TEL: 0769-83732155
ADD:143 Dongkeng Keji Road, Dongkeng Town, Dongguan
Time:2022-09-16 14:21:02 Views:
1. Produce stamping waste products
Reasons: low quality of raw materials;
Improper installation adjustment and use of press die;
The operator does not feed the strip material correctly along the positioning or does not ensure that the strip material is fed according to a certain gap;
The die is used for a long time, the gap changes or its working parts and guide parts wear;
Due to the impact vibration time is too long fastening parts lose so that the installation position of the punch die relative changes;
Operator's negligence, not according to the operating procedures.
Countermeasures:
The raw materials must conform to the specified technical conditions;
The process procedures specified in each link should be fully and strictly complied with;
The press, dies, and other tooling equipment used should be guaranteed to work under normal working conditions;
A strict inspection system has been established in the production process. The first piece of stamping must be comprehensively checked, and only after qualified inspection can it be put into production. At the same time, inspection should be strengthened, and accidents should be handled in time.
In the process of stamping to ensure that the mold cavity is clean, the workplace is to be organized after processing the workpiece to be placed neatly.
2. Burr of punching parts
Reason: the blanking gap is too large, too small, or uneven;
The cutting edge of the working part of the die becomes blunt;
Punch and concave die due to long-term vibration impact and the center line changes, the axis does not coincide, producing a single burr.
Countermeasures:
Ensure the processing accuracy and assembly quality of concave and convex die, ensure the vertical punch and bear lateral pressure, and the whole die has enough rigidity;
In the installation of punch must ensure the correct clearance of concave and convex die and the use of concave and convex die in the mold fixed plate is installed firmly, the upper and lower die to keep parallel to the work surface of the press;
It is required that the rigidity of the press is better, the elastic deformation is small, and the accuracy of the rail and the parallelism between the pad and the slider are high.
The press is required to have enough punching force;
The height of burr allowed in the shearing section of blanking parts;
Blanking plate thickness > 0.3 > 0.3-0.5 > 0.5-1.0 > 1.0-1.5 > 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 and deformation of punching parts
The reason:
An interstitial force and a reaction force are not in line to produce a torque. (When the clearance of concave and convex die is too large and the cutting edge of the concave die is with reverse taper, or the contact area between the ejector and the workpiece is too small to produce warping deformation)
Countermeasures:
The blanking gap should be selected reasonably;
In the mold structure should be increased pressing plate (or supporting plate) plate and pressing plate plane contact and have a certain pressure;
Check the cutting edge of the concave die if it is found that there is a reverse taper, the cutting edge of the die must be trimmed properly;
If the shape of the blanking parts is complex and the shear force increases the pressing force unevenly when the inner holes are large, the strip material is pressed before blanking or a high-precision press is used for blanking.
The plate should be leveled before blanking. If the warping and deformation cannot be eliminated, the workpiece after blanking can be leveled again by the leveling die.
Clean up the loot in the mold cavity regularly, lubricate the surface of the sheet material, and provide a gas and oil hole on the mold structure.
4. The size and shape of the parts are not qualified when bending
The reason:
The rebound of the material causes unqualified products;
Positioner wear deformation, so that the strip positioning is not correct, must be replaced with a new positioner;
In the unguided bending die, when adjusting on the press, the position of the dead point under the slider of the press is not adjusted properly, and the shape and size of the bending part will not be qualified.
The pressing device of the mold fails or does not work at all. The pressing force must be adjusted again or the pressure spring must be replaced to make it work normally.
Measures to reduce rebound:
Select the punch material with a large elastic modulus and small yield point with stable mechanical properties;
Increase the calibration process, using corrected bending instead of free bending;
Before bending, the material should be annealed to soften the cold hardening material;
If the shape deformation occurs in the stamping process, it is difficult to eliminate; Should be replaced or modified punch and concave die slope, and the concave and convex die gap is equal to less than the material thickness;
Increase the contact area between the concave die and the workpiece, reduce the contact area between the punch and the workpiece;
5. The accuracy of the outer edge and inner hole of the blanking parts decreases and the size changes
The reason:
positioning pin, baffle pin and other positions change or friction is too large;
Operator's negligence when feeding left and right before and after deviation;
The size accuracy of the strip is low, too narrow, and too wide feeding is difficult making it difficult to send to the specified place, the strip will be in the guide plate before and after the offset is out of the workpiece hole and shape before and after the position deviation is larger.
6. Crack occurs in the bending part of the bending part
Countermeasures:
The burr on the outside of the bending area is eliminated, which will cause the stress concentration in the area and reduce the bending deformation. Remove burrs from the area;
The burr side is placed on the inside of the curved area;
When bending the workpiece, it is best to make the bending direction perpendicular to the fiber direction of the material (rolling direction);
The bending radius can not be too small, in the case of quality permits as far as possible to make the radius of rounded corners;
The surface of the curved blank should be smooth and clean, without obvious bumps and scars;
When bending, the intermediate annealing tool is used to eliminate the internal stress, and the bending after softening rarely produces cracks;
When bending, the large bending parts must be coated with a lubricant to reduce the friction in the bending process;
7, bending parts in the bending process of migration
The reason:
In the process of bending, the blank slides along the surface of the concave die, which will be subjected to friction resistance. If the friction resistance difference between two sides of the billet is large, the billet will shift to the side with larger friction resistance.
Countermeasures:
The bending parts with the wrong shape are formed by symmetric bending (the bending parts with a single side are cut by two symmetric bending pieces).
An elastic pressing device is added to the bending die so that the blank can be pressed to prevent movement during bending;
The inner hole and shape positioning form is used to make the positioning accuracy.
8. The surface of the bending part is scraped
Reasons and countermeasures:
For the continuous operation of soft materials such as copper and aluminum alloy bending, metal particles or dregs are easy to adhere to the surface of the working part, so that the workpiece has a large abrasion, and even scratches;
When the bending direction is parallel to the rolling direction of the material, cracks will occur on the surface of the workpiece, so that the surface quality of the workpiece is reduced. When bending two or more parts, the bending direction should be ensured to have a certain Angle with the rolling direction as far as possible;
Die fillet radius is too small, the impact marks appear in the bending part. Polishing the concave die and increasing the radius of the concave die fillet can avoid the abrasion of bending parts;
The clearance of the concave and convex die should not be too small, which will cause thinning and abrasion. In the stamping process always check the change of the clearance of the mold:
Punch into the concave die depth is too large will produce parts surface abrasion, so in the case of ensuring not affected by the rebound, should be appropriate to reduce the depth of punch into the concave die;
TEL:0769-83732155 Mr.Liang: 13922956557 Mr.Liang: 13143284617
ADD:143 Dongkeng Keji Road, Dongkeng Town, Dongguan
EMAIL:youhang@youhangkeji.com youqun@188.com
ICP:16076654
COPYRIGHT @ 2016 Dongguan Youhang Hardware Technology Co.,Ltd
SUPPORT:HZ0769