Bending stamping production, a more widely used process, this process can be used not only for the manufacture of large-scale structural parts such as airplanes, automobiles, but also for the manufacture of electronic instruments, electronic components and other small machine structural parts. Although the use of bent parts is more extensive, but in the production, there are often quality problems, such as: spring back, offset and bending cracks and so on.
In order to avoid the above problems and improve the accuracy of the bent parts, the hook network introduces some specific measures for your reference.
A specific measure to reduce the elastic compound
1, in the design of the workpiece to improve some of the structure to promote the elastic compound smaller
Let the reinforcement in the bending area to be suppressed, so as to improve the stiffness of the workpiece has certain help, but also conducive to let the spring back to be suppressed. In addition, to meet the conditions of use, you can choose materials with a small yield limit, modulus of elasticity, mechanical properties of the characteristics of stability, in order to reduce the bending of the elastic compound.
2, from the mold design to consider reducing the elastic compound
For general materials, can be made in the convex and concave molds equal to the angle of the slant of the spring back, so that the workpiece is exactly equal to the required angle of the spring back. For more than 0.8mm thickness of plastic materials, in the convex mold to make a “protruding” part, bending this part of the workpiece can be corrected at the rounded corners, this method can effectively overcome the elastic compound. For the material with a large elastic compound, the convex die and the top plate can be made into a curved surface, when the bent workpiece is removed from the mold, the curved surface part of the straightening compensation for the elastic compound.
3, the use of bending process
For the bending radius is very large, the elastic compound is not easy to eliminate the bending parts, the use of bending process can make the blank from the inner surface to the outer surface of the tensile stress, unloading their elastic deformation in the same direction, so it can greatly reduce the elastic compound of the workpiece.
Second, measures to prevent bending crack
1, to prevent bending cracks first of all, we must be strict on the material requirements, to ensure that the surface is free of defects, good quality, if there are defects in the blank should be in the bending of the money to remove, otherwise the bending will be in the defects of cracking.
2, in the design of the bending parts, should make the workpiece bending radius is greater than its minimum bending radius, to prevent bending due to the degree of deformation is too large cracks.
3, bending, the bending line should be as perpendicular to the fiber direction of the material. For the need for two-way bending of the workpiece, the bending line should be as far as possible with the fiber direction at an angle of 45 degrees.
4, bending and burr will cause stress concentration and cracking of the workpiece, so there should be a burr in order to be placed on the inside of the bend.
Third, to overcome the cheap measures
1, in the mold design using pressure device, so that the blank in the state of compression component bending forming, which not only prevents the blank from sliding, and can get the bottom of the workpiece is flat.
2, to design a reasonable positioning plate or positioning pins to ensure that the blank in the mold positioning is reliable, for some bending parts, process holes and pressure plate can be used both.
3, the formulation of technology programs, can be bent pieces of asymmetric shape into a symmetrical combination of shapes, which can ensure that the blank in the bending of the force uniformity, and then cut, is conducive to preventing the generation of offset.
