| 摘要 |
PURPOSE:To form projecting strips at extremely narrow intervals, and to set the fitting intervals (pitches) of fins to small value, also by using an extrusion die material of a sectional shape, in which a large number of the projecting strips are protruded and formed to one surface or both surfaces, as a substrate. CONSTITUTION:A large number of the projecting strips 2, 2' are each protruded and formed to both surfaces of the substrate 1 consisting of the extrusion die material in parallel and at close intervals. These projecting strips 2, 2' are grooved by a metal saw in the direction of the thickness of the substrate from their top surfaces to work grooves 3, but the depth of the grooves 3 can be formed in size, which is larger than the height of the projecting strips 2, 2' and intrudes partially to the thickness of the substrate as shown in the figure. The width of the grooves 3 may be equal to the thickness of the fins to be fitted or be made slightly larger than that. One ends of the plate-shaped fins 4 are fitted into said grooves 3, and the pawl-shaped projecting strips 2 or 2' are crushed so as to hold the fins 4 from the left and the right, thus staking and combining the fins 4 to the substrate 1. |
