| CNC machine tools are the strategic manufacturing equipment of the country, its manufacture technology reflects a country's industry modernization level directly. The turret tool is the essential functional component of CNC lathe, its quality makes a important effect on the reliability of the integrate machine, so the improvement of the reliability for the turret tool has a important significance on the enhancing the reliability of the integrate machine. At present, although some related domestic enterprises have some simple test-bed about turret tool, they can only make some function experiments, that is revolving test. But when a turret tool is working, it must stand a dynamic cutting force, so the revolving test can't imitate the real manufacturing environment, and the results from the test are also not satisfied.Combined with the national science and technology project-reliability design and performance test of high speed and high precision CNC machine tools (Project number:2009ZX04014-011),based on the turret tool's real working environment, this paper has designed and realized the reliability test-bed for CNC lathe turret tool. Through the acceleration test, the hidden failure of the turret tool can be exposed in short time and it can provide the basis for the reliability research of the turret tool.The main researching work is as follows:(1) The working principle and loading condition of turret tool are analyzed, and according to the turret tool GB,the revolving test and dynamic loading test are proposed. With the proposing of the test methods, the function demands of test-bed are analyzed. Based on the function demands of test-bed, the overall design of the test-bed is confirmed. The test-bed is made up by four parts, the bed gantry, electrohydraulic servo loading system, lower PLC control system and upper computer monitor control system.(2) According to the test's function demands, the structure of the test-bed is designed and manufactured. Based on this test-bed, the turret tool can be loaded on different degrees. The Finite Element Analysis of the test-bed's structure is also complete through ANSYS, according to the analysis results, the weak points of the structure is improved. After that,the electrohydraulic servo loading system is also designed, the function and principle of electrohydraulic servo loading system are analyzed, the performance parameter of important parts in the system are calculated。(3) OMRON PLC is chose as the core of the lower control system, much work is done, for example, analyzing the working principle of the servo control box, choosing the type of PLC, defining the address of the I/O, analyzing the control process of the system and so on, at last the program are achieved and the control function of the PLC is realized.(4) Visual Basic is chose as the development software of the upper computer monitor control system. The user Interface is programmed. Based on the communicating functions of Visual Basic MSComm component, the communication between computer and PLC is completed perfectly and all control of the lower control system is completed. At last, Access database is developed in order to save the test date and failure data of the turret tool.After the adjustment of the test-bed, the test is carried on for many days. The result indicates:The function of the test-bed is up to standard and the performance is steady. The test-bed meets the test requirements. The test also provides some dada and some failure of turret tool is exposed. Certainly, the failure is analyzed and resolved. The reliability test-bed of CNC lathe turret tool makes a significance and reality worth for the deeply reliability research of CNC Lathe Turret tool. |
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