U.S. patent application number 13/664455 was filed with the patent office on 2013-02-28 for methods and systems for monitoring and controlling electroerosion.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. The applicant listed for this patent is General Electric Company. Invention is credited to Michael Scott Lamphere, Yuanfeng Luo, Bin Wei, Renwei Yuan.
Application Number | 20130048612 13/664455 |
Document ID | / |
Family ID | 35888083 |
Filed Date | 2013-02-28 |
United States Patent
Application |
20130048612 |
Kind Code |
A1 |
Luo; Yuanfeng ; et
al. |
February 28, 2013 |
METHODS AND SYSTEMS FOR MONITORING AND CONTROLLING
ELECTROEROSION
Abstract
A method for monitoring machining in an electroerosion assembly
having a power supply and an electrode arranged across a gap from a
workpiece, includes measuring a voltage at a point in a voltage
waveform after a time delay t.sub.d of one half of a pulse width of
the voltage waveform. The measurements are repeated for multiple
pulses of the voltage waveform to obtain multiple voltages, each of
the voltages corresponding to a point in respective pulses. The
voltages are averaged to obtain an average voltage, which is
compared with at least one threshold voltage, to determine whether
the machining is in control. A control signal is generated if the
comparison indicates that the process is not in control, the
control signal being configured to regulate an operating parameter
of the power supply, and the control signal is supplied to the
power supply, if generated.
Inventors: |
Luo; Yuanfeng; (Clifton
Park, NY) ; Yuan; Renwei; (Shanghai, CN) ;
Wei; Bin; (Mechanicville, NY) ; Lamphere; Michael
Scott; (Hooksett, NH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
General Electric Company; |
Schenectady |
NY |
US |
|
|
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
35888083 |
Appl. No.: |
13/664455 |
Filed: |
October 31, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10996218 |
Nov 23, 2004 |
8323473 |
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13664455 |
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Current U.S.
Class: |
219/69.16 |
Current CPC
Class: |
B23H 1/02 20130101; B23H
7/16 20130101 |
Class at
Publication: |
219/69.16 |
International
Class: |
B23H 7/26 20060101
B23H007/26 |
Claims
1. A method for monitoring machining in an electroerosion assembly
having a power supply and at least one electrode arranged across a
gap from a workpiece, the electrode being energized by the power
supply that applies a potential difference .DELTA.V between the
electrode and the workpiece during a plurality of pulse-on periods,
said method comprising: measuring a voltage at a point in a voltage
waveform for the electroerosion assembly after a specified time
delay t.sub.d of at least about one half of a pulse width
.DELTA..tau. of the voltage waveform; repeating the measurement for
a plurality of pulses of the voltage waveform to obtain a plurality
of voltages, each of the voltages corresponding to a point in
respective ones of the pulses, wherein the pulses correspond to a
window; comparing each of the voltages with at least one threshold
voltage V.sub.th to classify each of the pulses as a normal or an
abnormal discharge pulse; generating at least one control signal if
the comparison indicates that at least a predetermined number of
abnormal discharge pulses are present in the window, the at least
one control signal being configured to regulate at least one
operating parameter of the power supply; and supplying the at least
one control signal to the power supply, if the control signal has
been generated.
2. The method of claim 1, wherein the window is a flying window,
said method further comprising selecting a window size.
3. The method of claim 2, wherein the electroerosion assembly is a
pulsed electroerosion assembly, wherein said measuring begins at
the time delay interval t.sub.d after a pulse-on state and ends at
a pulse-off state, and wherein the at least one control signal is
an instruction to the power supply selected from the group
consisting of an instruction to increase a duration of at least one
of a plurality of pulse-off periods, an instruction to decrease a
duration of at least one of the pulse-on periods, an instruction to
modify a peak current density provided to the electroerosion
assembly, an instruction to turn off the power supply and
combinations thereof.
4. An electroerosion assembly comprising: at least one electrode
configured to machine a workpiece across a gap upon application of
a potential difference .DELTA.V across said electrode and the
workpiece; a power supply configured to energize said electrode;
and a controller configured to: measure a voltage at a point in a
voltage waveform for the electroerosion assembly after a specified
time delay t.sub.d of at least about one half of a pulse width
.DELTA..tau. of the voltage waveform, repeat the measurement for a
plurality of pulses of the voltage waveform to obtain a plurality
of voltages, each of the voltages corresponding to a point in
respective ones of the pulses, compare the voltages with at least
one threshold voltage V.sub.th, to determine whether a machining
process is in control, generate at least one control signal if the
comparison indicates that the machining process is not in control,
the at least one control signal being configured to regulate at
least one operating parameter of said power supply, and supply the
at least one control signal to said power supply, if the control
signal has been generated.
5. The electroerosion assembly of claim 4, wherein the plurality of
pulses corresponds to a flying window, and wherein the averaging
comprises a point-by-point averaging.
6. The electroerosion assembly of claim 4, wherein said controller
is further configured to determine that the machining process is
not in control if the average voltage is less than the at least one
threshold voltage V.sub.th.
7. The electroerosion assembly of claim 4, wherein said controller
is configured to compare the voltages by: averaging the voltages to
obtain an average voltage; and comparing the average voltage with
at least one threshold voltage V.sub.threshold, to determine
whether the machining process is in control.
8. The electroerosion assembly of claim 15, wherein said controller
is configured to compare each of the voltages with at least one
threshold voltage V.sub.th to classify each of the pulses as a
normal or an abnormal discharge pulse, and wherein said controller
is configured to generate at least one control signal if the
comparison indicates that a predetermined number of abnormal pulses
are present in the window.
9. A method for monitoring a machining process in an electroerosion
assembly having a power supply and at least one electrode arranged
across a gap from a workpiece, the electrode being energized by the
power supply that applies a potential difference .DELTA.V between
the electrode and the workpiece during a plurality of pulse-on
periods, said method comprising: measuring a voltage at a point in
a pulse of a voltage waveform for the electroerosion assembly after
a specified time delay t.sub.d from a pulse-on state of the pulse,
the time delay t.sub.d being at least about one half of a pulse
width .DELTA..tau. of the voltage waveform; comparing the measured
voltage with at least one threshold voltage V.sub.threshold, to
determine whether the machining process is in control; generating
at least one control signal if the comparison indicates that the
process is not in control, the at least one control signal being
configured to regulate at least one operating parameter of the
power supply; and supplying the at least one control signal to the
power supply, if the control signal has been generated.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of U.S. patent application
Ser. No. 10/996,218, Yuanfeng Luo et al., entitled "Methods and
systems for monitoring and controlling electroerosion," which
patent application is incorporated by reference herein in its
entirety.
BACKGROUND
[0002] The present invention relates in general to electroerosion,
and more specifically to systems and methods for monitoring and
controlling an electroerosion process.
[0003] Electrochemical machining (ECM) and electrical discharge
machining (EDM) are conventional processes for machining material
in objects such as gas turbine components. ECM processes typically
pass an electrical current in the gap between an electrode(s) and a
workpiece for precision removal of amounts of material on the
workpiece to achieve a desired final configuration thereof with
substantially smooth surfaces. EDM processes circulate a dielectric
liquid between an electrode(s) and a workpiece, and electrical
discharges are generated in the gap between the electrode and the
workpiece. EDM is used, for example, to drill small film cooling
holes through the surfaces of turbine rotor blades and nozzle
vanes.
[0004] Both ECM and EDM processes use electrical current under
direct-current (DC) voltage to electrically power removal of the
material from the workpiece. However, in ECM an electrolyte (an
electrically conductive liquid) is circulated between the
electrode(s) and the workpiece for permitting electrochemical
dissolution of the workpiece material, as well as cooling and
flushing the gap region therebetween. In contrast, EDM processes
circulate a nonconductive (dielectric) liquid in the gap to permit
electrical discharges in the gap for removing the workpiece
material. As used herein, the term "electroerosion" should be
understood to apply to those electromachining processes that
circulate an electrolyte (electrically conductive liquid) in the
gap between the electrode(s) and the workpiece, these processes
enabling a high rate of material removal and reducing thermal
damages to the workpiece.
[0005] Beneficially, electroerosion processes provide for quicker
machining and have higher efficiencies as compared to other
electromachining methods in various applications, such as, blisk
roughing and machining, for example. Typically, in processes
utilizing an electroerosion assembly, a voltage potential is
generated across a gap between an electrode and a workpiece to be
machined, resulting in an electrical discharge in the gap.
According to physics of the electroerosion process, when the
machining electrode (cathode) approaches the workpiece (anode)
surface separated by the gap, an electrical discharge occurs
through the gap due to the voltage across the electrode and the
anode workpiece. The gap, which constitutes a machining zone, is
filled with a liquid electrolyte medium with moderate to low
electrical conductivity, and the gap allows for the flow of
electrolyte, which removes eroded particles from the gap in
addition to providing a suitable medium for electrical discharge or
sparking for electroerosion. A "normal" electrical discharge across
the gap results in desirable machining of the workpiece. An
"abnormal" discharge on the other hand results in undesirable
errors in machining which may have a direct repercussion on the
surface finish of the machined workpiece. In some cases, the
workpiece or the electroerosion assembly may be damaged due to
short-circuiting because of a lack of an effective control.
[0006] Such errors can be avoided by timely and accurately
monitoring of discharge patterns, detecting abnormal discharges and
accordingly taking corrective measures. However, the systems
currently employed in EDM for monitoring discharge patterns are
generally insufficient and/or unsuitable for monitoring
electroerosion processes and typically generate errors in detecting
a discharge type. The errors may amount to incorrectly classifying
normal discharges as abnormal and vice versa, which makes the
electroerosion process susceptible to the risks mentioned above.
For example, many conventional EDM assemblies employ an ignition
delay detection method to determine whether a discharge is normal
or abnormal. In the ignition delay detection method, discharges
with an ignition delay are considered normal, whereas those without
an ignition delay are considered abnormal. However, as noted above,
electroerosion processes use electrolytes instead of the dielectric
liquids used for typical EDM processes. Accordingly, for
electroerosion processes, a number of the pulses without ignition
delay are normal discharges, and the conventional ignition delay
detection method improperly classifies many normal discharges as
abnormal, when used to monitor electroerosion processes.
[0007] Accordingly, there exists a need for accurate detection and
classification of voltage discharge in electroerosion processes.
Consequently, electroerosion processes and systems with accurate
monitoring and control are also desired.
BRIEF DESCRIPTION
[0008] An aspect of the present invention resides in a method for
monitoring machining in an electroerosion assembly having a power
supply and an electrode arranged across a gap from a workpiece. The
power supply energizes the electrode by applying a potential
difference between the electrode and the workpiece during multiple
pulse-on periods. The method includes measuring a voltage at a
point in a voltage waveform after a time delay t.sub.d of one half
of a pulse width .DELTA..tau. of the voltage waveform. The
measurements are repeated for multiple pulses of the voltage
waveform to obtain multiple voltages, each of the voltages
corresponding to a point in respective pulses. The voltages are
then averaged to obtain an average voltage, and the average voltage
is compared with at least one threshold voltage V.sub.th, to
determine whether the machining is in control. A control signal is
generated if the comparison indicates that the process is not in
control, the control signal being configured to regulate an
operating parameter of the power supply, and the control signal is
supplied to the power supply, if generated.
[0009] Another aspect of the invention resides in another method
for monitoring machining in an electroerosion assembly having a
power supply and an electrode arranged across a gap from a
workpiece. A voltage is measured at a point in a voltage waveform
after a time delay t.sub.d of one half of a pulse width
.DELTA..tau. of the voltage waveform. The measurement is repeated
for multiple pulses of the voltage waveform to obtain multiple
voltages, each of the voltages corresponding to a point in
respective pulses, the pulses corresponding to a window. The
voltages are compared with a threshold voltage V.sub.th to classify
the pulses as a normal or an abnormal discharge pulse. A control
signal is generated if the comparison indicates that a
predetermined number of abnormal discharge pulses are present in
the window. The control signal is configured to regulate an
operating parameter of the power supply, and is supplied to the
power supply, if generated.
[0010] Another aspect of the inventions resides in an
electroerosion assembly including an electrode configured to
machine a workpiece, located across a gap from the electrode. The
machining is achieved upon application of a potential difference
across the electrode and the workpiece. A power supply is
configured to energize the electrode is also included in the
electroerosion assembly that further includes a controller
configured to measure a voltage at a point in a voltage waveform
after a specified time delay t.sub.d of one half of a pulse width
.DELTA..tau. of the voltage waveform. The controller is also
configured to repeat the measurement for multiple pulses to obtain
multiple voltages, each of the voltages corresponding to a point in
respective pulses. The controller then compares the voltages with a
threshold voltage V.sub.th, to determine whether a machining
process is in control. The controller generates a control signal if
the comparison indicates that the machining process is not in
control, the control signal being configured to regulate an
operating parameter the power supply, and supplies the control
signal to the power supply, if generated.
DRAWINGS
[0011] These and other features, aspects, and advantages of the
present invention will become better understood when the following
detailed description is read with reference to the accompanying
drawings in which like characters represent like parts throughout
the drawings, wherein:
[0012] FIG. 1 is a schematic illustration of an electroerosion
assembly, according to an embodiment of the invention;
[0013] FIG. 2 illustrates a flow diagram of a method for monitoring
and control machining using the electroerosion assembly;
[0014] FIG. 3 illustrates a flow diagram of another method for
monitoring and control machining using the electroerosion
assembly;
[0015] FIG. 4 is a plot illustration characterizing various types
of discharges in machining using an electroerosion assembly;
[0016] FIG. 5 is a waveform illustrating an example of an applied
control signal;
[0017] FIG. 6 is a waveform illustrating another example of an
applied control signal; and
[0018] FIG. 7 is a waveform illustrating yet another example of an
applied control signal.
DETAILED DESCRIPTION
[0019] FIG. 1 illustrates an electroerosion assembly 100 according
to an embodiment of the invention. The electroerosion assembly 100
includes an electrode 10 configured for machining, arranged across
a gap 12 from a workpiece 14 to be machined. The gap 12 and at
least a portion of the electrode and the workpiece are submerged in
an electrolyte medium (not shown in the figures). A power supply 20
is configured for generating electric discharges that machine the
workpiece. Typically, the discharges cause particles at a machining
site of the workpiece to separate from the workpiece, thereby
machining the workpiece 14. The power supply 20 energizes the
electrode 10 by applying pulses of a potential difference .DELTA.V
to generate such discharges, in the gap 12 across the electrode 10
and the workpiece 14. The multiple applied pulses having a pulse
width .DELTA..tau. result in an applied voltage waveform having
multiple pulse-on and pulse-off states. In response to the applied
voltage waveform, the discharges in the gap 12 generate a voltage
waveform that represents the voltage in the gap 12, and the voltage
waveform comprises multiple discharge pulses. It is appreciated
that the applied waveform (having applied pulses) and the voltage
waveform (having discharge pulses, or "pulses") are distinct. A
servo controller 30 is provided for controlling mechanical
movements in the assembly 100, including controlling the gap 12,
the relative movement of the electrode 10 and the workpiece 14 for
alignment. A controller 40 is provided for monitoring and
controlling electroerosion processes or machining using the
electroerosion assembly 100. The controller 40 is coupled to the
power supply 20, the servo controller 30, the electrode 12 and the
workpiece 14.
[0020] The controller 40 is generally configured to, among other
functions, direct the power supply 20 to apply pulses of potential
difference .DELTA.V between the electrode 10 and the workpiece 14,
measure a voltage across the gap 12, generate selectable time
intervals, initiate the measurement after the passage of an
interval of time (or a time delay), average voltage values, compare
voltage values, and generate control signals to regulate the power
supply 20.
[0021] The controller 40 may include, without limitation, a
microprocessor or another computational device, a voltage
measurement device, a timing device, a pulse generation device, a
voltage comparison device, a data storage device, among others. All
such devices are well known in the art and any such suitable device
may be used without deviating from the scope of the invention.
[0022] FIG. 2 illustrates a method for monitoring machining in the
electroerosion assembly 100, according to an embodiment of the
invention. According to the method S100, after starting (S110) the
machining, a voltage is measured (S120) at a point after a
specified time delay t.sub.d, of at least half the applied pulse
width .DELTA..tau. from a pulse-on state of an applied pulse of the
applied voltage waveform. The time delay t.sub.d may be varied, for
example, to two-thirds of the applied pulse width .DELTA..tau., and
such variations are included within the scope of the present
invention. The measurement of the voltage as above is repeated
(S130) for multiple pulses of the voltage waveform, each
measurement being completed after a specified time delay from a
pulse-on state of applied pulses of the applied waveform. The
number of multiple voltage measurements may be set to a
predetermined number, such as four (4) voltage measurements, for
example. The multiple voltages, so measured, are averaged (S140) to
obtain an average voltage, V.sub.avg. The average voltage V.sub.avg
is then compared (S150) to a threshold voltage V.sub.th to
determine whether the machining is in control. In an embodiment,
the determination includes indicating the machining is "not in
control" if V.sub.avg is less than V.sub.th. If the machining is
indicated as being "not in control," a control signal is generated
(S160) to regulate at least one operating parameter of the power
supply 20. Operating parameters of the power supply include
durations of pulse-on or pulse-off states of the applied pulses,
voltage of the applied pulses, current supplied in the applied
pulses, among others. The control signal, if generated, is supplied
(S170) to the power supply.
[0023] It is appreciated that the averaging may be done using any
of the various averaging techniques including, but not limited to,
simple averaging, point-by-point averaging among others. For
example, a predetermined number of voltage measurements as above
may be repeated, and these measurements may be averaged. A
predetermined interval, which interval may include a number of
pulses is referred to as a window (also indicated by numeral 302 in
FIGS. 5-7). In one example, the window corresponds to six (6)
pulses and thus to an interval equal to six (6) applied pulse
widths (6*.DELTA..tau.). This example is illustrative, and the
invention is not limited to a window corresponding to any specific
number of pulses. In another embodiment, the window is a flying
window, which is a variable interval configured to include a
variable number of pulses. The flying window advantageously allows
for a flexible monitoring of the process, by increasing or
decreasing the number of pulses measured.
[0024] The control signal may be configured to regulate the power
supply 20 in a number of ways. According to one embodiment as
illustrated by FIG. 5, the control signal instructs the power
supply 20 to increase a duration of a pulse-off period 300 between
applied pulses to a longer duration of pulse-off period 310. An
instance 304 denotes a time at which the control signal is
supplied, and similar instances are also indicated for the FIGS. 6
and 7 respectively. In the embodiment of FIG. 5, the control signal
supplied at the instance 304, and the control signal is illustrated
as causing the pulse-off period duration 300 between two
simultaneous pulses, before the control signal was supplied, to be
increased to a longer pulse-off period duration 310, after the
control signal was supplied. According to another embodiment as
illustrated by FIG. 6, the control signal instructs the power
supply 20 to decrease the duration of a pulse-on period 320 of the
applied pulses to a decreased duration of pulse-on period 330.
According to yet another embodiment illustrated by FIG. 7, the
control signal instructs the power supply 20 to modify peak current
density supplied to the electroerosion assembly 100. The
modification includes decreasing the peak current density supplied
to the machining site when the peak current reaches a peak current
threshold limit indicated by the numeral 340. The values of various
pulse-on or pulse-off durations, threshold limits, as discussed may
be modified as per specific machining conditions and desired
machining quality, among other parameters. Various such values will
readily occur to those skilled in the art and are included within
the scope and spirit of the invention.
[0025] Advantageously, these techniques assist in restoring the
machining process to a normal condition, and also decrease the
energy supply to the machining site thereby minimizing the damage
to the electrode and workpiece. According to a yet another
embodiment, the control signal instructs the power supply 20 to
turn off when the machining process is out of control. It is
appreciated here that any one of the strategies as above, alternate
strategies, or various combinations of the above strategies may be
employed, by configuring the control signal appropriately.
[0026] At certain instances, the machining process may go "out of
control," which may mean a continued occurrence of "not in control"
discharges that do not resume to a normal condition even after
applying a control. Such "out of control" instances may occur for
example, on electrode distortion, cyclic arcing, bad electrolyte
flushing conditions, incorrigible arcing due to electrolyte
shortage, among others. Such instances may also be controlled by
the strategies as discussed above, for example, by turning off the
power supply. The machining may then be resumed after an
appropriate interval of time, or after another suitable remedial
action has been taken.
[0027] It is further noted that the discharge pulses may be
classified as normal or abnormal to indicate the normalcy of the
discharge. The two categories "normal" and "abnormal" correspond to
desirable and undesirable machining performance, respectively. In
certain instances, multiple closely spaced abnormal discharge
pulses may correspond to a "not in control" process. In certain
other cases, multiple continuous abnormal discharge pulses may
correspond to an "out of control" process. Under normal machining
conditions, the number of normal pulses is substantially greater
than the number of abnormal pulses. In a normal discharge, the
energy released by the discharge is used as explosive energy to
remove workpiece material as particles. Examples of normal
discharges include, but are not limited to, normal discharge with
an ignition delay 210 and normal discharge without an ignition
delay 220, examples of which are shown in FIG. 4. In an abnormal
discharge, which includes an "arc" state or a "short-circuit" state
of the discharge, a high amount of current may be generated,
generating a high amount of energy. Most of the energy released in
an abnormal discharge, however, is converted into excess heat
energy that may damage the electrode 10 or the workpiece 14, and in
some cases cause an undesirable deformation of the workpiece
surface. Examples of abnormal discharges are shown, for example in
FIG. 4, that include an arc with an ignition delay 230, an arc
without an ignition delay 240, an arc and discharge combined 250 (a
short circuit and a deformed wave pattern) among others. A
threshold voltage V.sub.th is marked on FIG. 4, and a discharge
voltage value greater than V.sub.th at the point of measurement
(after a time delay t.sub.d) indicates a normal discharge, whereas
a discharge voltage value less than V.sub.th indicates an abnormal
discharge. The threshold voltage value V.sub.th is chosen for
differentiating between a normal and an abnormal discharge and may
be determined experimentally for a particular electroerosion
assembly setup. The threshold voltage value V.sub.th varies based
on the machining conditions, for example the material being
machined and the electrolyte employed. In one embodiment, the
threshold voltage value V.sub.th is about 14.3 Volts. It is
appreciated here that in FIG. 4, voltage level indicated by
V.sub.th is indicative and not meant to be to scale.
[0028] A method S200 embodiment for monitoring machining in an
electroerosion assembly is illustrated in FIG. 3. Once the
machining is started (S210), a voltage is measured (S220) at a
point after a specified time delay t.sub.d, of at least half the
applied pulse width .DELTA..tau. from a pulse-on state of an
applied pulse of the applied voltage waveform. The time delay
t.sub.d may be varied, for example, to two-thirds of the applied
pulse width .DELTA..tau., and such variations are not limiting to
the present invention. The measurement of the voltage as above is
repeated (S230) for multiple pulses of the voltage waveform, each
measurement being done after a specified time delay from a pulse-on
state of applied pulses of the applied waveform. The multiple
pulses being measured in S230 correspond to a window, which is a
predetermined interval. In one embodiment, the window is a flying
window. The multiple measured voltages corresponding to multiple
pulses are then compared (S240) to at least one threshold voltage
V.sub.th to classify each of the discharge pulses in the window as
normal or abnormal. As discussed, the determination includes
indicating the pulse as abnormal if the measured voltage for that
pulse is less than V.sub.th. If the comparison indicates a
pre-determined number of pulses in the window as abnormal, a
control signal is generated (S250) to regulate at least one
operating parameter of the power supply 20. In an example, the
predetermined number of abnormal pulses required to generate a
control signal is set to six (6). However, this number is only an
example, and the window is not restricted to any specific number of
pulses. The control signal, if generated, is supplied (S260) to the
power supply.
[0029] The control signal is configured to employ any one or a
combination of control strategies by regulating an operating
parameter of the power supply 20, as also discussed earlier. It is
noted here that a single pulse voltage measurement may be measured
for generating a control signal. It is further noted that there may
be multiple threshold voltage values for comparison, similar to
V.sub.th. For example, a second threshold value V.sub.th2 (not
illustrated in the figures) may be included, and a pulse is
classified as abnormal if the measured voltage is greater than
V.sub.th2, and various such suitable voltage threshold values will
occur to those skilled in the art, and do not limit the
invention.
[0030] Use of the techniques and systems as above advantageously
allows for a well-monitored and controlled machining process. Among
other benefits, accidental damages to the workpiece, which at times
may be irreversible or untreatable, are minimized, thereby reducing
costs and in certain cases cycle times of manufacture of various
components. The methods and systems as disclosed also provide an
improved, online monitoring system for electroerosion
processes.
[0031] While only certain features of the invention have been
illustrated and described herein, many modifications and changes
will occur to those skilled in the art. It is, therefore, to be
understood that the appended claims are intended to cover all such
modifications and changes as fall within the true spirit of the
invention.
* * * * *