Automotive lamp shell injection molded parts

Automotive lamp shell injection molded parts

Use the coordinate measuring machine to study the CMM/CAD technology of the injection molded parts of the automobile lamp housing, and design a set of methods to improve the inspection accuracy, inspection speed and fast reverse modeling. The specific research work is as follows:

1. Plan the CMM measurement path of the lamp housing. Introducing the theory of multi-color set, the lamp shell is divided into 54 features according to plane, circle, cylinder, and plane. The probe type, measurement direction, and safety plane are used as the personal color of the lamp shell feature, and the logical addition of the personal color is performed. Establish a unified color model for the feature set to be tested. The minimum spanning tree kruskal algorithm is used to calculate the shortest measurement path for the surface characteristics of the injection molded parts of the automobile lamp housing. In the process of measurement path planning, the safety plane, moving points and probe retreat distance are designed to achieve the purpose of measurement path collision and avoidance.
2. Use the orthogonal test method combined with the CMM probe calibration to study the error factors that affect the measurement accuracy. Use the out-of-tolerance result of the CMM probe verification as the test index of the orthogonal experiment. According to the ambient temperature, the length of the measuring rod, the diameter of the measuring ball, and the measuring speed, the 4-factor 4-level orthogonal test is designed, and the range analysis is used. The evaluation method optimizes the control error factors, and calculates the order of the size of the error factors: ambient temperature> stylus diameter> extension rod length> touch speed. Therefore, it is necessary to control the ambient temperature of the measurement room in daily experiments to ensure a constant temperature of 20°C.
3. Use the theory of multi-color collection to divide the collection color results of injection molded parts of automobile lamp shells, and study the manual sampling of countless mold CMMs of automobile lamp lamp shells. Sampling of lamp housing characteristic data. Use the data sampled for the first time to carry out the first CAD reverse modeling of the lamp housing.

4. Using the first CAD reverse modeling digital model, carry out the second sampling of automobile lamp shell injection parts, establish the best-fitting coordinate system, and optimize the sampling strategy. Using the second CMM sampling data, the method to improve the modeling accuracy is studied, and the reverse modeling of the lamp housing is optimized. Use the shortest measurement path planned by the coordinate measuring machine to verify and evaluate the modeling results after CAD optimization.