扩音器前的锥形壳体铝件(L1)原来是由两个零件加工螺孔后用螺钉联结起来的(图1)。现改用冷挤压直接成形的方法制造,不仅节约原材料,而且生产率也大大提高。锥形壳体的冷挤压工序见图2。试验时采用的模具结构见图3。试验是在液压机上用控压法进行,用猪油作润滑剂。当总压力达 The conical housing aluminum part (L1) in front of the loudspeaker was originally screw-fastened by two parts after machining the screw holes (Figure 1). Instead of using direct extrusion cold extrusion manufacturing methods, not only save raw materials, but also greatly enhance productivity. Conical shell cold extrusion process shown in Figure 2. Test the mold structure shown in Figure 3. The test is carried out by hydraulic pressure control method, with lard for lubricants. When the total pressure reaches