JPH05240354A - Metal layered gasket - Google Patents

Abstract

PURPOSE:To provide excellent sealing and spring characteristics of a gasket to be used for an exhaust manifold part of an engine by folding the peripheral end of a fluid channel hole of a pair of beaded thin plates to the inside, and by having it worked as a gas stopper. CONSTITUTION:A metal layered gasket for exhaust manifold comprises a heat- resisting metallic material: a pair of beaded thin plates 1a, 1b on which bead parts 3a, 3b protruded inward are formed around a fluid channel hole 2, an intermediate plate 5 layered between the respective thin plates 1a and 1b except for the surrounding of the fluid channel hole 2, and an annular intermediate plate structure 6 layered between the peripheral parts of the fluid channel hole 2. The peripheral end of the fluid channel hole 2 of the thin plate 1a and/or the thin plate 1b is folded inward, while the size of the radius of points where the bead parts 3a, 3b are formed, is differed from one another. Ceramic or heat-resisting alloy steel is used as the intermediate plate structure 6, and the beads 3a, 3b are abutted on the inner and outer peripheral parts of the structure and are layered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal laminated gasket used between mounting surfaces of a pair of structures, for example, a cylinder head portion, an exhaust manifold portion and the like.

[0002]

2. Description of the Related Art Conventionally, gaskets that are clamped between a cylinder block and a cylinder head or between a cylinder head and an exhaust manifold and tightened with tightening bolts are arranged so that combustion gas and exhaust gas do not leak from their joint surfaces. A gasket made of a material such as asbestos is used as a typical example.

However, recently, in high-performance engines for automobiles aiming at weight reduction, downsizing of engines, or high output directivity,
Use of a cylinder head made of aluminum alloy for weight reduction increases thermal expansion or contraction due to temperature changes, increases in thermal deformation of gasket mounting surface or mounting flange due to thinning of the exhaust manifold, and during engine use Due to the stress applied to the gasket due to the cold heat cycle condition, that is, the heat load, many defects such as a gas leak phenomenon due to the destruction of the gasket and a rapid decrease in the sealing surface pressure may occur. Therefore, a method of using a metal gasket has been generally known as an effective sealing means that can replace a conventional gasket such as asbestos, and various gaskets have been developed for the metal gasket.

For example, Japanese Utility Model Publication No. 62-116149 discloses a metal laminated manifold gasket for an internal combustion engine. This has a structure in which the metal laminated plates are not fixed to each other by means such as folding back in the gas flow hole portion, and among the metal laminated plates, seal beads are provided around the gas flow holes of the two middle plates adjacent to each other. The seal beads are provided facing each other or facing each other, and a stainless steel plate is placed on the surface of one outer plate that contacts the exhaust manifold, and the surface of the other outer plate that contacts the cylinder head is rustproofed. Then, the metal laminated plates are integrally formed by using a joining means such as spot welding.

Further, Japanese Utility Model Laid-Open No. 2-61169 discloses that
A metal laminated gasket for a manifold is disclosed. This is sandwiched between the end face of the mounting flange of the exhaust manifold and the side face of the cylinder head where the exhaust discharge port is opened, and at least three or more thin metal plates are stacked in a non-bonded state without being fixed to each other. The metal thin plate is composed of a thin plate with a bead for sealing, and at least one surface of the middle plate of the metal thin plate is composed of a thin plate coated with a heat insulating material made of a mixture of a ceramic material and a metal material having smoothness, The beaded thin plates located on both sides have bead portions arranged opposite to each other, or the beaded thin plates located on both sides have bead portions disposed opposite to each other.

Further, in Japanese Utility Model Laid-Open No. 2-61170,
A laminated gasket for a manifold is disclosed. This is clamped between the end face of the mounting flange of the exhaust manifold and the side face of the cylinder head where the exhaust discharge port is opened.
At least three or more metal thin plates are laminated in a non-bonded state without being fixed to each other, the metal thin plates on both sides are composed of thin plates with a bead for sealing, and at least one surface of the middle plate of the metal thin plates is a smooth surface. Of the heat insulating material such as ceramics, the thin plates with beads located on both sides have bead portions arranged opposite to each other, or the thin plates with beads located on both sides have bead portions opposite to each other. It is arranged in.

[0007]

By the way, a metal laminated gasket having a structure in which a plurality of metal thin plates as described above are superposed has excellent flexibility and excellent heat resistance.
By incorporating a bead structure, it is known that it has an appropriate compressibility and is economical because it does not deteriorate the sealing performance, but the maximum temperature on the gasket mounting surface reaches 750 to 900 ° C. Therefore, even if the gasket is made of a metal material, the compression recovery,
It is not easy to maintain various gasket properties such as sealability, deformation resistance, sag resistance, and strength. Especially with the recent high performance of the engine, the exhaust temperature has become higher,
Due to an increase in strain on the mounting surface of the exhaust manifold and the like, there are many problems with respect to compression recovery at high temperatures, and a highly reliable gasket is currently demanded.

An object of the present invention is to solve the above-mentioned problems, and by utilizing the advantages of the bead plate of the metal laminated gasket, reliability that secures various characteristics such as high temperature compression restoring property, sealing property and strength. To provide a high gasket.

[0009]

The present invention has been made to solve the above-mentioned problems, and is made of a metal material having excellent heat resistance, and is formed inwardly around each of the opened fluid passage holes. A pair of beaded thin plates having protruding bead portions, an intermediate plate laminated between the beaded thin plates excluding the periphery of the fluid passage hole, and a ring-shaped middle plate laminated between the fluid passage hole peripheral portions. In a metal laminated gasket consisting of a structure, one or both of the pair of beaded thin plates is folded inward at the periphery of the fluid passage hole, and the bead part of one beaded thin plate and the bead part of the other beaded thin plate The ceramics or heat-resistant alloy steel is used as the middle plate structure, and the bead portion of the beaded thin plate is laminated in the abutting state on the outer peripheral edge of the middle plate structure while varying the radius of the formation position of the middle plate structure body. This It is summarized as metal laminate type gasket according to claim.

[0010]

As described above, when one or both of the pair of thin plates with beads are folded inward at the periphery of the fluid passage hole, when the gasket is compressed, the folded-back portion is
It acts as a stopper so as to ensure the compression restoring property of the bead portion formed on the outer diameter portion and the intermediate plate structure sandwiched in contact with the bead portion, and the bead portion of one thin plate with a bead. And the radius of the formation position of the bead portion of the other beaded thin plate is made different in size, and ceramics or heat-resistant alloy steel is used as the middle plate structure, and the beaded thin plate of the middle plate structure has an outer peripheral edge portion. By stacking the bead portion in the abutting state, the intermediate plate structure and the bead portion work together so that excellent spring characteristics and sealing characteristics are exhibited.

[0011]

EXAMPLE An example of the metal laminated gasket according to the present invention will be described below with reference to the exhaust manifold gasket shown in the drawings. 1 is a plan view of an exhaust manifold gasket, FIG. 2 is an enlarged sectional view taken along the line AA of FIG. 1, and FIGS. 3 and 4 show a portion corresponding to the line AA of FIG. 1 in another embodiment. It is an expanded sectional view.

In FIG. 2 showing the first embodiment, 1a, 1b
Is a pair of thin plates with beads and is made of a metal material having excellent heat resistance, for example, SUS304, SUS310, SUH309 (Hv = 200 or less). Projecting bead portions 3a, 3b are formed,
In addition, folding edges 4a and 4b that are folded back inward are formed on the periphery of the fluid passage hole 2. The bead portions 3a, 3
For the bead shape of b, the thickness of the thin plates with beads 1a and 1b is t
, The bead height is 1 to 3 t and the bead width is 1 to
Within the range of 3t, the bead portion 3 of one thin plate 1a with a bead
The radius of the formation position of the bead portion 3b of the other beaded thin plate 1a is formed to be larger than the formation position radius of a (centering around the fluid passage hole 2). Further, 5 is an intermediate plate, which is a beaded thin plate 1a excluding the periphery of the fluid passage hole 2,
It is laminated between 1b. Further, 6 is ceramics or heat-resistant alloy steel (for example, Inconel 625, Inconel 718).
, JIS NCF600 NCF750 etc.), wherein the bead portions 3a, 3b of the beaded thin plates 1a, 1b are in contact with the inner peripheral edge portion of the inner plate structure 6 in a circular shape. The layers are stacked, and the shape thereof is a ring shape corresponding to the shape of the fluid passage hole 2. The circular middle plate structure is easy to manufacture and ensures accuracy, and
This is because it can be manufactured at low cost with low material cost.

In FIG. 3 showing the second embodiment, the folded edges 4a and 4b are not simply folded but strongly compressed to have a thickness of 2t-α, and the bead portions 3a and 3b and the intermediate plate structure 6 are compressed. Since the amount is adjusted and the other structure is the same as that of the first embodiment, the description thereof will be omitted.

In FIG. 4 showing the third embodiment, the folded edge 4a is formed only on the beaded thin plate 1a, and the compression amounts of the bead portions 3a and 3b and the intermediate plate structure 6 are adjusted. Since other configurations are the same as those in the first embodiment, the description thereof will be omitted.

In the above embodiment, the case where a single middle plate structure is used has been described, but the plate thickness and the number of plates are not limited and can be arbitrarily selected.

[0016]

According to the above-described metal laminated gasket of the present invention, when the gasket is compressed by folding inward the inner edges of the fluid passage holes of one or both of the pair of beaded thin plates. , The folded portion acts as a stopper, and the bead portion formed on the outer diameter of the bead portion and the intermediate plate structure sandwiched in contact with the bead portion at the time of high temperature are ensured in compression recovery, The radius of the formation position of the bead portion of one beaded thin plate and the bead portion of the other beaded thin plate is made different in size, and ceramics or heat-resistant alloy steel is used as the middle plate structure, and the inside and outside of the middle plate structure By stacking the bead portion of the thin plate with beads on the peripheral portion in a contact state, excellent spring characteristics and sealing characteristics can be obtained in cooperation with the intermediate plate structure and the bead portion.

[Brief description of drawings]

FIG. 1 is a plan view of an exhaust manifold gasket according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 3 is an enlarged cross-sectional view of a portion corresponding to line AA of FIG. 1 according to the second embodiment.

FIG. 4 is an enlarged cross-sectional view of a portion corresponding to line AA of FIG. 1 according to the third embodiment.

[Explanation of symbols]

 1a, 1b Thin plate with bead 2 Fluid passage hole 3a, 3b Bead part 4a, 4b Folding edge 5 Intermediate plate 6 Intermediate plate structure

Claims (2)

[Claims] 1. A pair of beaded thin plates (1) made of a metal material having excellent heat resistance and formed with bead portions (3a, 3b) projecting inwardly around an opened fluid passage hole (2).
a, 1b, an intermediate plate 5 laminated between the beaded thin plates excluding the periphery of the fluid passage hole 2, and a ring-shaped middle plate structure 6 laminated between the peripheral portions of the fluid passage hole 2. In this metal laminated gasket, the peripheral edge of one or both fluid passage holes 2 of the pair of beaded thin plates 1a, 1b is folded back inward, and the bead portion 3a of one beaded thin plate 1a is folded.
And the radius of the formation position of the bead portion 3b of the other thin plate with bead 1b is made different in size, and ceramics or heat-resistant alloy steel is used as the middle plate structure 6, and the inner plate structure 6 has inner and outer peripheral portions with A metal laminated gasket characterized in that the bead portions 3a, 3b of the beaded thin plates 1a, 1b are laminated in contact with each other. 2. The metal laminated gasket according to claim 1, wherein the intermediate plate structure 6 is formed of a plurality of laminated bodies.