Chapter 519

As we all know, the F-14 "male cat" carrier based fighter of the US Army is a classic combat aircraft, and its biggest feature is the design of variable sweep wings.

It can be called a miracle in the 1970s, because the variable sweep wing is not only complex, but also has very high requirements on the structural strength of the whole airframe, which is slightly poor. Under the non aerodynamic resistance and load in the changing process, the wing is easy to cause structural fatigue of the airframe and reduce the life of the whole airframe; in serious cases, it is easy to cause the airframe to disintegrate and cause accidents.

Because of this, despite the popularity of variable sweep wing fighters, only two and a half of them can be produced and widely used in the world, two of them are the United States and the Soviet Union, and the other half is Europe.

Needless to say, the United States and the Soviet Union, from fighter planes to bombers, have used variable sweep wings for a whole generation of aircraft. The reason why Europe is said to be half of them is that it has not formed a full series of variable sweep wings except for "windy" fighters.

The reason for this is very simple. Europe lacks large electron beam welding machines to make larger central wing boxes that can withstand the aerodynamic structure of variable swept wings.

Yes, the key to solve the structure of variable sweep wing is the strong central wing box.

In general, to maintain the integrity of the overall structure, the application of the overall casting process is the most secure. However, in the field of aircraft manufacturing, especially in the manufacture of advanced aircraft, every inch of space is a valuable asset for designers. It may be a joint, or it needs to install a certain equipment, or it may be a controller connected to a certain part, all in all, such a large center It is impossible for designers to ignore the wing box as a blank.

This brings a problem, that is, how to maximize the retention of the internal structure and complex cabin when casting.

In addition, all parts of the aircraft should be light and thin. Take the F-14 central wing box skin for example, the thinnest titanium alloy skin is only 0.025mm, which is only equivalent to the thickness of a piece of A4 paper.

The whole casting is easy to worry about, but it can not achieve such an extreme degree. It is bound to need complex machining in the later stage. However, the whole casting has been formed, and then machining is very difficult. The influence on the whole structure can not be ignored.

Therefore, the best way is to segment manufacturing, and then use welding to splice it into a whole, forming an integrated overall structure.

Electronic welding plays an important role in it.

Due to the good stability of hot selection, easy control, energy concentration, high speed, small welding deformation, good weld quality, all of the above, combined with the vacuum environment, can improve the utilization rate of materials, indirectly reduce the weight of the overall structure, increase the integrity of components, improve the strength, is a rare precision welding process in the aerospace field.

Take the F-14 as an example. The overall length of the central wing box is 7 meters and the width is 0.9 meters. The whole structure is composed of 53 titanium alloy parts. A total of 70 welds are made by electron beam welding. The welding thickness is 12 to 57.2 mm, and the total length of all welds is 55 meters.

As for the effect, needless to say, not only compared with the traditional welding process, the overall structure of the central wing box of the F-14 using the electron beam welding process is reduced by 273kg, but also the overall strength is very excellent, which can be seen from the F-14 accident. As long as it is not a particularly serious air accident, the overall fracture of the central wing box of the F-14 rarely occurs.

Even in some seemingly serious accidents, the central wing box is still in good condition. After recycling, it can be used as spare parts. This shows how excellent the overall central wing box of F-14 is.

Now the ej9 electron beam welding machine, which produces F-14 central wing box, is placed in front of Zhuang Jianye and others. It's absolutely bullshit to say that it's not excited, because it means that the 5-meter-long, 2.3-meter-wide and 0.8-meter-high central wing box of the advanced light transport platform is available.

We should know that the ej9 type electron beam welding machine, which can produce the 7-meter-long and 0.9-meter-wide central wing box of F-14, has a total vacuum chamber of 7.5 meters in length, 2.8 meters in width, 2.5 meters in height and 53.2 square meters in space.

It is equipped with 45KW and 110KW electron beam welding guns. The welding mechanism is mobile automatic welding. The electron beam welding gun is set on the gantry hanger in the vacuum chamber and can move along the length, width and height.

It belongs to the advanced level in the mid-1970s.

Yes, even if the F-14 is the same model, it is still not the most advanced production equipment in advanced developed countries. After all, it is the end of the 1980s. The vacuum chamber of electron beam welding in western developed countries has been more than 100 square meters. The electron beam welding gun has been replaced by flexible mechanical arm. The numerical control program written with high-precision industrial control software has already broken through the length, width and height Simple motion in three directions.

Similar to complex circular motion, multi angle motion, rotary motion can be easily realized.

Among them, the new vacuum welding equipment built by the United States for YF-22 is more changeable. Not only the electron beam welding gun can realize multi angle movement, but also it can be adjusted accurately according to the different parts and parts thickness according to the numerical control program. It has a higher degree of automation and integration, and is far ahead of the world.The Soviet Union went to the other extreme, that is, to produce Tu-160 strategic bomber and "blizzard" space shuttle, the Soviet Union, regardless of cost, built a super large electron beam welding machine with a vacuum chamber volume of 673 square meters in the Ural Mountains. Later, it thought that it had built a 1300 square meter, so-called the world's largest super large electron beam welding machine.

As a result, they were built, but when they were used, they found that these two big babies were super power consumers, especially the 1300 square meter large electron beam welding machine in the back. As long as it was used, 80% of the power of the whole Urals military production base was just like vacuuming, and all of them were pumped away by this product.

Therefore, every time the Soviets used it, they had to coordinate with other departments, and they could only use it during the low peak period from 2:00 a.m. to 4:00 a.m., otherwise as soon as the goods were turned on, the whole Urals would be cut off.

Of course, Tengfei group will not do such a big thing, because it is equivalent to the power supply of the whole southwest, which is not cost-effective.

Of course, the current ej9 electron beam welder is a little small, and the welding range is still limited, but Zhuang Jianye is not very worried, because Peng Chuan and Wei Guangping have already taken their respective teams to seriously study this key equipment. With their attainments in automatic assembly, flexible tooling, electrochemical drilling and pulsating production line, they are similar to ej9 electron beam welder The so-called key equipment such as welding machine is a layer of window paper in some aspects.

Peng Chuang didn't even bother to knock on the door. He asked Xiao Zheng next door and pushed the door in directly. Then he took the drawings on his desk. Zhuang Jianye took a look. Sure enough, the upgraded ej9 electron beam welding machine for aeroengine, which is designed by using the mechanical arm and double gun head, came out.