Since 1987 entered the factory, Xu Liping has been engaged in micro-shaping of missile solid fuel engine propellant. Solid fuel engine is the heart of strategic and tactical missile equipment and the key component for launching manned spacecraft rockets. There are thousands of processes in its manufacture, among which the most demanding process is the micro-molding of engine solid fuel. Carving solid fuel, that is, gunpowder, is extremely dangerous. A careless spark can cause combustion or even explosion.
Powder molding is a difficult problem all over the world and cannot be completely replaced by machines. Cutting force depends entirely on the workers' own judgment. Powder forming is irreversible. Once you cut too much, or leave a knife mark, the accuracy of the powder surface will not match the design. After the engine is ignited, the powder cannot burn in the predetermined direction, and the engine is likely to deviate from the track or even explode. 0.5 mm is the maximum permissible error of solid motor powder surface accuracy, and the powder surface error of Li Xu's hand carving is less than 0.2 mm, which is perfect, which makes his masters far behind.
During the period of 1989, the development of key engines in China entered a critical stage, and cracks appeared in the powder of an engine that was about to be tested. In order not to affect the follow-up development progress, but also to explore the remedial measures of irreversible engine charging, the expert group decided to explore on-site powder digging for the first time. Plastic surgeons have to get into the narrow lines of the engine, and it is difficult to turn over, and dig out the filled powder bit by bit to find the problem part. With superb skills and courage, Xu Liping joined the drug-digging commando. After more than two months of difficult drug digging, the engine fault was successfully eliminated. However, after being exposed to gunpowder for a long time in a confined space, the toxic attack of gunpowder made Xu Liping's legs lose consciousness, and he gradually recovered after intensive physical training.
In order to eliminate potential safety hazards, Xu Liping also invented and designed more than 20 kinds of powder shaping tools, two of which were patented by the state, and one was named "flat knife" by the company.
After years of carving gunpowder and the sequela of posture gunpowder poisoning, Xu Liping's body became tilted to one side, and his hair lost more than half. For 28 years, he was willing to be lonely and took great risks to carve gunpowder, and was known as a "great country craftsman".