螺纹作用轴线检测方法与技术的研究

With the development of space technology and modern weapons, not only the demand of reliability and service life of the threaded joint is higher and higher, the thread coaxiality of the parts connected by thread is also becoming more and more demanding, thus how to detect the thread coaxiality becomes a problem needed to be solved urgently. The effective axis is one of the important indicators which affect the accuracy of the threaded coaxiality. At present, most of the thread detection technology is concentrated in the integrated measurement of single parameter, but it is rarely involved in the theories and methods of the measurement of the effective axis which is influenced by multiple parameters. The goal of our project is to detect the effective axis. With the rotation of thread, the probe of sensing system which uses elements of the reference thread closely meshes with the measured thread. This method simulates the process of screwing connections, and reflects the combined effects. Using the idea of double floating to design the mechanical structure of the sensor system, we have solved the problem that probe does not match the position of the measured thread during the process of measurement. With the combination of virtual reality technology and experiments，we establish an evaluation system to make up for the defects that the measurement of thread parameters is separated with comprehensive quality of the thread. The results of our research provide a technical approach for the detection of the axis of the threaded role, which has important theoretical significance and great application value in precision machinery industry.

随着空间技术和现代武器的发展，不仅对螺纹联接的可靠性、使用寿命提出了很高要求，而且对利用螺纹联接的部件之间的同轴度的要求也越来越高，因而螺纹同轴度检测的问题应运而生，亟待解决。螺纹作用轴线是影响螺纹联接件同轴度精度的重要参数，目前螺纹检测技术多数集中在单项参数的测量方面，而对多个参数综合作用结果的螺纹作用轴线的测量理论和方法鲜有涉及。本项目以检测螺纹作用轴线为研究对象，提出一种螺纹工件旋转，以标准螺纹轴向切片作为传感系统的测端，与被测螺纹紧密旋合的测量方案，该方案模拟螺纹旋合联接过程，体现了综合作用效果；采用双浮动的思想设计传感系统，解决旋转测量过程中测端与被测螺纹位置不匹配的问题；利用虚拟现实技术和实验相接合的方法，建立评价体系，弥补螺纹参数测量与螺纹综合质量脱钩的缺陷。研究结果为检测螺纹作用轴线提供一种技术途径和理论依据，对于精密机械行业具有重要的理论意义和应用价值。

螺纹作用轴线是影响螺纹联接件同轴度精度的重要参数，目前螺纹检测技术多数集中在单项参数的测量方面，而对多个参数综合作用结果的螺纹作用轴线的测量理论和方法鲜有涉及。.本项目提出了一种基于数字化包络轮廓面的螺纹综合参数测量法。被测螺纹轮廓与标准测端轮廓紧密旋合，体现了任意轴截面内被测螺纹与标准螺纹的实际旋合状态，直接反映了螺纹各单项参数误差引起的综合实际误差。基于平面浮动思想设计的螺纹测头，可实现与被测螺纹在紧密旋合状态下的实时测量。系统的自动定位功能可以解决由于工件安装造成的测端与被测螺纹位置不匹配的问题，能够实现被测螺纹与测端初始旋合位置的匹配，保证传感系统与被测螺纹能始终紧密旋合，确保系统量程的合理分配。测端与被测螺纹的相对螺旋运动，实现了空间三维的全方位测量，根据测量数据可以得到螺纹的作用轴线，从而评价被测螺纹的装配质量。.在项目组成员的共同努力下，完成样机两台，其中一台作为横向项目的产品交付甲方，一台作为进一步研究的实验平台。样机的直线轴的运动精度优于0.001mm，旋转轴的运动精度优于10″。样机可实现现场标定，满足3级外螺纹和4级内螺纹的精度要求。作用中径测量重复性为0.004mm，作用轴线测量不确定度为5’’。研究结果为检测螺纹作用轴线提供一种技术途径和理论依据，对于精密机械行业具有重要的理论意义和应用价值。