A multi-layered metal sheet is disclosed formed of a laminate of a plurality of metal sheets fixed to each other by a clinch formed in a concave shape from one main surface toward another main surface, the clinch has an schematic pillar shape, the clinch being defined by an open top, a pair of cut surfaces which are respectively formed from the open top toward a bottom, a pair of inclined surfaces respectively inclined from the open top toward the bottom, transitional surfaces which connect the cut surfaces and the inclined surfaces to each other, and the bottom having overlapping parts which extend over the main surface of the multi-layered metal sheet on a lower side immediately below the cut surfaces, and lengthwise end portions of a cut formed in each of upper edge portions of the cut surfaces are disposed on upper edge portions of the transitional surfaces.

It is an object of the present invention to provide a sealing structure for a casing that can reduce the number of used gaskets and achieve further weight reduction, with the sealing function of the gaskets secured. The object is solved by including: a case 2 having an opened top; a cover 3 attached to the top of the case 2 to form a fluid flow path therein; a center plate 5 interposed between the case 2 and the cover 3 and partitions an inner space into the side of the case 2 and the side of the cover 3; and a gasket 4, which is disposed between the case 2 and the cover 3, and forming the center plate 5 so as to have a size that is within an inner peripheral side relative to a sealing line 41 of the gasket 4 and stacking this center plate on the gasket 4, and attaching the cover 3 to the top of the case 2 with the stacked gasket 4 and center plate 5 sandwiched there between to compress the gasket 4 with the mutual butting surfaces between the case 2 and the cover 3.

A layered head gasket includes a gasket core, a head-layer, a block-layer, and a plurality of apertures. The head gasket may be useful for sealing an internal combustion engine having a cylinder head, a cylinder block, a plurality of combustion chamber passageways, a plurality of coolant passageways, and a plurality of oil passageways. The gasket core is made of a copper sheet. The head-layer may be made of spring steel and may be fixed to a top side of the gasket core, being configured to interface with the cylinder head. Likewise, the block-layer may be made of spring steel and may be fixed to a bottom side of the gasket core, being configured to interface with the cylinder block. The plurality of apertures may pass through the head-layer, the gasket core, and the block-layer.

A multi-layered metal sheet is disclosed formed of a laminate of a plurality of metal sheets fixed to each other by a clinch formed in a concave shape from one main surface toward another main surface, the clinch has an schematic pillar shape, the clinch being defined by an open top, a pair of cut surfaces which are respectively formed from the open top toward a bottom, a pair of inclined surfaces respectively inclined from the open top toward the bottom, transitional surfaces which connect the cut surfaces and the inclined surfaces to each other, and the bottom having overlapping parts which extend over the main surface of the multi-layered metal sheet on a lower side immediately below the cut surfaces, and lengthwise end portions of a cut formed in each of upper edge portions of the cut surfaces are disposed on upper edge portions of the transitional surfaces.

An object of the present invention is to provide a gasket capable of improving sealing performance by solving a non-uniform surface pressure distribution by a grommet structure. Provided is a gasket which is formed by laminating an upper layer, an intermediate layer, and a lower layer and is provided with a penetration hole and a seal bead formed at the upper layer and the lower layer to surround the penetration hole in a ring shape and to be symmetrical with respect to the intermediate layer in the vertical direction, in which the intermediate layer includes a fold-back portion, a surface pressure adjustment portion, and a bead contact portion, a plate thickness of the fold-back portion is thicker than that of the bead contact portion, and the surface pressure adjustment portion sets an upper step to be different from a lower step.

It is an object of the present invention to provide a sealing structure for a casing that can reduce the number of used gaskets and achieve further weight reduction, with the sealing function of the gaskets secured. The object is solved by including: a case 2 having an opened top; a cover 3 attached to the top of the case 2 to form a fluid flow path therein; a center plate 5 interposed between the case 2 and the cover 3 and partitions an inner space into the side of the case 2 and the side of the cover 3; and a gasket 4, which is disposed between the case 2 and the cover 3, and forming the center plate 5 so as to have a size that is within an inner peripheral side relative to a sealing line 41 of the gasket 4 and stacking this center plate on the gasket 4, and attaching the cover 3 to the top of the case 2 with the stacked gasket 4 and center plate 5 sandwiched there between to compress the gasket 4 with the mutual butting surfaces between the case 2 and the cover 3.

An internal combustion engine gasket includes a plurality of annular plates that are stacked. Each of the annular plates includes: a through-hole; an inner circumferential portion; a plurality of bolt holes; an outer circumferential portion; and an intermediate portion. The annular plates includes: a grommet plate having a fold-back portion in the inner circumferential portion; and first and second seal plates stacked on both sides of the grommet plate, and having a bead in the intermediate portion. The inner circumferential portion of the first seal plate is wrapped or held by the fold-back portion of the grommet plate. A spacer member is formed between the grommet plate and the first or second seal plate along the entire circumference of the outer circumferential portion so as to have a thickness smaller than or equal to the grommet plate and include all of the bolt holes.

A gasket capable of surely preventing leakage of a fluid, without deteriorating a sealing performance even when a situation of fall of surface pressure at a periphery edge of a through hole occurs is provided. There are formed a primary seal structure 31a lying on an inner side in the radial direction of a periphery edge end 29a and a secondary seal structure 32a lying on an outer side in the radial direction of the periphery edge end 29a, in which the primary seal structure 31a includes a primary upper layer bead 33a formed to an upper layer 21, a primary intermediate layer bead 34a formed to a second plate material 28 of an intermediate layer 22 and a primary lower layer bead 35a formed to a lower layer 23 stacked in an x direction, and the secondary seal structure 32a includes a secondary upper layer bead 36a formed to the upper layer 21, an secondary intermediate layer bead 37a formed to the second plate material 28 of the intermediate layer 22 and a secondary lower layer bead 38a formed to the lower layer 23 stacked in the x direction.

An object of the present invention is to provide a gasket capable of improving sealing performance by solving a non-uniform surface pressure distribution by a grommet structure. Provided is a gasket which is formed by laminating an upper layer, an intermediate layer, and a lower layer and is provided with a penetration hole and a seal bead formed at the upper layer and the lower layer to surround the penetration hole in a ring shape and to be symmetrical with respect to the intermediate layer in the vertical direction, in which the intermediate layer includes a fold-back portion, a surface pressure adjustment portion, and a bead contact portion, a plate thickness of the fold-back portion is thicker than that of the bead contact portion, and the surface pressure adjustment portion sets an upper step to be different from a lower step.

A gasket for providing a gas and fluid tight between parts of an internal combustion engine, for example around a combustion chamber opening, is provided. The gasket includes a functional layer with a full embossment spaced from the combustion chamber opening. A stopper layer is attached to the functional layer adjacent the combustion chamber opening. After attaching the stopper layer to the functional layer, half embossments are simultaneously formed in the functional layer and the stopper layer adjacent the combustion chamber opening. The aligned half embossments are together referred to as a half-stop. The half-stop maintains the load on the stopper layer, limits compression on the full embossment, and protects the full embossment from combustion gases when the gasket is compressed between two parts of the internal combustion engine.