Research On Quality Gates Monitoring System For Assembly Process Of Engine

With the development of automobile industry, automobile engine is becoming more and more complex. As the last and most important link of production process, assembly activities directly influence the quality of the engine. This paper has made an intensive study in the online quality control of engine assembly process in order to improve the quality. Combined with the characteristics of the engine assembly process, an unified quality analysis, diagnosis, prediction and adjustment quality gate control system is proposed. This paper studied the theory and application of the system in depth and consists of the following innovation aspects:This paper analyzes the the main characteristics of the engine assembly process, combined with current situation and demand of the engine assembly process quality control, proposed one for engine assembly process quality gate control method, establish the structure and basic frame of this control method, including the entire process from quality analysis, diagnosis, prediction to adjustment.Based on the study of traditional SPC control chart, the paper use statistical quality data conversion method which based on product specification limit to manipulation quality characteristics data from similar process, convert them into the data which obedience to the same distribution in order to expand sample capacity and draw the control chart, then transform the control limits of the chart to analyze the quality data; By studying the the theory of neural networks, a BP network model which can identify the special abnormal pattern of control chart is constructed, training and Simulation of BP network with MALTAB, the simulation result proves the validity and superiority of the method, achieves the intelligent diagnosis of abnormal patterns of control charts; With the help of large number of historical data and expert experience, a assembly performance prediction model which based on grey relational analysis method is constructed, so as to achieve the prediction of assembly quality and performance.To provide technical support for improving the quality stability of the engine assembly process, the quality gates control system for engine assembly process is developed, and integrated theoretical research results into the system.