Interpretation of the whole process of construction electromechanical engineering process interpenetration
On July 2, 2017, the long march No.5 yao-2 rocket was launched at Wenchang space launch site in Hainan, but the rocket broke down suddenly when it flew to 346 seconds. After layer by layer elimination, the failure reason is determined as that the turbine exhaust device of the first unit of the core level liquid hydrogen liquid oxygen engine has abnormal local structure in the complex thermal and mechanical environment, and the thrust of the engine drops sharply and instantaneously, resulting in the failure of the launch mission.
The design drawing of the turbine exhaust device has been changed, and five guide vanes have been added on the basis of the original parts. The substantial modification of the design drawing means that all existing parts in stock are scrapped. It is urgent to produce new parts, and the difficulty of machining is increasing because the materials of parts need to be changed from stainless steel to nickel base superalloy.
The responsible unit attaches great importance to this improvement. All the workshops with rocket turbine exhaust parts are gathered for a meeting. Everyone thinks that time is tight, if we use traditional mechanical milling to produce parts, it will delay the development of China's aerospace industry, and the cost is very high, it will cause significant economic losses.
After nearly a year of "dormancy" after the successful development, the high-end equipment manufacturing technology innovation team of China University of Petroleum (East China) School of mechanical and electrical engineering has developed the EDM arc composite high-speed digital milling technology and its numerical control machine tool, which has a place in use.
Liu Yonghong, head of the team and Dean of the school of mechanical and electrical engineering, once thought that this major breakthrough, which had been developed in the laboratory for more than 10 years, would have a chance to be used in China's aerospace industry, but he did not expect that the opportunity would come so fast. Compared with the traditional method, the graphite tube with several yuan replaced hundreds of thousands of mechanical tools, which greatly saved the cost, and the efficiency was dozens of times of the original. After breaking through a series of problems, the processing time was shortened from 24 hours to less than 8 hours. Finally, with the help of this technology, all workshops of capital Aerospace Machinery Co., Ltd. of China Launch Vehicle Technology Research Institute completed the parts production on schedule.
Behind the improvement of efficiency is a number that Liu Yonghong is proud of. Through this technology, the processing speed of titanium alloy can reach 21494mm3 / min, while the highest speed of the existing EDM milling technology in the world is only 3000mm3 / min.
"We are trying to break through the key core technologies." Liu Yonghong said that at present, low-end technologies are widely used in the field of domestic mechanical equipment. In the process of transformation to high-end equipment, the requirements for "high life" of key components will inevitably increase, which means "high strength, high hardness and high wear resistance". The "little things" in the heavy weapons of a big country are the objects of Liu Yonghong and his team's "fight to death." no matter how small, if the core technology is in the hands of others, the industry's output value is no more high, and it pollutes the environment, the most important thing is that it is easy to be restricted by others. "
Once a "neck sticking" technology is broken through, it will bring great changes to aerospace, automobile manufacturing, oil and gas development and other fields. "In the field of high-end equipment manufacturing, parts manufacturing should be a process from quantitative change to qualitative change." "There is still a lot of room for our processing technology to develop," said Ji Renjie, a young team teacher
Innovation is indispensable to explore new space. In Liu Yonghong's team, the regular meeting once a week is not only the schedule of project promotion but also the center of brainstorming. Encouragement is the self described "workaholic" professor's basic attitude towards students' ideas, "never criticize students' ideas because they are naive, and no one dares to think about a blow.".
Zhang Fan, a doctoral student led by Ji Renjie, is devoted to the research of new energy batteries. Liu Yonghong encouraged him to "cross the border".
"The research actually comes from a waste product." When Zhang Fan tried to make a new type of sealing film with 3D printing technology, the wrong parameters led him to get a silver black flower like object. Except for the nickel material, Zhang Fan knew nothing about the finished product. He consults Liu Yonghong with this group of "abandoned" objects, but unexpectedly gets advice, "this is a very good new phenomenon, which should be explored deeply." The teacher's insight in the field of scientific research gave Zhang Fan confidence. He constantly improved on this basis and finally got an object similar to an electrode piece. Zhang Fan thought of reading the article about hydrogen production by electrolyzing water in the school newspaper, knowing the application scope, and finally established the feasibility of exploring the field of new energy batteries.
Zhang Fan is eager to be like his team's predecessors, and when he sees the news that China's great power is "going to the sea", he will be proud of his part.
In the view of CAI Baoping, the young teacher of the team, "we are not only studying the" screws "of the great powers, in a sense, we are studying the great powers."
In the deep sea of 1500-3000 meters, the blowout preventer with a height of about 30 meters is the last line of defense against blowout in the process of offshore oil exploitation. Almost all the BOPS used by domestic drilling platforms are imported from abroad, which is expensive and easy to be restricted. "This set of things is really a" neck sticking "technology for us. If the other side does not supply it, the whole drilling platform will be paralyzed." Therefore, Liu Yonghong and members of Caibao's equal team spent nearly 10 years to "die hard" the technology, and finally successfully developed the 3000 meter "underwater BOP control system", which filled in the blank of key underwater equipment in China's offshore engineering and broke the monopoly of foreign technology.
"I hope that the research results obtained by the team in exchange for their youth can be used in the South China Sea as soon as possible." This is Cai Baoping's biggest wish now,
