In the process of metal stamping, especially punching, we often encounter the phenomenon of punching needle fracture. In this kind of problem, metal stamping manufacturers often replace the new punching needle directly, but can not fundamentally solve the problem of punching needle fracture. Below we analyze the common causes and solutions of the punching needle fracture in the stamping process:
1) The generated waste will block the lower mold.
Solution: Modify the blanking hole, so that the waste can fall smoothly.
2) The fixed part (splint) and guide part of the injection needle
Solution: Repair or re-wire cut into the block to make the needle up and down smoothly (return plate) offset
3) The closing height of the stamping die is set too low, resulting in too long the part where the punching needle enters the lower die.
Solution: Adjust the closing height of the punch press, so that the amount of punch needle into the lower die is appropriate.
4) The design of the withdrawal plate is unreasonable, resulting in uneven force of the punching needle.
Solution: Redesign the clearance between the discharge plate and the punching needle.
5) The design of the punching needle blade is too short, and it will collide with the discharging plate at work.
Solution: Re-select the appropriate punch needle, or increase the length of the edge section.
6) There are strains and scratches on the surface of the punching needle, and the force of the punching needle is not uniform when the material is returned.
Solution: Replace the needle with a new one.
Metal stamping parts
7) The edge of the punching needle is worn and the edge becomes blunt.
Solution: Re-repair grinding needle blade.
8) The selected punching needle is too thin, too long or not strong enough.
Solution: Need to choose another type of punch needle.
9) The hardness of the punching needle is not appropriate, and the selected punching needle material is not appropriate.
Solution: Change the appropriate punching needle material, or heat treatment.
10) The design of the mold positioning device is not reasonable, resulting in only one side of the punching needle, so that the force of the punching needle is not uniform.
Solution: Adjust the mold positioning device so that the needle can cut the complete material when punching.
11) The stamping needle is not fixed firmly enough, and shaking occurs in the stamping process.
Solution: Reattach the needle so that it can’t move up or down.