Assembly Error-mating Measurement and Compensation Method for Machining Production Line

Better production efficiency for high yield rate and low manufacturing cost is the fundamental competitiveness that companies always pursue. When producing a matching part for good mating with its counterpart (assembly part), good matching accuracy between the matching part and assembly part is highly required. The matching errors are influenced by not only the errors of the matching part but also the errors of the assembly part. Because the errors of an assembly part could be different from others, it is very difficult to have very good mating accuracy, if the manufacturing of a matching part does not take the actual errors of the assembly into account. Furthermore, it will need additional off-line assembly mating tests to find a good mating pair. This study proposes an error-matching compensation method to solve the not-good-mating problem for manufacturing assembly modules with good matching accuracy. In this method, the actual errors of an assembly part are directly in-line measured and used to compensate the machining process of a matching part so that a dedicated part with the good mating condition can be on-line made for the error-measured assembly part. In addition to having better matching accuracy, this method also provides advantages of high production efficiency and cost saving, because it will not need the off-line mating test to find good mating pairs. This method also includes a function of in-line auto-generation of error compensation NC programs to support continuous production. In this study, error analysis of two mating types (planar mating and triangle mating) were explored and discussed. The Human-Machine Interface was built with the use of C# language. Finally, machining experiments with in-line measurements were conducted to verify the proposed method. The experimental results have shown the feasibility and effectiveness of the proposed method.