Nippon Gasket Company, Ltd.

Toyota Jidosha Kabushiki Kaisha

Masahiko Miura

Kunitoshi Inoue

Kazukuni Takada

Hiroshi Uemura

Yoshikazu Shinpo

Kenji Kubouchi

Kazuya Nakata

Shigeru Kawaguchi

Tadayoshi Akutsu

Hideo Yamamoto

Kazuya Yoshijima

Kiyoshi Sugimoto

Kazuaki Sugimura

Kazuyuki Geshi

Hitoshi Shimamura

Ken Ohkura

Tetsuhiro Hosokawa

Michio Katoh

A metal gasket is described which has a structure with no beads so that the need for dies used for molding is eliminated, thereby facilitating the processing of the gasket and achieving good cost performance, and which is excellent in sealing ability. The metal gasket comprises (i) an elastic metal plate having a base and folded-back portions each of which is formed so as to create a clearance together with the base and disposed so as to extend around a bore hole and (ii) a metal plate which is thicker than the elastic metal plate and has lower level portions each of which is located at a position closed to each bore hole, and the elastic metal plate and the metal plate are laminated such that each folded-back portion of the elastic metal plate faces the lower level portion of the metal plate.

Metal gasket

This metal gasket is formed by interposing a shim member between a pair of elastic metal plates, and fixing the shim member and one of the elastic metal plate to each other at the portions thereof which are opposed to a water jacket, whereby the function of the shim member is secured with the fixed portions and opposed surfaces not interfering with each other. The shim member comprises a shim member body corresponding to an end surface of a cylinder body of a cylinder block, and projecting portions integral with said shim member body and extending therefrom to a position opposed to the water jacket. The fixing portions at which the shim member and one elastic metal plate are fixed to each other by crimping are positioned on the projecting portions extending to positions opposed to the water jacket. Therefore, when the metal gasket is tightened between the cylinder block and a cylinder head, the fixed portions do not interfere with the opposed surfaces thereof including end surfaces, and the sealing function of the metal gasket is not spoiled.

The present invention comprises a pair of bead plates on which beads are formed, and an intermediate plate on which first and second stepped portions are formed. One of the bead plates is provided with auxiliary beads so as to prevent a full compression of the beads and increase the sealability. This metal gasket comprises first and second bead plates having beads and extending along the circumferences of holes, and an intermediate plate interposed between the bead plates. The intermediate plate is provided in the regions thereof which extend along the circumferences of the holes and on the inner side of the beads with first stepped portions extending toward the first bead plate, and second stepped portions extending toward the second bead plate. The second bead plate is provided with auxiliary beads extending toward the second stepped portions. The auxiliary beads are adapted to engage the intermediate plate to increase the surface pressure and prevent the leakage of a high-temperature gas toward the beads on the first and second bead plates and the permanent set in fatigue of wing parts of the second stepped portions of the intermediate plate.

In this metal gasket, the beads formed on an intermediate plate prevent a full compression of bead plates and improve the sealability of the gasket. This metal gasket comprises first and second bead plates having main beads extending along the circumferences of holes, and an intermediate plate interposed between the first and second bead plates. The intermediate plate is provided in the regions thereof which are between the holes and the main bead-contacting portions thereof with beads opposed to the first bead plate, and these beads form compensating portions for the first bead plate. The second bead plate is provided with auxiliary beads having projecting portions engageable with the recessed portions of the beads on the intermediate plate. The compensating portions mentioned above prevent a full compression of the beads on the bead plates when the metal gasket is tightened, and offset the irregularity of the opposed surfaces of a cylinder head and a cylinder block. The auxiliary beads improve the sealability of the second bead plate with respect to the compensating portion-carrying intermediate plate.

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.

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

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

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.

Metallic gasket

Disclosed is a metal gasket for a manifold produced by laminating a plurality of bead plates having bead portions which are bent at a predetermined radius of curvature R and by setting the ratio R/t of the radius of curvature R to the thickness t of the bead plates to the range of 7 to 15. Therefore, the radius of curvature of the bent portions of the bead plates to the thickness can be made relatively great and the bent portions of the bead plates become smooth. As a result, when the metal gasket is tightened between a cylinder head and an exhaust manifold, the contact portions of the bead plates are expanded and the stress and face-to-face pressure occurring at the contact portions can be reduced. Accordingly, the stress acting on the bead plates can be made lower than a reference value, the increase of the facet-face pressure can be restricted to within a predetermined range and the stress and face-to-face pressure of the bead portions forming a seal surface can be kept within suitable ranges. For these reasons, even if great thermal deformation occurs in the exhaust manifold relative to the cylinder head, seal performance of the metal gasket is not lowered.

Growing community of inventors

Kawachinagano, Japan

Masahiko Miura