Research On Reliability For Machining Center Human-Machine-Enviroment System

The traditional reliability analysis methods for NC Machine Tools which aim at the failures occurring in the Machine Tools in each subsystem and the primary device and the spare part to carry on analysis of the reason, the pattern and so on, conside only the influence of Machine itself purely, but the Human and the Enviroment whick are very important factors in a series of processes such as production,manufacture,maintance and so on.It indicates that, through the analysis of the failure, the reliability of the NC Machine Tools is decided not only by the performance and quality of the machine itself,but also by the handler and the environment.Therefore, it can only receive the prospective effect to research the reliability of the Machine Tools by taking the Human- Machine-Environmental factors as a whole system.1.FMEA of Machining Center Human-Machine-Environment SystemThis thesis utilizing ergonomics theory, consides the whole Machining Center system as a Human-Machine-Environment System synthetically.It outlines the failures and the reasons in aspect of human, machine, environment, and carries on the FMEA analysis by classifying the reasons. Firstly carries on the whole machine FMEA analysis, discovering the pattern, part, reason of the failures as well as classifying the reasons. As to the subsystem FMEA analysis, it takint the two sub-systems-CNC System, Main-axle part-for example, carries on failure reason and reason classification analysis separately, to discover the influence and influence degree of human, machine, environment.2. FTA of Machining Center Human-Machine-Environment SystemThis thesis takes the failures which occur in the working of one type Machining Cenrer for example; considing the whole Machining Center system as a Human-Machine-Environmental system synthetically analysisreliability of system using FTA. Firstly, when establishing all levels events of the failure tree, fully considering the Human and the Environment influence, take Human fault as well as the basic influence factor as the elementary event. Secondly, utilizating the least shear collection and least alley collection theory, separately extract the least alley collection of each failure sub-tree, and then obtain the least alley collection of the overall system failure tree. At last, find out the way to avoid or reduce the failure of the Machining center.3. Reliability Improvement for Machining Center Human- Machine-Environment SystemThrough analyzing and researching we can get the each kind of factor which affects system failures. This chapter, fully utilizing ergonomics theory, linking to reality, discovers the influence aspect to the Human and the Machine tools reliability from the control panel, the work place, the work color, the work time as well as the management &use and so on , and proposes the corresponding reliable improvement measures. Concretely it includes to improve the highty of control panel and make the display unit and the pressed key human, to make reliability design in the work site from illumination condition, ambient temperature, noise influence improvement, work place and so on.And when refers to color reliability design,it includs color design of NC Machine Tools, the work site, the caution sign.After the introduction of biological clock theory as well as the influence to operactors, it carrys on reasonable arrangement of the work time. Finally from the maintain to Machine Tools, the choice and training to operators, the power supply quality and so on, it comes to the reasonable use and the scientific management to the NC Machine Tools.