Design of a simulation experimental platform of a multidimensional force tracking-loading simulator for a five-axis machining center

Although computer numerical control (CNC) machine tools have made substantial advancements in speed, accuracy, multiaxis linkage, composite functions, and intelligence, they still face challenges with high failure rates and poor functional retention, which hinder industry progress. In particular, five-axis machining centers excel in complex surface machining owing to their high degrees of freedom, complex structure, and high degree of technical integration, along with variable working conditions, resulting in a high failure rate. Therefore, studying the reliability of five-axis machining centers is crucial for overcoming these challenges.

This study addresses the challenges of limited loading dimensions and difficult engineering applications in the reliability testing of CNC machine tools. It presents the design of a multidimensional force tracking-loading simulator specifically for five-axis machining centers, along with the development of an experimental platform. The main body of the simulator includes a tool bearing, conical test piece, and super elastomer rubber ring. The rubber ring is attached to the surface of the conical test piece. As the tool bearing rolls and squeezes the rubber ring, its deformation simulates the cutting force that would be applied during the machining process of the conical specimen by a five-axis machining center. In addition, the A/C-axis cradle-type vertical five-axis machining center serves as the foundation for deriving a cutting force model using chi-square coordinate transformation. A multidimensional force tracking-loading simulation experimental platform is built, and experiments are conducted. The experimental platform includes the following: the simulator, data acquisition, and data analysis tools. The simulator and Kistler force gauge are installed on the five-axis machining center table. The data acquisition system captures real-time changes in cutting force between the tool bearing and the loading device, transmitting these measurements to a computer for analysis. This study aims to examine how different spindle speeds, rubber ring thicknesses, and cutting depths affect the cutting force in the actual cutting process of the conical test piece and verify the feasibility and multidimensional loading ability of the simulator.

The study results indicate that during stable cutting, the overall cutting force decreases as the rubber ring thickness increases and increases with deep cutting depths. An imbalance in the ratio of cutting depth to rubber ring thickness can lead to data fluctuations. Optimal conditions were observed at a spindle speed of 1000 rpm with a rubber ring thickness of 3 mm, resulting in minimal fluctuations in cutting force, which is the best thickness of the rubber ring in the loading experiment.

This method effectively simulates the cutting force load of the actual cutting process with a five-axis machining center. In addition, facilitates the engineering application of the reliability loading device and provides a low-cost, recyclable loading method for reliability testing of CNC machine tools.