and analysis of counter measures- Changdong-professional stamping die maker in China
1.Scrap jumping
1)The length of the punch is not enough. Cut the punch into the die with a punch and add 1mm to replace the punch.
2)The die gap is too large, the cutting edge reduces the gap or the gap is reduced by the coating machine.
3)The punch or template is not demagnetized, and the punch or template is demagnetized with a demagnetizer.
2.Waste caving
1)The blanking hole is small or the blanking hole is biased to increase the blanking hole, so that the blanking is smooth.
2)The blanking hole has a chamfering angle, and the blanking hole is removed to remove the chamfering.
3)The blade edge is not tapered, the wire taper or the reverse face hole reduces the straight wall length.
4)The straight wall of the knife edge is too long, and the back side is drilled, which shortens the straight wall position of the knife edge.
5)The edge of the blade collapses, causing the cloak to be large, and the material is re-ground.
3.Bad Burrs
The edge of the blade collapses, causing the edging to re-grind the edge.
The gap between the punch and the die is too large, the line is cut into the block, and the gap is re-fitted.
The die has a poor finish and the straight edge of the polished edge
The clearance between the punch and the die is too small, and the mode is saved again.
The top material force is too large, and the thief is reversed to change the spring to reduce the top material force.
4.Neat Trimming
Positioning offset adjustment positioning.
One-side stamping diesing, pulling material to increase the pressing force, adjust positioning.
Wrong design, resulting in uneven knives.
Feeding is not allowed to adjust the feeder.
The feed step calculation is incorrectly recalculated, and the tool position is re-set.
5.Easily-Broken Punch
The closing height is too low, and the punch is cut into the knife edge to adjust the closing height too long.
Improper positioning of the material causes the punching punch to cut unilaterally, and the positioning or feeding device is broken due to uneven force.
The lower stamping dies waste blocks the knife edge, causing the punch to break the large hole and make the blanking smooth.
The fixed part (plywood) of the punch is trimmed with the guide part or re-cut into the block to make the punch up and down smoothly (plate).
The plate is poorly oriented, causing the punch to be unilaterally forced to refit the plate gap.
The punch edge is too short, and the punch is interfered with the punch to change the punch, and the length of the blade is increased.
The punch is not fixed properly, and the punch is lifted up and down to fix the punch so that it cannot move up and down.
The punch edge is not sharp and the edge is re-grinded.
The surface of the punch is strained, and the force is unevenly changed when the material is removed.
The punch is too thin, too long, not strong enough to change the punch type.
The punch hardness is too high, the punch material is not correct for the punch material, and the heat treatment hardness is adjusted.
6.Iron filings
Recalculating the position of the rib or the position of the bend.
The bending gap is too small, the iron scraps are re-adjusted, or the forming block is ground, or the grinding punch is formed.
Bending punch is too sharp to repair the R angle.
The blade material is too small to reconnect the knife edge.
The rib is too narrow to re-grind the rib.
7.Bad sprouting
The center of the bud bottom hole and the center of the bud punch do not overlap to determine the correct center position, or move the position of the bud punch, or move to the bud-edge height-side low or even rupture pre-punching position, or adjust the positioning.
The gap of the die is not uniform, resulting in low bud-edge height-side trimming and low rupture.
The bottom hole of the bud is not in accordance with the requirements, resulting in the height of the bud and the recalculation of the hole diameter of the bottom hole, the pre-punching increases or decreases the diameter deviation, and even ruptures.
8.Poor stamping diesing
The forming die is too sharp, causing the material to be cracked to form a convex stamping dies to repair the R angle, and the R angle is appropriately corrected at the edge of the blade.
The length of the forming punch is not enough, resulting in failure to form the correct length of the punch to adjust the actual length of the punch to achieve the type requirement.
The forming punch is too long, the material at the forming part is deformed by pressure, and the correct length of the punch is determined, and the actual length of the punch is adjusted to meet the requirement to break the punch.
Insufficient material in the forming section causes the crack to calculate the unfolding material, or repair the R angle, or reduce the forming height.
Poor positioning, resulting in poor stamping diesing positioning or feeding device.
The forming gap is too small to cause cracking or deformation matching clearance.
9.Bending size
If the stamping dies is not adjusted, the angle error will cause the size to be adjusted. The closing height is poor or the angle difference is poor.
Insufficient elasticity, resulting in poor angle, resulting in dimensional deviation.
If the material does not meet the requirements, the angle is poor, and the material is changed or the gap is re-adjusted.
Material thickness deviation causes poor angle, resulting in size deviation, material thickness, material change or re-adjustment gap difference.
Improper positioning leads to dimensional deviation adjustment positioning to make the size OK.The design or processing error causes the repair and grinding between the bending blocks, eliminating the gap between the blocks, resulting in a small bending size.
The stamping diesing has no R angle, and the bending height is small under the angle and other normal conditions.
Bending size on both sides is too large.
Single-sided bending and pulling material cause dimensional instability, increase spring force, adjust positioning.
Unreasonable clearance, causing poor angle and dimensional deviation repair clearance.
The height of the folding knife is not enough. The folding punch is too short to increase the folding knife height, so that the bending punch can fit into the folding knife position as much as possible.
When the bending speed is too fast, the deformation of the bending root is adjusted to adjust the speed ratio, and the reasonable speed is selected.
The structure is unreasonable, the folding knife is not set in the fixed template, the groove is re-milled, and the folding knife is set into the template stamping, causing the gap to become larger.
Forming punch heat treatment hardness is not enough, causing pressure line collapse or re-forming type of public pressure line to level
10.No discharge
Improper positioning or improper feeding adjustment positioning or feeding device.
Avoiding enough to avoid wearing.Internal guide column strain, resulting in poor plate movement, replacing the inner guide column.Punch or scratched surface, replace the punch.
The top pin is unreasonable and the top pin position is re-arranged.
The top material is not enough, or the stripping force is not enough. Replace the top spring or the spring.
The punch and the splint are not smoothly matched with the plate and the splint to make the punch fit smoothly.
The forming slider is matched with the smoothing slider and the guiding groove to make it fit smoothly.
The heat treatment of the plate is not suitable.
The punch is too long or the length of the top pin is not enough to increase the length of the top pin or the replacement of the length of the punch.
Replace broken punch.
The template is not clouded, and the workpiece is brought up to demagnetize the template.
11.Feeding is not smooth
The stamping dies is not in the positive position, causing the strip to not be on the same line as the feeder and the stamping dies re-stamping dies or the adjustment feeder.
Adjust the leveling machine or replace the material with unevenness.
No unloading, no feeding, no discharge, no solution.
Positioning is too tight to adjust positioning.
The guiding pin is too tight or the straight wall is too long to adjust the guiding pin.
The punch is not fixed or is too long, and the tape is interfered with and the length of the punch is re-fixed.
The top pin is too short, and the tape interferes with the forming block to adjust the length of the top pin to avoid interference.
Float block position misalignment adjusts the position of the lifting block.
12.Poor riveting
The stamping dies closing height is improperly riveted and the position is not adjusted.
The workpiece is not in place, positioning deviation adjustment positioning.
Before the riveting, the workpiece is poorly confirmed to confirm the bud hole. Refer to the blasting hole for countermeasures to check whether the staking hole is chamfered. If there is no chamfer, increase the chamfer.
Riveting punch length is not enough to change the length of the punch.
Riveting punch does not meet the requirements to confirm and use the riveting punch that meets the requirements.
13.Missing Installation
Inadvertently set up a fashion wrong punch.
The punch has no direction mark and has a directional punch.
14.Install Wrong screw
Don't know the thickness of the template. The thickness of the template is too long or too short.
Not careful enough, lack of experience, use the appropriate screws.
15.Disassembly Stamping Dies
The pin hole is not cleaned and the pin hole is cleaned. The pin is cleaned. When the stamping dies is removed, it is easy to damage the stamping dies when the pin is removed. The screw should be used first, then the positioning pin hole.
Do not damage the pin hole when loading and unloading the stamping dies.
16.Locating pin
When the hole wall is pulled and the scratch is too tight, carefully check whether the pin hole is pulled. Otherwise, the pin hole should not be reamed.
Pin hole offset or no escape hole below additional positioning pin escape hole.
17.Too Long Spring
Did not pay attention to the depth of the spring hole, the depth of the spring hole, calculate the compression of the spring, re-selection can not be pressed down.
Not careful enough, the lack of experience is suitable for the bottom of the spring.
Analysis of common problems in progressive stamping die (2)
In the stamping production of progressive stamping die, it is necessary to carry out specific analysis for the phenomenon of poor stamping, adopt effective treatment measures, and fundamentally solve the problems that occur, so as to reduce production costs and achieve smooth production. The following are the reasons for the common bad stamping phenomenon in production and the treatment measures are as follows, for the stamping dies maintenance personnel to refer to.
1. Stamping Parts With Burrs
(1) Reason: A, cutting edge wears; B, the effect is not obvious after the gap is too large to repair for cutting edge; C, the cutting edge collapse angle; D, the gap is unreasonably up and down offset or loose; E,up and down dislocation.
(2) Countermeasures: A, grinding the cutting edge; B, controlling the convex or concave die machining accuracy or modifying the design clearance; C, grinding the blade; D, adjusting the punching clearance to confirm the template hole wear or the processing accuracy of the stamping diesed part; E, replacement guide Piece or re-form.
2.Scrap smashing
Reason: A, the gap is too large; B, improper feeding; C, the stamping oil droplets are too fast, the oil is sticky; D, the stamping dies is not demagnetized; E, the punch is worn, and the scrap is pressed onto the punch; F, The punch is too short, the length of the inserted die is insufficient; G, the material is hard, and the punching shape is simple;H.Emergency measures
(2) Countermeasures: A. Control the accuracy of the convex and concave die machining or modify the design clearance; B.Trim the tape and clean the stamping dies in time when it is sent to the appropriate position; C.Control the amount of oil in the stamping oil, or change the oil to reduce the viscosity; D.After the training, the magnet must be demagnetized (more attention should be paid to the iron); E, the punching edge of the punch; F, adjust the length of the punch into the die; G,replace the material, modify the design. The punch is bladed into the end face to mount or trim the bevel or arc (note the direction). Reduce the bonding area between the end surface of the punch edge and the chip; H,reduce the sharpness of the edge of the die, reduce the grinding amount of the die edge, and increase the roughness (cover) of the surface of the straight edge of the die, Use a vacuum cleaner to absorb waste. Reduce the speed of the collision and slow down the chipping.
3. Scrap blockage
(1) Reason: A, the leakage hole is small; B, the leakage hole is too large, the material is tumbling; C, the knife edge is worn, the burr is large; D, the stamping oil droplet is too fast, the oil is sticky; E, the concave stamping dies is straight The surface of the blade is rough, the powder is sintered and adhered to the blade; F, the material is soft; G, emergency measures.
(2) Countermeasures: A, modify the leakage hole; B, modify the leakage hole; C, blade repair knife; D, control the amount of oil, replace the oil; E, surface treatment, polishing, pay attention to reduce the surface roughness Change the material, F, modify the blanking clearance; G, the edge of the convex die edge is trimmed or curved (note the direction), use a vacuum cleaner to add air to the blanking hole of the pad.
2.Cutting bias size variation
(1) Reason: A, the convex and concave die edge wear, resulting in burrs (larger shape, smaller inner hole); B, improper design size and clearance, poor machining accuracy; C, lower punch and die insert Equal offset, uneven gap; D, guide pin wear, insufficient pin diameter; E, guide wear; F, feeder feed distance, press material, loose adjustment improper; G, stamping dies closed stamping dies height adjustment is improper; The material of the stripping block is worn, the material without pressure (strong pressure) function (the material is pulled by the material to make the punching small); I,the strong pressure of the unloading insert is too deep, the punching is too large; J, the mechanical properties of the stamping material vary ( Strength elongation is unstable); K,when punching, the punching force pulls on the material, causing dimensional variation.
(2) Countermeasures: A, grinding the knife edge; B, modifying the design, controlling the machining accuracy; C, adjusting its positional accuracy, punching the gap; D, replacing the guiding pin; E, replacing the guide post, guide bush; F, re-adjusting Feeder; G, re-adjust the stamping dies closing height; H, grind or replace the stripping insert, increase the strong pressure function, adjust the press material; I, reduce the strong pressure depth; J, replace the material, control the feed quality; K, punch The end face of the blade is trimmed with a slope or an arc (note the direction) to improve the stress during the punching. When the license is applied, the loading part is placed on the unloading insert to provide a guiding function.
5.Material Stocked
Reasons: A, feeder feeding distance, pressing material, loose adjustment improperly; B, variation in delivery distance during production; C, feeder failure; D, material arc, width is out of tolerance, large margin; E, die stamping abnormal , the sickle bend is triggered; F, the guide material aperture is insufficient, the upper stamping dies pulls; G,the bending or tearing position is not smooth; the H, the material strip is not properly set, the strip is on the strip; The material is thin and fed into the middle warp; J, the stamping dies is not properly erected, and the deviation from the verticality of the feeder is large.
(2) Countermeasures: A, re-adjustment; B, re-adjustment; C, adjustment and maintenance; D, replacement of materials, control of feed quality; E, elimination of material belt boring; F, training and aligning positive hole convex, concave stamping dies ; G, adjust the strength of the stripping spring; H, modify the guide material, the belt on the anti-material belt; I, add the upper and lower press material between the feeder and the stamping dies, add the upper and lower squeeze material safety switch; J, re-erect the stamping dies..
6.Belt with a sickle
(1) Reason: A, stamping burrs (especially on the carrier); B, material burrs, stamping dies without trimming; C, improper punching depth (too deep or too shallow); D, stamping damage, swarf in the stamping dies Material; E, local pressure material is too deep or partial pressure to the part; F, stamping dies design.
(2) Countermeasures: A. Repair the cutting edge; B. Replace the material, add the trimming device to the stamping dies; C, re-adjust the depth of the punch; D, clean the stamping dies to solve the problem of chipping and crushing; E, check and adjust the The stripping and die inserts are of the correct height and the damage is repaired;
Adopt the adjustment of bending mechanism.
7. Punch Break
(1) Reasons: A, chipping, chip blocking, jamming, etc.; B, improper feeding, cutting half material; C, convex stamping dies strength is insufficient; D, size convex stamping diess are too close, material drawing during punching, Inducing small convex die breaks; E, convex and concave stamping diess are too sharp corners; F, blanking clearance is small; G, no stamping oil or used stamping oil is more volatile; H, punching gap is uneven, partial Displacement, convex and concave stamping dies interference; I, poor precision or wear of the insert insert, loss of precision guiding function; J, stamping dies orientation is not accurate, wear; K, convex, concave stamping dies material is improperly selected, improper hardness; I, guide Material (pin) wear; m, gasket is improperly installed.
(1) Countermeasures: A. Resolve problems such as chipping, chip blocking, and card stamping dies; B. Pay attention to feeding, trim the tape in time, and clean the stamping dies in time; C. Modify the design, increase the overall strength of the punch, and shorten the die. Straight blade size, pay attention to the edge of the convex blade to repair the slope or arc, the small part is cut later; D, the length of the small punch is shorter than the thickness of the large punch; E, modify the design; F, control the convex and concave stamping dies processing accuracy or modify the design gap, the small part of the punching gap is appropriately increased; G, adjust the amount of stamping oil drip or replace the oil; H, check the accuracy of each forming part, and apply adjustment or replacement to control the machining accuracy; , repair or replacement; J, replace the guide post, guide sleeve, pay attention to daily maintenance; K, replace the use of materials, use the appropriate hardness; I, replace the guide parts; m, correction, the number of gaskets can be less, and use steel pads The under-die gasket needs to be placed under the spacer.
8.Bending deformation size variation
(1) Reason: A, the leading pin is worn, the pin diameter is insufficient; B, the bending guide part is inferior in accuracy and wear; C, the bending convex and the concave die wear (pressure loss); D, the stamping dies yield is insufficient; E, material slip, bending convex, concave stamping dies without guiding function, no preloading during bending; F, stamping dies structure and design size is poor; G, punching edge, causing poor bending; H, bending There are many shims in the convex and concave stamping diess, which cause dimensional instability; I. Material thickness and size variation; J, material mechanical shape variability.
(1) Countermeasures: A, replace the guide pin; B, re-grind or replace; C, re-grind or replace; D, check, correction; E, modify the design, add guide and pre-press function; F, modify the design size , Decompose the bend, increase the bending and shaping, etc.; G, repair the material cutting edge; H, adjust, use the integral steel pad; I, replace the material, control the feed quality; J, replace the material, control the feed quality.
7. Stamping Parts Quantity
(3)Reason: A, punching edge; B, punching is crushed, there is chip in the stamping dies; C, convex, concave die (bending position) pressure loss or damage; D, turning when punching; E , related pressure parts wear, pressure loss; F, the relevant tearing position tearing size is inconsistent, the knife edge wear; G, the relevant easy to break position pre-cut depth is inconsistent, the convex and concave stamping dies has wear or chipping; H, the relevant convex part convex and concave The stamping dies has chipping or wear is more serious; I, stamping dies design defects.
(2) Countermeasures: A. Repair the cutting edge of the material level; B. Clean the stamping dies to solve the floating problem of the scrap; C, re-train or replace the new one; D, repair the cutting edge, adjust or add the strong pressure function; E, check, Perform maintenance or replacement; F, repair or replace, to ensure the same condition of tearing; G, check the condition of pre-cut convex and concave stamping dies, implement maintenance or replacement; H, check the condition of convex and concave stamping dies, implement maintenance or replacement; I. Design, add high and low adjustments or add plastic working stations.
10.Improper maintenance
(1) Reason: A. There is no foolproof function in the stamping dies. If the stamping dies is inadvertently, the reverse direction and misalignment (refer to different stations) are caused. B. The insert that has been offset by the gap is not restored as it is.
(2)
(2) Countermeasures: A. Modify the stamping dies, increase the anti-stay function; B. Make a mark on the stamping dies, and make necessary inspections and confirmations after the stamping dies is set, and make a written record for inquiries.
(3) In the stamping production, the daily maintenance work of the stamping dies is very important, that is, daily check to check whether the press and the stamping dies are in a normal state, such as the fuel supply guide portion of the fueling. The inspection before the machine on the stamping dies, the inspection of the blade, the confirmation of the locking of each part, etc., can avoid many sudden accidents. When you are repairing a stamping die, you must first think about it and do it carefully.
Analysis of common problems in automotive stamping die
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1.Flanging and shaping parts deformation
In the process of flanging and shaping, deformation of the part often occurs. In non-surface parts, it does not generally affect the quality of the part, but in the surface part, as long as there is a little deformation, it will bring a very good appearance. Large quality defects affect the quality of the entire vehicle.
Reason
1. Due to the deformation and flow of the sheet during the forming and flanging process,if the pressing material is not tight, deformation will occur;
2. In the case where the pressing force is large enough, if the pressing material is unevenly pressed and there is a gap in the part, the above situation may occur.
Solution
Increase the pressing force. If the spring is pressed, the spring can be used. For the upper air cushion, the air cushion is usually used.
If the pressure is increased, there is still some deformation in the local, you can use Red Dan to find out the specific problem, check whether there is a partial depression in the pressure surface, and then you can use the method of welding the pressure plate.
After the pressure plate is welded, the lower profile of the stamping dies is tested.
2.Cutting Edge Broken
The chipping of the stamping dies due to various reasons during use will have a certain impact on the quality of the part. It is one of the most common repairs in stamping dies repair. The steps to repair the blade are as follows:
According to the situation of chipping, if the chipping is very small, it is usually necessary to grind the chipping portion with a grinder to ensure that the welding is firm and not easy to chip again.
Welding with the corresponding welding rod, we are currently using D332 welding rod to surfacing the cutting edge. Be sure to select the repaired reference surface before surfacing, including the clearance surface and the non- clearance surface.
Flatten the non-gap surface of the cutting edge (refer to the baseline left in advance)
Dash the control transition piece, if there is no transition piece, you can use the previously left reference to rough the clearance surface.
The upper machine can be repaired by the gap surface, and can be assisted by clay or the like. Be careful during the repair process. When starting the press, try to be as slow as possible. If necessary, adjust the height of the stamping dies to open downwards to avoid the occurrence of rupture of the knife edge.
The gap between the edges should be reasonable. For the stamping die of the steel plate, the gap of the edge of the single edge is taken as 1/20 of the thickness of the sheet. However, in the actual operation process, the size of the gap can be checked by the method of
sheet metal test, as long as the burr of the part after cutting reaches the requirement, in general, the criterion for determining the size of the burr is that the height of the burr is not greater than the board. 1/10 of the thickness of the material.
Check whether the gap surface of the knife edge is unified with the direction of shearing.
After the gap is matched, use the oil stone to smooth the gap surface of the knife edge to reduce the friction between the sheet and the knife edge in the production and the falling of the scrap.
3.Scratch
Knife edge chipping mainly occurs in the processes of drawing, forming and flanging.
Solution
1. First find the position of the corresponding napping of the stamping dies against the part;
2. Use the oil stone to push the corresponding position of the stamping dies, paying attention to the uniform size of the rounded corners;
3. Polish the stamping dies with a fine sandpaper, and the sandpaper is above 400.
4.Trimming and piercing strips
The main reasons for trimming and punching are: abnormalities in the die or unloading device of the mold during trimming or punching.
Solution:
Find the corresponding part of the mold according to the part of the strip;
Check the mold pressure release plate for abnormalities;
Repair welding the corresponding parts of the pressure plate;
The welding parts are repaired by combining the parts, and the specific profiles and process parts are prepared;
Test run
If the inspection is not a problem with the stamping dies press plate, you can check if the die of the stamping die is napped.
5.Waste cutting
In view of the continuous phenomenon of waste cutting, we first analyze why it is cut continuously. The main reason is that the operator does not clean the waste in time during the production process, resulting in the accumulation of waste. Finally, the scrap knife is caused by the pressure of the upper trimming block. The method of repairing is similar to the method of trimming and chipping. It will not be described in detail here, but only during the repair process.
Be sure to pay attention to the height of the trimming block. If it is repaired too high, it will cause the knife block to interfere with the upper trimming block, which will cause the scraping of the scraping block again. If the repair is too low, the waste cutting will be formed continuously, so it is necessary to consider not only the cutting block when repairing the scraping knife. The clearance surface and the height of the block are also important. The difficulty of repairing is more difficult than the simple blade edge. But as long as the datum is selected before repair, it can still be repaired.
6.Burrs
When the parts are trimmed, punched and blanked, the burr is too large. The main cause of the burrs is the large gap between the die edge and the small gap between the edges:
When the gap is large: the section of the bright band is small or substantially invisible, and the burr is thick and large, and is difficult to remove;
Hours of clearance: Two bright bands appear in the section. Due to the small gap, the characteristics of the burrs are high and thin.
Repair method when the gap is large
1. The trimming and punching process uses the method of trimming the die to fix the die, and the blanking process is based on the die, that is, the die size is unchanged, and the punch is trimmed. The above difference is to ensure that the product size is not affected before and after repair;
2. Find the part with large clearance of the cutting edge of the die against the part;
3. Repair the part with the corresponding electrode (D332) to ensure the hardness of the die edge;
4, repair the knife gap (the method is the same as the knife edge chipping method).
Repair method with small gap
1. The specific situation is adjusted according to the size of the stamping die gap to ensure the reasonable clearance. For the trimming punching die, the method of placing the gap in the die is adopted, and for the blanking die, the method of enlarging the punch is adopted, thereby ensuring that the size of the part is unchanged before and after the repair;
2. After the repair is completed, measure the vertical of the gap surface and use the plate to test whether the gap is reasonable.
For the punching die, after the burr is generated, if the punch or the die is worn, the corresponding standard part can be replaced, and if there is no standard part, it can be manufactured by repair welding or mapping. In addition, it is pointed out that for materials with poor weldability such as alloy steel materials, special treatment is required before welding, such as preheating, otherwise the stamping may be cracked.
7.Punching waste blockage
Punching waste clogging is a common type of failure in punching dies. The reasons are probably: the scrap road is not smooth, the scrap road has a reverse taper, and the scrap is not cleaned in time.
Reason
1. The stamping die is not smooth, and the processing pattern appears on the surface;
2. The stamping die has a reverse taper, which causes the waste road to be large and small and the waste is clogged.
Repair method:
As long as the A and B sides are in a smooth and equal diameter state, the waste will not be blocked.
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