摘要 |
The radiator contains a large number of transverse through holes (15). Two or more sidewalls (22,24) spaced apart and preferably parallel are sealed together by a peripheral one (25). The holes are formed by distance-sleeves (20) joining the sidewalls together at the perforations. The peripheral wall can be formed by bending over one of the sidewalls at the periphery. The sleeves can be welded by laser to the sidewall inside surfaces, the weld seam forming a watertight joint. |