Maintenance of progressive die and elimination of common faults 1

1 Mold Maintenance Tips
The maintenance of the progressive die must be careful, patient, and step-by-step, and must not be blindly engaged. When removing a mold due to a fault, it is necessary to attach a material tape for the inquiry of the problem. Open the mold, check the tape, check the condition of the mold, confirm the cause of the failure, identify the problem, clean the mold, clean the chips, etc., before removing the mold. When removing the mold, the force should be uniform. For the unloading spring in the mold structure between the upper die (fixed) plate and the stripper plate, the removal of the stripper plate should ensure balanced ejection. Tilting of the stripper plate may cause the die to break.
1.1 Maintenance of Male and Female Dies
When the male and female dies are disassembled, they should pay attention to the original state of the dies so that they can be easily restored during subsequent loading. When replacing the punch, you should see if the ejector plate is smooth. When the total length of the punch after maintenance is shortened and a spacer is required to reach the required length, it is checked whether the effective length of the punch is sufficient. When using a new punch or die insert, pay attention to the handling of the clear corners. Because of the wear of the grinding wheel in the concave corner, there will be a smaller R, and relative to the convex position, it is necessary to artificially repair R, so that the fit clearance is reasonable. More attention should be paid to the small protruding parts. Replace the broken punch, should check the reason, and at the same time to check whether the die has caused a chipping, is not required grinding edges.
Assembly die should be placed horizontally, and then use a flat iron placed on the core with a copper rod to gently knock it in place, must not be tilted by strong knock (if necessary, in the core bottom corner Pour out R for easy introduction. If the force is not uniform during assembly, add spacers under the die should be flat, generally no more than two (and as much as possible using steel pads), otherwise it will easily lead to fracture or forming of the die Unstable dimensions (especially bending). After the punch and mold cores are assembled, they must be inspected with reference to the tape. Whether the wrong parts are installed or reversed, check whether the core of the mold is flipped or not. After confirming that there is no error, the board can be loaded or unloaded. Take care to confirm the locking of the stripper plate screws in order to obtain sufficient locking force. When locking, it should be interlocked from the inside to the outside, and the force should be cross-locked. Do not lock one screw at a time and lock the other one at a time. Otherwise, the punch may break or the precision of the die may be reduced.
1.2 Maintenance of Stripper Plates
The disassembly of the stripper plate can be balanced with two drivers, and then the force can be taken out by balancing them with both hands. When it is difficult to disassemble, check whether the mold is clean and whether the locking screw has been completely disassembled, and whether the mold is damaged due to card material. Find out the reasons and deal with them accordingly. Do not blindly dispose of them. When assembling the stripper plates, first clean the punch and stripper plates, add lubricant to the guide column and the punches, and place them in a smooth place. Use rubber tweezers or copper rods to knock them into place. Press in place with both hands and repeat several times.
If it is too tight, you should check the reason: whether the guide column and guide sleeve are normal, whether there is any damage on the parts, and whether the new replacement part has been properly treated (such as whether the punch is chamfered, whether it can pass through the stripper board, etc.) , find out the reasons, and then make appropriate disposal. The material contact surface between the stripper plate and the die is stamped for a long time to produce an indentation (The gap between the stripper plate and the die is generally 0.03-0.05mm thick. When the indentation is severe, it will affect the compression of the material. Accuracy, resulting in product size anomalies, instability, etc., need to repair or regrind the plate inserts and stripper plates. Contour sleeves should be checked for accuracy, it will lead to the tilting plate, its precision Guided, smooth resilience will be destroyed and must be maintained.
 1.3 Directional Inspection
Whether the guide posts and guide bushes are fitted with clearances, whether there are burns or wear marks, and whether the mold-guided oil supply status is normal should be checked. The wear of the guides and the destruction of the precision will reduce the accuracy of the molds, and problems will occur in various parts of the molds, so proper maintenance and regular replacement must be performed. (to be continued)

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