Vibration Analysis Of The Wire Electrode In HS-WEDM

The wire electrode's vibration state is one of the important factors that have an impact on high-speed WEDM process stability. In order to ensure processing quality and improve cutting efficiency, it is necessary to limit the vibration of the wire electrode. The wire electrode's vibration is a complex combination of vibration that includes not only high-frequency vibration, but also low-frequency vibration. In direction, with the exception of horizontal vibration in the direction of two-dimensional plane perpendicular to the wire electrode's running, there is vertical vibration along the wire electrode's running direction. The main sources of the wire electrode's vibration are the idler pulley and bearing's axial play and radial sway, rolling tube's radial sway and wire frame's vibration, the wire electrode's flutter after the uneven heating, the wire electrode's flutter because of the instability of the working fluid's injection pressure instability. To the electrode wire, its natural frequency and vibration modal are not only associated to initial conditions and boundary conditions, but also to the wire electrode's tension and axial velocity. The biggish factor impacting on the quality of WEDM machining quality is the wire electrode's low-frequency large amplitude horizontal vibration.In this paper, the impact of the HS-WEDM wire electrode's vibration on processing is researched, the HS-WEDM wire electrode's vibration is analyzed in depth, countermeasures and solutions are put forward.In this paper, the tension string's theoretical model of the wire electrode's vibration is established, the wire electrode's forces is analyzed, the wire electrode's vibration differential equation is established, the wire electrode's modal is deduced, the frequencies of the wire electrode's low-frequency vibration are gained by theoretical calculation. Then, the tension string mode is established by using the finite element analysis software ANSYS10.0, the wire electrode's lower-order modes and frequencies are gained by using subspace iteration method for analysis. In the end, the process tests are carried out, the wire electrode's tension signal and vibration signal are collected, the spectral analyses are carried out, theoretical values and ANSYS simulation values are compared, the correction of the tension string model is verified.The following conclusions are gained by analyses and experiments:HS-WEDM cutting accuracy is mainly impacted by the wire electrode's low-frequency vibration, the wire electrode's low-frequency is impacted by tension fluctuation and the wire electrode's running velocity, using constant tension system is the main approach of suppressing the wire electrode's vibration.The wire electrode's vibration has its inherent vibration frequency, so we should optimize the design of HS-WEDM the wire electrode's running mechanism and improve the dynamic stiffness of the wire frame and make the frequencies of wire frame, motor, idler pulley away from the wire electrode's natural frequencies in order to reduce the impact on the wire electrode's vibration.The device of limiting amplitude can be used to effectively control the vibration of the wire electrode, but the current contact-type limiting device easily aggravates the abrasion of the wire electrode, and its own abrasion will reduce the effect of Vibration suppression, so the design of a new type non-contact limiter device is the fundamental approach that suppresses the wire electrode's vibration and improves the machining precision.