Surface Burning Of High Speed Reciprocating Wire Electrical Discharge Machining Under Large Cutting Energy And Servo Control Research

In recent years, researchers have been trying to improve the cutting quality and precision of HSWEDM, but stable cutting efficiency has not been too great improved. One of the main reason is that under the condition of high power cutting, the workpiece surface can produce burns stripes, seriously affect the quality and life of wire electrode cutting surface, at the same time, the lag of servo feed way also have a big impact to enhance the efficiency of cutting. In view of the above affect the efficient cutting points, this article from the following several aspects to carry on the research of the system, and the main contents are as follows:(1) Under the large energy cutting, the surface burning is mainly due to that a large amount of working fluids vaporize and that the discharge debris cannot be removed in time, which burns the workpiece surface;(2) The influences of forward and reverse cutting of HS-WEDM, duty ratio, and wire speed on the surface burn are also analyzed. A method for adjusting forward and reverse duty ratio to improve the surface quality under large energy cutting is introduced. A new mode of variable speed reciprocating wire electrical discharge machining is designed, which can guarantee machining efficiency and can reduce surface burn.(3)Designing two kinds of servo control method based on the probability of pulse discharge detection. A kind of based on hall current sensor to detect probability of discharge signals and through the single chip microcomputer to calculate discharge control machine feed at the same time,this way can directly use the traditional machine without the need for a big modification to machine, but depends on the response speed and precision of hall current sensor, Another way to corresponding modification of the machine, put the machine pulse pow er and the discharge of probability detection servo control together, through software to edit control interface, is convenient and practical, and cost low.(4) The relationship of polar distance and the discharge waveform were analyzed, namely the interelectrode distance shortened, discharge waveform breakdown delay time is less. When polar cannot deionization, discharge will be the transition discharge(no discharge delay time), until finally be a short circuit.(5) Verified servo control mode based on the probability of discharge detection can realize inter-electrode distance control on the cutting direction, through the discharge waveform can be seen that with the increase of setting target probability value, the s horter the polar distance, the more stable processing.(6) Select the reasonable processing parameters, test the servo control method based on probability of discharge detection of large energy under the influence of surface burn. Getting the new control method can better reduce the great energy surface burn problem, And under the condition of constant external processing conditions(working fluid, workpiece materials, spray, etc.),it will increase stable machining efficiency by nearly 50% or so.