Development And Precision Design Of 6-dof Lateral Assembly Intelligent Equipment

In industrial assembly,most of the manual assembly methods are currently used for the operation requirements of large weight,high positioning accuracy,narrow assembly space,small and medium batches,and loading from the side.This method has the safety problems of low efficiency,high labor intensity,and easy to bump parts.There is basically no automated and intelligent assembly equipment suitable for the above working conditions.In view of this situation,this paper proposes a prototype scheme of six-degree-of-freedom lateral intelligent assembly equipment.Combined with the assembly process requirements of the EMU ventilation fan,a six-degree-of-freedom lateral assembly automation platform is designed.In order to solve the accuracy evaluation and system accuracy design problems of lateral intelligent assembly equipment with six degrees of freedom,the error analysis and sensitivity analysis of each motion unit and assembly system are carried out,and the error evaluation method is given based on the error analysis results,and the tolerance allocation process of the accuracy design of each motion unit is given based on the sensitivity analysis results.The main research contents of this paper are as follows:(1)This paper proposes a prototype scheme for six-degree-of-freedom lateral intelligent assembly equipment;According to the assembly technical requirements,the assembly process is first formulated;On this basis,the equipment principle scheme combining intelligent pose adjustment and numerical control feeding is proposed.(2)Based on the equipment prototype,establish a systematic error model;The error sources and error distribution laws of each motion unit were discussed.The many-body kinematics theory is used to give an error analysis algorithm for each motion unit and the entire assembly system.(3)Based on the systematic error model,the error sensitivity model is established,and the normalization processing method is used to give the calculation method of the error sensitivity coefficient of the error term,and the sensitivity law of each error term is analyzed,and the tolerance distribution principle is given.(4)Combined with the assembly process requirements of the ventilation fan of the EMU,a six-degree-of-freedom lateral assembly platform is designed;(5)For the above platform,the geometric error caused by manufacturing accuracy is preset,the stiffness analysis of the main parts and the whole machine structure is carried out by the finite element method,and the deformation error caused by the force is solved;The error terms are substituted into the systematic error model for error calculation,and the error value of each motion unit is obtained.Compared with the design requirements,the sensitivity analysis of the unqualified motion unit is carried out,the error term with high sensitivity is selected to re-assign the tolerance,and finally the design tolerance that meets the accuracy requirements is given.The above examples verify the correctness of the error analysis algorithm,the calculation method of error sensitivity coefficient and the tolerance allocation principle.