JP2787041B2 - Metal laminated gasket - Google Patents

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 a mounting surface 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 which are sandwiched between a cylinder block and a cylinder head or between a cylinder head and an exhaust manifold and are tightened with tightening bolts or the like are arranged so that combustion gas and exhaust gas do not leak from respective joint surfaces. A gasket made of a material such as asbestos is used as a typical example.

However, recently, in high-performance automobile engines aiming at lightening, downsizing, or high output power of the engine,
Increase in thermal expansion or contraction due to temperature change due to the adoption of a cylinder head made of aluminum alloy for weight reduction, increase in thermal deformation of the 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, that is, the heat load, depending on the cooling / heating cycle conditions, many problems such as gasket breakage and a gas leak phenomenon due to a sharp decrease in sealing surface pressure may occur. Therefore, a method using a metal gasket is generally known as an effective sealing means as a substitute for a gasket such as a conventional asbestos, and various gaskets have been developed for the metal gasket.

For example, Japanese Utility Model Laid-Open Publication No. Sho 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 of folding or the like in the gas flow hole portion, and among the metal laminated plates, a seal bead is formed around the gas flow holes of two adjacent middle plates. Provided, the seal beads are opposed to each other and opposed to each other, and the stainless steel plate is arranged on the surface of one of the outer plates in contact with the exhaust manifold, and the rust prevention treatment is performed on the surface of the other outer plate in contact with the cylinder head. Then, each metal laminate is formed into an integral structure using joining means such as spot welding.

In Japanese Utility Model Laid-Open No. 2-61169,
A laminated metal gasket for a manifold is disclosed. This is sandwiched between the end surface of the mounting flange of the exhaust manifold and the side surface of the cylinder head with the exhaust discharge port opened, and at least three or more thin metal plates are laminated in a non-joined 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 formed 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 disposed on opposite sides, or the beaded thin plates located on both sides have bead portions disposed on opposite sides.

Furthermore, Japanese Utility Model Laid-Open No. 2-61170 discloses that
A 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 of the cylinder head with the exhaust discharge port opened,
At least three or more metal thin plates are laminated in a non-joined state without being fixed to each other, and the metal thin plates on both sides are formed of thin plates with sealing beads, and at least one surface of the metal thin plate has a smooth surface. The beaded thin plates located on both sides are provided with bead portions on opposite sides, or the beaded thin plates located on both sides are located on opposite sides of the bead portions. It is arranged in.

[0007]

By the way, a metal-laminated gasket having a structure in which several thin metal sheets are stacked as described above is rich in flexibility and excellent in heat resistance.
It is known that incorporating a bead structure has moderate compressibility and is economical with little deterioration in sealing performance.However, the maximum temperature of the gasket mounting surface reaches 750 to 900 ° C. Therefore, even if a gasket is made of a metal material,
It is not easy to maintain various properties of the gasket, such as sealability, deformation resistance, sag resistance, and strength. In particular, the exhaust temperature has risen further with the recent high performance of engines,
Due to an increase in the distortion of the mounting surface of the exhaust manifold and the like, there are many problems regarding the compression resilience at high temperatures, and a gasket with high reliability is currently required.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to make use of the advantages of a bead plate of a metal-laminated gasket, to ensure reliability such as high-temperature compression restorability, sealing properties, and strength. To provide a high gasket.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and is made of a metal material having excellent heat resistance. A pair of beaded thin plates having a projecting bead portion, 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 edges In the metal-laminated gasket comprising a structure, the periphery of one or both fluid passage holes of the pair of beaded thin plates is turned inward, and a bead portion of one beaded thin plate and a bead portion of the other beaded thin plate. The radius of the formation position was varied, and ceramic or heat-resistant alloy steel was used as the middle plate structure, and the bead portion of the beaded thin plate was laminated on the outer peripheral portion of the middle plate structure in a contact state. This It is summarized as metal laminate type gasket according to claim.

[0010]

As described above, when the gasket is compressed by folding the periphery of one or both fluid passage holes of the pair of beaded thin plates inward, the folded portion becomes:
The bead portion formed on the outer diameter portion and the bead portion of the thin plate with one bead act as a stopper so as to secure the compression restoring property of the intermediate plate structure sandwiched in a contact state with the bead portion. And the radius of the formation position of the bead portion of the other beaded sheet is made to be different in size, and ceramics or heat-resistant alloy steel is used as the intermediate plate structure, and in the intermediate plate structure, the outer peripheral edge portion of the beaded thin plate is used. By laminating the bead portions in a contact state, the intermediate plate structure and the bead portion work together to exhibit excellent spring characteristics and sealing characteristics.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a metal laminated gasket according to the present invention will be described below with reference to a gasket for an exhaust manifold shown in the drawings. 1 is a plan view of a gasket for an exhaust manifold, FIG. 2 is an enlarged sectional view taken along line AA in FIG. 1, and FIGS. 3 and 4 are views of a portion corresponding to the line AA in FIG. It is an expanded sectional view.

In FIG. 2 showing the first embodiment, 1a and 1b
Is a pair of beaded thin plates made of a metal material having excellent heat resistance, for example, SUS304, SUS310, SUH309 (Hv = 200 or less). Projecting bead portions 3a and 3b are formed,
Further, on the peripheral edge of the fluid passage hole 2, there are formed folded edges 4a and 4b which are folded inward. The bead portions 3a, 3
The bead shape of b is such that the thickness of the beaded thin plates 1a and 1b is t
When the height of the bead is 1 to 3t, the width of the bead is 1 to
3t, and the bead portion 3 of one beaded thin plate 1a
The radius of the bead portion 3b of the other beaded thin plate 1a is formed to be larger than the radius of the formation position of a (centering on the fluid passage hole 2). Reference numeral 5 denotes an intermediate plate, which is a thin plate 1a with a bead except for the periphery of the fluid passage hole 2,
1b. 6 is ceramics or heat-resistant alloy steel (for example, Inconel 625, Inconel 718)
, JIS NCF600, NCF750, etc.), and the beaded thin plates 1a, 1b are brought into contact with the beaded thin plates 1a, 1b on the outer peripheral edge of the intermediate plate structure 6. They are stacked, and have a ring shape corresponding to the shape of the fluid passage hole 2. The reason why the middle plate structure is circular is that it is easy to manufacture and secures accuracy,
This is because it can be manufactured at low cost with low material cost.

In FIG. 3 showing the second embodiment, not only the folded edges 4a and 4b are folded but also strongly compressed to 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 configuration is the same as that of the first embodiment, the description is omitted.

In FIG. 4 showing the third embodiment, the folded edge 4a is formed only on the beaded thin plate 1a, and the amount of compression of the bead portions 3a, 3b and the middle plate structure 6 is adjusted. The other configuration is the same as that of the first embodiment, and the description is omitted.

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

[0016]

According to the metal-laminated gasket according to the present invention described above, when the gasket is compressed by turning the periphery of one or both fluid passage holes of the pair of beaded thin plates inward. The folded portion acts as a stopper, and while the bead portion formed on the outer diameter portion and the middle plate structure sandwiched in contact with the bead portion in a high temperature state, the compression restoring property at the time of high temperature is ensured, The bead portion of one beaded thin plate and the beaded portion of the other beaded portion have different radii at the formation positions, and ceramic or heat-resistant alloy steel is used as the intermediate plate structure, and the inside and outside of the intermediate plate structure are used. By laminating the beaded thin plate on the peripheral edge 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 the 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 line AA of FIG.

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

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

[Explanation of symbols]

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

Claims (2)

(57) [Claims] 1. A pair of beaded thin plates 1 made of a metal material having excellent heat resistance and formed with inwardly protruding bead portions 3a and 3b around an opened fluid passage hole 2.
a, 1b, an intermediate plate 5 laminated between the thin plates with beads except for the periphery of the fluid passage hole 2, and a ring-shaped intermediate plate structure 6 laminated between the peripheral edges of the fluid passage hole 2. Of the pair of beaded thin plates 1a and 1b, the periphery of one or both fluid passage holes 2 is folded inward to form a bead portion 3a of one beaded thin plate 1a.
And the radius of the formation position of the bead portion 3b of the other beaded thin plate 1b is varied in size, and ceramics or heat-resistant alloy steel is used as the intermediate plate structure 6, and the inner peripheral portion of the intermediate plate structure 6 A metal-laminated gasket, wherein beads 3a and 3b of beaded thin plates 1a and 1b are laminated in a contact state. 2. The metal laminate gasket according to claim 1, wherein the intermediate plate structure 6 is formed of a plurality of laminates.