A Hydraulically Controlled Moment Limiting System of a Knee Arm Truck Mounted Crane

Abstract

The invention discloses a hydraulic control moment restriction system of a folding arm lorry-mounted crane. A first amplitude variation control group, a second amplitude variation control group and a stretching control group are respectively communicated with a unidirectional balance valve, a first bidirectional balance valve and a second bidirectional balance valve which are respectively communicated with a first amplitude variation oil cylinder, a second amplitude variation oil cylinder and a stretching oil cylinder; three unload oil openings of a moment restriction valve are respectively communicated with a first amplitude variation oil cylinder rod cavity, a second amplitude variation oil cylinder rodless cavity and a stretching oil cylinder rodless cavity via the unidirectional balance valve, the first bidirectional balance valve and the second bidirectional balance valve. The hydraulic control moment restriction system of the folding arm lorry-mounted crane has the beneficial effects that the moment restriction valve adopts hydraulic control without a controller and a sensor, and the system is simple, and the cost is low; an anti-explosion valve can be locked after cartridge ignition so as to prevent an oil cylinder from stalling and falling off and guarantee the safety performance; the force limited state is forcefully relieved so as to achieve emergency operation.

Description

technical field [0001] The invention relates to a moment limiting system, in particular to a hydraulically controlled moment limiting system for a knuckle-arm truck-mounted crane. Background technique [0002] In recent years, with the development of market and technology, the lifting capacity of truck-mounted cranes has been continuously improved, and the application of knuckle-arm cranes in our country is increasing day by day, and the requirements for their operation safety are also increasing. The function of the torque limiting system is to limit the operating torque and play the role of safety protection. Therefore, the moment limiting system, as the main safety protection system of the truck-mounted crane, has gradually become the research focus of the truck-mounted crane. [0003] In the prior art, a lot of explanations have been made on the torque limiting device of cranes. For example, in patents CN102653380A and CN201458599U, a torque limiting system including a ...

AI Technical Summary

Problems solved by technology

However, the existing technology basically uses sensors to collect signals, and then the controller performs torque calculation and judgment, and finally realizes torque limitation by hydraulic valve locks to perform action limitation, which has complex systems, large number of components, high cost and low reliability And other issues

[0004] In view of the current market status of my country's knuckle-arm truck-mounted cranes with low electrification, manual operation, strict cost control and low safety awareness of users, it is necessary to develop a high-safety, high-reliability and low-cost torque limiting system

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