Processing of the inclined loop tube of the hottes

The processing of the loop inclined tube of the carding machine

1 overview

the carding machine is one of the important equipment in the spinning process. In the spinning production process, the loop forming mechanism is to output the cotton sliver or wool sliver and other large pressing rollers, which are pulled and pressed by the small pressing rollers to form a certain loop, and the loop inclined tube is regularly placed in the barrel for the next process

the coil inclined tube is a casting, made of HT300, and its shape is shown in Figure 1. It is required to contact the cotton sliver after processing, as shown in Figure 1 Φ 38. The inner surface, end face, reverse hole inclined plane and its intersection line of the through hole must be free from hanging flowers and stinging flowers, that is, the roughness of these surfaces must not exceed Ra0.8 μ m。

2 process

in order to avoid drilling on the inclined plane, the process boss is designed, as shown in sketch 1. This part has a large size, special shape and high processing requirements, so it needs to be processed on the existing machine tool with innovative process. Its process flow is ① accurately determine the center position of the hole on the process boss, punch the sample, and mark out the correction as early as May 24 last year, It is convenient for the installation, alignment and positioning of complex workpieces on the machine tool. ② The welding lengthening of three claws on C620 lathe is changed to external claws to clamp the workpiece and process the outer ring and end face. When machining the end face, leave a finishing allowance of about 0.1mm, and then grind the end face with an oilstone to achieve the roughness Ra0.8 μ m。 ③ Use four claws to clamp the fixture with workpiece on C630 lathe, and process the hole based on the center position and correction circle of the process boss hole. ④ On the C620 lathe, process the parallel flange surface, turn off the process boss and reverse the hole slope. ⑤ Finally, polish the hole surface and intersection line

3 fixture

(1) the three jaw chuck of C620 lathe is lengthened by welding, turning out the positioning seam, and changing it to a new reverse jaw, as shown in Figure 2. The size should ensure that when clamping the workpiece, the size does not interfere with the workpiece, the workpiece rotation diameter increases, and the linear speed is correspondingly high, so choose a smaller speed, and the lathe spindle speed is 50-60 rpm

(2) the design of C630 four jaw chuck fixture is shown in Figure 3. The main body of the fixture is welded with ordinary steel plate with plate width of b=430mm and plate thickness of t=15mm. The flange surface of the workpiece is positioned in the fixture hole, and the workpiece is pressed with 4 uniformly distributed pressing plates. The four jaws are adjusted, and the workpiece must be processed Φ 38. Only after the rotation axis of the inclined hole is corrected to coincide with the rotation line of the lathe spindle can the hole be drilled, otherwise, the pipe wall may be punched and discarded. During processing, the whole workpiece, including the fixture, is eccentric, so a balance block should be added. After the test, if there is no reaction block for the rising and falling buttons of the balance pair, it is Φ one hundred and ten × Two 75 cast iron blocks are symmetrically connected to the main body of the fixture with M12 set screws, and the ring is turned by hand to confirm that it is OK, then the lathe can be started for processing by 30 college students from Zhejiang University of technology

4 hole processing

in order to avoid drilling on the inclined plane, the process boss is designed as shown in Figure L. when drilling deep holes, the guidance of the drill bit is poor, and the drill bit is easy to deflect during drilling. Therefore, the front or rear face of the drill bit should be ground into a chip separation groove to make the chips broken and easy to remove chips. Adjust the workpiece on the C630 lathe, and the taper handle fried dough twist drill Φ 37 directly insert it into the tailstock sleeve of the lathe to process the through hole, and the speed of the drilling spindle is 200 rpm. When drilling through, due to the uneven force on the inclined plane, to prevent the drill bit from being damaged, the speed should be reduced to 50 rpm. At this time, the feed rate should also be small, and when drilling, the drill bit should be constantly pulled out for chip removal

use boring bar as Φ 33. The tail end square head and blade are in the shape of a pointed knife clamped on the tool holder and bored out Φ 37.8 hole, at this time, the spindle speed is 50 rpm, and then use the reamer rod to Φ 36. Six edge YG8 and 60 long cutting edges are ground on the universal tool, and are directly installed on the tool holder with a cone sleeve. The speed is 20 rpm, and the oil + diesel (1:1) cutting fluid is frequently added for lubrication and cooling

the final processing of the hole is to reverse the hole to form the sharp part of the included angle between the inclined plane and the end face, polish it with a semicircular file, and then polish it with fine sandpaper, so as to achieve no hanging or tingling

5 face grinding

because grinding this irregular workpiece on a surface grinder requires the design and manufacture of more complex fixtures, innovative processes are used. It is directly processed on C620 lathe by using 10mm thick wooden board to pad 200 × fifty × 20 under the oilstone, put it into the tool holder, put the knife iron plate on the oilstone, clamp it with the set screw, and start the lathe. The spindle speed of the lathe is about 50 rpm. Ra0 can be ground with the end face of the oilstone, so it needs to be disassembled and converted to a new one.8 μ The end face of M is ground with a small amount of machining from the front, and cooled with oil. Finally, it needs non sparking grinding

6 after processing, the static balance must be verified, and the "t" shaped reinforcement can be drilled or the balance weight can be increased

7 conclusion

on the ordinary lathe, plane grinding is carried out by improving the process. Practice has proved that this is an effective method with simple cost and certain performance requirements. It is worth using for reference in similar occasions