Chapter 187

For these high-precision ball screws, the maintenance of production technology for precision is even much higher than that of high-precision production equipment.

Yun Fei believes that the production technology used by countless manufacturers in the world will not ensure the accuracy of the ball screw.

"The most important problem in the production of ball screw is not just the material. But now all we can control is the arrangement of production process. I think production technology is also very important in your Soviet Union? Especially in these highly precise parts. Of course, for you, I don't ask you to produce Chinese national standard zero precision ball screw, but you must at least produce three-level ball screw for me! Otherwise, how can you afford your annual salary of 12000? "

The work of the ball screw factory is not very heavy, but we must put some pressure on the proud mechanical engineer from the Soviet Union.

For the current production, Yunfei's requirements are not so high. As long as the factory can produce ball screws that barely reach level 5 accuracy, it can meet the use of CNC machine tools produced by 91 heavy industry. After all, in China, the largest market is not high-precision CNC machine tools, but a large number of simple CNC machine tools.

In the production range of simple CNC machine tools, the minimum tolerance is generally more than one thread eight. Most of the mass-produced parts have a production progress of more than four or five threads, or even more than ten threads. It is not cost-effective to use high-precision machine tools to produce these parts with not too high requirements. Not only the wear of machine tools is relatively large, but also the service life and processing level of machine tools are reduced. More importantly, the price of precision CNC machine tools is several times or even ten times that of simple CNC machine tools.

In Yunfei's world, there are millions of CNC machine tools in the whole country, of which more than 90% are the lowest simple CNC machine tools. At the same time, the sum of the value of 90% of the lowest simple CNC machine tools can only be compared with the value of 10% of medium and high-end CNC machine tools.

In other countries, especially the United States, which has the largest number of CNC machine tools, the number ratio of high, middle and low-grade CNC machine tools is about 1.5 to 3 to 5.5. Although Germany and Japan have CNC machine tool technology today, the number is far less than that of the United States, but the ratio of digital machine tools in various gears in their country is far higher than that of the United States.

Therefore, if you want to produce CNC machine tools in China, Yunfei will never give up in the medium and high-end market. You have to bite the fat meat if you work hard. On the surface, Yunfei will not give up the low-end CNC machine tools whose value is not very high.

Now, when he is poor and has no foundation at all, Yun Fei can't help but expect to produce medium-grade or even high-grade CNC machine tools with the help of many CNC machine tools he has seen in future generations, as well as some theoretical knowledge he has operated many CNC machine tools and fooled around with Du Niang.

If it's really that easy, it won't be that when he leaves his world, Huaxia hasn't produced high-end CNC machine tools in the real sense. China's real domestic enterprises can't even produce five axis machining centers!

Since the current goal is the largest low-end CNC machine tool market in China, the low-end simple CNC machine tools with millions of users will be a great waste if they use ball screws with accuracy above level 3.

Although the production process of non arranged ball screw is more complex than the current one, it is easier to ensure the machining accuracy. The ball screw production process designed by Yun Fei is several more than that in his own world.

He knew that although the production process above Du Niang could be processed, it could not reach a high precision level at all.

Therefore, he added forging, rough turning, quenching and tempering, lathe finishing, and then carried out the arc spiral groove on the cold-rolled ball screw. After high-frequency quenching, he arranged a lathe finishing before the final grinding process.

This production process is not the cold-rolled ball screw used in China (often referred to as "rolling screw" in Europe and America). It is mostly made by batch conversion and rolling, and then made into ball screws of different lengths according to needs. The pressing process of ball screw thread is mostly the same at home and abroad, and the processing process of single cold-rolled ball screw in the later stage is slightly different.

Most of Europe and America adopt shaft end hard turning process, which has simple process and high efficiency; At present, China is still mostly the traditional process of turning bearing pedestal after shaft end annealing. Compared with foreign countries, the domestic production process is self-evident in terms of use effect and production cost. The machining process of quenched steel ball screw with large allowance is more flexible and convenient for overall production arrangement, replacing annealing process and secondary quenching process; In addition to the exquisite appearance of the processed products, the shaft end also reduces the unstable performance defects of the ball screw caused by multiple heat treatments.

Yun Fei is the on-site technician in the production workshop. He knows more about how to reasonably use the existing equipment to achieve the highest production efficiency and precision than those who have only worked with theoretical books in the office for a lifetime.

He wants to adopt the hard turning process often used in Europe and America, but the current domestic tools simply can not achieve mass rough machining of Rockwell hardness reaching HRC58-62. The production cost of using ceramic blades imported from abroad is too high. Similarly, the hardest diamond blades can only be used for precision machining, but can not be used for rough machining at all. Otherwise, the cost of blades alone will cost the four million invested by the two people nothing!

Therefore, in the current situation, Yunfei can only use more complex processing technology to produce ball screw with low precision.

In any case, the cost of forging and heat treatment of Jiuyi heavy industry is his, but he put the money of him and Wang Qingfeng in his own pocket. Wang Qingfeng has nothing to say about this.

At the beginning, if Yunfei didn't want to play with him, there would definitely be a production workshop specializing in the production of ball screws in the huge factory of Jiuyi heavy industry. If so, Wang Qingfeng could only look at Yunfei sadly. He spent a fifth of his factory to buy a personal Yunfei every day.

The production process, especially the ball screw, which he had not touched before Yunfei said it, was very strange. The materials chosen by the Soviets and the precision of the designed production process could not be achieved. After being changed by Yunfei, it was achieved in a very short time!

Wang Qingfeng sees the market prospect of ball screw now. Especially now in the domestic CNC machine tool industry, after the emergence of Huadu CNC dragon system, a large number of foreign key accessories are exported to China. What a profit! You know, ball screw is not another product. It is an essential key part of CNC machine tool!

Ball screw is sold in China by rice!

By calculation, the material cost of a ball screw with a diameter of 50 mm and a length of two meters is only three or four hundred yuan, plus various costs such as heat treatment, processing fee and factory management fee, it is only about 1000 yuan, but it costs at least four or five thousand yuan to buy it in the market!

According to China's ordinary machine tool market, even if China produces 50000 CNC machine tools every year, if half of the factories buy ball screws from his and Yunfei's factories, Wang Qingfeng faints happily at the thought of this data.

Moreover, a CNC machine tool can use more than one roller screw! Although the lengths and specifications are different, in China in this era, the ball screw is sold for 3000 yuan a meter, and someone will definitely rush to buy it.

The grinding machine, which was bought from the second-hand market in West Germany, is more efficient after being improved by the old maozi of 91 heavy industry; The production of ball nut is much simpler than that of ball screw.

For the connection between ball screw and ball nut, Yunfei adopts the circulating elbow type designed by sevianvsky. Yun Fei didn't know what this connection was like at first, but when the ball screw, ball nut and ball were produced, he found that it was the most widely used connection in his world.

The so-called circulating elbow connection is that after the ball is returned to the loop process, it returns between the screw rod and the nut through the circulating groove outside the nut to re-enter the loop. This connection form has the advantages of simple structure, good manufacturability and high bearing capacity. The only bad thing is that the radial size of the nut is large. After all, there must be two layers of spiral grooves on the nut, which is used for the roller to continuously cycle between the nut and the screw rod. However, this disadvantage can hardly be called a disadvantage for the current Chinese CNC machine tool market!

Of course, if you want to buy a ball screw on the market, you have to sell not only a single ball screw with high precision circular arc spiral groove, but also ball nuts and balls matched with the ball screw.

These things, combined together, form a ball screw pair.

Chengdu xinkaixing ball screw factory sells ball screw pairs.

With Yunfei, a man from later generations, the test of a ball screw in Chengdu xinkaixing factory was very smooth. In a short period of more than ten days, a sample was produced after changing the production materials and changing the production process.

Although this test meets the design requirements in all aspects, whether it can use the market demand will not be known until Yunfei's Jiuyi heavy industry produces the first CNC lathe and uses it for a period of time. Therefore, now the main energy of Chengdu xinkaixing has been invested in the business of NC machining again.

If Jiuyi heavy industry can produce CNC lathes, the whole Chengdu xinkaixing ball screw factory will have a great development. Similarly, if this ball screw can ensure the stability of quality, the CNC machine tools of 91 heavy industry will definitely quickly occupy the domestic market of international machine tools assembled with imported ball screws with low accuracy.

Everything is waiting for the first CNC machine tool of 91 heavy industry to go offline!