Method of Manufacturing Metal Gasket

Abstract

Method of manufacturing a metal gasket including a base plate having at least fluid passage holes and circular beads surrounding the fluid passage holes, the base plate being formed by providing a rubber coating layer on a surface of a metal plate with a base coat and an adhesive interposed therebetween. A metal plate having low-temperature age-hardening characteristics is used as the metal plate of the base plate. After the base coat is applied to the metal plate and dried at a temperature lower than a low aging temperature of the metal plate, press-working of the circular beads is performed on the metal plate. Thereafter, the metal plate is age-hardened while burning the base coat at the low aging temperature of the metal plate. A metal gasket having excellent durability and circular beads which are hardly broken even when crushed, is obtained.

1 - 6 . (canceled)  
   
   
       7 . A method of manufacturing a metal gasket including a base plate having at least fluid passage holes and circular beads surrounding the fluid passage holes, the base plate being formed by providing a rubber coating layer on a surface of a metal plate with a base coat and an adhesive interposed therebetween, the method comprising the steps of: 
 by use of a metal plate having low-temperature age-hardening characteristics as the metal plate of said base plate, applying said base coat to the metal plate of said base plate and drying the base coat at a temperature lower than a low aging temperature of the metal plate;    performing press-working of said circular beads on the metal plate; and    age-hardening the metal plate while burning said base coat at the low aging temperature of the metal plate of said base plate.    
   
   
       8 . The method of manufacturing a metal gasket, according to  claim 7 , wherein presetting of the circular beads is performed after the metal plate is age-hardened while burning said base coat at the low aging temperature of the metal plate of said base plate.  
   
   
       9 . The method of manufacturing a metal gasket, according to  claim 7 , wherein 
 said metal gasket further includes an auxiliary plate which is made of a metal plate having no rubber coating layer and has at least fluid passage holes and circular beads surrounding the fluid passage holes,    the metal plate having the low-temperature age-hardening characteristics is used as the metal plate of said auxiliary plate, and    the metal plate is age-hardened at the low aging temperature of the metal plate of said auxiliary plate after press-working of said circular beads on the metal plate of said auxiliary plate.    
   
   
       10 . The method of manufacturing a metal gasket, according to  claim 8 , wherein 
 said metal gasket further includes an auxiliary plate which is made of a metal plate having no rubber coating layer and has at least fluid passage holes and circular beads surrounding the fluid passage holes,    the metal plate having the low-temperature age-hardening characteristics is used as the metal plate of said auxiliary plate, and    the metal plate is age-hardened at the low aging temperature of the metal plate of said auxiliary plate after press-working of said circular beads on the metal plate of said auxiliary plate.    
   
   
       11 . The method of manufacturing a metal gasket, according to  claim 7 , wherein, as conditions of aging treatment for the metal plate having said low-temperature age-hardening characteristics, the temperature is set to not less than 200° C. and less than 250° C., and the length of time is set to 1 to 5 minutes.  
   
   
       12 . The method of manufacturing a metal gasket, according to  claim 8 , wherein, as conditions of aging treatment for the metal plate having said low-temperature age-hardening characteristics, the temperature is set to not less than 200° C. and less than 250° C., and the length of time is set to 1 to 5 minutes.  
   
   
       13 . The method of manufacturing a metal gasket, according to  claim 9 , wherein, as conditions of aging treatment for the metal plate having said low-temperature age-hardening characteristics, the temperature is set to not less than 200° C. and less than 250° C., and the length of time is set to 1 to 5 minutes.  
   
   
       14 . The method of manufacturing a metal gasket, according to  claim 10 , wherein, as conditions of aging treatment for the metal plate having said low-temperature age-hardening characteristics, the temperature is set to not less than 200° C. and less than 250° C., and the length of time is set to 1 to 5 minutes.  
   
   
       15 . The method of manufacturing a metal gasket, according to  claim 7 , wherein the metal plate having said low-temperature age-hardening characteristics is a metastable austenitic stainless steel plate which induces a great deal of martensitic transformation by temper rolling at the final stage of manufacturing of the metal plate.  
   
   
       16 . The method of manufacturing a metal gasket, according to  claim 8 , wherein the metal plate having said low-temperature age-hardening characteristics is a metastable austenitic stainless steel plate which induces a great deal of martensitic transformation by temper rolling at the final stage of manufacturing of the metal plate.  
   
   
       17 . The method of manufacturing a metal gasket, according to  claim 9 , wherein the metal plate having said low-temperature age-hardening characteristics is a metastable austenitic stainless steel plate which induces a great deal of martensitic transformation by temper rolling at the final stage of manufacturing of the metal plate.  
   
   
       18 . The method of manufacturing a metal gasket, according to  claim 10 , wherein the metal plate having said low-temperature age-hardening characteristics is a metastable austenitic stainless steel plate which induces a great deal of martensitic transformation by temper rolling at the final stage of manufacturing of the metal plate.  
   
   
       19 . The method of manufacturing a metal gasket, according to  claim 11 , wherein the metal plate having said low-temperature age-hardening characteristics is a metastable austenitic stainless steel plate which induces a great deal of martensitic transformation by temper rolling at the final stage of manufacturing of the metal plate.  
   
   
       20 . The method of manufacturing a metal gasket, according to  claim 12 , wherein the metal plate having said low-temperature age-hardening characteristics is a metastable austenitic stainless steel plate which induces a great deal of martensitic transformation by temper rolling at the final stage of manufacturing of the metal plate.  
   
   
       21 . The method of manufacturing a metal gasket, according to  claim 13 , wherein the metal plate having said low-temperature age-hardening characteristics is a metastable austenitic stainless steel plate which induces a great deal of martensitic transformation by temper rolling at the final stage of manufacturing of the metal plate.  
   
   
       22 . The method of manufacturing a metal gasket, according to  claim 14 , wherein the metal plate having said low-temperature age-hardening characteristics is a metastable austenitic stainless steel plate which induces a great deal of martensitic transformation by temper rolling at the final stage of manufacturing of the metal plate.  
   
   
       23 . The method of manufacturing a metal gasket, according to  claim 7 , wherein said metal gasket is a metal gasket for a cylinder head of an internal combustion engine.