Metal forming refers to the process of plastic deformation of metal materials by external force, so as to obtain the desired shape and size, and metal stamping is one of the metal forming processes, which mainly uses presses and molds to exert pressure on plates, strips, tubes and profiles, etc., so as to make them separate or plastically deform, so metal stamping can be regarded as an important branch in the field of metal forming, and the two are closely related to each other. Together, they provide efficient means of metal processing for the manufacturing industry. The following are some of the issues that need attention in stamping process design.
First, What is the role of the deep drawing threshold (deep drawing bar)? The role of the deep drawing threshold (deep drawing bar) is as follows.
1, increase the feed resistance, so that the surface of the deep-drawing parts to withstand sufficient tensile stress, improve the stiffness of the deep-drawing parts and reduce the rebound due to concave, twisted, loose and corrugated and other defects;
2, regulate the flow of materials, so that the deep-drawing process in all parts of the flow resistance is uniform, or so that the amount of material flow into the mold is suitable for all parts of the workpiece needs, to prevent “more is wrinkled, less is cracked,” the phenomenon;
3, expand the adjustment range of crimping force. In the double-action press, adjust the height of the four corners of the outer slide, can only roughly adjust the crimping force, and can not fully control the amount of material in each place to meet the needs of the workpiece, so you also need to rely on the crimping surface and deep-drawing rib to assist in controlling the pressure of each place;
4, when the deep-drawing rib, it is possible to reduce the requirements of the processing roughness of the crimping surface, which reduces the difficulty of manufacturing large cover parts deep-drawing mold; at the same time. Due to the existence of deep drawing rib, increase the gap between the upper and lower crimping surface, so that the crimping surface wear is reduced, improve the service life of the mold;
5、Corrects the defect of material unevenness and can eliminate the possibility of generating slippage. Because when the material through the deepening rib to produce undulation and then to the concave mold inflow process, equivalent to the role of roller pressure leveling.
Second, what is the role of the process notch in large cover parts? When it is necessary to stamp out some depth in the middle part of the cover part of the local protrusion or bulge, in a deep-drawing, often due to the outside of the blank can not be supplemented by the material and lead to the local rupture of the workpiece. At this time, can be considered in the local protrusion deformation area of the appropriate location of punching out the process of cutting or process holes, so that easy to rupture the region from the deformation of the internal area of the material to replenish.
Third, how to punch the process notch? There are two ways of punching process for process notch:
1、Punching out during material drop This method is used for occasions where the depth of local molding is shallow.
2, deep drawing process cut out this is a commonly used method, it can make full use of the plasticity of the material, that is, in the beginning of the deep drawing stage to use the radial extension of the material, and then cut out the process of notching. The use of tangential extension of the material, so you can get a greater depth of molding. In the deep-drawing process when cutting out the process hole, often using the process method of tearing, and does not make the material completely separated, the waste of the incision can be removed in the later trimming process together. Otherwise, the difficulty of removing the waste from the die will arise.
Fourth, what is the principle of the arrangement of the process incision? The size and shape of the process notch depends on the area in which it is located and the requirement of supplementing the material to the outside. Generally need to follow the following principles:
1, the incision should be compatible with the shape of the local protrusion contour, so that the material flow reasonably.
2, between the incision should leave enough overlap, so that the convex mold tension material, to ensure that the formation of clear, to avoid ripples and other defects, so as to ensure that trimming can be obtained after a good quality of the flap edge of the hole.
3, the cut part of the cut (i.e. opening) should be adjacent to the edge of the protruding parts, or easy to rupture the area.
4, the number of incisions should ensure that the protruding parts of the material deformation tends to be uniform, otherwise it may not be able to prevent the grain. The following chart, the original design only left and right two process incisions, the results of the middle still produce cracks, and later added the middle of the incision (shown in dotted line), completely exempt from the rupture phenomenon.
Fifth, in which stamping production must be used in precision progressive die? In the large-volume stamping production, thinner materials, higher precision small and medium-sized stampings, must use multi-station precision progressive die. For larger stamping parts, it is suitable for the stamping process of multi-station transfer mold.
Sixth, what are the requirements for perishable parts in precision molds? Precision mold structure is complex, high manufacturing technology requirements, the cost is relatively high. In order to ensure that the whole set of molds have a high life expectancy, especially after the mold parts damage or wear and tear replacement quickly, easily and reliably, so the important parts of the mold is required to have interchangeable, the mold parts have interchangeable nature of the die, can be called interchangeable punch mold.
Seventh, what is the significance of the layout design of precision progressive dies? Reasonable layout design, you can make the mold processing of each station coordinated, can greatly improve the utilization of materials, manufacturing accuracy, productivity and mold life, but also can reduce the difficulty of manufacturing molds. Therefore, the layout design is the most critical comprehensive technical issues in the design of precision progressive die, must be made of the stamping direction, the number of deformation and the corresponding degree of deformation and the possibility of mold structure and processing technology for a comprehensive analysis and judgment, in order to make the layout tend to be reasonable.
Eight, what is called carrier? In the progressive die work, carry blanks to the various stations for a variety of blanking and forming process objects are called carrier. Carrier and blanks connected to the part called lap, blanks and blanks connected to the part called lap. Work, in the dynamic processing requirements carrier always keep feeding stable positioning accuracy, so the carrier is required to have a certain degree of strength.
Nine, what are the requirements of precision progressive die on the die base?M precision progressive die requires high strength, good rigidity, high precision mold. Therefore, it usually adopts structural steel to make the mold base, and its thickness is thicker than the standard mold base, the upper mold base is thickened by 5~10mm, and the lower mold base is thickened by 10~15mm.
Tenth. What are the types of concave mold structure? The common types of concave mold structure are integral type. Block type and embedded block type three, in the ordinary stamping die often choose the standard concave template for the overall concave die, in the precision level for the mold is often used in the block type and embedded block type concave die.
Stamping die visual monitoring can effectively detect the continuous stamping die material belt is transported in place, whether the blockage of material stacking and so on, effectively reduce the pressure die, protect the stamping die, reduce costs and increase efficiency, improve factory automation level; at the same time can be the existence of the appearance of the stamped part of the defects in a timely manner to monitor.