Pressure vessel, compressor and process for casting cylinder block

Abstract

A pressure vessel of the present invention is such that at least part thereof comprises a metallic composite material 40 comprising a light metal 41, which is turned into a matrix, and a plate-shaped iron-based member 42, which is buried in the light metal 41, whose major component is iron, and which is provided with a large number of through holes penetrating the front and rear surfaces. By means of this construction, it is possible to provide a pressure vessel having a novel construction whose pressure resistance is enhanced without being accompanied by thickening, and a compressor being provided with a housing comprising the pressure vessel. Moreover, a casting process of the present invention is a casting process, which is suitable for producing cylinder blocks, and is characterized in that, in a casting mold 80 being provided with hollow portions ( 86, 87 ) forming a molding cavity surface 84, and a pouring passage 85 which is communicated with the hollow portions, a substantially cylindrical iron-based member 42 having cut-offs 45 at the opened end portions is allocated so that the opened end portions are brought into contact with the molding cavity surface 84 and spaces 86, 87 are provided on the front- and rear-surface sides of the iron-based member 42, and a light-metal molten metal 41 ′ is filled into the entire hollow portions through the pouring passage 85 via the cut-offs 45, thereby casting the light metal 41 around the iron-based-member 42.

1 . A process for casting a cylinder block, being characterized in that it comprises:
 an iron-based-member allocation step of allocating a substantially cylindrical iron-based member, whose major component is iron, which is provided with a large number of through holes penetrating the front and rear surfaces and whose open area ratio is 13-30%, in a casting mold being provided with a hollow portion forming a molding cavity surface, which corresponds to the shape of a cylinder block, in cooperation with a core for a cylinder bore, and a pouring passage into which a molten metal is poured and which is communicated with the hollow portion, at least, coaxially with the core for a cylinder bore; and   a light-metal filling step of filling said molten metal of a light metal into said hollow portion through said pouring passage;   wherein said light metal is cast around said iron-based member by way of the steps.   
   
   
       2 . The process for casting a cylinder block set forth in  claim 1 , wherein:
 said iron-based member has at least one cut-off at an opened end portion of the iron-based member, the cut-off being larger than the area of one of said through holes, and is allocated so that the opened end portion is brought into contact with said molding cavity surface and spaces are provided on the front- and rear-surface sides of the iron-based member in said iron-based-member allocation step; and   the molten metal is filled into the entire hollow portion via the cut-off in said light-metal filling step.   
   
   
       3 . The process for casting a cylinder block set forth in  claim 1 , wherein said molding cavity surface has a holding portion for holding the opened end portion of said iron-based member.