In modern industrial production, metal forming technology plays a vital role, which involves sheet metal working, metal processing and many other aspects. In particular, metal drawing is highly respected in the manufacturing industry for its efficiency and precision. Metal drawing is the process of forming a product by stretching the sheet through a drawing die to form the desired shape.
(1) Stretching depth affects the distribution of material flow resistance along the concave mold opening, which is directly related to the stretching depth. Concave and convex curve position, stretching depth is too large can cause uneven distribution of deformation resistance, the formation of wrinkles, should be avoided as far as possible.
(2) Adjust the size of the crimping force when the wrinkles in the parts around the uniform production, should be judged as insufficient pressure, and gradually increase the pressure can be eliminated wrinkles. When stretching conical and hemispherical parts, most of the material is in suspension at the beginning of stretching. Easily produce side wall wrinkles, so in addition to increase the pressure edge force, should also be used to increase the pick up stretching rib to increase the radial tensile stress in the plate to eliminate wrinkles.
(3) the radius of the concave mold radius of the concave mold is too large, the blank to the concave mold flow through the concave mold corner is to produce bending deformation of the bending resistance is smaller. The smaller the bending resistance, the more likely to cause the occurrence of wrinkles. Concave mold radius is small bending deformation of the bending resistance is greater, the less prone to wrinkle, but easy to cause cracking and hair pulling phenomenon. Through a large number of production practice experience has proved that the main reason for the wrinkling of stamping parts is the accumulation of material in the stretching process and the local material movement speed is too fast. In the development of practical solutions, should be considered from the above aspects to adjust the corresponding mechanism of the mold, will achieve good results.
Measures and methods to prevent wrinkling of stamped parts
The method of preventing wrinkles is to ensure that the hardware stamping parts in the stretching process mold can press the material to ensure a reasonable speed of plate material flow. Stamping parts in the stretching of sheet material flow too fast, it can cause wrinkles; on the other hand, sheet material flow is too slow, it can cause stamping parts cracking.
(1) The use of reasonable pressure device when the pressure device, the pressure device will be deformed part of the blank tightly pressed in, and its role in the pressure force to prevent the flange part of the arch caused by wrinkles. The size of the pressing force should be appropriate. Pressing device is divided into two categories of elastic pressing and rigid pressing. The elastic device is suitable for shallow drawing, and the rigid device is suitable for deep drawing.
(2) Reasonable use of stretching tendons in the pressing surface to set stretching tendons is to regulate and control the deformation resistance of an effective and use of methods. Stretching tendon can well regulate the flow of material, so that the stretching process in all parts of the material flow resistance is uniform, so that the amount of material flowing into the cavity is suitable for the needs of the parts, to prevent more than wrinkles, less than the phenomenon of cracking. For the complex shape of the curved surface of the tensile parts, especially the flange is small tensile parts, should be set up stretching bar, in order to improve the radial tensile stress to control the wrinkle; stretching bar set up in the radial tensile stress on the part of the smaller, that is, easy to flow parts of the plate material. For parts with small flanges, in order to set up the stretching rib, can be appropriate to add some material (process supplemental material), trimming and then remove this part. For stretching parts with large difference in stretching depth, the stretching rib should be set on the part with less feed, so that the excess material in the part can be organized to pull people into the cavity of the concave die, thus preventing wrinkles.
Stretching parts wrinkled reason analysis stretching parts wrinkled in the stretching process for many reasons, the main reasons are the following aspects:
(1) stamping parts stretching depth is too deep, resulting in parts in the process of material flow too fast, the formation of wrinkles.
(2) Stamping parts in the stretching process of the concave die R angle is too large, resulting in the stretching process of the convex die can not hold down the material, resulting in the formation of wrinkles in the sheet flow too fast.
(3) The press bar of the stamping part is unreasonable, the press bar is too small and the position is incorrect, which can't effectively prevent the sheet from flowing too fast, forming wrinkles.
(4) The pressure of the top bar is too small, so that the molding of stamped parts is not complete, forming wrinkles.
(5) The mold positioning design is unreasonable, resulting in the stamped parts can not be pressed during the stretching process or the edge of the press is too small, resulting in the material can not be pressed during the stretching process, resulting in wrinkles.
(6) Convex-concave mold clearance is too large, resulting in the stretching process can not hold the material, resulting in wrinkles.
The above are common reasons for wrinkles in the stretching process of stamping parts, in the specific problems need to be specifically analyzed. According to the specific circumstances of the stamping parts to find specific reasons.