Lecture of steel Drum Production Line Training - Four

Five, blanking and Causes of Common Defects during steel drum production

Blanking common defects are: burr, uneven workpiece surface warpage, dimensional precision ultra poor.

I Glitch

In punching, resulting in different levels of glitches, in general, it is difficult to avoid. The factors are the following.

⒈ gap

Blanking gap is too large, too small or uneven, can produce glitches. Resulting gap is too large, too small and uneven factors:

⑴ working part of the dimensional accuracy of the mold does not meet the requirements of the die drawing.

⑵ punch or die with anti-tip (anti-cone), so that the gap during blanking changed.

⑶ guide portions large gap. If the guide post and bushing with the gap or wedge between the guide plate blanking gap is too large can cause changes in the gap during blanking.

⑷ assembly error. Such as punch and punch fixed plate assembly vertically, or punch holes mating portion and the fixed plate is worn, or fixed die punch or a positioning pin position allowed, will result in the punch and die relative position deviation leaving uneven gaps.

⑸ installation error. The top and bottom surfaces, such as die during installation is not clean, or screw fastening the upper mold caused by improper working part tilt.

⑹ die structure is irrational. If the die or insufficient rigidity of the working part die, deformation occurs during the blanking gap affecting changes. Or to offset the lack of punching lateral forces generated during briquetting opposite side, so that the relative displacement produced a working part.

⑺ presses rail gap is too large, the slider bottom parallelism with the table is not good, or the direction of motion of the slide table and presses the vertical well.

⑻ sheet metal scoop large curvature in the blanking process, so that the smaller diameter punch tilted.

⒉ blunt edge

Worn or bite wounds stamping.

⒊ improper positioning height

Trimming punch, if the depth below the workpiece positioning height, in the blanking process, workpiece shape and edge burrs will Unruly.

⒋ improper mold structure

Due to lack of the necessary pressure device, a single-sided punching, especially thick in the blanking process will produce greater tensile stress, elongation and tensile metal fibers, resulting in blanking fracture surface roughness, there was a big glitches.

Burrs, not only in the subsequent deformation processes prone to cracking, but also to the sheet feeding caused hardship layering and dimension, and exacerbate edge wear, reducing the life of the mold and the generation gap riveted or welded to wear, weld defects such as unsound . Burr also in the process of production and use of scratch operators, threaten personal safety. If the parts have appeared outside the allowable range glitch, it should be eliminated. The most commonly used method to eliminate glitches is tumbling.

(Ii) warping uneven parts

Cause:

⒈ blanking clearance larger. Gap is too large, it is prone to warp.

⒉ die hole with anti-tip. Parts of the site through the small size, the outer compression with the center, resulting in bending.

⒊ workpiece itself warping. When the complex shape parts, the parts surrounding the uniform shearing force, leaving parts warping. The solution is to increase the binder force, punching before compression, and then did as fine blanking blanking, can achieve good results.

⒋ material warpage generated internal stress. Sheet material in the rolling, winding the resulting internal stress transfer to the surface after punching, parts warping will occur, so the stress will eliminate it before processing. Can leveler straightening or annealed to remove, may also be processed leveler.

⒌ the oil, air and debris warpage. Between the die and the parts of oil, air, debris and other pressure parts, the parts will be warped, particularly for thin, soft material influence.

(Iii) the dimensional accuracy tolerance

⒈ mold manufacturing cutting edge dimension tolerance.

⒉ mold during rebound.

On the procedures of the workpiece shape and mold the rebound surface shape of the working part is inconsistent, making parts in the blanking occurred during deformation, affecting dimensional accuracy.

⒊ edge wear or improper adjustment.

Multi-process of the workpiece, as the last procedure to adjust the depth of improper or fillet worn, destroyed the principle of equal volume deformation, causing changes in the size.

⒋ positioning feet.

Since operations bad positioning, or positioning mechanical design bad happened during blanking traverse rough, cut pieces of defects (prismatic degrees, lack of edge, etc.) can cause inaccurate positioning due to size tolerance.