Industry News

What are the four major points to pay attention to when maintaining the metal stamping continuous die during hardware processing?

2022-12-26

Hardware stamping is a process that uses punch and die to deform or fracture stainless steel, iron, aluminum, copper and other plates and dissimilar materials to a certain shape and size. Metal stamping is sometimes called sheet metal forming, but it is slightly different. The so-called sheet forming refers to the use of plates, thin-walled tubes, thin sections, etc. as raw materials. The forming method of plastic processing is generally called sheet forming. At this time, the deformation in the direction of thick plate is generally not considered. Maintenance of metal stamping continuous die during hardware processing is as follows:

Hardware processing

1. Maintenance of punch and die

When disassembling the punch and die, pay attention to the original condition of the die, so that it can be easily restored during subsequent mold installation; If the gasket is added or displaced, the thickness of the gasket shall be engraved on the part and recorded.

When replacing the punch, try to check whether the female die of the stripping block is smooth and whether the clearance between the plug and the female die is even; When replacing the female die, check whether the clearance between the insertion and the punch is even.

If the punch becomes shorter after grinding and needs to be padded to the required length, check whether the effective length of the punch is sufficient. To replace the broken punch, find out the cause, and check whether the corresponding die has a broken edge and whether it needs to grind the edge.

When assembling the punch, check whether the clearance between the punch and the fixed block or the fixed plate is sufficient, and if there is a pressure block, check whether there is movement allowance. The assembled female die shall be placed horizontally, and then the flat iron block shall be placed on the female die surface, and the copper bar shall be used to knock it gently in place. It is not allowed to knock it forcibly at an angle, and the bottom of the female die shall be chamfered. After installation, check whether the concave die surface is flush with the die surface.

After the assembly of the male die, female die and die core, it is necessary to check the care belt, whether the parts are installed incorrectly or reversely, whether the female die and female die cushion block are installed reversely, whether the blanking hole is blocked, whether the new parts need to steal materials, whether the materials need to be stolen are enough, and whether the parts that need to be locked are locked.

Pay attention to confirm the locking of the stripper plate screws. When locking, the force should be balanced from the inside to the outside and the screws should be locked crosswise. Do not lock one screw first and then another screw to avoid tilting the stripper plate, leading to punch fracture or lower mold accuracy.

2. Maintenance of stripper plate

The stripper plate can be removed by prying it up with two elevators and then by balancing with both hands. In case of difficulty in disassembly, check whether the inside of the mold is cleaned, whether all the locking screws are disassembled, and whether the mold is damaged due to clamping. Find out the cause and then do the corresponding treatment. Do not blindly dispose.

When assembling the stripper plate, first clean the punch and stripper plate, add lubricating oil at the guide post and punch guide, put them in steadily, then press them in place with both hands, and repeat several times. If it is too tight, find out the cause (whether the guide pillar and guide sleeve are guided normally, whether each part is damaged, whether the new punch can pass through the stripper plate smoothly, and whether the position is correct), and then handle it accordingly.

If there is a pressure block on the fixed plate, check whether there is enough space on the stripping back plate. The material contact surface between the stripper plate and the female die is stamped for a long time to produce indentation. When the indentation is serious, it will affect the pressing accuracy of the material and cause abnormal instability of the product size. The stripper insert and stripper plate need to be repaired or reground.

The contour sleeve shall be checked for accuracy. Unequal height will cause the stripper plate to tilt, and its precise guidance and stable spring compression function will be damaged, so it must be maintained.

3. Adjustment of die clearance

The positioning hole of the die core is worn due to frequent and repeated combination of the die core, resulting in large clearance after assembly (looseness after assembly) or uneven clearance (positioning deviation), which will cause the shape of the section after punching and cutting to become worse, the punch is easy to break, and burrs are generated. Proper clearance adjustment can be made through the inspection of the section after punching and cutting.

When the gap is small, the section is small. When the gap is large, the section is large and the burr is large. The reasonable gap is obtained by shifting. After adjustment, proper records shall be made, or marks can be made on the edge of the die for subsequent maintenance.

In daily production, attention should be paid to collecting and saving the tape when the original mold is in good condition. If the subsequent production is not smooth or the mold has a variation, it can be used as a reference for mold maintenance.

In addition, check and maintain the auxiliary system, such as whether the ejector pin is worn, whether it can eject, and whether the guide pin and bushing are worn.

4. Guide part inspection

Check the fit clearance of the guide pillar and guide sleeve, whether there is burn or wear trace, and whether the oil supply of the die guide is normal.

The wear of the guide parts and the damage of the precision will reduce the precision of the mold, and problems will occur in various parts of the mold. Proper maintenance and regular replacement must be carried out. Check the accuracy of the guide part. If the guide pin is worn and has lost its proper accuracy and function, it must be replaced. Check the condition of the stripper spring and ejector spring to see if they are broken or if they have been used for a long time but have lost their original strength due to fatigue. They must be maintained and replaced regularly, otherwise, they will cause damage to the mold or the production will not be smooth.