Time Domain Simulation of Dynamic Corner Milling Process Considering Chatter Vibration With Finite Amplitude

A number of analysis methods for the process with chatter vibration have been proposed so far. These methods can be used to improve processes stability resulting in better production efficiency. However, the poor estimation accuracy of the phenomenon severely limits the performance of process optimization using the simulation-assisted approach. One of the causes of accuracy deterioration is the modeling error of the phenomenon accompanied by chatter vibration with finite amplitude. In this study, we developed a model that can consider the non-linear uncut chip thickness fluctuation caused by the influence of finite amplitude and the process damping due to the contact of the tool flank face against the finished workpiece surface. Furthermore, we developed a time domain simulator that implements the proposed model, and estimated the finished surface profile of the workpiece based on the results of the time domain simulation. To verify the proposed method, corner machining experiments with an end mill were conducted. Corner machining is frequently used in industrial, but it is known that chatter vibration is likely to occur. In corner machining, machine tools generate motions that accompany acceleration and deceleration. The motion of this feed drive system strongly depends on the dynamic characteristics of the machine tool and the trajectory generation algorithm, which greatly affects the emersion angle of the cutter. Therefore, we simulated the dynamic corner machining process considering the measured data of the motion trajectory of the feed drive system. The estimation result of chatter vibration in corner machining is in good agreement with the measurement result of the machining process. In addition, high-precision estimation of the machined surface profile with chatter mark has been realized.

A tool path optimization approach based on blend feature simplification for multi-cavity machining of complex parts

Blend features usually exist in the machining of complex multi-cavity parts; however, the ideal linear boundary of the cavity is shown as an arc curve at actual corner machining, which affects the accuracy of a robot’s tool feed position. Focused on this problem, this article presents an automatic tool path planning approach based on blend feature simplification. By analyzing the geometric elements of blend feature, a line segment is constructed to obtain the machining boundary, while the robot tool feed position is accurately measured. On this basis, the coordinates of a robot tool feed position are assigned to the machining element, which can be used to calculate the spatial distance between different cavities. Then, an improved genetic algorithm is applied to improve the optimization of the tool path. The automatic decision of the corresponding work steps is realized by merging and sorting the machining elements. Finally, a corresponding prototype system is presented, with the correctness and validity of the proposed approach being examined, using aircraft structural part machining as an illustrative example.

Modeling and Simulation of Ball End Milling Force for Mold Cavity Corner

In this paper, a cutting force model in ball end milling of mold cavity corner is established. Based on infinitesimal milling force model, cutting element of ball end milling cutter is treated as equal diameter end milling cutter, then determine the location of points when the micro-element participated in the cutting, and the tool-workpiece contact area and cutting range is determined. Thereby a complete milling force model in corner machining with ball end milling cutter is established.

Research on Corner Control Strategy of the WEDM

Corner machining accuracy has always been one of the important properties of WEDM. In this paper, the reasons for the corner error of the WEDM were discussed. Then the mathematical deflection model of the electrode wire was established. By experimental measurements, the kerf width and the deflection of the electrode wire were obtained. Then the corner control strategy of the WEDM was proposed. Through experiment of the Comparison of corner error between control strategy with corner control and the one without corner control, it shows that the processing accuracy was improved effectively.

Optimization of the 2 1/2 D Pocket Machining Using Multiple Tools

This work presents some contributions for optimization of the 2 ½ D pocket machining. The machining strategy considered is divided in internal machining and corners machining. The internal machining is carried through equidistant paths to the contour (offset) made by using Voronoi’s Diagram and the corner machining follows the same principle. As the Voronoi Diagram is parametric, the spaces between the paths can change. Thus, the best situation of spacing between paths can be determined to optimize the process. By using Dynamic Programming, the best combination of dimensions of the available tools can also be identified to remove the material of the pocket in smaller time.