The development of numerical control technology ensures the quality and performance of numerical control machine tools in China. Due to the strong adaptability of CNC machine tool to workpiece modification, high machining accuracy of sheet metal cabinet and chassis, high productivity and other characteristics, CNC technology has been widely used in sheet metal machine tool, which solves the problems of high precision and complex shape in sheet metal processing. The application in production greatly improves the sheet metal processing capacity, ensures the sheet metal parts in quality and output, and greatly reduces the labor intensity of workers.
Today we are going to explain how to master the bending accuracy of the sheet metal parts of the chassis cabinet, which plays an important role in the accuracy of the parts.
Gap bending method is a common method of workpiece bending, which is to place the workpiece to be processed between the upper die and the lower die of the bending machine, and complete the processing with the help of the joint action of the upper and lower templates. In the process of processing, the upper and lower templates are not in direct contact with each other, and the mechanical force is applied on both sides of the workpiece to complete the bending process.
The following is the implementation plan:
1. Select the plate with uniform material
Uneven material is an important factor affecting the bending accuracy of workpiece, which leads to the uncertainty of springback in bending. In view of this problem, we should start from the selection of plate, try to choose high-quality plate with uniform material as the material of workpiece bending. At the same time, we should start from the plate manufacturing, with the help of advanced metallurgy, forging process to improve the quality of the plate, improve the overall homogeneity of the plate.
2. Reasonably design the angle and width of the lower die opening
In the actual bending process, because the processing shapes of different workpieces are different, different bending degrees are needed. When selecting the opening angle of the lower die, it is necessary to select a width of the lower die that can meet the processing requirements of the bending parts. If the opening of the lower die is too wide, the inner bending fillet of the workpiece will be too large, the pressure will be reduced, the springback will increase, and the speed of bending will be affected. When the opening width is too small, the pressure will be too large and the load will be too large, resulting in the actual size of the workpiece "over bending". To solve this problem, the delivery width of the lower die opening should be designed reasonably. Specifically, we should choose the material with the same fillet radius and material thickness as the raw material of the bending workpiece, so as to control the opening width of the lower die, and reasonably design the starting angle of the lower die, so as to ensure the accuracy of the workpiece bending.
3. Reduce the bending deformation of the machine tool itself
The main problem of bending deformation of machine tool itself is that the deformation of upper and lower sliders is inconsistent, and with the increase of workpiece size, the influence of bending deformation on machining accuracy is more prominent. Therefore, the structure of the bending machine should be optimized to minimize the bending deformation of the machine itself. Specifically, a wedge structure should be set up above the upper die to compensate the accuracy loss caused by the bending deformation. In the actual processing process, considering the differences of materials and properties of the workpiece, the degree of deformation is different. In order to achieve higher accuracy of deformation compensation, it is necessary to carry out multiple tests, obtain the compensation form, and then carry out mass production to ensure the machining accuracy of the workpiece.
4. Improve the dimensional accuracy of workpiece unfolding
In the process of cabinet processing, the improvement of the dimensional accuracy of workpiece unfolding should be carried out in the following two aspects: one is precision
In order to calculate the cutting length, the deviation of workpiece size should be taken into account, and the intermediate value should be selected as the calculation value. At the same time, the tolerance value should be reasonably allocated. The second is to improve the processing accuracy of the workpiece unfolding and reduce the cutting error.
For each customer and company, perfect product design process is very important, it is an effective guarantee for good product design. Therefore, most industrial design companies will establish a complete and reasonable product design process according to their own services and characteristics to ensure the efficiency and quality of product design.