| 摘要 |
PROBLEM TO BE SOLVED: To prevent an erosion at the site of a core (the site at which a molten brazing material is easily stored) which becomes a lower side during a brazing operation. SOLUTION: First recesses 131 in which their recess sizes are increased toward a end side in a widthwise direction, are provided at both end sides of an insert 130 in a widthwise direction. Thus, since the recesses 131 are disposed on a lower side of the core 110 at during brazing operation (in a furnace), the brazing material melted, flows into the recess 131, and is stored and held in the recesses 131 by the surface tension of the brazing material in a brazing process. Accordingly, since the diffusion of the much brazing material to outer fins 112 of the lower side during the brazing operation can be prevented, the occurrence of the erosion due to the diffusion of the material at the fins 112 can be prevented.
|
