Magnetorheological-effect-based line-shaped bolt with pretightening force adjusting function

Abstract

The invention relates to a magnetorheological-effect-based line-shaped bolt with the pretightening force adjusting function. According to the line-shaped bolt, magnetorheological intensity is regulated and controlled to regulate pretightening force so as to meet connected part occasions with specific pretightening force requirements. The line-shaped bolt comprises a bolt head, sliding grooves, a bolt bar, magnetorheological fluid, an isolation ring, a volume compensator, an electromagnetic coil, a sealing ring, a piston, a sliding gasket and a reset spring. After the optimum initial pretightening force F0 of a connected part is determined, current flowing into the electromagnetic coil is regulated so as to regulate the rheological intensity of the magnetorheological fluid, and finally the shear yield stress of the magnetorheological fluid is stabilized to be the optimum initial pretightening force F0 of the connected part; then, a nut is tightened to make the sliding gasket move slightly, and finally it is determined that the force is the optimum pretightening force F0 of the connected part. After the line-shaped bolt is connected with the connected part, pretightening force detection does not need to be carried out additionally and is completed in the pretightening process, so that operation is convenient, precision is high, and time and labor are saved.

Description

technical field [0001] The invention relates to a slotted bolt with adjustable preload function, in particular to a slotted bolt with adjustable preload function based on the magneto-rheological effect. Background technique [0002] Most of the threaded connections must be tightened during assembly, so that the connection is pre-stressed before the working load, the purpose is to increase the reliability and tightness of the connection, so as to prevent gaps or cracks in the connected parts after loading. Relative slip occurs. Facts have proved that a larger pre-tightening force is beneficial to the reliability of the threaded connection and the fatigue strength of the connected parts, especially for threads with high tightness requirements such as cylinder heads, pipeline flanges, gearboxes, and bearing caps. Connection, preload is more important. However, excessive preload will lead to an increase in the structural size of the entire connection, and it will also cause th...

AI Technical Summary

Problems solved by technology

Although this method is simple to operate, when the external environment changes greatly, the physical characteristics of the force-measuring element will change greatly, and the accuracy is difficult to guarantee. Therefore, it is difficult to apply to high-precision mechanical assembly occasions

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