Gasket
AssigneeIshikawa Gasket Co., Ltd.
InventorToshihiro Imai
Life of this patent
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Abstract
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.
Claims9
A gasket comprising three layers of an upper layer, an intermediate layer, and a lower layer laminating together from up to down, and including penetration holes penetrating the three layers and seal beads formed in the upper layer and the lower layer to surround the penetration holes in a ring shape and arranged symmetrical with respect to the intermediate layer in a vertical direction,
- wherein the intermediate layer is formed of at least two plate materials and includes a fold-back portion, a surface pressure adjustment portion, and a bead contact portion sequentially provided outward in a radial direction from a peripheral edge of a penetration hole thereof,
- the fold-back portion is formed in such a manner that a peripheral edge of one plate material in the plate materials is folded back to enclose an end portion on a side of the penetration hole of another plate material and a thickness of the fold-back portion is thicker than that of the bead contact portion,
- all plate materials forming the surface pressure adjustment portion are bent, an upper step is formed by protruding an upper surface of the fold-back portion upward in relation to an upper surface of the bead contact portion, a lower step is formed by protruding a lower surface of the fold-back portion downward in relation to a lower surface of the bead contact portion, and the upper step is set to be different from the lower step, and
- one of the upper step and the lower step where the peripheral edge of the one plate material folded back does not exist is set 1.5 times or more and 1.9 times or less relative to another of the upper step and the lower step.
A gasket comprising three layers of an upper layer, an intermediate layer, and a lower layer laminated together from up to down, and including penetration holes penetrating the three layers and seal beads formed in the upper layer and the lower layer to surround the penetration holes in a ring shape and arranged vertically symmetrical with respect to the intermediate layer,
- wherein the intermediate layer is formed of a first plate material, an intermediate plate material, and a second plate material laminated together from up to down and includes a fold-back portion, a surface pressure adjustment portion, and a bead contact portion sequentially provided outward in a radial direction from a peripheral edge of the penetration hole, and the intermediate plate material exists only at the bead contact portion,
- the fold-back portion is formed in such a manner that a peripheral edge of the first plate material is folded back to enclose an end portion on a side of a penetration hole of the second plate material and a thickness of the fold-back portion is thicker than that of the bead contact portion, and
- in the surface pressure adjustment portion, the first plate material is bent, the second plate material is bent at a bending angle larger than that of the first plate material, an upper step is formed by protruding an upper surface of the fold-back portion in relation to an upper surface of the bead contact portion, and a lower step is formed by protruding a lower surface of the fold-back portion downward in relation to a lower surface of the bead contact portion.
A gasket comprising three layers of an upper layer, an intermediate layer, and a lower layer laminating together from up to down, and including penetration holes penetrating the three layers and seal beads formed in the upper layer and the lower layer to surround the penetration holes in a ring shape and arranged symmetrical with respect to the intermediate layer in a vertical direction,
- wherein the intermediate layer is formed of at least two plate materials and includes a fold-back portion, a surface pressure adjustment portion, and a bead contact portion sequentially provided outward in a radial direction from a peripheral edge of a penetration hole thereof,
- the fold-back portion is formed in such a manner that a peripheral edge of one plate material in the plate materials is folded back to enclose an end portion on a side of the penetration hole of another plate material and a thickness of the fold-back portion is thicker than that of the bead contact portion,
- all plate materials forming the surface pressure adjustment portion are bent, an upper step is formed by protruding an upper surface of the fold-back portion upward in relation to an upper surface of the bead contact portion, a lower step is formed by protruding a lower surface of the fold-back portion downward in relation to a lower surface of the bead contact portion, and the upper step is set to be different from the lower step, and
- one of the upper step and the lower step where the peripheral edge of the one plate material folded back does not exist is set 0.67 times or more and less than another of the upper step and the lower step.
Dependencies are inferred from the claim text.