Design And Realization Of Reliability Test-bed For CNC Lathe Dynamical Turret

CNC machine tools are the basic equipment of modern manufacturing. It is thesymbol to measure the industrial modernization level of a country. Dynamical turret isthe essential functional component of CNC lathe, its reliability makes an importanteffect on the quality of the integrate machine. So the reliability research of dynamicalturret has an important significance.Combining with the national science and technology major projects "High-gradeCNC machine tools and basic manufacturing equipment"–reliability design and testtechnology of the key component (Project numbers:2010ZX04014-011), this paperhas designed and realized test-bed for CNC lathe dynamical turret based on theworking condition of dynamical turret. At present, although there are some similardomestic test-beds, they cannot simulate dynamic cutting force and dynamic torque.This test-bed can provide revolving test, dynamic cutting force loading test anddynamic torque loading test, it can simulate the real working condition of dynamicalturret, and provides research data to reliability research of dynamical turret. Thispaper mainly includes these research contents:(1) According to the actual working condition of dynamical turret and requirement ofthe task, this paper has designed a reliability test-bed of dynamical turret. The basicfunction of the test-bed includes revolving test, dynamic cutting force loading test anddynamic torque loading test. Test-bed contains five parts, which are the flat earth iron,turret supporting base, cutting force loading system, torque loading system and digitalcontrol system.(2) The range of cutting force and torque is researched based on actual workingcondition. The structure of the test-bed is designed and related calculation iscompleted. The electro-hydraulic servo loading system and torque loading system with eddy current dynamometer is also designed. Dynamic force loading devices canprovide cutting force loading with different degrees, and can provide force loading atthe same time of high speed torque loading with a loading bearing.(3) The control system of the test-bed is designed. What is more, control circuit isdesigned, electric components are selected and connected, Logical sequence andaction process are analyzed. Besides, the control of PLC is completed. Feed-forwardPID control theory is applied into the test-bed. According to the functions, operationplatform and control interface are designed.(4) During the alignment and operation of the test-bed, some problems were found out,including electromagnetic interference, unstable signal, lagged waveform and impactforce coming with the end of loading moment etc. In order to manage these problems,the method such as changing the layout of control circuit and improving the loadingprogram were used perfectly. After dealing with the fault about the servo amplifiersand the sensor of lathe, the reliability test-bed of dynamical turret was establishedsuccessfully.After the completion of the test-bed, its operation is stable, and a long timecontinuous test could be implemented on the test-bed for the collection of the test data.By using the reliability test-bed of dynamical turret, we can firstly simulate the actualworking condition and collect the fault data of dynamical turret in the laboratory,which has a great practical value and great significance to the reliability study of CNCmachine tools.