Heat exchanger

Abstract

A heat exchanger includes a tank, multiple tubes, a tube support member that supports the multiple tubes, and a shell body joined to the tube support member. The tube support member is cylindrical and includes a first-end cylindrical portion, a second-end cylindrical portion, and an intermediate cylindrical portion having a diameter smaller than that of the first-end cylindrical portion and having a predetermined length in an axial direction between the first-end cylindrical portion and the second-end cylindrical portion. The tank and the first-end cylindrical portion are welded to each other. The shell body and the second-end cylindrical portion are brazed to each other. Outer peripheral portions of the tubes are in contact with and brazed to an inner surface of the intermediate cylindrical portion.

What is claimed is: 
     
         1 . A heat exchanger comprising:
 a tank into or from which a first fluid flows;   a plurality of tubes through which the first fluid flows;   a tube support member which is joined to and supports the plurality of tubes, the tube support member being joined to the tank; and   a shell body which accommodates therein the plurality of tubes such that a second fluid flows around the tubes, the shell body being joined to the tube support member, wherein   the tube support member is a cylindrical body extending in an alignment direction along which the tank and the shell body are aligned,   the tube support member includes:
 a first-end cylindrical portion provided on a first end part of the cylindrical body in an axial direction, 
 a second-end cylindrical portion provided on a second end part of the cylindrical body in the axial direction, and 
 an intermediate cylindrical portion which is smaller in diameter than the first-end cylindrical portion and is between the first-end cylindrical portion and the second-end cylindrical portion, the intermediate cylindrical portion having a predetermined length in the axial direction, 
   the tank and the first-end cylindrical portion are welded to each other,   the shell body and the second-end cylindrical portion are brazed to each other,   outer peripheral portions of the plurality of tubes are in contact with and brazed to an inner surface of the intermediate cylindrical portion such that the tube support member supports the outer peripheral portions of the plurality of tubes, and   a brazed joint between the shell body and the second-end cylindrical portion is located inward in the axial direction more than brazed joints between the outer peripheral portions of the plurality of tubes and the intermediate cylindrical portion.   
     
     
         2 . The heat exchanger according to  claim 1 , wherein
 the plurality of tubes form a tube assembly in which the adjacent tubes are in contact with and stacked integrally on each other, and   the outer peripheral portions of the tube assembly are in contact with and brazed to the inner surface of the intermediate cylindrical portion such that the tube support member supports the outer peripheral portions of the tube assembly.   
     
     
         3 . The heat exchanger according to  claim 1 , wherein the intermediate cylindrical portion is smaller in diameter than the second-end cylindrical portion. 
     
     
         4 . The heat exchanger according to  claim 3 , wherein the tube support member includes:
 a first connector which is an annular plate portion extending in a direction intersecting with the axial direction and connects the intermediate cylindrical portion and the first-end cylindrical portion; and   a second connector which is an annular plate portion extending in the direction intersecting with the axial direction and connects the intermediate cylindrical portion and the second-end cylindrical portion.   
     
     
         5 . The heat exchanger according to  claim 1 , wherein the first-end cylindrical portion is an annular plate portion extending in a direction intersecting with the axial direction and being welded to the tank. 
     
     
         6 . The heat exchanger according to  claim 5 , wherein the second-end cylindrical portion is an annular plate portion extending in a direction intersecting with the axial direction and being brazed to the shell body. 
     
     
         7 . The heat exchanger according to  claim 1 , wherein
 the tube support member has a block shape and is larger in thickness in longitudinal cross-section than the plurality of tubes, the tank, and the shell body,   the intermediate cylindrical portion is located radially inward of the first-end cylindrical portion and the second-end cylindrical portion, and   the respective joints in the first-end cylindrical portion, the intermediate cylindrical portion, and the second-end cylindrical portion are spaced apart from each other in the axial direction.   
     
     
         8 . The heat exchanger according to  claim 7 , wherein the intermediate cylindrical portion is an annular projection portion protruding radially inward of the tube support member more than the first-end cylindrical portion and the second-end cylindrical portion. 
     
     
         9 . The heat exchanger according to  claim 7 , wherein
 the intermediate cylindrical portion has an inner peripheral surface of the tube support member which is in contact with and brazed to the outer peripheral portions of the plurality of tubes,   the first-end cylindrical portion has an outer peripheral surface of the tube support member which is in contact with and welded to the tank, and   the second-end cylindrical portion has an outer peripheral surface of the tube support member which is in contact with and brazed to the shell body.   
     
     
         10 . The heat exchanger according to  claim 8 , wherein a thickness of the intermediate cylindrical portion in a radial direction of the tube support member is twice or more of a thickness of the first-end cylindrical portion in the radial direction. 
     
     
         11 . The heat exchanger according to  claim 7 , wherein
 the intermediate cylindrical portion has an inner peripheral surface which is in contact with and brazed to the outer peripheral portions of the plurality of tubes,   the first-end cylindrical portion has a groove recessed from an end face of the first end part of the tube support member toward the second end part such that the tank is fitted to the groove and welded to the first-end cylindrical portion, and   the second-end cylindrical portion has a groove recessed from an end face of the second end part of the tube support member toward the first end part such that the shell body is fitted to the groove and brazed to the second-end cylindrical portion.