Research And Application Of Nc Machining Process For Radar Antenna Array Radiating Cavity

Airborne radar is the core subsystem in avionics systems, battlefield command network systems, missile defense systems and air traffic control systems. It consists of antennas, feeders, transmitting, receiving, terminal and basic component parts, among which the antenna plays a very important role in airborne radars. The dimensional accuracy, form and position accuracy as well as surface quality of the antenna array could impose direct impact on its microwave transmission quality. Radiating cavity is a typical aircraft thin-wall parts, along with the NC technology development, control the deformation in the process of NC machining is the parts processing difficulty.This paper investigates deeply on the numerical control machining process of radiating cavity, aiming at controlling the parts deformation and providing theoretical guidance for the actual airborne radar antenna array numerical control machining process.Firstly, this paper analyzes the material properties and structural characteristics of the radiation cavity. Based on the process features of parts, the relationship between cutting force and cutting tool, the CNC machining center and numerical control cutter for parts processing are selected. The clamping schemes is presented as well. And jigs and fixtures such as vacuum chucks are designed to effectively control the parts deformation.Secondly, the selecting principle of cutting parameter in different cutting strategy is identified based on the analysis of the four elements of cutting parameter as well as the constraint factors affecting cutting parameter selection. Different analysis method are using to determine the cutting parameters of both rough and fine machining of radiation cavity. The relation formula between the parts surface roughness and cutting parameter is established, effectively solving the problem of selecting the optimal combination of cutting speed, feed and cutting depth.Then, based on the UG CAM system, the feeding strategy is presented, including the cutting pattern from parts center to the peripheral contour, the optimization of feeding sequence among multiple cavity and the reasonable cross-regional safety flat surface to reduce the cutting path, etc.Finally, the accuracy of NC codes is verified through virtual geometry simulation by applying VERICUT software. The NC program is further applied in actual machining process. Three-coordinate measuring result of processed parts shows that the numerical control machining process proposed in this paper is suitable and efficient.The research results of this paper has significant reference value for the precision machining of aviation thin-wall parts.