Sealing structure using metal gasket

Abstract

A metal gasket has a primary bead formed on an area positioned between a cylinder bore and a cooling water passage. A second bead is formed on an area corresponding to an opening of one or more cooling passages. A base member of the metal gasket comprises bead plates that have a rubber coating layer. The base member also comprises a shim member disposed between the bead plates. The primary bead is formed by defining a space respectively between the bead plates and the shim member. The secondary bead is formed by defining a space on a given area between the bead plates.

1 . A metal gasket adapted for sealing an interface between a cylinder head and a cylinder body of an engine body, the metal gasket comprising cylinder openings and at least one cooling water passage positioned in the vicinity of at least one of the cylinder openings, the metal gasket further comprising a primary bead that protrudes toward at least one of the cylinder head and the cylinder body, the primary bead being positioned between at least one of the cylinder openings and the at least one cooling water passage, the metal gasket also comprising a secondary bead that protrudes toward at least one of the cylinder head and the cylinder body, the secondary bead being positioned between the primary bead and the at least one cooling water passage such that cooling water is less likely to enter a region defined between the cylinder head and the cylinder body. 
   
   
       2 . The metal gasket of  claim 1 , wherein the secondary bead extends along at least a portion of an edge that defines an opening of the water passage. 
   
   
       3 . The metal gasket of  claim 1 , wherein the engine body is mounted in an outboard motor. 
   
   
       4 . The metal gasket of  claim 1 , wherein a gap filler is applied on at least a part of the secondary bead is formed. 
   
   
       5 . The metal gasket of  claim 4 , wherein the engine body is mounted in an outboard motor. 
   
   
       6 . The metal gasket of  claim 1 , wherein the metal gasket comprises a stainless steel thin-plate base member with a rubber coating layer formed on at least one of its surfaces. 
   
   
       7 . The metal gasket of  claim 6 , wherein the engine body is mounted in an outboard motor. 
   
   
       8 . The metal gasket of  claim 6 , wherein a gap filler is applied on at least a part of the secondary bead is formed. 
   
   
       9 . The metal gasket of  claim 8 , wherein the engine body is mounted in an outboard motor. 
   
   
       10 . The metal gasket of  claim 6 , wherein the base member comprises two bead plates arranged in layers and an inner member disposed between at least a portion of the two bead plates that defines the primary bead, the primary bead being formed by a spaced defined respectively between the two bead plates and the inner member, and the secondary bead being formed by defining a space respectively between the two bead plates and the inner member or between the two bead plates. 
   
   
       11 . The metal gasket of  claim 10 , wherein the engine body is mounted in an outboard motor. 
   
   
       12 . The metal gasket of  claim 10 , wherein a gap filler is applied on at least a part of the secondary bead is formed. 
   
   
       13 . The metal gasket of  claim 12 , wherein the engine body is mounted in an outboard motor.