| テクニカルセッション１（テーマ：ものづくりにおけるプロセスイノベーション）
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| 講演「難削材の自由曲面加工におけるびびり振動問題」 |
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Y. アルティンタス教授（ブリティッシュコロムビア大学、カナダ） |
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Chatter vibrations occur due to interaction between the dynamic
deformations of the entire machine projected at the tool tip
and metal cutting process which is influenced by material properties,
tool geometry and cutting conditions. The magnitude of the cutting
forces increase proportionally with the material hardness, depth
of cut, feed rate and sometimes with the cutting speed. The
direction of the cutting forces depend on the tool geometry,
part features and direction of feed along the tool path. The
cutting forces excite the structural dynamics of the machine
causing vibrations between the tool and workpiece. The vibrations
change the thickness of the chip, which starts oscillating close
to one of the natural frequencies of the machine tool. The magnitude
of the vibrations increase proportional to decrease in the stiffness
and damping of the machine tool structure. If the depth of cut
and spindle speed is not selected correctly, the vibrations
grow and chatter occurs, which lead to poor surface finish,
overloading of the tool and spindle with excessive dynamic forces.
This paper and talk will present the mechanism of chatter, parameters
which influence it and methods of predicting and avoiding chatter
vibrations in practice |
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