Multi-path reversing device of lorry-mounted crane

Abstract

The invention discloses a multi-way reversing device for a truck-mounted crane, which includes an oil inlet circuit, an oil return port, and a luffing reversing valve for operating the three actions of lifting, stopping and falling back of the luffing oil cylinder. The telescopic reversing valve is used to operate the three actions of extension, stop and retraction of the telescopic cylinder, the hoisting reversing valve is used to operate the three actions of the hoist motor to rise, stop and descend, and it is used to operate the positive direction of the slewing motor The rotary reversing valve and functional module with three actions of direction, stop and reverse, the luffing reversing valve and the telescopic reversing valve are connected in parallel at both ends of the oil inlet oil circuit, the rotary reversing valve, the functional module and the oil inlet oil circuit are connected in series, and the telescopic reversing valve After the reversing valve and the functional module merge, they are connected in series with the hoisting reversing valve and the oil return port in sequence; this device realizes luffing and hoisting, luffing and rotation, telescopic and hoisting, telescopic and rotary, and rotary and hoisting, etc. Five kinds of composite actions can be realized without proportional multi-way valve, which effectively reduces the cost and improves the cost performance of the straight arm truck-mounted crane.

Description

technical field [0001] The invention relates to a multi-way reversing device for a truck-mounted crane, which belongs to the technical field of engineering machinery. Background technique [0002] The truck-mounted crane is a multi-action machine that is installed on the chassis of a car and can load and unload heavy objects within a certain range. It is fast, flexible, efficient, convenient, and integrates loading, unloading, and transportation into one. Engineering, landscaping and equipment hoisting and transportation and other fields. According to the structural form, truck-mounted cranes can be divided into straight-arm truck-mounted cranes and folding-arm truck-mounted cranes. [0003] The straight-arm truck-mounted crane can extend or retract the boom through the telescopic oil cylinder of the boom, and the wire rope drawn from the hoisting mechanism can lift the cargo. The main actions include luffing, telescopic, hoisting and turning, etc. With the advantages of w...

AI Technical Summary

Problems solved by technology

However, when the hoist moves independently, the hoist reversing valve is always in a confluence state, and the continuous large-flow oil supply will greatly increase the difficulty of the operator's manipulation. The overflow returns oil, which also increases the heat generation of the system and the energy consumption of the whole vehicle;

[0007] 2. When the hoisting compound action is performed after the slewing action, since the oil return in the middle position of the slewing directional valve is through the one-way confluence valve, the hoisting directional valve to the oil return port of the multi-way valve, the hoisting action will cause the hoisting The pressure at the oil inlet port of the reversing valve increases, which leads to a corresponding increase in the pressure of the return port of the reversing reversing valve and the oil inlet port of the reversing reversing valve

This is the phenomenon of unstable slewing speed during the compound operation of slewing first and then hoisting, which has certain potential safety hazards.

[0008] Patent CN201110169262.7 proposes a multi-way reversing valve for straight-arm truck-mounted cranes and its control method, such as figure 2 As shown, although its hoisting action has a double-speed function, the hoisting reversing valve is a five-position, eight-way structure with five working positions and eight oil ports. The road is complex, requiring special manufacturing, and there are problems such as poor adjustment performance, complex structure, poor versatility, high cost, and difficult maintenance; at the same time, it also has the phenomenon of unstable slewing speed when turning first and then hoisting compound operation

Images