Research On Overload Protection Control System Of Hydraulic Static Pile Driver Crane

The pile driver crane is an important part of the hydraulic static pile driver. The overload of the crane will reduce its operating life and even break it off. So, this paper have studied the overload protection control system of the piling driver crane.Firstly, on the basis of analyzing the overload condition of the pile driver crane, the overall design scheme of the overload protection control system is proposed. Through acquisition parameters such as luffing cylinder working oil pressure and elevation angle of the crane jib, the lifting capacity of the crane can be got and whether it is overload or not will be judged. Using the proportional pressure reducing valve to control the inlet oil pressure of the winding motor, and in turn, control the hoist lifting force. With the use of proportional directional control valve to regulate the range cylinder to achieve the control of the boom elevation angle, so as to realize the crane overload protection.Secondly, according to the overall scheme of the overload protection control system, the hydraulic system and the electric control system have been designed. This paper have analyzed the overload situations of the various working conditions and its protection control strategy as well as control parameters. The core of the electronic control system is the PLC programmable controller, and LCD screen with touch function is adopted to accomplish the development of human-computer interaction interface.Thirdly, the mathematical modeling and simulation analysis is carried out on the luffing system of the crane. The luffing system mathematical model based on bond graph theory is established. Then simulation analysis of the crane load falling over capacity condition has been carried out with the union simulation of AMESim and Motion. It can get the conclusion that the optimal closing time is0.2s which have taken braking stability and rapidity of the proportional directional valve into account. As a result, the ahead setting value of the crane jib brake position to ensure precise can be got.Finally, the luffing system crane load falling over capacity has been studied in the experimental study. Large experiment platform of the hydraulic static pile driver has been set. The experiment results verify the feasibility of overload protection control system design and the correctness of the luffing system simulation model as well as its solving results.In conclusion, this research provides theoretical supports and experimental basis of the pile driver crane overload protection control. It has a certain theoretical significance and practical value for its application in the engineering practice.