US4206393A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Numerical control systems for machine tools
Assignee: Nippon Gakki Co Ltd
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Filing: 1978-03-13
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Granted: 1980-06-03
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Expires: 1998-03-13
Abstract
Abstract In a numerical control system of a machine tool wherein a servo-system for driving tool, table etc. is controlled by a control instruction signal expressed by a given function equation, there are provided a control instruction signal generator which generates a signal representing a control instruction value, a correction device for producing a correction signal corresponding to a phase lag angle of a servo-drive system for driving a working shaft and a correction device for correcting the control instruction value in accordance with the correction signal.
Inventors
- 👤 Jiro Chiba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:16
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/416; G05B19/4163; G05B2219/00; G05B2219/30; G05B2219/41; G05B2219/41123; G05B2219/42; G05B2219/42186; Y; Y10; Y10T; Y10T29/00; Y10T29/17
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
134 words
A numerical control system for controlling the position of a machine tool with respect to a workpiece which is moving in a predetermined path, wherein the position of the workpiece is controlled by a control unit in response to a position instruction input, said control unit including a position detector for determining the actual position of the workpiece, comprising: a generator for generating a control instruction signal which is a predetermined function of the actual position of the workpiece; a servo-system for controlling the position of the machine tool, wherein said control instruction signal is the input to said servo-system; and a correction device, for generating a correction signal and for changing the value of the control instruction signal in accordance with the correction signal to compensate for delay errors inherent in said servo-system.
Claim 2
Dependent Claim
134 words
A numerical control system for controlling the position of a machine tool with respect to a workpiece which is moving in a predetermined path, wherein the position of the workpiece is controlled by a control unit in response to a position instruction input, said control unit including a position detector for determining the actual position of the workpiece, comprising: a generator for generating a control instruction signal which is a predetermined function of the actual position of the workpiece; a servo-system for controlling the position of the machine tool, wherein said control instruction signal is the input to said servo-system; and a correction device, for generating a correction signal and for changing the value of the control instruction signal in accordance with the correction signal to compensate for delay errors inherent in said servo-system.
Claim 3
Dependent Claim
25 words
The numerical control system according to claim 1 wherein said correction device includes an addder which adds said correction signal to said control instruction signal.
Claim 4
Dependent Claim
48 words
The numerical control system according to claim 1 wherein said correction device includes a memory device in which a plurality of correction values are preset, and a read device for reading said memory device by utilizing predetermined positions of the workpiece as the addresses of said memory device.
Claim 5
Dependent Claim
52 words
The numerical control system according to claim 1 wherein said correction device includes a calculator, whose input is said control instruction signal, for effecting calculations corresponding to all transfer functions of said servo-system, and means for substracting the output of said calculator from said control instruction signal to obtain the correction signal.
Claim 6
Dependent Claim
66 words
The numerical control system according to claim 1 wherein said correction device includes a comparator which compares a feedback signal from the servo-system, said feedback signal corresponding to the position of the machine tool, with said control instruction signal for producing a signal representing the difference between the control instruction signal and the feedback signal, and an intermittent operation device for intermittently operating said comparator device.
Claim 7
Dependent Claim
61 words
The numerical control system according to claim 5 wherein the workpiece is driven by a rotating reference shaft and wherein said intermittent operation device comprises means for presetting at least one predetermined angle of the reference shaft, and means for generating a signal which operates said comparator only when the rotary angle of said reference shaft coincides with the present angle.
Claim 8
Dependent Claim
37 words
The numerical control system according to claim 1 wherein said generator comprises means for decomposing a function equation into a plurality of Fourier components and for independently calculating said components, and means for adding together said components.
Claim 9
Dependent Claim
78 words
The numerical control system according to claim 1 wherein said workpiece is a pin journal of a crankshaft, and said control instruction signal is expressed by the following function equation: Y(t)=E cos ωt+√(R+L).sup.2 -E.sup.2 sin.sup.2 ωt, where ω represents the angular velocity of said pin journal, L the radius of said tool, R the radius of said pin journal, and E the distance between the center of said pin journal and the center of rotation of said crankshaft.
Claim 10
Dependent Claim
113 words
A numerical control system for controlling the position of a machine tool with respect to the side of a cylindrical workpiece which is rotating eccentrically, comprising: a position detector for determining the angular position of the workpiece; a generator connected to said position detector for generating a control instruction signal which is a predetermined function of the angular position of the workpiece; a servo-system for controlling the position of the machine tool in response to said control instruction signal; and a correction device, connected to the generator, for generating a correction signal and changing the value of the control instruction signal in order to compensate for time delay errors inherent in said servo-system.
Claim 11
Dependent Claim
113 words
A numerical control system for controlling the position of a machine tool with respect to the side of a cylindrical workpiece which is rotating eccentrically, comprising: a position detector for determining the angular position of the workpiece; a generator connected to said position detector for generating a control instruction signal which is a predetermined function of the angular position of the workpiece; a servo-system for controlling the position of the machine tool in response to said control instruction signal; and a correction device, connected to the generator, for generating a correction signal and changing the value of the control instruction signal in order to compensate for time delay errors inherent in said servo-system.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-06-03 | 1983-12-03 | 1984-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-03 | 1987-12-03 | 1988-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-03 | 1991-12-03 | 1992-06-03 | $7700.00 | Window Closed / Lapsed |