Metal stamping parts of two big failure analysis

Metal stamping parts of the two failure analysis stamping is the first of four major technology, its importance cans be imagined. Stamping factory to the quality of the finished goods to the vehicle appearance and performance to lay a reliable foundation, therefore, stamping parts quality assurance has been auto manufacturing enterprise attaches great importance to the problem. A, metal stamping parts why turn material distortion? In progressive die stamping, die-cutting stamping surrounding by remaining material method, to form the appearance of salt pieces. Salt pieces turn makings, distortions of the main reason for the influence of cutting force. Blanking, as a result of the existence of blanking clearance, material in the side of the concave die drawing ( Material up warping) , rely on the convex side by compression. When using stripper plate, using the stripper plate clamp material, to prevent the side of the die material up warping, at this point, the stress of the material of the corresponding change. With the increase of the unloading slabs the blank material force, rely on the convex side of material by the tensile ( Compression force decreases) Material and die surface compression ( Tensile strength decreases) 。 Stamping parts as the flip of material on the surface of the concave die caused by stretching. So when cutting, pressure and pressure material is prevent salt pieces turn makings, the key point of distortion. When bending stamping the causes and countermeasures of double material and torsion: 1 cutting salt pieces of burrs. To research cutting edge, and pay attention to check whether the blanking clearance is reasonable. 2 blanking has washed pieces of double material and torsion deformation, lead to bad after bending forming, blanking blanking from location to tackle. 3 when bending instability caused by pressing. Mainly aimed at the U and V bending. Deal with the problem of stamping parts before bending of guide, the guide, in the process of bending and bending process of medium pressure live material prevent stamping when bending slide is the key to solve the problem. Second, metal stamping parts cause why tears? Metal stamping parts among common forms of tear, askew protective stent stamping process: blanking punching - - Punching cut - - Flanging forming - - Notch - - Flanging. Tear in intermediate casing bracket forming, skewed in a variety of forms, the torn part mainly distributed in the pass of the parts, wall corner R arc and wall, such as the neck border because of difference of stamping and production process conditions, the proportion of the fractures are different. Tear tear can be one-time forming, also can be caused by fatigue crack is invisible crack development. Cause analysis of that, according to the actual situation, by examining the torn part of fabrication, fracture morphology and crowded degree of injury, thought to cause tearing parts, deflection behavior mainly embodied in the flange forming process, the causes of this process occurs as follows: 1. Implementation does not reach the designated position, forming process parameters in the process of stamping forming, technological requirements material core die, pressure and both parts must fit closely together, in the machine tool slide block slide compression forming sheet metal plastic deformation and implementation. But now due to suppress the unsteady quality defects of parts, means that the pressure in the process of production machine tool in the beating pressure imbalance state. Investigate its reason, mainly processing technical personnel not according to process requirements specified in this one phase in a timely manner to adjust machine pressure, every shift or in transition, no mutual communication machine pressure stability information, causes the product quality is not stable. 2. Flanging forming mould design flaws, this mould for a double cavity left/right public, due to this process content in addition to the flanging, also have both shape forming content, combined with the special complex parts, curved surface is narrow, the forming requirements concave die core material consistent with the forming surface and so on, cause mould structure conditions for forming large travel, pressure area is small. Designers in the original die design, only consider the small pressure is expected to face this feature, but neglected the material core forming guide slide stroke. According to my company stamping quality management experience, the author summarizes the common problems in the process of metal stamping parts products production reason and countermeasures, hoping to improve on the quality of stamping parts factory counterparts to provide some useful reference.