Japan Metal Gasket Co., Ltd.

Nihon Metal Gasket Co., Ltd.

Nihon Metal Gasket Kabushiki Kaisha

Kosaku Ueta

Hideo Watanabe

Ikkoh Ueta

Kazuya Yoshijima

Yukio Kawai

Takeshi Kitamura

Nobuhide Kobayashi

Jun Okano

Masahiko Nakada

A metallic gasket including a base plate having a convex metal bead formed, by bending the base plate, between a combustion chamber opening and on the outer periphery portion of the base plate, and a first thickness-increased portion formed thicker than the remaining portions of the base plate to provide a difference in thickness, by which a surface pressure is made to concentrate on the first thickness-increased portion to seal a joint between a cylinder head and a cylinder block when the metallic gasket is disposed between the joint surfaces of the cylinder head and the cylinder block and fastened by clamping bolts. An elastic sealing material is fixed to the convex portion of the metal bead and filled in a concave portion on the reverse side of the base plate to form a rubber bead, and the sealing material is deformed under compression in the through-thickness direction in cooperation with the deformation of the metal bead when the gasket is fastened with clamping bolts. This gasket reduces production cost and preserves a stable sealing performance for extended periods of time.

Metallic gasket

Provided is a connecting structure in which it is difficult for a crack to occur, even if a connection location is set in a portion on which concentrated tensile stress may occur. Laminated metal plates are concurrently punched out downward in shape of tongue piece. A depth of punch-out is not smaller than a total thickness of the laminated metal plates. A tongue piece portion is punched out in shape of cantilever beam while a central connection portion is left behind. The tongue piece portion is bent downward in the out-of-plane direction at a connection portion linking to the central connection portion in order that a location of the tongue piece portion in the extension direction on its way is parallel to a bend line. The tongue piece portion is configured to widen in width gradually toward a front end thereof.

Connecting structure of metal plates

A gasket which can uniformize the facial pressure on the thickened part more securely is to be provided. A gasket comprises a pair of base plates and stacked above and underneath, in which combustion chamber holes and bolt holes are bored, a doubling plate and shim plates intervene between these base plates. On this doubling plate, a second bead, which permits plastic deformation, extends in the circumferential direction of each combustion chamber hole. As the second bead is deformed according to the magnitude of the fastening load, the gasket height lowers where the fastening load is heavy and the facial pressure on the peripheries of combustion chamber holes is uniformized after fastening.

Gasket

A gasket which can secure a sufficient sealing capability even for compact, light and less rigid high-performance engines is to be provided. The gasket comprises a metallic base plate and a shim plate stacked around each of combustion chamber holes in the base plate. A base plate bead consisting of a full bead is formed along the circumference of each of the combustion chamber holes. The shim plate is large enough to be arranged opposite a first flat part, a base plate bead formation position A and a second flat part in the base plate. A plurality of strips of auxiliary beads are formed in the part of the shim plate opposite the base plate.

A metallic gasket having a first seal line SLarranged in a manner to encircle the peripheral edge of an exhaust gas hole, a second seal line SLarranged along the outer peripheral edge of a base plate, and full beadsformed each in a convex cross-section by bending the base platealong both seal lines. Elastic sealing materialto, the height of which is substantially equal to the height of a convex portion of the beads, are fixed to the convex portion and a flat surface continuous to the convex portion. The elastic sealing material on the flat surface is so arranged as to cover up to the opening mouth position of the exhaust gas holeor a peripheral edge position of the base plateand, furthermore, elastic material partsare filled in a concave portion of the bead on the reverse side of the convex portion. This structure of the gasket leads to cost reduction and enables the gasket to maintain a stable sealing performance for a long period of time.

A metallic gasket comprising a base plate having a first thickness-increased portionformed at a peripheral edge on a combustion chamber openingside of a base plate, and a first seal line SLand a second seal line SLarranged on the outer side of said first thickness-increased portionNo openings other than a cooling water holeexist between said two seal lines. Beads formed along said seal lines SLand SLeach consist of a convex metal bead raised only upward from an upper surface of said base plate and a rubber bead made of an elastic sealing material fixed to a convex portion and a concave portion of said metal bead. This structure of said metallic gasket can improve a processing accuracy of said metal bead and also enhance cooling effects on said metallic gasket itself and said joint surfaces of an engine, between which said metallic gasket is disposed.

Metal gasket

A metallic gasket capable of providing a sufficient sealing capability all around a combustion chamber hole and avoiding such problems that the step of a cylinder block supporting the lower end part of a cast-iron sleeve is damaged by the thermal expansion of the sleeve during the operation, the roundness of a bore is impaired, the cast-iron sleeve is sunk, and a pressure leaks between the fastening bolts, wherein the end part of a shim plate ( ) on a combustion chamber hole ( ) side is disposed on the upper end surface of the cast-iron sleeve ( ) radially outside the outer peripheral position (OL ), the end part of the shim plate ( ) more distant from the combustion chamber hole ( ) is disposed on the combustion chamber hole ( ) side from an outside line (OL ) of the water jacket ( ) formed in the cylinder block ( ), and a part of a full bead ( ) is disposed on the upper end surface of the cast-iron sleeve ( ).

Method for connecting laminated metal plates and press mold

An edge of a cylinder bore hole of a base plate is folded back on the base plate to form a double-layer folded portion, and a soft member is held in the inside of the folded portion. Folded portions are also formed by folding an outer peripheral edge of the base plate at positions along a straight line which passes through center points of bolt holes which are located at each side of a reference line passing through center points of cylinder bore holes. The straight line is parallel with the reference line. Further folded portions are formed by folding the outer peripheral edge of the base plate at positions along a further straight line which passes through center points of bolt holes which are located at both sides of the reference line so that the further straight line is orthogonal to the the reference line. Rubber beads made of silicon rubber are formed on both joining surfaces of the base plate to bound each of the cylinder bore holes and the bolt holes.

In a metallic gasket in which a plate member having at least one flexible metal plate has a hole, a flat portion formed at the periphery of the hole and a bead disposed concentrically with the hole to the outside of the flat portion is sandwiched between joining faces, an annular stopper is secured to the plate member at a position corresponding to the flat portion on the side of the hole. The stopper is made of a metal material different from the plate member and formed to an increased thickness at a portion for a larger gap, and formed to a decreased thickness at a portion for a smaller gap depending on the difference of the size of the gap between the joining faces.

A metallic gasket includes two base plates and a subplate interposed between the base plates, and cylinder bore holes are formed respectively in the base plates and the subplate concentrically. Beads are respectively formed on the base plates circumferentially along a periphery of the cylinder bore hole. An inner edge of the subplate facing the cylinder bore hole is folded back to form a folded section having two layers, and a starting point of a substantially round-shaped folded end portion of the folded section of the subplate is positioned on a line perpendicular to a surface of the gasket, which line passes through ends of the base plates defining the cylinder bore hole, or the starting point of the folded end portion of the folded section of the subplate is positioned slightly at an inside towards the cylinder bore hole beyond the ends of the ends of the base plates. As a result, the folded end portion of the subplate protrudes beyond the ends of the base plates.

Metallic gasket with inwardly projecting folded end portion

A metallic gasket includes two elastic metal base plates and a thinner subplate disposed between the inner sides of the base plates, wherein at least two cylinder bore holes are perforated in each of the base plates and subplate, a bead protrudes outward from each base plate at the periphery of each cylinder bore hole by way of a flat area, and a linear bead joining the beads for both of the adjacent cylinder bore holes is formed between the adjacent cylinder bore holes. The subplate includes an essentially circular circumferential edge portion present only at the periphery of each of the cylinder bore holes and a continuous portion between adjacent cylinder bore holes. The subplate is secured to the circumference at the inner side of one of the base plates at a portion of the flat area of the base plate near the cylinder bore hole, the outer circumferential end at the peripheral edge of the subplate is varied within the bead width of the base plate and a linear bead that can be contained within the linear base plate bead is formed only in the continuous portion of the subplate.

Growing community of inventors

Kumagaya, Japan

Kosaku Ueta