# US 10,766,113 B2 · Machine tool

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- Number: US 10,766,113 B2
- Document ID: US10766113B2
- Status: Granted
- Kind: B2
- Application number: 16/060,285
- Filed: 2015-12-11
- Published: 2018-12-13
- Granted: 2020-09-08
- Earliest claimed: 2015-12-11
- Assignees: Makino Milling Machine Co., Ltd.
- Applicants: Makino Milling Machine Co., Ltd.
- Inventors: Sakyo Matsushita
- Web page: https://patentgrep.com/patent/US10766113B2

## CPC

- B23Q 15/12: Adaptive control, i.e. adjusting itself to have a performance which is optimum according to a preassigned criterion
- B23Q 11/0032: {Arrangements for preventing or isolating vibrations in parts of the machine (B23B29/022, B23D47/005 take precedence; means for damping or suppressing vibrations, in general F16F)}
- B23Q 17/0971: {by measuring mechanical vibrations of parts of the machine (arrangements for measuring vibrations B23Q17/12)}
- B23Q 17/12: for indicating or measuring vibration
- G01H 1/003: {of rotating machines (G01H1/10 takes precedence)}
- G01H 1/06: Frequency
- G05B 19/18: Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of program data in numerical form (G05B19/418 takes precedence)
- G05B 19/406: characterised by monitoring or safety (G05B19/19 takes precedence)
- G05B 2219/37434: Measuring vibration of machine or workpiece or tool
- G05B 2219/37634: By measuring vibration
- B23Q: DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING (tools of the kind used in lathes or boring machines B23B27/00); MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
- G01H: MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G)

## Abstract

A machine tool is configured so that: a first frequency band comprising the main shaft characteristic vibration frequency and a second frequency band comprising the mechanical structure characteristic vibration frequency are set; thresholds are stored for each of the set frequency bands; vibration components are extracted for each of the frequency bands from the output of a vibration sensor; and when the vibration amplitude exceeds a threshold in either of the frequency bands, an alarm is sounded.

## Claims

### Claim 1

A machine tool including a vibration sensor configured to measure vibration and detecting abnormal vibrations during machining, the machine tool comprising:
a frequency band setting unit configured to set, within a range of frequencies that can be measured by the vibration sensor, a first frequency band including a natural frequency of a spindle system, and a second frequency band including a natural frequency of a movement system, and a third frequency band including a natural frequency of a fixed system of a feed axis device, and
a filter unit configured to extract vibration components in the first, second and third frequency bands from an output from the vibration sensor.

### Claim 2 (depends on 1)

The machine tool of claim 1, further including a storage unit configured to store a threshold value for each frequency band set by the frequency band setting unit, and
a warning unit that issues a warning when an amplitude of vibration exceeds a threshold value in any frequency band.

### Claim 3 (depends on 2)

The machine tool of claim 2, wherein the storage unit stores a plurality of different threshold values for each frequency band, and the warning unit issues a different warning for each of the plurality of different threshold values.

### Claim 4 (depends on 1)

The machine tool of claim 1, further comprising a display unit configured to graphically display amplitudes of vibrations measured by the vibration sensor in each frequency band.

### Claim 5

A machine tool including a vibration sensor configured to measure vibration and detecting abnormal vibrations during machining, the machine tool comprising:
a frequency band setting unit configured to set, within a range of frequencies that can be measured by the vibration sensor, a first frequency band including a natural frequency of a spindle system, a second frequency band including a natural frequency of a movement system, and a third frequency band including a natural frequency of a spindle rotation, and
a filter unit configured to extract vibration components in the first, second and third frequency bands from an output from the vibration sensor.