Precision stamping can do these points, and the pass rate can reach 98%. Let Dongguan Hardware tell you.

Precision stamping achieves the following points, and the pass rate can reach 98%: 1. Precision stamping requires the use of precision stamping molds. The stamping parts obtained by general stamping dies, the shear surface has collapsed corners, fracture zones and burrs, and obvious The dimensional accuracy of the taper is generally low, and the surface roughness Ra is 6.3~12.5um. When there are higher requirements for the section quality and dimensional accuracy of the blanking parts, such as the dimensional accuracy of IT6-7 and the surface roughness Ra of 0.4 to 0.8um, the methods of refurbishment, negative clearance stamping, upper and lower stamping and ring gear pressing plate precision stamping methods can be used produce. Refurbishment is to use a refurbishment die to scrape away thin chips along the outer edge or inside the hole of the stamping part, so as to obtain a smooth and vertical section and accurate size. When punching with negative clearance, the size of the punch is larger than the die ruler, and the direction of the cracks in the punching process is opposite to that of ordinary punching, forming an inverted cone-shaped blank. When the punch continues to press down (note that the punch cannot enter the concave mold), the inverted cone blank is pressed into the concave mold, which is equivalent to a refurbishment process, but the essence of the negative gap stamping method is a composite process of blanking-refurbishment. The up-and-down stamping method uses two punches to stamp from the top and the bottom twice. The stamping parts can obtain two bright bands and can solve the burrs. The essence of the precision stamping of the ring gear plate is the plastic deformation of the material under the three-directional compressive stress state during the entire punching process, which suppresses the occurrence of cracks and tears, and the obtained stamping parts have a smooth cut surface, small taper, smooth surface, and size. The tolerance level is high. Second, precision stamping should avoid tearing of stamped parts. In order to prevent the material from tearing during the stamping process and ensure the progress of the plastic deformation process, the following measures have been taken: 1. The material is pressed with a v-shaped tooth blank holder. Avoid bending and uplifting of the sheet material; 2. Use a small punching gap. The double-sided stamping gap of fine blanking is about 1%-1.5% of the material thickness, so that the material is always perpendicular to the stamping direction, so as to reduce the bending deformation in the deformation zone, and no tensile stress is generated, which constitutes the condition of compressive stress and plastic deformation; 3. Using the blank holder force and the back pressure of the ejector pin, the material deformation zone is tightly compressed to make it in a two-way compression state, and the hydrostatic pressure of the material in the deformation zone is increased to improve the fin property of the material and inhibit cracks and tearing. produce. The cutting edge of the concave or convex mold is made into a small fillet, the radius of which is generally 0.05mm~0.1mm, in order to reduce the stress concentration at the cutting edge and avoid or delay the generation of cracks. Third, precision punching should use precision punching. The precision punching process requires the equipment to provide punching force, blank holder force and counter-top force at the same time, which is usually carried out on a dedicated fine-blanking press. Ordinary presses generally cannot provide these three forces and their movements at the same time, and the rigidity and movement accuracy of the press are relatively poor. Therefore, it is not suitable to perform precision stamping on ordinary presses unless certain technical measures are taken, such as installing machinery. Or the hydraulic device can provide blank holder force and back pressure to realize fine blanking on a general press. The hydraulic device is used to provide the blank holder force and the counter top force, and the pressure is balanced and balanced. The pressure can be maintained or decompressed during the fine blanking process according to the process requirements. The control is simple. Therefore, the fine blanking technology on the ordinary press has the blank holder force and counter The pressure is generally realized by hydraulic pressure. Fourth, the die gap of precision stamping should not be too large. Small gap is the main feature of precision stamping die. The size of the gap and its uniformity along the periphery of the cutting edge directly affect the quality of the shear surface of the fine blanking part. The fine blanking gap mainly depends on the thickness of the material, and is also related to the stamping profile and the material of the workpiece. The gap is too large, and the shear surface is torn. This is because the gap is too large, the material in the deformation zone is subjected to greater stretching, and tensile stress is generated. The tensile stress is the cause of microcracks and tears. Therefore, the gap between the convex and concave molds of precision stamping should not be too large. Big.