Tel：0512-65685025
Fax：0512-65650370
Email：sales@hanke-nmc.com
Website：http://www.hai-te.cn
Add: Block 7, No.19, Xingnan Road, Wuzhong, Suzhou City, Jiangsu, China
Name：Rebecca Dong
|
|
Technical |
|
 |
Solution of 15 common problems in mold maintenance and repair work. |
1. Attention should be paid before the punch.
Clean the punch with a clean cloth.
Check the surface for scratches and dents. If yes, remove with oil stone.
To prevent rust in time.
Be careful not to have any slant when installing the punch. Soft materials such as nylon hammer can be used to gently tap it. Only when the punch is properly positioned can the bolts be tightened.
2. Installation and debugging of die stamping.
The installation and calibration die must be very careful. Because the punch is particularly large and medium sized punch, it is not only costly, but also the weight of the small movement difficulty, the safety of the person should always be in the first place. The punch of the infinite bit device should add a pad of wood between the upper and lower modes. After the punch table is cleaned, the mold of the mold will be placed in a suitable position. Selected according to the requirements of process documentation and die design of press stroke, in the mold to the front to bottom dead center and greater than the location of the mould height 10 ~ 15 mm, adjust the slider connecting rod, the moving mould, ensure mold handle on die handle hole and achieve suitable loading height. The blanking die shall be fixed (not tightened) and then fixed (tightened).
T-type bolts should be tightened with a suitable torque wrench (bottom die) to ensure that the same bolt has a consistent and ideal pre-clamping force.
Can effectively prevent the occurrence of the manual screw thread caused by physical, gender, feel is error is too big or too small, the same thread pretightening pre-tightening force, leading to lower die stamping process change wrong move, clearance, chew strip edge failure, etc.
The mould is fully lubricated and ready for normal production before the test die, and the stamping dies 3 ~ 5 times to confirm the normal operation of the mould and then try again. Adjust and control punch into the depth of the concave die, examine and verify die guide, feeding, shirk, side pressure and pressure etc and the device performance and operating flexibility, and proper adjustment, to the best technology condition. The small and medium sized punch were tested for 3, 5 and 10 pieces respectively, and the test was made after the test was finished, and then 10, 15 and 30 pieces were tested again. Cross line detection
The punching and burr test, all dimensions and shape position accuracy are in accordance with the requirements of the drawing to be delivered to production.
3. Stamping burr
The clearance of the mold is too large or uneven.
The material and heat treatment of the die are not good, and the taper or cutting edge of the die is not sharp. The material should be reasonably selected and used in the mold work, and the heat treatment method is reasonable.
To wear, grind, punch or insert.
The punch and punch are deep into the concave mold, and the punch is adjusted to the depth of the die.
No precision or improper operation of the guide structure, the guide sleeve of the guide post and the guide precision of the punching machine, and the standard punch operation.
4. Jump waste
Die clearance is bigger, punch is shorter, the influence of the material (hard, brittle), stamping speed is too high, oil viscosity or oil droplets too attached to the role, pressing and vibration producing material spread crumbs, vacuum adsorption and die core is not sufficiently degaussing etc all can cause scraps to the mold surface.
The sharpness of the cutting edge. The larger the corner of the blade, the more likely it is to cause the scrap to rebound, and the stainless steel with thin material can be used as the oblique cutting edge.
For the waste of the comparison rule, it can increase the complexity of the waste material or add polyurethane top bar on the punch to prevent the jumping scrap, and increase the scratches on the edge of the cavity.
Whether the clearance of the mold is reasonable. Unreasonable die clearance, easy to cause waste rebound, reduce the clearance of small diameter by 10%, diameter greater than 50.00 mm, gap amplification.
To increase the depth of penetration. When stamping die, the requirement of the input modulus is certain, and the input volume is small, which is easy to cause the waste rebound.
The surface of the processed material is greasy.
Adjust the stamping speed and oil concentration.
It adopts vacuum adsorption.
It is used for demagnetization of punch, inserts and materials.
5. Pressure and scratch.
In the case of oil pollution and waste, it is necessary to clean the oil and install automatic air gun to remove the debris.
The surface of the mould is not smooth, and the surface finish should be improved.
The surface hardness of the parts is not enough, the surface needs to be chromed, carburized and boronizing.
The strain of material and material is unstable, reducing lubrication, increasing compressive stress and adjusting spring force.
The mold of the jumping scrap is made by the two parts.
When the product is scraped to the mold position or other place to cause the scratch, it is necessary to modify or reduce the positioning of the mould.
6. Surface abrasion after bending the workpiece.
The surface of the raw material is not smooth, clean, the material of the school plain.
To form a piece of waste material and remove debris from the block.
The molding block is not smooth, and the shaping block is electroplated and polished to improve the smoothness of the concave mould.
The radius R of the bending radius is too small to increase the bending radius.
The bending clearance is too small, adjust the bending and bending of the upper and lower dies.
The shape of the concave mold is formed by adding roller.
7. Leakage punching
Punching, the condition of the leakage fault was found, generally have punch die after packing subsidence caused by such factors as the punch, punch to conduct first article confirmation after repairing mold, compared to the sample, check whether there are omissions phenomenon, on the sink of the punch, should improve the hardness of die plate.
8. The stripping is abnormal.
(1), stripper and punch with tight, stripper tilt, such as screw height not unified device is undeserved, or other materials should be finishing materials, stripping screw adopts the form of the combination of casing and inner hexagon screws.
The gap between the mold and the die is small, and the punching head needs a lot of ejection force when the material is dissected, which causes the punch to be held by the material, which needs to increase the clearance.
There is an inverted cone in the concave mould and a concave mould.
The hole of the blanking and the blanking hole of the concave mould and the lower mold base are not correct.
To inspect the state of the processed materials. The material is dirty and adhered to the mold, so that the punch is bitten by the material and cannot be processed. The warped deformation material will be clamped on the punch after the punching, and it will be found that the warped deformation material needs to be smoothed and then processed.
The cutting edge of the punch, punch and lower die should be cut in time. Sharp edge of the mould can work out a beautiful cut surface, the blade is blunt, requires additional pressure, and rough workpiece cross section, produce very big resistance, grabbed the punch was stuff.
It is suitable to use oblique cutting edge.
To minimize wear and tear, improve lubrication condition, lubrication plate and punch.
If the spring or rubber spring is insufficient or fatigue loss, replace the spring in time.
The gap between the guide and the guide sleeve is too large, and the guide sleeve is repaired or replaced.
The error accumulation and parallelism are accumulated and reassembled.
The hole on the thrust block is not vertical, so that the small bump is offset, and the push block is repaired or replaced.
It is not perpendicular to the mounting of the mold or the guide column, and reassembly to ensure the verticality.
9. The bending edge is not flat and the size is unstable.
To increase the pressure line or prebending process.
The material pressure is not enough to increase the pressure.
The Angle of the convex and concave die is uneven or the bending force is not uniform, and the clearance of the convex and concave die is adjusted to make it uniform and polished.
The height of the height shall not be less than the minimum limit.
10. The bending surface is thinner.
The rounded corners of the concave die are too small to increase the radius of the concave.
The gap between the convex and concave dies is too small.
11. The bottom of the concave part is uneven.
The material itself is not flat and needs leveling material.
The roof and material contact area is small or the top material force is not enough. It needs to adjust the top feeding device to increase the top material force.
The top feeding device or calibration should be added.
B: yes. Plastic surgery.
12. Stainless steel flanging deformation.
Apply a high quality lubricant to the material before turning over the edge, which will make the material better separated from the mold and move smoothly down the surface of the mold during forming. This gives the material a better chance to distribute the stress generated by bending and stretching to prevent the deformation and the fraying of the bottom of the flange hole in the form of the forming flange.
13. Material distortion
A large number of holes are cut into the material, resulting in poor flatness of the material, which may be caused by the accumulation of ramming stress. When punching a hole, the material around the hole is pulled down to increase the tensile stress on the surface of the plate, and the lower surface pressure increases under the plate. For small holes, the results are not obvious, but as the number of punched holes increases, the tensile stress and compressive stress also increase exponentially until the material is deformed.
One way to eliminate this distortion is to cut each hole and then return to the remaining hole. Although the same stress is produced on the plate, the tensile stress/compressive stress accumulates in the same direction as a continuous one. This also allows the first holes to share the deforming effect of the second batch of holes.
14. Severe wear of mold.
Replace the worn mould guide component and punch in time.
Check whether the clearance of the die is not reasonable (small), and increase the clearance.
To minimize wear and tear, improve lubrication conditions, lubricate sheet and punch. The amount of oil and the amount of oil injected depends on the conditions of the processed materials. Cold rolled steel plate, corrosion resistant plate and other stainless steel materials, to the mold oil injection, oil injection point for the guide sleeve, oil injection port, lower die, etc. Oil is used in light oil. Have rust scale materials, processing the rust powder inhalation between the punch and guide bush, dirt, make the punch can not slide freely within the guide bush, in this case, if the oil, make rust scale is more likely to touch on, so when this material, on the contrary to wipe off the oil, decomposition time per month, with gasoline (diesel) oil remove the punch and die under the dirt, again to clean before assembly. This ensures good lubrication performance.
The method is not suitable, which causes the annealing of the mould and aggravates the abrasion. The grinding wheel should be used in the soft abrasive grinding wheel, with the small amount of the knife, the sufficient amount of coolant and regular cleaning of the grinding wheel.
15. Prevent stamping noise.
Punch is the most critical equipment in the processing industry. Punch at work would produce stamping mechanical transmission noise, noise and air dynamic noise, the noise is high up to 125 db (A) significantly more than the standard provisions of the state of 85 db (A) and its noise index under the requirements, and thus to the operator and the surrounding environment (e.g., office, residential areas, meeting rooms, etc.) cause extremely serious harm and pollution. Effective management of the noise has become an urgent problem. In particular, the implementation of the first "noise law" in China, the scale of environmental protection industrialization is increasing, and the urgency of this noise control is accelerated.
Starting from the noise source and mold structure of the punch, the following points should be paid attention to:
It is important to maintain and clean the mould and keep the edge sharp.
(2) the blade shape, quantity, material, mould and tangent length and mold parts and components interface is not too big, the punch ladder do oblique edge blanking, make the mold cutting depth is different in different locations, the true cut off the entire process, rather than synchronous crowded broken.
(3), mold parts must be installed perpendicular to the surface, and the blade fit clearance to reasonable, intensive unloading difficulty can increase the die clearance, increasing the discharge power, by adopting the method of soft unloading on the surface of the plate.
The coordination precision between the work templates and the working templates, and the processing of some exhaust grooves.
To make small pieces of small pieces, the stripper plate and the lower plate are changed into inserts to reduce the area of attack.
The springboard is replaced with a t-shaped top bar, and the spring is mounted on the upper mold base, which is equipped with the top and the top bar. In the open mode, there is a certain amount of free movement of the stripper.
Good lubrication, no interference and smooth operation.
The surface of the upper and lower modules is cushioned with a shock absorber.
After the adjustment of the mold, the sound insulation cover or the sound insulation of the sponge board will be added to the punch.
It can improve the accuracy of the punch and reduce the structural noise. In the work platform, the buffer damping and noise reduction oil cylinder is installed. The gear is equipped with the helical tooth to strengthen the lubrication and the gear cover, and the pneumatic system is equipped with muffler.
|
Down：How to improve the machining precision and surface quality of mold parts?
Up：How do injection molds prevent streak defects? |
| 【Back】 |
|
|
