초록 ▼

A heat exchanger has plural flat tubes through which refrigerant flows, and a pair of header tanks disposed on each longitudinal ends of the flat tubes. Each of the flat tubes has a flow passage portion having plural flow passages through which refrigerant flows, and a non-flow passage portion dispo

A heat exchanger has plural flat tubes through which refrigerant flows, and a pair of header tanks disposed on each longitudinal ends of the flat tubes. Each of the flat tubes has a flow passage portion having plural flow passages through which refrigerant flows, and a non-flow passage portion disposed on both sides of the flow passage portion, having at least one non-flow passage through which no refrigerant flows. The flow passage portion is inserted into the header tank so that the flow passages communicate with the header tank, and the non-flow passage portion is exposed outside the header tank. Each of the flow passages has a circular-shaped cross-section while the non-flow passage has a polygonal-shaped cross-section, so that a wall thickness of the non-flow passage is made thinner than that of the flow passages. Therefore, weight of the flat tube is decreased, while sufficient strength thereof is maintained. On the other hand, the header tank has an inner partition wall for partitioning the header tank into first and second tank passages having an oval-shaped cross-section, so that the header tank has high pressure resistance.

대표청구항 ▼

[ What is claimed is:] [1.]1. A heat exchanger comprising:a plurality of tubes, each of said tubes includinga first portion having a first wall portion for forming a plurality of first passages through which a fluid flows in a longitudinal direction of said first portion, anda second portion dispose

[ What is claimed is:] [1.]1. A heat exchanger comprising:a plurality of tubes, each of said tubes includinga first portion having a first wall portion for forming a plurality of first passages through which a fluid flows in a longitudinal direction of said first portion, anda second portion disposed on both sides of said first portion, said second portion having a second wall portion for forming a second passage in which no fluid flows; anda header tank connected to longitudinal ends of said tubes to communicate with said first passages, said header tank extending in a direction perpendicular to a longitudinal direction of said tubes, wherein:each of longitudinal ends of said second portion is recessed from each of the longitudinal ends of said first portion; andsaid second wall portion has a wall thickness thinner than that of said first wall portion.