A thread torque and pretightening force measuring device for small-sized bolt fasteners

Abstract

The invention belongs to the field of aerospace technology, and provides a thread torque and pretightening force measuring device for small-sized bolt fasteners, comprising a pretightening force measuring part, a connected part coaxial with the output end of the pretightening force measuring part, The torque measuring part coaxial with the connected part, the pre-tightening force measuring part is used to detect the pre-tightening force during the bolt tightening process, the connected part is used to generate the pre-tightening force and transmit the torque generated during the bolt tightening process, the torque measuring part Used to detect thread torque generated during bolt tightening. The invention measures the pre-tightening force and thread torque of small-sized bolts with high precision through the method of equivalent force transmission, and can calculate parameters such as torque coefficient and end-face friction torque by combining the total torque and pre-tightening force, and the end-face friction can be controlled by replacing gaskets coefficient, which facilitates the testing of small-sized bolts in the aerospace field.

Description

technical field [0001] The invention is used in the aerospace field, more specifically, it is a device for measuring thread torque and bolt pretightening force of small-sized bolts. Background technique [0002] Bolt connection has the characteristics of simple structure, convenient assembly and disassembly, and reliable fastening, and is widely used in the fields of machinery, electric power, and aerospace. In the complex structure of aero-engines, there are a large number of assembly joints that are fastened by bolts, such as engine casings, compressor rotors, etc.; the installation of wind turbine rotors also uses bolts, and the key to bolted connections lies in the preload. Force control, high precision pre-tightening force control can ensure uniform deformation and improve connection life. [0003] At present, there are three main methods for measuring bolt pretightening force: [0004] (1) Measure the preload by tightening torque [0005] First set a torque value fo...

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Problems solved by technology

[0008] Among them, the bolt elongation method uses ultrasonic measurement to measure the bolt pretightening force more. The ultrasonic measurement method uses the change of the bolt elongation after tightening to cause the ultrasonic rebound wave to change, but the ultrasonic measurement needs to be pasted with a piezoelectric ceramic sheet. The bolts used in some parts of launchers such as rockets are very small, and the pre-tightening force and torque of the bolts are also very small. At the same time, piezoelectric ceramic sheets are not suitable for pasting small bolts, so that the thread torque and bolt pre-tightening force are difficult to be accurate. Measurement

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