| 摘要 |
PURPOSE:To manufacture a front grill in the necessary network shape and to improve the productivity by executing stretching after forming a slit on an Al extrusion preform. CONSTITUTION:Numerous cuts or slits 8 are provided in a zigzag arrangement on a web part 6 at the forming position of the front grill of the middle part of the length of an extrusion preform 3. On the other hand, the web 6 is cut off over the necessary length range at the forming position of the opening part for lifting a frame 2 and the cut-off part leaving only upper and lower skeletal cleat parts 4, 5 is formed. At the part where the slit 8 is formed the stretching expanding both skeletal cleat parts 4, 5 is executed in the direction enlarging it and the grill part 1 having numerous vent holes 9 of hexagonal wire mesh is formed. The front grill abundant in variation can thus be obtd. |
