Housing for turbocharger and method for manufacturing the same

Abstract

A housing for a turbocharger is dividedly formed of at least a scroll piece and a shroud piece, including a refrigerant flow path for cooling a diffuser surface. The refrigerant flow path is composed of an annular space defined by a first flow-path formation part of the scroll piece and a second flow-path formation part of the shroud piece, which are formed respectively in each opposing part of the scroll piece and the shroud piece facing each other. The first and second flow path formation parts are in contact with each other to form a contact portion at the outermost periphery of an inside surface of the refrigerant flow path. The contact portion has a groove formed by recessing the inside surface of the refrigerant flow path outwardly in the radial direction continuously in the circumferential direction. The groove is filled with a sealing material for sealing the contact portion.

1 . A housing for a turbocharger in which a compressor impeller is housed, the housing comprising:
 a shroud part that surrounds the compressor impeller in a circumferential direction and has a shroud surface facing the compressor impeller;   a diffuser part that is formed on an outer peripheral side of the compressor impeller in the circumferential direction and forms a diffuser passage, the diffuser passage allowing compressed air discharged from the compressor impeller to pass therethrough;   a scroll chamber formation part that forms a scroll chamber for guiding the compressed air passing through the diffuser passage to an outside; and   a refrigerant flow path that is formed along the diffuser part in the circumferential direction, and allows a refrigerant for cooling the diffuser part to pass therethrough, wherein   the housing is composed of a scroll piece including at least part of the scroll chamber formation part, and a shroud piece including at least part of the scroll chamber formation part, the diffuser part, and the shroud part and being inserted in an inner side of the scroll piece,   the refrigerant flow path is composed of an annular space that is defined by a first flow-path formation part of the scroll piece and a second flow-path formation part of the shroud piece, the first flow-path formation part and the second flow-path formation part being formed respectively in each opposing part of the scroll piece and the shroud piece which face each other,   the first flow path formation part and the second flow path formation part are brought into contact with each other to form a contact portion at a position corresponding to an outermost periphery of an inside surface of the refrigerant flow path,   the contact portion has a groove that is formed by recessing the inside surface of the refrigerant flow path outwardly in a radial direction and is continuous in a circumferential direction, and   the groove is filled with a sealing material for sealing the contact portion.   
     
     
         2 . The housing for a turbocharger according to  claim 1 , wherein the groove is formed such that an imaginary circle centered on a shaft center of the compressor impeller is positioned inside of the groove. 
     
     
         3 . The housing for a turbocharger according to  claim 1 , wherein the groove has a shape notched into a V shape outwardly in the radial direction such that a deepest position of the groove in a cross section including the shaft center of the compressor impeller is positioned on a boundary between the first flow path formation part and the second flow path formation part. 
     
     
         4 . The housing for a turbocharger according to  claim 2 , wherein the groove has a shape notched into a V shape outwardly in the radial direction such that a deepest position of the groove in a cross section including the shaft center of the compressor impeller is positioned on a boundary between the first flow path formation part and the second flow path formation part. 
     
     
         5 . The housing for a turbocharger according to  claim 1 , wherein the sealing material is provided between the scroll piece and the shroud piece at the contact portion, and seals a space between the scroll piece and the shroud piece. 
     
     
         6 . The housing for a turbocharger according to  claim 2 , wherein the sealing material is provided between the scroll piece and the shroud piece at the contact portion, and seals a space between the scroll piece and the shroud piece. 
     
     
         7 . The housing for a turbocharger according to  claim 3 , wherein the sealing material is provided between the scroll piece and the shroud piece at the contact portion, and seals a space between the scroll piece and the shroud piece. 
     
     
         8 . The housing for a turbocharger according to  claim 4 , wherein the sealing material is provided between the scroll piece and the shroud piece at the contact portion, and seals a space between the scroll piece and the shroud piece. 
     
     
         9 . The housing for a turbocharger according to  claim 1 , wherein a contact surface of the scroll piece and a contact surface of the shroud piece at the contact portion are parallel to a surface perpendicular to a shaft direction. 
     
     
         10 . The housing for a turbocharger according to  claim 2 , wherein a contact surface of the scroll piece and a contact surface of the shroud piece at the contact portion are parallel to a surface perpendicular to a shaft direction. 
     
     
         11 . The housing for a turbocharger according to  claim 3 , wherein a contact surface of the scroll piece and a contact surface of the shroud piece at the contact portion are parallel to a surface perpendicular to a shaft direction. 
     
     
         12 . The housing for a turbocharger according to  claim 4 , wherein a contact surface of the scroll piece and a contact surface of the shroud piece at the contact portion are parallel to a surface perpendicular to a shaft direction. 
     
     
         13 . The housing for a turbocharger according to  claim 5 , wherein a contact surface of the scroll piece and a contact surface of the shroud piece at the contact portion are parallel to a surface perpendicular to a shaft direction. 
     
     
         14 . The housing for a turbocharger according to  claim 6 , wherein a contact surface of the scroll piece and a contact surface of the shroud piece at the contact portion are parallel to a surface perpendicular to a shaft direction. 
     
     
         15 . The housing for a turbocharger according to  claim 7 , wherein a contact surface of the scroll piece and a contact surface of the shroud piece at the contact portion are parallel to a surface perpendicular to a shaft direction. 
     
     
         16 . The housing for a turbocharger according to  claim 8 , wherein a contact surface of the scroll piece and a contact surface of the shroud piece at the contact portion are parallel to a surface perpendicular to a shaft direction. 
     
     
         17 . A method for manufacturing the housing for a turbocharger according to  claim 1 , the method comprising:
 a preparation step of preparing the scroll piece and the shroud piece;   an assembling step of assembling the shroud piece to the scroll piece by press-fitting, and bringing the first flow-path formation part into contact with the second flow-path formation part, thereby forming the refrigerant flow path composed of the annular space;   a providing step of providing a sealing material having a fluidity by feeding the sealing material to the refrigerant flow path after the assembling step, or by applying the sealing material to at least one of the first flow-path formation part and the second flow-path formation part prior to the assembling step;   a filling step of filling the groove with the sealing material by rotating the scroll piece and the shroud piece around the shaft center of the compressor impeller; and   a curing step of curing the sealing material filling the groove.   
     
     
         18 . A method for manufacturing the housing for a turbocharger according to  claim 16 , the method comprising:
 a preparation step of preparing the scroll piece and the shroud piece;   an assembling step of assembling the shroud piece to the scroll piece by press-fitting, and bringing the first flow-path formation part into contact with the second flow-path formation part, thereby forming the refrigerant flow path composed of the annular space;   a providing step of providing a sealing material having a fluidity by feeding the sealing material to the refrigerant flow path after the assembling step, or by applying the sealing material to at least one of the first flow-path formation part and the second flow-path formation part prior to the assembling step;   a filling step of filling the groove with the sealing material by rotating the scroll piece and the shroud piece around the shaft center of the compressor impeller; and   a curing step of curing the sealing material filling the groove.   
     
     
         19 . The method for manufacturing the housing for a turbocharger according to  claim 17 , wherein lathe machining for forming the shroud surface is performed in the filling step simultaneously with filling the groove with the sealing material. 
     
     
         20 . The method for manufacturing the housing for a turbocharger according to  claim 18 , wherein lathe machining for forming the shroud surface is performed in the filling step simultaneously with filling the groove with the sealing material.