An automatic idle speed system and control method based on multiple hydraulic accumulators

Abstract

The invention relates to an automatic idling system based on multiple hydraulic accumulators and a control method. Based on a power battery electric quantity storage unit, the flow changing function of a hydraulic pump is achieved through the structure that a frequency-conversion power motor is adopted in a power system for driving the constant-flow hydraulic pump, the high-efficiency driving performance and the good control characteristic of frequency-conversion speed control are fully utilized, and the power system can be matched with a load in a full-power manner. Due to the fact that a composite energy combination of a power battery and the multiple sets of hydraulic accumulators is adopted, the beneficial effects of the electric quantity storage unit with relatively high energy density and the beneficial effects of a hydraulic accumulator energy storage unit with relatively high power density are integrated, the energy density is ensured through the power battery, the first hydraulic accumulator is used for providing or absorbing instantaneous large power of a hydraulic drive system, the second hydraulic accumulator is used for providing auxiliary driving for special working conditions, and various power requirements of a hydraulic excavator in complex working conditions are met.

Description

technical field [0001] The invention relates to the technology in the field of energy saving and emission reduction of construction machinery, and more specifically relates to an automatic idle system based on multiple hydraulic accumulators and a control method for the automatic idle system. Background technique [0002] Construction machinery with low energy efficiency, poor emissions and noise needs to meet the pressure of energy conservation and environmental protection, and strive to find new energy-saving solutions in technology. Therefore, the energy saving and emission reduction of construction machinery has always been the goal pursued by the industry. Among them, hybrid drive technology and pure electric drive technology are current research hotspots. [0003] Hybrid drive technology has achieved certain results in energy saving and emission reduction of construction machinery, but there are deficiencies such as limited fuel consumption reduction, high cost, diffi...

AI Technical Summary

Problems solved by technology

[0004] 1) The energy storage units used in the hybrid power system have obvious advantages and disadvantages, and are not suitable for various complex working conditions of construction machinery, and the cost is relatively high;

[0005] 2) Unlike vehicles, construction machinery is mostly a single-pump multi-actuator system, the engine power cannot be easily reduced, and there are many energy conversion links in the system, making it difficult to greatly improve the effective utilization of energy;

[0006] 3) The load fluctuates violently during the operation of construction machinery, but due to the long hydraulic circuit, it is difficult for the hybrid power unit of the power system to dynamically compensate the fluctuation of the load in real time

[0010] 1) The speed range of the engine is narrow and the idle speed should not be too low. Generally, it only switches between two speeds with a small speed difference;

[0011] 2) When idling, just simply reduce the speed, there is still a lot of reactive power loss;

[0012] 3) When the automatic idle speed is canceled, it is difficult for the outlet of the hydraulic pump to quickly build up the pressure required to overcome the load

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