NZ618241B2 - Method to improve process stabilization - Google Patents
Method to improve process stabilization Download PDFInfo
- Publication number
- NZ618241B2 NZ618241B2 NZ618241A NZ61824112A NZ618241B2 NZ 618241 B2 NZ618241 B2 NZ 618241B2 NZ 618241 A NZ618241 A NZ 618241A NZ 61824112 A NZ61824112 A NZ 61824112A NZ 618241 B2 NZ618241 B2 NZ 618241B2
- Authority
- NZ
- New Zealand
- Prior art keywords
- time
- welding
- welding process
- current pulse
- magnitude
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 57
- 238000011105 stabilization Methods 0.000 title description 6
- 238000003466 welding Methods 0.000 claims abstract description 115
- 238000004891 communication Methods 0.000 claims description 10
- 239000002184 metal Substances 0.000 claims description 10
- 229910052751 metal Inorganic materials 0.000 claims description 10
- 230000004907 flux Effects 0.000 claims description 7
- 239000007789 gas Substances 0.000 description 7
- 230000003750 conditioning Effects 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 3
- 230000000875 corresponding Effects 0.000 description 3
- 239000011261 inert gas Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 230000002459 sustained Effects 0.000 description 3
- 239000010953 base metal Substances 0.000 description 2
- 239000011324 bead Substances 0.000 description 2
- 239000000945 filler Substances 0.000 description 2
- 230000000977 initiatory Effects 0.000 description 2
- 230000001737 promoting Effects 0.000 description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 2
- 239000010937 tungsten Substances 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- 238000009529 body temperature measurement Methods 0.000 description 1
- 230000001419 dependent Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000006011 modification reaction Methods 0.000 description 1
- 230000000051 modifying Effects 0.000 description 1
- 230000003287 optical Effects 0.000 description 1
- 238000007778 shielded metal arc welding Methods 0.000 description 1
- 239000004544 spot-on Substances 0.000 description 1
- 230000001960 triggered Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/06—Arrangements or circuits for starting the arc, e.g. by generating ignition voltage, or for stabilising the arc
- B23K9/067—Starting the arc
- B23K9/0672—Starting the arc without direct contact between electrodes
- B23K9/0673—Ionisation of the arc gap by means of a tension with a step front (pulses or high frequency tensions)
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/06—Arrangements or circuits for starting the arc, e.g. by generating ignition voltage, or for stabilising the arc
- B23K9/073—Stabilising the arc
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/09—Arrangements or circuits for arc welding with pulsed current or voltage
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/10—Other electric circuits therefor; Protective circuits; Remote controls
Abstract
Systems and methods for providing a start in a welding process are disclosed. The system includes a power circuit and a control circuit. The power circuit generates welding output power for a welding process. The control circuit controls the start of the welding process by generating a current pulse (440). The magnitude of the current pulse and the period of time for applying the current pulse depend on a selected run-in setting. (440). The magnitude of the current pulse and the period of time for applying the current pulse depend on a selected run-in setting.
Description
METHOD TO IMPROVE PROCESS STABILIZATION
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application
No. 61/490,329 filed May 26, 2011, and U.S. Provisional Patent Application No.
61/547,668 filed October 14, 2011, the contents of which are both hereby incorporated
by reference in their entireties.
BACKGROUND
The present application generally relates to improving arc characteristics
of a welder.
SUMMARY
Welding systems can experience erratic operation during the start of the
welding process due to temperatures of the weldment and filler wire not having yet
stabilized. Additionally, welding systems can exhibit repeated stubbing, which
manifests as a series of violent contacts of an electrode and work piece. The stubbing
can be audible and may be telegraphed through the Metal Inert Gas (MIG) welding gun
to the user’s hand. The stubbing prolongs and impedes initiation of the weld, making
optimal steady-state settings difficult to establish. Welding systems encountering these
problems may not provide for optimal welds.
The present disclosure discusses optimizing starting characteristics by
providing, at the start of the welding process, a controlled current pulse that is based on
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output voltage and run in settings, for example. Additionally, the present disclosure
discusses optimizing starting characteristics and preventing stubbing by optimizing at
the start of the welding process, output voltage, wire feed, and inductance, for example.
In a first broad aspect the invention provides a system for providing an
improved start in a welding process comprising: a power circuit for generating welding
output power for a welding process; and a control circuit in communication with the
power circuit to control the start of the welding process, the control circuit being
configured to: receive a selection of a run in setting; and provide a current pulse at a
start of the welding process for a pre-determined period of time determined by the run-
in setting, wherein the current pulse has a peak magnitude that is based on the run in
setting.
In a second broad aspect the invention provides a system for providing an
improved start in a welding process comprising: a power circuit for generating welding
output power for a welding process; and a control circuit in communication with the
power circuit to control the start of the welding process, the control circuit being
configured to: receive a selection of a voltage setting; receive a selection of a run-in
percentage; and provide a current pulse at a start of the welding process for a pre-
determined period of time determined by the run-in percentage, wherein the current
pulse has a peak magnitude that is based on the voltage setting.
A method for generating a weld during a start of a welding process is also
provided. The method includes generating, by a power circuit, welding output power.
The method includes continuously determining, by a control circuit in communication
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with the power circuit, a welding energy output or a time that the welding output power
is provided. The method includes controlling, by the control circuit during the start of the
welding process, a welding parameter until the welding energy output exceeds an
energy output threshold or until the time exceeds a time threshold.
Further objects, features and advantages of this application will become
readily apparent to persons skilled in the art after a review of the following description,
with reference to the drawings and claims that are appended to and form a part of this
specification.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings described herein are for illustration purposes only and are
not intended to limit the scope of the present disclosure in any way.
is a schematic view of a welding system;
is a perspective view of a housing which contains the welding
system of
is a front view of an interface on the housing of ;
is a flow chart illustrating a method of controlling output power
during startup;
is a flow chart illustrating a method of expediting process
stabilization during weld startup;
is a flow chart illustrating another method of expediting process
stabilization during weld startup;
6348253_1 (GHMatters) P95560.NZ MILESF
is a wave form where the method of has been combined
with the method of or 5; and
is a schematic view of a processing system for implementing the
methods described herein.
It should be understood that throughout the drawings, corresponding
reference numerals indicate like or corresponding parts and features.
DETAILED DESCRIPTION
The term “substantially” used herein with reference to a quantity or
mathematical relationship includes (1) a variation in the recited quantity or relationship
of an amount that is insubstantially different from a recited quantity or relationship for an
intended purpose or function, or (2) a variation in the recited quantity or relationship of
an amount that produces the same quality.
Now referring to a power supply for a welding system 100 is
provided. The power supply 110 receives input power 112 which may be an alternating
current power line, for example a 220 volt AC power line. However, it is understood
that the power supply 110 may be adaptable to receive a range of voltages, for example
between 187 to 276 volts AC. In addition, it may also be possible to configure the
power supply for other voltage ranges depending on the application and required
welding output power. The power supply 110 provides a direct current power output
voltage 114 that may be used as a welding output power 116. In some
implementations, the power supply 110 may be used for stick welding (also known as
Shielded Metal Arc Welding or SMAW) or various other welding applications such as
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MIG (Metal Inert Gas, also known as gas metal arc welding or GMAW), flux core arc
welding, TIG (tungsten inert gas welding, also known as Gas Tungsten Arc Welding or
GTAW), plasma arc, or other welding processes. Therefore, in one example the current
return lead of the welding output power 116 may be provided to a part 118 that is to be
welded, and the supply voltage may be provided to an electrode, for example a stick
120 or wire 122. Therefore, as the stick 120 comes in contact with the part 118 an arc
may be formed that melts both the base metal and electrode and cooperates to form a
weld. In other implementations, the output voltage may be provided through a wire 122
which may be continuously fed to the part to form a continuous weld. In TIG mode the
electrode is not melted, and generally only the base metal is melted.
The power supply 110 may control the output voltage and the output
current, as well as the feeding of the wire to optimize the welding process. In addition,
the power supply 110 may be connected to one group of accessories 124 including for
example a remote wire feeder 126, a spool gun 128, or a push/pull gun 130. Further,
the power supply 110 may be connected to other groups of accessories 132, for
example through an 8-pin connector. The second group of accessories 132 may
include a MIG gun 134, a smart gun 136, a foot pedal 138, a pendant 140, a TIG gun
142, and/or a remote control/trigger 144.
Within the power supply 110, the input power 112 may be provided to a
circuit breaker or switch 154. Power may be provided from the circuit breaker 154 to a
power circuit 150. The power circuit 150 may condition the input power to provide a
welding output power 116, as well as, for powering various additional accessories to
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support the welding process. The power circuit 150 may also be in communication with
the control circuit 152. The control circuit 152 may allow the user to control various
welding parameters, as well as, providing various control signals to the power circuit
150 to control various aspects of the welding process. The power from the circuit
breaker 154 may be provided to an EMI filter 156 of the power circuit 150. Power is
provided from the EMI filter 156 to an input bridge 158. Power may be provided from
the input bridge 158 to a conditioning circuit 162. The conditioning circuit 162 may
include a boost circuit, a transformer, as well as a power factor correction circuit.
Power is provided from the conditioning circuit 162 to the inverter 160 where the power
is converted to a DC signal 114 thereby providing welding output power 116. Power
may also be provided to a bias circuit 170 to power a number of accessories internal or
external to the power supply 110 that facilitate operation of the power supply and
welding process. For example, the bias circuit 170 may provide power to gas solenoid
valves 172, fans 174, as well as, other accessory devices. In addition, power is
provided to a motor drive circuit 164 that is in communication with a motor 166. The
motor 166 may be in communication with a feed mechanism 168 configured to feed
wire 122 to a weld gun for use in creation of the weld. The control circuit 152 may
provide control signals to any of the previously mentioned circuits in the power circuit
150 to optimize the weld process and performance of the power supply 110. The
control circuit 152 may include a pulse width modulator 182 and a processor 184 for
analyzing various weld characteristics and calculating various weld parameters
according to user settings, as well as, various feedback signals. In addition, an
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interface circuit 186 may be provided to control a display 188 that may provide
information to the user of the welding system. The display 188 may include an LED
display, a LCD display, or various other known display technology. The display may
provide various menu choices to the user, as well as, providing various feedback on the
welding process including the values of various parameters or graphs of previous
welding characteristics. The controls 190 may also be in communication with the
interface circuit 186 to allow the user to provide input such as various welding
parameters to control the operation of the welding process.
The power supply 110 may further include a voltage reducing device
(VRD) circuit 192, a low-power circuit that detects contact between the part 118 to be
welded and the electrode. When an open circuit condition is detected between the
electrode and the work piece, the VRD circuit 192 may reduce the maximum open
circuit voltage to safe levels. When contact is made and/or the load is below a
threshold resistance, the VRD circuit 192 may no longer reduce the voltage and thus
may allow the welding system 100 to operate at full power. The VRD circuit 192 may
be in communication with a timer 194. The timer 194 may be implemented as software
as part of the control circuit 152, or may be comprised of an electronic circuit.
Now referring to , a housing 200 is provided that may be
implemented with the welding system 100. The housing 200 may contain the power
supply 110, and may further include a user interface 202 and a front connection panel
204. The front connection panel 204 may, for example, be used for connecting the
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power supply 110 to the first and second groups of accessories 124 and 132, as
discussed above.
Now referring to , a particular implementation of a user interface
202 is provided that may include various inputs selectable by a user and various
indicators and displays. A power indicator 210 may indicate when the power supply
110 is receiving the input power 112. A fault light 220 may indicate when the welding
process has entered a fault condition. A VRD “on” indicator 230 may indicate when the
VRD is on, and a VRD “off” indicator 232 may indicate when the VRD is off.
A mode selection input 240 may allow the user to select a desired welding
process. The mode selection input 240 may be a button which when pressed causes
the power supply 100 to cycle through and select a welding process. Three welding
process indicators 242, 244, 246 may respectively light upon selection of, for example,
MIG, TIG, or stick welding. The MIG selection provides a suitable configuration for both
gas metal arc welding and flux core arc welding.
A trigger interlock input 270 may allow a user to select between 2T and 4T
modes for MIG, TIG and stick welds that are activated via an electric switch. The 2T
mode allows the user to push and hold the switch to activate and release the switch to
deactivate. The 4T mode allows the user to push and release the switch to activate,
then push and release the switch again to deactivate. An indicator 272 may light when
the 2T mode is selected, and an indicator 274 may light when the 4T mode is selected.
An amperage input 252 may allow a user to select a desired output
current. A wire feed speed input 254 may allow a user to select a desired wire feed
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speed of the wire 122. The desired wire feed speed may be a desired steady-state wire
feed speed. In some implementations, the inputs 252 and 254 may be combined into
an adjustable knob. A user may press the adjustment knob to cycle between the inputs
252 and 254, and then turn the adjustment knob to select a desired value of the current
or wire feed speed. The selected desired value may be displayed on a display 250,
which may be a super bright red LED display.
A voltage input 262 may allow a user to select a desired output voltage of
the welding signal. An inductance input 264 may allow a user to select a desired
inductance which, for example, may optimize weld bead characteristics. An arc force
input 266 may allow a user to select desired properties of arc force. A down slope input
268 may allow a user to select a down slope time, which is a function of the down ramp
rate of the output current. In some implementations, the inputs 262, 264, 266, and 268
may be combined into an adjustable knob. A user may press the adjustment knob to
cycle between the inputs 262, 264, 266, and 268, and then turn the adjustment knob to
select a desired value of the voltage, inductance, arc force, or down slope. The
selected desired value may be displayed on a display 260, which may be a super bright
red LED display.
An advanced features input 280 may allow a user to select menus and
toggle through various further inputs, which are displayed on the displays 250 and 260.
A MIG welding main menu may provide inputs for operation control, pre-flow, spot
on/off, spot time, stitch on/off, stitch time, dwell time, run-in percentage, post-flow, burn
back time, wire sharp, and/or a setup submenu. The setup submenu may provide
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inputs for wire feed units, amperage calibration, voltage calibration, wire speed
calibration, arc hour display, VRD (on, off or triggered), total weld energy (for heat input
computation), and/or factory defaults. A stick welding main menu may provide inputs
for operation control, hot start on/off, hot start time, hot start amperage, and/or a setup
submenu. The setup submenu may provide inputs for arc hour display, VRD disable,
and factory defaults. The TIG main menu may provide inputs for operation control, pre-
flow, post-flow, and a setup submenu. The setup submenu may provide inputs for arc
hour display, VRD disable, and factory defaults.
Burn back time may refer to an adjustable period of time that the power
supply 110 may provide power for the welding process after the wire feed stops in order
to burn back the wire and prevent it from sticking in the weld puddle. Wire sharp refers
to the application of predefined current outputs applied to the wire, for example, a rapid
series of powerful current pulses after the motor 166 is de-energized. This prevents a
ball of molten metal from freezing on the end of the welding wire, and tapers the end of
the weld wire to a sharp point, promoting a cleaner start when welding resumes. The
current outputs terminate when an open-circuit is detected or after a predefined time or
condition is reached. Run-in percentage refers to a percent of wire feed speed. The
percentage may range, for example, from about 25 percent to about 150 percent of the
wire feed speed. The run-in setting may, for example, allow a user to temporarily alter
the selected wire feed speed to optimize MIG weld start characteristics.
The control circuit 152 may receive each of the quantities respectively
associated with each of the inputs. Further, although the above inputs are shown in
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particular implementations, each of the inputs may be configured as a dial, adjustment
knob, button, or switch, for example. Additionally, in some implementations, some of
the inputs may be automatically selected by the control circuit 152. Which inputs are
automatically selected and which inputs are user-selectable may depend on which
welding process is selected. In some implementations, some parameters, for example
wire diameter, material, gas, and joint design, may not be programmed into the control
circuit 152.
Now referring to a method 300 for controlling the start up power is
provided. The method 300 addresses improved initiation of gas metal arc welding and
flux core arc welding by restricting output pending the detection of energy transfer. The
method 300 described herein may be configured to prevent repeated, explosive
stubbing that can occur during startup. During GMAW and FCAW weld
commencement, output parameters such as current are controlled or altered until
output energy or sustained output power indicates that the wire and part to be welded
are hot enough for operation using optimized steady-state limits.
The ordering of the steps presented herein is merely one implementation
of the method 300. Those skilled in the art will recognize that the ordering may be
varied, that some steps may occur simultaneously, that some steps may be omitted,
and that further steps may be added. Moreover, each step involving the controller may
be implemented by configuring (e.g. programming) the controller to perform the step.
The method 300 starts in block 310. In block 312, the current is altered,
for example by limiting current to a maximum limit which may be predefined at, for
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example, 300 amps. Additionally, current may be limited from falling below a minimum
threshold which is below the maximum threshold. In block 314, the voltage may be
optionally temporarily offset. In block 316, the system may optionally increase the
inductance of the weld circuit. In some implementations, electronic inductance is also
temporarily increased based on whether a threshold output energy is reached or a
sustained output power over a period of time is provided, but is an independent element
of the system. The inductance may be changed by changing constants in a
proportional-integral loop which may for example be implemented in software. It is
understood that all of blocks 312, 314 and 316 may be performed together or in various
combinations.
In some other implementations, for stick welding (SMAW) arc force
adjustment may be controlled and for TIG some pulse or AC characteristics (e.g. pulse
amplitude and duration) may be adjusted. Other parameters used to regulate power
delivery could also be altered until, as will be discussed below, an output threshold is
passed. The modified limits prevent the wire or other consumable electrode from
vaporizing repeatedly before the weld puddle is fully developed. By abbreviating the
period before steady-state conditions are established, the weld bead is better formed
and undesirable spatter can be reduced near the starting point of the weldment.
In block 318, the control circuit 152 determines an output threshold, which
may be either an output energy threshold or a time threshold that output power has
been provided. The output threshold may or may not be predefined, and may be based
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on one or more, or any combination of user selectable welding parameters described
herein.
In block 328, the control circuit 152 then continuously determines the
output energy or a time that output power has been provided. Software may determine
output energy by calculating a time integral of the output power. Instantaneous output
power is a product of voltage and current measurements received from electronic
feedback sensors. In other implementations, to determine output energy, only a single
voltage or current measurement is required, because the software may determine
output current from output voltage, or vice versa, by mathematically calculating or using
a look-up table corresponding to the formula I = 20(V – 14V), where I is output current,
and V is output voltage, according to IEC 60974-1 (2005) section 11.2.3. Software may
also determine a time that output power is provided by determining how long output
power has been provided above a threshold. Preferably, the time may be at least 50
milliseconds or may be about 50 milliseconds. In some examples, the time is counted
and incremented only when the output power is above an output power threshold. For
example, the time threshold is reached when at least a quarter of the power estimated
by the IEC 60974-1 (2005) section 11.2.3 guidelines is provided for at least 50
milliseconds or about 50 milliseconds. When the time aggregates 50 milliseconds
(which can be nonconsecutive), then the time threshold is reached.
It is contemplated herein that operational amplifiers or other electronic
circuits could also be used to integrate the product of voltage and current
measurements, and to determine whether a threshold output power has been provided.
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Additionally, it is contemplated that greater or lesser current and time values could be
used. Also, calculations of time threshold or output energy may be based on optical,
accoustic or temperature measurements at the part to be welded.
In block 330, the control circuit 152 determines if the output threshold is
exceeded. For example, the control circuit 152 determines if the output energy exceeds
the output energy threshold, or if the time the output power is provided exceeds the
time threshold. If the output threshold is not exceeded, the method follows line 332 to
block 328. Referring again to block 330, if the output threshold is exceeded, the method
follows line 338 to block 340. In block 340, the welding process proceeds with normal
welding settings. For example, the current limit is restored to the steady-state current
limit to optimize steady-state weld performance. The steady-state current limit may
correspond to 3.75 times the standard IEC current, whereas the current limit used
before the threshold is reached may be 1.9 times the standard IEC current, for
example. The current limit used before the threshold is reached may be less than about
70%, or less than 60%, or less than about 50% of the steady-state current limit, for
example.
By reducing current limits, for example the maximum allowable current,
before a precomputed output energy or output power is dissipated at the contact point,
the wire remains intact as it is heated to the melting point, promoting a rapid, consistent
startup characteristic. The increased steady state limits allow brief excursions past the
power supply’s design capacity for sustained output current, enabling a small power
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supply to attain performance characteristics previously requiring a more capacious and
expensive design. The output of one design implementation is illustrated in
Now referring to FIGS. 4 and 5, methods 400 and 500 for expediting
process stabilization by providing an improved start is provided. The methods 400 and
500 may each be implemented in gas metal arc welding and flux core arc welding, for
example when the MIG welding setting is selected. The orderings of the steps
presented herein are merely particular implementations of the methods 400 and 500.
Those skilled in the art will recognize that the orderings may be varied, that some steps
may occur simultaneously, that some steps may be omitted, and that further steps may
be added. Moreover, each step involving the controller may be implemented by
configuring (e.g. programming) the controller to perform the step.
The method 400 starts in block 410. In block 410, the control circuit 152
may receive the run-in percentage from the run-percentage input and the output voltage
from the voltage input 262. In some implementations, the control circuit may also
receive the wire feed speed, inductance, burn-back time, and/or wire sharp setting from
their respective inputs. The method 400 may proceed from block 410 to block 420.
In block 420, the control circuit 152 may determine and/or store a
predefined period of time for applying a current pulse. The predefined period of time
may be based on the run in percentage and/or the output voltage. In some
implementations, the predefined period of time may be determined according to the
formula A + B * (Run in percentage) + C * (Voltage setting), where A, B, and C may
each have any positive or negative values. In a particular implementation, the formula
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may have the values 33 μs – (47.2 μs) * (Run-in percentage) + (2.11 μs/V) * (Voltage
setting). As shown in the equations, the predefined period of time may be a linear
function or substantially a linear function of the run in setting and the voltage setting.
However, it is understood that various other function could be used including
exponential or quadratic relationships. The method 400 may proceed from block 420 to
block 430.
In block 430, the control circuit 152 may determine and/or store a
magnitude of the current pulse. In some implementations, a magnitude or magnitudes
of the current pulse over the predefined period of time may be independent of selected
welding parameters. The current pulse may have a maximum magnitude at the start of
the predefined period of time and decrease linearly or substantially linearly as a function
of time to a magnitude of about zero at the end of the predefined period of time. In other
implementations, the magnitude may decrease from a maximum magnitude to a
magnitude of about zero according to a nonlinear or substantially nonlinear, decaying
exponential or substantially decaying exponential, or parabolic or substantially parabolic
functions, or any other mathematical functions.
In some implementations, the maximum magnitude may have a
predefined value of between about 250 and about 1000 amps, or between about 400
and 500 amps, and in a particular implementation, about 450 amps. In some
implementations, the magnitude of the current pulse may remain constant or
substantially constant throughout the predefined period of time. In other
implementations, the magnitude profile of the current pulse may be based on the
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inductance, wire feed speed, burn-back time, wire sharp setting, or combinations
thereof. The method 400 may proceed from block 430 to block 440.
In block 440, the control circuit 152 may provide the current pulse at the
start of the welding process for the predefined period of time. The control circuit 152
operates in current control mode to control the current pulse according to the
abovementioned magnitude profiles.
The method 500 starts in block 510. In block 510, the control circuit 152
may receive the run-in setting from the run-in setting input and the desired output
voltage from the voltage input 262. In some implementations, the control circuit may
also receive the wire feed speed, inductance, burn-back time, and/or wire sharp setting
from their respective inputs. The method 500 may proceed from block 510 to block 520.
In block 520, the control circuit 152 may determine and store a peak
magnitude of the current pulse. The current pulse may have a peak magnitude at the
start of a period of time and decrease linearly or substantially linearly as a function of
time to a magnitude of about zero at the end of the period of time. In other
implementations, the magnitude may decrease from a maximum magnitude to a
magnitude of about zero according to a nonlinear or substantially nonlinear, decaying
exponential or substantially decaying exponential, or parabolic or substantially parabolic
functions, or any other mathematical functions. The period of time may be a predefined
period of time, for example 82 milliseconds. The peak magnitude may be determined
according to the formula A + B * (Run-in speed) + C * (Voltage setting), where A, B, and
C may each have any positive or negative real numbers. In a particular implementation,
6348253_1 (GHMatters) P95560.NZ MILESF
the formula may have the values 217 amps – (310 amps) * (Run-in speed
setting/100%) + (13.9 amps / volts) * (Voltage setting). The run in speed is a setting in
percent of the wire feed speed during run in with respect to the welding wire feed
speed. For example, if the welding wire feed speed is 500 inches per minute and the
run in speed setting was 80% the run in wire speed would be 400 inches per minute.
The voltage setting is the desired voltage during welding. As shown in the equations,
the peak magnitude may be a linear function or substantially a linear function of the run
in setting and the voltage setting. In other implementations, the magnitude of the
current pulse may remain constant or substantially constant at the peak magnitude
throughout the period of time. The method 500 may proceed from block 520 to block
530.
In block 530, the control circuit 152 may provide the current pulse at the
start of the welding process for the predefined period of time. The control circuit 152
operates in current control mode to control the current pulse according to the
abovementioned magnitude profiles.
In each of the methods 400 and 500, rather than starting at the maximum
magnitude, the current pulse may instead first increase from zero to the maximum
magnitude over a period of time, which can be predefined based on user-selected or
programmed welding parameters, such as run in percentage, output voltage,
inductance, wire feed speed, burn-back time, wire sharp setting, or combinations
thereof. The increase may reach the maximum magnitude according to a linear or
substantially linear, nonlinear or substantially nonlinear, exponentially increasing or
6348253_1 (GHMatters) P95560.NZ MILESF
substantially exponentially increasing, logarithmically increasing or substantially
logarithmically increasing, or parabolic or substantially parabolic functions, or any other
mathematical functions. After the maximum magnitude is reached, the current may drop
off in the manner discussed earlier.
In each of the methods 400 and 500, it may intended that in some
implementations, the energy provided by the current pulse is predefined. That is, the
parameters upon which the current pulse is dependent may be set so that a predefined
(e.g. programmed) amount of energy is provided by the current pulse. The energy may
be determined by calculating a time integral of the output power. The output power may
be determined by multiplying the output voltage and the output current. In other
implementations, the energy may not be predefined.
In each of the methods 400 and 500, the current pulse may reduce or
largely eliminate periods of initial erratic operation during the initial stages of the
welding process due to temperatures of the weldment and filler wire not having yet
stabilized. The weld puddle develops and reaches steady-state temperature as the
current pulse decreases. The total energy provided by the current pulse may be
optimized for sufficient preheating, yet may also be kept low enough such that the extra
current does not vaporize the wire. Sufficient preheating provided by the current pulse
may thus expedite stabilization of the welding process.
Now referring to a waveform graph 600 is provided that shows
operation of the method 300 of in conjunction with either the method 400 of or the method 500 of The graph 600 includes a current waveform 602 and a
6348253_1 (GHMatters) P95560.NZ MILESF
voltage waveform 604, each plotted as a function of time at the start of the welding
process. The methods may provide particularly desirable characteristics when used in
combination with one another and each combination is contemplated herein. For
example, the current limiting method 300 may be implemented directly after and in
combination with either of the methods 400 or 500, as illustrated in The time
segment 606 of the waveforms 602 and 604 corresponds to the methods of FIGS. 4 or
, the time segment 608 of the waveforms 602 and 604 corresponds to the method of
and the time segment 610 of the waveforms 602 and 604 is a steady-state
waveform.
Any of the controllers, control circuits, modules, servers, or engines
described may be implemented in one or more computer systems or integrated
controllers. One exemplary system is provided in The computer system 1000
includes a processor 1010 for executing instructions such as those described in the
methods discussed above. The instructions may be stored in a computer readable
medium such as memory 1012 or storage devices 1014, for example a disk drive, CD,
or DVD, or in some form of nonvolatile memory, internal or external to the processor,
such as EPROM or flash. The computer may include a display controller 1016
responsive to instructions to generate a textual or graphical display on a display device
1018, for example a computer monitor. In addition, the processor 1010 may
communicate with a network controller 1020 to communicate data or instructions to
other systems, for example other general computer systems. The network controller
1020 may communicate over Ethernet or other known protocols to distribute processing
6348253_1 (GHMatters) P95560.NZ MILESF
or provide remote access to information over a variety of network topologies, including
local area networks, wide area networks, the Internet, or other commonly used network
topologies.
In other embodiments, dedicated hardware implementations, such as
application specific integrated circuits, programmable logic arrays and other hardware
devices, can be constructed to implement one or more of the methods described
herein. Applications that may include the apparatus and systems of various
embodiments can broadly include a variety of electronic and computer systems. One or
more embodiments described herein may implement functions using two or more
specific interconnected hardware modules or devices with related control and data
signals that can be communicated between and through the modules, or as portions of
an application-specific integrated circuit. Accordingly, the present system
encompasses software, firmware, and hardware implementations.
In accordance with various embodiments of the present disclosure, the
methods described herein may be implemented by software programs executable by a
computer system or processor. Further, in an exemplary, non-limited embodiment,
implementations can include distributed processing, component/object distributed
processing, and parallel processing. Alternatively, virtual computer system processing
can be constructed to implement one or more of the methods or functionality as
described herein.
Further, the methods described herein may be embodied in a computer-
readable medium. The term "computer-readable medium" includes a single medium or
6348253_1 (GHMatters) P95560.NZ MILESF
multiple media, such as a centralized or distributed database, and/or associated caches
and servers that store one or more sets of instructions. The term "computer-readable
medium" shall also include any medium that is capable of storing, encoding or carrying
a set of instructions for execution by a processor or that cause a computer system to
perform any one or more of the methods or operations disclosed herein.
As a person skilled in the art will readily appreciate, the above description
is meant as an illustration of the principles of this invention. This description is not
intended to limit the scope or application of this invention in that the invention is
susceptible to modification, variation and change, without departing from spirit of this
invention, as defined in the following claims.
6348253_1 (GHMatters) P95560.NZ MILESF
Claims
Claims (27)
1. A system for providing an improved start in a welding process, the system comprising: a power circuit for generating welding output power for a welding process; a control circuit in communication with the power circuit to control the start of the welding process, the control circuit being configured to: receive a selection of a run-in setting; and provide a current pulse at a start of the welding process for a pre- determined period of time determined by the run-in setting, wherein the current pulse has a peak magnitude that is based on the run in setting.
2. The system of claim 1 wherein the welding process is gas metal arc welding.
3. The system of claim 1 wherein the welding process is flux core arc welding.
4. The system of any one of claims 1 to 3 wherein the control circuit is further configured to receive a selection of a voltage, and the peak magnitude being further based on the selected voltage. 6348253_1 (GHMatters) P95560.NZ MILESF
5. The system of any one of claims 1 to 3 wherein the peak magnitude is substantially a linear function of the run in setting.
6. The system of any one of claims 1 to 5 wherein the current pulse is provided for a predefined period of time.
7. The system of claim 6 wherein the predefined period of time is independent of user-selected welding parameters.
8. The system of any one of claims 1 to 7 wherein the current pulse has the peak magnitude at the start of the pre-determined period of time and decreases substantially linearly as a function of time to a magnitude of about zero at the end of the pre-determined period of time.
9. The system of any one of claims 1 to 7 wherein the current pulse has the peak magnitude at the start of the pre-determined period of time and decreases substantially exponentially as a function of time to a magnitude of about zero at the end of the pre-determined period of time.
10. A system for providing an improved start in a welding process, the system comprising: 6348253_1 (GHMatters) P95560.NZ MILESF a power circuit for generating welding output power for a welding process; a control circuit in communication with the power circuit to control the start of the welding process, the control circuit being configured to: receive a selection of a voltage setting; receive a selection of a run-in percentage; and provide a current pulse at a start of the welding process for a pre- determined period of time determined by the run-in percentage, wherein the current pulse has a peak magnitude that is based on the voltage setting.
11. The system of claim 10 wherein the welding process is gas metal arc welding.
12. The system of claim 10 wherein the welding process is flux core arc welding.
13. The system of any one of claims 10 to 12 wherein the peak magnitude is substantially a linear function of the voltage setting.
14. The system of claim 13 wherein the predefined period of time is independent of user-selected welding parameters. 6348253_1 (GHMatters) P95560.NZ MILESF
15. The system of any one of claims 10 to 14 wherein the current pulse has the peak magnitude at the start of the pre-determined period of time and decreases substantially linearly as a function of time to a magnitude of about zero at the end of the pre-determined period of time.
16. The system of any one of claims 10 to 14 wherein the current pulse has the peak magnitude at the start of the pre-determined period of time and decreases substantially exponentially as a function of time to a magnitude of about zero at the end of the pre-determined period of time.
17. The system of any one of claims 1 to 9, the control circuit being further configured to: receive a selection of a run in percentage; and provide a current pulse at a start of the welding process for a predefined period of time that is determined by the run in percentage.
18. The system of claim 17 wherein the welding process is gas metal arc welding.
19. The system of claim 17 wherein the welding process is flux core arc welding. 6348253_1 (GHMatters) P95560.NZ MILESF
20. The system of any one of claims 17 to 19 wherein the predefined period of time is substantially a linear function of the run in percentage.
21. The system of any one of claims 17 to 20 the control circuit being further configured to receive a selection of a voltage, and the predefined period of time being further based on a selected voltage.
22. The system of claim 21 wherein the predefined period of time is substantially a linear function of the voltage setting.
23. The system of any one of claims 17 to 22 wherein a magnitude of the current pulse is independent of user-selected welding parameters.
24. The system of any one of claims 17 to 23 wherein the current pulse has a maximum magnitude at the start of the predefined period of time and decreases substantially linearly as a function of time to a magnitude of about zero at the end of the predefined period of time.
25. The system of claim 24 wherein the maximum magnitude is between about 250 and about 1000 amps. 6348253_1 (GHMatters) P95560.NZ MILESF
26. The system of any one of claims 17 to 23 wherein the current pulse has the peak magnitude at the start of the predefined period of time and decreases substantially exponentially as a function of time to a magnitude of about zero at the end of the predefined period of time.
27. A system for providing an improved start in a welding process substantially as herein described with reference to the accompanying drawings.
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US201161490329P | 2011-05-26 | 2011-05-26 | |
US61/490,329 | 2011-05-26 | ||
US201161547668P | 2011-10-14 | 2011-10-14 | |
US61/547,668 | 2011-10-14 | ||
PCT/US2012/039516 WO2012162582A1 (en) | 2011-05-26 | 2012-05-25 | Systems for and method of providing an improved start in welding process with provision of a pulse period at the start |
Publications (2)
Publication Number | Publication Date |
---|---|
NZ618241A NZ618241A (en) | 2015-05-29 |
NZ618241B2 true NZ618241B2 (en) | 2015-09-01 |
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