Hydraulic system of overflow-loss-free loader and control method of hydraulic system

Abstract

The invention discloses a hydraulic system of an overflow-loss-free loader and a control method of the hydraulic system. On the basis of an original hydraulic system of the loader, parts like energy accumulators, reversing valves, sensors and a controller are additionally mounted, and part simplification is performed; through corresponding control strategies, matching between output flow of a fixed displacement pump and needed flow of a load (an external load and the energy accumulator) can be realized, overflow loss can be avoided completely, and throttling loss and friction loss can be reduced; potential energy recycled is used for being provided to a steering gear, a multi-pump hydraulic system of the loader is changed into a single-pump hydraulic system, and energy is stored through the energy accumulator, so that pressure buildup time of the hydraulic system and installed power of an engine are reduced, and efficiency of the whole loader is improved. The energy accumulator is utilized to absorb pressure impact, so that stability and reliability of the hydraulic system are improved while fatigue lives of elements are prolonged.

Description

technical field [0001] The invention relates to the technical field of engineering machinery, in particular to an energy-saving hydraulic system and a control method for a loader without overflow loss Background technique [0002] Loader is a widely used engineering machinery, hydraulic system is an important part of it, generally composed of working hydraulic system and steering hydraulic system. In small and medium-sized loaders, the working hydraulic system generally uses a quantitative pump, which is likely to cause a mismatch between the flow of the pump and the load demand, resulting in overflow loss, resulting in a decrease in fuel economy and an increase in oil temperature. The working hydraulic system of large loaders generally uses variable displacement pumps, which are expensive and the hydraulic parts are sensitive to pollution. In order to ensure that the steering hydraulic system can still quickly perform full steering and improve production efficiency when th...

AI Technical Summary

Problems solved by technology

In small and medium-sized loaders, the working hydraulic system generally uses a quantitative pump, which is likely to cause a mismatch between the pump and the load demand flow, resulting in overflow loss, resulting in a decrease in fuel economy and an increase in oil temperature

Variable pumps are generally used in the working hydraulic system of large loaders, which are expensive and the hydraulic parts are sensitive to pollution

In order to ensure that the steering hydraulic system can still quickly perform full steering and improve production efficiency when the engine is idling, a large displacement quantitative pump is generally used, but a large amount of power loss will occur when the engine is at high speed

[0003] At present, the energy-saving technologies mainly used in the product include double-pump confluence technology and double-pump confluence equivalent unloading technology, but neither of them has completely solved the overflow problem, so the energy-saving effect is very limited

Komatsu has applied confluence technology in the flow amplifying valve of the steering system of its loader, but the technology is difficult and costly, and cannot be promoted on a large scale

Although variable displacement pump technology can reduce power loss, it is currently difficult to popularize due to its high cost

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