Load sensitive hydraulic system and power controller thereof as well as crane

Abstract

The invention discloses a load sensitive hydraulic system and a power controller thereof as well as a crane. The load sensitive hydraulic system comprises a proportional decompression valve, wherein the proportional decompression valve is arranged on an oil path between a control oil source and an oil inlet of a pilot-operated handle or is arranged on an oil path between a first oil outlet of the pilot-operated handle and a control end of a first main valve; and outlet pressure of the proportional decompression valve is preset so that when the pilot-operated handle is at the biggest opening degree, the output power of a load sensitive pump is matched with the output power of an engine. Compared with the prior art, the load sensitive hydraulic system has the advantages that the adaptability of the output power of the load sensitive pump and the output power of the engine can be improved, so that a lower engine idle speed can be selected and the power consumption is reduced; the great power can be output by an oil pump when the engine is operated at a high speed, and the energy efficiency is improved; and furthermore, the engine is effectively prevented from being stalled.

Description

technical field [0001] The invention relates to the technical field of load sensing, in particular to a load sensing hydraulic system, a power controller thereof, and a crane. Background technique [0002] At present, the power matching method of the hydraulic system of construction machinery, especially truck cranes, often adopts the following schemes: 1. Use a quantitative oil pump, and configure it according to the engine idle power ≥ the maximum output power of the oil pump; 2. Use a variable oil pump with constant power (constant torque) control , by setting the constant power point to prevent the engine from stalling when the load torque exceeds the engine torque. [0003] Solution 1 has a simple configuration method, but in order to match the maximum output power of the oil pump and ensure that the engine does not turn off at idle speed, the idle speed of the engine needs to be set relatively high. Therefore, this solution cannot meet the needs of energy saving. In S...

AI Technical Summary

Problems solved by technology

[0003] Solution 1 has a simple configuration method, but in order to match the maximum output power of the oil pump and ensure that the engine does not turn off when idling, the idle speed of the engine needs to be set relatively high. Therefore, this solution cannot meet the needs of energy saving

In Scheme 2, the constant power point is a fixed value after setting, and the power (torque) of the engine changes with the change of the engine speed, and the output power (torque) is low at idle speed. 1000 to 1400rpm), its output power (torque) is greatly increased, and at this time the maximum power of the oil pump cannot increase with the increase of engine speed, so that the power of the oil pump cannot be fully utilized, so it cannot Meet energy saving needs

Images