Nippon Gasket Company, Ltd.

Kunitoshi Inoue

Kenji Kubouchi

Shigeru Kawaguchi

Masahiko Miura

Hiroshi Uemura

Kazukuni Takada

Kenji Ishida

Yuji Fukui

Tadayoshi Akutsu

Hideo Yamamoto

Yoshikazu Shinpo

Kazuya Nakata

Tsuyoshi Hiramatsu

Tomoyoshi Ogaeri

Naoki Ii

Kenichi Sekioka

Hitoshi Shimamura

Kazuhiro Nomoto

Tetsuhiro Hosokawa

Michio Katoh

Ken Ohkura

An engine gasket flattens the surface pressure occurring around holes, prevents the occurrence of impressions in and damage to a cylinder block and a cylinder head, and secures a stable sealing performance. This metal gasket has elastic metal plates and an intermediate metal plate interposed between these elastic metal plates. The elastic metal plates are provided with full beads along the circumferences of the holes so that the ridge portions of the full beads contact the intermediate metal plate. The intermediate plate has, on regions which are between the holes and full beads of the elastic metal plates, half beads extending toward the elastic metal plates. The elastic metal plates are folded back along the circumferences of the holes.

Metal gasket

In this metal gasket, the stopper plate stacked on the bead base plates has its reduced thickness portionwhose thickness is smaller than the thickness of the stopper plate body-folded back to form a stopper portion. This structure provides the stopper portion with a limited stopper function with fewer parts. Between a pair of bead base plates that seal around the bore holes of the metal gasket is clamped an intermediate plate as the stopper plate. Around the bore holes in the intermediate plate are arranged folded portions, whose total thickness is larger than the thickness of the stopper plate body, to restrict the deformation of the beads. The folded portions are formed by folding back fold parts onto base parts that are thinner than the stopper plate body. This structure can limit the step height (stopper height) of the intermediate plate without using other parts such as metal plates or stopper pieces.

The metal gasket according to the present invention is formed by bead base plates comprising elastic metal plates having beads and auxiliary beads along the circumferences of holes, and an intermediate plate interposed between these bead base plates. The stoppers and stepped portions formed on the intermediate plate prevent the total compression of the beads on the bead base plates when the metal gasket is tightened, and enable the irregularity of the opposed surfaces of a cylinder head and a cylinder block to be offset. The auxiliary beads provided on the bead base plates display the sealing performance with respect to the beads and minimize the dead spaces around the holes.

A metal gasket comprising an elastic metal plate including beads formed around cylinder bore holes of a multiple-cylinder engine, wherein each bead comprises an independent bead formed around each hole, a common bead between an adjacent pair of holes and junction beads connecting the independent bead and the common bead. The metal gasket controls a spring constant at the junction beads to a suitable value by specifying the shape of the junction beads, reduces a peak value of a face-to-face pressure at the junction beads, reduces also drop of the face-to-face pressure occurring in the junction beads and at their boundary, and makes uniform the face-to-face pressure in the vicinity of the junction beads.

This metal gasket comprises a pair of bead plates on which beads are formed so as to extend along the circumferences of combustion chamber holes, and an intermediate plate interposed between the bead plates. The intermediate plate is provided on the parts thereof which are closer to the combustion chamber holes than to the beads on the bead plates with stopper portions comprising stepped portions. These stopper portions constitute compensation portions for the beads on the bead plates. The compensation portions prevent a total compression of the beads on the bead plates when the metal gasket is tightened, offset the irregularity of opposed surfaces of a cylinder head and a cylinder block, improve the sealability with respect to the beads, and protect the beads against corrosion and compression.

Metal gasket with stepped intermediate plate

A metal gasket for a cylinder head includes a superposed assembly of an elastic metal base plate having a plurality of beads formed along a plurality of juxtaposed holes for combustion chambers, an elastic metal adjusting plate having a plurality of beads formed along a plurality of juxtaposed holes for combustion chambers, and a grommet having a plurality of juxtaposed holes for combustion chambers which are smaller in diameter than the holes in the base and adjusting plates. The grommet is folded about the edges of the holes in the adjusting plate lying between the base plate and the grommet in intimate contact therewith, so that the holes in the base and adjusting plates and the grommet may be aligned to form a plurality of bores. The bead on the base plate is formed as a full bead between every two adjoining holes and as a half bead around the remaining edge of each hole, while the bead on the adjusting plate is a full bead along the entire edge of each hole, so that the bead on the base plate may extend over the bead on the adjusting plate between every two adjoining bores.

Laminated metal gasket having a varying bead structure, thickness, and

This metal gasket is formed by laminating a pair of bead plates and a pair of intermediate plates, and capable of setting the temperature distribution thereof uniform by efficiently cooling high-temperature regions which are in the vicinity of swirl chambers without causing a decrease in the rigidity and strength thereof. The portions of the bead plates which are in the vicinity of the parts thereof in which the swirl chambers are positioned are provided with coolant-contact areas surrounded by half beads formed on the bead plates, these coolant-contact areas being provided with holes. The wall surfaces of these holes directly contact the cooling water flowing in a water jacket in a cylinder head, and fulfil the function of radiating the heat transmitted from a high-temperature combustion gas thereto.

Metal gasket with coolant contact areas

This metal gasket for chain case-carrying engines is capable of reliably preventing the entry of an oil into height different parts, which occur on abutting surfaces of a cylinder block and a chain case, even when the oil deposited on the chain case scatters during a movement of a chain, and improving the reliability thereof owing to its durability. This metal gasket has first and second elastic metal plates provided with beads extending along an opening, in which the chain moves, and an intermediate plate provided with bores packed with seal members for sealing the height different parts occurring at the abutting surfaces of the chain case and cylinder block. The second elastic metal plate is provided with recesses formed by cutting out the portions thereof in which the seal members are positioned.

Metal gasket for chain case-carrying engines

A metal gasket comprising an elastic metal plate including beads formed around cylinder bore holes of a multiple-cylinder engine, wherein each bead comprises an independent bead formed around each hole, a common bead between an adjacent pair of holes and junction beads connecting the independent bead and the common bead. The metal gasket controls a spring constant at the junction beads to a suitable value by specifying the shape of the junction beads, reduces a peak value of a face-to-face pressure at the junction beads and makes uniform the face-to-face pressure in the vicinity of the junction beads.

The metallic gasket consists of a first elastic metallic plate having beads and folded portions and a second elastic metallic plate having beads, laminated on each other. The folded portions are formed by bending the plate alone the circumferences of cylinder bore holes, and the beads are formed on the portions of the plate spaced from the circumferences of the cylinder bore holes at a predetermined distance in the radially outward direction thereof, whereby double annular seal portions are formed. The projecting portions of the beads on the second elastic metallic plate are fitted in or brought into contact with the recessed portions or projecting portions of the beads on the first elastic metallic plate. The spring constant of the gasket becomes equal to the sum of those of the two plates, and this enables the stress carried by the plates to be lessened, and the durability of the gasket to be improved. It is also possible to reduce the width of the parts of the beads which are between the cylinder bore holes and use such a gasket suitably for an engine in which the distance between cylinder bores is small.

Metallic gasket

At the portions of the metallic gasket according to the present invention which are around perforations the inner diameter of which is smaller than that of holes for combustion chamber, the thickness of at least the folded portions and the portions of an elastic metallic plate on which these folded portions are laminated are reduced to a level in the range from a level not higher than that of the thickness of said metallic plate to a level not lower than that of a half of the thickness of said metallic plate. These thickness-reduced portions of the metallic plate are bent onto the bead-ridge-carrying side thereof to form folded portions, whereby the thickness of the folded portions is reduced to provide a difference in height between the folded portions and the bead-surrounding portions of the metallic plate. The metallic plate is heat treated after the folding step has been completed, to regulate the hardness of the metallic plate.

Metallic gasket and method of manufacturing the same

This invention provides a metal gasket and its production method which prevents damage to folded portions by fold-machining and damage to metal materials after fastening, and expands the range of selection of materials for elastic metal plates, by reducing the thickness of a predetermined region of a elastic metal plate at which folded portions are to be formed. The thickness of the folded portion of the elastic metal plate is reduced from the folding side in an inner region of folded base portions and in regions in which folded free ends are positioned. Bend-machining is made gently at the folded base portions subjected to fold-bend machining, and the folded base portions each have a gap there-inside. The folded free ends do not come into contact with the elastic metal plate due to recessed surfaces. Accordingly, cracks and wrinkles do not occur at the folded base portions, and the folded free ends do not leave friction traces on the elastic metal plate.

Metal gasket and production method thereof

In the metallic gasket according to the present invention, beads are formed on the circumferential portions of the first cylinder bore-aligned holes in the base member, and folded portions are formed on the auxiliary member by merely folding back the inner edge sections of the second cylinder bore-aligned holes therein so as not to embrace the bead-carrying base member, the auxiliary member being laminated on the side of the base member from which the beads project. In this metallic gasket, the folded portions of the auxiliary member restrict the deformation of the beads to minimize the occurrence of fatigue and cracks in the beads, whereby the sealing function of the gasket is improved with uniform and proper surface pressure distribution maintained. Soft members are provided between the main portion of the auxiliary member and the folded portions thereof so as to secure proper surface pressure distribution in the metallic gasket in accordance with the rigidity of the cylinder head.

This metal gasket interposes a regulation plate having compression stop portions and beads between first and second elastic metal plates the convexities of beads of which face one another. The compression stop portions prevent complete compression of each bead and absorbs any irregularity between opposed fitting surfaces around holes for a combustion chamber. An intermediate plate having an offset portion is sandwiched between the regulation plate and the second elastic metal plate. The offset portion is shaped to a height smaller than the thickness of the compression stop portions and regulates the degree of compression of each bead.

A structure for finding wrong assemblage of the metallic laminate type gasket according to the present invention is composed of a plurality of component sheets overlapping each other, in which small holes for finding wrong assemblage in number one less than the number of sheets to be laminated are bored on each sheet at a part so that, unless any one of the sheets is absent, the small holes are prevented from joining in line like one through hole, whereby whether lamination of the sheets is as complete as designed or not can be confirmed and, when any one of the sheets is absent and small holes join in line like one through hole to pierce through all sheets, wrong assemblage can be confirmed by mechanical or electrical means.

Growing community of inventors

Higashiosaka, Japan

Kunitoshi Inoue