Chapter 63

Under Li Lu's dissatisfaction, the food quickly came to the table.

Zhao Xingbang was intrigued by Yunfei's words and had no appetite for the full table. He just hoped that Li Lu, Ren Zhiguo and Yunfei, who were wolfing down, would finish the luxurious lunch quickly and find a place to talk for three or five days.

Zhao Xingbang also knows Li Lu best. In addition, this place is not suitable for a few people to talk about this. So after the meal, no one talked about this topic again.

Originally, Ren Zhiguo wanted to drink with Yun Fei, but when he asked the waiter to serve wine, he was stopped by Zhao Xingbang. Ren Zhiguo had to give up the idea depressed. In front of Zhao Xingbang, a stern old man, he really didn't dare to be presumptuous.

The dinner without drinking was soon over. Li Lu pleaded guilty with some old men of Zhao Xingbang, said he had an appointment with his friends to go shopping and ran away. Ren Zhiguo also wanted to slip away, but he was left behind.

The waiter took several people to the private room of the teahouse on the fifth floor to make tea for them, and Zhao Xingbang drove them out.

"Xiao Yun, how about talking to us in detail now?" Zhao Xingbang had lost his composure as a superior. As soon as he kicked out the waiter, he said hurriedly.

"Uncle Zhao, don't you doubt that this hairy child is bragging now?" For Zhao Xingbang's performance, Ren Zhiguo, who has always been excited about the old man who came out of the dead, was excited. From small to large, no matter what happens, he can take it lightly. The old guy who was beaten as a villain and locked into the cowshed did not change his face at all. He was as impatient as a whore when he saw the famous prostitute of Chaosi's dream. How can he not feel like turning over!

"Go, go, go, stay and drink tea while adults talk. Don't interrupt your children..." Zhao Xingbang stared at Yun Fei anxiously and waved to Ren Zhiguo.

"..." Ren Zhiguo was speechless, and Yun Fei was also speechless. Once upon a time, Lao Ren, who was more than ten years older than himself, became a child, and his child in everyone's eyes became an adult?

"Director Zhao, for the parts you need to process, I just looked at them roughly at that time. I mentioned with Lao Ren that the processing of those parts may not meet the requirements." Yun Fei was a little embarrassed about the eagerness of the old man in front of him. At this time, the fear of the old man was gone.

In order to deceive Ren Zhiguo, a guy who didn't know anything about CNC machine tools, he said everything very simply. After thinking for so long, I found that the scheme I proposed could be processed to that accuracy in theory. In fact, it could not be guaranteed at all.

The difference between theory and practice is caused by many hardware conditions. For example, the accuracy of stepping motor and ball screw determines the control accuracy of NC device. Domestic lead screws may be able to achieve, but for four-axis linkage machine tools, stepping motors are difficult to control the linkage of four axes, and there is no way to ensure the accuracy.

Therefore, the four axis machining center must be controlled by the servo motor. The servo motor must have position detection device and pulse transmitting device. The delay of the feed pulse signal, the precision of the position detection device, the error of the feedback pulse and so on are the first stage and insurmountable mountains.

"What?" Maji didn't believe that Yunfei, such a child, could know more than those who have been engaged in CNC machine tools for more than ten years. However, seeing that his superior didn't say anything and knew his superior's mind, he could only vaguely express his dissatisfaction.

"I think this is too simple. Since Lao Ren left, I have been thinking about how to add PMC axis module on the three axes to implement the fourth axis function. What can be obtained in China is basically the stepper motor. The indexing control of the stepper motor on the rotary worktable depends on the accuracy of the stepper motor itself, which affects the indexing accuracy of the worktable in the processing process... "Yun Fei stopped to wait for the digestion of several people when he saw the blankness on their faces.

"Xiao Yun, according to your meaning, wouldn't it be better for the stepping motor to be directly connected to the transmission of the rotary table?" A middle-aged man in his 40s and 70s with glasses asked suspiciously. For CNC machine tools, although no breakthrough has been made, the engineers brought by Zhao Xingbang are still familiar with the understanding of these basic technologies.

"Who is this?" Before dinner, Ren Zhiguo only introduced several people brought by Zhao Xingbang as an assistant. Yun Fei really couldn't help calling them.

"My name is Zhang Jun, who is in charge of transmission..." Zhang Jun doesn't care that Yun Fei doesn't know his name at all. Let alone that Ren Zhiguo deliberately didn't introduce him at the beginning. Even if he did, Yun Fei can only blame himself for his lack of ability. After all, I've studied this for more than ten years. I'm not as good as a young man

"The operation of stepping motor is controlled by pulse signal. The frequency of pulse signal controls the speed of rotation, and the number of pulse signal controls the rotation angle of motor. It is not impossible to control the rotation accuracy of the fourth axis by controlling the pulse signal, but it requires an industrial control chip with powerful control function. The industrial control chip needs to be able to control not only the operation of the fourth axis, but also the linkage between the other three axes and the fourth axis. " Yun Fei explained.

"Industrial control chip..." Zhao Xingbang, Ma Ji and Zhang Jun sighed at the same time. A lost face.

"You should be clear about the distribution of CNC machine tools according to the control mode?" Yun Fei felt the same pain for the sigh of several people. Changed the subject.

"Well, we really don't know." Zhao Xingbang blushed a little about Yun Fei's problem.

For a long time, they have studied stepping motor controlled machine tools. After all, this is simple. Servo motor, they know that foreign high-precision machine tools and large heavy CNC machine tools have begun to eliminate the use of stepping motor. However, the domestic foundation is too weak. They don't even understand the stepping motor. How can they disperse their energy to develop high-precision CNC machine tools controlled by servo motor!

At present, many research institutes and machine tool companies in China are engaged in research in this field, but after so many years, we haven't heard who has made a breakthrough.

"According to the control mode, the CNC machine tool control system is divided into open-loop, closed-loop and semi closed-loop. Except that the drive and control of the open-loop system are realized by stepping motor, the other two need servo motor to control. Although the actuator of the open-loop system is controlled by power stepping motor or electro-hydraulic servo motor. The control accuracy directly depends on the accuracy of the motor and screw rod. However, due to the lack of position detection device, although the work is stable and easy to master, the improvement of accuracy and speed are limited. " Yun Fei began to literacy a group of people who have studied CNC machine tools for more than ten years.

These most basic things can be clearly answered by even a technical secondary school student majoring in numerical control in 20 years.

"Closed loop control system, which is equipped with position detection device on the moving parts of the machine tool. Not only high precision, but also fast speed. As for the semi closed-loop control, it is to install the position detection device at the end of the transmission screw rod and indirectly measure the position of the executive parts, which is not only convenient for debugging, but also has good stability. It is mainly used for... "Yun Fei is like a theory teacher in a technical school, talking to several people about these most basic things.

After explaining the basics of literacy, Ren Zhiguo had curled up on the rattan chair and fell asleep with saliva. Several older students are taking notes quickly.

"Well, Xiao Yun, let's talk about the four axes now?" Zhao Xingbang has completely lost that bullying momentum now. He asks Yun Fei pitifully.

He has completely believed what Ren Zhiguo told him. As for whether it can be done, it is only a matter of time.

Another biggest problem is the identity of Yunfei. The better Yunfei performs, the more frustrated Zhao Xingbang is. After all, the research on CNC machine tools is still in the stage of confidentiality in China. Although the things studied are very low in the eyes of this young man, we can't just put Yunfei in front of him or bring Yunfei to the Research Institute.

In China, since the Mechanical Department of Huaqing University joined hands with the capital No. 1 machine tool factory to engage in CNC machine tools in 58, many enterprises have sprung up a trend of CNC machine tools, but they are stillborn due to various problems. In addition, the great turmoil in the following decade made many talents who studied this field lose news.

What Yun Fei knows, Zhao Xingbang dares to doubt that there will definitely be a powerful folk research team behind this guy. Their progress has exceeded that of most people.

But is that possible?

Thinking of Yun Fei's young age, he not only has the ordinary machine tool operation technology that makes those teachers marvel, but also is especially good at the processing of NC machine tools. Under the banner of foreign trade processing, camart has put many high-precision parts into camart's company for processing. It is said that it was all done by Yun Fei, a young man.

"Xiao Yun, if we provide full support, how long do you think it will take to get the added fourth axis?" Zhao Xingbang didn't take notes. His responsibilities and not only technology, but also the urgent demand for four-axis machining center. Now he has to avoid the identity of Yun Fei for the time being.

"If there are enough technicians, materials can be guaranteed and the capital chain continues, there should be no problem in three years." For the unidentified military person in front of him, Yun Fei didn't dare to say too much.

"Three years... How much money will it take?" Although it takes a long time, he can still afford to wait. The question of how much money is needed now is what Zhao Xingbang is most concerned about. All domestic priorities are inclined towards economic construction. It is well known that the military is in short of military spending. If too much research funds are needed, they can only be shelved.

"At least seven or eight million..." Yun Fei's words made everyone take a breath.

Seven or eight million, all the research on CNC machine tools in China add up. I don't know if there can be such a number.

"Xiao Yun, you shouldn't be the director of a CNC Machine Tool Research Institute?" Zhao Xingbang's heart sank to the bottom of the valley. For Yun Fei, such an excellent talent, especially his understanding of CNC machine tools, he doesn't want to give up. He first pulls people to the Research Institute, and then does it slowly. One day he will do it. So he said something that shocked everyone.