A construction machinery hydraulic oil return control circuit and its control method

Abstract

The invention provides an engineering machine hydraulic oil return control loop and method. The engineering machine hydraulic oil return control loop comprises a hydraulic oil tank and a hydraulic multi-way valve set. The hydraulic oil tank communicates with the hydraulic multi-way valve set through a first oil return channel and a second oil return channel. The second oil return channel is provided with a back pressure valve. The first oil return channel is provided with an oil return control valve. The control end of the oil return control valve is connected with an electrical control valve. The control end of the electrical control valve is connected with a control mechanism, so that the control mechanism controls the position of the electrical control valve. The control mechanism is electrically connected with a temperature detecting device detecting the temperature of the hydraulic oil tank. The engineering machine hydraulic oil return control loop achieves control over three different pressure values on a main oil return channel of the hydraulic multi-way valve set, meets demands of multiple working conditions, lowers the energy consumption and improves the whole thermal balance state of the hydraulic system.

Description

technical field [0001] The invention designs a construction machinery hydraulic oil return control circuit and a control method thereof. Background technique [0002] In the hydraulic system of construction machinery, especially in hydraulic excavators, in order to prevent the suction of the rotary motor of the hydraulic actuator, it is necessary to add the first back pressure valve on the oil return line of the hydraulic system, so as to effectively protect the rotary motor, but due to If the pressure of the first back pressure valve is too high, the back pressure of the whole system will be too high, so the second back pressure valve is added to solve the problem that the back pressure value exceeds the hydraulic system’s tolerance when the return oil volume is large, and The setting value of the back pressure valve is generally above 2.5bar. In actual work, the average working pressure reaches above 4.0bar, and the peak value reaches about 7.0bar. This leads to an increas...

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Problems solved by technology

[0002] In the hydraulic system of construction machinery, especially in hydraulic excavators, in order to prevent the suction of the rotary motor of the hydraulic actuator, it is necessary to add the first back pressure valve on the oil return line of the hydraulic system, so as to effectively protect the rotary motor, but due to If the pressure of the first back pressure valve is too high, the back pressure of the whole system will be too high, so the second back pressure valve is added to solve the problem that the back pressure value exceeds the hydraulic system’s tolerance when the return oil volume is large, and The setting value of the back pressure valve is generally above 2.5bar, the average working pressure in actual work reaches above 4.0bar, and the peak value reaches about 7.0bar, which leads to an increase in the pressure of the entire system and unnecessary power loss

[0003] At the same time, when the excavator is in winter or in extremely cold weather, the low hydraulic oil temperature increases the preheating process. At the same time, the oil in the hydraulic system still needs to pass through the radiator to dissipate heat, which also affects the entire hydraulic system. temperature rise, resulting in unnecessary energy loss

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