Hydraulic control systems for control valves and hoisting brakes, cranes

Abstract

The invention discloses a control valve used for a winch brake, a hydraulic control system of the winch brake and a crane. The control valve comprises a valve body, a first reversing valve is integrated in the valve body, a first oil port, a second oil port and a third oil port are formed outside the valve body, the first oil port is used for being communicated with a pressure oil line with constant external pressure, the second oil port is used for being communicated with a hydraulic oil tank, and the third oil port is used for being communicated with a control oil cylinder of a first winch brake; when the first reversing valve is positioned in the first working position, the first oil port and the third oil port are communicated; and when the first reversing valve is positioned in the second working position, the second oil port and the third oil port are communicated. The special oil ports and oil passages communicated with the pressure oil line with constant external pressure are arranged in the control valve disclosed by the invention, opening and closing of the brake are controlled through the pressure oil line with constant pressure; and in the control mode, pressure for controlling opening and closing of the brake is comparatively constant, the oil line pressure cannot be influenced by loads completely, and a chattering phenomenon during winch hoisting can be effectively relieved.

Description

technical field [0001] The invention relates to the technical field of hydraulic control, in particular to a hydraulic control system for a control valve and a hoist brake, and a crane. Background technique [0002] The winch brake is a device used to realize winch braking in the winch mechanism of hoisting engineering machinery. It mainly controls its working state through a special control valve, and the opening and closing of the control valve can control the opening and closing of the brake, thereby Realize the lifting and falling of the hoisting mechanism. A hydraulic control system for a brake is described below. [0003] Please refer to figure 1 , figure 1 It is a structural principle diagram of a typical hoist brake control valve in the prior art. [0004] In the prior art, the control valve of the hoist brake includes a hydraulic control reversing valve 1', a shuttle valve 4', a pressure reducing valve 2' and a one-way valve 3', and the two oil inlets of the shu...

AI Technical Summary

Problems solved by technology

[0008] Moreover, when the hoisting mechanism performs the second hoisting operation, the hydraulic control reversing valve 1' changes direction and opens relatively quickly under the action of the load oil circuit, and the motor may not build up enough pressure in a short period of time, resulting in the lifting torque being less than The load moment generated by the heavy object leads to opening the brake, which will cause the heavy object to slide twice

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