A hydraulic control system for a crane

Abstract

The invention discloses a hydraulic control system of a crane, and belongs to the field of control. A brake mechanism of a span winch is in a start state, and the span winch controls a lazy arm of thecrane to descend in an amplification manner. When the span winch needs to stop the descending process of the lazy arm of the crane, hydraulic oil in a rod cavity of a brake oil cylinder is pressed toflow towards a fixed differential reducing valve, a first throttling valve, a pilot operated directional control valve and an oil tank. The backflow speed of the hydraulic oil in the rod cavity of the brake oil cylinder is controllable through the fixed differential reducing valve and the first throttling valve, then the time that the pressure in the rod cavity of the brake oil cylinder is reduced till the span winch is locked by the brake mechanism is controllable, the time is the same as the time that the lazy arm of the crane gently descends by a section of distance under the inertia effect, and it is shown that when the lazy arm of the crane completes the descending motion under the inertia effect, the brake mechanism just brakes the span winch at this moment. The problems brought bytoo fast or slow braking of the brake mechanism are avoided, and the work efficiency of the crane is guaranteed.

Description

technical field [0001] The invention relates to the control field, in particular to a hydraulic control system of a crane. Background technique [0002] The boom of a large offshore crane is generally fixedly connected to the cable of the luffing winch of the crane, and the luffing winch controls the position of the boom of the crane by retracting and releasing the cable. A brake mechanism is installed on the luffing winch to lock the cables on the luffing winch when the luffing winch is not working, so as to ensure the stability of the boom position of the crane. The luffing winch and the braking mechanism on the crane are usually controlled by a hydraulic control system, which is used to control the luffing winch to retract and unwind the cables, and to control the braking mechanism to lock the luffing winch when the luffing winch is not working. cable. [0003] When the luffing winch releases the cable to make the boom of the crane increase and descend, if the release o...

AI Technical Summary

Problems solved by technology

[0003] When the luffing winch releases the cable to make the boom of the crane increase and descend, if the release of the cable is stopped suddenly, the boom of the crane will still drop slightly for a certain distance under the action of inertia, and the existing hydraulic control system of the crane cannot Better control the braking time of the luffing winch, so the brake mechanism of the hydraulic control system will brake too fast or too slow when the boom of the crane is lowered due to inertia, and the brake mechanism will brake too fast and cause The boom of the crane shakes a lot, and the brake mechanism brakes too slowly, there may be unexpected situations that cause the position of the boom of the crane to change, both of which will affect the working efficiency of the boom of the crane

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