Stability of metal stamping parts production and its influencing factors

What is stability? Stability is divided into process stability and production stability. Process stability refers to a process plan that satisfies the stability of a qualified product; production stability refers to a production capacity with stability during the production process. Since most domestic mold manufacturing enterprises are small and medium-sized enterprises, and quite a few of them are still in the traditional production management stage, they often neglect the stability of the mold, resulting in long mold development cycle and high manufacturing cost. Restricted the pace of development of the enterprise. Metal stamping parts Let us first look at the main factors affecting the stability of metal stamping parts, namely: the use of mold materials; the strength requirements of mold structural parts; the stability of stamping material properties; the fluctuation characteristics of material thickness; the range of material changes; The resistance of the tensile ribs; the range of the blanking force; the choice of lubricant. As is well known, the metal materials used in stamping dies involve many types. Due to the different functions of various parts in the mold, the requirements and selection principles of the materials are not the same. Therefore, how to use mold materials reasonably has become one of the most important tasks in mold design. When selecting the mold material, in addition to the requirement that the material must have high strength, high wear resistance and appropriate toughness, the characteristics and production requirements of the material to be processed must be fully considered, so as to achieve the stability requirements of the mold forming. Metal stamping parts In actual operation, since the mold designer tends to select the mold material based on personal experience, in the metal stamping, there is often a problem that the mold forming is unstable due to improper selection of the material of the mold part. The following is an example [Example] A circular hole having a diameter of 2.8 mm was machined on an iron plate having a material thickness of 1.2 mm (shear strength of 64 kgf/mm2). 1 punching force: P = Ltτ. among them, L: punching profile length (mm); t: thickness of the material (mm); τ: shear strength of the material (kgf/mm2); d: punch diameter (mm); P=3.14×2.8×1.2×64=675kgf 2 Stress of the punch edge: σS = 4tτ / d. That is, σS=4×1.2×64/2.8=110kgf/mm2 Metal stamping parts As shown in the figure above, when the σS is 110kgf/mm2, the punch material is SKD11, and the punch reaches about 9000 punches, the punch edge may be damaged. If the material is changed to SKH51, it is expected to increase the level to about 40,000 strokes. It can be seen that in the mold design stage, it is necessary to carry out the necessary strength check calculation for the mold structural parts, and the following precautions are taken when selecting materials: 1 The stress experienced by the punch