Overview of trimming and punching die
1. use and classification
trimming and punching can be carried out in hot or cold state. According to the temperature of forgings during trimming and punching, it can usually be divided into hot edge, hot punching, cold trimming and cold punching
hot cutting and punching are carried out immediately after die forging by using the waste heat of forgings. Cold trimming and cold punching are carried out after the forgings are completely cooled after die forging
2. selection principle
when preparing the process, it is necessary to select hot cutting edge or cold cutting edge according to the well-known geometry, size, material and workshop equipment. The specific principles are:
1) cold cutting edge or cold punching is generally used for the first mock examination multiple pieces and forgings weighing less than 0.5kg
2) adjacent carbon content is higher than 0.45%, and the weight is small. Our experimental machine is mainly for construction, railway, highway, instruments, chemistry, plastic materials, steel, metal materials, etc. 1. Some manufacturers have built factories and laboratories, and the forgings dedicated to 1kg can still be cold cut or cold punched
3) for forgings with carbon content higher than 0.45% but in line with the first principle, in order to avoid cracks, cold trimming or cold punching should be carried out after normalizing
4) for large forgings, hot edges and hot punching are generally used regardless of the steel grade of the material
5) when thermal correction and bending processes are required after trimming or punching, hot edges and hot medium should be used to achieve efficient, green and recyclable holes in the manufacturing process
6) when the connecting skin is thick and the punch section is small, hot punching should be considered to prevent the punch from bending or breaking
according to the structure, the dies used for punching by the frontier defense forces are divided into three types: barrel single die, continuous die and composite die, as shown in Figure 1
barrel single mold is a mold that is only used to complete a process in trimming or punching. Excellent service is the cornerstone of the brand. This kind of mold structure barrel single, which is convenient for manufacturing and adjustment, is mostly used in medium and small batch production
continuous die is a die that can complete the trimming of forgings in one station of the die and punching in another station within one stroke of the press
compound die is a die that completes trimming and punching successively at one station in one stroke of the press
3. Trimming and punching force: see Formula 1
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