tolerance modeling method based on a peripheral Bezier parameter space

Abstract

The invention discloses a tolerance modeling method based on a peripheral Bezier parameter space. An ideal workpiece is embedded into a peripheral Bezier parameter space, the workpiece is expressed through control points of the peripheral parameter space, the positions of the control points are changed, the peripheral parameter space is changed, and therefore the size, the shape and the position of the embedded workpiece are indirectly changed. By establishing a mathematical model between the offset of the peripheral space control point and the workpiece tolerance range, the offset of the peripheral control point can be solved within a given tolerance range, and finally a tolerance representation and statistical tolerance model under the worst condition is obtained. According to the method, the assembly property under the actual working condition can be judged according to the calculation result, the tolerance design result is verified and checked, and then product performance changesunder different assembly design tolerances can be predicted and judged; The modeling mode is not only suitable for dimensional tolerance modeling, but also suitable for form and location tolerance modeling; And meanwhile, the method is suitable for tolerance analysis and integration under the worst condition, and is also suitable for tolerance analysis and design under statistical significance.

Description

technical field [0001] The invention relates to the technical field of mechanical tolerance digitalization, in particular to a tolerance modeling method based on peripheral Bezier parameter space. Background technique [0002] Tolerancing is an important part of part design and assembly, and it plays a key role in product quality and manufacturing cost. [0003] At present, many universities and research institutes have conducted research on tolerances, which are listed below. [0004] Zhang Weimin of Tongji University and others applied for a patent with the publication number CN101710355B. The title of the invention is "actual working condition tolerance modeling method based on Jacobian screw". Changes, so as to obtain the assembly tolerance model under the actual working condition. Since the screw model can only represent rigid body motion and cannot represent complex deformation, the patented method is slightly simpler for shape tolerance modeling. [0005] Zhang Kai...

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Problems solved by technology

[0009] To sum up, most of the existing methods focus on the modeling of dimensional chain tolerances, and seldom dabble in shape and position tolerances. Even in the patent with publication number CN1010355A, although in the part tolerance modeling, the part feature elements The deviation is simplified to a screw representation, however, it is still difficult to deal with complex surfaces, and the lack of consideration of shape tolerance restricts the integration research of tolerance technology

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