Study of Combustion Stroke of Double-Chamber Explosive Gas Forming Device

The double-chamber explosive gas forming device is a kind of pulse punching unit. The device comprises a combustion chamber and an operating cylinder separated from each other by a piston, at the top of which an elastic disc is mounted. The stamping process is carried out by the pressure of the elastic disc due to the kinetic energy of the piston being accumulated during the explosion stroke. The piston is accelerated by the pressure of a high-temperature gas formed in the combustion chamber through the gaseous fuel mixtures burnout. The explosion stroke process was analysed on the basis of the equations of rigid body dynamics and thermodynamics. As a result, the regularity of the piston motion was determined, and the optimal ratios of the geometric parameters of the stamping device were found, ensuring an increase in its effective energy. It is established that the motion pattern of a piston depends essentially on the ratios of the flow bore section of an exhaust valve and the cross section of an operating cylinder. If this ratio is less than 0.07, the piston oscillates along the length of the cylinder, which is not acceptable for the stamping process. If it is greater than 0.1, the piston moves monotonously, continuously accumulating kinetic energy, which ensures the punching process. It is also established that the optimum ratio of the operating cylinder and the combustion chamber is within the range of 1.3–2.5.