Papers by Author: Yoshihiro Kawano

Abstract: For a cutting process using a low-rigidity end mill, it is very important to be able to estimate the degree of machining error caused by the deflection of the tool. The purpose of this study is to establish a method of estimating, in real time, the machining error caused by the deflection at the cutting point of an end mill. To this end, in this research, a method for estimating the machining error caused by the deflection of the tool used for the ball-end milling of a hemispherical surface was verified by comparing the estimated and measured deflections of the tool. As a result, it was found that the machining errors in ball-end milling could be estimated from the normal force at the moment when the radial direction of the peripheral cutting edge is normal to the feed direction of the tool.

Abstract: This report describes a two-dimensional monitoring system for milling machines using small-diameter tools. Small-diameter tools are used for high-speed milling, and they are indispensable for high-quality and high-productivity manufacturing. However, tool breakage occasionally occurs, and this becomes a serious problem in automated production. This study aims to develop a system for monitoring the cutting state that can prevent tool breakage. The proposed system consists of two charge-coupled device (CCD) cameras, an image processing device, a man-machine controller (MMC), and a machining center with an open computer numeric (CNC). This monitoring system is connected to the machining center by Ethernet. It enables the precise measurement of tool deflection during high-speed milling. In an experiment, we applied this system to the end milling of a steel plate under different cutting conditions, and we examined the relationship between tool deflection and the cutting conditions. In addition, we applied this monitoring system to measure tool wear, and we examined the relationship between tool deflection and tool wear. It was found that the proposed system enabled in-process monitoring of the cutting state and tool wear.

Abstract: End mills with small diameter have found their wide application with the development of high-speed cutting. It becomes more and more important to develop effective methods to monitor and control the milling process with small end mills. In this paper, a measuring system of projection image for small end mills is introduced, and the application of the projection image to monitor the behavior of the end mill is discussed. It is found that for static state of the end mill, the measurement accuracy can be easily controlled within 1 μm. When the end mill rotates, it is not so difficult to control the accuracy within 3 μm. By using of the change in image width, the radial wear of end mill can be predicted. On the other hand, if the centre shift of the image is pre-measured, the deflection of the end mill during cutting can be predicted.