Hydraulic system, hoisting mechanism and engineering machinery

Abstract

The invention discloses a hydraulic system, a hoisting mechanism and engineering machinery. The hydraulic system comprises an execution part, a main valve used for reversing of the execution part and a brake used for braking the execution part, wherein the brake is in an open state during oil-taking and in a closed state during oil-returning. The hydraulic system further comprises a brake oil way which is connected between an oil source and the brake, and a first control valve is arranged on the brake oil way, and opens or closes the brake oil way according to load pressure of the execution part and output pressure of the main valve. The hydraulic system can effectively prevent a load from driving the execution part to move, can avoid hook gliding when applied to the hoisting mechanism, and has the advantages of high safety, high reliability, small braking block abrasion and the like.

Description

technical field

[0001] The invention mainly relates to the field of hydraulic pressure, in particular to a hydraulic system, and a winch mechanism and engineering machinery including the hydraulic system. Background technique

[0002] The winch mechanism is an important executive component of construction machinery such as cranes, and it is mainly composed of hydraulic motors, control circuits, reducers and reels. In the parking state, the hoist needs to be braked by the brake; while in the working state, the hoist continuously retracts and releases heavy objects through the cable, and the brake needs to be opened.

[0003] figure 1 It is a common hoist hydraulic control circuit in the prior art. When the main valve 1a outputs pressure, the hydraulic oil enters the oil inlet and outlet of the motor 5a. At the same time, the hydraulic oil passes through the shuttle valve 4a to open the sequence valve 3a, and then passes through the pressure reducing valve. After 2a, it reac...

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