On the dependence of static flat seal efficiency to surface defects

Tool deflection of end mills caused by cutting forces has a great effect on the machining quality and efficiency. Cylindrical cantilever beam model with 80 % of tool radius is generally used to predict the tool deflection roughly. But that ignored the complex geometrical structure of end mills, which is manufactured with a set of grinding operations. In this study, the geometrical model of end mill is developed based on the CAD/CAM integration via modeling its grinding processes. Using the developed CAD model, the cutting coefficients and distributed cutting forces along the tool axis are obtained via finite element analysis of cutting simulation. Besides, the moment of inertia along the tool axis is also precisely measured based on the CAD model. Finally, with the measured inertia and distributed cutting forces, the tool defection can be predicted accurately with the unit loading algorithm for the cantilever beam. This study provides an accurate approach to predicting tool deflection of end mills based on the CAD/CAM/CAE integration.

A new CAD/CAM/CAE integration approach to predicting tool deflection of end mills

This paper presents a model-based approach for monitoring of shape deviations for milling operations. In order to detect occurring shape deviations of the machined workpiece during the milling process, different kinds of process models are presented and discussed for their application on manufacturing quality monitoring. Thereby, a model-based system was presented for the monitoring of shape deviations based on measured cutting forces. For the transformation of cutting forces into shape deviations, a tool deflection model and material removal model were designed and applied to a monitoring system. The presented model-based monitoring approach delivers accurate quality information, like geometric shape deviations, which can be monitored against geometric tolerances, providing a quality monitoring of manufacturing processes. The reconstruction of shape deviations from measured cutting forces is verified experimentally by comparing measured and reconstructed shape contours.

A model-based approach for monitoring of shape deviations in peripheral milling

Milling is used widely as an efficient machining process in a variety of industrial applications, such as the complex surface machining and removing large amounts of material. Flutes make up the main part of the solid end-mill, which can significantly affect the tool’s life and machining quality in milling processes. The traditional method for end-mill flutes design is using try-errors based on cutting experiments with various flute parameters which is time- and resources-consuming. Hence, modeling the flutes of end-mill and simulating the cutting processes are crucial to improve the efficiency of end-mill design. Generally, in industry, the flutes are ground by CNC grinding machines via setting the position and orientation of grinding wheel to guarantee the designed flute parameters including rake angle, relief angle, flute angle and core radius. However, in previous researches, the designed flute profile was ground via building a specific grinding wheel with a free-form profile in in the grinding processes. And the free-form grinding wheel will greatly increase the manufacturing cost, which is too complicated to implement in practice. In this research, the flute-grinding processes were developed with standard grinding wheel via 2-axis or 5-axis CNC grinding operations. 
For the 2-axis CNC flute-grinding processes, the flute was modelled via calculating the contact line between the grinding wheel and cutters. The flute parameters in terms of the dimension and configuration of grinding wheel were expressed explicitly, which can be used to planning the CNC programming. 
For the 5-axis CNC flute-grinding processes, the flute was obtained with a cylinder grinding wheel via setting the wheel’s position and orientation rather than dressing the dimension of grinding wheel. In this processes, optimization method was used to determine the wheel’s position and orientation and evaluating the machined flute parameters. Beside, based on the proposed flute model, various conditions for grinding wheel’s setting were discussed to avoid interference of flute profile.
A free-form flute profile is consequently generated in its grinding processes. However, in the end-mill design, the flute profile is simplified with some arcs and lines to approximate the CAD model of end-mills, which would introduce errors in the simulation of cutting processes. Based on the proposed flute-grinding methods, a solid flute CAD model was built and a CAD/CAM/CAE integration approach for the end-mill was carried out to predict the cutting forces and tool deflection. And also, the prediction results with various methods are verified to demonstrate the advantage of proposed approach. This work lays a foundation of integration of CAD/CAM/CAE for the end-mill design and would benefit the industry efficiently.

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A new CAD/CAM/CAE integration approach to modelling flutes of solid end-mills

In peripheral milling with great axial engagements, the tool deflections generate some geometrical defects on the machined surface. This article present a prediction method of these defects which is applicable on every ruled surface. The cutting forces are estimate with the cutting pressure notion. The parameters of the tool/workpiece material couple are identified by a test part. The prediction of the tool deflections requires controlling the tool immersion angle for each angular position of the tool. The deflections can be significant. An original procedure which is based on an engagement cards avoids an iterative calculation of the radial engagement. The experimental checking of the method of prediction is presented in a test.

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B. Anselmetti

Papers

A prediction of the machining defects in flank milling