Control Of ED Truing Of Grinding-Wheels For ELID Grinding

With the extensive application of hard and brittle materials, especially the ceramic material, kinds of ultra-precision machining methods get developed rapidly. ELID grinding is one of the methods which have practical application grinding technology. The technique combines the dressing of grinding wheels with the grinding process. In the process of grinding with the minute cutting with grinding wheels, the wheels are also being dressed by the nonlinear electrolysis. Thus, the phenomena of passivation and obstruction are avoided and the precision grinding of hard and brittle materials is achieved. The grinding wheel surface figure which has important influence to the grinding effect and efficiency demands precision truing. Because it is difficult to improve metal-bonded wheels figure using conventional truing methods, so ED truing technique has been developed. It is usual for the common ED truing system to have the problem like bad figure and low efficiency because of many infects. Based on the fuzzy-control theory, one computer-control ED truing system has been set up. The experiments prove that this system can improve the truing efficiency and precision obviously.First, one data-acquisition system has been set up to get the process parameters and signals based on Labview software and DAQ card. One data-output system is built to carry out voltage-control. Then the discharge voltage and current in the ED truing process has been analyzed and the discharge status has been classified and distinguished using four different methods. In the experiment, two parameters which could standing for the discharge statue, continue discharge coefficient and deviant discharge rate, has been found using the distinguishing program. The relationship between the token parameters and adjustive quantity between the electrode gap has been set up. It is used as control rules. One fuzzy-control ED truing system is built based on fuzzy consequence using control rules to control the electrode gap with computer output voltage. The experiment shows that, compared to the common system, the fuzzy-control ED truing system guarantees the stability of the process and improves the truing efficiency and precision.