An evaporator 1 includes a refrigerant inlet header section 5 and a refrigerant outlet header section 6 which are arranged in the front-rear direction, a refrigerant circulation passage for establishing fluid communication between the header sections 5 and 6 . First ends of the header sections 5 and 6 are closed with a first cap 19 and the second ends thereof are closed with a second cap 18 . A refrigerant inlet 37 and a refrigerant outlet are formed in the first cap 19 . A pipe joint member 21 , having a refrigerant inflow port 45 communicating with the refrigerant inlet 37 and a refrigerant outflow port 46 communicating with the refrigerant outlet 38 , is joined to the first cap 19 . Mating concave portions 19 a and 19 b are formed on the first cap 19 . Mating convex portions 21 a and 21 b which project toward the first cap 19 and which are to be fitted into the mating concave portions 19 a and 19 b , respectively, are formed on the pipe joint member 21 . The second cap 18 has no mating concave portions into which the mating convex portions 21 a, 21 b are fitted. The evaporator ( 1 ) to which the heat exchanger of the present invention is applied can prevent erroneous attachment of the pipe joint member during manufacture thereof.
1. A heat exchanger comprising a refrigerant inlet header section and a refrigerant outlet header section which are arranged in parallel in a front-rear direction, and a refrigerant circulation passage for establishing communication between the header sections, wherein a refrigerant inlet is formed in the refrigerant inlet header section at a first end, and a refrigerant outlet is formed in the refrigerant outlet header section at the same end; and refrigerant having flowed from the refrigerant inlet into the refrigerant inlet header section returns to the refrigerant outlet header section after passing through the refrigerant circulation passage, and flows out of the refrigerant outlet, wherein
the first ends of the refrigerant inlet header section and the refrigerant outlet header section are closed by a first cap joined to the two header sections while bridging them, and second ends of the refrigerant inlet header section and the refrigerant outlet header section are closed by a second cap joined to the two header sections while bridging them; the refrigerant inlet is formed in a portion of the first cap which closes the refrigerant inlet header section, and the refrigerant outlet is formed in a portion of the first cap which closes the refrigerant outlet header section; a pipe joint member having a refrigerant inflow portion communicating with the refrigerant inlet and a refrigerant outflow portion communicating with the refrigerant outlet is joined to the first cap; a mating concave portion is formed on the first cap, and a mating convex portion is formed on the pipe joint member such that the mating convex portion projects toward the first cap and is fitted into the mating concave portion; and the mating concave portion, into which the mating convex portion is fitted, is not formed on the second cap.
2. A heat exchanger according to claim 1 , wherein the pipe joint member assumes a plate-like shape; and the first and second caps have the same outer shape, except for the mating concave portion.
3. A heat exchanger according to claim 1 , wherein the mating concave portion is formed on the first cap at a position offset from the center thereof with respect to the front-rear direction.
4. A heat exchanger according to claim 1 , wherein the mating concave portion comprises a cutout formed in a peripheral edge portion of the first cap.
5. A heat exchanger according to claim 1 , wherein the refrigerant outlet header section is disposed on the rear side of the refrigerant inlet header section; the refrigerant circulation passage is formed by a refrigerant inflow intermediate header section disposed below the refrigerant inlet header section in opposition thereto, a refrigerant outflow intermediate header section disposed below the refrigerant outlet header section in opposition thereto, and a plurality of heat exchange tubes; the refrigerant inflow intermediate header section and the refrigerant outflow intermediate header section communicate with each other; at least one heat exchange tube group including a plurality of heat exchange tubes arranged at intervals along the longitudinal direction of the header sections is disposed between the refrigerant inlet header section and the refrigerant inflow intermediate header section and between the refrigerant outlet header section and the refrigerant outflow intermediate header section, whereby a heat exchanger core section is formed; and opposite end portions of the heat exchange tubes of the heat exchange tube group are connected to the opposed header sections.