In the 1990 s, China's main rocket -
ChangSanJia rockets who adopts a new type of large thrust lox/lh2 engine nozzle welding problem.
Is one of the difficulties in all interlining nozzle weld length 900 meters, the nozzle wall is only 0.
33 mm, welding torch stay 0.
1 second can burn through the pipe leakage or welding.
At that time, the welding engineer Gao Fenglin relies on its own technology and experience, with more than a month, completed a large nozzle manual welding.
Rocket engine is the most important group of components, the rockets have the rocket 'heart'.
Nozzle is located in the rocket engine thrust chamber, responsible for propellant combustion of high temperature and high pressure gas heat energy into kinetic energy, it directly influence on the performance of the engine specific impulse.
In recent years, the commercial space accelerate development, low cost, short cycle, mass production can be gradually become the pursuit of direction.
Manual welding take months of production cycle, and is highly dependent on of experts and technicians, does not adapt to the market demand for mass production, the rockets enterprises began to explore the robot welding process.
Recently, private space enterprise Beijing blue arrow space science and technology co. , LTD. (
The blue arrow space)
Released a set of laser welding interlayer nozzle technology, laser welding by robots.
At present, the use of the technology of 'day magpie' (
80 tons of engine nozzle has been rolled out.
According to the staff of the blue arrow space, TQ -
12 engine nozzle diameter 1 meter above, using laser welding of robot, available only for two days.
As the follow-up process further mature, welding time or compressed to 10 hours, manufacturing cycle and cost is only about 1/10 of the nozzle of traditional manufacturing process.
12 is the blue arrow developed the first 80 tons of liquid oxygen methane engine.
The thrust chamber design work to be done in March last year, after six months, completed a short nozzle thrust chamber short-range ignition test of 20 seconds.
In January of this year, TQ -
12 gas generator to complete the first round of the ignition test.
Nozzle in large thrust liquid rocket engine working process, need to withstand severe high temperature heating, gas heat per square metre to feel close to the surface of the sun.
Most humans currently master good high temperature resistant metal materials can't bear such a great heat.
Engineers will, therefore, the structure of the nozzle to make sandwich, let propellant before entering the combustion chamber, the first high-speed flow in the mezzanine, take away the quantity of heat, so as to ensure the nozzle is not destroyed.
The rocket engine nozzle schematic image: network regenerative cooling nozzle structure has enough strength and stiffness, with engine under axial thrust, internal hydraulic pressure, strong vibration;
Also need the weight of the light enough, in order to improve the engine in esteem than;
As well as the optimal profile precision, in order to make gas expansion in the most optimal way, access to the most high specific impulse.
In the current engineering applications, the sandwich type nozzle structure are mainly corrugated plate type, slotting type and tube bundle type 3 kinds.
Among them, the control structure, according to the arrangement of the pipe, can be divided into in-line and spiral.
Blue arrow, the space used for the spiral tube bundle type structure, hundreds of 3 mm wall thickness of the alloy tube, to change the way that the helix Angle are welded together.
Nozzle cross section diagram image: network 'we need to consider not only the maturity of the technology itself, also want to consider the supply situation of the process equipment.
Whether the manufacturing cost is low, development cycle is short enough, as well as the realization of standardization, automation, energy conservation and environmental protection, etc.
'Blue arrow space high level engineer Yuan Yu said.
In the vacuum brazing, diffusion welding, laser welding, and other technology comparative analysis, and on the investigation of related equipment enterprises, blue arrow aerospace research team finally chose the process of laser welding interlayer nozzle.
This process has many advantages, including high weld strength, bearing capacity, high degree of automation, welding speed, can in the atmospheric environment operation, etc.
But before that, there is no domestic research foundation, the technology is also no relevant models of mature products in the world.
Image: robot welding rocket motor nozzle blue arrow space yuan parity, in the past more than a year of time, the team starts from the most basic welding test, completed the various tests.
To solve the problem of welding in the process of deformation and displacement of nozzle, adjust welding sequence and process parameters for many times, to find the optimal solution.
'The next step, our job is to weld more, accumulate more data, exposure and solve the potential problems as early as possible.
'Yuan Yu said.
Rocket engine nozzle image: blue arrow space blue arrow space has cooperation with laser equipment manufacturing group built robots of a complete set of laser welding equipment.
Through the use of large nozzle robot, complete the automatic laser welding.
The equipment is the most big welding power is 8000 w, 10 mm can weld depth, the most big weldable close to 2 meters in diameter, to adapt to all kinds of stainless steel, high temperature alloy, aluminum alloy, copper -
Steel welding of dissimilar metals.
Laser welding machine for welding robot