Resin heat exchanger unit, method for manufacturing the resin heat exchanger unit, and heat exchanger
In a resin heat exchanger unit, a resin pipe having straight portions and curved portions and a plurality of resin fins are integrally molded and there can be realized high reliability, high heat exchange efficiency, and a simple manufacturing process. The resin heat exchanger unit includes a resin pipe ( 1 ), which has straight portions ( 2 ) and curved portions ( 3 ) provided alternatively and continuously, and a plurality of resin fins ( 4 ) connected to the pipe ( 1 ), the pipe ( 1 ) and the fins ( 4 ) being integrally injection-molded.
1. A method for manufacturing a resin heat exchanger unit, comprising:
injecting a molten resin into a pipe cavity of a mold, the pipe cavity having on its one end a pressure port provided with a floating core and on its other end and outlet;
pressure-injecting a pressurized fluid through the pressure port after the injection of the molten resin; and
moving the floating core to the outlet side, and, at the same time, extruding the molten resin from the outlet, so as to obtain the resin heat exchanger unit, wherein
the resin heat exchanger unit comprises:
a pipe formed of the resin and having straight portions and curved portions provided alternatively and continuously; and
a plurality of fins formed of the resin and connected to the pipe, the pipe and the plurality of fins being integrally injection-molded.
2. The method for manufacturing a resin heat exchanger unit according to claim 1 , wherein an average thickness of the fin is not less than Tp/20 and not more than Tp, wherein Tp is an average thickness of the pipe.
3. The method for manufacturing a resin heat exchanger unit according to claim 2 , wherein the thickness of the front end of the fin is not less than Tr/10 and more than Tr, wherein Tr is the thickness of the portion of the fin in contact with the pipe).
4. The method for manufacturing a resin heat exchanger unit according to any one of claims 1 to 3 , wherein the resin is a thermoplastic resin.
5. The method for manufacturing a resin heat exchanger unit according to claim 1 , wherein the fin is perpendicular to the axial direction of the straight portion of the pipe.
6. The method for manufacturing a resin heat exchanger unit according to claim 1 , wherein the resin heat exchanger unit further comprises an outer frame formed of a resin and integrally injection-molded with the pipe.
7. A method for manufacturing a resin heat exchanger comprising the step of joining a plurality of the resin heat exchanger units manufactured by the method of claim 1 through a header tank.