Variable pump hydraulic system, control method of variable pump hydraulic system, and crane

Abstract

The invention discloses a variable pump hydraulic system, a control method of the variable pump hydraulic system, and a crane. The variable pump hydraulic system comprises a control valve group (5) provided with a valve port (51) capable of achieving opening degree control, a variable pump (2) an engine (3), a first pressure sensor (71) arranged in a control valve group oil inlet channel (L1) located at the front end of the valve port, a second pressure sensor (72) arranged in a load feedback oil channel (L2) located at the rear end of the valve port (72), and an automatic accelerator controller (8) used for calculating pressure drop P1 passing through the control valve group through oil pressure collecting signals of the first pressure sensor and the second pressure sensor and comparing the pressure drop P1 with a preset pressure P0; when P1 is greater than P0, the automatic accelerator controller issues a speed decrease control signal for decreasing the engine rotation speed; and when P1 is lower than P0, the automatic accelerator controller issues a speed increase control signal for increasing the engine rotation speed. Automatic accelerator control of the engine can be achieved, the speed is regulated just by operating a hand shank, fuel consumption is reduced, and the fuel economy is improved.

Description

technical field [0001] The invention belongs to the technical field of hydraulic control, and in particular relates to a variable pump hydraulic system and a control method thereof. Background technique [0002] At present, in the industry of hydraulic devices such as cranes, the hydraulic system and power system are completely independent operation modes. In order to meet the functional requirements of the hydraulic device, a large-capacity coverage method is adopted, that is, the engine can work in the whole range. [0003] Taking a crane as an example, during the hoisting operation, the hoisting operation speed can be adjusted through the joystick, and the hoisting operation speed can also be adjusted by changing the engine speed. mode, and the handle speed control and engine speed control are all adjusted by the operator. [0004] However, since the operator cannot select the optimal and most suitable operation mode through human subjective judgment, for example, when ...

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Problems solved by technology

[0005] Aiming at the defects in the prior art that the engine speed control and the variable pump displacement control are independent of each other, such as excessive fuel consumption waste, etc., the present invention provides a new variable variable pump hydraulic system to improve fuel economy, be more environmentally friendly, and save energy.

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