Abstract: The connecting rod is one of the core components of the engine,and its accuracy largely determines the overall performance of the engine.Among them,the bending degree and the twisting degree are two important position index of the connecting rod.According to the design requirements of the connecting rod,the high-precision measurement method of the bend degree and twist degree was studied to establish the measurement model,and the measurement error compensation method was proposed.The measurement mechanism of each parameter of the connecting rod was established,and the automatic integrated equipment for online measurement was built for experimental verification.The result showed that the repetition accuracy of the designed measurement scheme could reach 1μm,Gauge repeatability &Reproducibility (GR&R) was less than 5%,and the measurement speed of the bend degree and twist degree could reach 3s/piece.Compared the measurement data with the measurement data of the coordinate measuring instrument,feasibility of the designed measurement method was verified.

Key words: connecting rod, bending degree, twisting degree, high-precision measurement, online measurement

摘要： 连杆是发动机的核心部件之一,其精度在很大程度上决定着发动机的整体性能。其中弯曲度与扭曲度是连杆两个重要的位置度指标。根据连杆的设计要求,研究了弯曲度与扭曲度高精度测量方法,建立测量模型,并研究了测量误差补偿方法。搭建了测量机构以测量连杆的各个参数,并将各在线测量的自动化装备集成化,最后进行了实验验证,所设计的测量方案的重复精度达到1μm,重复性和再现性(GR&R)小于5%,弯曲度和扭曲度的测量节拍可以达到3s/件。将测量数据与三坐标测量仪的测量数据进行比较,结果表明了所设计的测量方法的可行性。

关键词: 连杆, 弯曲度、扭曲度, 高精度测量, 在线测量