What problems should be paid attention to in the stamping and rolling of steel plate

Hinges and hinges are the more common products of steel stamping and rolling. The processing technology of these two products has been very mature, but when it comes to the rolling and hemming of other products, many people are not familiar with them. In fact, the main points of the processing of steel plate coiling are as follows: (1) The diameter of the cylindrical coil should not be too small or too large. The cylindrical coil should be rounded with an axial die. The diameter of the coil should not be too small or too large. , Too small coil diameter is prone to instability in the force transmission zone, on the contrary, too large coil diameter is prone to cracking in the deformation zone. (2) The relative diameter of the cylindrical coil should not be too small. The relative diameter of the cylindrical coil has a great influence on the shape of the coil. When the relative diameter is large (such as greater than 50), the axially compressed cylinder is prone to diamond instability. When the relative diameter is small (such as less than 20), the axially compressed cylinder is prone to axisymmetric instability. Generally, When the relative diameter is between 2050, the curling shape is stable and the curling quality is better. (3) Tube coiling should not be made of materials with poor plasticity. When the tube is coiled, the tube end bears greater plastic elongation. When the plastic elongation exceeds the material's ultimate elongation, the tube end will crack. The larger the radius of the coil, the greater the degree of deformation, and the easier the pipe end to crack. Therefore, pipe coils should use materials with better plasticity, such as pure aluminum and deformed aluminum alloy pipes, brass pipes, low-carbon steel pipes, and austenitic stainless steel pipes. (4) When the rolling quality requirements are high, the guide tube at the end of the tube cannot be ignored. Generally, the rolling can be achieved by axially pressing the tube on the tapered die, fillet die or trough die. However, the quality of the rounding obtained by them is different. When the tapered mold is rounded, the pipe end is easy to slide and freely deform, and the pipe end is not easy to round. However, the shape of the mold used is simple, which is convenient for processing and manufacturing. The most important process parameter for rounding is the half-cone angle of the mold. Only when the half-cone angle satisfies the following relationship, the rounding can be realized. The half-cone angle of the conical die should be greater than 60 degrees, otherwise it can achieve rounding. When the round corner mold is used for rounding, the tube blank has a good centering of the mold. When the tube end is curled, it is restricted and guided by the rounded part of the mold. The rounding quality is better than that of the tapered mold, but the tube end is out of the mold circle. The corners are free to deform, so the defect of out of roundness still exists. When the rolling quality requirements are high, slot molds should be used. The characteristic of the trough mold is that the tube blank can be easily positioned, centered and forced to deform the tube, so that the rounding can be carried out completely according to the shape of the mold, so the rounding quality is better, but the trough mold is difficult to process, and the friction resistance is large when the tube is rolled. It is easy to cause instability, therefore, the surface roughness value of the arc surface of the mold should be high, and it should usually be polished. (5) Hinge rolling should not ignore the design of the shape. Hinge parts are common hardware products, and the rolling process is the key to forming. Generally, the rounding of hinge parts is to pre-bend the blank head and then round. In the pre-bending process, the 75-80 degree arc segment of the bent end is generally not easy to form, so the arc center of the cavity is offset inward to make the local material extruded to facilitate the rounding. Previous post: Punching and flanging is very simple, pay attention to these points to turn out beautiful edges