中、小型电机风罩（图1）形状复杂，口部的转角半径，壁部和轴向均是圆弧形，底部为环形圆角。整个零件要求轮廓清晰。其成形一般是先用拉深模制作毛胚．然后用全整形模达到要求。而所用全整形模具是要求精确的凸凹钢模，这样复杂的钢模要用机械加工的方法来制造，技术难度大， Medium and small motor hood (Figure 1) complex shape, corner of the mouth radius, the wall and the axial are arc-shaped, the bottom of the circular fillet. The entire part requires a clear outline. Its formation is generally the first use of drawing die made of embryos. Then use the full plastic mold to meet the requirements. The use of full plastic mold is required precision punch and die, so complex steel mold to use machining methods to create, technical difficulty,