Knowledge of structural design of sheet metal parts (IV): Configuration criteria of stretched parts

Configuration criterion of deep drawing parts

a. The shape of drawing parts shall be as simple and symmetrical as possible.

b. The size proportion of each part of the drawing part shall be appropriate, and the drawing parts with wide flange and large depth shall be avoided as far as possible. (d convex > 3D, H ≥ 2D) because such parts need more drawing times.

c. The fillet radius of deep drawing parts shall be appropriate, and the fillet radius shall be larger as far as possible, so as to facilitate forming and reduce the number of deep drawing.

 (1) fillet radius of drawing parts. Quick screening sheet metal sample library.

(2) suitable position for punching of deep drawing parts or bending parts.

(3) prevent distortion and deformation during deep drawing. The width of A and B shall be equal (symmetrical), i.e. A=B.

(4) precautions for dimension marking on drawing of stretched parts

The thickness of the material after stretching is changed because the stress of the stretched part is different. Generally speaking, the center of the bottom maintains the original thickness, the material at the bottom fillet becomes thinner, the material at the top near the flange becomes thicker, and the material at the fillet around the rectangular tensile part becomes thicker.

 (5) standard method for product size of stretched parts

When designing stretched products, the dimensions on the product drawing shall be clearly indicated. The external or internal dimensions must be guaranteed, and the internal and external dimensions cannot be marked at the same time.

 (6) marking method of dimensional tolerance of stretched parts

The inner radius of the concave convex arc of the stretching part and the height dimension tolerance of the once formed cylindrical stretching part are double-sided symmetrical deviation, and the deviation value is half of the absolute value of the accuracy tolerance of grade 16 in the national standard (GB), and is marked with ± sign.