A measuring device and method for studying the effect of compression force on torque coefficient

Abstract

The invention discloses a measuring device and method for studying the influence of pressing force on torque coefficient, which belongs to the technical field of precision measuring instruments. The device comprises: a pretightening force test stand and a screwdriver; There is a tension / pressure sensor, which is used to measure the pre-tightening force of the screw in the process of screwing the screw into the connected part; the screwdriver includes: a mounting cylinder, a pressure sensor, a torque sensor, an upper torque transmission column, a lower torque transmission component and a cutter head The torque sensor is used to measure the torque received by the screw when the screw is screwed into the connected part. The upper torque transmission column and the lower torque transmission assembly are respectively installed at both ends of the torque sensor, and the end of the lower torque transmission assembly located outside the installation cylinder is equipped with a knife head; the pressure sensor is used to measure the compressive force exerted when tightening the screw; the present invention can measure the torque, pre-tightening force and compressive force in the screw connection process, and adopt the method of mathematical statistics to obtain the change of the torque coefficient K under different conditions law.

Description

technical field [0001] The invention belongs to the technical field of precision measuring instruments, and in particular relates to a measuring device and method for studying the influence of pressing force on torque coefficient. Background technique [0002] With the continuous increase in the accuracy and stability of precision instruments in aviation, aerospace, military, and medical treatment, higher and higher requirements are put forward for the connection quality of mechanical products. The task of improving the accuracy and stability of precision instruments has been imminent. Among them, threaded connection is the most widely used connection because it can obtain a large connection force and is easy to assemble and disassemble. The connection is easy to achieve mass production through standardization, and the connection cost is low. Way. The quality of threaded connection directly affects the assembly quality and reliability of the entire product. From an econom...

AI Technical Summary

Problems solved by technology

First, the processing quality of small-sized screws, the dispersion of shape error, size error, and surface roughness is too large, which leads to large dispersion of measurement results

Second, the friction area of ​​small-sized screws is small, and it is impossible to directly measure the pre-tightening force and the friction force of each friction surface with a patch sensor, which makes it difficult to study the torque coefficient of small-sized screws

Moreover, most current studies on screw connections do not monitor the compression force applied during tightening

But we can't ignore the importance of the compression force when tightening the screws, especially the small size Phillips screws. For example, in the actual manual work, only a certain compression force can be used to complete the tightening process better.

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