Device and method for testing high-frequency on-load frequency characteristic of large-size hydraulic cylinder

Abstract

The invention relates to a device and method for testing a high-frequency on-load frequency catachrestic of a large-size hydraulic cylinder. According to the technical scheme, an oil pressing port of a hydraulic pump (18) is communicated with ports P of a three-way proportion pressure reduction valve (1) and an electro-hydraulic servo valve (20); a port A or a port B of the electro-hydraulic servo valve (20) is communicated with a rodless cavity of the hydraulic cylinder (7); a port A of the three-way proportion pressure reduction valve (1) is communicated with a rod cavity of the hydraulic cylinder (7); and the signal input ends of the three-way proportion pressure reduction valve (1) and the electro-hydraulic servo valve (20) are connected with corresponding D / A1 and D / A2 channels of a data acquisition card (13). First resistance strain foil groups are attached to the middles of the inner side and the outer side of a left vertical arm or a right vertical arm of a closed type stander (6); second resistance strain foil groups are attached to the middles of the rear side surface and the front side surface of a beam; and the two groups of resistance strain foils are connected with the corresponding channels of the data acquisition card (13) through a dynamic signal conditioning circuit module (12). The data acquisition card (13) and computer aided test software (14) are installed in a computer (15). The device has the advantages of high test precision, convenience in mounting and wide application range.

Description

technical field [0001] The invention belongs to the technical field of hydraulic component testing. In particular, it relates to a large-scale hydraulic cylinder high-frequency load frequency characteristic testing device and a testing method thereof. Background technique [0002] The hydraulic cylinder is the main actuator of the hydraulic system, and its movement speed with load determines the response speed and control accuracy of the hydraulic system. The load frequency characteristic test of a large hydraulic cylinder is an important means to measure its quality, but the frequency characteristic test of a large hydraulic cylinder is generally only carried out in the range of 0-20Hz (Zeng Liangcai, Rolling Mill Servo Cylinder Test Bench Research [J], Machine Tool and Hydraulics, 2003(3)). [0003] At present, the testing of the frequency characteristics of the hydraulic cylinder under load has attracted the attention of those skilled in the art: for example, the patent...

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Problems solved by technology

However, this test method has the following problems: (1) During dynamic measurement, the displacement sensor is prone to vibration, which affects the output signal waveform and detection accuracy of the displacement sensor; (2) The range of the displacement sensor is difficult to choose, and a larger range sensor is used to measure small displacements It is difficult to read and process the signal at the same time. During the test preparation process, it is easy to cause the sensor to be damaged due to extrusion and drop; (3) When measuring the load frequency characteristics of different hydraulic cylinders, the displacement sensor needs to be re-clamped; (4) Test The frequency range is small, generally only in the range of 0-20Hz, not suitable for extending to the high-frequency detection range of 20-50Hz

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