CNC spinning processing technology characteristics

A, CNC spinning processing characteristics  

CNC spinning processing is suitable for small and medium-sized batch production, processing material wall thickness, forming stretch length, processing accuracy, complex shape of the revolving body thin-wall parts.  

Compared with nc spinning, manual spinning technology because of the limited manpower, thick spinning products, and will not be able to process the stamping and drawing process in processing the same thickness of metal forming products, need the processing power of 3 to 5 times that of spinning, so in stamping tensile processing thickness more than 4 mm, 2 mm stainless steel, aluminum 3 mm iron requires large tonnage punch press or hydraulic press.  When the product is in mass production, stamping and stretch forming processing speed will be faster than CNC spinning, unit cost is lower.  For products with large tensile length, tensile stamping forming is easy to crack, and spinning processing single product forming time is very long, usually with oil pressure stretching semi-finished product blank, and then spinning to do the final forming process, the combination of the two processes can greatly improve the production efficiency of the product, and can reduce the scrap rate of the product.  Aluminum and iron products are easy to combine spinning and stretching. Due to the high hardness of stainless steel, the blank formed by stretching is easy to crack through the position of the spinning joint, as shown in the figure.  

CNC spinning machine empty operation precision 0.04mm, due to the influence of spinning process material flow and stress rebound, so that the precision of processed products can not reach 0.04mm, in aluminum, iron, stainless steel three materials, stainless steel spinning product precision is the most difficult to control, with the diameter of 100mm as the benchmark, the diameter accuracy of general aluminum spinning parts can reach 0.1mm,  The diameter accuracy of iron is about 0.2mm, the diameter accuracy of stainless steel is about 0.4mm, the larger the diameter of the product is, the worse the accuracy is, the precision of strong rotation is higher than that of general rotation.  When the assembly precision of spinning parts is required, it can be achieved by finishing machining.  At present, the product series widely used in CNC spinning include lampshade, stainless steel bowl, stainless steel pot, shielding cover, signal reflection cover, signal receiver cover, chemical container, power container, aluminum bucket, stainless steel bucket, Venner tube, fan tuyere, ventilation pipe, funnel, electrical liner, motor protective cover, etc.  CNC spinning process is more suitable for such special customization, small and medium-sized batch processing products.  

Two, the difference and advantage of CNC spinning and manual spinning  

CNC spinning and manual spinning in the product forming process of the movement principle is the same, through the tail top to provide clamping force, driving the sheet and the spindle can turn together, the knife wheel in accordance with the predetermined knife route to the sheet from point to line, from line to surface extension, finally forming.  The difference lies in the path taken by the CNC machine tool to control the tool wheel in the spinning forming process, as well as the gap between the tool wheel and the mold.  Due to the high precision of CNC machine tools, equipment rigidity, processing force, so the product consistency is good, stable production, and can control the accuracy of products;  And manual in the spinning process, by the manual control of the knife rod to determine the knife wheel to go the knife path, knife path and gap between each product are different, resulting in batch product accuracy is not stable.  

When the thickness of the spinning sheet exceeds a certain range (iron more than 1.2mm, aluminum more than 1.5mm, stainless steel more than 1mm), the manual strength can not support the required processing force when spinning, it is easy to cause the product scrap.  The surface of the outer wall of thin aluminum and iron products processed by hand spinning will be better than the surface of CNC spinning.  But in recent years, after continuous improvement of CNC spinning technology, the outer wall surface of spinning products has been very similar to manual spinning.  

Three, spinning processing and stamping and drawing processing differences and advantages  

Spinning forming and stamping stretch forming can make the sheet forming, the specific differences and advantages are as follows:  

Principle difference: spinning forming is by the path of the knife wheel to control the flow and deformation of the sheet, and the stretch stamping process is through the upper and lower convex and concave die with control sheet flow.  

Mold difference: do the same hardware molding products, spinning molding only need to make a core die, and drawing stamping molding need to make two convex and concave die, die manufacturing cost is usually 3-6 times of spinning, at the same time, the manufacturing cycle of spinning die is shorter than the production cycle of drawing stamping die, size is easier to modify.  

Material difference: spinning process thinning rate is usually about 30%, tensile stamping process thinning rate is about 10%, the thinning rate is relatively larger, and tensile stamping needs about 5-10mm blanking material, the required material cost is large.  

Processing difference: for some simple hardware molding products, the tensile stamping forming process, including the basic working procedure such as cutting, forming, trimming, some products molding process after a lot of stretching, various process but relatively faster processing speed, and the spinning forming and cutting can be done on a CNC spinning machine at the same time, but the single processing speed will be slow;  For some products with long stretch height or irregular shape, stretch stamping will lead to product cracking, but spinning is easier to complete the product forming.  

Product difference: in the surface of the product, spinning pattern is a circle distribution, stretching mark is a vertical distribution;  In terms of the strength of the product after molding, the strength of the spinning product will be much better than the strength of the tensile stamping.  

Aluminum, 2mm stainless steel, 3mm iron need a large tonnage of punch or hydraulic press.  When the product is in mass production, stamping and stretch forming processing speed will be faster than CNC spinning, unit cost is lower.  For products with large tensile length, tensile stamping forming is easy to crack, and spinning processing single product forming time is very long, usually with oil pressure stretching semi-finished product blank, and then spinning to do the final forming process, the combination of the two processes can greatly improve the production efficiency of the product, and can reduce the scrap rate of the product.  Aluminum and iron products are easy to combine spinning and stretching. Due to the high hardness of stainless steel, the blank formed by stretching is easy to crack through the position of the spinning joint, as shown in the figure.