Research On Telescopic Smoothness Of Telescopic Arm Of DCT75 Truck Crane

U-shaped telescopic arm structure has been widely used in newly designed medium and heavy-duty truck cranes due to its high bending and torsion rigidity,good guiding performance and high material utilization.In the process of commissioning new products,a crane manufacturer finds that such telescopic arms will experience severe jitter when they are rapidly expanding and contracting under high-angle and no-load conditions,which seriously affects the normal operation of the crane and poses a safety hazard.In order to explore the mechanism of the occurrence of the jitter phenomenon,this paper intends to carry out research aimed at improving the telescopic smoothness of the U-shaped telescopic arm of the truck crane.The research work includes the following contents:(1)The simplified mechanical model of the two-section arm telescopic process,the simplified model of the three-section arm string expansion and the simplified vibration model of the arm body are established.The jitter mechanism of the telescopic arm is analyzed from the theoretical level.It is pointed out that the sudden change of frictional resistance is the arm shake.The main factor.(2)In order to analyze the change of frictional resistance during the telescopic extension of the DCT75 crane telescopic arm,the 3D solid finite element simulation model of the telescopic arm considering manufacturing error is established by using ANSYS parametric design language.The analysis results show that there is frictional resistance when the telescopic arm of the DCT75 crane is telescopic.The case of mutation.(3)In order to analyze the manufacturing error of the geometry of the arm body,the properties of the slider material and the influence of the slider clearance configuration on the frictional resistance,the above model is used to analyze the results,and the analysis results show the manufacturing error of the arm geometry,the properties of the slider material and The slider gap configuration is a factor that causes a sudden change in frictional resistance during the telescoping process.Based on the analysis results,a scheme to improve the sudden change of friction resistance was developed.(4)The telescopic experiment of the DCT75 truck crane is carried out.The experimental results show that the improved scheme can improve the jitter of the arm body and improve the telescopic smoothness of the telescopic arm of the truck crane.This paper provides a new idea for studying the telescopic smoothness of U-section truck crane telescopic arm,and also provides a reference for solving practical problems of similar engineering.