Multi-layer type heat exchanger

A multi-layer type heat exchanger including:

• a row of a plurality of substantially parallel flat tubes each formed by two core plates prepared by press work and sealingly jointed together;
• each flat tube including a pair of tank portions spaced widthwise of the flat tube and formed by protrusions formed in one end of each of the two core plates of the flat tube and protruding laterally outwardly of the flat tube;
• the protrusions on each core plate defining therein holes providing inlet and outlet for a first heat transfer fluid;
• each flat tube defining therein a first passage for said first heat transfer fluid, said passage being communicated at its opposite ends with said tank portions and arranged such that said heat transfer fluid flows from one of the two tank portions into said first passage towards the other end of said flat tube and is turned and flows to the other tank portion;
• the flat tubes being successively stacked in the direction of the thickness of each flat tube so that the protrusions on each core plate of each flat tube, excepting the outermost core plates, abuts against the protrusions of an adjacent core plate of an adjacent flat tube and the holes in the abutting protrusions are sealingly connected with each other;
• a corrugated fin disposed between and secured to adjacent core plates of each adjacent pair of flat tubes;
• and
• adjacent core plates of each adjacent pair of flat tubes having bent end portions extending to and integrally connected with each other to support, in spaced relationship, the other ends of the adjacent flat tubes in the direction of the thicknesses thereof
• and prevent the corrugated fin therebetween from being collapsed.