Abstract: The invention relates to a cooling fluid cooler for motor vehicles having a soldered cooling network (1) made of flat tubes (101) and ribs (102), produced from very thin aluminum sheets (a, b, c), and having header or loop-around chambers (3) at the ends of the flat tubes (101) for the cooling fluid flowing in the flat tubes (101), said chambers being cooled by cooling air flowing through the ribs (102). The cooling fluid cooler has exceptional cooling power and a light weight. This is achieved according to the invention in that each flat tube (101) is made of at least two formed sheet metal strips (a, b, c), wherein at least the one sheet metal strip (a, b) forms the wall of the flat tube and the other sheet metal strip forms a wavy internal insert (c) forming channels (10) in the same, and that the ratio of the constriction factor on the cooling fluid side to the constriction factor on the cooling air side is approximately in the range of 0.20 to 0.

Abstract: The invention relates to a cooling fluid cooler for motor vehicles having a soldered cooling network (1) made of flat tubes (101) and ribs (102), produced from very thin aluminum sheets (a, b, c), and having header or loop-around chambers (3) at the ends of the flat tubes (101) for the cooling fluid flowing in the flat tubes (101), said chambers being cooled by cooling air flowing through the ribs (102). The cooling fluid cooler has exceptional cooling power and a light weight. This is achieved according to the invention in that each flat tube (101) is made of at least two formed sheet metal strips (a, b, c), wherein at least the one sheet metal strip (a, b) forms the wall of the flat tube and the other sheet metal strip forms a wavy internal insert (c) forming channels (10) in the same, and that the ratio of the constriction factor on the cooling fluid side to the constriction factor on the cooling air side is approximately in the range of 0.20 to 0.

Abstract: The present invention relates to a heat exchanger, in particular, an oil cooler for motor vehicles, constructed from trough-shaped heat exchanger plates which are stacked into one another and from turbulence inserts, having two openings for one medium and two further openings for another medium in order to form collecting ducts for the supply and discharge of the media, with flow ducts for the media being formed between the heat exchanger plates. The heat exchanger also includes flow ducts connected to the associated collecting ducts, an upper closure plate which has convexities in the region of the collecting tanks, and an intermediate plate which is provided with holes. The intermediate plate is arranged between the closure plate and the uppermost heat exchanger plate, and one of the holes, formed as a pressure equalizing opening, interacts with the upwardly aligned convexity in the closure plate to improve the internal pressure stability.