复杂发动机关键机构的公差分析和优化

分析了公差对复杂发动机性能的影响，提出了针对复杂产品的公差分析和优化方法，综合考虑了各零件公差值大小、公差分布位置和零件误差积累对产品性能的影响，并根据公差分析结果和零件的加工成本等综合因素对零件公差进行优化。定义了具有公差信息的3维模型，开发了通用计算机辅助设计模型到公差模型的数据接口，给出了复杂产品公差分析和公差优化的一般步骤。最后，使用该方法对某型发动机曲柄连杆机构和活塞机构进行了公差分析和优化，并在实际产品开发中得到了验证。

Tolerance analysis & tolerance optimization of complex diesel engine key structures

Influence of tolerance factor on the complex engine performance was analyzed,then a new tolerance analysis and optimization method for complex product was proposed. The method synthesized effects such as tolerance size, tolerance location and component error accumulation on the product performance. Tolerance was then optimized based on the result of tolerance analysis and processing cost of different parts. With this method,3D model with tolerance information was also defined, and data interface from general three--dimensional CAD models to tolerance models was developed. General steps of tolerance analysis and tolerance optimization were provided. To verify the effectiveness of the approach, connecting rod structure and piston structure in diesel engine were tested.