Systematic Optimization of Concurrent Design of Product and Locating Strategy by Datum Flow Chain

Abstract

Research and/or Engineering Questions/Objective. In the vehicle building, the matching of outer surface, such as front face, is most important and is increasingly concerned by customers. Many companies and researchers commit themselves in the improvement of matching quality of vehicle. Basically, it is revealed that not only product design, but also the locating strategy of fixture design play a significant role in the improvement of matching quality. However, if we want get an optimized product design and locating strategy of fixture, traditionally it’s quietly difficult because always the fixture design is carried out after the product design, and consequently is restricted by the fixed product design. It is obviously that if we want get an optimized scheme, many times lead to engineering change. So it is most valuable for us to find a systematic method for concurrent product and locating strategy design in the very early design stage, to achieve the high matching quality. Methodology. In this paper, the datum flow chain is introduced as a systematic approach in the development of concurrent design about product and locating strategy of jig fixture in the very early design stage. For instance, the structure and jig fixture design of fender and hood is taken. First, with given key characteristics, the datum flow chain is presented. Then, based on the datum flow chain, proper product and locating strategy design is carried out to bypass the maximum part variation to get a optimized dimension performance. Results. By the application of datum flow chain, we can find the preferred locating strategy immediately. To make a validation of application of datum flow chain, finally, a 2D tolerance analysis is carried out for two locating strategy, and it’s indicated that datum flow chain can make a optimized locating strategy design in the early product design stage. Limitations of this study. In this paper, the concurrent design of product and locating strategy by datum flow chain is only confined in a qualitative analysis in the very early stage. Further study can be how to carry out a quantitative analysis about the determined product and fixture design by using datum flow chain. What does the paper offer that is new in the field in comparison to other works of the author. Tolerance analysis is a powerful method to investigate whether the product and fixture design (locating scheme) meet the quality requirement, such as ADCATS, VisVSA, 3DCS. However, it is always applied in the detailed design stage, with determined structure. Meanwhile, Datum flow chain is a systematic approach about assembly design for optimizing dimensional performance, raised by Whitney, is extensively applied in many fields. However, its application in concurrent product and fixture design is fairly rare. In this paper, it is presented a method about the concurrent product and locating strategy design to get optimized matching quality in the very early design stage. Conclusion. By using DFC method, the concurrently structure design (“contacts” design) and locating strategy design can be carried out to by-pass the maximum variation (body variation). Consequently, the optimized product design and process design is realized in the very early stage to avoid time-consuming and expensive engineering change.