The invention provides a primary gas gun quick-opening mechanism, which belongs to the technical field of primary gas gun launching, and comprises a T-shaped three-way
pipe, one end of the three-way
pipe is connected with a gas storage chamber, the lower end of the three-way
pipe is connected with a
gun barrel, a sealing ring is arranged on the inner wall of the three-way pipe, a
flange plate is arranged at one end of the three-way pipe, a circular pipe is arranged along the middle of the
flange plate, and a
piston rod
assembly is arranged in the circular pipe. The
piston rod
assembly comprises a sealing
piston, and the appearance of the sealing piston is matched with the inner wall of the sealing ring. A cylinder is arranged at the top of the protective cover, a cylinder
impact block is arranged at the output end of the cylinder, the cylinder
impact block is connected with a cross beam rod, the middle of the cross beam rod abuts against an
impact head during sealing, and the impact head horizontally penetrates through a U-shaped groove of the cylinder impact block during opening. The scheme provided by the invention can be used for carrying out ultrahigh-speed and high-frequency launch tests, meanwhile, the three-way pipe is replaced to be connected with the
gun barrel through the connecting
flange, replacement is convenient, and the
test efficiency is improved; the overall structure is simple, and
machining is easy.