The progressive die (also called continuous die) consists of multiple stations, each of which is associated in sequence.
The machining process completes a series of different stamping operations in one stroke of the press. After the completion of one stroke, the punch feeder moves the material forward according to a fixed step, so that multiple processes can be completed on one pair of molds, generally punching, blanking, bending, trimming and deep drawing, etc.
1. Progressive die is a multi-task die. It can include multiple processes such as punching, bending and drawing in a pair of molds, which has high productivity;
2. The progressive die operation is safe;
3. Easy to automate;
4. Can be produced by high speed punching;
5. It can reduce the punching, the area of the site, and reduce the transportation and warehouse occupation of the semi-finished products;
6. Parts with extremely high dimensional requirements should not be produced by progressive die.
2. Large batch size;
4. The material is softer;
6. Valuable metals are not suitable (low utilization);
7. The accuracy is too high (IT10 or below).
What is continuous die?
Continuous die means that the press uses a strip-shaped stamping material in one press stroke, and simultaneously performs a cold stamping die of multiple stamping processes on several molds with several different stations. Move once with a fixed distance until the product is finished.
Whether a stamped part adopts a multi-station continuous mode or not? We should consider the following aspects:
(1) Design, fabrication and maintenance of continuous molds
The structure of the multi-station continuous mode is quite complicated, and the manufacturing precision is much higher than that of the general mold. After each batch production, it must be repaired and sharpened, and after passing the test, it can be put into storage for use. Some small punches must be replaced in time after the insert is worn or damaged. Bending, deep drawing, forming multi-station continuous die, when sharpening the edge of the punch and die, correct the relative height of other parts at the same time. The bending, deep drawing, and forming multi-station continuous die have different heights of the punch and the die, so the relative difference of the original design must be maintained after sharpening. There must be a certain level of maintenance workers and the necessary precision equipment.
(2) Applicable presses
Presses used in continuous mode should have sufficient strength, stiffness, power, accuracy, large work surface and reliable braking system. The stroke of the punching machine should not be too large to ensure that the continuous mold frame guiding system does not disengage when working. Generally, it should work below 80% of the nominal pressure of the press. In the multi-station continuous mode, the detection mechanism of the strip feed failure should be set. After the detection mechanism sends out the signal, the brake system must be able to stop the press immediately to avoid damage to the mold or the machine tool.
(3) Good processed materials
In the continuous die-punching process, intermediate annealing cannot be performed, which is not convenient to increase lubrication during processing. Therefore, the mechanical properties of the stamping materials must be relatively stable. For each batch of materials entering the factory, it must be tested and inspected according to regulations; The width and thickness tolerances of the strip, as well as the straightness of the stock edge, are high because they will directly affect the punching effect and the feed of the strip.
(4) Stamping parts should be suitable for multi-station continuous die-punching
1. The production and batch size of the parts to be processed should be large enough.
2. Multi-station continuous mode is lower in material properties than other molds.
3. The accuracy of feeding and the cumulative error between each step will not reduce the accuracy of the parts.
4. The shape of the part is complicated and it is not easy to position after punching. It is most ideal to use multi-station continuous mode.