Steel barrel seam welding
In 1997, we developed a milling machine to replace the edger in steel drum production. It has been successfully used in Lanhua Metal Products Factory.
In the production of steel drums, the edging process is mostly used in the past. It has many shortcomings, such as: high noise, dust, and high energy consumption. Especially for galvanized sheets, the edging machine is powerless, and the small zinc powder will fill up quickly. The surface of the grinding wheel makes the grinding wheel dull and cannot be produced normally. The milling machine succeeded and completely changed this-cut.
Now compare the general eight-head edging machine with the edge milling machine:
No. Comparison item Edger milling machine 1 Power head number 8 4 2 Conveying device 1 set 1 set 3 Feeding mode chain claw type to roller type 4 Power consumption is greater than 27KW 6.6KW 5 Feeding speed is not less than 6 m / min 5 Meter / minute 6 cutting depth 0.05 ~ 0.1mm
7 Noise is greater than 100 decibels less than 85 decibels 8 Dust is large 9 The galvanized sheet can not be processed and processed 10 The floor area is more than 15 square meters and less than 5 square meters
From the above comparison, the superiority of the edge milling machine is obvious, its power consumption is only 1/4 of the edger, the noise is less than the edger, more than 5 decibels, and no dust, greatly improving the workers. Labor environment.
In the development process, we feel that the difficulty in realizing the processing of thin steel welds by milling is that: (1) the rigidity of the workpiece is poor. (2) The amount of feed required for milling is large. (3) It is easy to tear the steel plate when cutting and cutting.
Under normal circumstances, the cutting depth of milling is large, generally 212mm, and the cutting feed is small, generally between 0.3 and 1 m / min, but the opposite is true when dealing with steel barrel welds, the depth of cut is very Small, only 0. 1 ~ 0.5 mm. The feed rate requirement is very large. It is also required to be 4.5 m/min according to 5 minutes and 200 liters of barrels per minute. To achieve such a large feed rate, the spindle speed must be increased. In order to simplify the power head structure and lubrication device, set the spindle speed to 1500 rpm, the cutter head diameter is 40 mm, and the clamping blades are 4, then the feed rate per blade is SZ = 5000/1500 X 4 = 0.83 mm. .
When the tip width is 1.2 mm (>0. 83 mm), no scratches are left and the milled surface is smooth. We use Zhuzhou Cemented Carbide Factory products SPCN1203EDL, SPCN1203EDR hard non-re-grinding blades, the effect is very good.
The thickness of the steel plate for the barrel is only about 1 mm, and the rigidity in the thickness direction is small. This is very detrimental to milling. If the steel plate is in a free state, the milling edge can not be carried out at all. Our method is to set two elastic roller pressing devices close to the milling cutter to press the steel plate on the rail, the pressing force is adjustable, and the pressing is tight. The force is based on the principle that the steel plate does not vibrate and does not affect the feed feeding.
When doing the process simulation test, it was found that when the milling cutter cuts in and exits the steel plate, the corner of the steel plate is easily torn, because the rigidity of the steel plate corner is smaller and the feed amount is too large. When the feed rate is reduced to 3 meters per minute, the phenomenon of tearing angle is not repeated. In order to ensure production efficiency, the feeding device uses a two-speed motor. When the tool is cut in and cut out, the feeding is 2 mm. At 68 m/min, the rest of the feed rate is 5.37 m/min. After this treatment, the milling can be guaranteed to proceed normally. The average milling speed is also up to 5 m/min, which basically meets the requirements of an annual output of 300,000 barrels.
In the actual production, the 200 liter closed steel drum is taken as an example, and the edging depth is 0.05 mm. After seam welding, the thickness at the lap edge is close to twice the thickness of the barrel. Therefore, after the hemming, a "triangular zone" is formed, which is extremely easy to leak; this is a major problem in the barrel industry. In order to eliminate the "triangular area", some manufacturers use the grinding wheel artificial grinding method to grind the welds at both ends of the barrel ring after the seam welding of the barrel ring. Some manufacturers try to solve it with "extrusion trimming", but Investment is difficult.
If the edging depth is larger, the total thickness of the lap portion after the lap overlap is close to the thickness of the barrel, then the "triangular area" will certainly not appear, but the edging depth is increased, which is currently the edging machine. Not enough, now the edging machine is mostly 8 and 12 (ie 8 and 12 grinders), with 12 heads on each side, each grinder has a depth of 0.02 mm, total grinding depth It is also only 0.12 mm. If the grinding depth is to be increased, the steel plate is extremely easy to burn and the milling is different. There is no depth limitation. The milling depth can be adjusted so that the overlap thickness of the lap edge is close to the thickness of the barrel plate, thereby eliminating the "triangle area". Improve the quality of the curling.
In addition, we designed the milling power head to be movable. According to the length of the steel drum of different specifications, the distance between the two sets of milling heads and the guide rail and guiding device can be adjusted. On a milling machine, 80 liters can be used. The 100-liter and 200-liter steel drum sheets are milled and processed to expand the range of machine tools.
Author unit: Xi'an Machinery Research Institute
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