轮廓扫描法与双球法测量螺纹中径的差异分析  

Analysis of the Discrepancies Between the Contour Scanning and Double Ball Stylus Methods for Thread Pitch Diameter Measurement

作　　者：位恒政[1] 裴丽梅[1] 崔剑秋 郭斯宜 向思思 WEI Hengzheng;PEI Limei;CUI Jianqiu;GUO Siyi;XIANG Sisi(National Institute of Metrology,Beijing 100029,China)

机构地区：[1]中国计量科学研究院,北京100029

出　　处：《计量科学与技术》2023年第6期49-53,共5页Metrology Science and Technology

基　　金：中国计量科学研究院基本科研业务费项目(AKYS1601)。

摘　　要：中径参数是评价螺纹质量的重要参数,螺纹中径的测量方法主要有双球法和轮廓扫描法。在APMP.L-S9圆柱螺纹量规国际比对中,对牙侧直线度较差的量规,两种方法的测量结果出现了较大差异。通过分析两种方法的螺纹参数计算方法发现,轮廓扫描法在进行中径计算时,需要对牙侧扫描轮廓进行直线拟合,相对双球法测量的实际接触面,存在位置平移,导致中径线偏移。因此螺纹牙侧面的直线度较差时,会导致两种方法中径测量结果显著差异,通过建立理论分析模型并实验验证了上述结论。对于螺纹塞规,轮廓扫描法的测量结果小于双球法的测量值;对于螺纹环规,轮廓扫描法的测量结果大于双球法的测量值。两种方法的差值约为左右牙侧直线度之和。该分析方法也适用于轮廓扫描法与三针法的差异分析。The pitch diameter serves as a crucial metric in assessing thread gauge quality.Measurement techniques for the thread pitch diameter predominantly employ a 1D-length measuring machine equipped with both a double-ball stylus and a contour scanner.During the APMP.L-S9-2019 cylindrical thread gauge international comparison,notable discrepancies were observed in the measurement outcomes of the two methods,especially for gauges with an inferior tooth profile.The contour scanning approach determines the pitch diameter by applying least-square fitting to the tooth profile,leading to a positional translation in comparison to the double-ball stylus method's actual contact surface.This causes the pitch diameter line to deviate.Consequently,when the straightness of the tooth profile is compromised,significant differences arise in the measurement results between the two methods.The findings have been corroborated through theoretical analysis coupled with experimental validation.For plug thread gauges,the contour scanning technique tends to yield measurements lower than the double-ball stylus method.Conversely,for ring thread gauges,the contour scanning's results surpass those of the double-ball stylus method.The differential between the two methods approximately equals the cumulative straightness of the tooth profile on both sides.The analytical methodology introduced herein is also relevant when comparing the three-wire and scanning methods.

关 键 词：计量学 螺纹中径 轮廓扫描法 双球法 牙侧直线度 

分 类 号：TB921[一般工业技术—计量学]