CN111843112A - Method and apparatus for controlling welding power and preheating power - Google Patents

Abstract

An example welding system, comprising: power conversion circuitry configured to: outputting welding type power to a welding circuit; and outputting preheating power to the preheater; and control circuitry configured to: receiving input selecting one of a plurality of welding protocols, each of the plurality of welding protocols specifying some combination of welding-type output power and pre-heat output power; and control the power conversion circuitry to output the welding-type power and the pre-heating power based on the selected one of the plurality of welding protocols.

Description

Method and apparatus for controlling welding power and preheating power

RELATED APPLICATIONS

This patent claims the benefit of U.S. provisional patent application serial No. 62/840,652 entitled "METHODS AND APPARATUS for controlling WELDING POWER AND preheating POWER" filed on 30/4/2019. U.S. patent application serial No. 62/840,652 is expressly incorporated herein in its entirety by this reference.

Background

The present disclosure relates generally to welding, and more particularly to methods and apparatus for controlling welding power and preheating power.

Welding is an increasingly common process in all industries. Welding is simply, by its very nature, the way two pieces of metal are joined together. A wide variety of welding systems and welding control schemes have been implemented for various purposes. In continuous welding operations, Metal Inert Gas (MIG) welding and Submerged Arc Welding (SAW) techniques allow a continuous bead to be formed by feeding a welding wire from a welding torch that is shielded by inert gas and/or flux. Such wire feed systems may be used with other welding systems, such as Tungsten Inert Gas (TIG) welding. Electrical power is applied to the wire and the circuit is completed through the workpiece to maintain a welding arc that melts the wire electrode and the workpiece to form the desired weld.

Disclosure of Invention

A method and apparatus for controlling welding power and pre-heating power is disclosed, substantially as shown in and described in connection with at least one of the figures, as set forth more completely in the claims.

Drawings

Fig. 1 illustrates an example welding system configured to deliver welding-type power to a welding accessory (such as a pre-heated wire feeder) for conversion to welding-type output power and pre-heated power, and to control the welding-type power and the pre-heated power based on input signals, in accordance with aspects of the present disclosure.

Fig. 2 is a block diagram of an example implementation of the pre-heating wire feeder of fig. 1.

FIG. 3 illustrates another example welding system configured to provide welding-type output power and pre-heating power to a welding torch and to control the welding-type power and pre-heating power based on an input signal, in accordance with aspects of the present disclosure.

Fig. 4a is a block diagram of an example implementation of the power conversion circuitry of fig. 1, 2, and/or 3.

Fig. 4b is a block diagram of another example implementation of the power conversion circuitry of fig. 1, 2, and/or 3.

FIG. 5 is a flow diagram representative of example machine readable instructions that may be executed by the example welding accessory of FIG. 1 or 2 and/or the example welding-type power supply of FIG. 3 to control welding-type power and pre-heating power based on input signals specifying a welding regime.

FIG. 6 is a flow diagram representative of example machine readable instructions that may be executed by the example welding accessory of FIG. 1 or 2 and/or the example welding-type power supply of FIG. 3 to cooperatively control welding-type power and pre-heating power based on an input signal.

The drawings are not necessarily to scale. Where appropriate, like or identical reference numerals have been used to indicate like or identical parts.

Detailed Description

For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to the examples illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the claims is thereby intended. Modifications in the illustrated examples, and such further applications of the principles of the disclosure as illustrated herein are contemplated as would normally occur to one skilled in the art to which the disclosure relates.

Increasing productivity is a common desire of welding operators and management personnel, and therefore, productivity improvement in welding manufacturing is beneficial. The improvement in welding operator efficiency may improve overall production efficiency, reduce the impact of skilled welding labor shortages, shorten project schedules, and/or reduce project costs associated with welding.

The disclosed example systems and methods include a preheating system to preheat welding wire (e.g., wire electrode) that has been shown to have characteristics that significantly increase deposition when applied to open arc welding wire robotic welding processes. However, in many welding applications, welding performed by a worker's hand is much more common than robotic welding. Even if the welding operator has limitations in deposition and productivity, hand-held welding can enjoy the same benefits of wire preheating as robotic welding. In robotic applications, the travel speed required to maximize productivity using wire preheating is achievable for robots. However, in handheld applications, a human welding operator may not be able to travel fast enough within the joint configuration required for a given welding task to achieve acceptable welding conditions.

The disclosed example systems and methods provide some operator interface techniques to allow an operator holding a welding torch to easily, intuitively, and cooperatively control welding and preheating parameters during a welding operation. Some examples provide an operator with the ability to adjust welding and/or preheating parameters on-the-fly during a welding operation, such as allowing the operator to switch from a first set of welding parameters involving preheating a wire electrode to a conventional welding wire process that does not involve preheating (or vice versa) via an interface on a welding torch and/or on another welding accessory. For example, for situations where the operator is ergonomically able to provide higher travel speeds, such as long welds, flat welds, level welds, preheating may be used (e.g., at full or reduced output). For other welds, such as vertically up, vertically down, welds around corners, and/or other out-of-position welds, the disclosed examples enable disabling pre-heating power to accomplish such welds using conventional welding parameters.

In an example of operation of the disclosed systems and methods, a welding operator or welding engineer may establish and store one or more welding protocols, or a predetermined set of welding and preheating parameters, on a welding power source and/or a welding accessory (e.g., a wire feeder). In some examples, the welding power source or the welding accessory automatically calculates and stores an accompanying welding profile based on a programmed welding profile. For example, when a welding operator or welding engineer programs a first welding profile (e.g., welding voltage, wire feed speed, etc.) based on a given material thickness, wire diameter, wire type, gas type, and/or any other factors that control welding parameters, the control circuitry of the welding power supply or welding accessory may automatically calculate and store one or more additional welding profiles in which the welding parameters set for the welding profile by the welding engineer or welding operator are adjusted and for which the wire preheat power is increased to improve deposition, reduce hydrogen in the wire and/or final weldment, and/or achieve other benefits of wire preheat.

When the welding operator desires to recall the stored welding profile, the operator may select the stored welding profile via an input device on the welding torch, or via an interface on the welding power supply or welding accessory. For example, a welding operator may select a first welding profile (e.g., a companion welding profile) that provides higher deposition and/or other wire preheating benefits (e.g., by allowing wire preheating) for one or more first welding operations in which the welding operator is able to perform a travel speed (e.g., a straight weld) suitable for higher deposition rates. The welding operator may select a second welding profile (e.g., a welding profile programmed by the welding operator or welding engineer) that does not include wire preheating for welding operations where it is more difficult to reliably achieve higher travel speeds. In this manner, the welding operator may quickly alternate between stored welding protocols and increase productivity.

Some example systems and methods further enable coordinated control of welding parameters and preheating parameters during welding and/or when not welding. For example, the operator may be provided with a coordinated input device that enables the operator to control two or more parameters from the torch, such as by modifying the pressure on the trigger. As used herein, the term "coordinated control" refers to the simultaneous control of two or more welding-related parameters or variables, such as the control of one or more parameters or variables based on a change in another parameter or variable. As used herein, "coordinated output" refers to welding and/or preheating power that: wherein two or more variables associated with generating welding and/or preheating power are controlled according to a particular relationship. Coordinated control may be achieved using a single user input device. Analog signals or encoded digital signals are output from a coordinated input device (e.g., trigger), and the disclosed systems and methods control the welding and/or preheating output based on the value of the signal (e.g., within a predetermined range of values). In some examples, the coordinated input device may be configured by the operator to correspond to intuitive results such as heat input (e.g., increasing heat input by further depressing the trigger or decreasing heat input by decreasing pressure on the trigger), deposition, weld penetration depth, weld/preheat balance, and/or any other result. The disclosed example systems and methods automatically adjust welding parameters and/or preheating parameters based on values of the signals.

As used herein, the word "exemplary" means "serving as an example, instance, or illustration. The embodiments described herein are not limiting, but rather are exemplary only. It is to be understood that the described embodiments are not necessarily to be construed as preferred or advantageous over other embodiments. Moreover, the terms "embodiments of the invention," "embodiments," or "invention" do not require that all embodiments of the invention include the discussed feature, advantage, or mode of operation.

As used herein, the terms "circuit" and "circuitry" refer to physical electronic components (i.e., hardware) as well as any software and/or firmware (code) that may configure, be executed by, and/or otherwise associated with the hardware. As used herein, for example, a particular processor and memory may constitute a first "circuit" when executing a first set of one or more lines of code, and may constitute a second "circuit" when executing a second set of one or more lines of second code. As used herein, "and/or" refers to any one or more of the items in the list connected by "and/or". For example, "x and/or y" refers to any element in the three-element set { (x), (y), (x, y) }. In other words, "x and/or y" means "one or both of x and y". As another example, "x, y, and/or z" refers to any element of the seven-element set { (x), (y), (z), (x, y), (x, z), (y, z), (x, y, z) }. In other words, "x, y, and/or z" means "one or more of x, y, and z. As used herein, the term "exemplary" means serving as a non-limiting example, instance, or illustration. As used herein, the terms "for example" and "such as" give a list of one or more examples, instances, or illustrations. As used herein, circuitry is "operable" to perform a function whenever the circuitry includes the necessary hardware and code (if necessary) to perform that function, regardless of whether the performance of that function is disabled or not enabled (e.g., by operator-configurable settings, factory adjustments, etc.).

As used herein, a wire-feed welding-type system refers to a system capable of performing welding (e.g., Gas Metal Arc Welding (GMAW), Gas Tungsten Arc Welding (GTAW), Submerged Arc Welding (SAW), etc.), brazing, cladding, hardfacing, and/or other processes in which a filler metal is provided by a wire fed into a work location, such as an arc or weld puddle.

As used herein, a welding-type power supply refers to any device capable of powering welding, cladding, plasma cutting, induction heating, laser machining (including laser welding and laser cladding), carbon arc cutting or scraping, and/or resistive preheating when power is applied, including, but not limited to, transformers-rectifiers, inverters, converters, resonant power supplies, quasi-resonant power supplies, switch-mode power supplies, and the like, as well as control circuitry and other ancillary circuitry associated therewith.

As used herein, preheating refers to heating the wire electrode prior to welding arc and/or deposition on the wire electrode's travel path.

Some disclosed examples describe current being "conducted from" and/or "to" multiple locations in a circuit and/or power supply. Similarly, some disclosed examples describe "providing" current via one or more paths, which may include one or more conductive elements or partially conductive elements. The terms "from," "to," and "providing" used to describe current conduction do not require the direction or polarity of the current. Conversely, even if example current polarities or directions are provided or illustrated, these currents may be conducted in either direction or with either polarity for a given circuit.

FIG. 1 illustrates an example welding system 10 configured to deliver welding-type power to a welding accessory, such as a pre-heated wire feeder 16, for conversion to welding-type output power and resistive pre-heating power. The exemplary welding system 10 of FIG. 1 includes a welding power supply 12 and a preheat torch 14. The welding torch 14 may be a welding torch configured for any wire-feed welding process, such as Gas Metal Arc Welding (GMAW), Flux Core Arc Welding (FCAW), and/or Submerged Arc Welding (SAW), based on the desired welding application.

The welding power supply 12 supplies welding-type power to a pre-heating wire feeder 16, which converts input welding-type power to one or both of output welding-type power and/or resistive pre-heating power that is output to the welding torch 14. The pre-heated wire feeder 16 also supplies filler metal to a welding torch 14 configured for GMAW welding, FCAW welding, or SAW welding.

The welding power supply 12 is coupled to a primary power source 22, such as an electrical grid or an internal combustion engine driven generator, which supplies primary power, which may be single phase or three phase AC power. The welding power supply 12 may process the primary power to output welding-type power for output to the welding torch 14 or the wire feeder 16 via the power cable 24. In some examples, the power cable 24 includes a plurality of terminals, with one terminal having a positive polarity and the other terminal having a negative polarity. The power conversion circuitry 30 converts the main (e.g., AC) current to welding-type power, which is either Direct Current (DC) or AC. The power conversion circuitry 30 may include circuit elements such as transformers, switches, boost converters, inverters, etc., which are capable of converting power as required by the welding system 10. In some embodiments, the power conversion circuitry 30 is configured to convert the primary power to substantially 80V DC welding-type power to power the preheat wire feeder 16. Such an example input power may be between about 50V to 120V DC.

The welding power supply 12 includes control circuitry 32 and an operator interface 34. The control circuitry 32 controls operation of the welding power supply 12 and may receive input from an operator interface 34 through which an operator may select a welding process (e.g., GMAW, FCAW, SAW) and input desired input power parameters (e.g., voltage, current, particular pulsed or non-pulsed welding regime, etc.). The control circuitry 32 may be configured to receive and process a number of inputs regarding the performance and requirements of the system 10.

The welding power supply 12 may include polarity reversal circuitry 36 and communication circuitry 38 coupled to the control circuitry 32. The polarity reversing circuit 36 reverses the polarity of the output welding-type power when directed by the control circuit 32. For example, some welding processes, such as TIG welding, may achieve a desired weld when the electrodes have a negative polarity (referred to as DC reverse connection) (DCEN). Other welding processes, such as stick welding or GMAW welding, may achieve the desired weld when the electrodes have a positive polarity (referred to as DC positive connection) (DCEP). When switching between the TIG welding process and the GMAW welding process, the polarity reversing circuitry 36 may be configured to convert the polarity from DCEN to DCEP. Additionally or alternatively, the operator may simply connect the terminals of the cable 24 to the preheat wire feeder 16 without knowledge of the polarity, such as when the terminals are located at a substantial distance from the power source 12. The control circuitry 32 may direct the polarity inversion circuitry 36 to invert the polarity in response to signals received through the communication circuitry 38.

In some examples, the communication circuitry 38 is configured to communicate with the welding torch 14, the preheating wire feeder 16, and/or other device(s) coupled to the power cable 24. The communication circuitry 38 sends and receives command and/or feedback signals over the welding power cable 24 for supplying welding-type power. Additionally or alternatively, the communication circuitry 38 communicates wirelessly with the welding torch 14, the preheating wire feeder 16, and/or other device(s).

For some welding processes (e.g., GMAW), a shielding gas is utilized during the welding process. In the example of fig. 1, the welding power supply 12 includes one or more gas control valves 46 configured to control a flow of gas from a gas source 48. The control circuitry 32 controls the gas control valve 46. The welding power supply 12 may be coupled to one or more gas sources 48 because, for example, some welding processes may utilize a different shielding gas than other welding processes. In some examples, the welding power supply 12 is configured to supply gas with input power via a combined input cable 50 (e.g., including conductors housed in the cable 24). In other examples, the gas control valve 46 and the gas source 48 may be separate from the welding power supply 12. For example, the gas control valve 46 may be disposed within the preheat wire feeder 16, as described below with reference to fig. 2.

The preheat wire feeder 16 receives welding-type power as input via input terminals configured to couple with terminals of the power cable 24. The example pre-heating wire feeder 16 of fig. 1 is coupled to a pre-heating GMAW welding torch 14 configured to supply gas, wire electrode 54, and electrical power to a welding application. As discussed in more detail below, the preheat wire feeder 16 is configured to receive input welding-type power from the power source 12, convert a first portion of the input welding-type power to second welding-type power and output the second welding-type power to the welding circuit, convert a second portion of the input welding-type power to preheat power and output the preheat power to the preheat circuit.

The example welding torch 14 includes a first contact tip 18 and a second contact tip 20. The wire electrode 54 is fed from the pre-heat wire feeder 16 to the welding torch 14 and through the contact tips 18, 20 to generate the welding arc 26 between the wire electrode 54 and the workpiece 44. The preheat circuit includes the first contact tip 18, the second contact tip 20, and a portion of the wire electrode 54 between the first contact tip 18 and the second contact tip 20. The example preheat wire feeder 16 is further coupled to a work cable 42 that is coupled to a workpiece 44.

In operation, the wire electrode 54 passes through the second contact tip 20 and the first contact tip 18, between which the preheating wire feeder 16 outputs a preheating current to heat the wire electrode 54. Specifically, in the configuration shown in fig. 1, the preheat current enters the wire electrode 54 via the second contact tip 20 and exits via the first contact tip 18. However, the preheat current may be conducted in the opposite direction. At the first contact tip 18, welding current may also enter (or exit) the wire electrode 54. The welding current is output by a pre-heated wire feeder 16, which derives pre-heating power and welding-type power from the welding-type power supplied by the power supply 12. The welding current exits the wire electrode 54 via the workpiece 44, thereby generating the welding arc 26. When the wire electrode 54 contacts the workpiece 44, the circuit is completed and welding current flows through the wire electrode 54, through the metal workpiece(s) 44, and back to the preheating wire feeder 16. The welding current melts the parent metal of the wire electrode 54 and the workpiece(s) 44 in contact with the wire electrode 54, thereby engaging the workpieces as the melt solidifies. By preheating the wire electrode 54, the resulting welding arc 26 may have a substantially reduced arc energy. Generally, the preheating current is inversely proportional to the distance between the contact tips 18, 20 and/or directly proportional to the wire electrode 54 diameter.

Fig. 2 is a block diagram of an example implementation of the preheating wire feeder 16 of fig. 1. The example preheat wire feeder 16 receives welding-type power as input and converts the welding-type power to welding-type power and/or preheat power. For example, the pre-heat wire feeder 16 may output welding-type power and pre-heat power simultaneously, alternately, and/or only one of welding-type power or pre-heat power at a given time, depending on the welding task and/or the experience of the operator.

The preheat wire feeder 16 receives input power from the welding power supply 12 of fig. 1 via input terminals 40 coupled to control circuitry 56. The pre-heated wire feeder 16 may be operated remotely from the welding power supply 12 via a relatively long cable coupling the pre-heated wire feeder 16 to the welding power supply 12.

The control circuitry 56 includes one or more controllers and/or processors 82 that control operation of the preheating wire feeder 16. Control circuitry 56 receives and processes a number of inputs associated with the performance and requirements of the system. Processor(s) 82 may include one or more microprocessors, such as one or more "general purpose" microprocessors, one or more special purpose microprocessors and/or ASICS, one or more microcontrollers, and/or any other type of processing and/or logic device. For example, the control circuitry 56 may include one or more Digital Signal Processors (DSPs). The control circuitry 56 may include circuitry such as relay circuitry, voltage and current sensing circuitry, power storage circuitry, and/or other circuitry, and is configured to sense input power received by the preheat wire feeder 16.

The example control circuitry 56 includes one or more memory devices 84. The memory device(s) 84 may include volatile and/or non-volatile memory and/or storage devices such as Random Access Memory (RAM), Read Only Memory (ROM), flash memory, hard drives, solid state storage devices, and/or any other suitable optical, magnetic, and/or solid state storage media. The memory device(s) 84 store data (e.g., data corresponding to a welding application), instructions (e.g., software or firmware for performing a welding process), and/or any other suitable data. Examples of stored data for welding applications include the attitude (e.g., orientation) of the welding torch, the distance between the contact tip and the workpiece, voltage, current, welding device settings, and so forth. For example, the memory device 84 may store machine-executable instructions (e.g., firmware or software) for execution by the processor 82. Additionally or alternatively, one or more control schemes for different welding processes are stored in the memory device(s) 84 along with associated settings and parameters, along with machine-executable instructions configured to provide specific outputs during operation (e.g., start wire feed, enable gas flow, capture welding current data, detect short circuit parameters, determine amount of spatter).

The preheat wire feeder 16 further includes power conversion circuitry 58. The power conversion circuitry 58 is configured to convert a first portion of the input welding-type power to a second welding-type power and to convert a second portion of the input welding-type power to pre-heating power. The first and second portions of the input welding-type power may be divided in time (e.g., the first portion is used at a first time and the second portion is used at a second time) and/or divided into a portion of the total delivered power at a given time. The power conversion circuitry 58 outputs the second welding-type power to the welding circuit and outputs the preheat power to the preheat circuit. The welding torch 14 may be used to implement both a welding circuit and a preheating circuit.

The power conversion circuitry 58 may include circuit elements such as boost converters, buck converters, half-bridge converters, full-bridge converters, forward converters, flyback converters, internal buses, bus capacitors, voltage and current sensors, and/or any other topology and/or circuitry for converting input power to and outputting welding power and preheat power to the welding torch 14. In some examples, the input power received by the preheating wire feeder 16 is a DC voltage between approximately 20V to 120V, approximately 40V to 100V, or approximately 60V to 80V. As used with reference to input power, the term "approximately" may refer to within ± 5 volts or within 10% of a required voltage.

The power conversion circuitry 58 may be configured to convert the input power to any conventional and/or future welding-type output. The example power conversion circuitry 58 may implement one or more controlled voltage control loops and/or one or more controlled current control loops for controlling the voltage and/or current output to the welding circuit and/or the preheat circuit. As described in more detail below, the power conversion circuitry 58 may be implemented using one or more conversion circuits, such as a plurality of conversion circuits, wherein a single conversion circuit is used to generate each of the welding-type output and the preheat output.

In some examples, the power conversion circuitry 58 is configured to convert the input power to a controlled waveform welding output, such as a pulse welding process or a short circuit welding process (e.g., deposited metal control technology (RMDTM)). The power conversion circuitry 58 disposed within the preheated wire feeder 16 supplies a controlled waveform welding output for a welding application without attenuation from the power cable between the welding power source and the preheated wire feeder 16. This increases the response time and accuracy of the controlled waveform welding output supplied to the torch. Increasing the response time of the controlled waveform welding output may ensure that the desired welding output waveform is supplied to the welding torch at a particular time during welding. For example, the RMDTM welding process utilizes a controlled waveform welding output whose current waveform changes at a particular point in time within a short circuit period. Increasing the response time of the controlled waveform welding output may also improve the timing of the waveform pulses to produce the desired weld.

In some examples, the power conversion circuitry 58 is configured to provide welding output to the wire feed assembly 60. The wire feed assembly 60 supplies the wire electrode 54 to the welding torch for the welding operation. Wire feed assembly 60 includes components such as a wire spool 64 and a wire feed drive configured to power a drive roll 68. The wire feed assembly 60 feeds the wire electrode 54 along a weld cable 62 to the torch. The welding output may be supplied via a welding cable 62 coupled to the welding torch and/or a work cable 42 coupled to the workpiece 44.

The example pre-heat wire feeder 16 includes a user interface 66 for controlling parameters of the welding system 10. The user interface 66 is coupled to the control circuitry 56 to enable an operator to select and adjust the welding process (e.g., pulse, short, FCAW) by selecting wire size, wire type, material, and gas parameters. The user interface 66 is coupled to the control circuitry 56 for controlling voltage, amperage, wire feed speed, and arc length for the welding application. The user interface 66 may receive input using any input device, such as via a keypad, keyboard, buttons, touch screen, voice activated system, wireless device, or the like.

The user interface 66 may receive input specifying a wire material (e.g., steel, aluminum), a wire type (e.g., solid, flux core), a wire diameter, a gas type, and/or any other parameter. Upon receiving the input, the control circuitry 56 determines a welding output for the welding application. For example, the control circuitry 56 may determine a welding voltage, a welding current, a wire feed speed, an inductance, a welding pulse width, a relative pulse amplitude, a waveform, a preheat voltage, a preheat current, a preheat pulse, a preheat resistance, a preheat energy input, and/or any other welding and/or preheat parameter for the welding process based, at least in part, on input received via the user interface 66.

The exemplary preheating wire feeder 16 further includes communication circuitry 70 coupled to the control circuitry 56 to send and receive command and/or feedback signals over the power cable for providing input power to the preheating wire feeder. The communication circuitry 70 may further enable the user interface 66 to control the welding power supply. For example, the user interface 66 may be configured to control the amperage, voltage, or other parameters of the input power supplied by the welding power supply 12. In some examples, the control circuitry 56 controls the welding power supply 12 from a location remote from the welding power supply 12 and is limited to setting parameters on the operator interface 34 (fig. 1). That is, the control circuitry 56 and communication circuitry 70 enable an operator to remotely control the welding power supply 12 by preheating the wire feeder 16 at the same control priority as the operator interface 34 of the welding power supply.

The communication circuitry 70 may communicate data to other devices in the system 10 of fig. 1 via a wireless connection. Additionally or alternatively, the communication circuitry 70 communicates with other welding devices using one or more wired connections, such as by using a Network Interface Controller (NIC), to communicate data via a network (e.g., ethernet, 10base t, 10base100, etc.), and/or to communicate via the terminal 40 that receives welding-type input power. An example implementation of the communication circuitry 70 is described in U.S. patent No. 9,012,807. U.S. patent No. 9,012,807 is incorporated herein by reference in its entirety. However, other implementations of the communication circuitry 70 may be used.

In the example wire feeder 16 shown, a valve assembly 72 is included, the valve assembly 72 being used to provide gas to the welding torch 14 along a gas line 74. The valve assembly 72 may be controlled by the control circuitry 56. For example, the valve assembly 72 may be configured to supply gas to the welding torch 14 before and after a welding task. In some examples, the valve assembly 72 is configured to purge the gas line 74 upon receiving a purge command from the user interface 66.

During operation, the power conversion circuitry 58 establishes a welding circuit to conduct welding current from the power conversion circuitry 58 to the first contact tip 18 and back to the power conversion circuitry 58 via the welding arc 26, the workpiece 44, and the work cable 42.

During operation, the power conversion circuit 58 establishes a preheat circuit to conduct a preheat current through the section 102 of the wire electrode 54. The preheat current flows from the power conversion circuitry 58 to the second contact terminal 20 via the first cable 106, through the section 102 of the electrode wire 54 to the first contact terminal 18, and back to the power conversion circuitry 58 via the second cable 104 connecting the power conversion circuitry 58 to the first contact terminal 18. Either, both, or neither of the cables 104, 106 may be combined with other cables and/or conduits. For example, cable 104 and/or cable 106 may be part of cable 62. In other examples, the cable 106 is included within the cable 62 and the cable 104 leads solely to the welding torch 14. To this end, the preheat wire feeder 16 may include one to three terminals to which one or more cables may be physically connected to establish a preheat connection, a weld connection, and a work piece connection. For example, suitable insulating structures may be used between different connections to enable multiple connections in a single terminal.

Because the preheat current path overlaps the solder current path at the connection between the first contact tip 18 and the power conversion circuitry 58 (e.g., via the cable 104), the cable 104 may enable a more cost-effective single connection (e.g., a single cable) between the first contact tip 18 and the power conversion circuitry 58 rather than providing separate connections for the solder current to the first contact tip 18 and the preheat current to the first contact tip 18.

The exemplary preheating wire feeder 16 includes a housing 86 within which the control circuitry 56, the power conversion circuitry 58, the wire feed assembly 60, the user interface 66, the communication circuitry 70, and/or the valve assembly 72 are housed. In examples where the power conversion circuitry 58 includes multiple power conversion circuits (e.g., a preheat power conversion circuit and a weld power conversion circuit), all of the power conversion is performed in the housing 86.

In some other examples, instead of providing welding-type power directly to the preheating wire feeder 16 via two conductors as in the example system 10 of fig. 1, the example preheating wire feeder 16 is coupled to the power source 12 via one conductor (e.g., via a positive connection or a negative connection) in a manner similar to a conventional voltage sensing wire feeder. The power source 12 is coupled to the workpiece 44 via a work cable to complete the welding circuit. To provide communication, voltage sensing, and/or preheating power, the preheating wire feeder is also coupled to the workpiece 44 via a voltage sensing lead. Because the voltage sense lead is not part of the welding circuit and does not conduct welding current, the voltage sense lead may be designed to conduct less current than the work cable 42. However, the voltage sense leads are configured to withstand sufficient current to provide power to the preheat power conversion circuitry, communication circuitry, control circuitry, and/or wire feed hardware. The exemplary preheat wire feeder 16 converts at least a portion of the power received from the power source 12 to preheat power. The pre-heating wire feeder 16 outputs pre-heating power to the first and second contact tips 18, 20 via a conductor, and is further configured to transfer welding-type power to the first contact tip 18 via a conductor and/or a separate conductor and/or cable to generate a welding arc 26. One or more conductors carrying the preheating and/or welding current may be incorporated into a cable having a wire liner guiding the wire electrode 54 and/or having a gas line conducting shielding gas to the welding torch 14.

In the example of fig. 1 and 2, the example welding torch 14 includes power selector circuitry 52 to allow a user of the welding torch (e.g., a welder) to adjust the welding output and/or the preheating output from the welding torch 14 in a coordinated manner. For example, the power source 12 and the wire feeder 16 cooperate to vary the welding output power (e.g., welding output voltage, arc voltage, welding current, etc.), the preheating power (e.g., preheating voltage, preheating current, target wire temperature, preheating input, target wire resistance, etc.), and/or the wire feed speed of the weld as adjusted by the user via the power selector circuitry 52.

An example implementation of power selector circuitry 52 is a pressure sensitive trigger. For example, the welding torch 14 may include the same trigger as used in conventional welding-type torches modified to provide an analog signal or a coded digital signal to represent the amount of input to the trigger. In some examples, the operator may gradually depress the trigger (e.g., apply more and more pressure) to change the balance between welding power and pre-heating power, thereby increasing the total power applied to the weld and/or increasing the deposition rate; and/or gradually releasing the trigger (e.g., applying less and less pressure) to change the balance between welding power and pre-heating power, thereby reducing the overall power applied to the weld and/or reducing the deposition rate. Alternative implementations of power selector circuitry 52 include wheels, dials, knobs, foot pedals, slides, and/or any other input device that generates a signal (e.g., via an encoder, potentiometer, etc.) that is configured to output a signal and positioned to enable an operator to manipulate the input while welding (e.g., while holding a trigger).

The power selector circuitry 52 outputs control signals to the control circuitry 32 of the power source 12 (e.g., via the communication circuitry 38) and/or to the control circuitry 56 of the wire feeder 16 (e.g., via one or more cables 104, 106 and/or via the wire electrode 54, or via a separate control cable). The control signal may be an analog signal or a digital signal representing the output from power selector circuitry 52. The control circuitry 32 identifies user inputs (e.g., inputs from the power selector circuitry 52) during welding-type operations involving welding-type power and/or pre-heating power. The control circuitry 32 determines a voltage adjustment for the welding-type power, an adjustment for the preheat power, and/or a wire feed speed adjustment based on the user input. For example, the control circuitry 32 may reference a coordinated control scheme, such as an algorithm or a look-up table, to determine a voltage set point, a preheat set point, and/or a wire feed speed set point corresponding to the user input. The look-up table may be stored, for example, in memory 84 of control circuitry 56 and/or similar memory or storage devices of control circuitry 32.

The example control circuitry 56 and/or communication circuitry 70 of the wire feeder 16 may generate one or more control signals to control the welding power supply 12 to perform output adjustments (e.g., to change the power input to the wire feeder 16), to control the power conversion circuitry 58 to modify the welding-type power and/or the pre-heat power output to the welding torch 14, and to control the wire feed assembly 60 to perform wire feed speed adjustments.

A user may select (e.g., via operator interface 34, user interface 66, and/or power selector circuitry 52) from a plurality of coordinated control schemes that may be controlled via power selector circuitry 52. An example coordinated control scheme includes controlling a balance between welding output and preheating output from the power conversion circuitry 58 based on a control signal from the power selector circuitry 52 while maintaining a constant target heat input to the weld. For example, the control circuitry 56 may control the power conversion circuitry 58 to increase the welding output and decrease the pre-heat output in response to an increase (or decrease) in pressure on the trigger, and control the power conversion circuitry 58 to decrease the welding output and increase the pre-heat output in response to an increase (or decrease) in pressure on the trigger. Changing the balance of welding power and preheating power while maintaining consistent heat input may, for example, change the penetration depth and/or deposition rate of the weld. For example, the control balance may be configured to: increasing the trigger pressure increases the rate of deposition or increases the rate of penetration, whereby the operator may consider using the trigger to control a result-based parameter (e.g., the rate of penetration or deposition).

Another example coordinated control scheme that may be selected includes controlling the welding output and the preheating output to increase or decrease the heat input to the weld in response to changes in the signal from the power selector circuitry 52. For example, when the operator increases the pressure on the trigger (or manipulates another input device), the control circuitry 32 controls the power conversion circuitry 58 to increase the pre-heat output, the weld output, and/or the wire feed speed, thereby increasing the heat input to the weld. Conversely, when the operator decreases the pressure on the trigger (or manipulates another input device), the control circuitry 32 controls the power conversion circuitry 58 to decrease the pre-heat output, the weld output, and/or the wire feed speed, thereby decreasing the heat input to the weld.

In some examples, coordinated control of the voltage and wire feed speed causes the control circuitry 32 to change the cladding mode in response to user input via the power selector circuitry 52. For example, GMAW deposit modes (such as no arc hot wire mode, metal deposit control mode, controlled short circuit mode, short arc mode, pulsed spray mode, or spray transfer mode) typically correspond to different voltage ranges (with some overlap between some modes).

In some examples, the control circuitry 32 implements a trigger hold feature that enables an operator to set a particular coordinated output (e.g., a welding output and/or a preheat output). When the trigger hold is enabled, the operator may release the power selector circuitry 52 (e.g., causing the normalized value of the control signal to drop below a threshold associated with outputting welding-type power), and the control circuitry 32 continues to maintain the coordinated output using the held value of the control signal 28. In some examples, trigger hold is enabled after a substantially constant output (e.g., less than a threshold deviation) for a threshold period of time. Additionally or alternatively, the welding torch 14, the wire feeder 16, and/or any other device may include an input device (e.g., a button, a switch, etc.) that provides a control signal hold command to the control circuitry 32. When a trigger hold is enabled, such as when the operator releases power selector circuitry 52, control circuitry 32 determines the appropriate coordinated output and controls power conversion circuitry 30 and wire feeder 104 based on the hold value determined in association with the control signal hold command. For example, the hold value may be determined to be a value at which the operator holds the power selector circuitry 52 for a threshold period of time to generate the control signal hold command and/or the hold value is the value of the control signal 28 at the time the control signal hold command is generated.

In response to the operator not using the trigger hold function for a threshold period of time, the control circuitry 32 may timeout the trigger hold feature and disable the trigger hold feature. For example, if the operator is unaware that a trigger holding feature is available or ready, the operator may not intend to continue performing a welding-type operation in response to releasing the trigger of the welding torch 14. In other cases, the operator may not want to use the trigger hold, and may prefer to continue using (e.g., changing) the coordinated output during a welding-type operation.

In some examples, control circuitry 32 responds to the control signal hold command by outputting a perceptible warning to inform the operator that a trigger hold may be enabled (e.g., when power selector circuitry 52 is released). Example alerts may include visual alerts, audible alerts, tactile alerts, and/or any other type of perceptible feedback. Example trigger hold feedback may include, for example, an audible signal (e.g., a beep, tone, audible message, and/or any other audible feedback via the power supply 12, the wire feeder 104, the welding torch 14, a speaker in the operator's helmet, and/or any other speaker), a visual signal (e.g., a light, an LED, a display, and/or any other visual feedback via the power supply 12, the wire feeder 16, the welding torch 14, the operator's helmet, and/or any other visual device), a tactile feedback (e.g., a tactile or other tactile feedback at the welding torch 14 or at other locations that the operator may perceive), and/or any other form of feedback. If the operator chooses to use the trigger hold function (e.g., by releasing the trigger or other variable input device), the trigger hold feedback signal informs the operator that the trigger hold function has been enabled at the current coordinated output level. In some examples, the welding torch 14 includes a haptic generator 108 (such as a vibration motor, an eccentric rotating mass actuator, a piezoelectric actuator, and/or any other type of haptic generator) to generate haptic feedback to the operator, and the control circuitry 32 is configured to output a haptic feedback signal to control the vibration motor in response to the control signal hold command.

In some examples, the control circuitry 32 may generate a feedback control signal during the welding operation to alert an operator to the occurrence of one or more events. The feedback control signals may be used to control devices internal to the power supply 12 (e.g., a display of the operator interface 34, a speaker of the operator interface 34, etc.) and/or external to the power supply 12 (e.g., devices in an operator's helmet, a display at the user interface 66, a display on the welding torch 14, a display on the wire feeder 16, etc.). Example events are associated with coordinated control by an operator, such as alerting the operator when the value of the control signal 28 is outside a predetermined range or window of values. The predetermined range of values may be defined by an operator and/or determined by the control circuitry 32 using welding parameters (e.g., physical parameters of the weld, etc.), preheating parameters (e.g., distance between the contact tips 18, 20, diameter of the welding wire 54, material of the welding wire 54, target preheating temperature or enthalpy, etc.), Welding Process Specifications (WPS), and/or any other information.

Other example events associated with coordinated control include feedback representing values of the control signal 28 and/or coordinated outputs (e.g., power, voltage, and/or wire feed speed). For example, the control circuitry 32 may control the haptic generator 108 to increase the intensity and/or frequency of the haptic feedback in proportion to (or in inverse proportion to) the control signal and/or the coordinated output, change the haptic feedback mode based on a characteristic of the coordinated output (e.g., deposition mode, whether the control signal is within a sub-range of the input value range, etc.). Additionally or alternatively, the control circuitry 32 may output audio that is increased in amplitude, frequency, and/or any other characteristic based on the value of the control signal and/or the coordinated output. The audio-based output may be, for example, a speaker or buzzer on the power supply 12, the wire feeder 16, the welding torch 14, a helmet worn by the operator, and/or a separate device. Additionally or alternatively, the control circuitry 32 may output the audio feedback using Arc-based audio, using techniques such as those disclosed in U.S. patent publication No. 2019/0015920(Knoener et al) entitled "method and Apparatus for communicating through a welding Arc," filed on 12.7.2017. U.S. patent publication No. 2019/0015920 is incorporated herein by reference in its entirety.

In some examples, the control circuitry 32 controls visual feedback (e.g., LEDs, flash lights, graphics on the display 116, etc.) that changes in color, graphics, flash frequency, and/or any other visual feedback technique. For example, the control circuitry 32 may update a graphic on the display 116 that shows a range of values of the control signal 28 and/or coordinated outputs (e.g., power, voltage, and/or wire feed speed). The range may specify upper and lower limits for the coordinated output and/or a range of input values for the control signal 28, and an indicator is displayed that graphically illustrates the current input signal or the coordinated output. The range may be based on, for example, physical characteristics of the welding operation, an operator selected range, and/or any other variable.

In other examples, the control circuitry 32 may output the feedback control signal in response to a change in control of the coordinated output (such as when changing from a first sub-range of the range of input values to a second sub-range of the range of input values, when changing the cladding mode), and/or any other change that may be implemented by the operator using the power selector circuitry 52. For example, if the operator decreases the pressure on the trigger to decrease the coordinated output, the control circuitry 32 may generate a feedback control signal in response to the control signal 28 crossing a threshold point indicative of a change in control (e.g., a threshold of the control signal 28).

The example control circuitry 32 may also filter the control signal 28 to avoid unexpected variations in the coordinated output due to difficulties in maintaining the power selector circuitry 52 in a stable position. For example, the control circuitry 32 may filter the control signal 28 to reduce the effects of short term or transient variations in the coordinated output. An example filtering technique may include determining a coordinated output using a set of recent samples of the control signal 28 and applying a weight to the samples of the control signal 28 based on the time duration of the samples. Thus, older samples are weighted more heavily in determining the collaborative output than newer samples. In some such examples, after a threshold duration of a sample, the weights may have a rapid increase such that sample weights previously measured to be less than the threshold time are very low, while sample weights previously measured to be greater than the threshold time are significantly greater.

Another example technique that may be used includes determining a filtered subrange of the value of the control signal 28 based on the value of the control signal 28 at a given time. When the value of the control signal 28 remains within the filtered sub-range of values at a subsequent time, the control circuitry 32 cooperatively controls the voltage and wire feed speed of the welding-type power supply based on the value of the control signal 28 used to determine the filtered sub-range.

In some examples, the control circuitry 32 maps a range or sub-range of values of the control signal 28 to the entire range of output power that the welding-type system 10 is capable of achieving. In other examples, the range of values of the control signal 28 is mapped to a sub-range of the coordinated output and/or a sub-range of variables (e.g., voltage and wire feed speed) involved in generating the coordinated output. For example, the control circuitry 32 may determine the recommended range and/or the allowable range of the synergic output based on physical characteristics of the welding operation and/or preheating characteristics of the welding operation. The physical characteristics of the welding operation and/or the preheating characteristics may be input via operator interface 34. Based on the determined range, the control circuitry 32 maps the recommended range and/or the allowed range of the collaborative output to a range of values of the control signal 28 such that the collaborative output cannot exceed the mapped sub-range of the collaborative output. Example physical characteristics that may be used to determine a subrange of the synergistic output may include a workpiece thickness, a workpiece material, a wire composition, a wire diameter, and/or a shielding gas composition. Example preheating characteristics that may be used to determine a sub-range of coordinated output may include a preheating distance (e.g., distance of section 102 between contact tips 18, 20), a diameter of wire 54, a material of wire 54, a target preheating temperature or enthalpy, and/or a balance between welding power and preheating power. By mapping the range of values of the control signal 28 to a sub-range determined to be recommended or allowed for the physical and/or preheating characteristics of the weld operation, an operator may be prevented from using a coordinated output that is not recommended for the particular physical and/or preheating characteristics of the weld, thereby improving weld quality and reducing errors and/or rework.

Additionally or alternatively, the control circuitry 32 may map a sub-range of the control signal 28 to a separate sub-range of the coordinated output, where the sub-range of the control signal 28 is not equally wide and/or the sub-range of the coordinated output is not equally wide. In this manner, the control circuitry 32 may enable the operator to have a higher degree of control over the coordinated output in a portion of the range of power selector circuitry 52 of interest (e.g., a portion of the range of travel of the trigger or foot pedal) than in another portion.

In some examples, the power selector circuitry 52 enables selection of one or more welding protocols, or a predefined set of parameters. The example welding profile may be configured via operator interface 34 and/or user interface 66 to specify any combination of welding and/or preheating parameters and recalled via power selector circuitry 52. For example, the power selector circuitry 52 may include a selection button to switch between two or more welding schemes, or may change a welding scheme in response to a predetermined input via a trigger (e.g., a trigger pull lasting less than a threshold time). Example parameters that may be specified as part of a welding protocol include welding voltage, wire feed speed, welding current, heat input, preheating voltage, preheating current, preheating resistance, preheating power, preheating heat input, pulse parameters, advanced waveform control, AC balance, AC frequency, material thickness, wire type, and/or any other desired parameter.

The example control circuitry 32, 56 may automatically calculate and store an accompanying welding profile based on the programmed welding profile. For example, when a first welding profile (e.g., welding voltage, wire feed speed, etc.) is input into the control circuitry (e.g., via the operator interface 34 or the user interface 66), the control circuitry 32, 56 automatically calculates and stores one or more additional companion welding profiles. For example, a welding operator or welding engineer may program the first welding profile based on a given material thickness, wire diameter, wire type, gas type, and/or any other factors that control welding parameters and/or may be specified in a Welding Process Specification (WPS) or similar file. Based on the transformation data stored in the control circuitry (e.g., in memory 84), the control circuitry 32, 56 generates a second welding profile based on the same welding parameters (e.g., material thickness, wire diameter, wire type, gas type, and/or any other factors). The control circuitry 32, 56 compensates for the added preheat power by generating a second welding regime by including non-zero preheat power (e.g., preheat temperature, preheat voltage, target wire resistance, etc.) and adjusting welding parameters (e.g., welding voltage, wire feed speed, inductance, pulse parameters, AC parameters, etc.) of the first welding regime.

As an example generation of the second welding profile, the first example welding profile programmed by the operator may specify a welding voltage of 22 volts and a welding current of 245 amps without preheating (e.g., preheat off). Based on the stored transformation data, the example control circuitry 32, 56 may generate a second welding protocol using a welding voltage of 18 volts and a welding current of 266 amps, where the preheat voltage is 4 volts and the preheat current is 150 amps. The operator may then switch between the first and second welding protocols while welding and/or not welding, and/or may quickly recall the first and/or second welding protocols.

The example control circuitry 32, 56 may select the preheating parameters of the second welding regime to improve deposition, reduce hydrogen in the welding wire and/or the final weldment, and/or achieve other benefits of wire preheating relative to the first welding regime. The control circuitry 32, 56 may generate and store multiple accompanying welding scenarios to achieve different effects (e.g., hydrogen reduction, increase in welding, etc.) and/or different degrees of preheating effects (e.g., higher welding, highest welding, etc.).

In an example of operation involving a welding profile, a welding operator may select a first welding profile via power selector circuitry 52 on the welding torch 14, on the operator interface 34, and/or on the user interface 66. For example, the operator may pick up the welding torch 14 and tap the trigger one or more times to operate the power selector circuitry 52. An example first welding protocol specifies a first welding power and a first preheat power. In response to the selection of the welding profile, the control circuitry 32 (or the control circuitry 56) controls the power conversion circuitry 30 (or the power conversion circuitry 58), as well as any other welding accessories (e.g., the wire feeder, the wire feed assembly 60, etc.), according to parameters specified in the first welding profile during the welding operation.

Later, the operator selects the second welding regime via power selector circuitry 52 on the welding torch 14, on the operator interface 34, and/or on the user interface 66. For example, the operator may tap the trigger one or more times to operate the power selector circuitry 52 to select the second welding regime. As the operator switches the welding profile, the operator interface 34, the user interface 66, and/or an interface (e.g., one or more indicators, a display screen, etc.) on the welding torch 14 may display an indication of the selected welding profile and/or one or more parameters associated with the selected welding profile (e.g., welding/preheating balance, workpiece thickness, welding voltage and wire feed speed, preheating power, etc.).

While the examples of fig. 1 and 2 include power conversion circuitry that outputs both welding power and preheating power, other examples may involve multiple separate welding-type power sources that separately provide welding-type power and preheating power. Examples of such Systems are disclosed in U.S. patent application Ser. No. 15/343,992 entitled "System, method, and Apparatus for preheating Welding Wire" filed on day 11/2016 and method to Preheat Welding Wire "and U.S. patent application Ser. No. 16/005,139 entitled" System, method, and Apparatus for preheating Welding Wire for Low Hydrogen Welding "filed on day 11/2018. U.S. patent application serial No. 15/343,992 and U.S. patent application serial No. 16/005,139 are incorporated herein by reference in their entirety. In such an example, the power selector circuitry 52 may control multiple welding-type power sources that separately provide welding power and pre-heating power, and/or the control circuitry 32, 56 may control communication between the multiple power sources to control welding parameters and/or pre-heating parameters at the multiple power sources.

FIG. 3 illustrates another example power supply 300 configured to provide welding-type output power and pre-heating power to the welding torch 14 and to control the welding-type power and the pre-heating power based on input signals. The example welding system 300 includes power conversion circuitry 302, control circuitry 32, an operator interface 34, a gas control valve 46, and a wire feed assembly 60.

Instead of providing welding-type power directly to the preheating wire feeder 16 via two conductors as in the example system 10 of fig. 1, the example power supply 300 includes power conversion circuitry 302 that is coupled to the welding torch 14 via output conductors 304, 306 and to the workpiece 44 via a work cable 308 to enable completion of the circuit. The example power conversion circuitry 302 of FIG. 3 receives input power from the primary power supply 22 and outputs welding-type power and pre-heating power to the welding torch 14 via the conductors 304, 306 and/or the work cable 308.

Fig. 4a is a block diagram of example power conversion circuitry 400 that may be used to implement the power conversion circuitry 58 of fig. 2 for converting input welding-type power to output welding-type power and preheat power. The example power conversion circuitry 400 of fig. 4a includes preheat power conversion circuitry 402 and welding power conversion circuitry 404. Both the preheat power conversion circuitry 402 and the welding power conversion circuitry 404 are coupled to the input to receive respective portions of the input power 406 (e.g., from the primary power source 22 or from the power source 12 via the terminals 40 of fig. 2).

Each of the example preheat power conversion circuitry 402 and welding power conversion circuitry 404 includes respective conversion circuitry. In the example of fig. 4a, preheat power conversion circuitry 402 includes a boost conversion circuit 408a, a bus capacitor 410a, and a buck conversion circuit 412 a. Similarly, the welding power conversion circuitry 404 includes a boost converter circuit 408b, a bus capacitor 410b, and a buck converter circuit 412 b. The boost converter circuits 408a, 408b are each configured to convert the input power 406 into a respective bus voltage that is output to a respective buck converter 412a, 412 b. The example buck converters 412a, 412b convert the bus voltage to a desired output. For example, buck converter 412a converts the bus voltage output by boost converter 408a to preheat output 414 having a preheat output voltage and/or a preheat output current. Similarly, the buck converter 412b converts the bus voltage output by the boost converter 408b to a welding output 416 having a welding output voltage and/or a welding output current. The bus capacitors 410a, 410b store energy to reduce bus voltage ripple due to variations in the power output by the buck converters 412a, 412 b.

The example control circuitry 32, 56 of fig. 1, 2, and/or 3 controls the boost converters 408a, 408b and the buck converters 412a, 412b based on the input welding-type current and the desired preheat output and the desired weld output. The control circuitry 32, 56 may control one or both of the preheat power conversion circuitry 402 and the weld power conversion circuitry 404 to be off at a given time. For example, the control circuitry 56 may control the welding power conversion circuitry 404 to output a welding-type current for a first welding operation or a first portion of a welding operation, and then control both the preheat power conversion circuitry 402 and the welding power conversion circuitry 404 to perform a second welding operation or a second portion of the welding operation using both the welding power and the preheat power.

In some examples, the control circuitry 32, 56 is configured to adjust control of the welding power conversion circuitry to adjust the welding output 416 based on the pre-heat output to maintain consistent heat input to the weld and/or increase deposition. For example, the control circuitry 32, 56 may decrease the welding output 416 (e.g., welding voltage and/or welding current) via the welding power conversion circuitry 404 based on controlling the preheat power conversion circuitry 402 to increase the preheat output 414.

Fig. 4b is a block diagram of example power conversion circuitry 420 that may be used to implement the power conversion circuitry 58, 302 of fig. 2 and/or 3 to convert input welding-type power to output a welding output 416 and a preheat output 414. The example power conversion circuitry 420 of fig. 4b includes preheat power conversion circuitry 422 and welding power conversion circuitry 424. In contrast to the example power conversion circuitry 400 of fig. 4a, the preheat power conversion circuitry 422 and the welding power conversion circuitry 424 receive bus voltage from the shared boost converter 408, rather than the input power 406 as an input.

Both the preheat power conversion circuitry 422 and the welding power conversion circuitry 424 are coupled to the bus voltage output by the boost converter 408, which converts the input power 406 to the bus voltage. In the example of fig. 4b, bus capacitor(s) 410 are also shared between the preheat power conversion circuitry 422 and the welding power conversion circuitry 424, although the preheat power conversion circuitry 422 and the welding power conversion circuitry 424 may each have a corresponding bus capacitor 410. The example buck converters 412a, 412b convert the bus voltage to a desired output. The example control circuitry 32, 56 of fig. 1, 2, or 3 controls the boost converter 408 and the buck converters 412a, 412b to output a preheat output 414 and/or a weld output 416.

Although the examples of fig. 1, 2, 4a, and 4b were disclosed above with reference to a pre-heated wire feeder, other types of welding accessories may also be used. For example, the welding teach pendant may be configured to include the power conversion circuitry disclosed herein to provide welding power and preheat power based on input welding-type power and used in conjunction with a conventional wire feeder to provide welding power and preheat power to a welding torch.

Additionally, while the foregoing examples are described with reference to resistively preheating the wire at the torch, the disclosed examples may also be used in conjunction with other forms of wire heating, such as induction heating of the wire, hot wire techniques, arc-based preheating (where heat is applied to the wire using an arc prior to a welding arc), laser-based preheating, and/or any other form of wire heating. For example, the preheating circuit (e.g., contact tips 18, 20) may be replaced with any other type of preheater, such as resistive preheating (e.g., via two or more contact points on the welding wire 54), inductive heating of the welding wire 54 (e.g., via routing the welding wire 54 through or near an induction coil), arc-based preheating (e.g., via one or more tungsten electrodes configured to establish an arc to the welding wire 54), laser-based preheating (e.g., via a laser configured to output energy to the welding wire 54), radiant heating (e.g., via a heating coil that is not in contact with the welding wire 54 but is configured to heat the welding wire 54 by radiation), convective heating (e.g., via a heating coil, ceramic, or other heating material configured to contact the welding wire 54 to transfer heat to the welding wire 54), other configurations of resistive preheating (e.g., via a heating coil, ceramic, or other heating, And/or any other pre-heating technique.

FIG. 5 is a flow diagram representing example machine readable instructions 500 that may be executed by the control circuitry of the example pre-heat wire feeder 16 of FIG. 1 or another accessory to convert welding-type power to welding-type power and pre-heat power. The example instructions 500 are described below with reference to the preheating wire feeder 16 of fig. 2 and the example power conversion circuitry 400 of fig. 4 a. However, other implementations of preheating the wire feeder 16, power conversion circuitry 58, and/or other welding accessories may be used to execute the instructions 500.

At block 502, the control circuitry 56 determines whether an input specifying a welding regime has been received. For example, control circuitry 56 may receive communications from input devices, such as power selector circuitry 52, user interface 66, and/or operator interface 34. The input may specify a particular welding profile of the one or more stored welding profiles, and/or include a relative input indicating a welding profile relative to a current welding profile or set of parameters (e.g., a "next" profile selection, a "previous" profile selection, a left/right selector, an up/down selector, etc.).

If an input specifying a welding regime has been received (block 502), at block 504, the control circuitry 56 determines a welding power output and/or a preheating power output based on the specified welding regime. For example, the control circuitry 56 may look up the selected welding profile in the memory 84 and implement welding and/or preheating parameters, such as welding voltage, wire feed speed, and/or preheating voltage.

After determining the welding power output and/or the preheat power output (block 504), or if an input specifying a welding regime has not been received (block 502), the control circuitry 56 determines whether the weld is valid at block 506. For example, the control circuitry 56 may determine whether a trigger signal has been received from a handheld torch or whether a power output command has been received from a robotic welding system. If the weld is not valid (block 506), control returns to block 502.

If the weld is valid (block 506), at block 508, the control circuitry 56 determines whether to allow the weld output. For example, the control circuitry 56 may determine whether the welding power output determined in block 504 is greater than a threshold arc output. If the welding output is allowed (block 508), at block 510, the control circuitry 56 controls the power conversion circuitry 58 (e.g., the welding power conversion circuitry 404 of fig. 4 a) to convert the input power to the welding output 416 based on the determined welding output power. At block 512, the power conversion circuitry 58 (e.g., the welding power conversion circuitry 404) outputs welding-type power to the welding torch 14 (e.g., via the first contact tip 18 and the workpiece 44).

After outputting welding-type power to the welding torch (block 512), or if welding output is not allowed based on the welding regime (block 510), the control circuitry 56 determines whether to allow preheating output at block 514. For example, the control circuitry 56 may determine whether the pre-heat power output determined in block 504 is greater than a threshold value, whether the wire feed speed is greater than a threshold speed, and/or whether the wire temperature and/or the wire resistance exceed respective threshold values. For example, while the selected welding regime may indicate a particular pre-heating power, temperature, or resistance, the example control circuitry 56 may reduce the pre-heating power and/or stop the pre-heating when the wire temperature and/or wire resistance is greater than a threshold and/or if the wire is fed at a speed less than a threshold speed.

If preheating is allowed (block 514), at block 516, control circuitry 56 controls power conversion circuitry 58 (e.g., preheating power conversion circuitry 402 of fig. 4 a) to convert input power to preheating output 414 based on the determined preheating power. At block 518, the power conversion circuitry 58 (e.g., preheat power conversion circuitry 402) outputs preheat power. For example, the power conversion circuitry 58 may output welding power to the welding torch 14 (e.g., via the first contact tip 18 and the second contact tip 20 to facilitate resistive preheating). Additionally or alternatively, the power conversion circuitry 58 may output pre-heating power to pre-heating devices within the wire feed assembly 60 or to pre-heating devices integral with the weld cable between the wire feeder 16 and the welding torch 14.

After outputting preheat power (block 518), or if preheat is not allowed (block 514), control returns to block 506 to determine whether the weld is still active.

While blocks 508-512 and blocks 514-518 are illustrated as sequential, blocks 508-512 may be performed in parallel with blocks 514-518 to control the power conversion circuitry 58 to output welding-type power and preheat power while welding is active.

Fig. 6 is a flow diagram representative of example machine readable instructions 600 that may be executed by the example welding system of fig. 1 or 2 and/or the example welding-type power supply 300 of fig. 3 to cooperatively control welding-type power and pre-heating power based on an input signal. The example instructions 600 are described below with reference to the preheating wire feeder 16 of fig. 2 and the example power conversion circuitry 400 of fig. 4 a. However, the instructions 600 may be executed using other implementations of the power source 12, the preheat wire feeder 16, the power conversion circuitry 58, and/or other welding power sources and/or welding accessories.

At block 602, the control circuitry 56 determines whether a welding operation is being performed. For example, the control circuitry 56 may determine whether a trigger signal has been received from a handheld torch or whether a power output command has been received from a robotic welding system. If a welding operation is not being performed (block 602), control repeats at block 602 to wait for the welding operation.

If a welding operation is not being performed (block 602), at block 604, the control circuitry 56 determines a value of the control signal (e.g., from the power selector circuitry 52). For example, control circuitry 56 may receive a communication or signal from an input device (such as power selector circuitry 52, user interface 66, and/or operator interface 34) having a value within a predetermined range. Inputs (e.g., analog signals or encoded digital signals) may be received from a trigger, a wheel, a dial, a knob, a foot pedal, and/or any other input device that generates a signal (e.g., via an encoder, potentiometer, etc.).

At block 606, the control circuitry 56 determines a coordinated welding power output, a coordinated preheating power output, and/or a coordinated wire feed speed based on the specified welding schedule, based on the value of the control signal. For example, the control circuitry 56 may look up the value of the control signal in the memory 84 and implement welding and/or preheating parameters, such as welding voltage, wire feed speed, and/or preheating voltage, based on the value and a coordinated control scheme represented by a range of values. For example, the coordinated control scheme may represent a balance between welding power and preheating power (e.g., a balance between penetration depth and deposition), represent heat input into the weld (e.g., increase and decrease heat input by primarily increasing and decreasing welding output and wire feed speed while compensating by preheating), represent welding speed (e.g., increase and decrease deposition by primarily increasing and decreasing preheating and wire feed speed while compensating by welding output), and/or represent any other parameter and/or variable. In some examples, the operator may select a coordinated control scheme.

At block 608, the control circuitry 56 controls the wire feed assembly 60 based on the determined wire feed speed. At block 610, the control circuitry 56 determines whether to allow the welding output. For example, the control circuitry 56 may determine whether the welding power output determined in block 606 is greater than a threshold arc output. If the welding output is allowed (block 610), at block 612, the control circuitry 56 controls the power conversion circuitry 58 (e.g., the welding power conversion circuitry 404 of fig. 4 a) to convert the input power to the welding output 416 based on the determined welding output power. At block 614, the power conversion circuitry 58 (e.g., the welding power conversion circuitry 404) outputs welding-type power to the welding torch 14 (e.g., via the first contact tip 18 and the workpiece 44).

After outputting welding-type power to the welding torch (block 614), or if the welding output is not allowed based on the value of the control signal (block 610), the control circuitry 56 determines whether to allow the preheat output at block 616. For example, the control circuitry 56 may determine whether the pre-heat power output determined in block 606 is greater than a threshold value, whether the wire feed speed is greater than a threshold speed, and/or whether the wire temperature and/or the wire resistance exceed respective threshold values. For example, while the selected welding regime may indicate a particular pre-heating power, temperature, or resistance, the example control circuitry 56 may reduce the pre-heating power and/or stop the pre-heating when the wire temperature and/or wire resistance is greater than a threshold and/or if the wire is fed at a speed below a threshold speed.

If preheating is allowed (block 616), at block 618, the control circuitry 56 controls the power conversion circuitry 58 (e.g., preheating power conversion circuitry 402 of fig. 4 a) to convert the input power to preheating output 414 based on the determined preheating power. At block 620, the power conversion circuitry 58 (e.g., preheat power conversion circuitry 402) outputs preheat power. For example, the power conversion circuitry 58 may output welding power to the welding torch 14 (e.g., via the first contact tip 18 and the second contact tip 20 to facilitate resistive preheating). Additionally or alternatively, the power conversion circuitry 58 may output pre-heating power to pre-heating devices within the wire feed assembly 60 or to pre-heating devices integral with the weld cable between the wire feeder 16 and the welding torch 14.

After outputting the pre-heating power (block 620), or if pre-heating is not allowed (block 616), control returns to block 602 to determine whether the welding operation is still being performed.

While blocks 610-614 and 616-620 are illustrated as sequential, blocks 610-614 may be performed in parallel with blocks 616-620 to control the power conversion circuitry 58 to output welding-type power and preheat power while welding is active.

The present apparatus and/or method may be implemented in hardware, software, or a combination of hardware and software. The method and/or system may be implemented in a centralized fashion in at least one computing system, processor, and/or other logic circuit, or in a distributed fashion where different elements are spread across several interconnected computing systems, processors, and/or other logic circuits. Any kind of computing system or other apparatus adapted for carrying out the methods described herein is suited. A typical combination of hardware and software may be a processing system integrated in a welding power supply with program or other code that, when loaded and executed, controls the welding power supply such that it carries out the methods described herein. Another exemplary implementation may include an application specific integrated circuit or chip, such as a Field Programmable Gate Array (FPGA), a Programmable Logic Device (PLD), or a Complex Programmable Logic Device (CPLD), and/or a system on a chip (SoC). Some implementations may include a non-transitory machine-readable (e.g., computer-readable) medium (e.g., flash memory, optical disks, magnetic storage disks, etc.) having one or more lines of code stored thereon that are executable by a machine to thereby cause the machine to perform the processes described herein. As used herein, the term "non-transitory computer readable medium" is defined to include all types of machine readable storage media and to exclude propagating signals.

Example control circuit implementations may be a microcontroller, field programmable logic circuitry, and/or any other control or logic circuitry capable of executing instructions to execute welding control software. The control circuit may also be implemented in analog circuitry and/or a combination of digital and analog circuitry.

While the present method and/or system has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the method and/or system. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the scope thereof. For example, the blocks and/or components of the disclosed examples may be combined, divided, rearranged, and/or otherwise altered. Thus, the present methods and/or systems are not limited to the particular implementations disclosed. Instead, the present method and/or system will include all implementations that fall within the scope of the following claims, both literally and under the doctrine of equivalents.

Claims (21)

1. A welding system, comprising:

power conversion circuitry configured to:

Outputting welding type power to a welding circuit; and

outputting preheating power to a preheater; and

control circuitry configured to:

receiving input selecting one of a plurality of welding protocols, each of the plurality of welding protocols specifying some combination of welding-type output power and pre-heat output power; and

controlling the power conversion circuitry to output the welding-type power and the pre-heating power based on the selected one of the plurality of welding protocols.

2. The welding system of claim 1, wherein the power conversion circuitry comprises:

welding power conversion circuitry configured to output the welding-type power; and

preheat power conversion circuitry configured to output the preheat power.

3. The welding system of claim 2, wherein the welding power conversion circuitry is configured to convert a first portion of welding-type power received at the power conversion circuitry to the welding-type power, and the preheat power conversion circuitry is configured to convert a second portion of the welding-type power received at the power conversion circuitry to the preheat power.

4. The welding system of claim 2, wherein the welding power conversion circuitry is configured to convert a first portion of the AC input power received at the power conversion circuitry to the welding-type power, and the preheat power conversion circuitry is configured to convert a second portion of the AC input power received at the power conversion circuitry to the preheat power.

5. The welding system of claim 1, wherein the control circuitry is configured to receive the input from an operator input device.

6. The welding system of claim 5, wherein the input is indicative of a state of the operator input device, wherein the control circuitry is configured to:

selecting a first welding profile of the plurality of welding profiles specifying a non-zero preheat current while the input indicates the operator input device is pressed or activated by an operator; and

selecting a second welding profile of the plurality of welding profiles when the input indicates that the operator input device is not pressed or deactivated.

7. The welding system of claim 6, wherein the second welding regime of the plurality of welding regimes specifies a preheat current of substantially zero.

8. The welding system of claim 1, wherein the control circuitry is configured to define a first welding protocol of the plurality of welding protocols based on a second welding protocol of the plurality of welding protocols.

9. The welding system of claim 8, wherein the first welding regime of the plurality of welding regimes comprises a first welding output power and a first pre-heat output power, and the second welding regime of the plurality of welding regimes comprises a second welding output power and a second pre-heat output power.

10. The welding system of claim 9, wherein the first one of the plurality of welding protocols comprises a first wire feed speed and the second one of the plurality of welding protocols comprises a second wire feed speed.

11. The welding system of claim 10, wherein the first welding output power is greater than the second welding output power, the second pre-heated output power is greater than the first pre-heated output power, and the second wire feed speed is greater than the first wire feed speed.

12. The welding system of claim 9, wherein the second pre-heating power output is substantially zero and the first pre-heating power output is greater than zero.

13. The welding system of claim 1, wherein the control circuitry is configured to receive the input from a welding control system via a communication network.

14. A welding system, comprising:

power conversion circuitry configured to:

outputting welding type power to a welding circuit; and

outputting preheating power to a preheater; and

control circuitry configured to cooperatively control the welding-type power and the pre-heating power during a welding operation based on a control signal.

15. The welding system of claim 14, further comprising communication circuitry configured to receive the control signal.

16. The welding system of claim 15, wherein the communication circuitry is configured to receive the control signal from at least one of the welding-type welding torch or a foot pedal.

17. The welding system of claim 14, wherein the control circuitry is configured to cooperatively control a wire feed speed with the welding-type power and the pre-heating power.

18. The welding system of claim 14, wherein the control circuitry is configured to cooperatively control the pre-heat power within a power range between zero and an upper pre-heat power limit.

19. The welding system of claim 14, wherein the control circuitry is configured to cooperatively control a total heat input to the weld based on the control signals received from a control device during the welding operation.

20. The welding system of claim 19, wherein the control circuitry is configured to maintain a substantially constant total heat input by controlling at least one of the power conversion circuitry to output the pre-heating power and the welding-type power based on the control signal.

21. The welding system of claim 19, wherein the control signal is indicative of an amount a trigger of the welding torch is depressed, an amount a foot pedal is depressed, or an output of a knob input or a dial input.

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