1. What is the function of drawing sill (drawing rib) in panel die?
The function of drawing sill (drawing rib) is as follows:
(1) Increase the feed resistance, make the surface of the drawing part bear enough tension stress, improve the stiffness of the drawing part and reduce the defects such as concave surface, distortion, relaxation and ripple caused by springback.
(2) To adjust the flow of materials so that the flow resistance of each part in the drawing process is uniform, or the amount of material flowing into the die is suitable for the needs of all parts of the workpiece, so as to prevent the phenomenon of “more wrinkles, less cracks”;
(3) Expanding the adjustment range of blank holder force. On the double-action press, adjusting the four angles of the outer slider can only roughly adjust the blank holder force, and it can not completely control the feed amount everywhere just in line with the needs of the workpiece, so it also needs to rely on blank holder and drawing rib to assist in controlling the pressure everywhere.
(5) When the drawing rib is used, it is possible to reduce the requirement for the roughness of blank holder surface, which reduces the manufacturing difficulty of drawing die for large panels, and at the same time. Because of the existence of drawing ribs, the gap between upper and lower blank holder surfaces is increased, the wear of blank holder surface is reduced, and the service life of die is increased.
(5) Correct the defect of material irregularity and eliminate the possibility of slip. Because when the material fluctuates through the drawing rib and then flows into the die, it is equivalent to the role of roll leveling.
2. What is the role of process notches in large panels?
When some deep local protrusions or bulges need to be punched out on the middle part of the panel, the local breakage of the workpiece is often caused by the inability to get material supplement from the outside of the blank in one drawing. At this time, it can be considered to punch out the process notch or hole at the appropriate location of the local protrusion deformation zone, so that the easily fractured area can be supplemented by material from the inside of the deformation zone.
3. How to cut the technological incision?
There are two kinds of stamping methods for artistic notches:
(1) When blanking, this method is used in the case of shallow local forming depth.
_Cutting out is a common method in deep drawing. It can make full use of the plasticity of material, i.e. the radial extension of material at the beginning of deep drawing, and then cut out the technological incision. By means of tangential extension of the material, a larger forming depth can be obtained. In the process of deep drawing, the tearing process is often used, which does not completely separate the material. The waste of the incision can be removed in the later trimming process. Otherwise, it will be difficult to remove the waste from the die.
4. What are the layout principles of process incisions?
(1) The incision should be adapted to the shape and contour of the local protuberance in order to make the material flow reasonably.
(2) There should be enough lapping edges between the incisions to tighten the punch material, to ensure clear forming and avoid corrugation, so as to ensure good flanging edge quality after trimming.
(3) The cut-off part of the incision (i.e. the opening) should be adjacent to the edge of the protrusion or the area prone to rupture.
(5) The number of incisions should ensure that the material deformation tends to be uniform in all parts of the protrusion, otherwise it may not necessarily prevent the appearance of lines. As shown in the following figure, the original design only had two process notches left and right, resulting in cracks in the middle, and then added the middle notch (dotted line shown) to completely eliminate the phenomenon of rupture.
5. What precise progressive dies must be used in stamping production?
In large-scale stamping production, multi-position precision progressive die must be used for small and medium-sized stamping parts with thinner materials and higher precision. For larger stamping parts, it is suitable for stamping of multi-station transfer die.
6. What are the requirements for vulnerable parts in precision dies?
Precision die has complex structure, high manufacturing technology requirements and relatively high cost. In order to ensure a higher life of the whole die, it is particularly required that the die parts be replaced quickly, conveniently and reliably after being damaged or worn out. Therefore, the important parts of the die are required to be interchangeable. The die parts with interchangeable properties can be called interchangeable punching die.
7. What is the significance of layout design of precision progressive die?
Answer: Reasonable layout design can make the processing of the die coordinated, can greatly improve the utilization rate of materials, manufacturing accuracy, productivity and die life, but also reduce the manufacturing difficulty of the die. Therefore, layout design is the most critical comprehensive technical problem in the design of precision progressive dies. In order to make layout more reasonable, it is necessary to analyze and judge the stamping direction, the number of deformation, the corresponding degree of deformation, the possibility of die structure and the processing technicality.
8. What is a carrier?
When the progressive die is working, the object that carries the blank to various workstations for blanking and forming is called carrier. The part between the carrier and the blank is called lap, and the part between the blank and the blank is called lap. When working, in dynamic processing, the carrier is required to keep stable and accurate feeding position all the time, so the carrier is required to have certain strength.
9. What is the requirement of the precise progressive die for the die base?
M precision progressive die requires high strength, rigidity and precision. Therefore, structural steel is usually used as the die base. Its thickness is required to be thicker than the standard die base. The thickness of the upper die base is 5-10 mm, and the thickness of the lower die base is about 10-15 mm.
10. What types of die structure are there?
The common types of die structure are integral. Block type and block type three blocks, in ordinary punching
