Hardware mold, how to improve material utilization
Material size optimization
Reduce blank size
By adjusting the positioning of blank sheet material in drawing die, the process supplement of surplus material other than drawing bar is reduced, so as to reduce the size of blank sheet material required by parts and improve the utilization rate of materials.
Figure 5 for T/B model beam parts below the window before the wind, in drawing forming transition observed, drawing a process added area and a large part of the blank sheet has not been effective utilization, by measuring, the parts of an open-book step distance from 590 mm to 560 mm, and the drawing mould research and adjust sheet positioning device, after three coordinate measuring geometry appearance inspection and confirmed: in the case of sheet metal step reduced from 30 mm, normal parts forming, quality conforms to the standard.
The material utilization rate of the lower beam of the front wind window of model T/B was improved by 2.4% after the blank size optimization. hardware mold
The steel mill has a certain control range for the thickness tolerance of the product when producing steel coils and steel plates. Table 1 is the control standard for the size of coils.If the thickness of the steel coil is to press are tolerance for delivery to the factory, the open book out the blank sheet thickness will be within the scope of the qualified partial thick, will cause the blank sheet metal and stamping parts weight is higher than the actual weight process ration, and on the other hand, will cause the coil open book out of the actual sheet quantity is less than the theoretical quantity, which reduces the yield.R33 top cover parts, for example, blank sheet specifications of 0.8 mm * 1150 mm * 1680 mm, material grades for DX54D + Z, its material with three suppliers, material tolerance dimensions of three suppliers are within the scope of the qualified, but by tracking, one of the material after each uncoiling of the actual quantity of sheet metal are less than number theory, and the other two steel roll material after uncoiling of the actual quantity of sheet metal are slightly higher than the number theory.R33 cover parts process consumption quota is 11.993kg.In theory, a 10t heavy steel coil can be unrolled and R33 cover material is 10000kg/11.993kg=834 sheets.According to table 1 standard, R33 roof parts using DX54D + Z material yield strength is less than 280 mpa, coil width is 1150 mm, less than 1200 mm, so the most thin and thick sheet thickness difference of 0.06 mm, is a 10 t steel coil can open book out of the last and the other sheet number 996 and 771 respectively, and the difference of 125 pieces, in the case of the negative tolerance delivery, compared are tolerance delivery material utilization increased by 15%.Therefore, steel mills are required to adopt negative tolerance for steel coil delivery, which can significantly increase the number of blanks and improve the material utilization rate.
Waste collection and reuse
Some parts in the uncoiler blanking, will produce a large area of unused waste, the waste will be used in the production of other small parts of the car body, can avoid the small parts of the material used in separate procurement, saving the cost, but also improve the material utilization rate of the vehicle.
Figure 6 shows the inner plate material of R33 rear wing plate, whose coil size is 0.7mm ×1275mm. There is waste material when uncoiling.The plate size of the front cover plate parts is 0.7mm×445mm×1070mm, and the consumption quota is 2.594kg. The two parts have the same material brand. By collecting the waste of R33 rear wing plate uncoiling step for production of front cover plate parts, the material utilization rate is increased by 13%.
The scrap of R33 side enclosure plate was collected by a similar method. The coil size was 0.85mm×1450mm, and the material brand was DX56D+Z.R33 about the front part of rear wheel cover, the size is 0.8mm×930mm×254mm, the material brand is DX56D+Z.By collecting the waste generated by R33 side coiling and manually pruning the waste, the rectangular plate obtained can be used to produce the rear wheel cover parts around R33, and the material utilization rate is improved by 8%.
Very high roll weight, reduce head and tail waste
The stamping process flow is provided by the material supplier with packaged rolls. After unpacking, the rolls are cut into various shapes needed by the uncoiling equipment, and then various parts are stamped out.When uncoiling, it is necessary to shear the outer ring and inner ring of the coiling material, and at the same time, the head and tail of the coiling material need to pass through the uncoiling equipment. The normal production loss is about 15m at the end of the head and tail of each coiling material.Therefore, the larger the uncoiling batch, the heavier the average weight of the coil, the higher the uncoiling efficiency, and the less the average loss of the coil.Overall x side plate material cycling around 60 kg, stamping uncoiling line batch big, tracking its lateral confining material coil weight, volume weight distribution of 7 t to 15 t, the average weight of about 10 t, through calculation analysis, if the coil weight up to 18 tons, each batch of uncoiling line would be less a volume of material production, is less a coil head material end processing, lateral confining material utilization can be improved by about 1%, open-book efficiency is about 5%.According to the equipment capacity and transportation conditions, the requirements of coil weight are proposed to the steel mill. At present, the average coil weight of this side girth material is 18.5t, and the utilization rate of coil material converted into sheet material is increased from the original 98.2% to 99.2% (sheet material conversion rate = net weight of coil material/consumption quota ×100%).
For stamping parts, material utilization of the same parts reflect the technological level and the level of technology of stamping combining with actual application, from process optimization, material size optimization, waste recycling, coil weight to improve material utilization to improve automobile stamping parts are introduced in aspects of method, through the practical application of the above methods, improve the technology, technical level, to provide good reference for subsequent project process design.Method to improve the utilization ratio of material a lot, more methods need to verify through practice, such as punching blanking, covering parts existing line instead of a knife or circular knife knife, wave by changing the shape of the slab, shorten the slab length, thus improve the material utilization, this method requires accounting tooling investment, maintenance cost and improve the material utilization of benefit relations.In a word, to improve the material utilization rate is to reduce the complete cost of the vehicle. When making a plan to improve the material utilization rate, it is necessary to consider the relationship between investment cost and income in combination with the model output. hardware mold