JP2905754B2 - 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 which is interposed between a cylinder block and a cylinder head which are fastened to each other by a tightening bolt to prevent leakage of combustion gas between the block and the head.

[0002]

2. Description of the Related Art Various types of laminated metal gaskets for use in an internal combustion engine have been proposed without mentioning specific examples. Of these, a gasket motherboard has a pair of first and second plates. There is a structure in which a material is formed, a first plate is folded toward the second plate, and a folded portion is formed to form a cylinder hole, and a metal ring surrounding the cylinder hole is provided in the folded portion.

[0003]

In the above-mentioned prior art, a metal ring is housed in a folded portion, and the folded portion is relatively thicker than other portions to generate a sealing surface pressure, so that a gasket inherent in the gasket is formed. The metal ring is designed to have the same width over the entire circumference, so that the metal ring has the same width over the entire circumference. It receives a strong load, inevitably generates more seal surface pressure than necessary, and the other parts decrease the seal surface pressure by that much, and the surface pressure distribution as a whole lacks equilibrium,
This is a cause of combustion gas leakage.

The present invention has been made as one of the means for solving such problems.

[0005]

A first plate of a gasket base material composed of a first plate and a second plate is folded back on the second plate side so as not to overlap with the second plate to form a cylinder hole. A metal ring surrounding the cylinder hole is interposed between the folded piece of the folded portion and the first plate, and the folded portion is positioned closer to the bolt hole than other portions of the metal ring. The basic means is that a wider projecting portion is interposed between the first and second plates.

[0006] By providing a bead surrounding the metal ring on the second plate, the bead can perform a secondary sealing function, thereby providing a metal laminated gasket that performs more reliable gas sealing.

[0007]

1 shows an embodiment of a metal laminated gasket according to the present invention. FIG. 1 is a partially cutaway front view, FIG. 2 is a sectional view taken along the line a--a of FIG. 1, and FIG. It is bb sectional drawing.

Reference numeral 1 denotes a first plate constituting the gasket base material A. Reference numeral 2 denotes a second plate which is superposed on the first plate 1 to constitute the gasket base material A. On the side, and the second plate 2
A folded portion 4 is formed so as to form a cylinder hole 3 by being folded so as not to overlap with a metal ring 6 surrounding the cylinder hole 3 between a folded piece 5 constituting the folded portion 4 and the first plate 1. Is interposed.

The metal ring 6 comprises a wide portion 6a and a narrow portion 6b, and the wide portion 6a is formed in the bolt hole 7 provided in the gasket base material A (first and second plates 1, 2) by the narrow width. The metal ring 6 is arranged closer to the portion 6b, and the portion of the wide portion 6a protruding from the folded portion 4 is interposed between the first plate 1 and the second plate 2 to surround the metal ring 6. A bead 8 is provided on the second plate 2.

In the embodiment, the wide portion referred to in the present invention refers to a portion that protrudes from the folded portion 4 and is interposed between the first and second plates 1 and 2 and has a shape (planar surface). ) Need not be limited to that of the embodiment.

The second plate 2 has a metal ring 6
As a result of the occurrence of a portion (for example, FIG. 1) that does not overlap with a portion (for example, FIG. 2), a so-called step occurs at the boundary between these portions, but the existence of this step restricts the rotation of the metal ring 6. The ring 6 is maintained at a fixed position, and the high surface pressure portion near the bolt hole is separated from the peripheral edge of the cylinder hole, thereby preventing the peripheral edge of the cylinder hole from being deformed.

[0012]

The present invention has the configuration described above,
The tightening load in the vicinity of the tightening bolt hole can be prevented from deforming the peripheral edge of the cylinder hole on the engine side due to concentration on the stepped portion away from the cylinder hole, and the above-mentioned tightening load is dispersed as it is, providing a well-balanced surface pressure distribution. Gaskets can be provided.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view.

FIG. 2 is a sectional view taken along line aa of FIG.

FIG. 3 is a sectional view taken along line bb of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st plate 2 2nd plate 3 Cylinder hole 4 Folding part 5 Folding piece 6 Metal ring

Claims (2)

(57) [Claims] A first plate of a gasket base material comprising a first plate and a second plate is provided on a side of the second plate so as to be folded so as not to overlap with the second plate, thereby forming a folded portion forming a cylinder hole; A metal ring surrounding the cylinder hole was interposed between the folded piece of the folded portion and the first plate, and protruded from the folded portion closer to the bolt hole than the other portion of the metal ring. A laminated metal gasket having a wide portion interposed between the first and second plates. 2. The gasket according to claim 1, wherein a bead surrounding the metal ring is provided on the second plate.