A hydraulic lifting system and a working machine

Abstract

The application provides a hydraulic lifting system and engineering machinery, a driving assembly is connected in parallel between a balance floating valve group and an oil circuit of the hydraulic oil tank, and the lifting oil cylinder is connected in parallel to the balance floating valve group; the oil suction filter, the stop valve, the plunger pump, the high-pressure filter and the lifting valve are sequentially connected between the hydraulic oil tank and the balance floating valve group; the pilot proportional valve controls the pressure at both ends of the main valve core in the lifting valve, so that the opening amount of the main valve core at different positions of the lifting oil cylinder is different, and the pressure and the flow of the output of the lifting valve are controlled. The application adopts two load-sensitive plunger pumps as power elements, and two relatively independent power sources are used for driving; the output flow of the electric proportional load-sensitive lifting valve is combined at the balance floating valve group and then input into the lifting oil cylinder, so that the lifting cylinder is controlled to act; through the cooperation of the load-sensitive plunger pump and the electric proportional load-sensitive lifting valve, the on-demand matching of the lifting pressure and the flow is realized, and the heat generation is reduced.

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