Toyota Jidosha Kabushiki Kaisha

Taiho Kogyo Co., Ltd.

Nippon Gasket Company, Ltd.

Kazuya Nakata

Yoshikazu Shinpo

Hiroshi Uemura

Masahiko Miura

Kazukuni Takada

Akio Sato

Hirotaka Kakuta

Kazuaki Sugimura

Kenji Uchida

Kunitoshi Inoue

Kenichi Yamaguchi

Kenji Kubouchi

Yukio Kawai

Osamu Jinno

Takeshi Kitamura

Yoshiyuki Hagiwara

Ryosuke Fujiki

Eisaburo Goto

Motoshi Nakamura

Tadayoshi Akutsu

Kazukuni Takata

Takefusa Sasamori

Morihiro Sawada

Masafumi Yamaguchi

Cylinder head gasket

In a method of processing a sealing surface of a casting to eliminate casting defects on or in the vicinity of the sealing surface, each of abrasive grains constituting a grindstone has a flat face formed on its distal end. The sealing surface of the casting is ground by the grindstone while the flat face of each abrasive grain is held parallel to the sealing surface of the casting. Consequently, a plastic flow layer is formed on the sealing surface of the casting. Blowholes present within a predetermined range of depth of the casting from the sealing surface are collapsed as the result of formation of the plastic flow layer.

Method of processing sealing surface of casting and grindstone suitable

This metal gasket comprises a beaded base plate, an intermediate plate and a thin plate, and secures a stable long-standing sealing performance with a face-to-face pressure balance kept properly. This metal gasket is provided with full beads on the beaded base plate, stopper beads on the intermediate plate, and folded portions, which hold the edge portions of bores of the intermediate plate, and full beads, which are laminated on the stopper beads on the intermediate plate, on the thin plate. The folded portions are formed so that they are not laminated on the stopper beads when the metal gasket is in practical use, i.e., when the folded portions are in a compressed condition. The folded portions and stopper beads display a stopper function of preventing the full compression of the full beads on the beaded base plate, and a sealing function of preventing the entry of a combustion gas into the clearances defined by the full beads. The face-to-face pressure occurring on the folded portions, stopper beads and full beads can be controlled properly, and the face-to-face pressure balance can be maintained properly.

Laminated metal gasket for a cylinder block of an engine

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.

Metal gasket

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.

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 having first and second base plates made of metal. In each base plate, at least an opening is defined and a bead is formed around the opening. The second base plate is disposed in parallel with the first base plate with the tip ends of the beads of the first and second base plates facing each other. An annular metallic shim is secured to the first base plate at the side of the bead between the inner periphery of the bead and the opening. And, a resilient sealing member is deposited on the second base plate at the side of the bead around the outer periphery of the bead. A non-vulcanized coating layer of fluoro rubber containing no vulcanizing agent may be deposited on the entire surface of the second base plate at the side of the bead. A vulcanized fluoro rubber may be deposited on the non-vulcanized coating layer at the side of the bead around the outer periphery of the bead.

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Toyota, Japan

Kazuya Nakata