US3705286A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric discharge machining device
Assignee: Individual
•
Filing: 1971-01-21
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Granted: 1972-12-05
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Expires: 1991-01-21
Abstract
Abstract An electrical discharge machining device comprising a plurality of detectors for detecting currents and voltages at different parts of the device and generating detection signals in response to the detection, a logic circuit for determining different machining conditions of the device by logical combination of the detection signals so as to generate different discerning signals corresponding to the different machining conditions, and a control means for controlling the machining device based on relative frequency ratios of different discerning signals. Said relative ratios may be determined by using integrating circuits.
Inventors
- 👤 Iwao Kondo
- 👤 Kenjiro Taoka
- 👤 Kenji Sasagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:56
CPC Classifications
B; B23; B23H; B23H7/00; B23H7/14; B23H7/20; B23H1/00; B23H1/02; B23H1/024
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
202 words
Device for machining a conductive workpiece by an intermittent discharge of a relatively large pulsed electric power for machining added onto a relatively small pulsed electric power for insulation breaking-through, being applied across a gap between said workpiece and a movable electrode, said device comprising; at least two means for separately and independently detecting voltages and currents of said pulsed power in the machining circuit; logic circuit means for analyzing in combination the detected voltage and current values to produce at least one of the signals representative of normal machining condition, non-discharge condition, short circuit condition, gap conductance condition and arcing condition; and means for counting the number of said respective signals for comparison with a number of control signals to provide a ratio of a predetermined value; and means for regulating, in response to deviation from said predetermined ratio value, at least one of a plurality of machining control factors including peak value of the machining current, current and voltage of the machining pulsed power, current and voltage of the breaking-through pulsed power, pulse width, wave form, pause time, rate and extent of electrode movement, duty factor, flow and pressure of the machining liquid to be fed, and short circuit current.
Claim 2
Dependent Claim
202 words
Device for machining a conductive workpiece by an intermittent discharge of a relatively large pulsed electric power for machining added onto a relatively small pulsed electric power for insulation breaking-through, being applied across a gap between said workpiece and a movable electrode, said device comprising; at least two means for separately and independently detecting voltages and currents of said pulsed power in the machining circuit; logic circuit means for analyzing in combination the detected voltage and current values to produce at least one of the signals representative of normal machining condition, non-discharge condition, short circuit condition, gap conductance condition and arcing condition; and means for counting the number of said respective signals for comparison with a number of control signals to provide a ratio of a predetermined value; and means for regulating, in response to deviation from said predetermined ratio value, at least one of a plurality of machining control factors including peak value of the machining current, current and voltage of the machining pulsed power, current and voltage of the breaking-through pulsed power, pulse width, wave form, pause time, rate and extent of electrode movement, duty factor, flow and pressure of the machining liquid to be fed, and short circuit current.
Claim 3
Dependent Claim
46 words
Device as claimed in claim 1, comprising means for determining a quantity corresponding to the magnitude of the gap conductance in proportion to the magnitude of the deviation from said ratio value, and means for controlling the extent of electrode movement in response to said quantity.
Claim 4
Dependent Claim
46 words
Device as claimed in claim 1, comprising means for determining a quantity corresponding to the magnitude of the gap conductance in proportion to the magnitude of the deviation of said ratio value; and means for controlling the rate of electrode movement in response to said quantity.
Claim 5
Dependent Claim
55 words
Device as claimed in claim 1, comprising an encoder for generating pulses representative of extent of electrode movement so as to provide a ratio of the number of said pulses counted with the number of the normal discharge pulses counted in said metering means, said encoder utilizing said ratio for directly controlling the duty factor.
Claim 6
Dependent Claim
55 words
Device as claimed in claim 1, comprising an encoder for generating pulses representative of rate of electrode movement so as to provide a ratio of the number of said pulses counted with the number of the normal discharge pulses counted in said metering means, said encoder utilizing said ratio for directly controlling the duty factor.
Claim 7
Dependent Claim
76 words
Device as claimed in claim 1, comprising pulse generator circuit means and sampling circuit means, the outputs of said circuits being connected so that the output signals from the former are counted with the latter; and means responsive to the number of counted signals reaching a preset value in said sampling circuit means for generating said signal on the output side of said sampling circuit means, said signal being adapted to actuate the logic circuit means.
Claim 8
Dependent Claim
64 words
Device as claimed in claim 1, said counting means comprising at least two analog integration circuit means into which at least two signals representative of machining conditions are supplied from said logic circuit means so as to form earliEr pulses on the output side of either of said integration circuit means; and means utilizing said differential time relation for regulating the machining control factors.
Claim 9
Dependent Claim
23 words
Device as claimed in claim 7, comprising a pulse generator generating output signals adapted to be used as one of said two signals.
Claim 10
Dependent Claim
24 words
Device as claimed in claim 7, comprising clock pulse generator means generating output signals adapted to be used as one of said two signals.
Claim 11
Dependent Claim
29 words
Device as claimed in claim 7, comprising pulse generator means and clock pulse generator means respectively generating output signals adapted to be used for regulating said machining control factors.
References Cited (Backward Citations)
US2882437A
Cited
US3340478A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-05 | 1976-06-05 | 1976-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-05 | 1980-06-05 | 1980-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-05 | 1984-06-05 | 1984-12-05 | $7700.00 | Window Closed / Lapsed |