Reliability Analysis And Assessment Of Engine Head Product Line Equipment

Reliability problem has become one of the hot spots of research in industrial manufacturing field in recent years. With the improvement of manufacturing technology level and the enhancement of usability for automotive engine, requirements for reliability of the production line equipment are highly increasing. Reliability of production line equipment directly affects the quality of product and the production efficiency, which have relationship with the production cost and market competitiveness of the enterprise. Therefore, improving the reliability of the production line equipment has become one of the most crucial tasks that engine manufacturing enterprise pay attention to solve, in which the premise and necessary links are failure analysis and reliability evaluation of the production line equipment.The paper takes one of the engine head production lines, which belong to a domestic independent brand of automobile manufacturing enterprise, as the research object. The paper also establishes the database of the production line through long-term tracking and recording of the failure situation in production sites. And sum up the production line system model respectively from the equipment and the function point. Divide the system from structural and functional point, and compare the failure frequency of each part to find out the weak links of system in production line.The paper adopts the Failure Mode Effect and Criticality Analysis(FMECA) method to analyze the failure situation of the equipment in engine head production line. Take the divided ten functional subsystems as units and define the failure source parts as agreed minimum level of fault analysis. Then analyze failure mode, failure effect and failure reason of failure components in each functional system. Grade the severe degree of failure influence and calculate the harm degree of each component. Generalize and summarize the highlighted failure problems of machine head production line system and put forward the corresponding improvement suggestions and measures which provide the basis of the reliability management and improvement of the design work for the machine head production line system.Carry the mean time between failures(MTBF)as the main evaluation index and assess the reliability of main equipment horizontal machining center in machine head product line, which are based on the failure database of product line. Take the time database between failures of26horizontal machining center in production line as the observation samples. Fit the graphics of probability density function and experience distribution function of time between failures according to the frequency of observation samples and proposes the hypothesis of obeying weibull distribution. Adopt least two multiplication method and linear conversion to weibull distribution and estimate the distribution parameters. Solve the weibull distribution model of time between failures and carry on the linear correlation test and k-s test. The results show that the time between failures of the machining center obey the estimation of weibull distribution model. Finally obtain the mean time between failures(MTBF), mean time of repair failures(MTTF), inherent availability(A) as well as reliability index such as reliability and failure rate function according to the distribution model.