load resistance is provided on the bead. ing.

As a result, in the metal gasket of the present invention, the tightening load is concentrated on the portion where the stepping member is arranged to secure the sealing surface pressure, and the bead is completely compressed to reduce the stress amplitude of the bead. Alternatively, the fatigue resistance of the bead is improved by reducing the load stress on the bead by limiting the compression amount of the bead.

The metal gasket of the present invention may also have a stepped member attached to the top region of the bead on the convex side, thereby reducing the stress amplitude of the bead to improve fatigue resistance and at the same time the convex surface of the bead. And the surface pressure on the concave surface side is secured by the reaction force of the completely compressed bead.

The metal gasket of the present invention can further have a step member attached to the thickness region of the bead on the concave surface side, thereby restricting the bead compression amount and improving the fatigue resistance of the bead. The surface pressure on the concave side of the bead is secured by the stepped member.

The metal gasket of the present invention may also have a stepping member attached to the bead's convex top region and to the concave face's thickness region, respectively, thereby improving the fatigue resistance of the bead. At the same time, the surface pressure on the convex and concave surfaces of the bead is secured.

Further, the metal gasket of the present invention is formed of at least two metal thin plates which are laminated one above the other having beads at positions corresponding to each other, and a coating layer having a high load resistance. It is also possible to provide a step-forming member consisting of the bead convex surface between the concave surface of the bead of the upper metal thin plate and the convex surface of the bead of the lower metal thin plate corresponding to the bead or the thickness area on the bead concave surface side. .

The stepping member acts to reduce or restrict the amount of bead compression with respect to the upper metal sheet bead and to increase the bead compression amount with respect to the lower metal sheet bead, respectively. Thus, the fatigue resistance of the bead and the surface pressure on the convex and concave surfaces of the bead are secured.

Further, the metal gasket of the present invention is provided with a step member made of at least one selected from the group consisting of synthetic resin, inorganic material and metal powder or a composite material containing at least one selected from the group as a main component. It can also be formed. As a result, the stepping member having a predetermined thickness and a predetermined pattern is surely provided by the conventional printing means, the metal spraying means, or the dispenser, which improves the mass productivity and further reduces the manufacturing cost. It is possible.

Further, in the metal gasket of the present invention, the surface of the stepped member can be coated with a rubber coating, whereby the gas sealing property between the flange surface and the applied flange surface can be ensured.

Further, in the gasket of the present invention, the thickness of the rubber coating can be made thinner than the thickness of the stepping member, so that its elasticity increases the compression amount of the bead by the stepping member. Or it will not adversely affect regulations.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION A metal gasket according to an embodiment of the present invention has a single metal thin plate 1 having a bore hole 2a and an oil hole 2 as shown in FIG. 1 for a cylinder head gasket.
Predetermined openings such as b and bolt holes 2c are formed. Beads 3a surrounding the openings are formed on the periphery of these openings, and similar beads 3b are also formed on other portions that require an increase in surface pressure.

The required beads 3a or 3b (all beads if necessary) are provided with a stepping member 4 made of a coating layer having high load resistance.

As shown in FIG. 2, the step forming member 4 is provided in the top region D (see FIG. 3) on the convex surface side of the bead 3a (or 3b), whereby the flange surfaces F, F are formed.
When mounted in between, as shown in FIG. 4, the bead can be completely compressed to reduce the stress amplitude, and at the same time, the reaction force of the bead can be maximized to generate a larger surface pressure. As shown in FIG. 3, the “top region” is between the transition starting points C at which the transition from the top A of the bead to the slope B starts, and is selected from the surface Sa of the top A according to the required surface pressure. The boundary surface Sb separated by the thickness Ta of the stepped member
Means a region D defined between the convex surface of the bead and the convex surface of the bead.

At this time, the step forming member 4 has the top region D.
Since it is provided inside, it does not hinder the deformation at both end portions of the inclined portion B (see FIG. 3) of the bead that generates a surface pressure at the time of compression, so that the bead generated stress is not affected, and The load on the step forming member 4 due to the bead deformation can be minimized.

As the coating layer forming the step forming member 4, any member can be applied as long as it has high load resistance, but it can be surely provided with a predetermined thickness and a predetermined pattern. In order to ensure mass productivity, well-known printing means using at least one selected from the group of synthetic resins, inorganic substances and metal powders or a composite material containing at least one selected from the group as a main component. It is desirable to attach it by a metal spraying means or a dispenser.

Epoxy resins, polyamides, polyimides and the like can be used as synthetic resins suitable for forming a coating layer by a printing means or a dispenser, glass fibers, glass powders, ceramic powders and the like can be used as inorganic substances, and metal Stainless powder as powder,
Aluminum powder or the like can be used. Steel, aluminum, copper and the like can be used as the metal suitable for the metal spraying.

FIG. 5 is a view showing a metal gasket according to another embodiment of the present invention, which is constructed in the same manner as the above-mentioned embodiment except that the disposing position of the step forming member 4 is different.

The stepping member 4 in this embodiment is attached in the thickness region E (see FIG. 3) on the concave side of the bead 3. The "thickness region" is defined by the boundary surface Sd and the concave surface of the bead which are separated from the back surface Sc of the top portion A by the thickness Tb of the stepping member selected according to the required surface pressure as shown in FIG. Area E. Here, in the case of a trapezoidal bead as shown in the drawing, at least the portion of the stepped member 4 where the distance from the back surface Sc (see FIG. 3) of the bead top is the maximum is located on the side of the thickness region E. Therefore, it should be attached so as to be located between the transition starting points C so that the tightening load is not applied to the inclined portion B of the bead and hinders the deformation.

When mounted between the flange surfaces F, F, as shown in FIG. 6, the stepping member 4 acts to regulate the compression amount of the bead 3 to relieve the stress applied to the bead 3 and at the same time. The stepping member 4 serves as a concentrating point of the tightening load on the concave surface side of the bead, so that the surface pressure is not insufficient due to the dispersion of the tightening load on the concave surface side of the bead that occurs when the elastic sealing member described above is applied. .

FIG. 7 is a view showing a metal gasket according to another embodiment of the present invention, in which the stepping members 4a and 4 are provided on the top region D on the convex side of the bead 3 and the thickness region E on the concave side.
The configuration is the same as that of each of the above-described embodiments except that b is provided respectively.

The stepping member 4b acts to regulate the amount of compression of the bead 3 and relaxes the load stress on the bead, like the stepping member in the embodiment described with reference to FIGS. 5 and 6. At the same time, the stepping member 4b serves as a point of concentration of the tightening load on the concave surface side of the bead. On the other hand, the stepping member 4a compresses the bead to reduce the stress amplitude and at the same time draws out a larger reaction force of the bead, as in the stepping member in the embodiment described with reference to FIGS. 2 and 4. However, by having the step forming member 4b, it is not completely compressed. Therefore, the bead in the present embodiment can achieve improvement in fatigue resistance of the bead and generation of surface pressure in a higher dimension than the beads in the above-described embodiments. Further, by changing the thicknesses of the step-forming members 4a and 4b relatively, it is possible to manufacture a metal gasket which can more precisely correspond to a required surface pressure distribution and which is more durable.

FIG. 8 is a view showing a metal gasket according to still another embodiment of the present invention, in which at least two metal thin plates 1a and 1b which are laminated one above the other have beads 3c and 3d at positions corresponding to each other. The stepped member 4 similar to the above-described embodiment is provided between the concave surface of the bead 3c of the upper metal thin plate 1a and the convex surface of the bead 3d of the lower metal thin plate 1b. The stepping member 4 has a concave thickness region E of the bead 3c or a convex top region D of the bead 3d, as in the above-described embodiment.
Is provided.

As is clear from the description of each of the above-described embodiments, the step forming member 4 is located on the concave side of the bead 3c with respect to the bead 3c of the metal thin plate 1a. 3c acts to regulate the amount of compression, and acts on the bead 3d of the thin metal plate 1b so as to increase the amount of compression of the bead 3d by positioning the stepping member 4 on the convex side of the bead 3d. . As a result, the stepping member 4 in this embodiment can have the effects of the stepping member 4a and the stepping member 4b described in the embodiment of FIG.

The stepping member 4 is made of thin metal plates 1a and 1b.
The effect can be achieved by adhering to any of the above, but the stepping member 4 is damaged or peeled off in the process of laminating the metal thin plates 1a and 1b performed after the step of adhering the stepping member 4. It is preferable to provide it on the concave surface side of the bead which can be easily adhered with a predetermined thickness and pattern while preventing it from coming off, that is, the concave surface of the bead 3c of the upper metal thin plate 1a.

FIG. 9 is a view showing a metal gasket according to still another embodiment of the present invention, except that the surface of the stepped member 4 is covered with a rubber coating 5 except for the above-mentioned respective embodiments. It is constructed in the same way as the example. In addition,
In the illustrated case, the form shown in FIG. 2 is shown as an example, but it will be easily understood that the same can be applied to the other forms described above.

The rubber coating 5 is elastically interposed between the step forming member 4 and the flange surface F, so that the gas sealing property can be made more reliable. However, the rubber coating 5 is applied in a thickness that is sufficiently thin with respect to the thickness of the stepping member 4 so that its elasticity does not adversely affect the increase or regulation of the bead compression amount by the stepping member 4. Should be. A member applicable as such a rubber coating 5 is NB.
Examples thereof include R, fluororubber, and silicone rubber.

In each of the above-described embodiments, the bead has been described as a full bead shape having a trapezoidal shape, but the stepping member and the rubber coating are similarly applied even if the bead has another shape such as a semicircle or a mountain shape. It is possible to use.

[0034]

As described above, according to the present invention, since the bead is provided with the step forming member formed of the coating layer having high load resistance, the tightening load is applied to the disposing portion of the step forming member. Concentrate to secure the seal surface pressure,
By completely compressing the bead to reduce the stress amplitude of the bead, or by controlling the compression amount of the bead, the stress applied to the bead can be reduced and the fatigue resistance of the bead can be improved. Also, by attaching a step member to the apex area on the convex side of the bead so as to increase the compression amount of the bead, the stress amplitude of the bead is reduced to improve fatigue resistance, and the surface pressure on the convex surface of the bead is also improved. Can be ensured by the stepping member, and the surface pressure on the concave surface side can be ensured by the reaction force of the completely compressed bead. Further, by attaching a step member to the thickness region on the concave side of the bead so as to regulate the bead compression amount, the bead compression amount is regulated to improve the fatigue resistance of the bead and the bead concave surface. The surface pressure on the side can be secured by the stepped member. Furthermore, by adhering the stepping member to the top area on the convex side of the bead and the thickness area on the concave side, respectively, the fatigue resistance of the bead can be improved more effectively, and at the same time, the surface of the convex and concave sides of the bead can be improved. The pressure can be secured.

Further, the step forming member is formed by two metal thin plates, and the step forming member is provided between the concave surface of the bead of the upper metal thin plate and the convex surface of the bead of the lower metal thin plate. The bead fatigue resistance and the convexity of the bead, acting to reduce or regulate the amount of bead compression with respect to the bead of, and to increase the amount of bead compression with respect to the bead of the lower sheet metal, respectively. The surface pressure on the concave surface can be achieved more effectively. Further, by attaching the stepping member to the thickness region on the concave surface side of the bead of the upper metal thin plate, the stepping member can be attached to the predetermined position with the predetermined thickness more easily and more accurately.

In addition, by forming the step-forming member from at least one selected from the group consisting of synthetic resin, inorganic material and metal powder or a composite material containing at least one selected from the group as a main component, The stepping member having a predetermined thickness and a predetermined pattern can be reliably provided by the printing means, the metal spraying means, or the dispenser, the mass productivity can be improved, and the manufacturing cost can be further reduced. Furthermore, by coating the surface of the stepping member with a thin rubber coating, the gas sealing property between the flange surface and the surface of the flange can be more secured without adversely affecting the increase in the amount of bead compression by the stepping member or regulation. Can be secured.

[Brief description of drawings]

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

FIG. 2 is a schematic enlarged cross-sectional view taken along the line II-II in FIG.

FIG. 3 is a schematic cross-sectional view for explaining a “top region” and a “thickness region”.

FIG. 4 is a schematic enlarged cross-sectional view showing a state in which the bead shown in FIG. 2 is mounted between flange surfaces.

FIG. 5 is a schematic enlarged sectional view similar to FIG. 2, showing a metal gasket according to another embodiment of the present invention.

6 is a schematic enlarged cross-sectional view showing a state in which the bead shown in FIG. 5 is mounted between flange surfaces.

FIG. 7 is a schematic cross-sectional view similar to FIG. 2, showing a metal gasket according to still another embodiment of the present invention.

FIG. 8 is a schematic sectional view similar to FIG. 2, showing a metal gasket according to still another embodiment of the present invention.

9 is a schematic sectional view similar to FIG. 2, showing a metal gasket according to still another embodiment of the present invention.

[Explanation of symbols]

 1, 1a, 1b Metal thin plate 3, 3a, 3b, 3c, 3d Bead 4, 4a, 4b Stepping member 5 Rubber coating D Top area E Thickness area

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Suzuki 2894 Kokuzu, Odawara-shi, Kanagawa Within Ishino Gasket Industry Co., Ltd. 72) Inventor Osawa Nanami 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Hideki Muramatsu 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd.

Claims (8)

[Claims] 1. A metal gasket formed by at least one thin metal plate having a bead, wherein the bead is provided with a stepping member made of a coating layer having high load resistance. 2. The metal gasket according to claim 1, wherein the step forming member is attached to a top region of the bead on the convex side. 3. The metal gasket according to claim 1, wherein the step forming member is attached to a thickness region of the bead on the concave surface side. 4. The metal gasket according to claim 1, wherein the step forming member is attached to each of a top region on a convex surface side and a thickness region on a concave surface side of the bead. 5. A concave surface of a bead of an upper metal thin plate and a lower metal thin plate corresponding to the bead, which are formed by at least two metal thin plates which are vertically stacked and each of which has a bead at a position corresponding to each other. A metal gasket, wherein a stepping member made of a coating layer having a high load resistance is provided in a top region on the bead convex side or a thickness region on the bead concave side between the convex surface of the bead. 6. The step forming member is made of at least one selected from the group consisting of a synthetic resin, an inorganic material and a metal powder, or a composite material containing at least one selected from the group as a main component. The metal gasket according to any one of claims 1 to 5. 7. The metal gasket according to claim 6, wherein the surface of the stepped member is covered with a rubber coating. 8. The metal gasket according to claim 7, wherein the thickness of the rubber coating is smaller than the thickness of the step forming member.