Reasons and treatment methods for wrinkling of tensile parts
There are many reasons for the wrinkling of the pulling piece, mainly in the following aspects: the stretched blank is not thick enough, the pressure it can bear is naturally small, and it is easy to wrinkle during the stretching process; each blank is not pressed Select the corresponding elongation coefficient for the texture of the material, and the degree of deformation is difficult to control. If the control is not good, deformation will occur; the blank holder is seriously damaged, and the same pressure cannot be applied to the blank, resulting in uneven pressure capacity and wrinkling. .
The thickness of the drawn blank should be relatively thick, so that it can withstand relative pressure during stretching, and it is not easy to deform and wrinkle; choose an appropriate stretching coefficient corresponding to the texture of the blank, and the degree of deformation is easy to control; The rings need to be replaced or repaired frequently, so that the blanks are under equal pressure and are not prone to wrinkling.
1. How to remove wrinkles when stretched parts appear?
1. It has been proved by a large amount of practical experience in production that the main reason for the wrinkling of the stretched parts is the accumulation of materials during the stretching process and the excessive speed of local material movement. When designing the actual solution, the corresponding mechanism of the mold should be adjusted from the above aspects, and good results can be obtained.
2. The way to prevent wrinkling is to determine whether the die head can press the material during stretching, so as to determine the correct flow rate of the sheet. During the drawing process, the flow rate of the sheet material is too fast during the stamping process, which will cause wrinkles; on the other hand, the flow rate of the sheet material is too slow, which may cause the stamping part to crack.
3. When the wrinkles appear evenly around the stretched piece, it should be judged that the pressing force is not enough.
4. When extruding conical and hemispherical parts, most of the material is suspended when the extrusion begins. Since it is easy to cause wrinkling of the side walls, in addition to increasing the blank holder force, the shrinkage ribs should be enlarged to increase the tensile stress in the plate.
5. If the fillet radius of the die is too large, the bending resistance of the blank will be smaller after the blank flows into the die through the fillet of the die. The better the bending resistance, the easier it is to wrinkle. The smaller the diameter of the die, the greater the bending resistance caused by the bending deformation, and the less likely it is to wrinkle, but it is easy to cause cracking and hair pulling of the workpiece.
2. Precautions for the use, maintenance and repair of tensile parts
1. Before using the stretched parts, a strict inspection should be carried out, and the dirt should be cleaned up, and the guide sleeve and the mold of the stretched parts should be carefully checked whether the lubrication is good.
2. According to the installation procedure of the die, install the convex and concave die on the turntable to ensure that the direction of the convex and concave drawing stamping parts is consistent, especially the drawing and pressing parts with direction requirements (non-circular and square) should be careful to prevent wrong installation. opposite.
3. Regularly check the turntable of the bed and the mold mounting seat to ensure the coaxial accuracy of the upper and lower turntables.
4. When installing the mold, the puncher should use softer metal (such as copper, aluminum, etc.) to make the operating tool to prevent the drawing punch from being broken during the installation process.
5. After the cutting edge of the punch and the concave die of the drawn part is worn, stop using it immediately and sharpen it in time, otherwise it will rapidly expand the wear of the cutting edge of the die, accelerate the wear of the die, and reduce the quality of the punching part and the life of the die.
6. In order to ensure the service life of the stretched parts, the die spring should be replaced regularly to prevent the spring fatigue damage and affect the service life of the stretched parts.
The above are the reasons and treatment methods for the wrinkling of the stretched parts. Attention should be paid to the processing and production of the stretched parts. When using mold equipment such as a press or a die, care should be taken to ensure that the strips are carried out under normal working conditions to prevent transportation. The material is fed along the correct position or not according to the corresponding gap. I hope the above can be helpful to readers.