Abnormality detection apparatus for tool and numerical control apparatus provided with same
AssigneesYoshiaki Kakino, Mori Seiki Co., Ltd., Yasda Precision Tools K.K., Osaka Kiko Co., Ltd., Yamazaki Mazak Corporation, Mitsubishi Denki Kabushiki Kaisha
InventorsYoshiaki Kakino, Makoto Fujishima, Hisashi Otsubo, Hideo Nakagawa, Yoshinori Yamaoka, Torao Takeshita
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Abstract
An abnormality detection apparatus for a tool (11) is described for judging abnormalities of a tool by a uniformly set threshold value in relation to a cutting load even in a machining process wherein a feed rate changes every moment. The abnormalities of the tool can be judged by the uniformly set threshold value on the basis of the tool load wherefrom the feed load that fluctuates upon the feed rate has been removed.
Claims3
An abnormality detection apparatus for a tool to detect abnormalities of a tool used for machining of a machine tool comprising:
- cutting load detecting means to detect a cutting load on the basis of an electric current for driving that is output to a feed drive system of the machine tool and/or an electric current for driving that is output to a spindle drive system;
- feed load estimating means to estimate a feed load on the basis of a feed rate of the feed drive system, wherein the feed load is a load component depending on the feed rate;
- tool load detecting means to compute a tool load as a load component which depends on the tool by reducing the feed load estimated by the feed load estimating means from the cutting load detected by the cutting load detecting means;
- and
- abnormality judging means for a tool to judge whether the tool is in an abnormal condition or not on the basis of the tool load computed by the tool load detecting means.
Dependencies are inferred from the claim text.