US 2006/0142893 A1Published application

Tool damage/abnormality detecting device

AssigneeFanuc Corporation

InventorsKuniharu Yasugi, Susumu Maekawa

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Abstract

A tool damage/abnormality detecting device capable of easily appropriately setting an allowable range for a value of comparison between a present value and a near past average for indexes indicative of loads on a tool. A machining cycle counter index i is adjusted to i=0, machining is performed as the loads are detected in a given period, and indexes H(i) (area S of load values, absolute value (G−) of a maximum inclination between two points obtained during a decrease of loads, etc.) are acquired for n number of cycles. Thereafter, the indexes and values of comparison between the index value for a present cycle and the indexes for the n number of cycles are acquired. A first comparison value can be used for initial value setting for threshold values. If any of the comparison values is deviated from the allowable range, the threshold values are updated so that the allowable range extends, and an update history is saved. If damage/abnormality is observed visually or in any other manner, a threshold value update discontinue command is inputted, machining is stopped after completion of the cycle concerned, and update values for the latest threshold value are collected to be used as set threshold values.

Claims18

Dependent claims

A detecting device for determining tool defect in which indexes, each index indicative of a load exerted on a tool for machining a workpiece, are acquired for a plurality of machining cycles, an index acquired in a present machining cycle is compared with an average of indexes acquired in machining cycles preceding the present machining cycle to acquire a comparison value indicative of a result of the comparison in each machining cycle, and determining damage and/or abnormality of the tool is when the comparison value deviates from an allowable range defined by set values of thresholds, said detecting device comprising means for determining the set values of the thresholds, including:

detecting means for detecting the indexes for a plurality of machining cycles;
comparing means for comparing an index in a selected machining cycle with an average of indexes for a plurality of machining cycles preceding the selected machining cycle to acquire comparison value indicative of a result of the comparison;
first storage means for storing values of the thresholds;
writing means for writing initial values of the thresholds in said first storage means;
updating means for updating the stored values of the thresholds to revised values according to a comparison value that deviates from an allowable range defined by the stored values of the thresholds when the comparison value acquired in the selected machining cycle deviates from the allowable range;
means for discontinuing the updating of the stored values of the thresholds in response to a command to discontinue the updating of the thresholds;
and
determining means for determining the set values of the thresholds based on the stored values of the thresholds when the update of the values of the thresholds is discontinued.

5 more elements

detecting means for detecting the indexes for a plurality of machining cycles;
comparing means for comparing an index in a selected machining cycle with an average of indexes for a plurality of machining cycles preceding the selected machining cycle to acquire a comparison value indicative of a result of the comparison;
first storage means for storing values of the thresholds;
writing means for writing initial values of the thresholds in said first storage means;
updating means for updating the stored values of the thresholds to revised values according to a comparison value that deviates from an allowable range defined by the stored values of the thresholds when the comparison value acquired in the selected machining cycle deviates from the allowable range;
second storage means for storing a threshold history containing at least some of the values of the thresholds stored in said first storage means prior to the latest updating;
means for discontinuing the updating of the values of the thresholds in response to a command to discontinue the updating of the thresholds;
and
determining means for determining the set values of the thresholds based on the values of the thresholds stored in said second storage means when the update of the values of the thresholds is discontinued.

6 more elements

A detecting device for determining tool defect in which indexes, each index indicative of a load exerted on a tool for machining a workpiece, are acquired for a plurality of machining cycles, an index acquired in a present machining cycle is compared with an average of indexes acquired in machining cycles preceding the present machining cycle to acquire a comparison value indicative of a result of the comparison in each machining cycle, and determining damage and/or abnormality of the tool when the comparison value deviates from an allowable range defined by set values of thresholds, said detecting device comprising means for determining the set values of the thresholds, including:

detecting means for detecting the indexes for a plurality of machining cycles;
comparing means for comparing an index in a selected machining cycle with an average of indexes for a plurality of machining cycles preceding the selected machining cycle to acquire a comparison value indicative of a result of the comparison;
first storage means for storing values of the thresholds;
writing means for writing initial values of the thresholds in said first storage means;
updating means for updating the stored values of the thresholds to values according to a comparison value that deviates from an allowable range defined by the stored values of the thresholds when the comparison value acquired in the selected machining cycle deviates from the allowable range;
second storage means for storing a threshold history containing at least some of the values of the thresholds stored in said first storage means prior to the latest updating;
means for discontinuing the updating of the stored values of the thresholds in response to a command to discontinue the updating of the thresholds;
and
determining means for determining the set values of the thresholds based on the threshold history stored in said second storage means and the values of the thresholds stored in said first storage means when the update of the values of the thresholds is discontinued.

6 more elements

Dependencies are inferred from the claim text.