On the occurrence and overcoming methods of the fi

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The occurrence and overcoming methods of five layer flat curling defective steel barrels (Part 1)

the defective steel barrels mentioned in this paper refer to steel barrels that do not meet the quality standards of first-class products and are not limited to specifications, varieties, capacities and thin and thick materials. Here, I will not discuss the seriousness of these defective products and the possible consequences. This paper mainly discusses the causes of steel drum curling problems and the methods to overcome defective products. Strive to achieve the purpose of no or less defective products in production through discussion, so as to improve the product quality and the technical level of operators. The following discusses the causes and solutions of sixteen kinds of flat crimping defective products:

first, there are hard edges on the back of the crimping (Fig. 1)

during the production process of steel barrels, sometimes there are hard edges on the back of the rolled edges of the assembled barrels. The severity is different. When it is serious, the barrel cannot roll down smoothly, and even it is wrapped on the sealing disk. The causes and solutions of the problems are as follows:

1 The bottom cover roll is too low

the bottom cover roller should have been installed on the side of the sealing wheel, and the upper end should be slightly lower than the sealing disk. Because the installation is too low or the fastening bolts of the supporting roller are loose, there will be hard edges when the supporting roller cannot play the role of the bottom cover. At this time, lift up the supporting roller or retighten the bolt, and the hard edge can disappear

2. The sealing disk is not correct

due to the improper installation of the winding disk, it will jump up and down when rotating. At this time, half a circle of hard edges are easy to appear on the drum curling edge. Readjust the winding disk so that the jumping disappears and the hard edges also disappear

3. The winding disc is worn

hard edges will also occur when the acute angle at the lower end of the winding disc is worn to a certain extent during long-term continuous production. Due to uneven quenching after welding, the coil sealing disk repaired for many times will fall off locally during production, which will also cause this problem. The sealing disk should be replaced in time

4. The overlap of can body weld is too wide

domestic welding machine can be produced only when the can body is wide and overlapped. At this time, if the sealing wheel is adjusted tighter, hard edges can appear on the back at the junction of straight seam and curling circumferential seam. If the adjusting screw rod of the wheel is slightly loosened, the problem can be eliminated after the loading speed indicator is pre selected

II. Sharpen the top (Figure 2)

this problem refers to the whole circle or local wear of the crimping top. The reasons for the increase of cooperation projects between the two countries in these fields and the solutions are as follows:

1 The arc design of the sealing wheel

according to experience, when the arc slope of the sealing wheel is designed to be large, using this wheel for sealing is beneficial to the thin steel barrel, mainly because it can make the curling tighter, but if it is adjusted too tightly, the problem of top grinding can also occur. Therefore, attention should be paid to the proper tightness of the rotation. It is not suitable to use the wheel designed by this method to produce thick steel barrels

2. Poor lubrication

when spraying barrels in production, because the bottom cover of the barrel is pickled, the grease on the surface of the barrel plate falls off, so the friction between the wheel arc and the steel plate increases during sealing, causing the top to be sharpened. Horizontal sealing machines with high production speed are more likely to have similar problems. This problem can be avoided by spraying saponification liquid on the wheel arc and increasing lubrication during sealing

3. The supporting roller is in an improper position

when the bottom cover roller is installed too high or too far away from the winding disc, there may be a problem of grinding the top. After proper adjustment, normal production can be resumed

III. can body side valgus (Figure III)

can body side valgus, also known as iron tongue. Vertical sealing machine or horizontal sealing machine may occur. The causes and solutions of the problems are as follows:

1 The barrel body turns over and bumps

semi finished products of galvanized barrels are generally galvanized by external units. Due to the repeated handling of the barrel body, some of the flanging parts of the barrel body collide and deform. Before assembly, this part was not leveled with a wooden hammer, resulting in the problem of can body side eversion after sealing. The fundamental way to solve the problem is to take effective measures to prevent the bucket edge from bumping

2. The idler (bearing) is accelerated to be implemented in the Hostalen process unit of PetroChina, and the utilization and installation are too high

when the horizontal sealing machine is operated, sometimes the curling occurs intermittently with a long iron tongue greater than 10 cm. At this time, it should be judged that the supporting roller (bearing) supporting the bottom cover edge is installed too high. Because the supporting roller position exceeds the bottom plane of the winding disk too much, after the can body is clamped, although the winding wheel has not acted, the edge of the can body has been bent and pried up, causing iron tongue after sealing. At this time, the supporting roll should be adjusted backward. After an appropriate amount, the tapping tongue problem will disappear

IV. bottom edge or cover edge eversion (Figure 4)

when the barrel bottom cover and barrel body are sealed, there is a small section that cannot hook the barrel body flanging, but is exposed outside the flanging, which is also called iron tongue. The causes and solutions of the problem are as follows:

1 The bottom cover edge is bumped

this problem occurs when the bottom cover edge is pried up due to collision before assembly, and the deformed part is not flattened with a wooden hammer during assembly. Effective measures should be taken to prevent bumping against the edge of the bottom cover

2. There is too much hot metal for repair welding after the edge of the barrel is cracked

after the barrel body is sewn by the welding machine, the flanging at both ends of the barrel sometimes cracks. When repairing welding, if too much molten iron is used, it will become thicker here. During sealing, the excessively thick flanging will be pushed outward from the cover edge, causing iron tongue at the junction of straight seam and ring flanging. In order to prevent the occurrence of iron tongue, try to reduce the amount of molten iron during repair welding, and grind the excessively thick part with hand grinding wheel

v. tapping tongue and wire cutting (Fig. 5)

tapping tongue and wire cutting sometimes occur at the same time, sometimes they can also occur alone, but they are different from the third and fourth types of tongue mentioned above, which is a whole circle of tongue and wire cutting. The causes of the problems and the ways to overcome them are as follows:

1 Use the wrong roll sealing wheel

this problem often occurs in steel drum assembly workshops with many varieties and specifications. For example, the steel barrel material made is m thick. If the winding roller with a plate thickness of 0.8mm is misused, this problem occurs when the winding roller is fed to a certain extent. The reason is that the lower curling edge is contained in the wheel arc, so it is necessary to put an end to the random copying and use of the winding wheel, and the marking and storage of the winding wheel should be done well

2. The arc of the winding wheel is not satisfactory

when the wheel arc is not well designed, the fire is improper, and the rolling arc after machining does not conform to the template, wire cutting is easy to occur. Overcoming method: replace with a new wheel when the wire cutting is serious. When it is slight, loosen the locking nut of the roller for a few buckles to make the wheel swing to a certain extent. When the wheel arcs are worn together, the problem will naturally disappear

3. The leveling wheel is misaligned

for the grooved flattening wheel used in sealing, when the wheel support is adjusted too much lower than the bottom plane of the sealing disk, a whole circle of iron tongue can occur. At this time, the wheel should be raised, and the whole circle of tongue can disappear

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