Test method for magnetorheological-fluid floating property and tester thereof

Abstract

The invention provides a test method for magnetorheological-fluid floating property and a tester thereof. The tester includes a liquid holding means for magnetorheological fluid and a capacitance sensor, wherein the capacitance sensor measures the subsidence speed of magnetorheological fluid. According to the feature that a rapid change is in concentration of ferromagnetic particles when the capacitance sensor passes a sinker-layered line, the capacitance also changes sharply. By scanning graphically a capacitance-height curve in different time of areas, the displacement of the sinker-layered line is achieved. By measuring the capacitance-time curve of a point, the time from the sinker-layered line to the point is achieved and the subsidence speed of magnetorheological fluid is calculated. With the method and the tester, the magnetorheological fluid is monitored by the capacitance sensor without an outside magnetic field in vertical direction and the magnetic field in horizontal direction is very weak, accordingly the influence of outside magnetic fields on magnetorheological-fluid floating property is removed.

Description

technical field [0001] The invention relates to a test method and a test instrument thereof, in particular to a test method and a test instrument for the suspension stability performance of a magnetorheological fluid. Background technique [0002] As a smart material with excellent performance, magnetorheological fluid has been widely concerned by people. Magnetorheological fluids are generally mixed with micron-sized soft magnetic particles (usually carbonyl iron powder), carrier liquid and functional additives. At present, magnetorheological fluid has been used in polishing technology, construction, automobile, military, aerospace and other fields. [0003] Due to the large density difference between the dispersed phase and the continuous phase in the magnetorheological fluid, the magnetorheological fluid will settle, and the sedimentation of the magnetorheological fluid will seriously affect its performance. Therefore, the evaluation of the suspension stability of the ma...

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Problems solved by technology

[0005] Chinese patent "2004200638777" placed the container containing the magnetorheological fluid in a moving magnetic field for testing. The moving magnetic field would interfere with the settling process of the ferromagnetic particles themselves, so the measured results were unstable.

Chinese patent "201110003447.0" uses X-ray luminescence system and imaging system to analyze and obtain the distribution of magnetic particle concentration in the container, but the X-ray emission system is expensive and there are personal safety problems when using it

Chinese patent "201510101330.4" uses a manual sliding scale to measure the sedimentation rate of the magnetorheological fluid sedimentation layer line. The operation is cumbersome, and manual operation will bring errors to the measurement, making the measurement results inaccurate

Chinese patent "201410298389.2" adopts the inductance scanning technology to scan the test tube containing the magnetorheological fluid, uses the solenoid sensor to nest outside the test tube, and determines a certain However, the inductive sensor will generate a certain magnetic field when measuring, which will interfere with the sedimentation movement of the magnetorheological fluid particles in the test tube, and the inductive sensor has the magnetic flux side leakage effect, and the longitudinal dimension of the inductive sensor is large (leading to Accuracy is not high), these will produce a large measurement error

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