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Hardware mold maintenance and repair 15 common problems analysis
- 2019-03-25-

1. Metal casing punch should pay attention to the application before application

1 Clean the punch with a clean cloth.

2 Check if there are scratches or dents on the outside. If there is, remove it with oil stone.

3 Real-time oil rust prevention.

4 When the device is punched, be careful not to have any skew. Use a soft data object such as a nylon hammer to make it light and small. Just tighten the bolt after the punch is accurately positioned.
2. Die device and debugging

The device and the adjustment die must be carefully handled. Because the die is especially large and medium-sized die, not only is the price high, but the weight is too large to move hard, the safety of the person should always be in the first place. The die of the infinite position device should be provided with a pad between the high and low modes. After the clearing and cleaning of the punching table, the mold to be tested in the mold clamping state is placed on the countertop for a suitable position. According to the process file and the die design request, the selected press slider stroke is adjusted to the bottom dead center in front of the mold and is greater than the mold closing height of 10 to 15 mm. The slider connecting rod is adjusted, and the mold is moved to ensure the mold holder pair. The shank hole is reached and reaches the appropriate mold height. As usual, the punching die first fixes the lower die (not tightened) and then fixes the upper die (tightening). The T-bolt of the pressure plate should be applied with a torque wrench (lower die) to ensure that the same screw has the same and ambiguous pre-clamp Tight force. It can be used to avoid the excessive tightening force caused by the force, gender and hand deviation caused by the manual tightening of the rib, and the pre-tightening force of the rib is different, which causes the high and low mode shift, the gap change and the peeling edge in the stamping process. Oral problems occur.

Before the test, the mold is stopped and smoothed, and the material for the abnormal use is prepared. After the die is started for 3 to 5 times in the idle stroke, the mold is operated abnormally and then tested. Adjust and control the punch into the die depth, reflect and verify the function and operational flexibility of the mechanism and device such as die guiding, feeding, derogation, side pressure and repression, and then stop proper conditioning to achieve the best skill. For the large, medium and small sized die separation test 3, 5, 10 pieces stop the initial inspection, and then test 10, 15, 30 pieces to stop the re-examination. After the scribing test, the punching surface and the burr inspection, the overall size and the shape and position accuracy are consistent with the drawing request, and the capability is delivered.

3. Stamping burr

1 The mold gap is too large or uneven, and the mold gap is newly adjusted.

2 The mold material and heat treatment are not proper, and the concave die or the cutting edge is not sharp. The material should be properly selected and the material of the mold department should be made of hard alloy. The heat treatment method is justified.

3 Stamping wear, grinding punches or inserts.

4 The punch enters the die too deeply, and the punch is adjusted to enter the die depth.

5 The guiding layout is not precise or the operation is poor. The guide bush guide bushing and the punching guide precision in the mold are repaired, and the punching operation is regulated.

4. Jumping waste

The mold gap is large, the punch is short, the influence of the material (hardness, brittleness), the stamping rate is too high, the stamping oil is too sticky or the oil droplets form too fast, the stamping vibration causes the material to diverge, the vacuum adsorption and the core If the degaussing is not sufficient, the waste can be brought to the die surface.

1 The sharpness of the cutting edge. The larger the rounded corner of the cutting edge, the easier it is to form a waste bounce, and the stainless steel can be used to deal with the oblique edge.

2 To deal with the equivalent of waste, increase the complexity of the waste or add a polyurethane ram on the punch to avoid jumping waste and grow scratches on the edge of the die.

3 Whether the gap of the mold can be justified. Improper mold clearance, easy to form waste rebound, to deal with small diameter hole clearance 10%, diameter greater than 50.00 mm, clearance amplification.

4 Increase the depth of the mold. When stamping each station mold, the request for the modulus is constant, and the modulus of the mold is small, which is easy to form a waste rebound.

5 Whether there is oil on the outside of the processed materials.

6 Adjustment stamping rate, stamping oil concentration.

7 Adopt vacuum adsorption.

8 Punch, insert, and data stop demagnetization.

5.Corrosion, scratching 1 The belt or mold has oil stains and waste, causing crushing. It is necessary to wipe the oil and install an automatic air gun to eliminate the waste.
2 The outside of the mold is not smooth, and the outer surface of the mold should be improved.

3 The hardness of the whole machine is not enough, and the outside should be treated with chrome plating, carburizing, boronizing, etc.

4 The data is strained and unstable, reducing smoothness, increasing compressive stress, and conditioning spring force.

5 Stop the mold for jumping waste □□□.

6 During the course of the course, the product is scraped to the location of the mold or other places to form a scratch, and the mold positioning needs to be modified or lowered to teach the homework staff to take care of the lesson.

6. The outer and outer scratches after the workpiece is bent

1 The original data is not smooth outside, clean and plain information.

2 Formed into the block with waste, eliminating the waste between the blocks. .

3 The forming block is not smooth, and the forming block is plated and polished to improve the smoothness of the convex and concave mold.

4 The bending radius R of the punch is too small to increase the tortuous radius of the punch

5 The mold tortuous gap is too small, adjust the high and low mold tortuous joint gap.

6 The die forming block is equipped with roller forming.

7. Leakage punching

In the case of leaking punching holes, the same is usually found when the punch is not broken, the missing punch is repaired after the mold is repaired, and the punch is depressed. After the mold is repaired, the first part is confirmed. Compare with the sample and reflect whether there is any omission. If the punch is sinking, the hardness of the upper plate should be improved.

8. Unloading is not abnormal

1 The stripping plate and the punching die are too tight together, the stripping plate is skewed, the height of the screw is not uniform, or the other stripping device is defective. The stripping part should be trimmed, and the stripping screw adopts the combination of the sleeve and the hexagon socket screw. form.

2 The mold gap is too small, and the punch must have a large stripping force when it is separated from the data, so that the punch is bitten by the data, and the gap of the lower mold needs to be increased.

3 The die has an inverted cone to trim the die.

4 The die blank hole and the lower die hole leak hole are not aligned, and the leak hole is trimmed.

5 Reflect on the status of processing data. The data is dirty and attached to the mold, so that the punch is bitten by the data and cannot be processed. After the punching, the data of the warping deformation will clamp the punch, and the data of the warping deformation should be flattened and then processed.

6 The cutting edge passivation of the punch and the lower die should be sharpened in real time. The sharp-edged die can process a beautiful plugging section, and the cutting edge is blunt, so additional punching force is required, and the workpiece has a rough section, which generates great resistance, and the punch is bitten by the data.

7 Properly adopt the oblique edge punch.

8 Even if the wear is reduced, the smoothing premise, smooth sheet and punch are improved.

9 Spring or rubber elastic or fatigue loss, change the spring in real time.

10 The distance between the guide post and the guide sleeve is too large, and the guide post guide sleeve is reworked or replaced.

◎ Accumulation of parallelism deviation, from the new grinding device.

◎ The hole on the pusher block is not vertical, so that the small punch is biased, and the pusher block is reworked or replaced.

◎ The punch or guide column device is not vertical, and the verticality is covered by the new device.

9. The metal casing is not bent straight and the size is unstable.

1 Growth line or pre-bending process

2 The data pressure is insufficient, and the pressing force is increased.

3 The concave and convex molds have asymmetrical wear or uneven bending force, and the convex and concave mold gaps are evenly distributed, and the convex and concave molds are rounded.

4 height size can not be less than the minimum limit size

10. Zigzag outer extrusion thinning

1 The die fillet is too small to increase the radius of the die corner

2 The clearance between the convex and concave molds is too small, and the gap between the convex and concave molds is corrected.

11. The bottom of the concave piece is unyielding

1 Information is unyielding, need to level the information

2 The top plate and the data of the snoring area are small or the top material is not enough, and the ejector device needs to be adjusted to increase the top material force.

3 There is no topping device in the die, and the topping device should be grown or revised.

4 plus shaping process

12. Stainless steel flange deformation

An excellent shaped smoothing agent is applied to the data prior to making the burring, which allows the data to be better separated from the mold and smoothly moved outside the mold during forming. As a result, there is a better opportunity to spread the stresses that are generated when bent and stretched, to avoid deformations on the edges of the formed flanged edges and wear at the bottom of the flanged holes.

13. Data distortion

Punching a large number of holes in the data, resulting in poor data stereology, the cause can be the accumulation of stamping stress. When punching a hole, the data around the hole is stretched downward, so that the tensile stress on the outer surface of the plate is increased, and the undershooting action also causes the compressive stress on the outer surface of the plate to increase. Dealing with a large number of holes, the results are not obvious, but with the number of punching targets increasing, the tensile stress and compressive stress are also multiplied until the data is deformed.

One way to dispel this type of deformation is to punch every other hole and then go to the remaining hole. This produces the same stress on the sheet, but disintegrates the tensile stress/compressive stress accumulation due to the continuous punching of the same direction. This also allows the first batch of holes to be responsible for the deformation effects of the second batch of holes.

14. Metal casing mold major wear and tear

1 Change the mold guide assembly and punch that was worn out in real time.

2 Investigate whether the mold gap can be improper (small) and increase the gap between the lower molds.

3 Even if the wear is reduced, the smoothing premise, smooth sheet and punch are improved. The amount of oil and the number of oil injections depend on the premise of the processing data. For the non-rust-proof materials such as cold-rolled steel sheets and corrosion-resistant steel sheets, oil is to be injected into the molds. The oil-injection points are guide sleeves, oil filling ports, and lower molds. Light oil for oil.

There is rust scale information. During processing, the rust powder will be sucked between the punch and the guide bush to produce dirt, so that the punch can not slide freely in the guide sleeve. In this case, if the oil is used, the rust will become more easily stained. When rushing such information, the same oil should be cleaned and cleaned once a month. The dirt of the punch and the lower mold is removed with steam (wood) oil, and then cleaned before being assembled. This allows the tube die to have superior smoothness.

4 The sharpening method is not good, forming the annealing of the mold and aggravating the wear. When applying the soft abrasive grinding wheel, adopt a small amount of knife, sufficient coolant and often clear the grinding wheel.

15. Avoid stamping music

Punch is the most essential equipment for the sheet processing industry. The punching machine will produce mechanical transmission noise, stamping noise and ambient dynamic noise, which can reach a maximum of 125dB (A) greatly exceeding the 85dB (A) specified by the national standard and its noise target request as follows, thus the operator And the surrounding environment (such as offices, residential areas, conference rooms, etc.) form extremely serious damage and purification. Usefully managing this noise has become an urgent task. It is the implementation of the first "Noise Law" in China, and the scope of environmental protection industrialization is increasing day by day, which accelerates the urgency of this noise management.

From the punch noise source and mold layout, you should pay attention to the following points:

1 Pay attention to mold maintenance, clean, and insist on sharp edges.

2 The shape, number, data and punching line length of the die cutting edge, the die cutting edge and the whole machine do not have too much snagging surface, the punching machine makes the oblique blade door punching, so that the die cuts into the depth difference in the divergent position, and all the processes are completed. Blocking, not simultaneous squeezing.

3 The die edge must be perpendicular to the device surface, and the common clearance of the convex and concave die edges should be justified. When the unloading is difficult, the die clearance can be increased, the unloading force can be increased, and the soft unloading plate can be adopted.

4 The common precision between the templates of each thing, processing some exhaust slots.

5 The baffle plate is changed into a small piece, and the stripping plate and the lower plate are changed into inserts to reduce the area of the whip.

6 The origin of the stripping plate is changed into a T-shaped ejector, the spring is installed in the upper mold base, the contour set is matched with the ejector rod, and there is still a certain amount of free movement in the unloading plate under the mold opening condition.

7 Adhere to smooth and superior, mold without intervention, smooth.

8 The aluminum plate on the outer side of the high and low mold bases is used for impulse buffering.

9 After the mold is adjusted, install sound insulation cover or sponge board on the punching machine for soundproofing.

10 Improve punching accuracy and low layout noise. On the table, the device is equipped with a buffer damping and noise reduction cylinder. The gear adopts a helical tooth to enhance the smoothness and the addition of a gear cover, and a muffler is added to the pneumatic system.