Aluminum based collared header plate for a heat exchanger, especially for a motor vehicle

摘要

An aluminum based header plate, for a tubular heat exchanger for a motor vehicle, has an external coating on its outer face. An end portion of each heat exchanger tube is received in a corresponding through hole in the header plate. The tube end portions have a predetermined cross section and an external coating, and secured to the header plate by brazing. Each through hole is made by a slitting operation followed by configuration of the through hole within a selected zone of the header plate, this zone being press-formed so as to form in the outer face of the header plate a collar portion in that zone. The internal transverse cross section of each collar portion is substantially identical to the predetermined cross section of the corresponding tube end portion. After the tube has been introduced into the through hole, which extends through the collar portion, there is surface contact between the respective external coatings of the collar portion and of the tube end portion.