Method of obtaining assembly error for actual working conditions

Abstract

The invention belongs to the field of mechanical manufacturing product assembly error modeling and discloses an assembly error acquisition method meeting actual working conditions. The method comprises the steps that (1) an assembly error spinor model based on a corrected Jacobian spinor model is established; (2) discretization is performed on part surfaces; (3) finite element software is utilizedto load a temperature field and add a stress field load, and part surface deformation is obtained; (4) the part surface deformation meeting the actual working conditions is obtained; and (5) after part surface node deformation meeting the actual working conditions is obtained, subtraction is performed on node coordinate deformation corresponding to upper contact surfaces and lower contact surfaces of combination surfaces, and then surface true assembly errors meeting the actual working conditions can be obtained. Through the method, clearance between corresponding nodes of matching surfaces can be predicted quite precisely, influences of the actual working conditions on the assembly errors are fully considered, and assembly error prediction precision is greatly improved.

Description

technical field [0001] The invention belongs to the field of assembly error modeling of mechanical manufacturing products, and more specifically relates to an assembly error acquisition method oriented to actual working conditions. Background technique [0002] Under complex working conditions, complex mechanical products are easily affected by temperature, centrifugal force, gravity, etc. during the work of the whole machine and parts, resulting in a large difference between the corresponding assembly accuracy and the theoretical prediction value, thus affecting the mechanical service performance and service of the whole machine life. Therefore, it is necessary to introduce the theory and method of assembly error construction under actual working conditions to predict the impact of actual working conditions on the assembly accuracy of the system end, and reasonably determine the accuracy of parts, otherwise it will be difficult to meet the performance requirements of the pr...

AI Technical Summary

Problems solved by technology

[0002] Under complex working conditions, complex mechanical products are easily affected by temperature, centrifugal force, gravity, etc. during the work of the whole machine and parts, resulting in a large difference between the corresponding assembly accuracy and the theoretical prediction value, thus affecting the mechanical service performance and service of the whole machine life

Therefore, it is necessary to introduce the theory and method of assembly error construction under actual working conditions to predict the impact of actual working conditions on the assembly accuracy of the system end, and reasonably determine the accuracy of parts, otherwise it will be difficult to meet the performance requirements of the product

[0003] In recent years, scholars at home and abroad have done a lot of research in the field of tolerance modeling and achieved some research results. However, when analyzing the tolerance of the 3D model of the product, they ignore the actual working environment of the product (such as the product bears various loads and temperature change, etc.), so that the analysis and prediction results are quite different from the actual situation.

The traditional assembly error analysis and modeling method is mainly to establish a screw expression such as a screw model for the variation range of the surface of the rigid part within the tolerance range, as described in the book "Theory and practice of 3-D tolerance for assembly" Introduced methods, these rarely take into account the local deformation of the component surface in the actual working conditions

However, most of the current methods considering the thermal and force deformation of parts only consider the maximum deformation, and cannot accurately simulate the deformation of each point on the surface of the part, especially when calculating the gap between two mating planes, it is impossible to accurately calculate the deformation of the two planes. The corresponding gap between each point

The requested result is too simple and not precise enough

Images