"We used an eccentric multi-axis cutterhead design method in which the cutters were eccentrically supported at the front ends of multiple drive shafts, so that when the drive shafts were rotated in the same direction, the cutter holder could move in parallel rings to create a tunnel section similar to the shape of the cutter.

With this design, it is possible to excavate various sections such as rectangular, oval, horseshoe, and circle as long as the frame shape of the cutter is changed, and it has excellent adaptability......"

In the large lecture hall of the National Convention Center, a report entitled "Technical Seminar on Domestic Shield Machine" is underway. On the podium at the front of the lecture hall, it was Feng Lingyu, chief engineer of the shield machine project of Chenyu Construction Machinery Company, who pointed to the graphics on the big screen with a laser pointer and talked eloquently.

In front of Feng Xiaochen, Feng Lingyu will always be a little childish, even lazy, but standing on this podium, facing a group of colleagues and many reporters, Feng Lingyu is full of vitality, with a strong self-confidence between his eyebrows, showing the true character of a returnee elite.

"Chief Engineer Feng, an important difference between the non-circular shield and the circular shield is the difference in the control axis, the non-circular shield has different deviation correction moments in all directions, how do you solve this problem?" an expert from the China Railway Research Institute raised his hand and asked.

Feng Lingyu switched a slide and pointed to the screen to introduce: "Regarding this problem, we have adopted a reconfigurable zonal propulsion system, the whole system consists of 32 cylinders, divided into 6 to 8 zones according to needs, and the thrust of each zone can be adjusted individually. The propulsion jack can be grouped on the operation panel of the control room, and the grouping can be adjusted and reconstructed at any time according to the construction needs. ”

"Chief Engineer Feng, how did you design your double cutterhead structure?" another expert asked.

"We have an X-shaped body design, and when the cutterhead rotates, the notches at both ends of the X-shaped shape provide space for another cutterhead to pass through......"

"I noticed that your cutterhead drive is driven by a motor, while a hydraulic motor is generally used abroad, what is the reason for your design?"

"The advantages of motor drives are low noise and high efficiency, but the disadvantages are that they are large and output less torque for the same amount. With the increase of shield diameter and system power, the fuel tank and pumping station corresponding to the hydraulic motor are getting larger and larger, and the structure is becoming more and more complex, which will greatly increase the difficulty of maintenance for the construction unit. Weighing the two phases, we believe that in large diameter shields, it is more appropriate to use a motor drive. ”

“……”

The seminar was jointly organized by the State Equipment Industry Corporation and Chenyu Construction Machinery Company. Needless to say, the face of the equipment company, Chen Yu Construction Machinery Company is already well-known in China, and major universities, scientific research institutes and construction machinery counterparts have close contacts. The two came forward at the same time, and invited all the big names in the field of construction machinery in China, and the weight of this report should not be underestimated.

When the experts were invited to participate in the meeting, they had some cheering mentality, and after listening to the design ideas introduced by Feng Lingyu, everyone's emotions were mobilized. In recent years, the number of domestic tunnel projects has increased dramatically, the application scope of the shield machine has been expanding, and there are more than a dozen units that are developing the shield machine, and relevant experts from universities and research institutes are often invited to participate in the design.

In the process of development, everyone has encountered various difficulties, some of which have been solved through hard work, and some are still in the process of exploration. Chen Yu company is the first to complete all the design of the enterprise, their design ideas and breakthroughs in some key technologies, for everyone is very inspiring.

The reporters sitting in the back were busy taking photos, others struggling with keyboards on their laptops. The reporters could only listen to the discussion of the technical experts in the past, and they couldn't even write some words. But it didn't matter, they were tasked with promoting the symposium vigorously, and some of the key content organizers had already written a press release, and they just had to extract what was useful to them and fill in the report.

Feng Xiaochen has always attached great importance to publicity, and he knows that in this era, the media can make things or fail, it all depends on whether you have mastered the media. The responsibilities of the equipment company are heavy, but the power in his hands is very limited, Feng Xiaochen can use the benefits brought by the development of equipment, the second is his contacts in the field of equipment, and the third is the power of public opinion.

Because of this, there is a special public relations and publicity department within the equipment company, which is responsible for contacting various media, and will send some benefits to relevant reporters during the New Year's holidays, and can often provide them with some important news clues, so that they can run faster than other peers. The reporters reciprocated, and when the equipment company needed their help to build momentum, they had nothing to say.

"Chief Engineer Feng, I have a question I would like to ask. When it came to the media's questioning session, a reporter stood up, lifted his glasses, and asked with a serious appearance: "I am an industrial newsman, and I also know something about shield machines." Just now, Chief Engineer Feng introduced in the PPT that the rated jacking force of your shield machine jacking control system is 75,000 kN, and I heard that this index of Prometheus is 81,000 kN, may I ask, does this mean that the performance of your shield machine is not as good as Prometheus?"

The reporters sitting next to him grinned into a rectangle, Nima, everyone has been a childcare, please can you be more professional. What is the rated top force or something, it flashed on the slide, and you actually saw it, and said that you had heard of what the level of Prometheus was 81,000 kN. Everyone graduated from the Department of Journalism, did you say in your school's professional class what is called Qianniu?

Thinking so, you won't miss this question at all. Since the organizers have carefully arranged childcare, it is natural that this issue is very important, and in future reports, even if today's weather is written wrong, this problem must not be ignored.

"On this issue, let me explain it for Chief Engineer Feng. An expert from the Railway Design Institute stood up, and the staff who were serving in the audience hurriedly handed him a wireless microphone. The expert fed him twice, tried the microphone, and then began to tell: "We have done tests on the issue of the rated jacking force of the jacking control system......

Then, he reported a long list of test data, which made people dizzy to hear, and finally knew only one conclusion, that is, there is no essential difference between 75,000 kN and 81,000 kN, and there is no need to dwell on this issue.

The background information of the experts was also projected on the big screen at the front end in a timely manner, and the long list of titles, what special allowances, what Changjiang Scholars, what outstanding contributions, and what national first prizes were even more dizzying than the data that the experts just said. Of course, you don't need to memorize these contents, you just need to remember that he is the top cattle in China, and his words are the truth, at least in the field of tunnel engineering.

"Chief Engineer Feng, I also have a question......

After answering the previous question, another reporter stood up, also a tricky and strange question. If the people of the river railway company were present, they would find that this problem happened to be one of the conditions for the equipment bidding of the river railway company in the Huoyuan subway project, and the shield machine of Chen Yu company happened to be stuck in this condition.

"I'll also answer this question for Chief Engineer Feng...... "An expert from the Institute of Automation of the Ministry of Industry and Information Technology stood up, this question is about automatic control systems, and he is an authority in this field.

These reporters and experts who volunteered to come out to endorse are naturally the nurseries found by the equipment company and Chenyu Company, and this question and answer are all prepared. In particular, the experts' answers are absolutely justified and can be used as evidence for the lawsuit and brought to the table for more seriousness.

When the equipment company and Chenyu company came to ask the experts to be nurses, these experts were happy to accept. Everyone is engaged in shield machines, who doesn't want domestic shield machines to be quickly applied. Chenyu's shield machine has been recognized, representing not only Chenyu company, but also all domestic brands. The strength and reputation of some domestic state-owned construction machinery companies are far greater than that of Chenyu company, if the products of Chenyu company are reliable, domestic users have no reason not to believe in the products of these large state-owned enterprises.

The actions of the river railway company can be regarded as an unspoken rule in the industry, and there are countless manufacturing companies that have been hurt by this unspoken rule. I heard that the purpose of this seminar is to challenge the unspoken rules of the industry, to support domestic equipment, experts can almost no appearance fee, bring their own dry food to the platform of Chen Yu company.

"Hey, Lao Wang, what do you mean by that question just now?"

"This matter, haven't you heard about the bidding for Huoyuan subway engineering equipment?"

"Huoyuan Metro, what is that, can you eat it?"

"You don't even know about the Huoyuan subway, Huoyuan City, Heyang Province, is now preparing to repair the subway, let me tell you......"

"Oh, that's what happened, hold the grass, I said......"

"I've annoyed the equipment company, hehe, there's a good show to watch......"

Offstage, reporters began to exchange insider information with each other. When the equipment company invited reporters to come, some of the words were not said very thoroughly, which also meant that they did not want to give people a handle. The public relations department of the equipment company knows that the reporters have an extremely sensitive sense of smell, and as long as they are given a clue about some things, they will naturally figure out the cause and effect.

Of course, there are also some news that equipment companies do not want to spread, and it is inevitable that it will circulate:

"By the way, do you know that this Chief Engineer Feng is the younger brother of President Feng of the equipment company?"

"The cake seller, such a fierce material, who did you listen to?"

"Hey, Feng Xiaochen, Feng Lingyu, have you noticed that the name of Chenyu's company has not ......?"

"I don't know, I haven't noticed, don't talk nonsense ha......"