The common bad phenomenon and countermeasure of stamping parts
1. Stamping waste is generated
1) Reasons
Poor quality of raw materials;
Improper installation, adjustment and use of the die;
The operator does not correctly feed the strip along the positioning or does not ensure that the strip is fed according to a certain gap;
Due to long-term use of the die, the clearance changes or its own working parts and guide parts wear;
Due to the impact vibration time is too long, the fastening parts are loose, so that the installation position of the punching die changes relative;
The operator's negligence in not following the operating procedures.
2) Countermeasures
The raw materials must conform to the specified technical conditions;
All links stipulated in the process should be fully and strictly complied with;
The tools and equipment such as press and die used should be guaranteed to work in normal working condition;
A strict inspection system has been established in the production process. The first stamping part must be comprehensively inspected and qualified before it can be put into production. At the same time, inspection should be strengthened to deal with accidents in time.
In the stamping process to ensure the cleaning of the mold cavity, the workplace to tidy up the orderly processing of the workpiece to be placed neatly.
2. Blanking parts burr
1) Reasons
Blanking clearance is too large, too small or uneven;
The working edge of the die becomes dull;
Punch and die due to long-term vibration impact and the change of the center line, the axis does not coincide, resulting in single-sided burr.
2) Countermeasures
Ensure the machining accuracy and assembly quality of the die, ensure the perpendicularity of the punch and bearing side pressure and the whole die should have enough rigidity;
When installing the punch, it is necessary to ensure the correct clearance of the convex and concave die and make the convex and concave die firmly installed on the fixed plate of the die. The end face of the upper and lower die should be parallel to the working table of the press;
The rigidity of the press is required to be better, the elastic deformation is small, the precision of the track and the parallelism between the plate and the slider are required to be high;
The pressure machine is required to have enough punching force;
The allowable burr height of the shear fracture section of punching parts:
Blanking sheet thickness > 0.3 & gt; 0.3 0.5 & gt; 0.5 1.0 & gt; 1.0 1.5 & gt; 1.5-2.0
New mold burr height ≤0.015≤0.02≤0.03≤0.04≤0.05
Allowable burr height during production ≤0.05≤0.08≤0.10≤0.13≤0.15
3. Warping deformation of blanking parts
1) Reasons
There are clearance forces and reaction forces not in line to produce torque. (When the gap between the die and the die is too large and the edge of the die has the opposite taper, or when the contact area between the ejector and the workpiece is too small, the warping deformation will occur).
2) Countermeasures
Blanking clearance to choose reasonable;
On the mold structure, the pressing plate (or supporting plate) should be added to contact with the pressing plate plane and have a certain pressure;
Check the edge of the die if there is a reverse taper, the cutting edge of the die must be trimmed properly;
If the shape of the punching parts is complex and the inner hole is more than the shear force increases the pressing force unevenly, press the strip material before punching or use high precision press punching;
The plate should be levelled before blanking, if still can not eliminate the warping deformation can be blanked after the workpiece through the levelling die again levelling;
Regularly remove the stolen goods in the mold cavity, the surface of the sheet material is lubricated, and the mold structure is provided with an oil and gas hole.
