Dynamic Response Analysis And Optimization Of Tower Crane Weighting Transducer Based On Rigid-flexible Coupling Model

The weighting transducer of tower crane is a safety device used to pick up weight signal and proof against overload.According to the actual service data,it does happen on occasion that the weighting transducer can’t collect the data.Through investigation and analysis,it is found that the wrap angle of steel wire rope,i.e.,the installation position,is one of the important factors.What’s more,the multi-pin-shaft clearance connection in the weighting transducer will produce complicated nonlinear mechanics results,thus affecting the stability and accuracy of data acquisition.Therefore,it is of great practical value to creat the rigid-flexible coupling dynamics simulation model of the weighting transducer including the flex shaft pin type load cell and to analyze the influence of the installation position and the pin-shaft joint clearance on the data acquisition,so that the optimum installation position and the assembly clearance at the joint of the pin-shaft can be determined.In light of analysis of the working principle of the weighting transducer and the geometrical relation of its installation position,this paper studies the rigid-flexible coupling dynamics simulation of the weighting transducer as well as the effect of the specific installation position on the crane boom and the pin-shaft clearance on the data acquisition.Through further optimization of the pin-shaft clearance size and the installation position interval,this paper provides reference and basis for the structure optimization of the weighting transducer and the site installation position on the tower crane.The main research contents are as follows:Firstly,for the weighting transducer,its structure and installation position on the tower crane boom are analyzed.The working principle and the detection path of lifting capacity data are studied after that.What’s more,the paper also analyzes the conversion relationship between load wire rope tension and measured voltage.Finally,this paper not only analyzes the installation position of the weighting transducer on the crane boom,and establishes the geometric model of the installation position,but also studies the calculation formula of steel wire rope wrap angle.The rigid body dynamics model of the weighting transducer with clearance is established step by step.The first step is to creat the simulation model of the weighting transducer with clearance by parameterized methods,and the second step is to creat the mechanism dynamic simulation model of hoist wire rope.The third step is to validate the rigid body dynamics simulation model by selecting the lifting working condition parameters of 2 times.The rigid-flexible coupling model with flexible shaft is established and the dynamic response analysis is carried out.Firstly,the flexible load cell model is established to replace the rigid load cell,and the rigid-flexible coupling model is established.Secondly,the deformation analysis of the sensor shaft is carried out to verify the model by comparing with the theoretical results.Finally,the effects of pin-shaft clearance of different position,pin-shaft clearance size and steel wire rope angle on the vibration characteristics,load and strain of the shaft type load cell are studied by carrying out simulation calculation.Perform optimization analysis.The first step is to optimize the clearance size of pinshaft and analyze the effect law of clearance size and clearance at different positions.The second step is to optimize the installation position,analyze the dynamic response law,and construct the fitted curve of the installation position and the strain.Thirdly,according to the optimization results and engineering practice,it is determined that the interval of the pin-shaft clearance is 0.8mm-1mm,and the installation position is 750mm-850mm from the pulley of weighting transducer to the pulley of tower cap.