为了得到可靠和高效的铸铁基金刚石微粉砂轮精密整形过程,建立了基于LabVIEW数据采集系统、电火花状态和砂轮圆度监控系统以及可小到纳米级进给的间隙自动实时控制系统,并在此基础上进行了针状电极试验和铸铁基金刚石微粉砂轮的整形试验.针状电极试验证明了砂轮与电极之间存在一放电圆弧区域,在砂轮转动一圈的周期内,砂轮表面某一点的电火花放电最大时间为此点转过这段区域的时间,即使再增大脉宽也不会提高材料的去除率.在电火花整形试验中,对各种电参数和不同的电介质对整形过程的影响进行了研究和选择.最后在合理参数的基础上,选用去离子水作为放电介质,整形过程稳定高效,最终得到砂轮的圆度为0.75μm,锥度误差小于0.5μm.
In order to obtain a reliable, efficient and accurate electro-discharge truing (ED truing) process of cast iron bonded fine abrasive diamond wheel, a data acquisition system, discharging characteristics monitor system, roundness monitor system and real-time control system via a nano-servo device based on LabVIEW were designed and implemented. By use of these systems, the pin electrode experiment and the ED truing experiment of cast iron bonded fine abrasive diamond wheel were performed. The result of pin electrode experiment showed that the discharging area on the wheel surface was an arc, which determined the maximum discharging time. Influences of the electric parameters such as current, voltage, duty cycle and non-electric parameter of dielectric on the ED truing process were studied. The optimized parameters were obtained, Experiments indicated that the truing process was stable and efficient, and the final roundness of the diamond wheel dressed by ED truing was 0.75μm, the taper error was less than 0.5 μm.