US4559600A
Expired / Lapsed
US
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Monitoring machine tool conditions by measuring a force component and a vibration component at a fundamental natural frequency
Assignee: Battelle Memorial Institute Inc
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Filing: 1983-02-28
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Granted: 1985-12-17
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Expires: 2003-02-28
Abstract
Abstract Methods and apparatus for monitoring, during machining of a workpiece (30,30'), the wear condition of a cutting tool (31,31') having its cutting portion in a structure (32,32') that is held by substantially more massive means (33,33'). A dynamometer (35,35') and filter (36) measure the component of the dynamic force exerted between the tool (31,31') and the workpiece (30,30') approximately in the direction (A,A') normal to the primary cutting edge (34,34') of the tool (31,31') and to the main cutting velocity (V,V') at approximately the fundamental natural frequency of the held structure (32,32') in the same normal direction (A,A'). An accelerometer (37,37'), filter (38), and integrators (39) measure the component of vibration in the tool (31,31') approximately in the same normal direction (A,A') at approximately the same frequency. Data processing equipment (41,42,43) computes the value of a wear indicative function of the ratio of the measured force component to the measured vibration component, and provides a display, adjustment, or other selected type of response (44) thereto. The computed value of the function typically indicates the amount of wear (FW) on the flank of the primary and secondary cutting edges (34,34') of the tool (31,31') during turning, milling, or drilling.
Inventors
- 👤 Surendra B. Rao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:25
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/416; G05B19/4163; G05B2219/00; G05B2219/30; G05B2219/37; G05B2219/37357; G05B2219/37434; G05B2219/45; G05B2219/45136; Y; Y10; Y10T; Y10T408/00; Y10T408/16
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
190 words
A method for monitoring, during machining of a workpiece, the wear condition of a cutting tool having a cutting portion in a structure that is held by substantially more massive means, comprising measuring the component of the dynamic force exerted between the tool and the workpiece approximately in the direction normal to the primary cutting edge of the tool and to the main cutting velocity at approximately the fundamental natural frequency of the held structure in the same normal direction, measuring the component of vibration in the tool approximately in the same normal direction at approximtely the same frequency, computing the value of a predetermined wear indicative function of the ratio of the measured force component to the measured vibration component, and providing a predetermined type of response to the computed value of the function comprising at least one of the following operations, (a) adjusting cutting conditions to control the rate of wear, (b) adjusting the position of the tool relative to the workpiece to compensate for recession in the cutting portion of the tool, (c) replacing the tool when the wear on a cutting portion exceeds a selected limit.
Claim 2
Independent Claim
190 words
A method for monitoring, during machining of a workpiece, the wear condition of a cutting tool having a cutting portion in a structure that is held by substantially more massive means, comprising measuring the component of the dynamic force exerted between the tool and the workpiece approximately in the direction normal to the primary cutting edge of the tool and to the main cutting velocity at approximately the fundamental natural frequency of the held structure in the same normal direction, measuring the component of vibration in the tool approximately in the same normal direction at approximtely the same frequency, computing the value of a predetermined wear indicative function of the ratio of the measured force component to the measured vibration component, and providing a predetermined type of response to the computed value of the function comprising at least one of the following operations, (a) adjusting cutting conditions to control the rate of wear, (b) adjusting the position of the tool relative to the workpiece to compensate for recession in the cutting portion of the tool, (c) replacing the tool when the wear on a cutting portion exceeds a selected limit.
Claim 3
Dependent Claim
33 words
A method as in claim 1, wherein the machining comprises turning, as on a lathe, and the normal component measuring direction is the direction in which the tool is fed along the workpiece.
Claim 4
Dependent Claim
39 words
A method as in claim 1, wherein the machining comprises milling or drilling with a rotating tool, and the normal component measuring direction is perpendicular to the axis of rotation and to the main cutting edges of the tool.
Claim 5
Dependent Claim
34 words
A method as in claim 1, wherein the ratio comprises the root mean square value of the force component divided by the root mean square value of the vibration component during a predetermined time.
Claim 6
Dependent Claim
42 words
A method as in claim 1, wherein the tool has primary and secondary cutting edges, each having a flank, and the computing step comprises computing the amount of wear on the flank of the primary and secondary cutting edges of the tool.
Claim 7
Dependent Claim
23 words
A method as in claim 5, wherein the response providing step comprises providing a visual display indicative of the computed amount of wear.
Claim 8
Dependent Claim
23 words
A method as in claim 5, wherein the response providing step comprises automatically adjusting the cutting conditions to control the rate of wear.
Claim 9
Dependent Claim
35 words
A method as in claim 5, wherein the response providing step comprises automatically adjusting the position of the tool relative to the workpiece to compensate for the recession of the cutting edges of the tool.
Claim 10
Dependent Claim
26 words
A method as in claim 5, wherein the response providing step comprises automatically replacing the tool when the wear on the flank exceeds a selected limit.
Claim 11
Dependent Claim
200 words
Apparatus for monitoring, during machining of a workpiece, the wear condition of a cutting tool having a cutting portion in a structure that is held by substantially more massive means, comprising means for measuring the component of the dynamic force exerted between the tool and the workpiece approximately in the direction normal to the primary cutting edge of the tool and to the main cutting velocity at approximately the fundamental natural frequency of the held structure in the same normal direction, means for measuring the component of vibration in the tool approximtely in the same normal direction at approximately the same frequency, means for computing the value of a predetermined wear indicative function of the ratio of the measured force component to the measured vibration component, and means for providing a predetermined type of response to the computed value of the function comprising means for providing at least one of the following operations, (a) adjusting cutting conditions to control the rate of wear, (b) adjusting the position of the tool relative to the workpiece to compensate for recession in the cutting portion of the tool, (c) replacing the tool when the wear on a cutting portion exceeds a selected limit.
Claim 12
Dependent Claim
200 words
Apparatus for monitoring, during machining of a workpiece, the wear condition of a cutting tool having a cutting portion in a structure that is held by substantially more massive means, comprising means for measuring the component of the dynamic force exerted between the tool and the workpiece approximately in the direction normal to the primary cutting edge of the tool and to the main cutting velocity at approximately the fundamental natural frequency of the held structure in the same normal direction, means for measuring the component of vibration in the tool approximtely in the same normal direction at approximately the same frequency, means for computing the value of a predetermined wear indicative function of the ratio of the measured force component to the measured vibration component, and means for providing a predetermined type of response to the computed value of the function comprising means for providing at least one of the following operations, (a) adjusting cutting conditions to control the rate of wear, (b) adjusting the position of the tool relative to the workpiece to compensate for recession in the cutting portion of the tool, (c) replacing the tool when the wear on a cutting portion exceeds a selected limit.
Claim 13
Dependent Claim
37 words
Apparatus as in claim 10, wherein the held structure comprises a cantilever structure that extends from the substantially more massive holding means, and the cutting portion of the tool is at the outer end of the cantilever.
Claim 14
Dependent Claim
32 words
Apparatus as in claim 10, wherein the machining comprises turning, as on a lathe, and the normal component measuring direction is the direction in which the tool is fed along the workpiece.
Claim 15
Dependent Claim
38 words
Apparatus as in claim 10, wherein the machinging comprises milling or drilling with a rotating tool, and the normal component measuring direction is perpendicular to the axis of rotation and to the main cutting edges of the tool.
Claim 16
Dependent Claim
33 words
Apparatus as in claim 16, wherein the ratio comprises the root mean square value of the force component divided by the root mean square value of the vibration component during a predetermined time.
Claim 17
Dependent Claim
43 words
Apparatus as in claim 10, wherein the tool has primary and secondary cutting edges; each having a flank, and the computing means comprises means for computing the amount of wear on the flank of the primary and secondary cutting edges of the tool.
Claim 18
Dependent Claim
24 words
Apparatus as in claim 15, wherein the reponse providing means comprises means for providing a visual display indicative of the computed amount of wear.
Claim 19
Dependent Claim
24 words
Apparatus as in claim 15, wherein the response providing means comprises means for automatically adjusting the cutting conditions to control the rate of wear.
Claim 20
Dependent Claim
36 words
Apparatus as in claim 15, wherein the response providing means comprises means for automatically adjusting the position of the tool relative to the workpiece to compensate for the recession of the cutting edges of the tool.
Claim 21
Dependent Claim
27 words
Apparatus as in claim 15, wherein the response providing means comprises means for automatically replacing the tool when the wear on the flank exceeds a selected limit.
Claim 22
Dependent Claim
23 words
Apparatus as in claim 10, wherein the means for measuring the said dynamic force component comprises force transducer means and bandpass filter means.
Claim 23
Dependent Claim
13 words
Apparatus as in claim 20, wherein the force transducer means comprises a dynamometer.
Claim 24
Dependent Claim
43 words
Apparatus as in claim 10, wherein the means for measuring the said component of vibration comprises accelerometer means, whose output is connected to bandpass filter means, whose output is connected to double integration means, whose output is connected to direct current offset means.
Claim 25
Dependent Claim
19 words
Apparatus as in claim 10, wherein the computing means comprises analog to digital converter means and data processing means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-16 | 1989-06-17 | 1989-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-16 | 1993-06-17 | 1993-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-16 | 1997-06-17 | 1997-12-17 | $7700.00 | Window Closed / Lapsed |