Multi-field Synergy Analysis Of Electric Pneumatic Drive Alternating Impact System

As a kind of handheld electric power tool, electric pneumatic drive alternating impact hammer works with the mood of shocking and rotating based on air cushion principle. Pneumatic alternating impact mechanism is crucial to improve alternating impact characteristics and impact energy. However, researches on kinetic analysis and impact characteristics detection of linear impact mechanism detection system are less. Thus, research on multi-field synergy analysis of electrical pneumatic alternating impact system is carried out on the basis of the kinetic and electromagnetic theorem. The main contents include:Firstly, the research carries out the force analysis and movement law of the impact piston from perspectives of Aerodynamics and Newtonian mechanics. Force on impact piston mainly includes two kinds, one is the pressure difference on both sides of the piston, the other is friction force of the O sealing ring caused by the reciprocating linear motion.Secondly, the structure of magnetic velocity sensing device is designed based on original alternating impact mechanism. Then the magnetic circuit design, permeance calculation, and analysis of permanent magnet and working air gap are conducted and designed.Thirdly, the establishment of two-dimension FEM model and transient electromagnetic analysis of linear impact mechanism detecting system are conducted to calculate magnetic field of detecting system and induction voltage of windings in ANSYS Maxwell. The effects of different key structural parameters on impact characteristics are analyzed, such as the cylinder material, position and numbers of windings.Finally, simulation results are compared with measured results maintained from experiment, verifying that the magnetic circuit design and simulation model are correct in electromagnetic field, and the scheme of magnetic speed sensor to detect alternating impact characteristics is feasible.The research results show that simulation results are consistent with experimental results. Cylinder material, the location and numbers of windings have effects on the induction voltage in windings, and O ring friction has stage influence on impact energy. The conclusion can provide certain reference for further research on the optimization of alternating impact characteristics and design of magnetic velocity sensor.