Research On The Key Technologies Of Crankshaft On-line Measuring Machine

As the core part of the automobile engine,the quality of the crankshaft directly affects the pros and cons of the engine performance.Therefore,the machining accuracy of its various tolerance of form and positions is very high.At present,the manufacturing and processing technology of crankshaft is becoming more and more mature,and its manufacturing accuracy and efficiency have been greatly improved.However,traditional manual measurement and single measurement instruments cannot meet the high-precision and efficient measurement requirements,and it does not match the development trend of online measurement in intelligent manufacturing.This paper studies the key technologies in crankshaft measurement,including crankshaft on-line synchronous measurement technology,error analysis and compensation technology,and form and position error evaluation data processing technology.First,this paper analyzes the functional requirements of the crankshaft online measurement system,analyzes the detection requirements and characteristics of the most important journal detection,and studies its common measurement methods.This paper proposes a journal synchronous measurement scheme and designs a follow-up journal synchronous measurement structure.This structure can measure the main journal and the connecting rod journal at the same time,reducing the influence of errors caused by the random circle runout and the probe movement,and ensuring the measurement efficiency and repeatability.The shaft measurement is compared with the calibration method to reduce the influence of temperature on the measurement results in the online measurement environment.Secondly,this paper analyzes the influence of errors in the proposed measurement scheme.The sources and properties of measurement errors are studied,and the analysis is mainly made on the axis offset errors in the measurement structure,the errors caused by the temperature in the online measurement environment,and the gross errors mixed in the data collection.The influence of several errors on the measurement results is studied,and corresponding solutions are proposed.Thirdly,this paper studies several methods for the evaluation of journal position errors.The calculation methods of least square method and minimum area method are discussed.Aiming at the complexity of the calculation process of the minimum area method,genetic algorithms and particle swarm optimization algorithms were introduced to optimize it,and a calculation process suitable for the evaluation of journal errors was designed.By comparing the calculation results of crankshaft sample data with several schemes,the feasibility and reliability of the intelligent optimization algorithm are verified.Finally,we designed and developed an on-line crankshaft measuring machine and applied it to related companies.Through multiple measurement experiments,the feasibility and effectiveness of the synchronous measurement scheme,error separation compensation scheme and data processing method proposed in this paper are verified.