JPH1163229A - Laminated metallic gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thick-laminated metallic gasket with a thickness not smaller than 1 mm, which has a minimized number of layers and sufficient sealing performance, at low cost. SOLUTION: A laminated metallic gasket comprises a lamination made of a bead board 1 formed with an annularly projected bead 5 around its fluid passing hole 3 to be sealed and of a thick metal plate 2. The metal plate 2 is formed at its position adapted to contact with the bead 5 with an annular recession 6 for holding at least the crest 51 of the bead 5, and is deformed at the recession portion into a shape having springiness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated metal gasket used for a cylinder head gasket of an automobile engine, for example.

[0002]

2. Description of the Related Art In an engine designed to use a cylinder head gasket mainly composed of a sheet of a soft sealing material such as an admixture of heat-resistant fiber and rubber or graphite, the gasket is replaced with a laminated metal gasket. In the case of replacement, a thick laminated metal gasket having a thickness of 1.0 mm or more may be required.

Conventionally, such a thick laminated metal gasket has been formed by laminating four or more metal plates as shown in FIG. 5, for example. That is, the relatively thick adjustment plate 1 having the combustion chamber hole 15 and having a thickness of, for example, 0.4 mm.
On one side, a folded plate 12 made of a comparatively thin metal plate having a thickness of, for example, 0.1 mm and having a folded portion 16 on the periphery of the combustion chamber hole 15 is laminated, and the adjustment plate 11 and the folded plate 12 are further laminated. On each of the outer surfaces,
A gasket was formed by laminating bead plates 13 and 14 having a thickness of, for example, 0.3 mm and having a bead 17 surrounding the combustion chamber hole 15 on the outer side of 6.

[0004]

In a laminated metal gasket having a large number of laminated layers as described above, for example, a sealing material layer made of a relatively expensive fluorine rubber or the like which covers the surface of the metal plate is used to form a multilayer metal plate. There is a regret that the cost of materials and processing increases, such as the need to cover each surface, and the cost of manufacturing gaskets increases.

In order to reduce the number of laminated layers of the laminated metal gasket, it is conceivable to further increase the thickness of the adjusting plate and to adopt a two-layer structure of the adjusting plate and the bead plate. The bead of the plate is fully bent, and the bead is easily broken, and the sealing performance cannot be maintained for a long time. In addition, when the thickness of the adjustment plate is so large, the elastic deformation capability of the adjustment plate is reduced, so that the followability to the elastic deformation of the bead is reduced and the distortion of the surface with which the adjustment plate comes into contact is reduced. There is a problem that the ability to absorb and compensate is reduced and the sealing performance of the gasket is impaired.

The present invention has been made in view of the above points, and an object of the present invention is to provide a gasket having a thickness of 1 mm or more without impairing the sealing performance of the gasket even if the thickness of the adjusting plate is increased. It is an object of the present invention to realize a low-cost laminated metal gasket which can be constructed with a minimum number of laminated layers.

[0007]

A laminated metal gasket according to the present invention, which achieves the above object, comprises a metal plate having elasticity, and has a ridge bead at a peripheral portion of a fluid flow hole to be sealed so as to surround the hole. A bead plate and a thick metal plate are laminated, and the thick metal plate is provided with a concave portion capable of accommodating at least the vicinity of the top of the bead at a position where the top of the convex bead abuts, in an annular shape, It is characterized in that the concave portion is deformed into a shape imparting springiness.

In the laminated metal gasket of the present invention,
As described above, the thick metal plate is provided with an annular concave portion that can accommodate at least the vicinity of the top of the bead at a position where the top of the ridge bead of the bead plate contacts. Therefore, even if the gasket is composed of a two-layer metal plate of a bead plate provided with a ridged bead and the thick metal plate, the ridge of the bead plate is tightened when the gasket is tightened and during use of the gasket. The bead never bends. Therefore, set of the bead is prevented, and the sealing performance can be maintained for a long time.

In the present invention, since the thick metal plate is deformed into a shape imparting springiness in the annular concave portion, the thick laminated metal gasket having a thickness of 1.0 mm or more is combined with the bead plate and the thick plate. Even when the thickness of the thick metal plate is increased to a thickness of, for example, 0.7 to 1.2 mm so that the thick metal plate is formed of two layers with the metal plate, the thick metal plate is Can be deformed in accordance with the elastic deformation of the sheet metal, and the distortion of the surface in contact with the thick metal can be well absorbed and compensated, and good sealing performance can be maintained.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details and embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a laminated metal gasket G1 according to a first embodiment of the present invention, and FIG. 2 is an enlarged sectional view taken along line XX of FIG. The laminated metal gasket shown in FIGS. 1 and 2 is used as a cylinder head gasket. A cooling water passage is provided outside of a fluid flow hole 3, that is, a combustion chamber hole and a bolt hole 4 for fastening bolts disposed around the hole. Although holes and oil passage holes are provided, these are not shown for simplification of the drawing.

The laminated metal gasket G1 is made of a highly elastic metal plate such as stainless steel, and has a fluid passage hole 3 to be sealed.
And a thick metal plate 2 made of a stainless steel plate, a steel plate, or the like. . The thickness of the bead plate 1 is usually in the range of 0.15 to 0.35 mm, and if the thickness of the gasket G1 is 1.1 mm and the thickness of the bead plate is 0.3 mm, the thickness of the thick metal plate The thickness becomes 0.8 mm.

The thick metal plate 2 has an annular recess 6 having a width and depth capable of accommodating at least the vicinity of the top 51 of the convex bead 5 at a position where the top 51 of the convex bead 5 abuts on the bead plate 1. In addition, the concave portion 6 and its peripheral portion are deformed into convex portions 7 so as to be curved in a mountain shape protruding in the same direction as the projecting direction of the convex bead 5. In processing the thick metal plate, after forming the concave portion 6 by coining, cutting, etching, or the like, the concave portion 6 and its peripheral portion are deformed in the same manner as when forming a convex bead having a cross-sectional shape of a mountain shape. It is convenient to form the ridge 7 curved in a mountain shape. When the recess 6 is formed by coining, it can be processed simultaneously with the formation of the ridge 7.

At this time, in the gasket G1 of the first embodiment, the concave portion 6 is curved and deformed so as to be located at the bottom of the concave surface 8 of the ridge 7. As described above, the recess 6 has a width and a depth that can accommodate at least the vicinity of the top of the convex bead 5 of the bead plate 1, and the width of the recess 6 is, for example, 1.0 mm, and is usually 0.5 to 2.0 mm. Is selected in the range. The depth of the concave portion is formed to be about 0.02 to 0.10 mm.

Since the laminated metal gasket G1 is configured as described above, the two-layered metal gasket G1
In the layer configuration, a thick gasket having a total thickness of the metal plate of 1.0 mm or more can be formed as described above, and
For example, when the gasket is tightened between the joining surfaces of the cylinder head and the cylinder block, the vicinity of the top 51 of the convex bead of the bead plate 1 is accommodated in the concave portion 6 of the thick metal plate, so that the convex bead 5 is entirely It does not bend and can prevent the set bead from sagging, and can maintain the sealing performance for a long period of time.

Further, since the thick metal plate 2 is bent and deformed in the shape of a mountain in the concave portion 6 and the periphery thereof, and the deformation imparts the spring property, the thick metal plate can bead regardless of its thickness. It can well follow the elastic deformation of the ridge bead 5 of the plate, and can absorb and compensate for the distortion of the joint surface where the thick metal plate abuts. The thick metal plate 2 can also be formed of an inexpensive ordinary steel plate.

The depth of the recess 6 can be varied depending on the position around the fluid flow hole 3. That is, between the fluid flow holes 3 and 3 (A in FIG. 1) under severe sealing conditions, the depth of the concave portion 6 is reduced, and a portion close to the bolt hole to which a large tightening force is applied (B in FIG. 1). In (2), the depth of the recess 6 is increased. An intermediate depth is set between bolt holes (C in FIG. 1) other than between the fluid flow holes.

Further, the spring constant of the convex bead 5 is made different depending on the position around the fluid flow hole 3 so that the spring constant is large in the above A, the spring constant is small in the above B, and an intermediate spring constant in the above C. When the ridge bead is formed on the ridge and the height and width of the ridge bead 5 are changed correspondingly, the depth and the width of the recess 6 can be changed correspondingly. The width of the concave portion 6 may be large enough to accommodate the entire convex ridge bead 5, but in order for the concave portion 6 to function to prevent the bead from bending,
It is sufficient if there is a width (usually 15 to 70% of the width of the bead) that can accommodate the vicinity of the top 51 of the ridge bead 5.
A recess having such a width is easier to mold. The edge portion 61 of the concave portion 6 is sufficiently rounded so as to be round.

FIG. 3 is an enlarged sectional view similar to FIG. 2 of a laminated metal gasket G1 'according to a modification of the first embodiment of the present invention. In the gasket G1 'of this modification, the thick metal plate 2 is deformed so as to be curved in a mountain shape protruding in the direction opposite to the direction in which the convex bead 5 of the bead plate 1 protrudes in the concave portion 6 and its periphery. With a ridge 7 and a recess 6
Is located at the top of the ridge 7. Other than this point, FIGS.
Is the same as the laminated metal gasket G1 of the first embodiment shown in FIG. The same reference numerals as those in FIG. 2 indicate the same parts.

FIG. 4 is an enlarged sectional view similar to FIG. 2 of a laminated metal gasket G2 according to a second embodiment of the present invention.
1 and 2 denote the same parts. The gasket G2 of the second embodiment is formed of a two-layer metal plate of a bead plate 1 provided with a ridged bead 5 and a thick metal plate 2, similarly to the gasket G1 of the first embodiment. It has a thickness exceeding 1.0 mm. Bead plate 1
Is the same as in the gasket G1 of the first embodiment, and the thick metal plate 2 is also provided with the concave portion 6 at the position where the convex bead 5 contacts.
This is similar to the gasket of the first embodiment.

However, the thick metal plate 2 of the gasket G2 according to the present embodiment does not have a ridge which is deformed so as to be curved in a mountain shape.
Alternatively, the surface 2 on the side with the recess 6 and the surface 2 on the opposite side
An arc-shaped concave portion 9 is formed at a position corresponding to the second concave portion 6, and the thick metal plate 2 is provided with a spring property by the concave portion 9. In the gasket G2 of the present embodiment, the widths of the concave portion 6 and the concave portion 9 are substantially the same as the width of the convex bead, and the two legs 52, 53 of the convex bead 5 and the concave portion 9 are provided.
Seal lines are formed symmetrically with both ends 91 and 92 in the width direction.

The embodiments and modified examples of the present invention described above can be appropriately modified within the scope of the present invention. Also,
The laminated metal gasket of the present invention is not necessarily limited to a two-layer structure of a bead plate and a thick metal plate, and an appropriate metal plate such as a surface plate and an adjusting plate is added as long as the features of the present invention are maintained. A thick gasket having a thickness of 1.0 mm or more may be formed as a three-layer structure. Compared to a conventional gasket consisting of four or more layers, even in the case of a three-layer structure, a sufficient cost reduction effect can be achieved as in the case of the two-layer structure.

[0022]

As described above, according to the present invention,
A laminated metal gasket having a thickness of 1.0 mm or more can be formed with a minimum number of layers. Therefore, the manufacturing cost can be significantly reduced as compared with a conventional metal gasket having a large number of laminated layers, because the covering area of a relatively expensive sealing material layer made of fluoro rubber or the like which covers each plate is significantly reduced.

Moreover, when the gasket is tightened between the surfaces to be sealed, the convex bead of the bead plate is accommodated at least in the vicinity of the top in a recess formed in the thick metal plate at a position where the top abuts. Since the concave portion functions as a stopper and prevents the entire bend of the convex bead, settling of the convex bead during long-term use of the gasket is prevented, and the sealing performance of the convex bead can be maintained for a long time.

Since the thick metal plate is deformed into a shape imparting spring property at the concave portion,
Despite the thickness being large, it can well follow the elastic deformation of the ridge bead, and can well absorb and compensate for the distortion of the sealing surface surface with which the thick metal plate abuts, and can maintain good sealing performance. The thick face plate can also be made of inexpensive ordinary steel, in which case the production costs are further reduced.

[Brief description of the drawings]

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

FIG. 2 is an enlarged sectional view taken along line XX of FIG.

FIG. 3 is an enlarged sectional view of a modification of the first embodiment.

FIG. 4 is an enlarged sectional view of a laminated metal gasket according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of a conventional thick metal gasket.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bead plate 2 Thick metal plate 3 Fluid flow hole 5 Convex bead 6 Concave portion 7 Convex ridge 9 Recess

Claims (5)

[Claims] 1. A bead plate comprising a metal plate having elasticity and provided with a ridge bead on a peripheral portion of a fluid flow hole to be sealed so as to surround the same, and a thick plate metal plate. The thick metal plate is provided with a concave portion capable of accommodating at least the vicinity of the top portion of the bead at a position where the top portion of the convex bead abuts, and is deformed into a shape imparting springiness at the portion of the concave portion. The laminated metal gasket characterized by the above. 2. The laminated metal gasket according to claim 1, wherein the thick metal plate is deformed so as to be curved in a chevron at the concave portion. 3. The laminated metal gasket according to claim 1, wherein the thick metal plate is provided with an arc-shaped concave portion at a position corresponding to the concave portion on a surface opposite to a surface where the concave portion is located. 4. The laminated metal gasket according to claim 1, wherein the depth of the recess differs depending on the position around the fluid flow hole. 5. The laminated metal gasket according to claim 1, wherein the bead plate is made of a highly elastic metal plate such as a stainless steel plate, and the thick metal plate is made of an inexpensive ordinary steel plate.