1. Bending dies are generally composed of four parts: upper die, lower die, guide rail, and die holder. There are three standard angles: 88°, 90°, and 30° (excluding special dies).
Upper die part: straight blade, straight blade (large, small) bending blade, goose neck (large, medium, small) bending blade, 30-degree pointed blade, flattening blade, simple die, special die, arc cutting tools, etc.
Lower die part: double V-groove V4-V7, V5-V9, V6-V10, V7-V11, V8-V12, V15-V18, etc.
Single V-groove V4, V5, V6, V7, V8, V10, V12, etc.
Die holder part: single groove die holder and double groove die holder. The double groove is divided into low position (55cm), middle position (75cm), and high position (135cm).
2. Different materials require different tools due to their unique structures, resulting in varying acid and alkali resistance, tensile strength, material hardness, elongation coefficient, plasticity, etc. When selecting dies, factors such as machine tool pressure, structure, material, workpiece unfolding size, process requirements, surface treatment, etc., should be considered for a reasonable choice. In general, for iron plates, the slot width of the lower die should be 5-6 times the material thickness, not less than 4 times, and not more than 8 times. For stainless steel, the slot width of the lower die should be 6-8 times the material thickness, not less than 5 times. For aluminum and copper, the slot width of the lower die should be 8-10 times the material thickness (to avoid surface cracks during bending).
3. The selection of the upper die is based on the structure of the workpiece such as avoidance position, avoidance pins, avoidance nuts, etc. When the workpiece needs to avoid left and right positions, bending blades or left and right ear blades can be selected, or special dies can be used.
The lower die is selected based on the shape of the workpiece, whether in the normal or reverse position, mainly used for avoidance positions, avoidance pins, etc. When the size of the workpiece is smaller than the standard size and the unfolding size is small, the off-center method of the lower die can be used under the premise of safety production, with a reasonable offset amount of 1/4 of the V-groove width.
When the ratio of the V-groove to the material thickness is 6 times, for each increase or decrease of one unit (1mm), the workpiece unfolding size should increase or decrease by 0.10mm. When it reaches the limit, there is no significant change.
The selection of special dies should be based on the shape, performance, size, appearance of the structure itself, and the safe height and pressure of the machine. The adjustment of segmented dies is based on the size requirements of the workpiece segments to control the size of the workpiece by adjusting the amount of filler in the die.
