Hydraulic system with pressurization system for hydraulic excavator and control method thereof

Abstract

The invention belongs to the technical field of hydraulic excavators, and particularly relates to a hydraulic system with a pressurization system for a hydraulic excavator and a control method of the hydraulic system. A hydraulic oil tank of the hydraulic system is a closed oil tank, and the hydraulic oil tank is divided into an upper gas cavity and a lower oil cavity; the upper gas cavity is provided with an extraction opening and a gas inlet, the extraction opening is provided with a stop valve I, the gas inlet is provided with a stop valve II for controlling the connection and disconnection between the upper gas cavity and a gas filling tank, the lower oil cavity is connected with a stop valve III, and the stop valve III is connected with the gas filling tank through an energy accumulator; a pressure detection device is arranged on the upper gas cavity, a gas filling port is formed in the gas filling tank, and a stop valve IV is arranged on the gas filling port; and gas which does not react with the hydraulic oil is stored in the gas filling tank. The closed hydraulic oil tank is vacuumized, so that water dissolved in hydraulic oil is eliminated; and the gas filling tank is additionally arranged, so that the position above the liquid level of the hydraulic oil tank is filled with gas with certain positive pressure, and moisture and dust in outside air are prevented from entering the hydraulic system.

Description

technical field [0001] The invention belongs to the technical field of hydraulic excavators, and in particular relates to a hydraulic system with a pressurization system for a hydraulic excavator and a control method thereof. Background technique [0002] As the scope of construction machinery applications becomes wider and wider, excavators play an increasingly important role, especially in some unconventional environments, such as extreme cold and low temperature areas such as the poles and plateaus. In this environment, conventional hydraulic excavators need to overcome many technical difficulties to work normally. The temperature is low, the viscosity of the hydraulic oil increases, the hydraulic pump is easy to suck air, cavitation occurs, and the hydraulic pump is damaged, and the conventional hydraulic excavator is equipped with an open hydraulic oil tank connected to the atmosphere through a breathing valve. In a dusty environment, It is very easy to pollute the hyd...

AI Technical Summary

Problems solved by technology

The temperature is low, the viscosity of the hydraulic oil increases, and the hydraulic pump is easy to suck air, causing cavitation and damaging the hydraulic pump, and the conventional hydraulic excavator is equipped with an open hydraulic oil tank connected to the atmosphere through a breathing valve. In a dusty environment, It is very easy to pollute the hydraulic oil and seriously affect the cleanliness of the oil of the whole machine

In addition, in a low temperature environment, the water vapor precooling in the air and hydraulic oil is easy to freeze to form small solid particles, which can easily damage the entire hydraulic system, reduce the reliability and life of the hydraulic excavator, and directly fail to work normally in severe cases. thereby affecting the progress of the project

In response to this problem, the conventional method in the industry is to replace the hydraulic oil with a lower pour point, and add an auxiliary hydraulic oil heating system to improve the viscosity of the hydraulic oil and facilitate the oil suction of the pump, but this method does not eliminate the hydraulic oil tank. The water vapor in the air, and the outside air has been interacting with the air in the hydraulic oil tank through the breathing valve. This has two disadvantages. One is that the water vapor in the air above the hydraulic oil tank is very easy to condense into ice, and the hydraulic oil itself dissolves. Moisture also condenses into ice particles in low-temperature environments. Such small particles are mixed in hydraulic oil, which poses a great risk to the system; second, in dusty operating environments, it becomes easier for dust to enter the hydraulic system of the whole machine. Thus affecting the cleanliness of the hydraulic oil and reducing the service life of the entire hydraulic system

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