I heard Yang Bingbiao say that this lathe guide rail, which is more than one meter long, has actually reached the third level. If you give them time, you can't even do it with a second or even a first level under the most common basic tools such as scrapers, files, and sandpaper stones!

The more advanced the machine tools, the fewer they exist in this world.

In Yunfei's world, looking through the entire earth, it is estimated that there are not many metal processing machine tools with an accuracy level of more than two levels. Not only because these machines are made by the oldest manual method at an unacceptable price, but also because there are not many super-precision machines on the entire planet that need these super-precision machines.

The parts produced are used to assemble with other parts, and if the parts really reach the accuracy of more than three levels, it will be difficult to assemble because the gap in the assembly place is too small. Of course, it becomes more and more difficult to adjust the assembly gap of the system.

"Now that the machine bed has been processed, it's ready to be transferred to the assembly workshop." Yun Fei saw that there was hardly a trace of processing on the machine tool, and the inverted V-shaped protrusion part and the flat part of the jump guide rail were vaguely able to reflect the shadow of a person as if it were a mirror.

The straightness of the guide rail with three levels of precision is within 0.008mm, and the flatness is also within this tolerance, of course, the parallelism will not exceed a trace. The V-shaped groove and plane under the saddle mounted on the rails are also accurate.

Yun Feizhi said that at the beginning, these parts were not assembled, but scraped separately, and then when the size was about to be detected with various tools, the accuracy level was at least close to the fourth level, and the workers would overlap the assembly positions of the two parts. Grind back and forth on the rails with the saddle that drives the knife holder to move.

Due to the high hardness of the plane of the guide rail, especially when the two planes are smooth, it is not easy to wear the plane of the fit by pushing the saddle on the guide rail of the machine tool to grind back and forth. Therefore, the saddle that was originally only tens of kilograms must be counterweighted, and under the reuse of gravity, the two planes that rub against each other will become smoother and smoother. Of course, the counterweight added to the saddle and the gravity added to the saddle must be balanced. Otherwise, the flatness of the grinding mating plane will not meet the requirements at all.

On the machine, there is not only the guide rail and the saddle mounted on it to drive the tool holder to move, but also the saddle that needs to be used to achieve the highest precision. The knife holder is not mounted directly on the saddle, but there is also a center plate on the saddle for longitudinal movement with the knife holder. The saddle carries out lateral movement with the tool holder, and the middle support plate drives the tool holder to move longitudinally, and when the lateral and longitudinal movement are carried out at the same time, the movement trajectory of the tool will be an oblique line, or an arc.

The tool moves diagonally, which is used to turn the taper; When the trajectory becomes an arc, the arc is cut.

Manual operation by workers. It is difficult to achieve a uniform change in both directions, but this problem does not exist with CNC machine tools. CNC machine tools were not originally used to produce large quantities of parts, but to process various complex movements that were difficult for these manual operations to achieve.

It is also a nine-level fitter with the best skills of Jiuyi Heavy Industry. However, the workshop is not a precision machining workshop, but a dust-free workshop that has not been opened since its completion to carry out the assembly of CNC machine tools. In fact, this dust-free workshop is not a dust-free workshop in the real sense, but the whole plant is basically in a sealed state. With the exception of a few windows for ventilation, most of the windows are closed.

At this time, there was no large-scale central air conditioning production in China, thousands of square meters of factory buildings. If you want to achieve constant temperature conditions, such a central air conditioner must be customized abroad, and that price is not at all affordable for the current Yunfei.

In the thousands of square meters of factory building, there is a lathe foundation equipped with the foot of the bed, the bed, and the headstock. Four or five ninth-grade fitters in their forties and fifties in white coats, under the leadership of Yang Bingbiao and Guderian, orderly loaded all kinds of spare parts into the headstock of the lathe.

"Lighter, don't use it as an ordinary lathe to assemble ......" At the assembly site, seeing those old hairy people in the assembly, Yang Bingbiao's heart was about to fall out.

You must know that these parts are at least one level higher than the accuracy level of those ordinary lathe parts, and some of the main parts in key positions have even reached the accuracy of level 5.

None of the workers in this group have ever assembled a lathe with such a high accuracy level of parts, and of course, no CNC lathe.

Yun Fei originally wanted to go to other machine tool manufacturers to dig one or two ninth-level fitters with experience in CNC machine tool assembly, but those people were treated as treasures in their factories, and those factories would not be stupid enough to give their masters to their competitors. Originally, I heard that Zhao Xingbang had a bad relationship with the director of the Northeast No. 1 Machine Tool Factory, and Yun Fei wanted to get one or two from the No. 1 Machine Tool Factory in the Northeast through Zhao Xingbang, but before the words were spoken, Zhao Xingbang hung up Yun Fei's phone.

The director of the No. 1 Machine Tool Factory in Northeast China directly called Yun Fei to threaten Yun Fei that if Yun Fei again started digging into the mind of their factory master, he would do whatever it took to pull the engineers and various senior workers that Yun Fei had worked so hard to get back from the Soviet Union into his factory.

Yun Fei knew that the threat of that goods must be taken seriously. Northeast No. 1 Machine Tool Factory, is the largest machine tool manufacturer in China, in the world of Yunfei, that era, the annual sales of CNC machine tools are close to 10 billion US dollars. Coupled with the title of staring at the national brand on the top of his head, and the directly subordinate to the Central Machinery Department, Yun Fei, who is not even a worker now, how can he argue with such a giant?

"Align the hole in the middle of the gear with the shaft, there is only less than a trace of clearance, if it is crooked, it will not fit in. This is not an assembly of ordinary lathes, there is nothing wrong with a crooked one, and when the time comes, just knock it in with a copper rod...... "As the boss, Yun Fei, when Yang Bingbiao, the workshop director of the assembly workshop, personally went to the assembly of the first CNC machine tool in his factory, he, a young boss who knew more about CNC machine tools than any of them, was in the middle of the dispatch and command.

"Xiaoyun, except for the inverter installed on the spindle, this is no different from an ordinary lathe, right?" When they first saw the assembly drawings, Yang Bingbiao and the others were full of doubts, but Yun Fei didn't explain it to them, so they could only hold it in their hearts.

Now that the spindle of the lathe has been installed, it is found that the first CNC lathe produced by Jiuyi Heavy Industry, the gears in the headstock are no different from other 6140 lathes! The only difference is that a fist-sized inverter is installed at the end of the spindle of this lathe, which is said to be used to control the rotational speed of this lathe.

This made Yang Bingbiao and those senior assemblers from the Soviet Union puzzled, since the inverter used to control the speed of the spindle was installed, why should so many gear sets be installed? What kind of manual fork is still used to control the speed of the lathe?

"The inside of the headstock is actually the structure of an ordinary lathe!" Yun Fei's indifferent words made everyone who had been carefully assembled depressed.

"Although it is the headstock of an ordinary lathe, there are still some subtle differences. You are all masters, haven't you noticed that according to the current way, the speed of the machine tool can be changed manually, and it can also be continuously changed in the gear. Although there are more than 20 kinds of speed changes on ordinary lathes, the difference between the two speeds is not too big, especially in high-speed gears, the difference between each gear is at least hundreds of speeds, and many materials with high requirements for linear speed are processed, and the speed of ordinary lathes cannot reach the most reasonable ......," Yun Fei explained to everyone.

At the beginning of the design, the Soviet engineers thought that Yun Fei, the layman boss, was blindly directing, since he could get the inverter, he could manufacture a CNC lathe that could carry out three gears in high, medium and low gears, and infinitely variable speed in the gear. However, when the mathematical model was established for analysis, it was found that the CNC machine tool with infinitely variable speed in the three gears was not a little bit worse than the CNC lathe with the infinitely variable speed in more than 20 gears, although there was no difference in the speed, but the poor rigidity was not a little bit.

After the gears in the headstock are installed, there are only ball screws and stepper motors that control the displacement of the machine tool, and the control appliances of the machine tool.

Whether there is any problem in the assembly can only be found in the process of trial processing. The machining accuracy of the machine tool needs to be reflected in the machining result only when the parts used for processing are completed.

Most of the circuit design of this CNC machine tool is completed by Yun Fei himself, and the final assembly is completed when the electrician connects the independent PLC controller of the machine tool to the electrical box of the machine tool.

As early as when Jiuyi Heavy Industry just started production, Yunfei mobilized 20 sets of CNC systems for lathes from Huadu CNC, as well as the most critical CNC machine tool accessories such as ball screws and stepper motors to Rongcheng. He would like to use a servo motor, but the servo motor is not only difficult to use, but it is also too expensive. A servo motor costs thousands of dollars!

Now this CNC lathe, which carries the dreams of all the people in the workshops of the entire Jiuyi Heavy Industry, has finally completed the most difficult assembly. (To be continued......)