Improve the stability of the mold have know-how
The main factors affecting the stability of the mold and stamping are: the use of mold materials; mold structural parts of the strength requirements; stamping material properties of stability; material thickness of the fluctuation; material changes in the scope; ; Blank holder force range; lubricant selection. In the stamping process, because each stamping sheet has its own chemical composition, mechanical properties and stamping performance is closely related to the characteristics of the value of stamping material properties of instability, stamping material thickness fluctuations, and stamping material changes, Not only a direct impact on the precision and quality of the stamping process, may also lead to damage to the mold. Take the tensile bar, for example, in the stamping will occupy a very important position. During the stretch forming process, the forming of the product requires a certain amount of tension, which is distributed along the fixed periphery, from the force of the punching device, the deformation resistance of the edge portion material, and the flow resistance on the blank holder face . The flow resistance, if only rely on the role of blank holder force, the mold and the friction between the material is not enough. To this end, there must be set in the blank holder ring can produce greater resistance to the tensile tendons to increase the resistance of the feed, so that the material has a greater plastic deformation, in order to meet the plastic deformation of plastic materials and plastic flow requirements. At the same time, by changing the size and distribution of the tensile bar resistance and controlling the speed of the material flow to the mold and the feeding amount, the tensile force and its distribution in the deformation area of the tensile member can be effectively adjusted, Forming the product rupture, wrinkling, and deformation and other quality problems. Therefore, in the development of stamping process and mold design process, we must consider the size of the tensile resistance, according to the range of blank holder force to the layout of the tensile tendons and to determine the form of tensile tendons, the deformation of the required deformation and deformation Degree of completion of forming.
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