| Because of its excellent comprehensive performance,laminated material shows outstanding application prospect in aviation manufacturing field.However,due to the large difference in processing characteristics of laminated layers,the high efficiency and precision drilling technology has become an urgent problem to be solved in aviation industry.Adaptive variable parameter system of drilling technology according to between laminated material properties of adaptive adjustment process parameters,so that the laminated material has better machining quality of workpiece,the technology is the research hotspot in the field of aircraft assembly automation.In this paper,the precision drilling technology with variable parameter control is used for the composite material and aluminum alloy.The specific research contents are as follows.1.The variation characteristics of different drilling stages and the thrust force of drilling in each stage are analyzed in detail.Through the monitoring and analysis of the drilling thrust force through the laminated drilling experiment,the relation between the change of thrust force and the drilling phase of the laminated material is obtained.In the experiment,the influence of spindle speed and feed amount on the drilling thrust force is analyzed by using different drilling parameters,and the experimental results show that the feed quantity is the main factor affecting the thrust force..2.The disadvantage of use the measuring instrument to monitor the thrust force of the drilling is analyzed and through establishing the transfer model of thrust force and the analysis of the internal working current of the spindle feed motor,this paper presents the viewpoint of the indirect measurement object of the thrust force.By means of the laminated drilling experiment,the change characteristics of the main shaft feed motor current are analyzed in detail,and find the changed characteristics of the current is the same as the thrust force.And in the end,it is concluded that the parameters can be determined by the change of the motor current.3.The current of the spindle feed motor is processed with extended Kalman filtering algorithm and the main parameters are determined in drilling experiment,according to the characteristics of laminated materials,the number and position of cutting parameters change of the two layers are determined.The filtered current is treated with discrete integral,to judge the cutting parameters change of the laminated materials by the comparison of integral differential and threshold value.Finally,the control technology is carried out and the effect of the quality of the laminated materials drilling is verified by experiment. |
PDF Full Text Request