Variable-frequency, high-precision and ultrahigh-hydraulic pressure control loading system and method

Abstract

The invention discloses a v variable-frequency, high-precision and ultrahigh-hydraulic pressure control loading system and method. The system comprises three oil ways with the same structures; each oil way correspondingly controls one loading direction in a three-axle loading device; each oil way comprises a control system, a detecting system and a hydraulic loading system; the detecting system comprises an oil pressure sensor and a load pressure sensor; the oil pressure sensor detects the oil pressure of the corresponding oil way and the oil pressure in an oil cylinder; the load pressure sensor is arranged between a piston of the oil cylinder and a loading cushion block for detecting a load acted on a test piece by the oil cylinder in real time; the hydraulic loading system comprises an oil pool, a plunger pump, an oil pump and a stepper overflow valve connected through oil pipes to form a closed loop to finish loading and unloading of ultrahigh pressure of the oil ways; the control system obtains real-time oil pressure and load of the hydraulic system; and the stepper overflow valve and a frequency conversion mechanism are used for controlling loading, unloading and the loading and unloading speed to realize precise control.

Description

technical field [0001] The invention relates to a frequency conversion high-precision ultra-high hydraulic control loading system and method. Background technique [0002] It is a very important research method in geotechnical engineering to study the mechanical properties of rock and soil through geomechanical model tests or laboratory tests, such as the uniaxial compression test for studying the uniaxial compressive strength of rock and soil and the initial stress field. Large-scale geomechanical model tests for digging underground caverns to study their stability, etc. In these tests, it is very important to apply a certain load to the rock and soil model to simulate the stress state of the rock and soil mass. This process is usually realized by using the hydraulic control system to push the cylinder piston loading plate to exert force on the model surface. of. Therefore, the performance of the hydraulic control system has a decisive influence on the implementation and ...

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Problems solved by technology

[0004] 1. The magnification of the supercharger is generally 5-8 times, and the magnification of the same supercharger is not an accurate definite value, it is a vague boost range, which results in the maximum pressure output by the hydraulic system It is not a definite value, and the hydraulic control system also has certain uncertainties when it realizes high pressure;

[0005] 2. At present, the decompression of the supercharger can only be realized through two-stage or three-stage one-way valve decompression. Due to this characteristic of the supercharger, the supercharger has poor pressurization accuracy and stepped decompression during decompression. , unable to achieve smooth decompression;

[0006] 3. At present, the price of superchargers on the market remains high, which makes the cost of hydraulic control systems using superchargers to achieve high-pressure output high and low cost performance

In addition, the existing proportional relief valve and supercharger have strict requirements on the operating environment, and have high requirements on the cleanliness and temperature of the hydraulic oil. This sensitivity to the environment also limits the accuracy of the hydraulic control system, the place of use and service life, so it needs careful maintenance during use

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