Press forming, not punch press..punch press may be possible but not cost effecient...a completly NEW DESIGN in this area would be incouraged, that is a total new design radiator from the ground up. maybe even non-metal construction..>>from the internet>>, Manufacturing a core plate used for the heat exchanger, comprising the step of press-forming with a first press-die which is arranged on one end side of a plate-shaped member in the wall thickness direction having protrusions protruding to the other end side in the wall thickness direction, and with a second press-die which is arranged on the other end side of the plate-shaped member in the wall thickness direction having protrusions protruding to the one end side in the wall thickness direction.
Due to the foregoing, the recessed and the protruded portions are formed substantially symmetrically with the plate face (reference face) before the formation. Therefore, a direction of the residual stress generated in the process of press forming becomes substantially symmetrical, and the residual stress can be canceled.
Accordingly, it is possible to prevent the core plate from being deformed when the wave-shaped portion is formed, and deterioration of the manufacturing yield of the core plate can be prevented.<<. INVENT SOMETHING NEW. good luck
