Research On Medium Force Digitization Of Aircraft Wire Harness Mechanical Positioning Point

The wire harness is fixed to the aircraft structure by clamps.In current process,the wire harness assembly quality is detected by pulling the wire harness with medium force,the application of medium force depends on the experience of assemble staff,the empirical non-quantitative test is not allowed from safety angle.The medium force is closely related to clamp installation process,in the existing clamp installation process,the nature of reasonable method for judging the clamp installation is not clear,and unreasonable fixing of the wire harness cannot be ruled out when the medium force is detected.The mere medium strength still can’t be applied to the actual wire harness assembly quality inspection,because of the quantitative detected device is missing.Secondly,the matching principle of clamp is that the nominal diameter of clamp is equal to the outer diameter of the fixed wire harness.Because the number and diameter of components of the wire harness vary with demand,the calculation of outer diameter of the wire harness is large and complicated,and the dedicated computing software is missing,which results in low efficiency of the matching of clamp and large workload of designer.In order to solve above problems,this dissertation focuses on the mechanical positioning points of the wire harness.The main research works and innovations are as follows:(1)Quantified the mechanical positioning point medium force.By analyzing the working principle of clamp fixing harness,the information of mechanical positioning point of the wire harness is extracted,and the theoretical model of medium force is established.According to the model,the medium force is quantified by analyzing clamp force;By analyzing the medium force and clamp installation process,it is concluded that the G value of the upper and lower ear gap under the working condition of clamp is the essential factor determining whether clamp fixing harness is suitable or not.It is recommended to add the detection of the G value in the existing clamp installed process.(2)Developed a cable layout and bundle diameter calculation software.By analyzing the arrangement of the circular isobaric cable and the calculation of the bundle diameter,a regular polygon arrangement algorithm is proposed to obtain the minimum bundle diameter when the cable is arranged in a regular polygon.By analyzing the arrangement of the circular non-equal cable and the calculation of the bundle diameter,the idea of directly calculating the bundle diameter of the circular non-equal cable commonly used in several projects from the geometrical point is proposed,the corresponding calculation formula is obtained.Through programming analysis of circular equal core,non-equal cable arrangement and bundle diameter calculation algorithm,in MATLAB environment,the cable arrangement and the bundle diameter calculation software was designed by using the GUI module,and the examples are demonstrated.(3)Designed a wire harness assembly quality detecting device.According to the design requirements of the testing device,the mechanical structure and electrical part of the detecting device are calculated and analyzed in detail,the wire harness assembly quality detecting device is designed for detection of the wire harness assembly quality.