Research On Key Technology For Improving The Machining Accuracy Of Radome Grinding Machine

The radome, which is made of fused quartz with a body of revolution part with shell-structure, locates on the head of high speed aircraft. As an important component in radar system, radome is one of the key parts of high speed aircraft, and its machining accuracy is a key factor to determine the performance of high speed aircraft. With the enhancement of high speed aircraft capability, the demand for the accuracy of radome becomes higher and higher. Therefore, the aim of this topic is how to improve the machining accuracy of the radome, and the research in this paper centers on the machining accuracy of radome grinding machine.Based on the existing radome machining equipment situation, the machining process of radome and experimental data are analysed. The key factors which have significant influence on the precision of the radome in machining process are founded. Meanwhile, the influence of machining precision of radome is analyzed by calculating position error, tool setting error, grinding wheel error (off-centering error and profile Error), and it provides valuable basis for further effective compensation.Aiming at improving the positioning accuracy of this equipment, a software compensation method based on "error table" is applied. The position errors of the two linear axis are measured by twice frequency laser interferometer, then the errors are compensated by a compensation method of "error table". This method achieves the machine linear positioning error compensation and greatly improves the equipment's orientation accuracy.Since the tool-setting accuracy and level of automation are low, a new method of tool-setting based on acoustic emission (AE) technology is researched. The AE technique is applied to the detection of the contacting state of the grinding wheel and the workpiece, and the function of automatically setting tool is realized.In order to improve the machining accuracy of this grinding machine, a NC form dressing method was adopted to dress the resin bond spherical-surface diamond grinding wheel. With reasonable tool-path planning and dressing parameters, this dressing method is able to fulfill the low cost and rapid dressing of diamond grinding wheel.At last, the results of correct error compensation are validated by repeated measurement experiment, tool presetting experiment and grinding process experiment. The experimental results show that position error and tool setting error are compensated effectively, and the machining accuracy of radome grinding machine is improved significantly.