1. It should be noted before using punch
①, with a clean cloth to clean punch.
②, to see if the surface scratch, dent. If so, then the oil stone removed.
③, timely oil rust.
④, careful not to have any inclination to install punch, soft materials and tools available like nylon hammer to gently knock it being only after the punch to tighten the bolts correctly positioned.
2. Installation and commissioning die
Installation and adjustment die must be particularly careful. Because die especially medium-sized die, not only too costly, and difficult to move heavy weight micro, personal safety should always come first. Die unlimited digital device should be added between the upper and lower dies of a mat board. In the press table to clean up after the state of the clamping die to be tested is placed countertops place. According to process requirements of the selected files and die design of the ram stroke, raised in the mold onto the next station before the dead and more than 10 ~ 15mm mold closed position height adjustment slider rod, moving die, make sure the handle of the mold associate handle hole and reach the appropriate die height. General blanking die first fixed lower mold (not tighten) and then fixed on the die (tighten), plate T-bolts are advised to use proper torque wrench to tighten (lower die), ensure that the same bolt with a consistent and desirable pre-clamping force. Can effectively prevent hand-tighten the threaded arise due to physical strength, sex, feel error caused by preload is too big or too small, ranging from the same threaded preload, causing the upper and lower die stamping process wrong move, the gap change, eating peel edge mouth, such as failure.
Tryout of dies before fully lubricated and ready to normal production of materials used in air travel startup die 3-5 times to confirm try punching die after normal operation. Adjust and control the depth of the punch into the die, the die guide to check and verify, feeding, shirk, performance and operational flexibility and lateral pressure biasing means and devices, and then be appropriately adjusted so as to achieve the best technical condition. 3,5,10 die tryout for large and small pieces were discontinued beginning of the seizure, try punching 10,15,30 pieces after passing the retest. After scribing detection, red and burr inspection section, all dimensions are in line with the shape and position accuracy requirements of the drawings in order to deliver production.
3. stamping burrs
①, the die gap is too large or uneven, re-adjust the die gap.
Improper ②, mold material and heat treatment, resulting in the die inverted cone or edge is not sharp, should be a reasonable selection, carbide die working part of the material, heat treatment and reasonable manner.
③, stamping wear, grinding punch or inserts.
④, punch into the die too, adjusting the depth of the punch into the die.
⑤, the guide structure is not sophisticated or improper operation, maintenance mold inside the guide pins and bushings and precision punch guide and standardize punch operation.
4. Jump waste
Die gap larger punch shorter, material impacts (hard, brittle), punching speed is too high, attached to the role of stamping oil droplets too sticky or too fast caused the chips punching vibration divergence, vacuum suction and mold core degaussing may be caused by not sufficiently brought to the mold surface litter.
①, sharpness of the cutting edge. Rounded edge, the more likely to cause waste to rebound, for relatively thin stainless steel and other materials can be used oblique edge.
②, comparison rules for waste, can increase the complexity of the waste or the punch ram plus polyurethane to prevent jumping waste, increase in the die edge side scratches.
③, gap mold is reasonable. Unreasonable die clearance, could easily lead to waste rebound gap for small-diameter hole 10% reduction in diameter greater than 50.00 mm, the gap amplification.
④, increasing the depth into the mold. Each station die stamping, the modulus requirement is certain, a small amount into the mold, could easily lead to waste rebound.
⑤, the surface of the workpiece is whether there is oil.
⑥, adjust the speed stamping, stamping oil concentration.
⑦, using vacuum suction.
⑧, punches, inserts, material handling demagnetization.
5. bruised, scratched
①, strip or mold with oil, debris, causing bruised, you need to wipe the oil and install automatic air gun to clear litter.
②, the mold surface is not smooth, should improve the mold surface finish.
③, parts of the surface hardness is not enough, the surface to be chrome, carburizing, boron and other treatment.
④, material strain and instability, reducing lubrication, increased stress, adjust the spring force.
⑤, for jumping waste mold □□□.
⑥, scrape the mold when the job is product positioning caused by scratching or elsewhere, modify or reduce mold positioning, education workers when the job gently.
6. Bend the outer surface of the workpiece scratch
①, raw surface is not smooth, clean, leveling materials.
②, molded into blocks have waste, remove scrap into blocks. .
③, forming block is not smooth, the molded block plating, polishing, improve punch finish.
④, punch bending radius R is too small, increasing the punch bending radius
⑤, bending mold gap is too small, adjust the upper and lower mold bend with the gap.
⑥, concave molding block the installation of roller forming.
7. Drain punching
Case leakage occurs punching, generally have not found a punch off after the repair mode leakage loaded punch, punch subsidence caused by other factors, after the repair mode to be the first confirmed cases, with a sample comparison, check if there are any omissions phenomenon, hedge head sinking, should improve the hardness of the die plate.
8. The stripper is not normal
①, stripper plate and with tight punch, stripper plate tilt, height is not uniform contour screws or other improper means stripper parts, materials and parts should be trimmed off, stripping the screw sleeve and socket head cap screws using a combination of form.
②, die gap is too small, need a lot of punch force at the time of the release from the material, causing the punch bitten materials, the need to increase the die gap.
③, die inverted cone, trimming die.
④, blanking die die holder drain hole and did not leak orifice orifice on the positive, trimming.
⑤, check the status of the work material. Dirt adhered to the mold material, so that is gripped by the punch and the material can not be processed. Warpage material after punching, will clamp the punch and found warpage material, to be leveled before processing.
⑥, the punch, the die cutting edge passivation to timely sharpening. Sharp edge of the mold can be processed a beautiful cut surface, the cutting edge is blunt, you need extra punch pressure, but the workpiece section rough, with great resistance, causing the punch was bitten materials.
⑦, appropriate use of oblique edge punch.
⑧, minimize wear and improve lubrication, lubrication plates and punch.
⑨, springs or rubber elastic enough or fatigue loss, timely replacement springs.
⑩, guide posts and bushings gap is too large, repair or replace the guide pins and bushings.
◎, parallelism error accumulation, re-grinding assembly.
◎, hole pusher on the block is not vertical, so that small punch deviation, repair or replace the pusher block.
◎, punch or vertical guide column is not installed, re-assembly, ensure verticality.
9. bending edge is not flat, dimensionally unstable
①. Increase the pressure line or pre-bending process
②. Binder material is not enough to increase the binder force
③. Punch fillet worn or bent asymmetric discontinuity, adjust the punch and die clearance to make it uniform, polishing punch fillet
④ height dimension not less than the minimum size limit
10. The curved surface of the extruded material thinning
①. Die radius is too small, increase the radius of die
②. Punch and die gap is too small, the correction punch clearance
11. The female member uneven bottom
①. Material itself is not flat, to be leveling material
②. Roof and material contact area is small or ejector force is not enough, you need to adjust the top feeding device, increasing the ejector force
③. Unroofed feeding device, should increase the ejector device or corrected within the die
④. Plus shaping process
12. Stainless steel flange deformation
Administered prior to the fabrication of high quality molded flange lubricant into the material, which will enable a better separation of the material out from the mold, the lower surface of the movable mold during molding smoothly. So give the material a better chance to distribution of stress caused by bending and is stretched to prevent wear and tear occurs in forming the edge of the hole flanging deformation and burring holes at the bottom.
13. Materials twist
Punching a lot of holes in the material, resulting in poor material flatness, punching stress causes may be cumulative. When punching a hole, the hole surrounding material is stretched downward, so that the sheet surface tensile stress increases, lower punch movement also causes the surface compressive stress under the plate increases. For punching holes in a small amount, the result is not obvious, but with the increase in the number of punched holes, tensile stress and compressive stress is increased exponentially until the material is deformed to make.
One way to eliminate this distortion is: every hole punching, punched and then return the remaining holes. Although this produces the same stress on the plate, but in the same direction due to the collapse of a continuously produced immediately punched by one tensile stress / compressive stress build-up. So also made the first hole to share the deformation effect of the second batch of the hole.
14. Die severe wear
①, timely replacement of worn die and the punch guide assembly.
Whether ②, check die gap unreasonable (small), increasing the die gap.
③, minimize wear and improve lubrication, lubrication plates and punch. Depending on the number of oil and grease materials processing conditions. Cold-rolled steel, corrosion resistant steel and other rust-free materials, to give Mould oiling, oiling point of the guide sleeve, the filler, the lower mold and so on. Oil with a light oil.
There rust materials, processing rust powder breathe between the punch and the guide sleeve, produce dirt, making the punch can not slide freely in the guide sleeve, in this case, if oil will make it easier to stick rust on, so when the punch of this material, the opposite should clean the oil, exploded a month back, with steam (diesel) to the punch, the die remove dirt, then wipe clean before reassembly. This ensures that the mold has good lubricating properties.
④, sharpening improper methods, resulting in mold annealing, increased wear, you should use a soft abrasive grinding wheel, using a small knife to eat an amount, sufficient amount of coolant and frequent cleaning wheel.
15. prevent stamping noise
Punch is the most critical of the necessary equipment sheet metal processing industry. 85dB (A) punch at work will produce mechanical transmission noise, stamping noise and aerodynamic noise, the noise maximum value of up to 125dB (A) greatly exceeded the national standards for noise and below target, thus operating workers and the surrounding environment (such as offices, residential areas, meeting rooms, etc.) caused very serious damage and pollution. Effectively govern the noise has become a pressing problem. Especially the increasing implementation of the scale of China’s environmental protection industry’s first “noise law”, but accelerated the urgency of this noise control.
Starting punch noise source and mold structure, to reduce noise was to note the following:
①, focusing on mold maintenance, cleaning, maintaining sharp edge.
②, the shape of the mold edge, quantity, material and punching line length, die cutting edge contact surface with parts not too much punch to make oblique edge blanking ladder, the die cut at different depths in different positions, the whole process to achieve true cutting, rather than synchronized to squeeze off.
③, die cutting edge must be perpendicular to the mounting surface, and punch and die cutting edge with the gap to be reasonable, increase the difficulty when unloading the die gap, increasing discharge power, soft surface discharge boards and other methods.
④, with precision between the working template, processing some of the exhaust ducts.
⑤, the stopper plate changed into small pieces to fight, stripper plate, under the template to insert the formula, reducing the attack area.
⑥, stripper plate spring-loaded plunger source to the T-spring mounted on the mold base, equipped with high-sleeve and mandrel to ensure that the stripper plate is still a certain amount of freedom of movement under the open state.
⑦, maintain good lubrication, mold without interference, smooth.
⑧, the upper and lower surfaces of the mold seat cushion made of aluminum momentum buffer.
⑨, Die After commissioning, the punch install soundproof acoustic enclosures or sponge board processing.
⑩, improve punch accuracy and reduce structural noise. Installation work bench cushion cylinder vibration and noise reduction, helical gear used to enhance the lubrication and installation of the gear cover, installation of pneumatic system muffler.
Workaround mold maintenance repair work in 15 Common Problems
1. It should be noted before using punch