Hydraulic bucket rod control circuit for hydraulic excavating machine

Abstract

The invention discloses a hydraulic bucket rod control circuit for a hydraulic excavating machine. The hydraulic bucket rod control circuit mainly comprises a first bucket rod control valve, a second bucket rod control valve, a third bucket rod control valve, a signal switching valve and a check valve which are connected with one another by virtue of pipelines. The hydraulic bucket rod control circuit disclosed by the invention is characterized in that one third bucket rod control valve is added on the basis of the existing system, one signal switching valve is used for realizing combined control on oil return of a rod cavity by utilizing a pressure signal of a rodless cavity and an external switch signal, and thus the regeneration of bucket rod return circuit flow corresponding to working conditions outside a valve, regeneration removal and oil supplement for the rodless cavity during complete regeneration are realized. The hydraulic bucket rod control circuit disclosed by the invention has the advantages that firstly, the regeneration outside the valve is controlled by virtue of the third bucket rod control valve, and the regeneration quantity of return oil of a bucket rod is high when the hydraulic bucket rod control circuit is in a complete regeneration position; secondly, the third bucket rod control valve has the regeneration function corresponding to the working conditions, regeneration flow is utilized according to different working conditions, and thus systematic energy conservation in the different working conditions is realized; and thirdly, a regeneration manner is controlled by the pressure of the rodless cavity in the system and also can be controlled by virtue of an external input signal, and the control manner is flexible and can meet the requirements of the different working conditions.

Description

technical field [0001] The invention relates to a stick hydraulic control circuit of a hydraulic excavator, in particular to a hydraulic excavator with the stick retracted and the external valve divided into working conditions for regeneration, regeneration cut-off and complete regeneration without a rod cavity. Background technique [0002] At present, the main control valve of the stick circuit is mainly composed of the first control valve 1 of the stick, the second control valve 2 of the stick, and the regeneration cut-off valve 3. figure 1 shown. The circuit includes a stick outward swing circuit, a stick retracting circuit, and a stick regeneration circuit. Generally, the return oil of the hydraulic cylinder in the hydraulic excavator must be returned to the oil tank. If only part of the return oil of the hydraulic cylinder returns to the oil tank, the rest of the flow will merge with the pressure oil output by the pump and flow into the oil inlet chamber of the hydrau...

AI Technical Summary

Problems solved by technology

In this kind of stick regeneration control circuit, the regenerative oil port is opened in the valve core, so the oil return volume is limited, and the oil regeneration volume recovered in the stick is relatively small. At the same time, the control of oil return regeneration can only be controlled by sensing the pressure of the rodless cavity. For light load conditions such as flat ground, there is no complete regeneration or regeneration function for different working conditions, and the energy saving effect is not obvious

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