QUANTITATIVE DISPLACEMENT HYDRAULIC CONTROL SYSTEM FOR CRANE AND CRANE

摘要

Disclosed is a quantitative displacement hydraulic control system for a crane, which comprises a metering oil cylinder (8), a first reversing valve (2) and a safety valve (6). An oil inlet of the first reversing valve (2) is communicated with a hydraulic oil source. A first oil outlet and a second oil outlet of the first reversing valve (2) are respectively communicated with a rod cavity and a rod-less cavity of the metering oil cylinder (8). An oil return opening of the first reversing valve (2) is communicated with an oil tank. The rod cavity of the metering oil cylinder (8) is communicated with a cavity of an amplitude variable oil cylinder through the safety valve (6). When the crane is used for hoisting a heavy object, the ascending or descending displacement required by the crane can be detected in advance for determining the hydraulic oil required by the amplitude variable oil cylinder, the required hydraulic oil is accurately provided for the amplitude variable oil cylinder through the metering function of the metering oil cylinder, or the hydraulic oil required to be discharged in the amplitude variable oil cylinder is accurately discharged, and further, the quantitative displacement of the crane is accurately controlled, so the hanging operation can be easily and precisely completed. Also disclosed is a crane with the quantitative displacement hydraulic control system for a crane.