Chapter 189

Generally, the accuracy grade of ordinary lathe guide rail is only grade 5, and the surface roughness is 0.8. Flatness and straightness are relatively large compared with precision machine tools.

Taking an ordinary machine tool as an example, the general accuracy range is: for an ordinary lathe with a processing length of one meter and a rotation diameter of 400 mm, the roughness on the guide rail surface must be more than 0.8, the straightness shall not exceed 0.015mm and the flatness shall not exceed 0.012mm.

The longer the guide rail, the greater these tolerances.

Of course, for the same type of machine tools, the smaller these values are, the higher the accuracy level they represent. Similarly, the more difficult it is to achieve the accuracy.

On the earth, the country that produces the highest precision ordinary machine tools is not Germany with the best technology or the United States with the strongest strength, but Switzerland, a small European country! Of course, the ordinary machine tool with the highest production accuracy here does not mean the highest technical level that the whole country can achieve, but the overall manufacturing level.

Yun Fei doesn't know whether the specific facts are like this. Anyway, the actual situation he once realized is like this.

Switzerland is only a small country in Europe, and its domestic industrial foundation is not perfect. However, the production capacity of ordinary machine tools produced in China far exceeds that of his, which is almost in short supply. The price of an ordinary lathe made in Switzerland is three times that of the lathe with the highest precision grade made in China!

Let alone CNC machine tools.

Excluding the most sophisticated high-end CNC machine tools that European and American countries are unwilling to sell to China, but Japan is afraid to sell to China. In China's high-end CNC machine tool market, the first choice for domestic users is also the CNC machine tools made in Switzerland. Switzerland's CNC machine tools even surpass Germany in terms of machining accuracy and stability! However, he has no German production capacity, so there is no way to compare with Germany in quantity.

Yun Fei once saw a precision ordinary lathe imported from Switzerland in the 1980s. After nearly 20 years of use, it can even produce two or three μ Precision parts!

Domestic ordinary lathes, small ordinary lathes, conventional lathes with rotation diameters of 250mm, 320mm and 360mm, the maximum speed is only 2000 revolutions, but those made in Switzerland can reach more than 3000 revolutions!

People who do machining know that the smaller the diameter of the processed part, the higher the linear speed required. Because the smaller the diameter of the rotating body, the smaller the linear velocity when rotating. Even if it reaches 10000 revolutions, the linear velocity of the rotation center of the workpiece is zero. However, the farther away your center point is, the higher the speed and the higher the linear speed under the same diameter.

Although the highest speed of domestic ordinary lathe is 2000 rpm or 1800 rpm, it can't be used at all. Because that speed is only the design speed of the machine tool. If such speed is really used, the parts will be processed for a long time. Before long, all the gears in the whole spindle box will be scrapped. But the Swiss would not have this problem.

The reason why Yunfei wants to establish a one-level or half-level standard higher than that of his domestic counterparts on his own machine tools is that he is too impressed by Swiss cutting machine tools.

The smoother the machine tool guide rail is, the more stable the cutting process is. In this way, the product quality will naturally be higher.

How can the accuracy level of a machine tool be reflected? It depends on the quality and accuracy of the parts processed by this machine tool! Machine tool users do not have the professional testing equipment of machine tool manufacturers. Therefore, they test the accuracy of the machine tool, which is very simple, that is, directly install a part on the machine tool for one-time processing.

"Director Yun, you'd better not stare here, or you can go back to your office for tea, or read the newspaper and wait. How about I call you?" Yang bingbiao tried several times with the special file in his hand, but he couldn't find the feel at all. It was the same with goodrian when he turned his head. He didn't have the state when he first came to China and repaired the guide rails of those large equipment with himself in the mountains.

"It's all right. You fuck you. I'll watch next to you. It won't affect you." Yun Fei has always been curious about how the Ninth level fitter grinds out the guide rail by hand, especially the detection means of the Ninth level fitter.

It turned out that Yang bingbiao had no time to see them when they repaired and maintained these equipment in the cave in the mountain and overhauled the machine tool. In the original world, the overhaul of machine tools and the grinding of guide rails were all done by guide rail grinder. He can't see it at all.

If the accuracy of the machine tools in their factory drops sharply, they will not be overhauled at all. Instead, they will be sold as scrap iron to second-hand equipment and buy new equipment instead. State owned enterprises are short of everything, but they are not short of money. Many of the state's annual financial allocations can't be spent for good reasons. The purchase of equipment is absolutely a justifiable reason.

Yun Fei always wanted to see the nine level fitter grinding guide rails in this era. He knew that in a few years, there would be almost no scene of manual grinding guide rails in China. The reason is that China's most elite mechanical workers have retired, and the newly growing skilled workers have no chance to contact the ultimate cause of fitter. In addition, the efficiency of manual grinding guide rail is too low. If a person comes to grind a guide rail and a guide rail, it will take at least ten days and a half months!

"We won't work if you are here..." Yang bingbiao told the truth directly, regardless of the boss in front of him.

When Yang bingbiao said this, goodrian nodded his head.

When the boss Yun Fei began to guard the previous processes, he roared for a long time in each machining process, but the whole factory heard it.

When grinding the guide rail, the energy can be highly concentrated, otherwise the guide rail repaired with a file will be uneven. In the martial arts world, the master pays attention to the integration of one person's sword and the nine level fitter grinding the guide rail. Just like those super masters in the martial arts world, they have to integrate one person's sword when competing with others. Otherwise, they will not be able to reach their highest level and turn over the enemy.

The existence of Yunfei makes both Yang bingbiao and goodrian unable to be quiet, because Yunfei always keeps asking all kinds of questions.

"Er..." for Yang bingbiao's words, Yun Fei was speechless.

He understood what Yang bingbiao meant.

He asked questions here, such as whether the guide rail with secondary precision can be ground, and how to make more people reach their level, which put pressure on the master who can represent the highest level of Chinese and Soviet skilled workers in the whole factory.

It's too difficult to reach the accuracy level beyond level 4.

Yunfei is like this. He just wants to learn from Switzerland. Because the guide rails of precision machine tools in Switzerland can be repaired little by little by workers with files and oilstones! The residual internal stress of the machine tool produced in that way in the machine tool bed structure is very small, which will not affect the most important track of the machine tool bed with reasonable design. Some people are even bored and use mathematical models to analyze machine tools produced in Switzerland. If they are not oxidized by oxygen in the air, the machine tool guide rail will not produce deformation of more than 0.02mm even after 100 years.

"Brother Yunfei, what's the matter with you?" Ni Lishuang is now a clerk in Yunfei's office, and Yunfei's assistant is still the fourth girl of the Mao family.

Ni Lishuang's main position is in finance, but she only graduated from a technical school. In addition, she has no practical experience in finance, so she works as a clerk in Yunfei's office and follows the finance department.

She is Yunfei's housekeeper. She must help Yunfei manage the money so that her children and Yunfei won't starve in the future!

"What can he have? Want to go to the production workshop to see master Yang grinding the guide rail... "Mao Yadong was very unhappy about this. The sisters who grew up together poured out the reason why Yun Fei was restless.

"What's good about grinding guide rail? It's just that several teachers know how to scrape oil with a file... "Ni Lishuang really doesn't understand this.

Although she doesn't understand machining, she watched her brother Yunfei learn those things from childhood. She doesn't think there can be much technical content in a job that doesn't even use equipment.

And classification won't tell them. Maybe we won't see such a scene again soon.

I've experienced it for two lifetimes, and I can't see that the processing level can be far higher than that of the most sophisticated advanced machine tools just by people and some simple tools.

After three days of restlessness, Yun Fei felt unable to wait less than half an hour after working on the fourth day. He wanted to go to the scene, but he was worried that it would affect their work. He was going to take the two women in the office to the ball screw factory guarded by Wang Qingfeng to see the processing center just delivered, and was told that the guide rail had been polished.

Although I didn't see how the level 9 fitter detected and processed the process, Yun Fei was also very happy to see the results obtained in the processing process.

"Did you stay up all night last night?" When Yun Fei came to the scene, he found that not only Yang bingbiao and goodrian, but also several other level 9 fitters in the whole factory were here. All of them were red eyed and tired.

"I know you are anxious to see the finished product. After scraping, I left the other brothers at 6 o'clock yesterday afternoon. I began to grind the surface of the machine tool with oilstone and sandpaper in turn. Now it has barely reached the third level of accuracy..." Yang bingbiao replied Yun Fei with a tired face.

"I'll go..." Yun Fei secretly vomited a long breath!