Design And Development Of Precision Clamping Positioning And Transposition Manipulation System For Thin-wall Pipe

Currently,laser processing equipment is widely used in the processing of thin-walled slender pipes with complex profiles and morphology.The precision clamping and the manipulation device are some of the core technical problems.From the perspective of constraints,aiming at the requirements of multi-section profile centering clamping positioning,pipe feeding movment,and reduction of processing tailings,this thesis designs and develops a prototype of pipe centering clamping device and feeding system,which can adapt to the multisection shape,to meet the constraints of pipe in the processing process.The main research contents are as follows:The analysis methods of constraints and accuracy in precision machine design are summarized based on the investigation of multi-claw centering clamping device and chuck technology.Based on the positioning principle of kinematic precise constraints,the degree of freedom of the object,the arrangement of the contact points,the principle of the caging,the positioning error,and the transposition manipulation method to realize the feeding operation is analyzed.The constraint principle involved in the design of the device is expounded as well.According to the clamping adaptability of circular,elliptical,and rectangular cross-section pipes,the comprehensive evaluation index is established by analyzing the clamping position layout,and the four claws orthogonal clamping mode is determined.To prevent different pipes from breaking away from the claw constraint in the process of feeding,the initial position of the claw was determined according to the caging principle.To reduce the volume of the equipment,a feeding system composed of double chuck and two-finger clamp is designed based on transposition operation,which realizes the design of pipe clamping positioning and transposition operation system.Aiming at the chuck with the function of locating the pipe,the influence of the clamping error of the claw on the attitude error of the pipe is analyzed.The mathematical model of the influence of the clamping error of the claw on the focal length of the laser head on the processing plane is established by introducing the limacon model,and the relationship between the clamping accuracy and the processing accuracy is explained.Aiming at the mechanism of the influence of two chucks on machining accuracy of the tube,the Slope-deflection equation,and the minimum potential energy method are introduced to establish the optimal solution model of the machining attitude error of the tube with coaxiality error,and the augmented Lagrange method is used to solve the drift of the tube pose error,Then,the multi-factor and multi-level orthogonal experiment method is used to clarify the design direction of each design parameter.In the finite element simulation software,the optimization direction is verified by comparing the two schemes of high contact stiffness support end single roller at the drive end and low contact stiffness support end double roller at the drive end,and the optimal constraint configuration scheme is obtained,which provides theoretical support for the prototype development.Finally,according to the above analysis results,the prototype,measurement and control system are built,and the caging function test and rotation accuracy test are carried out on the prototype,which proves the rationality of the prototype scheme.