Heat exchanger

摘要

An upper tank of a heat exchanger for an automotive vehicle is divided into an upper room and a lower room by a partition wall, on which a positive pressure valve and a negative pressure valve are provided for respectively forming a passageway from the lower room to the upper room when the pressure in the lower room exceeds a predetermined value and a passageway from the upper room to the lower room when the pressure in the lower room becomes lower than a predetermined value, whereby the upper room serves as a reserve tank.