Reserch On Cold-test Technology Of Diesel Engine

As customers increasingly improve the requirement of the quality on engine manufacturing and performance,the study of Cold Test Technology to accurately detect and quickly diagnose engine faults is paid more and more attention to both domestic and abroad.Weichai Power Co.Ltd.currently has used diesel Cold Test testingequipments in automatic test process without human interventions,having a complete off-line analysis system,which can analyse 542 parameters,such as,starting torque signal,oil pressure value signals,and so on.In addition,Cold Test Technology,using high-performance server and database storage for each engine test data,has provided detailed quality reports for the diesel engine performence analysis through statistical analysis methods.This article begins with the actual production of WP5 / 7 engine to analyze the operating principles of the engine Cold Test.By a large number of defect fault test combining with practical production,we have studied the principles of Cold Test Technology and its implementation.And the main innovative points are as follows:(1)To verify that each sensor of the test system meets the system requirements for measurement,this study focused on WP5/7 cold test system's design and test parameters,as well as measurement systems analysis methods.(2)A lot of engine defect test results are designed and carried out.Also we inferred the different types of engine failure parameters variation in cold test during the test.(3)We have improved the cold test fault repair guide database,based on the engine defect test,by combining with the failure mode of diesel engine production and application process.This article developed a set of practical cold test fault diagnosis method and conducted tests and defects in the production process the implementation of the application,in addition,this firmly confirmed the diesel engine cold test technology can be used as an effective tool to examine the quality of the engine.(4)In the application process cold test system,using a variety of analytical tools such as feature value histogram and scatter plot characteristic values and so on,we developed a cold test parameters defined range of values,and formed a complete revision of cold test process to improve the process control parameters.And therefore,cold test system can continuously improve the control range depending on the engine model parameters change,this way can ensure the cold test control parameters effective and controllable.After the practical use on the engine production line,the study proves that engine Cold Test is an important and efficient means of detection in the process of engine production,with the advantages of short testing time,high precision,low cost and less pollution.Application of cold test technology makes the engine do a very strict process detection before entering Hot Test,more important,it can discover malfunctions of engine in adcance to improve product quality.