Load-sensitive hydraulic system and bulldozer

Abstract

Te invention discloses a load-sensitive hydraulic system and a bulldozer, and belongs to the field of mechanical manufacturing. The system comprises a pump 1, an oil tank 3, a main circuit and a control circuit, wherein the main circuit comprises a pressure compensation valve 7, a main reversing valve and a work oil cylinder, the main reversing valve is a six-way reversing valve, the main reversing valve is provided with an input end, an output end and a control end, the input end of the main reversing valve is connected with the pump 1, the output end of the main reversing valve is respectively connected with the work oil cylinder and the oil tank 3, the inlet end of the pressure compensation valve 7 is connected with the outlet of the pump 1, the oil return end of the pressure compensation valve 7 is connected with an inlet of a filter 2, and a spring control port of the pressure compensation valve is communicated with the outlet end of a shuttle valve 5. According to the technical scheme, on the basis of the six-way multi-way valve, by means of a pressure compensation technique of the single-pump system, the structure of the whole system is simplified, development cost can be effectively reduced and system performance is improved.

Description

technical field [0001] The invention belongs to the field of mechanical equipment manufacturing, and relates to a hydraulic system, in particular to a load-sensitive hydraulic system and a bulldozer. Background technique [0002] At present, the hydraulic system of bulldozer working device mainly has two forms: one is the variable pump load sensitive hydraulic system. Due to the high cost of use, it is generally used for medium and high-power models; the other is the fixed-quantity pump open center bypass throttling speed regulation system. The latter form is widely used in small and medium power models because of its simple structure and convenient maintenance. [0003] But the lack of performance of the latter system is also obvious. Aiming at the deficiency of the bypass speed regulation system of the quantitative pump, there is a load sensing hydraulic system for construction machinery in the prior art. The main pump adopts the quantitative pump and a pressure compensa...

AI Technical Summary

Problems solved by technology

However, the design of this system is complex and has certain deficiencies: 1. It adopts a relatively complicated eight-position reversing valve and a two-way pressure reducing valve to realize load sensing, which is costly; Flow rate (at low engine speed), when the handle is wide open, the large chamber of the oil cylinder may have design quality problems such as air suction and drop vibration. Although this design is equipped with an oil replenishment check valve on the large chamber, the pipeline oil path is limited , otherwise the design of the pump displacement must be increased

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