Hoist telescopic hydraulic control system and construction machinery

Abstract

The invention relates to the field of cantilever crane telescopic control systems, and discloses a winch telescopic hydraulic control system and engineering machinery. A main oil pump (2) of the winchtelescopic hydraulic control system is selectively communicated with a first working oil path (L1) or a second working oil path (L2) through an operating valve (5) to control a cantilever crane to stretch or retract, the main oil pump (2) is connected to a feedback control oil path (L3), an on-off control valve (6) linked to the retracting operation of the operating valve in a communicating stateis arranged on the feedback control oil path, the on-off control valve has a hydraulically controlled cavity, the hydraulically controlled cavity is connected to a stroke control oil path (L4), a stroke valve is arranged on the stroke control oil path, and the stroke valve can be triggered by the cantilever crane to connect the stroke control oil path (L4) when the cantilever crane stretches outto a preset stretching position in the stretching process of the cantilever crane and the hydraulically controlled cavity communicates to the first working oil path (L1), so that the on-off control valve (6) is switched to a cut-off state, and therefore, the safety of the cantilever crane stretching out is improved.

Description

technical field [0001] The invention relates to a boom telescopic control system, in particular to a winch telescopic hydraulic control system. On this basis, the present invention also relates to a construction machine with the winch telescopic hydraulic control system. Background technique [0002] In construction machinery similar to cranes and fire trucks, it is often used to hoist the frame on the construction machinery to do telescopic movement. But, when hoisting drive frame body stretches out, must control the extending stroke of frame body, in order to avoid frame body to stretch out overtravel and cause frame body to fall off. [0003] In the existing winch drive system, the extension stroke of the frame body is often detected by electrical components, and the extension stroke of the frame body is controlled according to the detection results of the electrical components. However, when the engineering machinery where the frame body is located is powered off or is...

AI Technical Summary

Problems solved by technology

However, when the construction machinery where the frame body is located is powered off or is in a manual operation condition, the extended stroke of the winch drive frame body loses protection immediately.

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