Mechanic Study On Contraction Process Of QY5L Truck Crane Telescopic Arm

At present,the telescopic arm of QY5 L single-cylinder pin-type crane newly developed by a company appears jitter phenomenon in the process of contraction,especially when the telescopic arm starts to recover from the full telescopic position,the jitter phenomenon is more obvious,the occurrence of jitter seriously affects the normal work of the crane,and poses a threat to the safety of operators.The thrust fluctuation of the telescopic hydraulic cylinder is closely related to the jitter phenomenon of the telescopic arm contraction process,therefore,it is of great significance to carry out the mechanical research on the contraction process of the crane telescopic arm.In this paper,the telescopic arm of QY5 L singlecylinder pin-type crane is taken as the research object,the combination of theoretical analysis and experimental analysis is used to study the mechanical process of the telescopic arm contraction process,and the solution to suppress the jitter in the telescopic arm contraction process is proposed.Firstly,through the research on the thrust model of the crane telescopic hydraulic cylinder,the influence of manufacturing error and other factors on the frictional resistance between the telescopic arm and the slider is theoretically analyzed.Secondly,in order to change the friction resistance between the telescopic arm and the slider,several different slider structures are designed to adjust the assembly gap between the slider and the telescopic arm.The numerical results of the friction resistance between the slider and the telescopic arm under different structural forms show that the friction resistance between the telescopic arm and the slider decreases obviously after the improvement of the slider structure.Then,based on the parametric design language of ANSYS software,the parameterized finite element model of the single-cylinder pin-type crane is built,and the static analysis under typical working conditions is carried out,which provides the basis for the feasibility of the slider structure improvement scheme.Finally,the experimental test of crane shrinkage jitter is carried out.The experimental results are consistent with the theoretical analysis results,it shows that the factors such as the amount of telescopic arm overlap,the speed of telescopic and the structure of slider have great influence on the jitter of telescopic arm.It is verified that the improvement scheme of slider has good restraining effect on the jitter phenomenon of telescopic arm contraction process.The research content of this paper provides a solution for restraining jitter in the process of crane telescopic arm contraction,and also provides a reference for solving similar engineering problems.