US3811345A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adaptive control system for numerical control
Assignee: Fujitsu Ltd
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Filing: 1971-12-27
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Granted: 1974-05-21
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Expires: 1991-12-27
Abstract
Abstract Adaptive control system for a numerical control machine tool like a lathe with a control program which contains the information about the outline of raw workpiece prior to blocks commanding the desired outline of the manufactured workpiece. The length of movements of the bit of said machine towards the direction of the center of said workpiece at the beginning of the cutting is controlled in a manner such that the cutting depth of said bit is shorter than the length of the cutting edge of said bit, and the load of said machine in the cutting operation is controlled so as to be equal to the upper limit of the allowable load. The system of the present invention provides prevention of damage to the bit, a shorter manufacturing time and improved operation efficiency of said machine.
Inventors
- 👤 K Kobayashi
- 👤 S Hattori
- 👤 M Tamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 02:05
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/416; G05B19/4163; G05B2219/00; G05B2219/30; G05B2219/36; G05B2219/36571; G05B2219/49; G05B2219/49063; Y; Y10; Y10T; Y10T82/00; Y10T82/25; Y10T82/2502
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
430 words
An adaptive control system for a numerical control machine which controls the cutting depth of a cutting bit so that the load on the machine in operation is less than an upper allowable value, comprising: command data supply means to supply command data relating to the outline of a raw workpiece which precedes the command data relating to the desired outline of a manufactured workpiece, a pulse distribution unit to supply distribution pulses according to the command data, a motor drive circuit to drive a motor, control means connected electrically to said pulse distribution unit and motor drive circuit to process said distribution pulses, said control means comprising a first pulse generator to provide output pulses which control the cutting bit to move from the center of a workpiece in a +X direction when the torque exceeds said allowable value. detection means to detect whether the cutting depth is equalized to a present value which is shorter than the length of the bladed part of the cutting bit, a first counter for providing an addition of one to its contents every time distribution pulses in a +Z direction generate after the cutting depth reaches said preset value and providing a subtraction of one from the contents thereof every time direction pulses generate after the cutting depth reaches said preset value, a second counter for providing an addition of one to its contents every time either of the distribution pulses in a -X direction or the output pulses of said first pulse generator generate after the cutting depth reaches said preset value and providing a subtraction of one from its contents every time distribution pulses in a +X direction generate after the cutting depth reaches said preset value, first gate means to prevent the distribution pulses in the -Z direction from going to said motor drive circuit during the period from the time that said cutting depth reaches said preset value to the time that the content of said first counter reaches zero, second gate means to prevent the distribution pulses in the +Z direction from going to said motor drive circuit after the cutting depth reaches said preset value, third gate means to prevent the distribution pulses in the +X direction from going to said motor drive circuit during the period from the time the cutting depth reaches said preset value to the time the content of said second counter reaches zero, and fourth gate means to prevent the distribution pulses in the -X direction from going to said motor Drive circuit after the cutting depth reaches said preset value.
Claim 2
Dependent Claim
430 words
An adaptive control system for a numerical control machine which controls the cutting depth of a cutting bit so that the load on the machine in operation is less than an upper allowable value, comprising: command data supply means to supply command data relating to the outline of a raw workpiece which precedes the command data relating to the desired outline of a manufactured workpiece, a pulse distribution unit to supply distribution pulses according to the command data, a motor drive circuit to drive a motor, control means connected electrically to said pulse distribution unit and motor drive circuit to process said distribution pulses, said control means comprising a first pulse generator to provide output pulses which control the cutting bit to move from the center of a workpiece in a +X direction when the torque exceeds said allowable value. detection means to detect whether the cutting depth is equalized to a present value which is shorter than the length of the bladed part of the cutting bit, a first counter for providing an addition of one to its contents every time distribution pulses in a +Z direction generate after the cutting depth reaches said preset value and providing a subtraction of one from the contents thereof every time direction pulses generate after the cutting depth reaches said preset value, a second counter for providing an addition of one to its contents every time either of the distribution pulses in a -X direction or the output pulses of said first pulse generator generate after the cutting depth reaches said preset value and providing a subtraction of one from its contents every time distribution pulses in a +X direction generate after the cutting depth reaches said preset value, first gate means to prevent the distribution pulses in the -Z direction from going to said motor drive circuit during the period from the time that said cutting depth reaches said preset value to the time that the content of said first counter reaches zero, second gate means to prevent the distribution pulses in the +Z direction from going to said motor drive circuit after the cutting depth reaches said preset value, third gate means to prevent the distribution pulses in the +X direction from going to said motor drive circuit during the period from the time the cutting depth reaches said preset value to the time the content of said second counter reaches zero, and fourth gate means to prevent the distribution pulses in the -X direction from going to said motor Drive circuit after the cutting depth reaches said preset value.
Claim 3
Dependent Claim
64 words
The adaptive control system for a numerical control machine according to claim 1 wherein said control means further comprises delay means which provides an output signal during a predetermined period after the content of said second counter reaches zero, and a fifth gate means which supplies distribution pulses to said motor drive circuit during the time the output signal from said delay means exists.
Claim 4
Dependent Claim
178 words
The adaptive control system for a numerical control machine according to claim 2 wherein said control means further comprises: a second pulse generator which provides a predetermined frequency signal, a third counter which accumulates distribution pulses in the +X direction furing the time the output of said delay means exists, and pulses which said first pulse generator provides after the torque exceeds the allowable value, sixth gate means to count up said first counter every time said second pulse generator provides output pulses after said delay period finishes and to move the tool toward the starting point of the cutting operation in the +Z direction according to the output pulses from said second pulse generator until the content of the same reaches zero, and seventh gate means to subtract the content of the third counter every time said second pulse generator provides pulses after the content of the first counter reaches zero, and to move the tool toward the starting point of cutting operation in the -X direction according to the output pulses from said second pulse generator.
Claim 5
Dependent Claim
135 words
The adaptive control system for a numerical control machine according to claim 3 wherein said detection means comprises: a fourth counter to count pulses in the -X direction applied to said motor drive circuit, a detector to detect when the content of the fourth counter reaches the predetermined value, a fifth counter which accumulates the distribution pulses in the -X direction until the cutting depth reaches the preset value and is cleared to zero just when the content of first counter reaches zero, and a sixth counter which receives the content of said fifth counter when the cutting depth reaches the preset value, and is subtracted from the distribution pulses in the -X direction until the content of the sixth counter reaches zero during the period when the content of said third counter is zero.
Claim 6
Dependent Claim
155 words
The adaptive control system for a numerical control machine according to claim 4 further comprising: a seventh counter which counts up every time the block end signal between two command data is read and is cleared to zero when the content of the first counter reaches zero, an eighth counter to count the distribution end signal during the period when the cutting depth is not equal to the predetermined value, and a comparator to compare the content of the seventh counter with the content of the eighth counter, whereby the pulse distribution is not performed on the condition that the content of the seventh counter is not larger than the content of the eighth counter during the program blocks from the starting point of the program to the end point of the outline of the workpiece, but a distribution end signal is immediately provided and the next command data on the program tape is read.
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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) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |