System and method for monitoring the life of a welding torch

Abstract

A system and method for monitoring the life of a welding torch. An example wire feeder includes a frame, a housing configured to deliver a welding-type current to a welding torch via a torch connector and positioned to receive a wire electrode, one or more drive rollers configured to drive the wire electrode to the welding torch, the one or more drive rollers being electrically insulated from the frame, and wherein the wire electrode is electrically insulated from the frame, and a sensor configured to determine at least one of a voltage or an impedance between a first point electrically coupled to the wire electrode and a reference point.

Description

[0001] Related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. 62 / 856,476, entitled “SYSTEMS AND METHODS TO MONITOR THE LIFE OF A WELDING TORCH,” filed on June 3, 2019. The entire contents of U.S. Provisional Patent Application Serial No. 62 / 856,476 are expressly incorporated herein by reference. Technical Field

[0003] The present disclosure relates to welding systems and apparatus, and more particularly to systems and methods for monitoring the life of a welding torch. Background Art

[0004] Welding is an increasingly common process across all industries. A wide variety of welding systems and welding control schemes have been implemented for various applications. In a continuous welding operation, gas metal arc welding ("GMAW") technology allows for the formation of a continuous weld bead by feeding a wire shielded by an inert gas from a welding torch. Electrical power is applied to the wire at the welding torch and an electrical circuit is completed through the workpiece to maintain a welding arc that melts the electrode wire and the workpiece to form the desired weld. Due to the voltage drop across the welding circuit conductors, the voltage across the welding arc is less than the voltage output by the welding-type power source. The welding torch degrades over time, which can lead to undesirable effects. Summary of the Invention

[0005] The present disclosure relates to welding systems and methods, and more particularly to systems and methods for determining the impedance of a welding torch or the voltage drop across the welding torch to monitor degradation of the welding torch, substantially as illustrated by and described in conjunction with at least one figure, and more fully set forth in the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is an illustration of an example welding-type system according to aspects of the present disclosure.

[0007] Figure 2 is an illustration of an example torch wire bushing and torch connector.

[0008] Figure 3 is an illustration of an example wire feeder wire guide having an inlet.

[0009] Figure 4 is an illustration of a view of the front end of an example welding torch.

[0010] Figure 5 is a flow chart representing example machine readable instructions that may be executed by a welding-type system to determine the impedance of a welding torch.

[0011] Figure 6 is a flow chart representative of example machine-readable instructions that may be executed by a welding-type system to determine whether a welding torch has failed or requires maintenance based on a determined torch impedance.

[0012] Figure 7 is a flow chart representative of example machine-readable instructions that may be executed by a welding-type system to determine a remaining usable time of a welding torch based on a determined torch impedance.

[0013] Figure 8 is a flow chart representative of example machine readable instructions that may be executed by a welding-type system to determine a failure mechanism of a welding torch based on a determined torch impedance.

[0014] The accompanying drawings are not necessarily drawn to scale. Where appropriate, similar or identical reference numbers are used to refer to similar or identical parts. DETAILED DESCRIPTION

[0015] Predictive maintenance or failure prediction is desirable in various welding applications, including automated welding applications. Particularly in automated welding applications, high operating costs, production losses, lack of preventative maintenance, and timely production requirements have led to an increased desire to avoid unplanned downtime. Currently, there is no accurate or convenient way to predict failure of a GMAW, metal inert gas ("MIG"), or metal active gas ("MAG") welding torch before a catastrophic failure occurs. Catastrophic failure of a welding torch can result in a variety of undesirable consequences, including damage to the welding equipment, damage to the control system, and poor welds. MIG welding torches can have several failure mechanisms, including shielding gas leaks, stuck electrode wire feed, insulation damage due to thermal or mechanical overload, conductor degradation (e.g., broken copper wire within a flexible cable), and loose component connections. The disclosed example system monitors conductor degradation of a welding torch by tracking impedance and / or voltage drop across the conductor in order to determine and predict degradation and / or life of the welding torch.

[0016] In the disclosed example system, the electrode wire is electrically isolated from the welding circuit except at the front end of the welding torch. For example, the electrode wire can be electrically isolated from the wire feeder frame (e.g., the rack or connector between the power cable and the welding torch) and the welding circuit, so that the length of the electrode wire is between the source of the electrode wire (e.g., a wire drum, wire reel, etc.) and the contact tip on the welding torch. Therefore, the electrode wire carries the same voltage as the contact tip even within the wire feeder. The voltage at the front end of the welding torch is measured by measuring the voltage at the electrode wire. This voltage at the electrode wire can be compared with the voltage at the wire feeder to determine the voltage drop across the welding torch, thereby determining the impedance of the welding torch. The impedance of the welding torch can be monitored over time, and the impedance change trend(s) and / or change characteristics(s) can be used to predict degradation or failure of the welding torch. For example, the control circuit system can determine the root cause of the failure based on the shape of the trend. When the welding torch is about to fail, a signal can be output to warn or alert the operator or maintenance technician, and the signal can indicate the type of failure.

[0017] As used herein, the term "welding-type power supply" and / or "welding-type power supply" refers to any device capable of supplying power to welding, cladding, plasma cutting, induction heating, laser (including laser welding, laser composite and laser cladding), carbon arc cutting or carbon arc gouging, and / or resistive preheating when power is applied, including but not limited to transformer-rectifiers, inverters, converters, resonant power supplies, quasi-resonant power supplies, switch-mode power supplies, etc., as well as control circuit systems and other auxiliary circuit systems associated therewith.

[0018] The term "welding-type system" as used herein includes any device capable of supplying power suitable for welding, plasma cutting, induction heating, CAC-A and / or hot wire welding / preheating (including laser welding and laser cladding), including inverters, converters, choppers, resonant power supplies, quasi-resonant power supplies, etc., as well as control circuit systems and other auxiliary circuit systems associated therewith.

[0019] As used herein, the term "welding-type operation" includes actual welding of two or more physical objects (e.g., resulting in a join, such as welding or brazing), covering, texturing and / or heat treating, and / or cutting of physical objects, as well as simulated or virtual welding (e.g., visualization of welding without physical welding occurring).

[0020] For convenience, the term "power" is used throughout this specification, but it also includes related measurements such as energy, current, voltage, and enthalpy. For example, controlling "power" may involve controlling voltage, current, energy, and / or enthalpy, and / or controlling based on "power" may involve controlling based on voltage, current, energy, and / or enthalpy. Such power measured in watts as the product of voltage and current (e.g., V*I power) is referred to herein as "wattage."

[0021] As used herein, the terms "control circuitry" and "control circuitry" may include digital and / or analog circuitry, discrete and / or integrated circuitry, microprocessors, digital signal processors (DSPs), and / or other logic circuitry, and / or associated software, hardware, and / or firmware. The control circuitry may include a memory and a processor for executing instructions stored in the memory. The control circuitry or control circuitry may be located on one or more circuit boards that form part or all of a controller and are used to control the welding process, equipment such as a power source or wire feeder, motion, automation, monitoring, air filtration, displays, and / or any other type of welding-related system.

[0022] As used herein, the terms "circuit" and "circuitry" refer to physical electronic components, any analog and / or digital components, power elements and / or control elements, such as a microprocessor or digital signal processor (DSP) or the like, including discrete components and / or integrated components, or parts and / or combinations thereof (i.e., hardware), and any software and / or firmware ("code") that may configure, be executed by, and / or otherwise be associated with the hardware. As used herein, for example, a particular processor and memory may comprise a first "circuit" when executing a first line or more lines of code, and may comprise a second "circuit" when executing a second line or more lines of code.

[0023] As used herein, a circuit system is “operable” to perform a function whenever it includes the necessary hardware and code (if necessary) to perform that function, regardless of whether performance of that function is disabled or not enabled (e.g., by a user-configurable setting, factory adjustment, etc.).

[0024] As used herein, the terms "memory" and / or "memory device" refer to computer hardware or circuitry for storing information for use by a processor and / or other digital device. The memory and / or memory device may be any suitable type of computer memory or any other type of electronic storage medium, such as read-only memory (ROM), random-access memory (RAM), cache memory, compact disk read-only memory (CDROM), electro-optical memory, magneto-optical memory, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state storage devices, computer-readable media, or the like.

[0025] As used herein, the terms "torch," "welding torch," or "welding tool" refer to a device configured to be manipulated to perform welding-related tasks and may include a handheld welding torch, a robotic welding torch, a welding gun, or other device for generating a welding arc.

[0026] As used herein, “and / or” refers to any one or more of the items connected by “and / or” in a list. 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” refers to “one or both of x and y”. As another example, “x, y and / or z” refers to any element in the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. In other words, “x, y and / or z” refers to “one or more of x, y and z”. As used herein, the term “exemplary” refers to serving as a non-limiting example, instance, or example. As used herein, the terms “such as” and “for example” elicit a list of one or more non-limiting examples, instances, or examples.

[0027] The disclosed example wire feeder includes: a frame; a housing configured to transmit a welding type current to a welding torch via a welding torch connector and positioning the welding torch connector to accommodate an electrode wire; one or more drive rollers configured to drive the electrode wire to the welding torch, the one or more drive rollers being electrically insulated from the frame, wherein the electrode wire is electrically insulated from the frame; and a sensor configured to determine at least one of a voltage or an impedance between a first point electrically coupled to the electrode wire and a reference point.

[0028] In some example wire feeders, the reference point is electrically coupled to the frame. In some example wire feeders, the first point is electrically equivalent to a contact tip of the welding torch. In some example wire feeders, the first point is electrically equivalent to a fixed head of the welding torch.

[0029] Some example wire feeders include processing circuitry configured to determine at least one state of the welding torch based on the voltage or the impedance. Some example wire feeders include processing circuitry configured to determine impedance based on a result of dividing the voltage by the measured welding-type current.

[0030] Some example wire feeders include a processing circuit system configured to compare the impedance with a threshold impedance and output a signal when the torch impedance meets the threshold impedance. In some examples, the signal provides an alarm to an operator. In some example wire feeders, the signal includes a command to cut off the welding power supplied to the welding torch, cut off the welding power supplied to the wire feeder, or turn off the wire feeder. Some example wire feeders include a processing circuit system configured to monitor changes in the impedance and predict the type of torch failure based on the changes.

[0031] In some example wire feeders, the type of torch fault is one of a conductor break in the torch cable, a loose connection between components, improper component installation, a deteriorated rotational connection, or insulation damage. Some example wire feeders include processing circuitry configured to monitor a rate of increase in impedance and predict the type of torch fault based on the rate. Some example wire feeders include processing circuitry configured to monitor a change in impedance and predict a time to failure based on the change.

[0032] Some example wire feeders include: a wire guide configured to receive the electrode wire and guide the electrode wire to the one or more drive rollers, wherein the wire guide includes: a conductive layer configured to guide the electrode wire; and an insulating layer configured to electrically insulate the electrode wire and the conductive layer from the frame. In some example wire feeders, the wire guide includes a single-coil spring. In some example wire feeders, the wire guide includes an outer metal tube layer.

[0033] The disclosed example welding system includes: a welding torch, the welding torch including a contact tip configured to conduct a welding-type current to an electrode wire; a wire feeder, the wire feeder configured to feed the electrode wire from an electrode wire source to the welding torch; a conductive path, the conductive path for delivering welding power from a welding-type power supply to the contact tip; an electrically insulating path, the electrically insulating path for delivering the electrode wire from the electrode wire source to the contact tip; and a sensor, the sensor configured to determine at least one of a voltage or an impedance between a first point coupled to the electrode wire and a reference point.

[0034] Some example welding systems further include a processing circuit system configured to determine at least one state of the welding torch based on the voltage or the impedance. Some example welding systems further include a processing circuit system configured to compare the impedance with a threshold impedance and output a signal when the welding torch impedance meets the threshold impedance. Some example welding systems further include a processing circuit system configured to monitor changes in the impedance and predict a type of welding torch failure based on the changes. In some example welding systems, the reference point includes a frame of the wire feeder or a front end of a cable of the welding torch.

[0035] Figure 1 An exemplary GMAW system 100 is shown that includes a welding-type power supply 102, a wire feeder 104, a gas cylinder 106, and a welding torch 108. The welding-type power supply 102 includes power conversion circuitry configured to condition input power (e.g., from an AC grid, an engine / generator set, a combination thereof, or other alternative power source) to welding-type power.

[0036] The example wire feeder 104 includes a wire feeder frame 110 that is electrically connected to a welding power source 102 via one or more cables 112, which may include power and / or control conductors and / or cables. The cables 112 are connected to output terminals 114 of the welding power source. The wire feeder 104 feeds a welding electrode wire 116 from a wire source 118 (e.g., a wire spool, a wire drum, etc.) to a welding torch 108 via one or more drive rollers 120.

[0037] exist Figure 1In the example of FIG, the electrode wire 116 is delivered from a wire source 118 to the wire feeder 104 via an insulated conduit 117. Although in the illustrated example system 100, the electrode wire source 118 is shown as being external to the wire feeder 104, in some examples, the electrode wire source 118 (e.g., a wire spool) is integrated into the wire feeder 104 (e.g., within its housing). Further, although the wire feeder 104 is shown as being external to the welding power source 102, in some examples, the wire feeder 104 can be integrated into the housing of the welding power source 102.

[0038] During welding operations, the welding power supply 102 outputs welding current from terminals 114 to the wire feeder 104 via the cable 112. In other examples, the wire feeder 104 is integrated into the power supply 102, in which case the cable 112 may be internal to the power supply and / or connectable to the terminals 114. Figure 1 An example wire feeder 104 may include circuitry (e.g., conductors, contactors, power conversion circuitry, etc.) configured to deliver a welding-type current to a welding torch 108 that is connected to the wire feeder 104.

[0039] Through the wire feeder 104, the welding power source is electrically connected to a wire feeder housing 122 configured to receive a torch connector 124. The torch connector 124 includes power pins for receiving a welding current and a wire bushing cap for receiving and guiding the electrode wire 116 into an insulating wire bushing. The welding current flows to the housing 122 and the torch connector 124. The torch connector 124 conducts the welding current to the welding torch 108 via a conductor 127 included in a torch cable 128. The cable 128 also delivers shielding gas and the electrode wire 116 from the wire feeder 104 to the welding torch 108.

[0040] The welding torch 108 conducts welding-type current from a conductor 127 (e.g., via one or more conductors and / or components within the welding torch 108) to a contact tip 126 for delivery to the wire electrode 116. The welding-type current flows from the contact tip 126 to the wire electrode 116 and creates an arc from an end 132 of the wire electrode 116 to a workpiece 134. During a welding operation, a significant voltage drop occurs across the arc 136 between the wire electrode end 132 and the workpiece 134. A ground cable 138 (e.g., via a clamp, bolt, or plug) connects the workpiece 134 to a second power terminal 139 of the welding-type power source 102 to complete the welding circuit between the welding-type power source 102, the wire feeder 104, the welding torch 108, and the workpiece 134.

[0041] In the example system 100, the wire electrode 116 is electrically isolated from the welding-type current except at the contact tip 126 (and / or any other location within the welding torch 108). The wire electrode 116 is insulated from the conductor 127 of the cable 128 and the torch body 108 via an insulating wire bushing 140 that delivers the wire electrode 116 from the torch connector 124. In some examples, the wire electrode 116 can be in electrical contact with the insulating wire bushing 140 while the wire bushing 140 is electrically isolated from the conductor 127.

[0042] Within the wire feeder 104, the wire electrode 116 is insulated from the wire feeder frame 110 and from any circuitry conducting welding-type current. For example, the one or more drive rollers 120 are electrically insulated from at least one of the wire electrode 116 or the wire feeder frame 110. For example, the drive rollers 120 can be insulated from the frame 110 such that the one or more drive rollers 120 are electrically insulated from the wire feeder frame 110 even when the wire electrode 116 is not installed.

[0043] In some examples, if the wire feeder 104 includes two sets of drive rollers 120, the wire feeder 104 further includes an intermediate guide 121 between the two sets of drive rollers 120. The intermediate guide 121 guides and supports the wire electrode 116 between the two sets of drive rollers 120 and insulates the wire electrode 116 from the wire feeder frame 110. The insulating wire bushing 140 may include an insulator to electrically insulate the wire electrode 116 from the housing 122 and the torch connector 124, and / or the housing 122 and the torch connector 124 may include an insulating layer to electrically insulate the wire electrode 116 from the welding circuit.

[0044] If the welding torch 108 includes one or more drive rollers 142 to pull the wire electrode 116 to the welding torch (ie, if the system 100 is a push-pull system), the drive rollers 142 are also insulated from the welding circuit.

[0045] In the illustrated example, a voltage sensing cable 144 is connected to the wire electrode 116, for example, at a wire guide 146. The wire guide 146 receives the wire electrode 116 from the wire source 118 and guides the wire electrode to one or more drive rollers 120. The example wire guide 146 includes an inner conductive layer for guiding the wire electrode 116 and an outer insulating layer for electrically insulating the wire electrode 116 from the wire feeder frame 110. The voltage sensing cable 144 can be connected to the conductive layer of the wire guide 146. When the wire electrode 116 is electrically isolated from the welding circuit and therefore does not conduct current, the voltage at the wire electrode 116 is equal to the voltage at the contact tip 126 (or the point along the welding torch 108 where the wire electrode 116 is in electrical contact with a conductor of the welding circuit). Therefore, in the system 100, sensing the voltage at the wire electrode 116 is equivalent to (e.g., has the same measured value as) sensing the voltage at the contact tip 126 (or the point along the welding torch 108 where the wire electrode 116 is in electrical contact with a conductor of the welding circuit).

[0046] In the illustrated example, the second voltage sensing cable 145 is connected to the wire feeder frame 110 or another reference point. Although illustrated as cables, the voltage sensing cables 144 and 145 can be any conductive path electrically connected to the wire electrode 116 and the wire feeder frame. A voltmeter 150 is connected to the first voltage sensing cable 144 and the second voltage sensing cable 145. The voltmeter 150 is thus able to measure the voltage between the wire electrode 116 and the wire feeder frame 110, which is equal to the voltage between the wire feeder frame 110 and the point in the welding torch 108 where the conductor 127 contacts the wire electrode 116. Therefore, this voltage is equivalent to the voltage drop across the conductor 127 of the welding torch 108.

[0047] The voltmeter 150 can send a signal representing the voltage between the wire electrode 116 and the wire feeder frame 110 to the control circuit system 152 of the welding power source 102. The control circuit system 152 can track and use this voltage data to predict the failure mechanism of the welding torch 108. The control circuit system 152 can store data and retrieve data from a memory (e.g., a memory of the control circuit system 152). The control circuit system 152 can also determine the torch impedance based on the voltage between the wire electrode 116 and the wire feeder frame 110. The torch impedance is equal to the torch voltage (e.g., the voltage between the wire electrode 116 and the wire feeder frame 110) divided by the welding current. The control circuit system 152 controls the welding current, and therefore the welding current is a known value. Alternatively, a current sensor can measure the welding current and determine the torch impedance by dividing the measured torch voltage by the measured welding current. The control circuit system 152 can track changes in the torch impedance over time to predict the failure mechanism of the welding torch 108. The control circuit system 152 can analyze the characteristics of the welding torch impedance over time to predict the failure mechanism of the welding torch 108.

[0048] The control circuit system 152 may also store the voltage data in a memory. In some examples, the voltage sensing cables 144 , 145 send voltage sensing signals directly to the control circuit system 152 , and the control circuit system processes the signals and calculates the voltage between the electrode wire 116 and the wire feeder frame 110 .

[0049] The welding power source 102 may also include a communication circuit system 154. The communication circuit system 154 enables the control circuit system 152 to communicate with the control circuit system 156 of the wire feeder 104 via the communication circuit system 158 of the wire feeder 104. The communication circuit system 154 may also enable the control circuit system 152 to communicate with an external computing device 160 (i.e., a smartphone, a personal computer, a server, a cloud infrastructure, a robotic controller, a production cell or production line controller, etc.). The communication circuit system 154 and the communication circuit system 158 may communicate via a wired connection (e.g., via an Ethernet or serial cable, via a signal transposed on the power cable 112, etc.) or a wireless connection (e.g., Wi-Fi, Bluetooth, near-field communication, ZigBee, RuBee, or the like). The control circuit system 152 may transmit the voltage data sensed by the voltage sensing cables 144, 145 to the external computing device 160 via the communication circuit system 154. The control circuit system 152 can send commands to the wire feeder control circuit system 156 via the communication circuit system 154 to adjust the settings of the wire feeder 104 (e.g., warning display, stopping wire feeding, etc.) based on the voltage signals received from the voltage sensing cables 144, 145.

[0050] Although shown as being internal to the welding-type power supply 102, the voltmeter 150 may be external to the welding-type power supply 102. For example, the voltmeter 150 may be a separate voltmeter or may be integrated into the wire feeder 104.

[0051] Voltage data from the voltage sensing cables 144, 145 may also or alternatively be received by the control circuitry 156 of the wire feeder 104 or by an external computing device 160. For example, the voltage sensing cables 144, 145 may be connected to the control circuitry 156 of the wire feeder 104. The control circuitry 156 may determine the voltage between the wire electrode 116 and the wire feeder frame 110. The control circuitry 156 may track and use this voltage between the wire electrode 116 and the wire feeder frame to predict failure mechanisms of the welding torch 108. The control circuitry 156 may also determine the torch impedance based on the voltage between the wire electrode 116 and the wire feeder frame 110. The torch impedance is equal to the torch voltage divided by the welding current. The welding current may be a known value, or alternatively, a current sensor may measure the welding current. The torch impedance is determined by dividing the torch voltage by the measured welding current. The control circuitry 156 may track changes in the torch impedance over time to predict failure mechanisms of the welding torch 108.

[0052] Although shown as being connected to the contact tip 126 , the wire electrode 116 may make electrical contact at any point along the welding torch 108 .

[0053] Figure 2 Shows that you can Figure 1 The liner adapter 202, liner cap 204, single coil liner 206, and power pin 208 used in the welding torch 108 and cable 128 of the system 100 are shown. The liner adapter 202 can be made of any suitable electrically insulating material, such as plastic. Thus, the single coil liner 206 and the electrode wire 116 within the single coil liner 206 are insulated from the power pin 208.

[0054] The electrically insulating heat shrink 210 covers the single coil bushing 206 over the remaining length of the single coil bushing 206. Thus, the single coil bushing 206 (and therefore the wire electrode 116 within the single coil bushing 206) is insulated from the cable 128 electrically connected to the welding circuit of the welding torch 108 or any conductive components of the welding torch 108, except at the front end of the welding torch 108 (e.g., at the contact tip 126 or fixed head of the welding torch 108).

[0055] For non-ferrous wire welding, the single coil bushing 206 can be a plastic tube. In this case, the electrode wire 116 is insulated between the power pin 208 and the wire bushing. If the system includes a welding torch with a pull motor (i.e., the welding torch 108 includes one or more drive rollers 142 to pull the electrode wire 116 to the welding torch), the drive rollers 142 are also insulated from the welding circuit.

[0056] Figure 3An example embodiment of a wire guide 146 is shown that insulates the electrode wire 116 from the wire feeder frame 110. The example wire guide 146 is composed of a conductive, wear-resistant metal core tube 302 and an insulating layer 304. A voltage sensing cable 144 is electrically connected to the metal core 302 to pick up the voltage signal from the electrode wire 116. As shown, the voltage sensing cable 144 is indirectly connected to the core tube 302 via a washer 306 and a mounting 308. The wire receiving end 310 of the wire guide 146 has a taper for wire entry. In some examples, the wire receiving end can alternatively be a quick disconnect or coupler that couples to a conduit that delivers the electrode wire 116 from the wire source 118 to the wire guide 146. The core tube 302 can have a conductive single-coil spring therein as a jump liner, and the single-coil spring can extend beyond the wire receiving end 310.

[0057] The core tube 302 may also have other mechanisms to ensure that the core tube 302 is electrically connected to the electrode wire 116 so that the voltage sensing cable reads the voltage at the electrode wire 116. Such mechanisms may include floating or sliding contact mechanisms. In some examples, the wire guide 146 may include an additional metal tube layer 312 outside the insulation layer 304 to provide structural support.

[0058] Figure 4 The front end 130 of the welding torch 108 is shown, which includes a gooseneck 402, a fixed head 404, a nozzle 406, and a contact tip 126. The wire bushing includes a single coil 206 covered by an insulating heat shrink 210. As shown, the insulating wire bushing terminates at the contact tip 126. Because the wire bushing is covered by the insulating heat shrink 210, the electrode wire 116 is insulated from the conductors of the welding torch 108 except for the contact tip 126. Therefore, the voltage sense cable 144 ( Figure 1 ) The voltage signal picked up will represent the voltage at the contact point between the electrode wire 116 and the conductor of the welding torch 108, which is the rear end 408 of the contact tip 126 as shown.

[0059] If the heat shrink 210 is not extended this far and the single coil 206 contacts the fixed head 404, the point of contact between the electrode wire and the conductor of the welding torch 108 will be that point on the fixed head 404. In this case, the voltage sense cable 144 ( Figure 1 ) will represent the voltage at the point where the fixed head 404 contacts the single coil 206. Therefore, by adjusting the end of the heat shrink 210 back slightly, the voltage can be measured at any location from the rear end 408 of the contact tip 126 to the body of the welding torch 108.

[0060] return Figure 1, the voltage sensing cable 144 picks up the voltage of the electrode wire 116, which represents the voltage at the front end 130 of the welding torch 108, which is marked as the tip voltage V 端头 Although the voltage sensing cable 144 is shown as being connected to the wire 116 within the wire guide 146, the voltage sensing cable 144 can be electrically connected to the wire 116 at alternative pickup locations. For example, the voltage sensing cable can be electrically connected to one or more of the following: the drive roller 120, the inner conductor of the intermediate guide 121, the receiving portion 122, the single coil 206 of the wire bushing, the wire 116 within the conduit 117, or the wire 116 within the wire source 118.

[0061] Uecker et al. (U.S. Pat. No. 6,066,032) disclose a voltage sensing lead 162 that picks up the voltage at the front end of the torch cable 161. By using sensing lead 162 in addition to sensing leads 144 and 145, the control circuit system 152, 156 will have three voltage measurements: (1) the wire feeder frame 110 or wire feeder housing 122; (2) the front end 161 of the torch cable; and (3) the electrode wire 116 or contact tip 126. By comparing these voltage measurements, the location of a potential fault within the welding torch 108 can be more specifically located or predicted. For example, the difference between the voltage at the wire feeder frame 110 (or wire feeder housing 122) and the voltage at the front end 161 can be monitored by the control circuit system 152, 156 to identify and / or predict a fault in the cable 128. Additionally or alternatively, the difference between the voltage at the front end 161 and the voltage at the contact tip 126 may be monitored by the control circuitry 152 , 156 to identify and / or predict failure of the gooseneck and / or the fixed head of the contact tip 126 .

[0062] The voltage sense leads 144, 145, 162 and the ground sense lead 148 may be housed at the voltmeter 150 and the control circuitry 152, at the control circuitry 156, and / or shared between the control circuitry 152, 156. Additionally or alternatively, the voltage sense leads 144, 145, 162 and the ground sense lead 148 may be housed by a separate data acquisition device.

[0063] V measured by the first voltage sensing cable 144 端头 and the voltage at the wire feeder frame 110 (marked as V 送丝器 ) is equal to the torch voltage V 焊炬 The control circuitry 152 or 156 may use the determined V 焊炬 and the known welding current I 焊接 To determine the resistance R of the welding torch 焊炬 .

[0064] The control circuit system 152 or 156 monitors R during use of the welding torch 108. 焊炬 , thereby allowing the control circuit system 152 or 156 to determine the status of the welding torch 108 in real time. For data processing purposes, the average torch impedance R during a welding or welding period is 焊炬 It can also be used to determine the status of the welding torch 108.

[0065] As the conductive path 127 of the welding torch 108 (ie, the copper wire, the crimp at the joint, or other portion of the torch that carries the welding current) deteriorates, the measured impedance R 焊炬 will increase. Monitor the impedance R over time 焊炬 The control circuit system 152, 156 (or the tracking of the torch impedance R over time) 焊炬 The external computing device 160 (e.g., an external computing device 160) can predict the time of failure of the welding torch 108, predict possible failure modes, and / or schedule maintenance before the welding torch 108 fails. In some examples, the external computing device 160 schedules maintenance during planned system downtime (e.g., during a planned break) and / or based on the estimated time of failure. Thus, defects in the welding torch 108 can be repaired before they cause catastrophic damage.

[0066] The different shapes of the impedance trends over time can indicate different types of failure mechanisms. For example, different types of wear and / or failures can manifest as different rates of change of impedance (e.g., impedance slopes). For example, the gradual degradation of copper wire has a specific range of impedance slopes. Sudden loose connections (such as between the contact tip 126 and the fixed head 404, between the fixed head 404 and the gooseneck 402, between the gooseneck 402 and the torch body, and / or between the power pin 208 and the wire feeder housing 122) can each have specific (multiple) impedance time characteristics that can be identified to predict a specific type of failure that may occur (or has occurred). By identifying these (multiple) impedance time slopes and / or (multiple) characteristics during operation, the control circuit system 152, 156 and / or the external computing device 160 can determine the failure mechanism and alert the relevant technician to perform preventive maintenance and / or guide repairs.

[0067] In some examples, the welding torch 108 can include an RFID tag that includes initial torch impedance information. An RFID reader within the wire feeder 104 can read the RFID tag and determine the initial torch impedance. During operation, the control circuit system 152 or 156 can compare the actual torch impedance to the initial torch impedance and, when the actual torch impedance has increased by a threshold amount from the initial torch impedance, the control circuit system determines that the welding torch 108 requires maintenance.

[0068] In some examples, a user can input the type of welding torch into the user interface 159 of the wire feeder 104, the user interface 153 of the welding power source 102, or the external computing device 160. The control circuit system 152 or 156 then retrieves the initial torch impedance from the memory based on the input torch type. Then, during operation, the control circuit system 152 or 156 can compare the actual torch impedance with the initial torch impedance and, when the actual torch impedance has increased by a threshold amount from the initial torch impedance, the control circuit system determines that the welding torch 108 requires maintenance.

[0069] Figure 5 is a flow chart representing example machine-readable instructions 500 that may be executed by Figure 1 The machine readable instructions 500 may be executed in part or in whole by the system 100 to determine the torch impedance. Figure 1 The control circuit system 152 or 156 is implemented.

[0070] At block 502, the control circuitry 152 receives a signal indicative of a welding current. In some examples, the welding current is controlled by the welding power source 102, such that the control circuitry 152 retrieves a known welding current value. In some examples, the welding current is measured by a current sensor that sends a signal indicative of the measured welding current to the control circuitry 152.

[0071] At block 504, the control circuit system 152 receives a signal from the first voltage sensing lead 144 indicating the voltage measured at the wire electrode 116. At block 506, the control circuit system 152 receives a signal from the second voltage sensing lead 145 indicating the voltage measured at a reference point (e.g., the wire feeder frame 110). At block 508, the control circuit system 152 calculates the voltage of the welding torch 108, where the voltage of the welding torch 108 is equal to the voltage difference between the wire feeder frame 110 and the wire electrode 116. At block 510, the control circuit system 152 calculates the torch impedance, where the torch impedance is equal to the torch voltage calculated at block 508 divided by the welding current indicated at block 502.

[0072] Figure 6 is a flow chart representing example machine-readable instructions 600 that may be executed by Figure 1 The system 100 is executed to determine whether the welding torch has failed based on the welding torch impedance. The machine readable instructions 600 may be partially or completely executed by Figure 1 The control circuit system 152 or 156 is implemented.

[0073] At block 602, the control circuitry 152 uses, for example, Figure 5The method 500 of determining the impedance of the welding torch 108. At block 604, the control circuit system 152 retrieves a threshold impedance from the memory, which is an impedance indicating that the welding torch 108 has failed or requires maintenance. In some examples, the user can enter the threshold impedance into the user interface 159 of the wire feeder 104, the user interface 153 of the welding power supply 102, or the external computing device 160. In some examples, the user enters the torch type into the user interface (153, 159, 160), and the control circuit system 152 retrieves the threshold impedance from the memory based on the torch type. The memory may include a database that associates the torch type with the threshold impedance. In some examples, the torch may have an RFID tag that is scanned by an RFID reader located at the wire feeder 104. The RFID tag may include information indicating the threshold impedance, which may be sent to the control circuit system 152 and stored in the memory. In some examples, the RFID tag indicates the torch type, and the control circuit system 152 retrieves the threshold impedance from the memory based on the torch type.

[0074] At block 606, the control circuit system 152 compares the torch impedance determined at block 602 with a threshold impedance. If the torch impedance meets the threshold impedance (e.g., exceeds the threshold) (block 606), then at block 608, the control circuit system 152 outputs a signal indicating that the welding torch 108 has failed or requires maintenance. The control circuit system 152 may output a signal indicating that the welding torch has failed or requires maintenance to the user interface 159 of the wire feeder 104, the user interface 153 of the welding power source 102, or the external computing device 160. In some examples, the control circuit system 152 may disable the system 100 (e.g., send a signal to disable power to the welding torch 108, send a signal to cut off power to the wire feeder 104, send a signal to stop wire feeding, etc.) until the welding torch 108 has been replaced or repaired. In some examples, the control circuit system 152 may send a signal to the external computing device 160 via the communication circuit system 154 to schedule maintenance on the welding torch 108.

[0075] In some examples, if the torch impedance does not meet the threshold impedance (block 606), then at block 610, the control circuit system 152 calculates the remaining life of the torch 108, where the remaining life may correspond to a usage time. Figure 7As explained, the control circuit system 152 can calculate the remaining life of the welding torch based on the trend of the welding torch impedance and the threshold impedance. At block 612, the control circuit system sends a signal indicating the remaining torch life calculated at block 610. This signal can be sent to the user interface 159 of the wire feeder 104, the user interface 153 of the welding power supply 102, or the external computing device 160. Determining the useful remaining life can be advantageous, for example, because the control circuit system can send a signal to schedule maintenance on the welding torch 108 before the welding torch fails and preferably during a planned system downtime.

[0076] Figure 7 is a flow chart representing example machine-readable instructions 700 that may be executed by Figure 1 The system 100 is executed to determine the remaining life of the welding torch based on the welding torch impedance. The machine readable instructions 700 may be partially or completely executed by Figure 1 The control circuit system 152 or 156 is implemented.

[0077] At block 702, the control circuitry 152 uses, for example, Figure 5 The method 500 determines the impedance of the welding torch 108. At block 704, the control circuit system 152 retrieves the torch impedance measurement previously stored in the memory. The control circuit system 152 may obtain samples of the torch impedance at a specific sampling rate and store these samples in the memory.

[0078] At block 706, control circuitry 152 determines the slope of the impedance with respect to usage time. In some examples, control circuitry 152 determines the slope of a line that approximates a line that would pass through the impedance samples if plotted against usage time (i.e., the usage time at which each sample was acquired). In some examples, control circuitry 152 may use only the most recent X number of impedance samples, where X may be one sample, two samples, three samples, etc.

[0079] At block 708, the control circuitry 152 retrieves the threshold impedance from memory.At block 710, the control circuitry calculates the difference between the torch impedance determined at block 702 and the threshold impedance.

[0080] At block 712, the control circuitry 152 determines the remaining time of use of the torch 108 based on: 1) the difference between the torch impedance and the threshold impedance, and 2) the slope of the impedance with respect to time of use. For example, if the difference between the torch impedance and the threshold impedance is 2×10 -3 Ohms, and the slope of impedance relative to usage time is 2×10 per hour -5 , the remaining usage time is 100 hours.

[0081] Figure 8is a flow chart representing example machine-readable instructions 800 that may be executed by Figure 1 The machine readable instructions 800 may be executed in part or in whole by the system 100 to determine the failure mechanism of the welding torch. Figure 1 The control circuit system 152 or 156 is implemented.

[0082] At block 802, the control circuitry 152 uses, for example, Figure 5 The method 500 of FIGURE 5 determines the impedance of the welding torch 108. At block 804, the control circuit system 152 retrieves the torch impedance measurement previously stored in memory. At block 806, the control circuit system 152 determines the slope of the impedance with respect to usage time. In some examples, the control circuit system finds the slope of a line that approximates a line that would pass through the impedance samples drawn against usage time (i.e., the usage time when each sample was taken). In some examples, the control circuit system 152 may only use the most recent X number of impedance samples, where X may be one sample, two samples, three samples, etc. At block 808, the control circuit system 152 retrieves a threshold slope from memory.

[0083] At block 810, the control circuit system 152 compares the determined impedance and / or slope to a first threshold. If the impedance and / or slope is less than the first threshold, then at block 812, the control circuit system 152 determines that the torch has not failed (i.e., is acceptable). The torch returns to block 802 to continue monitoring the torch slope and impedance.

[0084] If the impedance and / or slope do meet the first threshold (block 810), then at block 814, the control circuit system 152 compares the impedance and / or slope to a second threshold. If the impedance and / or slope do not meet the second threshold (block 814), then at block 816, the control circuit system 152 determines that the welding torch 108 has failed via a first mechanism. The first mechanism can be, for example, a loose connection within a conductor or a broken conductor. If the impedance and / or slope meet the second threshold (block 814), then at block 818, the control circuit system determines that the welding torch has failed via a second failure mechanism. For example, the second failure mechanism can be conductor degradation or insulation damage.

[0085] At block 820, the control circuit system 152 sends a signal indicating the type of torch fault determined at blocks 810 to 818. This signal may cause a user interface at the wire feeder 104, a user interface at the welding power source 102, or an external computing device 160 to indicate the fault mechanism to a user. The control circuit system 152 may also send a signal to the external computing device 160 via the communication circuit system 154 to schedule maintenance on the welding torch 108 based on the determined type of fault.

[0086] Although the machine-readable instructions 800 include two fault mechanisms, more impedance and / or slope thresholds and fault types may be associated and implemented by the control circuitry.

[0087] The impedance and / or slope in the disclosed examples can be from V 焊炬 and / or R 焊炬 Other criteria derived from the data, such as R 焊炬 In some examples, the control circuit system 152 may also determine the rate of change of the slope and determine the fault type based on the rate of change of the slope by comparing the rate of change of the slope to a threshold slope rate of change, similar to the reference Figure 8 Described method.

[0088] In some examples, the control circuitry 152 may plot the impedance samples against time of use to determine the shape of a trend line for the impedance samples. The control circuitry may then compare the shape of the plotted trend line with trend lines stored in memory, where the trend lines stored in memory correspond to specific failure mechanisms of the welding torch. The control circuitry may determine the type of failure by determining which trend line retrieved from memory the actual trend line most resembles.

[0089] Although the examples are disclosed above with reference to GMAW, the disclosed examples may be modified to use other wire feeding processes, such as flux-cored arc welding (FCAW).

[0090] Although 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 present method and / or system. For example, the frames and / or components of the disclosed examples may be combined, divided, rearranged and / or otherwise modified. In addition, many modifications may be made to adapt specific circumstances or materials to the teachings of the present disclosure without departing from the scope of the present disclosure. Therefore, the present method and / or system is not limited to the specific embodiments disclosed. On the contrary, the present method and / or system will include all embodiments that fall within the scope of the appended claims, both literally and according to the doctrine of equivalents.

Claims

1. A welding system comprising: a welding torch including a contact tip configured to conduct a welding-type current to a wire electrode; a conductive path configured to deliver welding power from a welding-type power supply to the contact tip; a wire feeder including a receiving portion configured to: transmit the welding-type current to the welding torch via a torch connector and position the torch connector to receive the electrode wire; an electrically isolated path configured to deliver the electrode wire from a wire source to the contact tip; as well as A control circuit system is configured to determine or obtain a first voltage or a first impedance between the fixed head or the contact end of the welding torch and the housing or the frame surrounding the wire feeder, a second voltage or a second impedance between the fixed head or the contact end of the welding torch and the front end of the cable of the welding torch, and a third voltage or a third impedance between the fixed head or the contact end of the welding torch and the gooseneck of the welding torch.

2. The welding system according to claim 1, The wire feeder further comprises one or more drive rollers configured to drive the electrode wire to the welding torch, wherein the one or more drive rollers are electrically insulated from the frame.

3. The welding system of claim 1 , further comprising a control circuit system configured to determine at least one state of the welding torch based on the first voltage, the second voltage, or the third voltage or the first impedance, the second impedance, or the third impedance.

4. The welding system of claim 1 , further comprising a control circuit system configured to determine the first impedance, the second impedance, or the third impedance based on a result of dividing the first voltage, the second voltage, or the third voltage by the measured welding-type current.

5. The welding system of claim 1 , further comprising a control circuit system configured to: comparing the first impedance, the second impedance, or the third impedance to a first threshold impedance, a second threshold impedance, or a third threshold impedance; and A signal is output when the first impedance, the second impedance, or the third impedance exceeds the first threshold impedance, the second threshold impedance, or the third threshold impedance.

6. The welding system of claim 5, wherein the signal provides an alert to an operator.

7. The welding system of claim 5, wherein the signal comprises a command to cut off the welding power supplied to the welding torch, cut off the welding power supplied to the wire feeder, or shut down the wire feeder.

8. The welding system of claim 1 , further comprising a control circuit system configured to: monitoring a change in the first impedance, the second impedance, or the third impedance; and A type of torch failure is predicted based on the changes.

9. The welding system of claim 8, wherein the type of the torch fault is one of a broken conductor in the cable of the welding torch, a loose connection between components, improper installation of components, deterioration of a rotational connection, or insulation damage fault.

10. The welding system of claim 1 , further comprising control circuitry configured to: monitoring a rate of increase of the first impedance, the second impedance, or the third impedance; and A type of torch failure is predicted based on the rate.

11. The welding system of claim 1 , further comprising a control circuit system configured to: monitoring a change in the first impedance, the second impedance, or the third impedance; and A failure time is predicted based on the changes.

12. The welding system of claim 1 , comprising a wire guide configured to receive the electrode wire and guide the electrode wire to one or more drive rollers, the wire guide comprising: a conductive layer configured to guide the electrode wire; as well as An insulating layer is configured to electrically insulate the wire electrode and the conductive layer from the frame.

13. The welding system of claim 12, wherein the wire guide comprises a single coil spring.

14. The welding system of claim 1 , further comprising control circuitry configured to: comparing the first voltage or the first impedance between the fixed head or the contact tip of the welding torch and the housing or the frame surrounding the wire feeder, and the second voltage or the second impedance between the fixed head or the contact tip of the welding torch and the front end of the cable of the welding torch to one or more threshold voltages or threshold impedances; determining or predicting a location of a fault in the welding torch based on the comparison; and A signal indicative of the fault is output.

15. A welding system comprising: a welding torch comprising a contact tip configured to conduct a welding-type current to a wire electrode; a conductive path configured to deliver welding power from a welding-type power supply to the contact tip; a wire feeder including a receiving portion configured to: transmit the welding-type current to the welding torch via a torch connector and position the torch connector to receive the electrode wire; an electrically isolated path configured to deliver the electrode wire from a wire source to the contact tip; as well as A control circuit system is configured to determine or obtain a first voltage or a first impedance between the housing or the frame surrounding the wire feeder and the fixed head or the contact end of the welding torch, a second voltage or a second impedance between the housing or the frame surrounding the wire feeder and the front end of the cable of the welding torch, and a third voltage or a third impedance between the housing or the frame surrounding the wire feeder and the gooseneck of the welding torch.

16. A wire feeder comprising: frame; a receiving portion configured to: transmit a welding-type current to a welding torch via a torch connector and to position the torch connector to receive a wire electrode; one or more drive rollers configured to drive the wire electrode to the welding torch, the one or more drive rollers being electrically insulated from the frame, and wherein the wire electrode is electrically insulated from the frame; as well as A control circuit system is configured to determine or obtain a first voltage or a first impedance between the fixed head or the contact end of the welding torch and the housing or the frame surrounding the wire feeder, a second voltage or a second impedance between the fixed head or the contact end of the welding torch and the front end of the cable of the welding torch, and a third voltage or a third impedance between the fixed head or the contact end of the welding torch and the gooseneck of the welding torch.

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