Abstract: A laminated-type metal gasket material plate includes a metal plate having two sides, a rubber layer, a layer of a surface preparation agent free from hexavalent chromium, and an adhesive layer. The layer of the surface preparation agent is coated on at least one side of the plate. The adhesive layer attaches the rubber layer and is provided on the layer of the surface preparation agent. Both the adhesive layer and the rubber layer contain a rust-resistant pigment.

Abstract: The present invention is intended to provide a metal gasket material plate with which exfoliation of the coating or blister can be prevented even if it is used in the presence of an electrolyte aqueous solution and which can be manufactured through a process without use of hexavalent chromium in consideration of the environment, etc. The present, invention relates to a metal gasket material plate comprising a metal plate 1 having a rubber layer 4 on one side or both sides thereof through an adhesive layer 3, wherein a rust-resistant pigment is added to both of said adhesive layer 3 and said rubber layer 4.

Abstract: A metal gasket for a cylinder head has a lamination of plates. The gasket includes two base metal plates each of which includes cylinder holes, circumferential beads formed around the peripheries of individual cylinder holes, cooling water holes formed outside the peripheries of the circumferential beads, and an outer bead formed so as to entirely enclose the circumferential beads and the cooling water holes. The circumferential beads of the two base plates are aligned in a direction of thickness of the gasket. Claw shaped protrusions are provided for one of an outer step adjustment metal plate and an inner step adjustment metal plate and extend from a cooling water jacket to the outer edges of the base plates into engagement holes in the other of the inner step adjustment plate and the outer step adjustment plate.

Abstract: (Problems to be Solved) The present invention is intended to provide a metal gasket material plate with which exfoliation of the coating or blister can be prevented even if it is used in the presence of an electrolyte aqueous solution and which can be manufactured through a process without use of hexavalent chromium in consideration of the environment, etc. (Means for Solving the Problems) The present, invention relates to a metal gasket material plate comprising a metal plate 1 having a rubber layer 4 on one side or both sides thereof through an adhesive layer 3, wherein a rust-resistant pigment is added to both of said adhesive layer 3 and said rubber layer 4.

Abstract: A metal gasket for cylinder head 1 of plate lamination type, comprises two base metal plates each of which includes cylinder holes, circumferential beads formed around the peripheries of individual cylinder holes, cooling water holes formed outside the peripheries of the circumferential beads, and an outer bead formed and positioned so as to entirely enclose the circumferential beads and the cooling water holes, wherein the circumferential beads of the two base plates are aligned in the direction of thickness of the metal gasket. Claw-like protrusions are provided for one of an outer step adjustment metal plate and extending from the cooling water jacket to the outer edges of the base plates, and a thicker inner step adjustment metal plate 4 extending from inside the circumferential beads to the cooling water jacket, into engagement holes in the other of the inner step adjustment plate and the outer step adjustment plate.

Abstract: A method of producing a metal gasket includes steps of alkaline cleaning a metal plate, coating a non-rinse chemical for chromate conversion of surfaces of the metal plate and drying to form chromate films, coating an adhesive on the chromate films and drying or baking the adhesive to form adhesive layers, and coating a rubber compound of a sheet-like or an amorphous mixed compound to a predetermined thickness on the adhesive layers and heating and vulcanizing the rubber compound to form rubber coated metal plate. A metal gasket manufactured in this manner has a high bonding power of the rubber layers to the metal plate to obtain an improved durability for long use.

Abstract: A method of producing a metal gasket having at least a cooling water opening comprises steps of coating a surface treatment agent on an outer surface of the metal gasket, covering by a masking jig the outer surface of the metal gasket except a region surrounding the cooling water opening, and removing the surface treatment agent in the region by jetting superhigh pressure water at the region.

Abstract: A metal gasket for an internal combustion engine has cylinder openings and a cooling water openings and is coated on its outer surface with a surface treatment agent. The surface treatment agent in a region of the metal gasket surrounding the cooling water openings has been removed. A method of producing a metal gasket having at least a cooling water opening comprises steps of coating a surface treatment agent on an outer surface of the metal gasket, covering by a masking jig the outer surface of the metal gasket except a region surrounding the cooling water opening, and removing the surface treatment agent in the region by jetting superhigh pressure water at the region.

Abstract: A metal gasket for a cylinder head of an internal combustion engine comprises at least one narrow portion extending between cylinder bores of the cylinder head to be sealed by the gasket, and beads extending along circumferences of the cylinder bores. The adjacent beads extend in opposite directions with respect to the gasket, thereby enabling the adjacent beads to be smoothly and gently connected. Such smoothly connected beads prevent any cracks or permanent deformations in the proximity of the beads from occuring when the gasket is firmly clamped between the cylinder head and an engine body. Restoring faculty of the gasket is not lost after being clamped therebetween, so that the sealing capacity in the proximities of the beads is remarkably improved in comparison with the prior art.