During the stamping process, the punching gap of the stamping die plays a decisive role in the cross-section quality of the part.
When the blanking gap is too large, the cross section of the part will show typical characteristics. The upper and lower cracks cannot overlap, the fracture zone is widened and rough, and large collapse angles and burrs will be produced. This is because the excessive gap causes the material to be significantly stretched during punching, causing the crack expansion direction to deviate from the ideal state, resulting in a serious decline in cross-section quality, and it is difficult to guarantee the dimensional accuracy of the parts, which are often too small.
Too small a blanking gap can also cause many problems. When the material is sheared, it is over-squeezed, and the bright band on the cross section is abnormally wide and thick, while the fracture zone becomes narrow and irregular, and secondary bright bands may even appear. In this case, not only the cross-section quality of the parts is poor, but also the wear of the mold cutting edge is increased. Because the small gap causes the friction between the cutting edge and the material to increase sharply, it is easy to cause the cutting edge to heat up, deform or even be damaged. At the same time, the size of the part may be deviated. big.
Appropriate blanking clearance can achieve better quality of part section. At this time, the upper and lower cracks basically overlap, the width of the fracture zone is moderate, the proportion of bright zones is reasonable, and the collapse angle and burrs are small. Such cross-sectional quality can meet the usage requirements of most parts, making subsequent assembly and surface treatment more convenient.
Material properties have an important influence on blanking gap optimization. For example, for soft and ductile materials, the blanking gap should be relatively small to reduce tensile deformation and ensure the flatness and smoothness of the cross section; for hard materials, appropriately increasing the blanking gap can reduce the mold edge. Oral pressure to prevent the cutting edge from wearing too quickly.
Blanking speed is also a factor that correlates with the blanking gap. During high-speed blanking, the material deforms quickly and the stress state is complex, requiring more precise control of the blanking gap. If the gap is not appropriate, defects such as tearing and deformation will be more likely to occur in the section of the part under high-speed impact.
The mold structure cannot be ignored either. Complex mold structures may lead to uneven distribution of punching force, which requires that the stress of each part of the mold be fully considered when optimizing the punching gap, and methods such as setting gaps in partitions should be used to ensure that the cross-sectional quality of parts at different parts can be achieved. standard.
In-depth study of the impact of stamping die stamping gap optimization on part cross-section quality, comprehensive consideration of materials, blanking speed, mold structure and other factors can determine the most reasonable punching gap, thereby improving the part cross-section quality and extending the use of the mold life, improving the efficiency and quality level of the entire stamping process.
