Inertial Igniter of Small Thermal Batteries for Artillery Munitions

This paper presents a simple-structured inertial igniter for thermal batteries of gun-fired munitions, where the setback acceleration generated by gun firing is employed to activate the thermal batteries. The inertial igniter, composed of a ring-shaped slider supported by a spring, a striker held by locking balls, a percussion primer, and a housing, provides striking action (to the percussion primer) for thermal battery activation only when the setback acceleration time profile satisfies the predetermined threshold, thus preventing accidental ignition. A theoretical analysis and an ANSYS dynamic analysis were conducted to estimate the dynamic behavior of an inertial igniter under setback acceleration, thereby informing the design of the inertial igniter. The efficacy of our design methodologies was fully validated through shock tests for the inertial igniter. While both methods yielded reliable estimations, the theoretical analysis-based method proved to be more efficient in terms of calculation time and effort than the simulation-based one.