Tool improvement in the manufacture of the hottest

2022-08-07
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Tool improvement in compressor manufacturing

compressors have a wide range of applications, including petrochemical, metallurgical, textile, aerospace and other fields. A compressor is often composed of hundreds of parts, with complex manufacturing process and high technical requirements. In order to meet the production needs of various parts, the reasonable allocation of cutting tools and tooling fixtures is very important. In order to meet the requirements of good, fast and economical production, some cutting tools and tooling must be improved and designed. Here are three examples:

milling clutch flange cutter and tooling improvement

the shape of the one-way acting helical tooth clutch is a helical end face tooth structure, which is used to automatically disengage when the transmitted torque exceeds a certain value, so it is also called a safety clutch. The most commonly used machining method on the milling machine is the indexing head change gear method. The change gear is calculated according to the lead (the lead is 16), and the appropriate change gear is configured between the indexing head and the workbench to realize the uniform rotation and uniform linear motion of the workpiece, so as to process the Archimedes curve surface; But its disadvantage is that it needs to replace three groups of change gears and an intermediate wheel, and the position of the driving wheel and the driven wheel cannot be reversed, which is very cumbersome in the operation process. Tool selection Ф 8~ Ф 10. For end milling cutter, the cutting edge of the milling cutter shall be tangent to the axis of the workpiece during tool setting. When the tool is lowered to the required depth during operation, the indexing handle shall be inserted into the hole of the indexing plate, and the indexing handle shall be shaken for 20 circles. While the indexing head rotates, the workbench shall be fed longitudinally to make the workpiece move in a compound manner to obtain the spiral groove; Raise the tool, turn the dividing head handle in reverse for 20 turns, pull out the pin, continue to shake the dividing handle for 20 turns, insert the pin, and repeat the above steps to process another spiral groove

the above processing methods are time-consuming and laborious, and can not be processed at one time to meet the requirements of the drawing. The tool radius is reserved at the tooth root. It is necessary to manually file the tooth root to keep r0.5, which is inefficient and the accuracy requirements cannot be guaranteed

for this phenomenon, the author has been considering whether the processing can be completed at one time and meet the drawing design requirements. After careful analysis and CAD aided design, it is decided to thoroughly improve the original cutting tools and tooling. The tooling was designed by the author and experienced teachers in only two days, and the drawings were handed over to the relevant departments for processing. After theoretical calculation, the geometric angle and shape of the tool have begun to take shape. Many search results are really not what the user is looking for. The problem is how to process the tool. For this reason, our factory specially carries out bidding, and two qualified tool manufacturing enterprises participate in the bidding. Among them, one company proposed to order 200 pieces at a time, and the unit price was about 200 yuan. A batch of cutting tools totaled about 40000 yuan. The manufacturer also refused to make small quantities of custom-made test tools; The other one went directly to the local market and said that one can be customized, but the unit price must be 2000 yuan and the delivery cycle is long

after careful consideration, we finally decided to undertake the task of tool restructuring by ourselves. The existing universal tool grinder in the workshop is used for processing, and the domestic high-speed steel is used Ф One stall owner of "22 taper shank large spiral end milling cutter" replied to carry out restructuring. First, grind the front end of the milling cutter into an inverted taper with a single side inclined by 8 °. Then, the rake angle shall be polished to increase the space of the chip holding groove (according to the shape and machining characteristics of the chip holding groove, it is specially compared with a Japanese brand tool, and it is found that the cutting effect is far better than that of the Japanese brand tool. For details, it is briefly introduced in the second part of the straight shank end milling cutter), so as to avoid the phenomenon of chip accumulation during rapid milling with increased tool travel. The last process is to grind the back angle. If the back angle is too small, the workpiece cannot be cut, and if it is too large, it is easy to break the cutting edge of the tool. Therefore, for the machining occasion of this cutter, the back angle is selected as 8 °. After the quenching and tempering of 45\

the structure and principle of the tooling are briefly introduced here. Its main components are screw rod, right-hand helical cylindrical gear, bolt, underframe, etc. the lead of one revolution is 16

its working principle is to turn the hand wheel clockwise and drive the screw rod to rotate, so as to make the helical cylindrical gear rotate counterclockwise (according to the force analysis of the helical gear, when rotating counterclockwise, the axial force F is upward). When rotating for one cycle, it will rise one lead. The structure is simple, convenient and practical

after the cutter is installed on the spindle of the milling machine, turn the end milling head clockwise by 7.5 °. The tooling is horizontally clamped on the workbench of the milling machine, and the parts are installed on it. The results obtained after the trial machining are shocking. The whole spiral flange surface is machined in only 5 minutes, the efficiency is 5 times higher than the original, the tool durability is 2 times higher than the original, the cutting edge is polished once per 200 machining, and the reuse rate of a single tool reaches 10 times; And all standards of the parts fully comply with the drawing requirements. Before that, the spiral flange surface was also tried to be processed with ball end milling cutter in the three-axis linkage vertical machining center (the end milling cutter interferes with the processing of spiral surface). Not only the processing time is long, but also the radius of tool ball head is reserved at the tooth root, which needs secondary processing. Of course, this tool can also achieve the desired effect when machining clutch flange in machining centers with more than four axes

improvement of straight shank end milling cutter

the packing chamber is made of 2Cr13 high-quality stainless steel, with an annular groove 12mm wide, 20mm deep and 200mm diameter on the end face, as shown in Figure 4. Initially domestic Ф 1. The spray free material can replace the traditional environmental protection material. 2. The high-speed steel straight shank end mill is processed with a cutting depth of 5mm at a time. After less than 5 minutes of processing, the chips adhere to the teeth of the milling cutter, which worsens the cutting conditions and causes the milling cutter to collapse. During processing, the cutter is changed frequently and the efficiency is very low. It takes 150 minutes to process an annular groove. After that, the Japanese Mitsubishi carbide milling cutter was used. Although its performance was better than that of the former in all aspects, there was still a problem of chip accumulation in the chip holding groove. During automatic machining on the machining center, the blade broke or even the tool broke. Because the cost of each tool is about 1000 yuan, the processing cost is very high, which brings great waste to the enterprise. It is difficult to find a suitable tool to replace it

the author analyzed the above cutting tools and found that the reason for iron filings congestion and poor chip removal is that the chip holding groove is small. Then, can the width and shape of chip groove be tolerated on the original basis? This method is worth trying if it can be solved by changing the width of the chip holding groove and some angle problems according to the above idea. The author immediately put into work, adjusted the tool grinder, sharpened the chip holding groove, widened it by 10% on the original basis, and made the arc of the groove as smooth as possible, which was more conducive to chip removal. The working rake angle of the milling cutter is increased to about 25 ° to make the milling easier, but the value should not be too large to avoid weakening the strength of the cutter teeth

after the cutting test for the workpiece with a cutting depth of 10mm, the cutting is very stable. There is no chip adhering to the milling cutter teeth during the whole machining process. The machining takes 20 minutes. However, the required depth of the workpiece is 20mm. According to conventional processing, the depth generally does not exceed half of the diameter of the milling cutter, which is a supplement to DSC, infrared and X-ray fluorescence. Can it be directly processed to the required depth at one time? Most domestic 12mm milling cutters have a blade length of about 25mm. Whether they can withstand full cutter milling will be another test. During machining, 10y cutting oil is used for high-pressure cooling. The milling depth reaches 20mm. The expected effect is achieved after one-time machining, and the time is less than 50 minutes. The machining speed is doubled on the original basis. The milling cutter after secondary improvement is superior to the imported cutter in terms of cutting conditions and feed depth. The tool cost is only 15 yuan, which is 1/30 of that of imported tools (conservative estimation, imported tools are generally about 500~1000 yuan). In addition, the auxiliary time for tool change is saved, and the comprehensive processing benefits are significant. Compared with imported tools, domestic tools do not have much problems in materials. As long as some time is spent on geometric angle and grinding, they can be comparable to or even better than imported tools. After secondary improvement, ordinary cutting tools are used to replace imported cutting tools. The processing speed is nearly twice that of imported cutting tools, and the annual tool cost is saved by more than 100000 yuan

improvement of ordinary high-speed steel keyway milling cutter

keyway machining is very simple in metal processing, but the larger the milling cutter diameter, the greater the resistance to downward drilling. For this reason, the author grinds the end cutting edge of the milling cutter according to the principle of group drilling. The two cutting edges are ground into several alternating sawtooth chip separation grooves, and the blind holes are vertically drilled on the machining center. The effect is very ideal. Several auxiliary cutting edges are added to the original two cutting edges, which greatly reduces the friction coefficient and cutting resistance between the tool and the workpiece, and the shape of iron chips is changed from the previous flake to the strip chip breaking, At the same rotating speed, the tool travel is 3 times of the original

at present, the performance of domestic tools has become closer and closer to that of imported tools, and the cost performance of some domestic tools is even better than that of imported tools. Our factory has greatly reduced the production cost through the extensive use of domestic cutting tools. In order to meet the needs of the new era, we must develop advanced manufacturing technology, promote scientific and technological innovation with advanced manufacturing technology, improve the overall design level and product R & D capability of enterprises, reduce R & D costs, and improve the technological innovation capability of enterprises and the manufacturing technology level of China

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