KR102093528B1 - Method of and system for starting and using in combination a filler wire feed and arc generating source for welding - Google Patents

Abstract

Working with an arc-generating power supply 2130 for generating a weld puddle and at least one resistive filler wire 140 heated to or near the melting temperature and deposited into the weld puddle Methods and systems for welding or bonding water 115 are disclosed.

Description

METHOD OF AND SYSTEM FOR STARTING AND USING IN COMBINATION A FILLER WIRE FEED AND ARC GENERATING SOURCE FOR WELDING}

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This application is incorporated herein by reference in its entirety, and is a portion of the United States Patent Application Serial No. 12 / 352,667, filed January 13, 2009, incorporated herein by reference in its entirety, in 2011 It is a continuing part of U.S. Patent Application No. 13 / 212,025, filed on August 17, and claims priority to it.

Certain embodiments relate to filler wire overlaying applications as well as welding and joining applications. More specifically, certain embodiments are for any of brazing, cladding, building up, filling, hard-facing overlaying, bonding and welding applications. A system and method for initiating and using a combination filler wire supply and energy source system.

The filler wire method of conventional welding (e.g., gas-tungsten arc welding (GTAW) filler wire method) has increased deposition rate and welding speed compared to traditional single arc welding. ). The filler wire preceding the torch is resistance-heated by a separate power supply. The wire is fed through a contact tube towards the workpiece and extends beyond the tube. The elongated one can be resistance-heated as it approaches the puddle. Tungsten electrodes can be used to heat and melt the workpiece to form a weld puddle. A power supply provides much of the energy needed to resistance-melt the filler wire. In some cases, the wire supply can slide or shake, and the current in the wire can generate an arc between the tip of the wire and the workpiece. The extra heat of such arcs can lead to burnthrough, spatter and poor surface quality. The risk of such arcing is greater at the start of the process where the wire initially comes into contact with the workpiece at a small point. If the initial current in the wire is too high, the point may burn out and generate an arc.

Additional limitations and disadvantages of the conventional, traditional and proposed approaches, by comparing those approaches and embodiments of the present invention stated in the rest of the present application, with reference to the drawings, of the technical field to which the present invention pertains. It will be clear to the skilled person.

Embodiments of the present invention include systems and methods for initiating and using combination filler wire feeders and energy source systems. The first embodiment of the present invention provides a method for initiating and using a combination wire supply and energy source system for any of soldering, cladding, building up, filling, surface hardening overlay, welding and bonding applications. The method includes applying a sensing voltage between at least one resistive filler wire and a work piece through a power source and advancing the distal end of the at least one resistive filler wire toward the work piece. The method further includes detecting when the distal end of the at least one resistive filler wire contacts the work piece. The method also includes powering off the at least one resistive filler wire over a defined time interval in response to the sensing. The method further includes turning on the power at the end of the defined time interval to apply a flow of heating current through at least one resistive filler wire. The method also includes applying energy from the high intensity energy source to the workpiece to heat the workpiece while at least applying the flow of heating current. The high intensity energy source is a laser device, plasma arc welding (PAW) device, gas tungsten arc welding (GTAW) device, gas metal arc welding (GMAW) device, flux core At least one of a flux cored arc welding (FCAW) device, and a submerged arc welding (SAW) device. The details of these and other features of the claimed invention, as well as the illustrated embodiments thereof, will be more fully understood from the following description, claims and drawings.

1 shows a functional schematic block diagram of an exemplary embodiment of a combination filler wire feeder and energy source system for any of soldering, cladding, building up, filling, and surface hardening overlay applications;
2 shows a flow diagram of an embodiment of the start-up method used by the system of FIG. 1;
3 shows a flow diagram of an embodiment of a post start-up method used by the system of FIG. 1;
4 shows a first exemplary embodiment of a pair of voltage and current waveforms associated with the method after initiation of FIG. 3;
FIG. 5 shows a second exemplary embodiment of a pair of voltage and current waveforms associated with the method after initiation of FIG. 3;
6 and 6A show another exemplary embodiment of the present invention used to perform a welding operation;
7, 7A and 7B show additional embodiments of welding with the present invention;
8 shows another exemplary embodiment of joining two sides of a joint at the same time;
9 shows another exemplary embodiment of welding with the present invention;
10 shows another exemplary embodiment of the invention for welding a joint with multiple lasers and wires;
11A-11C show exemplary embodiments of contact tips used with embodiments of the present invention;
12 shows a hot wire power supply system according to embodiments of the present invention;
13A-13C show voltage and current waveforms generated by exemplary embodiments of the present invention;
14 shows another welding system according to an exemplary embodiment of the present invention;
15 shows an exemplary embodiment of a weld puddle produced by an embodiment of the present invention;
16A-16F illustrate exemplary embodiments of welding puddle and laser beam utilization according to embodiments of the present invention;
17 shows a welding system according to another exemplary embodiment of the present invention;
18 shows an exemplary embodiment of a ramp down circuit that can be used in embodiments of the present invention;
19 shows an exemplary embodiment of a fume extraction nozzle according to the present invention;
20 shows an exemplary embodiment of another welding system of the present invention;
21 shows an exemplary embodiment of a welding operation according to an embodiment of the invention;
22A-22C show exemplary embodiments of current waveforms used by the welding systems of the present invention;
23 shows an exemplary embodiment of another welding operation according to an embodiment of the present invention;
24 shows another exemplary embodiment of current waveforms that can be used with embodiments of the present invention;
25 shows an exemplary embodiment of another welding operation that can be used with embodiments of the present invention;
25A shows an exemplary embodiment of current waveforms that can be used with the embodiment shown in FIG. 25;
26 shows an exemplary embodiment of another welding operation using a side-by-side arc welding operation;
27 shows an exemplary embodiment of an additional welding operation of the present invention; And
28 shows a further exemplary embodiment of the welding operation of the present invention using magnetic steering.

The term "overlaying" is used herein in a wide variety of ways and includes brazing, cladding, building up, filling, and hard-facing. It can mean any application. For example, in "soldering" applications, filler metal is distributed between closely mated surfaces of the joint through capillary action. On the other hand, in "braze welding" applications, the filler metal is allowed to flow into the gap. In this specification, however, both techniques are broadly referred to as overlaying applications.

1 is a functional schematic block diagram of an exemplary embodiment of a combination filler wire feeder and energy source system 100 for performing any of soldering, cladding, building up, filling, surface hardening overlay, and bonding / welding applications. City. The system 100 includes a laser subsystem capable of focusing the laser beam 110 onto the work piece 115 to heat the work piece 115. The laser subsystem is a high intensity energy source. The laser subsystem is any type of high energy laser, including but not limited to carbon dioxide, Nd: YAG, Yb-disc, YB-fiber, fiber delivery or direct diode laser systems. It can be a sauce. In addition, white light or quartz laser-type systems can also be used if they have sufficient energy. Other embodiments of the system include an electron beam, plasma arc welding subsystem, gas tungsten arc welding subsystem, gas metal arc welding subsystem, flux cored arc welding subsystem, serving as the high intensity energy source. , And at least one of a submerged arc welding subsystem. In the following specification, the laser system, beam and power supply will be mentioned repeatedly, however, it should be understood that this reference is exemplary as any high intensity energy source may be used. For example, a high intensity energy source can provide at least 500 W / cm 2. The laser subsystem includes a laser device 120 and a laser power supply 130 that are operatively connected to each other. The laser power supply 130 provides power to operate the laser device 120.

The system 100 can also provide a hot filler wire feeder subsystem capable of providing at least one resistive filler wire 140 to contact the work 115 near the laser beam 110. It includes. Of course, referring to the work 115 herein, the molten puddle is considered to be a part of the work 115, so contact with the work 115 is in contact with the puddle. You will understand that it contains. The hot filler wire feeder subsystem includes a filler wire feeder 150, a contact tube 160, and a hot wire power supply 170. During operation, the filler wire 140, which precedes the laser beam 110, is from the hot wire welding power supply 170 that is operatively connected between the contact tube 160 and the workpiece 115. Resistance-heated by the current of According to an embodiment of the present invention, the hot wire welding power supply 170 is a pulsed direct current (DC) power supply, but alternating current (AC) or other types of power supplies It is also possible. The wire 140 is supplied to the work 115 from the filler wire feeder 150 through the contact pipe 160 and extends beyond the pipe 160. The extension portion of the wire 140 is resistance-heated such that the extension portion approaches or reaches the melting point before contacting the welding puddle on the workpiece. The laser beam 110 melts a portion of the base metal of the workpiece 115 to form a welding puddle and also melt the wire 140 onto the workpiece 115. Plays a role. The power supply 170 provides much of the energy required to resistance-melt the filler wire 140. According to certain other embodiments of the present invention, the feeder subsystem may be capable of providing one or more wires simultaneously. For example, a first wire can be used to hard-facing the workpiece and / or to provide corrosion resistance to the workpiece, and the second wire provides structure to the workpiece. It can be used to add.

The system 100 includes the laser beam 110 (an energy source) and the resistive filler wire 140 such that the laser beam 110 and the resistive filler wire 140 remain fixed relative to each other. It further includes a motion control subsystem capable of moving (at least in a relative sense) the same direction 125 along the work 115. According to various embodiments, the relative motion between the workpiece 115 and the laser / wire combination is actually by moving the workpiece 115 or by moving the laser device 120 and the hot wire feeder subsystem. Can be achieved. In FIG. 1, the motion control subsystem includes a motion controller 180 that is operatively connected to the robot 190. The operation controller 180 controls the operation of the robot 190. The robot 190, the laser beam 110 and the wire 140, the work to move the work 115 in the direction 125, so as to effectively move along the work 115 It is operatively connected to water 115 (eg mechanically fixed). According to an alternative embodiment of the present invention, the laser device 110 and the contact tube 160 may be integrated into a single head. The head is a motion control sub which is operatively connected to the head. It can be moved along the work 115 through the system.

In general, there are several ways that a high intensity energy source / hot wire can be moved relative to the work piece. When the workpiece is circular, for example, the high intensity energy source / hot wire is stationary and the workpiece can be rotated under the high intensity energy source / hot wire. Alternatively, a robot arm or linear tractor can move parallel to the circular workpiece, and as the workpiece rotates, the high intensity energy source / hot wire, for example, To overlay the surface of the circular workpiece, it can be moved continuously or at one index per revolution. When the workpiece is flat or at least not circular, as shown in FIG. 1, the workpiece can be moved under the high intensity energy source / hot wire. However, a robot arm or linear tractor or even a beam-mounted carriage can be used to move the high-intensity energy source / hot wire head relative to the workpiece.

The system 100 is operatively connected to the workpiece 115 and the contact tube 160 (ie, effectively connected to the output of the hot wire power supply 170) and the workpiece 115 A sensing and current control subsystem capable of measuring the potential difference (i.e., voltage (V)) between the hot wire 140 and the current (I) passing through the workpiece 115 and the hot wire 140 ( 195). The sensing and current control subsystem 195 may be further capable of calculating a resistance value (R = V / I) and / or a power value (P = V * I) from the measured voltage and current. In general, when the hot wire 140 is in contact with the work 115, the potential difference between the hot wire 140 and the work 115 is 0 volt or almost 0 volt. Consequently, as described in more detail later in this specification, the sensing and current control subsystem 195 can detect when the resistive filler wire 140 is in contact with the work piece 115, and It is operatively connected to the hot wire power supply 170 to further control the flow of current through the resistive filler wire 140 in response to sensing. According to another embodiment of the present disclosure, the sensing and current controller 195 may be an integral part of the hot wire power supply 170.

According to an embodiment of the present invention, the operation controller 180 may be further operatively connected to the laser power supply 130 and / or the sensing and current controller 195. In this way, the operation controller 180 and the laser power supply 130 are configured so that the laser power supply 130 knows when the workpiece 115 moves and the operation controller 180 The laser devices 120 may communicate with each other to know whether they are activated. Similarly, in this way, the motion controller 180 and the sense and current controller 195 allow the sense and current controller 195 to know when the workpiece 115 moves and the motion controller ( 180) may communicate with each other to know whether the hot filler wire feeder subsystem is active. Such communications can be used to coordinate activities between the various subsystems of the system 100.

2 is a flow diagram of an embodiment of a start-up method 200 used by the system 100 of FIG. 1. In step 210, a sensing voltage is applied between the at least one resistive filler wire 140 and the work 115 through the power supply 170. The sensing voltage may be applied by the hot wire power supply 170 under the command of the sensing and current controller 195. Further, according to an embodiment of the present invention, the applied sensing voltage does not provide enough energy to significantly heat the wire 140. In step 220, the distal end of the at least one resistive filler wire 140 is advanced toward the workpiece 115. The advancing is performed by the wire feeder 150. In step 230, it is detected when the distal end of the at least one resistive filler wire 140 first contacts the workpiece 115. For example, the sensing and current controller 195 allows the hot wire power supply 170 to provide a very low level of current (eg, 3 amps to 5 amps) through the hot wire 140. I can order. Such detection is about 0 volts (e.g., 0.4) between the filler wire 140 and the workpiece 115 (e.g., through the contact tube 160) and the current controller 195. It can be achieved by measuring the potential difference of V). When the distal end of the filler wire 140 is shorted to the workpiece 115 (ie, in contact with the workpiece), between the filler wire 140 and the workpiece 115 (over 0 volts) ) Significant voltage levels may not exist.

In step 240, the power supply 170 is turned off for the at least one resistive filler wire 140 over a defined time interval (eg, several milliseconds) in response to the sensing. The sensing and current controller 195 may command the power supply 170 to be turned off. In step 250, the power supply 170 is turned on at the end of the defined time interval to apply a flow of heating current through the at least one resistive filler wire 140. The sensing and current controller 195 may command the power supply 170 to be turned on. In step 260, energy from a high intensity energy source 110 is applied to the work 115 to heat the work 115 while at least applying the flow of heating current.

Optionally, the method 200 stops the advancement of the wire 140 in response to the detection, restarting the advancement of the wire 140 at the end of the defined time interval (ie, re-advance ( re-advancing), and checking whether the distal end of the filler wire 140 is still in contact with the workpiece 115 before applying the flow of the heating current. The sensing and current controller 195 may instruct the wire supply 150 to stop supplying and instruct the system 100 to wait (eg, several milliseconds). In such an embodiment, the sensing and current controller 195 is operatively connected to the wire supply 150 to instruct the wire supply 150 to start and stop. In the sensing and current controller 195, the hot wire power supply 170 supplies the heating current to heat the wire 140 and supply the wire 140 back to the work 115. It can be ordered to authorize.

Once the initiation method is complete, the system 100 may perform the soldering application, cladding application, build-up application, surface hardening application, or welding / bonding operation to perform the laser beam 110 and hot wire. The 140 may enter a post start-up mode of the work being moved in relation to the work 115. 3 shows a flow diagram of an embodiment of a post-startup method 300 used by the system 100 of FIG. 1. In step 310, the distal end of at least one resistive filler wire 140 is preceded or coincident with a high intensity energy source (e.g., laser device 120) such that the at least one resistive filler wire 140 is in operation. As supplied toward water 115, the high intensity energy source (eg, laser device 120) and / or the heated workpiece 115 (ie, the workpiece 115 is a laser beam 110) The high energy source (eg, the laser beam 110) to melt the distal end of the filler wire 140 onto the workpiece 115. For example, the laser device 120 and the at least one resistive filler wire 140 are moved along the work 115. The operation controller 180 instructs the robot 190 to move the work 115 relative to the laser beam 110 and the hot wire 140. The laser power supply 130 provides power to operate the laser device 120 to form the laser beam 110. The hot wire power supply 170 provides current to the hot wire 140 as commanded by the sensing and current controller 195.

In step 320, the distal end of the at least one resistive filler wire 140 is detected whenever contact with the work 115 is to be broken (i.e., provides a prediction capability) . Such a detection is the rate of change of the potential difference between the filler wire 140 and the work 115 (dv / dt), the rate of change of current through them (di / dt), the rate of change of resistance between them (dr / dt), or It can be achieved by the sensing circuit measuring the rate of change of one of the rate of change of power (dp / dt) through and the prediction circuit in the current controller 195. If the rate of change exceeds a predefined value, the sensing and current controller 195 formally foresees that the contact is about to break. Such predictive circuits are well known in the art for arc welding.

When the distal end of the wire 140 melts significantly due to heating, the distal end may begin to be pinched off from the wire 140 onto the workpiece 115. For example, at that time, the potential difference or voltage increases because its cross section rapidly decreases as the distal end of the wire is pinched off. Therefore, by measuring such a rate of change, the system 100 can predict when the distal end is pinched off and the contact with the work piece 115 is about to break. In addition, when the contact is completely broken, a potential difference (i.e., voltage level) significantly greater than 0 volts can be measured by the sensing and current controller 195. If no action is taken at step 330, this potential difference can create an (undesired) arc between the new end of the wire 140 and the workpiece 115. Of course, in other embodiments, the wire 140 may not exhibit any apparent pinching, but instead will flow into the puddle in a continuous manner while maintaining a substantially constant cross-section into the puddle.

In step 330, the heating current through the at least one resistive filler wire 140 in response to detecting that the at least one resistive filler wire 140 is about to break contact with the work 115. Turn off the flow of (or at least significantly, for example, decrease by 95%). When the sensing and current controller 195 determines that the contact is about to break, the controller 195 blocks the current supplied to the hot wire 140 by the hot wire power supply 170 ( Or at least significantly). In this way, the formation of unwanted arcs is prevented and any unwanted effects such as splatter or burnthrough are prevented from occurring.

In step 340, whenever the distal end of the at least one resistive filler wire 140 continues to contact the workpiece 115 due to the wire 140 continuously advancing towards the workpiece 115. Detect. Such sensing is achieved by the sensing and current controller 195 measuring a potential difference of about 0 volts between the filler wire 140 (eg, passing through the contact tube 160) and the workpiece 115. Can be. When the distal end of the filler wire 140 is shorted to the workpiece 115 (ie, in contact with the workpiece), a significant over 0 volt between the filler wire 140 and the workpiece 115 The voltage level may not exist. The phrase “again makes contact” herein refers to whether or not the distal end of the wire 140 is actually completely pinched off from the workpiece 115, or the wire 140 is the job. It is used to refer to a situation in which the measured voltage between the wire 140 (passing through the contact tube 160) and the workpiece 115 advances toward the water 115 is about 0 volts. In step 350, the flow of the heating current is re-applied (re-) through the at least one resistive filler wire in response to detecting that the distal end of the at least one resistive filler wire contacts the workpiece again. apply). The sensing and current controller 195 may instruct the hot wire power supply 170 to reapply the heating current to continue heating the wire 140. This process can continue while the overlaying application continues.

For example, FIG. 4 shows a first exemplary embodiment of a pair of voltage and current waveforms 410 and 420 associated with method 300 after initiation of FIG. 3, respectively. The voltage waveform 410 is measured by the sensing and current controller 195 between the contact tube 160 and the workpiece 115. The current waveform 420 is measured by the sensing and current controller 195 through the wire 140 and the work 115.

Whenever the distal end of the resistive filler wire 140 is about to break contact with the work piece 115, the rate of change of the voltage waveform 410 (ie, dv / dt) will exceed a predetermined limit value. , Will indicate that a pinch-off is about to occur (see slope at point 411 of the waveform 410). As alternatives, the rate of change of current (di / dt) through the filler wire 140 and the work piece 115, the rate of change of resistance between them (dr / dt), or the rate of change of power through them (dp / dt) It can be used instead to indicate that a pinch-off is about to occur. Such rate of change prediction techniques are well known in the art. At that point, the sensing and current controller 195 will instruct the hot wire power supply 170 to turn off (or at least significantly reduce) the flow of the current through the wire 140.

The sensing and current controller 195 is in good contact with the workpiece 115 again after some time interval 430 of the distal end of the filler wire 140 (eg, the voltage level is a point When sensing at 412 again falling to about 0 volts), the sensing and current controller 195 allows the hot wire power supply 170 to flow the current through the resistive filler wire 140. Instructs to ramp up to the predetermined output current level 450 (see ramp 425). According to an embodiment of the invention, the ramp-up starts at a set point value 440. As the energy source 120 and wire 140 move relative to the work 115 and as the wire 140 advances toward the work 115 due to the wire feeder 150 This process is repeated. In this way, the contact between the distal end of the wire 140 and the work 115 is generally maintained, and arcing between the distal end of the wire 140 and the work 115 is prevented. The ramping of the heating current helps to prevent unintended interpretation of the rate of change of the voltage as a pinch-off condition or arcing condition, in the absence of this condition. Any large change in current can cause incorrect voltage readings to be taken due to inductance in the heating circuit. When the current gradually ramps up, the effect of inductance is reduced.

5 shows a second exemplary embodiment of a pair of voltage and current waveforms 510 and 520 associated with the post-initiation method of FIG. 3, respectively. The voltage waveform 510 is measured by the sensing and current controller 195 between the contact tube 160 and the workpiece 115. The current waveform 520 is measured by the sensing and current controller 195 through the wire 140 and the work 115.

Whenever the distal end of the resistive filler wire 140 attempts to break contact with the work 115, the rate of change (ie, dv / dt) of the voltage waveform 510 will exceed a predetermined limit value. Will indicate that a pinch off is about to occur (see slope at point 511 of waveform 510 above). As alternatives, the rate of change of current (di / dt) through the filler wire 140 and the work piece 115, the rate of change of resistance between them (dr / dt), or the rate of change of power through them (dp / dt) It can be used instead to indicate that a pinch-off is about to occur. Such rate of change prediction techniques are well known in the art. At that point, the sensing and current controller 195 will instruct the hot wire power supply 170 to turn off (or at least significantly reduce) the flow of the current through the wire 140.

The sensing and current controller 195 is in good contact with the workpiece 115 again after some time interval 530 of the distal end of the filler wire 140 (eg, the voltage level is a point When sensing at (512) again falling to about 0 volts, the sensing and current controller 195 detects the flow of heating current through the resistive filler wire 140 by the hot wire power supply 170. Command (see heating current level 525). As the energy source 120 and wire 140 move relative to the work 115 and as the wire 140 advances toward the work 115 due to the wire feeder 150 This process is repeated. In this way, the contact between the distal end of the wire 140 and the work 115 is generally maintained, and arcing between the distal end of the wire 140 and the work 115 is prevented. Since the heating current is not slowly ramped in this case, certain voltage readings can be ignored as unintended or wrong due to inductance in the heating circuit.

In summary, a method and system for initiating and using a combination wire supply and energy source system for any of soldering, cladding, no building, filling, and surface hardening overlay applications is disclosed. High intensity energy is applied onto the workpiece to heat it. One or more resistive filler wires are supplied to the work piece to the applied high intensity energy or immediately before the high intensity energy. Sensing is performed when the distal end of the one or more resistive filler wires is in contact with the workpiece at or near the applied high intensity energy. The electrical heating current for the one or more resistive filler wires is controlled based on whether the distal end of the one or more resistive filler wires is in contact with the work piece. The applied high-strength energy and the one or more resistive filler wires are moved in the same direction along the workpiece in a fixed relationship to each other. In still other exemplary embodiments, the systems and methods of the present invention are used in welding or bonding operations. The embodiments discussed above focused on the use of filler metals in overlay operations. However, aspects of the present invention can be used in welding and bonding applications where the workpieces are joined using a welding operation and filler metal. Although aimed at overlaying filler metal, the embodiments, systems and methods described above are similar to those used in welding operations, described in more detail below. Therefore, in the following discussions, it will be understood that the above discussions generally apply, unless stated otherwise. In addition, the following discussion may include references to FIGS. 1-5.

Welding / bonding operations are commonly known to join multiple workpieces together in a welding operation where filler metal is combined with at least a portion of the workpiece metal to form a joint. Because we want to increase production throughput in welding operations, there is a continuing need for faster welding operations that do not result in welds with substandard quality. There is also a need to provide systems that can be welded quickly under adverse environmental conditions, such as at remote job sites. As described below, exemplary embodiments of the present invention provide significant advantages over existing welding techniques. Such advantages include, but are not limited to, reduced total heat input resulting in low distortion of the workpiece, very high welding speed, very low spatter rate, welding without shielding, spatter It may include welding of plated or coated materials at high speed with little or no spatter and welding of complex materials at high speed.

In exemplary embodiments of the present invention, a very high welding speed, compared to arc welding, can be obtained using coated workpieces, which typically require significant preparation work and are much slower welding processes using arc welding methods. have. As an example, the following discussion will focus on welding galvanized workpieces. Galvanizing of metal is used to increase the corrosion resistance of the metal and is desirable in many industrial applications. However, welding of conventional galvanized workpieces can be problematic. Specifically, during welding, zinc of zinc plating is vaporized, and this zinc vapor can be trapped in the welding puddle as it solidifies in a weld puddle, thereby causing porosity. These pores negatively affect the strength of the weld joint. Because of this, existing welding techniques require the first step of removing the galvanizing or welding through the galvanizing at a lower processing speed and with some level of defects-which is inefficient and delays. Trigger, or require that the welding process proceed slowly. By slowing the process, the welding puddle remains molten for a longer period of time allowing the vaporized zinc to escape. However, due to the slow speed, the production speed may be slow and the total heat input to the weld may be high. Other coatings that can cause similar problems include, but are not limited to, paints, stamping lubricants, glass linings, aluminized coatings, surface heat treatment, nitriding or carbonization treatments. , Cladding treatments, or other vaporizing coatings or materials. As described below, exemplary embodiments of the present invention eliminate these problems.

Returning to FIGS. 6 and 6A (cross-section and side views, respectively), a representative welding lap joint is shown. In this figure, two coated (eg, galvanized) workpieces W1 / W2 will be joined together with a lap weld. The overlap joint surfaces 601 and 603 are initially covered with the surface 605 of the workpiece W1 as well as the coating. In a typical welding operation (eg GMAW), portions of the covered surface 605 are melted. This is due to the typical depth of penetration of standard welding operations. As the surface 605 melts, the coating on the surface 605 vaporizes, but because the distance of the surface 605 from the surface of the weld pool is large, gases are used to solidify the weld pool. You can get locked up as you become. Using the embodiments of the present invention, this does not occur.

6 and 6A, a laser beam 110 is directed from the laser device 120 to the weld joint, specifically the surfaces 601 and 603. The laser beam 110 is the energy density for melting the portions of the welding surfaces that produce the melting puddle 601A and 603A, which creates a typical welding puddle. In addition, the filler wire 140, which is resistance-heated as described above, is directed to the weld puddle to provide the necessary filler material for the weld bead. Unlike most welding processes, the filler wire 140 comes into contact with the welding puddle during the welding process. This is because this process does not use a welding arc to transmit the filler wire 140 and instead melts the filler wire into the welding puddle.

Since the filler wire 140 is preheated to or near its melting point, its presence in the welding puddle will not significantly cool or solidify the puddle and is quickly consumed into the welding puddle. The general operation and control of the filler wire 140 is as described above for the overlay embodiments.

Since the laser beam 110 can be precisely focused and aimed at the surfaces 601/603, the penetration depth for the pools 601A / 603A can be precisely controlled. By carefully controlling this depth, embodiments of the present invention prevent any unnecessary penetration or melting of the surface 605. Since the surface 605 does not melt excessively, no coating on the surface 605 is vaporized and is not trapped in the welding puddle. In addition, any coating on the surface of the welded joints 601 and 603 is easily vaporized by the laser beam 110 and the gas exits the weld zone before the weld puddle solidifies. It becomes possible. Gas extraction systems can be used to help remove any vaporized materials.

Since the depth of penetration of the welding puddle can be precisely controlled, the speed of welding the coated workpiece can be greatly increased while the pores are significantly minimized or eliminated. Some arc welding systems can achieve good running speeds for welding, but problems such as pores and spatters can occur at higher speeds. In exemplary embodiments of the present invention, a very high traveling speed can be achieved with little or no pores or spatters (as discussed herein), and in fact a traveling speed exceeding 50 inches / min. It can be achieved for many different types of welding operations. Embodiments of the present invention can achieve a welding progress rate exceeding 80 inches / min. In addition, as discussed herein, other embodiments may achieve a running speed in the range of 100 inches / min to 150 inches / min with minimal or no pores or spatter. Of course, the speeds achieved will be a function of the workpiece properties (thickness and composition) and wire properties (eg, diameter), but these speeds, when using embodiments of the invention, have many different welding and bonding applications. Is easily achievable. In addition, these rates can be achieved with 100% carbon dioxide shielding gas, or without any shielding. In addition, these speeds of progress can be achieved without removing any surface coating prior to creation and welding of the weld puddle. Of course, it can be considered that higher running speeds can be achieved. Furthermore, due to the reduced heat input to the weld, these high velocities are typically achieved for thinner workpieces 115, which have a slower weld speed because the heat input must be kept low to prevent distortion. Can be. Embodiments of the present invention can not only achieve the high travel speeds described above with little or no pores or spatters, but also low admixtures, and also very high deposition rates. Specifically, embodiments of the present invention can achieve a deposition rate of at least 10 lb / hr without shielding gas and with little or no pores or spatter. In some embodiments, the deposition rate ranges from 10 lb / hr to 20 lb / hr.

In exemplary embodiments of the present invention, these very high traveling speeds are achieved with little or no pores and little or no spatter. The porosity of the weld can be determined by examining the cross-section and / or length of the weld bead to identify the porosity ratio. The porosity of the cross-section is the total area of the porosity at a given cross-section of the total cross-sectional area of the weld joint at that point. The length porosity is the total accumulated length of pores in a unit length of a given weld joint. Embodiments of the present invention can achieve the speeds described above while having a cross-sectional porosity between 0% and 20%. Thus, weld beads without bubbles or cavities will have a porosity of 0%. In other exemplary embodiments, the cross-sectional porosity may range from 0% to 10%, and in other embodiments, from 2% to 5%. It will be appreciated that in some welding applications, a certain level of porosity is acceptable. In addition, in exemplary embodiments of the present invention, the porosity of the length of the weld is in the range of 0% to 20%, and may be 0% to 10%. In still other embodiments, the length porosity ranges from 1% to 5%. Thus, for example, welds having a cross-sectional porosity of 2% to 5% and a length porosity of 1% to 5% can be produced.

Furthermore, embodiments of the present invention can be welded at the identified traveling speeds with little or no spatter. Droplets are generated when droplets of the welding puddle are caused to splash out of the welding area. If a weld spatter occurs, it may deteriorate the quality of the weld and cause production delays, so it must typically be cleaned in the workpieces after the welding process. Therefore, there is a great advantage in welding at high speed without spatter. Embodiments of the invention can be welded at the high travel speeds with a spatter factor of 0 to 0.5, where the spatter factor is the consumed filler wire over a given travel distance (X). It is the weight of the spatter (in mg) over the same distance (X) of the weight of 140 (in Kg). In other words:

Spatter factor = (Spatter weight (mg) / consumed filler wire weight (kg))

The distance X should be a distance in consideration of representative sampling of the weld joint. That is, if the distance X is too short, for example, 0.5 inch, it may not represent the weld. Thus, a weld joint with a spatter factor of 0 will have no spatter for the consumed filler wire over the distance X, and a weld with a spatter factor of 2.5 has 2 Kg of consumed filler wire. About 5 mg of spatter. In an exemplary embodiment of the invention, the spatter factor ranges from 0 to 1. In another exemplary embodiment, the spatter factor ranges from 0 to 0.5. In another exemplary embodiment of the invention, the spatter factor ranges from 0 to 0.3. Embodiments of the present invention may achieve the sputter factor ranges described above with or without any external shielding, including shielding gas or otherwise flux shielding. Furthermore, the spatter factor ranges can be achieved when welding uncoated or coated workpieces, including galvanized workpieces-without removing the zinc plating prior to the welding operation.

There are many ways to measure spatter on a weld joint. One method may involve the use of a "spatter boat". For such a method, a representative weld sample is placed in a container of sufficient size to capture all or almost all of the spatter generated by the weld beads. Portions of the vessel or the vessel, such as the top, can be moved with the welding process to ensure that the spatter is captured. Typically, the boat is made of copper, so the spatter does not stick to the surfaces. The representative welding is performed above the bottom of the vessel such that any spatter generated during the welding falls into the vessel. During the welding, the amount of filler wire consumed is monitored. After the welding is completed, the spatter boat, if any, should be weighed by a device with sufficient accuracy to determine the difference between the pre-weld and post-weld weights of the vessel. This difference represents the weight of the spatter, which is then divided by the amount, in Kg, of the consumed filler wire. Alternatively, if the spatter does not stick to the boat, the spatter can be removed and weighed by itself.

As described above, the use of the laser device 120 enables precise control of the depth of the welding puddle. Furthermore, the use of the laser 120 makes it easy to adjust the size and depth of the welding puddle. This is because the laser beam 110 can be easily focused / defocused or very easily changes its beam intensity. Due to these abilities, the heat distribution on the workpieces W1 and W2 can be precisely controlled. This control not only makes it possible to create very narrow welding puddle for precise welding, but also minimizes the size of the welding area of the workpiece. This also provides an advantage in minimizing areas of the work piece that are not affected by the weld bead. Specifically, areas of the workpiece adjacent to the weld bead will be minimally affected by the welding operation, often not in the case of arc welding operations.

In exemplary embodiments of the present invention, the shape and / or strength of the beam 110 may be adjusted / changed during the welding process. For example, it may be necessary to change the depth of penetration or to change the size of the weld bead at certain locations on the workpiece. In such embodiments, the shape, strength, and / or size of the beam 110 can be adjusted during the welding process to provide the necessary changes in the welding parameters.

As described above, the filler wire 140 collides with the same welding puddle as the laser beam 110. In an exemplary embodiment, the filler wire 140 impinges the welding puddle at the same location as the laser beam 110. However, in other exemplary embodiments, the filler wire 140 may collide with the same welding puddle away from the laser beam. In the embodiment shown in FIG. 6A, the filler wire 140 tracks the beam 110 during the welding operation. However, it is not necessary as the filler wire 140 is located in the preceding position. As long as the filler wire 140 collides with the same welding puddle as the beam 110, the filler wire 140 may be positioned at different positions relative to the beam 110, so the present invention relates to this. Is not limited.

The embodiments described above have been described with respect to workpieces with coatings, such as zinc plating. However, embodiments of the present invention can also be used on workpieces without a coating. Specifically, the same welding process described above can be used with uncoated workpieces. Such embodiments achieve the same performance characteristics as described above for coated metals.

Further, exemplary embodiments of the present invention are not limited to steel workpieces, but can also be used to weld aluminum, or more complex metals, as will be described further below.

Another advantageous aspect of the invention relates to shielding gases. In a typical arc welding operation, a shielding gas or shielding flux is used to prevent oxygen and nitrogen, or other harmful elements in the atmosphere, from interacting with the welding puddle and metal transfer. Such interference can be detrimental to the quality and appearance of the weld. Therefore, in almost all arc welding processes, externally supplied shielding gas, granulation supplied externally or by consumption of an electrode having a flux thereon (e.g., stick electrode, flux cored electrode, etc.) Shielding is provided using a shielding gas produced by a granulated) flux (eg, sub-arc welding). Also, in some welding operations, such as welding of specialized metals or welding of galvanized workpieces, a special shielding gas mixture must be used. Such mixtures can be very expensive. Also, when welding in extreme environments, it is often difficult to transfer a large amount of shielding gas to the job site (as in pipelines), or wind is likely to blow the shielding gas out of the arc. In addition, the use of fume extraction systems has recently increased. While these systems are easy to remove fumes, they are also easy to draw out shielding gas when located close to the welding operation.

Advantages of the present invention include that the shielding gas may be used in a minimal amount or not at all when welding. Alternatively, embodiments of the present invention make it possible to use shielding gases that cannot normally be used for a particular welding operation. This is discussed further below.

When welding ordinary (uncoated) workpieces with an arc welding process, shielding-regardless of its shape-is required. It has been found that when welding with embodiments of the present invention, no shielding is required. That is, no shielding gas, no granular flux and no self-shielding electrodes need to be used. However, unlike in the arc welding process, the present invention produces a good quality weld. That is, the welding speeds described above can be achieved without using any shielding. This could not have been achieved in previous arc welding processes.

During a normal arc welding process, molten droplets of the filler wire are transmitted through the welding arc from the filler wire to the welding puddle. Without shielding, the entire surface of the droplet is exposed to the atmosphere during transmission and thus is easy to trap nitrogen and oxygen in the atmosphere and transfer the nitrogen and oxygen to the welding puddle. This is not desirable.

The present invention does not use droplets or similar processes, and since the filler wire is delivered to the weld, the filler wire is not exposed to the atmosphere as much. Therefore, in many welding applications, the use of shielding is not required. As such, embodiments of the present invention not only achieve high welding speeds with little or no pores or spatter, but can also do so without the use of shielding gas.

Without the use of shielding, it is possible to position the fume extraction nozzle much closer to the weld joint during welding, thus providing more efficient and effective fume extraction. If a shielding gas is used, it is necessary to position the fume extraction nozzle so that it does not interfere with the function of the shielding gas. Due to the advantages of the present invention, there is no such limitation and fume extraction can be optimized. For example, in an exemplary embodiment of the present invention, the laser beam 110 shields the beam from the laser 120 to near the surface of the workpiece 115, a laser shroud assembly, 1901 ). The representation of this can be seen in Figure 19. The shroud 1901 (shown in cross section) protects the beam 110 from interference and provides additional safety during operation. Furthermore, the shroud may be coupled to a fume extraction system 1902, which draws any welding fumes away from the welding area. Since embodiments can be used without any shielding gas, the shroud 1901 can be positioned very close to the weld to directly draw the fumes away from the weld zone. Indeed, the shroud 1901 may be positioned such that its distance Z above the weld is in the range of 0.125 inches to 0.5 inches. Of course, other distances may be used, but care must be taken not to disturb the welding puddle or to significantly degrade the effectiveness of the shroud 1901. Since fume extraction systems 1902 are generally understood and known in the welding industry, their construction and operation will not be discussed in detail herein. 19 shows that the shroud 1901 only protects the beam 110, the shroud 1901 is also configured such that it covers at least a portion of the wire 140 and the contact tip 160 Of course it is possible. For example, it is also possible that the bottom opening of the shroud 1901 is large enough to cover almost the entire welding puddle, or larger than the welding puddle, to increase fume extraction.

In exemplary embodiments of the invention used to weld coated workpieces, such as galvanized workpieces, a much less expensive shielding gas can be used. For example, 100% CO ₂ shielding gas can be used to weld many different materials, including mild steels. This also applies when welding more complex metals, such as stainless steel, duplex steel and super duplex steel, which can be welded with only 100% nitrogen shielding gas. In typical arc welding operations, stainless steel, duplex steel or super duplex steel welding requires a more complex shielding gas mixture, which can be very expensive. Embodiments of the invention allow these steels to be welded with only 100% nitrogen shielding gas. In addition, other embodiments allow these steels to be welded without any shielding. In a typical welding process for galvanized materials, a special mixed shielding gas, such as an argon / CO ₂ combination, must be used. During normal arc welding, since a cathode and an anode are present in the welding region, in part, this type of gas needs to be used. However, as described above and further described below, there is no welding arc, and thus, there is no anode or cathode in the welding region. Therefore, since there is no arc and no droplet transfer, the opportunity for the filler metal to pick up harmful elements from the atmosphere is greatly reduced. It should be noted that although many embodiments of the present invention allow welding without the use of shielding, such as shielding gas, it is possible to utilize gas flow over the weld to remove vapor or contaminants from the welding area. That is, it is contemplated that during welding, air, nitrogen, CO ₂ , or other gases can be blown over the weld to remove contaminants from the weld zone.

In addition to being able to weld high-speed coated materials, embodiments of the present invention can also be used to weld dual-phase steel with significantly reduced heat affected zone (HAZ). Can. The abnormally structured steel is a high-strength steel having a ferrite and martensitic microstructure, so that the steel can have high strength and good formability. Due to the nature of the abnormal tissue steels, the strength of the abnormal tissue steel welds is limited by the strength of the heat-affected zone. The heat-affected zone is an area around the weld joint (which does not contain the filler metal) that is significantly heated from the welding process such that its microstructure is negatively changed due to the arc welding process. In known arc welding processes, the thermal influence is very large, due to the size of the arc plasma and high heat input into the welding area. Since the heat-affected portion is very large, the heat-affected portion becomes a strength limiting portion of the weld. As such, since the use of high strength electrodes is unnecessary, arc welding processes typically use mild steel filler wires 140 to weld such joints (eg, ER70S-6, or -3 type electrodes). Furthermore, this requires designers to position welded joints in abnormally textured steels strategically away from high stress structures, such as in automobile frames, bumpers, engine cradles, and the like.

As mentioned above, the use of the laser device 12 provides a high degree of precision in the production of the welding puddle. Due to this precision, the heat affected portion surrounding the weld bead can be kept very small, or the overall effect of the heat affected portion on the workpiece can be minimized. Indeed, in some embodiments, the heat-affected portion of the workpiece can be virtually eliminated. This is achieved by keeping the focus of the laser beam 110 only on the parts of the work piece to be produced. By significantly reducing the size of the heat-affected zone, the strength of the base metal is not as bad as when the arc welding process is used. As such, the presence or location of the heat-affected portion is no longer a limiting factor in the design of a welded structure. Embodiments of the present invention make it possible to use higher strength filler wires, because instead of the heat-affected zone, the composition and strength of the workpiece and the strength of the filler wire can be driving factors in structural design. For example, embodiments of the present invention now enable the use of electrodes with at least 80 ksi yield strength, such as ER80S-D2 type electrodes. Of course, this electrode is intended to be illustrative. Furthermore, since the heat input from the arc welding is less then, the cooling rate of the puddle will be faster, which may weaken the chemistry of the filler wires used, but can provide more performance than the existing wires. have.

In addition, embodiments of the present invention can be used to weld titanium with significantly reduced shielding requirements. It is known that when welding titanium with an arc welding process, great care must be taken to ensure that an acceptable weld is created. This is because titanium has a strong affinity during the welding process and reacts with oxygen. The reaction between titanium and oxygen produces titanium dioxide, which, if present in the weld pool, can significantly reduce the strength and / or ductility of the weld joint. Because of this, when arc welding titanium, it is necessary to provide a very large amount of trailing shielding gas to shield the arc from the atmosphere as well as the trailing molten puddle as the puddle cools. Due to the heat generated from arc welding, the weld puddle can be very large and remain molten for a long time, thus requiring a significant amount of shielding gas. Embodiments of the invention significantly reduce the time the material melts and rapidly cools, reducing the need for this extra shielding gas.

As described above, the laser beam 110 can be focused very carefully to significantly reduce the overall heat input to the weld zone, thereby significantly reducing the size of the weld puddle. Because the weld puddle is smaller, the weld puddle cools much faster. In this way, not only the trailing shielding gas but also shielding is not required for the welding portion. In addition, for similar reasons discussed above, the welding speed is increased, but the spatter factor is greatly reduced when welding titanium.

Returning to FIGS. 7 and 7A, an open root type weld joint is shown. Open root joints are often used to weld thick plates and pipes and can often occur in remote and environmentally difficult locations. Shielded metal arc welding (SMAW), gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), flux cored arc welding, FCAW), submerged arc welding (SAW), and many known welding of open root joints, including self-shielded, flux cored arc welding (self shielded, FCAW-S) There are ways. These welding processes have a variety of disadvantages, including the need for shielding, speed limitations, the creation of slag, and the like.

Thus, embodiments of the present invention greatly improve the efficiency and speed at which these types of welding can be performed. Specifically, the use of shielding gas can be eliminated or greatly reduced, and the occurrence of slag can be completely eliminated. Furthermore, high-speed welding can be obtained with minimal spatter and pores.

7 and 7A show representative open root welded joints welded by exemplary embodiments of the present invention. Of course, embodiments of the present invention can be used to weld a wide variety of welded joints, not just overlapping or open rooted joints. In FIG. 7 a gap 705 is shown between the workpieces W1 / W2 and each workpiece has an angled surface 701/703. As described immediately above, embodiments of the present invention use a laser device 120 to create a precise melt puddle on the surfaces 701/703, a pre-heated filler wire (not shown), As described above, each is deposited into the puddle.

Indeed, exemplary embodiments of the present invention are not limited to aiming a single filler wire with each welding puddle. Since the welding arc is not generated in the welding process described in the present invention, more than one filler wire can be aimed at either welding puddle. By increasing the number of filler wires for a given welding puddle, the overall deposition rate of the welding process can be significantly increased without a significant increase in heat input. Thus, it is conceivable that development root weld joints (such as the type shown in FIGS. 7 and 7A) can be filled with a single weld pass.

Also, as shown in FIG. 7, in some exemplary embodiments of the present invention, multiple laser beams 110 and 110A may be used to melt more than one location at the same time at the weld joint. This can be accomplished in many ways. In the first embodiment, shown in FIG. 7, a beam splitter 121 is used and coupled to the laser device 120. The beam splitter 121 is known to those skilled in the art of laser devices and need not be discussed in detail herein. The beam splitter 121 may split the beam from the laser device 120 into two (or two or more) separate beams 110 / 110A and direct them to two different surfaces. In such an embodiment, multiple surfaces can be irradiated simultaneously, providing better precision and accuracy in welding. In another embodiment, the separate beams 110 and 110A can each be generated by a separate laser device, so that each beam is emitted from its own dedicated device.

In such an embodiment, using multiple laser devices, many aspects of the welding operation can be varied to suit different welding needs. For example, the beams generated by the separate laser devices can have different energy densities; The weld joint may have different shapes and / or different cross-sectional areas. With this flexibility, aspects of the welding process can be modified and customized to meet any specific welding parameters required. Of course, this may be achieved with the use of a single laser device and beam splitter 121, but some of the flexibility may be limited with the use of the single laser source. In addition, since it can be thought that lasers can be used as many as desired, the present invention is not limited to single or dual laser configurations.

In still other exemplary embodiments, a beam scanning device can be used. Such devices are well known in the art of laser or beam emission and are used to scan the beam 110 with a pattern on the surface of the workpiece. With such devices, scan speed and pattern as well as dwell time can be used to heat the workpiece 115 in a desired manner. In addition, the output power of the energy source (eg, laser) can be adjusted as desired to produce the desired puddle formation. In addition, the optical system used in the laser 120 can be optimized based on desired job and junction parameters. For example, line and integrator optics can be widely used to generate focused line beams for welding or cladding operations, or the integrators produce square / rectangular beams with uniform power distribution. Can be used to

7A shows another embodiment of the present invention, where a single beam 110 is aimed at the open root junction to melt the surfaces 701/703.

Due to the precision of the laser beams 110 and 110A, the beams 110 / 110A can be focused away from the gap 705 and only over the surfaces 701/703. Because of this, melt-through (usually falling through the gap 705) can be controlled, which greatly improves control of the back welding bead (welding beads on the bottom surface of the gap 705). .

In each of FIGS. 7 and 7A, a gap 705 is present between the workpieces W1 and W2, which are filled with welding beads 707. In an exemplary embodiment, this weld bead 705 is produced by a laser device (not shown). Thus, for example, during a welding operation, a first laser device (not shown) may gap the first laser beam (not shown) to weld the workpieces W1 and W2 with the laser welding bead 707. 705, while the second laser device 120 has at least one laser beam 110 / 110A to create welding puddle where filler wire (s) (not shown) are deposited to complete welding. ) To the surfaces 701/703. The gap welding bead 707 can be produced by laser only if the gap is small enough, or by using laser and filler wire if the gap 705 so requires. Specifically, it may be necessary to add filler metal to properly fill the gap 705, so a filler wire must be used. The creation of this gap bead 705 is similar to that described above in connection with various exemplary embodiments of the present invention.

It should be noted that high intensity energy sources, such as the laser devices 120 discussed herein, should be of a type having sufficient power to provide the energy density required for the desired welding operation. That is, the laser device 120 must have sufficient power to create and maintain a stable welding puddle throughout the welding process, and must also reach a desired weld penetration. For example, for some applications, lasers should have the ability to "keyhole" the workpieces being welded. This means that the laser must have sufficient power to completely penetrate the workpiece, and at the same time maintain the level of penetration as the laser progresses along the workpiece. Preferred lasers should have a power capability in the range of 1 kW to 20 kW, and may have a power capability in the range of 5 kW to 20 kW. Higher power lasers can be used, but can be very expensive. Of course, the beam splitter 121 and multiple lasers can also be used for other types of welding joints, and can be used for lap joints, such as those shown in FIGS. 6 and 6A. Be careful.

7B shows another exemplary embodiment of the present invention. In this embodiment, a narrow groove, deep open root junction is shown. When arc welding deep junctions (with a depth greater than 1 inch), it may be difficult to weld the bottom of the junction when the gap G to the groove is narrow. This is because it is difficult to effectively deliver the shielding gas to such a deep groove, and the narrow walls of the groove can cause stability and interference of the welding arc. Since the workpiece is typically a ferrous material, the walls of the joint can magnetically and interfere with the welding arc. For this reason, when using conventional arc welding procedures, the gap G of the groove needs to be wide enough to allow the arc to remain stable. However, the wider the grooves, the more filler metal is needed to complete the welding. Since the embodiments of the invention do not require shielding gas and do not use a welding arc, these problems are minimized. This allows embodiments of the invention to weld deep, narrow grooves efficiently and effectively. For example, in the exemplary embodiment of the present invention, wherein the work piece 115 has a thickness exceeding 1 inch, the gap width G is 1.5 to 2 times the diameter of the filler wire 140 Range, and the sidewall angle ranges from 0.5 degrees to 10 degrees. In an exemplary embodiment, the root pass preparation of such a weld joint has a gap RG ranging from 1 mm to 3 mm with lands ranging from 1/16 inch to 1/4 inch. Thus, deep open root joints can be welded faster and with much less filler metal than ordinary arc welding processes. In addition, since aspects of the present invention introduce much less heat into the weld zone, the tip 160 can be designed to facilitate being transferred much closer to the weld puddle to prevent contact with the sidewall. have. That is, the tip 160 can be made smaller and can be configured as an insulated guide with a narrow structure. In another exemplary embodiment, a translation device or mechanism can be used to move the laser and wire across the width of the weld to simultaneously weld both sides of the joint.

8, a butt-type joint can be welded to embodiments of the present invention. In Figure 8, a flush butt joint is shown, but it is conceivable that butt joints with v-notched grooves on the top and bottom surfaces of the weld joint can also be welded. In the embodiment shown in Figure 8, two laser devices 120 and 120a are shown on both sides of the weld joint, each creating its own welding puddle 801 and 803. 7 and 7A, heated filler wires are not shown, as they are trailing behind the laser beams 110 / 110A in the illustrated figure.

When welding butt-type welds with known arc technology, considerable "arc blow" occurs when the magnetic fields generated by the welding arcs interfere with each other and cause the arcs to move abnormally. There may be a problem. In addition, when two or more arc welding systems are being used to weld on the same weld joint, there can be significant problems due to interference of the respective welding currents. In addition, due to the depth of penetration of arc welding methods, in part, due to the high heat input, the thicknesses of workpieces that can be welded with arcs on both sides of the weld joint are limited. That is, such welding cannot be performed on thin work pieces.

When welding with embodiments of the present invention, these problems are eliminated. Since there is no welding arc used, there are no arc blow interference or welding current interference problems. In addition, due to the precise control of heat input and penetration depth, which is possible through the use of lasers, much thinner workpieces can be welded simultaneously on both sides of the weld joint.

Another exemplary embodiment of the present invention is shown in FIG. 9. In this embodiment, two laser beams 110 and 110A are used-side by side-to create a unique welding profile. In the illustrated embodiment, the first laser beam 110 (emitted from the first laser device 120) is used to create a first portion of the welding puddle 901 having a first cross-sectional area and depth, while The second laser beam 110A (emitted from the second laser device (not shown)) is used to create a second portion of the welding puddle 903 having a second cross-sectional area and depth, different from the first one. . This embodiment can be used where it is desired that a portion of the weld bead has a deeper penetration depth than the rest of the weld bead. For example, as shown in FIG. 9, the puddle 901 is made deeper and narrower than the welding puddle 903, which is made wider and shallower. Such an embodiment may be used where a deep penetration depth is required where the workpieces meet but is not desired for all parts of the weld joint.

In another exemplary embodiment of the present invention, the first puddle 903 may be a welding puddle that creates a weld to the junction. This first puddle / junction is created using the first laser 120 and filler wire (not shown), and is made to an appropriate penetration depth. After this weld joint is made, a second laser (not shown) emitting a second laser beam 110A passes over the joint to create a second puddle 903 with a different profile, where this second fur They are used to deposit certain types of overlays, as described in conjunction with the above embodiments. This overlay will be deposited using a second filler wire having a different chemistry than the first filler wire. For example, embodiments of the present invention may be used to place a corrosion-resistant cladding layer over the welded joint immediately or immediately after the joint is welded. This welding operation can also be accomplished with a single laser device 120 in which the beam 110 oscillates between a first beam shape / density and a second beam shape / density to provide the desired welding puddle profile. . Thus, multiple laser devices need not be used.

As described above, a corrosion resistant coating on the workpieces (such as zinc plating) is removed during the welding process. However, since it may be desirable for the weld joint to be coated again for corrosion resistance purposes, the second beam 110A and the laser add a corrosion resistant overlay 903, such as a cladding layer, over the top of the joint 901. Can be used to

Due to the various advantages of the present invention, it is also possible to easily bond dissimilar metals through a welding operation. It is difficult to bond dissimilar metals using an arc welding process, as the required chemical properties for dissimilar metals and filler materials can lead to cracking and inferior welds. This is especially true when they attempt to arc weld aluminum and steel to each other, with very different melting temperatures, or even to weld stainless steels to mild steel, because of their different chemical properties. However, with the embodiments of the present invention, such problems are alleviated.

10 shows an exemplary embodiment of the present invention. Although a V-shaped junction is shown, the invention is not limited in this regard. In FIG. 10, two dissimilar metals are shown being joined at the weld joint 1000. In this example, the two dissimilar metals are aluminum and steel. In this exemplary embodiment, two different laser sources 1010 and 1020 are used. However, since a single device can be vibrated to supply the energy needed to melt the two different materials-which will be discussed further below-two laser devices are not required in all embodiments. The laser 1010 emits the beam 1011 aimed at the steel workpiece, and the laser 1020 emits the beam 1021 to the aluminum workpiece. Since each of the above workpieces are made of different metals or alloys, they have different melting temperatures. As such, each of the laser beams 1011/1021 has a different energy density in the welding puddle 1012 and 1022. Due to the different energy densities, each of the welding puddle 1012 and 1022 can be maintained at an appropriate size and depth. It also prevents excessive penetration and heat input in workpieces with lower melting temperatures-for example, aluminum. In some embodiments, at least due to the weld joint, there is no need to have two separate, separate welding puddle (as shown in FIG. 10), rather a single welding puddle can be formed with the two workpieces, , Where the molten parts of the respective workpieces form a single welding puddle. It is also understood that if the workpieces have different chemical properties but have similar melting temperatures, it is possible to use a single beam to irradiate both workpieces simultaneously, and one workpiece will melt more than the other. Will be able to. It is also possible to use a single energy source (such as laser device 120) to irradiate two workpieces, as briefly described above. For example, laser device 120 uses a first beam shape and / or energy density to melt the first workpiece and then a second beam shape and / or energy density to melt the second workpiece. It can be vibrated / changed. Vibration and alteration of the beam properties must be performed at a sufficient rate to ensure proper melting of the two workpieces is maintained so that the welding puddle (s) remain stable and consistent during the welding process. Other single beam embodiments may utilize a beam 110 in a form that provides more heat input than the other in one work piece to ensure sufficient melting of each work piece. In such embodiments, the energy density of the beam may be uniform with respect to the cross section of the beam. For example, the beam 110 may have a parallelogram or triangular shape, and accordingly, due to the shape of the beam, the total heat input to one work piece will be less than the other. Alternatively, some embodiments may use a beam 110 having a non-uniform energy distribution in its cross section. For example, the beam 110 may have a rectangular shape (so that it strikes two workpieces), but the first area of the beam will have a first energy density and the second area of the beam 110. Will have a second energy density that is different from the first region, so each of the regions can melt each work piece properly. As an example, the beam 110 may have a first region with a high energy density to melt the steel workpiece, while the second region will have a lower energy density to melt the aluminum workpiece. will be.

In Fig. 10, two filler wires 1030 and 1030A are shown and aimed at welding puddle 1012 and 1022, respectively. Although the embodiment shown in FIG. 10 uses two filler wires, the present invention is not limited in this regard. As discussed above in relation to other embodiments, depending on the desired welding parameters, such as desired bead shape and deposition rate, only one filler wire can be used or more than two wires can be used. Can think. If a single wire is used, it can be directed to a common puddle (formed from the molten parts of the two workpieces), or the wire is only one of the molten parts for integration into the weld joint. Can be directed. Thus, for example, in the embodiment shown in FIG. 10, wire can be directed to the molten portion 1022 to be subsequently joined with the molten portion 1012 for formation of the weld joint. Of course, if a single wire is used, the wire must be heated to a temperature that allows the wire to melt in the portion 1022/1012 where it is immersed.

Since dissimilar metals are being bonded, the chemical properties of the filler wires should be chosen to ensure that the wires can be sufficiently adhered to the metals to which they are being bonded. Furthermore, the composition of the filler wire (s) should be selected to have a suitable melting temperature, which allows it to melt and be consumed in the lower temperature welding puddle. In fact, it is contemplated that the chemical properties of multiple filler wires may be different to achieve proper welding chemical properties. This is especially the case when the two different workpieces have material compositions, with minimal admixture between the materials. In FIG. 10, the lower temperature welding puddle is an aluminum welding puddle 1012, such that the filler wire (s) 1030 (a) are made to melt at a similar temperature, thus they are ) Can be easily consumed. In the above example, using aluminum and steel workpieces, the filler wires have a melting temperature similar to the melting temperature of the workpiece, silicon bronze, nickel aluminum bronze, or aluminum bronze. bronze) -based wire. Of course, the filler wire compositions should be selected to match the desired mechanical and welding performance properties, but it is contemplated that at the same time it should provide melting properties similar to the melting properties of at least one of the workpieces to be welded.

11A-11C show various embodiments of the tip 160 that can be used. 11A shows a tip 160 that is very similar in construction to an ordinary arc welding contact tip. During hot wire welding as described herein, heating current is directed from the power supply 170 to the contact tip 160 and passed from the tip 160 into the wire 140. The current is then directed to the workpiece through the wire and to the workpiece W through contact of the wire 140. This current flow, as described herein, heats the wire 140. Of course, the power supply 170 may not be directly coupled to the contact tip, as shown, but may be coupled to a wire supply 150 that directs the current to the tip 160. 11B shows another embodiment of the present invention, wherein the tip 160 is composed of two components 160 and 160 ', whereby the negative terminal of the power supply 170 is the first It is coupled to two components 160 '. In such an embodiment, the heating current flows from the first tip component 160 to the wire 140 and then to the second tip component 160 '. The flow of current through the wire 140 between the components 160 and 160 'allows the wire to be heated, as described herein. FIG. 11C shows another exemplary embodiment including an induction coil 1110, such that the tip 160 allows the tip 160 and the wire 140 to be heated through induction heating. have. In such an embodiment, the induction coil 1110 can be made integral with the contact tip 160 or can be wound around the surface of the tip 160. Of course, other configurations may be used for the tip 160 so long as the tip delivers the required heating current / power to the wire 140 so that the wire can achieve the desired temperature for the welding operation.

The operation of exemplary embodiments of the present invention will be described. As noted above, embodiments of the invention use both a high intensity energy source and a power supply to heat the filler wire. Each aspect of this process will be discussed in turn. It should be noted that the following descriptions and discussions are not intended to replace or replace any of the discussions provided above in connection with the overlay embodiments discussed above, but to supplement those discussions in connection with welding or joining applications. will be. The previous discussions of overlay operations are also included for the purposes of bonding and welding.

Exemplary embodiments for bonding / welding may be similar to those shown in FIG. 1. As described above, a hot wire power supply 170 is provided that provides heating current to the filler wire 140. The current passes from the contact tip 160 (which may be of any known configuration) to the wire 140 and then into the workpiece. This resistance heating current causes the wire 140 between the tip 160 and the workpiece to reach a melting temperature or a temperature close to that of the filler wire 140 being used. Of course, the melting temperature of the filler wire 140 will depend on the size and chemical properties of the wire 140. Therefore, the desired temperature of the filler wire during welding will depend on the wire 140. As will be discussed further below, the desired working temperature for the filler wire may be data input to the welding system such that the desired wire temperature is maintained during welding. In any case, the temperature of the wire should allow the wire to be consumed into the welding puddle during the welding operation. In exemplary embodiments, at least a portion of the filler wire 140 solidifies as the wire enters the welding puddle. For example, at least 30% of the filler wire solidifies as the filler wire enters the welding puddle.

In an exemplary embodiment of the invention, the hot wire power supply 170 supplies a current that maintains at least a portion of the filler wire at a temperature above 75% of its melting temperature. For example, when using mild steel filler wire 140, the temperature of the wire before the wire enters the puddle may be about 1,600 ° F, while the wire has a melting temperature of about 2,000 ° F. Of course, the respective melting temperatures and desired working temperatures will depend at least on the alloy, composition, diameter and feed rate of the filler wire. In another exemplary embodiment, the power supply 170 maintains a portion of the filler wire at a temperature above 90% of its melting temperature. In still other exemplary embodiments, portions of the wire are maintained at a temperature of the wire that is at least 95% of its melting temperature. In exemplary embodiments, the wire 140 will have a temperature gradient from the point where the heating current is applied to the wire 140 and the puddle, where the temperature in the puddle is the heating current Is higher than the temperature at the input point of It is preferred that the wire 140 has the hottest temperature of the wire 140 at or near the point where the wire enters the puddle to facilitate efficient melting. Therefore, the temperature percentages mentioned above should be measured for the wire at or near the point where the wires enter the puddle. By maintaining the filler wire 140 at or near its melting temperature, the wire 140 is easily melted or consumed into the welding puddle generated by the heat source / laser 120. That is, the wire 140 has a temperature that does not result in significantly quenching the welding puddle when the wire 140 contacts the puddle. Due to the high temperature of the wire 140, the wire melts quickly when it contacts the welding puddle. It is desirable to have the wire temperature so that the wire does not hit the floor in the welding pool-so as not to contact the unmelted portion of the welding pool. Such contact can negatively affect the quality of the weld.

As previously described, in some exemplary embodiments, complete melting of the wire 140 may be facilitated only by entry of the wire 140 into the puddle. However, in other exemplary embodiments, the wire 140 may be completely melted by a combination of the puddle and the laser beam 110 impinging on a portion of the wire 140. In still other embodiments of the present invention, heating / melting of the wire 140 may be assisted by the laser beam 110 such that the beam 110 contributes to heating of the wire 140. have. However, since many filler wires 140 are made of materials that may be reflective, when a reflective laser type is used, the wire 140 is reduced in its surface reflectivity to reduce the beam 110 ) Must be heated to a temperature that can contribute to the heating / melting of the wire 140. In example embodiments of this configuration, the wire 140 and beam 110 intersect at the point where the wire 140 enters the puddle.

In addition, as discussed above with respect to FIG. 1, the power supply 170 and the controller 195 are configured such that the wire 140 maintains contact with the workpiece during welding and does not arc. The heating current to the wire 140 is controlled. Contrary to arc welding technology, the presence of an arc can lead to significant welding defects when molten with embodiments of the present invention. Thus, in some embodiments (such as those discussed above), the voltage between the wire 140 and the welding puddle indicates that the wire is shorted or in contact with the workpiece / weld puddle. , Should remain at 0 volts or near it.

However, in other exemplary embodiments of the present invention, it is possible to provide current at such a level that a voltage level exceeding 0 volts is achieved without arcing. By using higher current values, it is possible to maintain the electrode 140 at a level higher than or near the melting temperature of the electrode. This allows the welding process to proceed faster. In exemplary embodiments of the present invention, the power supply 170 monitors the voltage and the power supply 170 as the voltage reaches or approaches a voltage value at any point exceeding 0 volts. ) Stops flowing current through the wire 140 to ensure that no arc occurs. The voltage threshold level will typically, at least in part, depend on the type of welding electrode 140 used. For example, in some exemplary embodiments of the invention, the threshold voltage level is 6 volts or less. In another exemplary embodiment P, the threshold level is 9 volts or less. In another exemplary embodiment, the threshold level is 14 volts or less, and in a further exemplary embodiment, the threshold level is 16 volts or less. For example, when using mild steel filler wires, the threshold level for voltage will be of a lower type, while filler wires for stainless steel can handle higher voltages before arcing is generated.

In still other exemplary embodiments, as above, instead of keeping the voltage level below a threshold, the voltage is maintained in the working range. In such an embodiment, maintaining the voltage above a minimum amount is sufficient to keep the filler wire at or near its melting temperature, but below a voltage level that prevents a welding arc from being created. desirable. For example, the voltage can be maintained in the range of 1 volt to 16 volts. In another exemplary embodiment, the voltage is maintained in the range of 6 volts to 9 volts. In another example, the voltage can be maintained between 12 volts and 16 volts. Of course, the desired working range may be influenced by the filler wire 140 used in the welding operation, and accordingly, the range (or threshold) used in the welding operation is, at least in part, the used filler wire or Based on the properties of the filler wire used above, it is selected. In using such a range, the lower end of the range is set to a voltage at which the filler wire can be sufficiently consumed in the welding puddle, and the upper limit of the range is set to a voltage that prevents arc generation.

As described above, as the voltage exceeds a desired threshold, the heating current is cut off by the power supply 170 so that no arc is generated. This aspect of the invention will be discussed further below.

In many of the embodiments described above, the power supply 170 includes circuitry used to monitor and maintain the voltage, as described above. The construction of such a type of circuit is known to those skilled in the art to which this invention pertains. However, such circuits have traditionally been used for arc welding to keep the voltage above a certain threshold.

In still other exemplary embodiments, the heating current can also be monitored and / or regulated by the power supply 170. This can be done in addition to monitoring any level of voltage, power, or alternatively voltage / ampere characteristics. That is, the current can be maintained at a desired level or levels that ensure the wire 140 is maintained at an appropriate temperature-for proper consumption in the welding puddle, but still below the arcing current level. For example, in such an embodiment, the voltage and / or the current are monitored to ensure that either or both are within a certain range or below a desired threshold. The power supply then regulates the current supplied to ensure that no arc is generated but desired working parameters are maintained.

In another exemplary embodiment of the invention, the heating power (V × I) can also be monitored and regulated by the power supply 170. Specifically, in such embodiments, the voltage and current for the heating power are monitored to be maintained at a desired level or desired range. Thus, the power supply can adjust not only the voltage or current for the wire, but also both the current and the voltage. Such an embodiment can provide improved control over the welding device. In such embodiments, the heating power for the wire is set to an upper threshold or an optimal working range (similar to that discussed above with respect to the voltage) to ensure that the power remains below the threshold level or within a desired range. Can be. In other words, the threshold or range settings will be based on the characteristics of the filler wire and the welding performed, and at least in part, on the selected filler wire. For example, the optimum power setting for a mild steel electrode with a diameter of 0.045 "may be determined to range from 1950 watts to 2,050 watts. The power supply will adjust the voltage and current so that the power remains within this working range. Similarly, when the power threshold is set to 2,000 watts, the power supply will adjust the voltage and current so that the power level does not exceed this threshold but is close to this threshold.

In another exemplary embodiment of the present invention, the power supply 170 monitors the rate of change of the heating voltage (dv / dt), the rate of change of the current (di / dt), and the rate of change of the power (dp / dt). Circuits. Such circuits are often called prediction circuits, and their general construction is known. In such embodiments, the rate of change of the voltage, current and / or power is monitored such that the heating current to the wire 140 is turned off when the rate of change exceeds a certain threshold.

In an exemplary embodiment of the invention, the change in resistance (dr / dt) is also monitored. In such an embodiment, the resistance of the wire between the contact tip and the puddle is monitored. During welding, as the wire heats up, it begins to neck down and tends to form an arc, during which the resistance of the wire increases exponentially. When this increase is detected, the output of the power supply is turned off, as described herein, to ensure that no arc is generated. Embodiments regulate the voltage, current, or both, to ensure that the resistance of the wire is maintained at the desired level.

 In still other exemplary embodiments of the present invention, instead of blocking the heating current when the threshold level is detected, the power supply 170 may reduce the heating current to an arc non-occurring level. Such a level may be a background current level at which no arc will occur if the wire is separated from the welding puddle. For example, an exemplary embodiment of the present invention can have an arc non-occurring current level of 50 amperes, where once the arc occurrence is detected or predicted, or reaches the upper threshold (discussed above), The power supply 170 is for a predetermined amount of time (eg, 1 ms to 10 ms) or until the detected voltage, current, power, and / or resistance falls below the upper threshold. , Drop the heating current from its working level to the arc-free level. The arc non-occurrence threshold can be a voltage level, a current level, a resistance level, and / or a power level. In such embodiments, by maintaining a current output during an arcing event-albeit at a low level-it can cause it to return to the heating current working level faster.

In another exemplary embodiment of the present invention, the output of the power supply 170 is controlled such that substantially no arc is generated during the welding operation. In some example welding operations, the power supply may be controlled such that substantially no arc is generated between the filler wire 140 and the puddle. It is generally known that an arc is created between the distal end of the filler wire 140 and the physical contact gap between the weld puddle. As noted above, exemplary embodiments of the present invention prevent this arc from being created by the filler wire 140 maintaining contact with the puddle. However, in some exemplary embodiments, the presence of a substantive arc will not deteriorate the quality of the joint. That is, in some example welding operations, the creation of a short, non-substantial arc will not result in a level of heat input that will degrade the weld quality. In such embodiments, the welding system and power supply are controlled and operated as described herein in connection with completely preventing arcing, but the power supply 170 is capable of generating the arc to the extent that the arc is generated. It is controlled not to be practical. In some example embodiments, the power supply 170 is operated such that the generated arc has a duration of less than 10 ms. In other exemplary embodiments, the arc has a duration of less than 1 ms, and in other exemplary embodiments, the arc has a duration of less than 300 ms. In such embodiments, the presence of such arcs does not degrade the weld quality because the arc does not impart substantial heat input to the weld or cause significant spatter or pores. Thus, in such embodiments, the power supply 170 is controlled such that it remains indefinite in duration to the extent that an arc is generated so that the quality of the weld does not deteriorate. The same control logic and components as discussed herein in relation to other embodiments can be used in these example embodiments. However, for the upper threshold, the power supply 170 detects the generation of an arc instead of a threshold point (of current, power, voltage, resistance) below a predetermined or predicted arc generation point. Can be used. Such an embodiment can allow the welding operation to operate close to its limits.

Since the filler wire 140 is preferably in a continuously shorted state (in a state of being in constant contact with the welding puddle), the current tends to attenuate at a slow rate. This is due to the inductance present in the power supply, welding cables and work piece. In some applications, the current may need to be attenuated at a faster rate so that the current in the wire is reduced at high speed. In general, the faster the current can be reduced, the better control over the bonding method will be achieved. In an exemplary embodiment of the present invention, the ramp down time for the current is 1 millisecond after detection of an reached or exceeded threshold. In another exemplary embodiment of the present invention, the ramp down time for the current is 300 microseconds or less. In another exemplary embodiment, the ramp down time ranges from 300 microseconds to 100 microseconds.

In an exemplary embodiment, to achieve such ramp down times, a ramp down circuit is introduced into the power supply 170 that helps to reduce the ramp down time when an arc is predicted or detected. For example, if an arc is detected or otherwise predicted, the ramp down circuit is opened, which introduces resistance into the circuit. For example, the resistance may be of a type that reduces the flow of current to less than 50 amperes in 50 microseconds. A simplified example of such a circuit is shown in FIG. 18. The circuit 1800 has the resistor 1801 and the switch 1803 disposed in the welding circuit so that the switch 1803 closes when the power supply is operating and supplying current. However, when the power supply stops supplying power (to prevent the generation of arcs or when an arc is detected), the switch is opened to generate induced current through the resistor 1801. Force. The resistor 1801 greatly increases the resistance of the circuit and rapidly decreases the current. Such circuit types are commonly known in the welding industry, and Power Wave® welding manufactured by Lincoln Electric Company of Cleveland, Ohio, with surface-tension-transfer technology (STT). It can be found in the power supply. STT technology is generally described in U.S. Patent Nos. 4,866,247, 5,148,001, 6,051,810 and 7,109,439, all of which are incorporated herein by reference. Of course, these patents generally discuss using the disclosed circuitry to ensure that the arc is created and maintained-those skilled in the art to which the present invention pertains can easily adjust such a system to ensure that the arc is not generated. .

The above discussion can be further understood with reference to FIG. 12 where an exemplary welding system is shown (note that the laser system is not shown for clarity). The system 1200 is shown as having a hot wire power supply 1210 (which may be of a type similar to that shown as 170 in FIG. 1). The power supply 1210 may be a known welding power supply configuration, such as an inverter-type power supply. The design, operation and configuration of such power supplies are well known, so they will not be discussed in detail herein. The power supply 1210 allows the user to input data, including, without limitation, wire supply speed, wire type, wire diameter, desired power level, desired wire temperature, voltage and / or current level. It includes a user input device (user input, 1220). Of course, other input parameters can be used as needed. The user input device 1220 is coupled to a CPU / controller 1230, which receives this user input data and uses this information to generate necessary job set points or ranges for the power module 1250. The power module 1250 may be of any known type or configuration, including inverter-type or transformer-type modules.

The CPU / controller 1230 can determine the desired job parameters in any number of ways, including using a lookup table. In such an embodiment, the CPU / controller 1230 uses the input data, e.g., wire feed rate, wire diameter, and wire type, to achieve the desired output for output (to properly heat the wire 140). Determine the current level and threshold voltage or power level (or acceptable voltage or working range of power). This is because the current required to heat the wire 140 to an appropriate temperature will be based at least on the input parameters. That is, the aluminum wire 140 may have a lower melting temperature than the mild steel electrode, and thus requires less current / power to melt the wire 140. Also, the smaller diameter wire 140 will require less current / power than the larger direct electrode. In addition, as the wire speed increases (and thus the deposition rate increases), the current / power level required to melt the wire will be higher.

Similarly, the input data may be generated by the CPU / controller to determine voltage / power thresholds and / or ranges (e.g., power, current, and / or voltage) for the task to prevent arcing. 1230). For example, a mild steel electrode with a diameter of 0.045 inches can have a voltage range setting of 6 volts to 9 volts, where the power module 1250 is driven to maintain the voltage between 6 volts and 9 volts. In such an embodiment, the current, voltage, and / or power is driven to maintain a minimum value of 6 volts-ensuring that the current / power is high enough to properly heat the electrode, so that no arc is generated and The voltage is maintained at 9 volts or less to ensure that the melting temperature of the wire 140 is not exceeded. Of course, other setpoint parameters, such as voltage, current, power, or resistance changes, can also be set by the CPU / controller 1230 as desired.

As shown, the positive terminal 1221 of the power supply 1210 is coupled to the contact tip 160 of the hot wire system, and the negative terminal of the power supply is coupled to the workpiece W do. Therefore, the heating current is supplied to the wire 140 through the positive terminal 1221 and returns through the negative terminal 1222. Such configurations are generally known.

Of course, in other exemplary embodiments, the negative terminal 1222 may also be connected to the tip 160. Since resistive heating can be used to heat the wire 140, the tip is used for both the cathode and anode terminals 1221/1222 (as shown in FIG. 11) to heat the wire 140. It may be a configuration that can be coupled to the contact tip 140. For example, the contact tip 160 may have a dual configuration (as shown in FIG. 11B) or use an induction coil (as shown in FIG. 11C).

A feedback sense lead 1223 is also coupled to the power supply 1210. The feedback sensing lead may monitor the voltage and transfer the detected voltage to the voltage detection circuit 1240. The voltage detection circuit 1240 communicates the detected voltage and / or the detected rate of voltage change to the CPU / controller 1230, thereby controlling the operation of the module 1250. For example, if the detected voltage is less than the desired working range, the CPU / controller 1230 will display the output of the module (1250) until the detected voltage is within the desired working range. Voltage, and / or power). Similarly, if the detected voltage is above a desired threshold, the CPU / controller 1230 instructs the module 1250 to block the flow of current to the tip 160 so that no arc is generated. . If the voltage falls below the desired threshold, the CPU / controller 1230 instructs the module 1250 to supply current or voltage, or both, to continue the welding process. Of course, the CPU / controller 1230 may also instruct the module 1250 to maintain or supply a desired power level.

It should be noted that the detection circuit 1240 and the CPU / controller 1230 may have a similar configuration and operation to the controller 195 shown in FIG. 1. In exemplary embodiments of the present invention, the sampling / detection rate is at least 10 KHz. In other exemplary embodiments, the detection / sampling rate ranges from 100 KHz to 200 KHz.

13A-13C illustrate exemplary current and voltage waveforms used in embodiments of the present invention. Each of these waveforms will be discussed in turn. FIG. 13A shows voltage and current waveforms for an embodiment in which the filler wire 140 touches the welding puddle after the arc detection event-the power supply output is turned back on. As shown, the output voltage of the power supply was at some working level below the determined threshold (9 volts) and then increased to this threshold during welding. The working level can be a level determined based on various input parameters (discussed above) and can be a set working voltage, current, and / or power level. This work level is the desired output of the power supply 170 for a given welding operation and will provide the desired heating signal to the filler wire 140. During welding, events may occur that result in the creation of arcs. In FIG. 13A, the event triggers an increase in the voltage, causing it to increase to point A. At point A, the power supply / control circuit reaches the 9 volt threshold (which may be below the arc generation point, which may be an arc detection point or simply a predetermined upper threshold) and the current and voltage are at point B Turn off the output of the power supply to drop to a reduced level at). The slope of the current drop can be controlled by including a ramp down circuit (as discussed herein) that helps to rapidly reduce the current resulting from the system inductance. The current or voltage levels at point B can be predetermined or they can be reached after a predetermined duration. For example, in some embodiments, not only the upper threshold for voltage (or current or power) is set for welding, but also the lower arc non-occurrence level can be set. This lower level can be a lower voltage, current, or power level, where it is permissible to turn the power supply back on and ensure that no arc can be generated so that no arc is generated. Having such a lower level makes it possible to ensure that the power supply is quickly turned back on and no arc is generated. For example, if the power supply set point for welding can be set to 2,000 watts, with a voltage threshold of 11 volts, this lower power setting can be set to 500 watts. Thus, when the upper voltage threshold (which may be a current or power threshold depending on the embodiment) is reached, the output is reduced to 500 watts. (This lower threshold may also be a lower current or voltage setting, or both). Alternatively, instead of setting a lower detection limit, a timing circuit can be used to start supplying current after a set duration. In exemplary embodiments of the invention, such duration may range from 500 ms to 1000 ms. In FIG. 13A, point C represents the time when the output is fed back to the wire 140. It should be noted that the delay shown between point B and point C may be the result of an intentional delay or simply the result of a system delay. At point C, current is fed back to the filler wire. However, since the filler wire still has not touched the welding puddle, the voltage increases while the current does not. At point D the wire contacts the puddle and the voltage and current settle back to the desired working levels. As illustrated, the voltage may exceed the upper threshold before contacting at D, which may occur when the power supply has an OCV level higher than the OCV level of the working threshold. For example, this higher OCV level may be an upper limit set in the power supply as a result of the design or manufacture of the power supply.

13B is similar to that described above, except that the filler wire 140 is in contact with the welding puddle when the output of the power supply increases. In such a situation, the wire never leaves the welding puddle or the wire has been in contact with the welding puddle prior to point C. Since the wire comes into contact with the puddle when the output is turned on again, FIG. 13B shows the points C and D together. Thus, both the current and voltage increase at point E to the desired working setting.

Figure 13c is an embodiment with little or no delay between the output being turned off (point (A)) and the output being turned back on (point (B)), the wire being in contact with the puddle for some time before point (B) do. In the above shown waveforms, the lower threshold is set such that the output turns back on with little or no delay when the lower threshold is reached-whether it's current, power, or voltage. It can be used in the described embodiments. It should be noted that this lower threshold setting can be set using the same or similar parameters as the working upper thresholds or ranges as described herein. For example, this lower threshold can be set based on wire composition, diameter, feed rate, or various other parameters, as described herein. Such an embodiment can minimize the delay in returning to the desired job set points for welding and minimize any necking that may occur in the wire. Minimizing the necking helps minimize the chances of arcing.

14 shows another exemplary embodiment of the present invention. 14 shows an embodiment similar to the embodiment as shown in FIG. 1. However, some components and connections are not shown for clarity. 14 shows a system 1400 in which a thermal sensor 1410 is used to monitor the temperature of the wire 140. The thermal sensor 1410 may be of any known type capable of detecting the temperature of the wire 140. The sensor 1410 may be in contact with the wire 140 or may be coupled to the tip 160 to detect the temperature of the wire. In another exemplary embodiment of the present invention, the sensor 1410 is a type that uses a laser or infrared beam capable of measuring the temperature of a small object-such as the diameter of a filler wire-without contacting the wire 140. to be. In such an embodiment, the sensor 1410 detects the temperature of the wire 140 at a stick in the wire 140-ie at some point between the tip of the tip 160 and the welding puddle. It is positioned to be. The sensor 1410 is also positioned not to sense the temperature of the sensor 1410 and the welding puddle for the wire 140.

The sensor 1410 provides temperature feedback information to the power supply 170 and / or the laser power supply 130 so that control of the system 1400 can be optimized (refer to FIG. 1). And the sensing and control unit 195). For example, the power or current output of the power supply 170 can be adjusted based at least on feedback from the sensor 1410. In other words, in an embodiment of the present invention, the user can enter a desired temperature setting (for a given weld and / or wire 140) or the user input data (wire feed rate, electrode type) for which the sensing and control unit is different. , Etc.), and then the sensing and control unit 195 will at least allow the power supply 170 to maintain the desired temperature.

In such an embodiment, it is possible to account for the heating of the wire 140 that may occur due to the laser beam 110 striking the wire 140 before the wire enters the welding puddle. In embodiments of the present invention, the temperature of the wire 140 can be controlled by controlling the current of the wire 140 only through the power supply 170. However, in other embodiments, at least a portion of the heating of the wire 140 originates from the laser beam 110 impinging on at least a portion of the wire 140. As such, the current or power from the power supply 170 alone may not represent the temperature of the wire 140. As such, the use of the sensor 1410 can help regulate the temperature of the wire 140 through control of the power supply 170 and / or the laser power supply 130.

In another exemplary embodiment (also shown in FIG. 14), the temperature sensor 1420 aims to sense the temperature of the welding puddle. In this embodiment, the temperature of the welding puddle is also coupled to the sensing and control unit 195. However, in another exemplary embodiment, the sensor 1420 may be coupled directly to the laser power supply 130. Feedback from the sensor 1420 may include laser power supply 130 / laser 120. ) Is used to control the output. That is, the energy density of the laser beam 110 can be changed to ensure that the desired welding puddle temperature is achieved.

In another exemplary embodiment of the present invention, instead of directing the sensor 1420 to the puddle, it may be directed to an area of a work piece adjacent to the welding puddle. Specifically, it may be desirable to ensure that heat input to the workpiece adjacent to the weld is minimized. The sensor 1420 may be positioned to monitor this temperature sensitive area such that the threshold temperature is not exceeded near the weld. For example, the sensor 1420 may monitor the work temperature and reduce the energy density of the beam 110 based on the sensed temperature. Such a configuration will ensure that the heat input near the weld bead does not exceed the desired threshold. Such an embodiment can be used for precision welding operations where the heat input to the workpiece is critical.

In another exemplary embodiment of the present invention, the sensing and control unit 195 is connected to a feed force detection unit (not shown) coupled to a wire feeding mechanism (not shown-but see 150 in FIG. 1). Can be combined. The supply force detection units are known and detect the supply force applied to the wire 140 as the wire is supplied to the workpiece 115. For example, such a detection unit can monitor the torque applied by the wire feed motor of the wire feeder 150. If the wire 140 does not completely melt and passes through the melt welding puddle, it will contact the solid portion of the workpiece and such contact will cause the supply force to increase as the motor tries to maintain the set feed rate. . This increase in force / torque is detected, and the control to adjust the voltage, current and / or power for the wire 140 using this information to ensure proper melting of the wire 140 in the puddle. Can be relayed to the unit 195.

It should be noted that in some exemplary embodiments of the present invention, the wire may be supplied intermittently based on a desired welding profile, rather than being continuously supplied into the welding puddle. Specifically, the versatility of various embodiments of the present invention allows an operator or the control unit 195 to start and stop supplying the wire 140 into the puddle as desired. For example, a complex welding profile that can have certain parts of the weld joint that require the use of filler metal (the wire 140) and other parts on the same workpiece that do not require the use of filler metal. There are many different types of fields and geometric structures. As such, during the first part operation of the weld, the control unit 195 can only operate the laser 120 to laser weld this first part of the junction, but the welding operation-the use of filler metal. Required-when reaching the second portion of the weld joint, the controller 195 causes the power supply 170 and the wire supply 150 to deposit the wire 140 into the welding puddle. Let's start. Then, as the welding operation reaches the end of the second portion, the deposition of the wire 140 can be stopped. This makes it possible to create successive welds with a profile that varies significantly from one part to the next. Such an ability allows a workpiece to be welded in a single welding operation, as opposed to having many individual welding operations. Of course, many variations can be implemented. For example, a weld can have three or more distinct parts that require a welding profile with various shapes, depths, and filler requirements, such that the use of the laser and the wire 140 in each weld part can be difficult. . Furthermore, additional wires can also be added or removed as needed. That is, the first welding portion may only require laser welding, while the second portion only requires the use of a single filler wire 140, and the last portion of the welding portion requires the use of two or more filler wires. Shall be The controller 195 can be made to control the various system components to achieve such a varying welding profile in a continuous welding operation, so that the continuous welding beads are in a single weld pass. Is generated.

15 shows a conventional welding puddle P when welding in accordance with exemplary embodiments of the present invention. As described above, the laser beam 110 generates the puddle P on the surface of the workpiece W. The weld puddle has a length (L), shape and movement of the beam (110) that is a function of energy density. In an exemplary embodiment of the invention, the beam 110 is directed from the trailing edge of the welding puddle to the puddle P at a distance Z. In such embodiments, a high intensity energy source (eg, the laser 120) is such that its energy is directly on the filler wire 140 such that the energy source 120 does not melt the wire 140. It makes it collide, but rather the wire 140 is melted due to its contact with the welding puddle. The trailing edge of the puddle P may generally be defined as the point at which the molten puddle ends and the resulting weld bead WB begins to solidify. In an embodiment of the invention, the distance Z is 50% of the length L of the puddle P. In another exemplary embodiment, the distance Z ranges from 40% to 75% of the length L of the puddle P.

As shown in FIG. 15, the filler wire 140 collides with the puddle P behind the beam 110-in the traveling direction of the weld. As shown, the wire 140 collides with the puddle P at a distance X before the trailing edge of the puddle P. In an exemplary embodiment, the distance X ranges from 20% to 60% of the length of the puddle P. In another exemplary embodiment, the distance X ranges from 30% to 45% of the distance L of the puddle P. In other exemplary embodiments, the wire 140 and the beam 110 are at the surface of the puddle P such that at least a portion of the beam 110 impacts the wire 140 during a welding process. Or cross at the point above the puddle (P). In such an embodiment, the laser beam 110 is used to help melt the wire 140 for deposition in the puddle P. If the wire 140 is too cold to be quickly consumed in the puddle P, using the beam 110 to help melt the wire 140 means that the wire 140 is the puddle ( It helps to prevent quenching P). However, as mentioned above, in some exemplary embodiments (as shown in FIG. 15), melting is completed by the heat of the welding puddle, so the energy source 120 and the beam 110 are the filler No part of the wire 140 melts significantly.

In the embodiment shown in FIG. 15, the wire 140 follows the beam 110 and is parallel to the beam 110. However, since the wire 140 may precede (in the advancing direction), the present invention is not limited to this configuration. Further, the wire 140 need not be parallel to the beam in the traveling direction, but the wire may collide with the puddle in any direction as long as proper wire melting occurs in the puddle.

16A to 16F show various puddle Ps having a footprint of the laser beam 110 shown above. As shown, in some example embodiments, the puddle P has a circular footprint. However, embodiments of the present invention are not limited to this configuration. For example, it is conceivable that the puddle may have an oval or other shape.

16A to 16F, the beam 110 is shown to have a circular cross section. In other words, the beam 110 may have an elliptical, rectangular, or other shape to effectively generate the welding puddle P, so other embodiments of the present invention are not limited in this regard.

In some embodiments, the laser beam 110 may remain stationary with respect to the welding puddle P. That is, the beam 110 remains in a consistent position relative to the puddle P during welding. However, other embodiments are not limited to such a scheme, as illustrated in FIGS. 16A-16D. For example, Fig. 16asms shows an embodiment in which the beam 110 is converted into a circular pattern around the welding puddle P. In this figure, the beam 110 is transformed such that at least one point on the beam 110 always overlaps the center C of the puddle. In another embodiment, a circular pattern is used but the beam 110 does not contact the center C. 16B shows an embodiment in which the beam is converted to reciprocate along a single line. This embodiment can be used to elongate or widen the puddle P depending on the desired type of puddle P. 16C shows an embodiment in which two different beam cross sections are used. The first beam cross-section 110 has a first geometry and the second beam cross-section 110 'has a second cross-section. Such an embodiment can be used to increase penetration at points within the puddle while still maintaining a larger puddle size-if necessary. This embodiment can be achieved by changing the beam shape through the use of laser lenses and optics using a single laser 120, or can be achieved through the use of multiple lasers 120. 16D shows the beam 110 converted into an oval pattern in the puddle P. In other words, such a pattern can be used to open or enlarge the welding puddle P as needed. Other beam 110 transformations can be used to generate the puddle P.

16E and 16F show cross sections of the workpiece W and the puddle P using different beam intensities. 16E shows the shallower and wider puddle P produced by the wider beam 110, while FIG. 16F, the deeper and narrower welding puddle P-commonly referred to as a "keyhole"- Is showing. In this embodiment, the beam is focused such that its focus is close to the upper surface of the workpiece W. With such a focal point, the beam 110 may penetrate the entire depth of the workpiece to help create a back bead BB on the bottom surface of the workpiece W. The beam strength and shape should be determined based on the desired properties of the weld puddle during welding.

The laser 120 may be moved, converted or operated through any known methods and devices. Since the movement and optical systems of lasers are generally known, they will not be discussed in detail herein. 17 shows another system 1700 in an exemplary embodiment of the present invention, wherein the laser 120 is moved, and its optical system (such as its lenses) moved, modified or adjusted during operation. Can have The system 1700 couples the sensing and control unit 195 to both the motor 1710 and the optical system drive unit 1720. The motor 1710 moves or converts the laser 120 so that the position of the beam 110 relative to the welding puddle is moved during welding. For example, the motor 1710 may convert the beam to reciprocate, move it in a circular pattern, or the like. Similarly, the optical system drive unit 1720 receives commands from the sensing and control unit 195 to control the optical system of the laser 120. For example, the optical system driving unit 1720 allows the focus of the beam 110 to be moved or changed relative to the surface of the workpiece, thereby changing the penetration or depth of the welding puddle. Similarly, the optical system driving unit 1720 may cause the optical system of the laser 120 to change the shape of the beam 110. As such, during welding, the sensing and control unit 195 controls the laser 120 and beam 110 to maintain and / or change the characteristics of the welding puddle during operation.

In each of FIGS. 1, 14 and 17, the laser power supply 130, hot wire power supply 170 and sensing and control unit 195 are shown separately for clarity. However, in embodiments of the present invention, these components can be manufactured integrally into a single welding system. Aspects of the present invention do not require components individually discussed above to be maintained in separate physical units or stand alone structures.

As described above, the high-intensity energy source may be numerous energy sources, including welding power sources. An exemplary embodiment of this is shown in FIG. 20, showing a system 2000 similar to the system 100 shown in FIG. 1. Many of the components of the system 2000 are similar to the components of the system 100, so their operation and utilization will not be discussed again in detail. However, in the system 2000, the laser system is replaced by an arc welding system, such as a GMAW system. The GMAW system includes a power supply 2130, a wire supply 2150, and a torch 2120. The welding electrode 2110 is delivered to the molten puddle through the wire feeder 215 and the torch 2120. The operation of the GMAW welding system of the type described herein is well known and need not be described in detail herein. Although the GMAW system is shown and discussed in connection with the illustrated exemplary embodiments, exemplary embodiments of the present invention are such systems that use arcs to help transfer consumables into the molten puddle on the workpiece. It should be noted that it may be used with, including, GTAW, FCAW, MCAW, and SAW systems, cladding systems, soldering systems, and combinations of these systems, and the like. A shielding gas system or sub arc flux system, which can be used according to known methods, is not shown in FIG. 20.

As with the laser systems described above, the arcing systems (which can be used as the high-intensity energy source) are the melting furs to which the hot wire 140 is added using systems and embodiments as detailed above. It is used to generate them. However, using the arc generating systems, as known, additional consumables 2110 are also added to the puddle. This additional consumable is in addition to the already increased deposition performance provided by the hot wire process described herein. This performance will be discussed in more detail below.

Also, as is generally known, arc generating systems such as GMAW use a high level of current to generate an arc between the advancing consumable and the molten puddle on the workpiece. Similarly, GTAW systems use a high current level to generate an arc between the electrode and the workpiece, into which consumables are added. As is generally known, many different current waveforms can be used for GTAW or GMAW welding operations, such as constant current, pulse current, and the like. However, during operation of the system 2000, the current generated by the power supply 2130 may interfere with the current generated by the power supply 170 used to heat the wire 140. have. Since the wires 140 are close to the arc generated by the power supply 2130 (because they are each directed to the same melting puddle, similar to those described above), the respective currents are Can interfere. Specifically, each current generates a magnetic field, and these magnetic fields can interfere with each other and negatively affect the operation of the currents. For example, the magnetic fields generated by the hot wire current may inhibit stability of the arc generated by the power supply 2130. That is, without proper control and synchronization between the respective currents, the competing magnetic fields can destabilize the arc and thus destabilize the process. Therefore, exemplary embodiments use current synchronization between the power supplies 2130 and 170 to ensure stable operation, which will be discussed further below.

21 is a more detailed view of an exemplary welding operation of the present invention. As can be seen, the torch 2120 (which may be an exemplary GMAW / MIG torch) delivers consumables 2110 to the welding puddle WP through the use of an arc-as is generally known. In addition, according to any of the embodiments described above, the hot wire consumable 140 is delivered to the welding puddle WP. Although the torch 212 and the tip 160 are shown separately in this figure, it should be noted that these components can be integrally manufactured with a single torch delivering both consumables 2120 and 140 to the puddle. do. Of course, to the extent that an integrated configuration is used, electrical isolation must be used within the torch to prevent current transfer between the consumables during the process. As mentioned above, the magnetic fields induced by the respective currents can interfere with each other, so embodiments of the present invention synchronize the respective currents. Synchronization can be achieved through a variety of methods. For example, the sensing and current controller 195 can be used to control the operation of the current supplies 2130 and 170 to synchronize the currents. Alternatively, if one of the current supply devices is used to control the output of the other, a master-slave relationship can also be used. Control of the relative currents can be accomplished by a number of methods including the use of state tables or algorithms to control the power supplies such that the output currents of the power supplies are synchronized for stable operation. You can. This will be discussed in relation to FIGS. 22A-22C. For example, dual-state based systems and devices similar to those described in US Patent Publication No. 2010/0096373 can be used. United States Patent Publication No. 2010/0096373, published on April 22, 2010, is incorporated herein by reference in its entirety.

Each of FIGS. 22A-22C shows exemplary current waveforms. 22A shows an example welding waveform (GMAW or GTAW) using current pulses 2202 to help transfer droplets from the wire 2110 to the puddle. Of course, the illustrated waveforms are exemplary and representative and not intended to be limiting, for example, the current waveforms are pulsed spray transfer, pulse welding, surface tension transfer welding. , And the like. The hot wire power supply 170 outputs a current waveform 2203 having a series of pulses 2204 to heat the wire 140 through resistance heating as generally described above. . The current pulses 2204 are spaced apart by the background level of the laser current level. As described generally above, the waveform 2203 is used to heat the wire 140 to or near its melting temperature, and the pulses () to heat the wire 140 through resistive heating. 2204) and the background. 22A, the pulses 2202 and 2204 from the respective current waveforms are synchronized so that they are out of phase with each other. In this exemplary embodiment, the current waveforms are controlled such that the current pulses 2202/2204 have similar or identical frequencies and phase with each other as shown. Surprisingly, it has been found that having in-phase waveforms results in a stable and consistent operation, where the arc is not significantly impeded by the heating current generated by the waveform 2203.

22B shows waveforms from another exemplary embodiment of the present invention. In this embodiment, the heating current waveform 2205 is controlled / synchronized such that the pulses 2206 are out of phase with the pulses 2202 by a constant phase angle (Θ). In such an embodiment, the phase angle is selected to ensure stable operation of the process and to ensure that the arc remains stable. In exemplary embodiments of the present invention, the phase angle Θ ranges from 30 degrees to 90 degrees. In other exemplary embodiments, the phase angle is 0 degrees. Of course other phase angles may be used to obtain a stable operation, and may range from 0 degrees to 360 degrees, while in other exemplary embodiments, the phase angle ranges from 0 degrees to 180 degrees.

22C shows another exemplary embodiment of the present invention, wherein the hot wire current 2207 is the phase angle Θ where the hot wire pulses 2208 are with the welding pulses 2202. The phase is different so that it is about 180 degrees, and is synchronized with the welding waveform 2201 so that it occurs only during the background portion 2210 of the waveform 2201. In this embodiment, the respective currents do not reach the peak at the same time. That is, the pulses 2208 of the waveform 2207 start and end during the respective background portions 2210 of the waveform 2201.

In some exemplary embodiments of the invention, the pulse widths of the weld and hot wire pulses are the same. However, in other embodiments, the respective pulse widths may be different. For example, when using a GMAW pulse waveform together with a hot wire pulse waveform, the GMAW pulse width is in the range of 1.5 milliseconds to 2.5 milliseconds, and the hot wire pulse width is in the range of 1.8 milliseconds to 3 milliseconds, and the hot wire The pulse width is greater than the GMAW pulse width.

Although the heating current is shown as a pulse current, it should be noted that for some example embodiments, the heating current may be constant power as described above. The hot wire current may also be pulse heating power, constant voltage, sloped output and / or joule / time based output.

As described herein, to the extent that the two currents become pulse currents, they must be synchronized for stable operation. There are many methods that can be used to accomplish this, including using synchronization signals. For example, the controller 195 (which can be integrated into any of the power supplies 170/2130) sets a synchronization signal to initiate a pulsed arc peak and also the hot You can set the desired start time for the wire pulse peak. As described above, in some embodiments, the pulses will be synchronized to start at the same time, while in other embodiments, the synchronization signal will initiate the start of a pulse peak for the hot wire current after the arc pulse peak. Any duration can be set to elapse-the duration will have to be sufficient to achieve the desired phase angle for the task.

23 shows another exemplary embodiment of the present invention. In this embodiment, a GTAE welding / coating operation is used, where GTAW torch 2121 and electrode 2122 create an arc through which consumables 2120 are delivered. In other words, the arc and the hot wire 140 are delivered to the same puddle WP to create a bead WB as shown. The work of the GTAW embodiment is similar to that described above in that the arc and the hot wire 140 interact with the same welding puddle WP. In other words, as in the case of using the GMAW operation described above, the current used to generate the arc in the GTAW operation is synchronized with the current for the hot wire operation. For example, as shown in Figs. 22A to 22C, a pulse relationship can be used. In addition, the controller 195 may control synchronization between the power supplies using a dual-state table, or other similar control methods. It should be noted that the consumables 2120 may be transferred to the welding portion as cold wires or may be hot wire consumables. That is, as described herein, two consumables 2110 and 140 may be heated. Alternatively, only one of the consumables 2120 and 140 can be a hot wire, as described herein.

In embodiments of the GTAW or GMAW type discussed above (including other arc-like methods), the arc is positioned at the lead-relative to the direction of travel. This is illustrated in FIGS. 21 and 23, respectively. This is because the arc is used to achieve the desired penetration in the work (s). That is, the arc is used to create a molten puddle and achieve the desired penetration in the work (s). Next, a hot wire process, described in detail herein, follows the arc process. The addition of the hot wire process adds more consumables 140 to the puddle without additional heat input of another welding arc, such as in a tandem MIG process where at least two arcs are used. Thus, embodiments of the present invention can achieve significant deposition rates with significantly less heat input than known tandem welding methods.

As shown in FIG. 21, the hot wire 140 is inserted into the same welding puddle WP as the arc, but follows the distance D after the arc. In some exemplary embodiments, this distance ranges from 5 mm to 20 mm, and in other embodiments, the distance ranges from 5 mm to 10 mm. Of course, other distances can be used as long as the wire 140 is fed into the same melting puddle as formed by the preceding arc. However, the wires 2110 and 140 must be deposited on the same melting puddle and the distance D should be such that the interference of the arc by the heating current used to heat the wire 140 is minimized. In general, the size of the puddle, where the arc and the wire enter collectively, is also a factor in determining the desired distance between the wires 2110 and 140, the welding speed, arc parameters, and the wire ( 140) will depend on total power, material type, etc.

When an arc event is detected or predicted by the controller 195 or the power supply 170, the operation of the hot wire current (eg, 2203, 2203, or 2207) is described in detail herein. It should be noted that they are similar. That is, even if the current is pulsed, when an arc is generated or detected, the current may be blocked or minimized as described herein. Furthermore, in some example embodiments, the background portions 2211 are at a current level below the arc generation level for the wire 140 (which may be determined by the controller 195 based on user input information). And instead of blocking the hot wire current when an arc is detected, the power supply 170 (as generally described above) is determined to be absent or not occurring for a duration or for the arc. Until the current can drop to the background level (2211). For example, the power supply 170 may omit a predetermined number of pulses 2203/2205/2207, or may not only pulse for a duration, such as 10 ms to 100 ms. , After the time, the power supply 170 may start pulses again to heat the wire 140 to an appropriate temperature.

As mentioned above, since at least two consumables 140/2110 are used in the same puddle, the heat input is similar to that of a single arc operation, while a very high deposition rate can be achieved. This provides great advantages over tandem MIG welding systems with very high heat input into the workpiece. For example, embodiments of the present invention can easily achieve a deposition rate of at least 23 lb / hr while having a single arc heat input. Other exemplary embodiments have a deposition rate of at least 35 lb / hr.

In exemplary embodiments of the present invention, the respective wires 140 and 2110 are identical in that they have the same composition, diameter, and the like. However, in other exemplary embodiments, the wires may be different. For example, the wires can have different diameters, wire feed rates and composition, as desired for a specific job. In an exemplary embodiment, the wire feed rate for the lead wire 2110 may be higher than for the hot wire 140. For example, the leading wire 2110 may have a wire feed speed of 450 ipm, while the trail wire 140 has a wire feed speed of 400 ipm. In addition, the wires can have different sizes and compositions. Indeed, since the hot wire 140 does not need to pass through the arc to be deposited with the puddle, the hot wire 140 will typically have materials / components that do not transfer well through the arc. You can. For example, the wire 140 may have tungsten carbide, or similar hard facing material, that cannot be added to a conventional welding electrode due to the arc. In addition, the preceding electrode 2110 may have many compositions of wetting agents, which may help wetting the puddle to provide a desired bead shape. In addition, the hot wire 140 may also contain slag elements to help protect the puddle. Therefore, embodiments of the present invention allow great flexibility in weld chemistry. Since the wire 2110 is a leading wire, the arc welding operation, along with the leading wire, provides penetration into the weld joint, where the hot wire provides additional fill to the joint. Be careful.

In some exemplary embodiments of the present invention, the combination of arc and hot wire is to balance the heat input to the weld deposit, while meeting the requirements and limitations of the particular operation to be performed. Can be used. For example, heat from the lead arg helps heat from the arc to obtain the necessary penetration to bond the workpieces and the hot wire is primarily used to fill the joints, It can be increased for bonding applications. However, in cladding or buildup processes, the hot wire feed rate can be increased to minimize dilution and increase buildup.

In addition, because different wire chemistries can be used, a weld joint with different layers can be created, which is traditionally accomplished by two separate passes. The leading wire 2110 may have the chemical properties required for the traditional first pass, while the trailing wire 140 may have the chemical properties needed for the traditional second pass. Further, in some embodiments, at least one of the wires 140/2110 may be a cored wire. For example, the hot wire 140 may be a cored wire having a powder core that deposits a desired material into the welding puddle.

24 shows another exemplary embodiment of current waveforms of the present invention. In this embodiment, the hot wire current 2403 is an AC current that is synchronized with the welding current 2401 (whether it is GMAW or GTAW). In this embodiment, the positive pulses 2404 of the heating current are synchronized with the pulses 2402 of the current 2401, while the negative pulses 2405 of the heating current are the background part of the welding current It is synchronized with the field. Of course, in other embodiments, the synchronization is in that the positive pulses 2402 are synchronized with the background 2406 and the negative pulses 2405 are synchronized with the pulses 2402, It can be reversed. In another embodiment, there is a phase angle between the pulse welding current and the hot wire current. By using the AC waveform 2403, an alternating current (and thus an alternating magnetic field) is used to help stabilize the arc. Of course, other embodiments can be used without departing from the spirit and scope of the invention. For example, in a system using submerged arc welding (SAW) operation, the SAW current waveform can be an AC waveform and the hot wire current waveform is an AC or pulsed DC power waveform, where each The waveforms are synchronized with each other.

It should also be noted that embodiments of the present invention can be used where the welding current is a constant or nearly constant current waveform. In such embodiments, an alternating heating current 2403 can be used to maintain the stability of the arc. The stability is achieved by a constantly changing magnetic field due to the heating current 2403.

25 shows another exemplary embodiment of the present invention, where the hot wire 140 is located between two tandem arc welding operations. In FIG. 25, the arc welding operations are shown as GMAW type welding, but may also be GTAW, FCAW, MCAW or SAW type systems. In the figure, a lead torch 2120 is coupled to the first power supply 2130 and delivers the first electrode 2110 to the puddle through an arc welding operation. The hot wire 140 (deposited as discussed above) trails the leading arc. Pursuing the hot wire 140 is a trailing arc welding operation using the second power supply 2130 ', the second torch 2120', and the second arc welding wire 2110 '. Thus, the configuration is similar to that of a tandem GMAW welding system, but has a hot wire 140 deposited into a common puddle between the torches 2120 and 2120 '. Such an embodiment further increases the rate of deposition of materials into the puddle. It should be noted that embodiments of the present invention may use additional welding torches and / or hot wire consumables in a single operation, and are not limited to the embodiment shown in the figure. For example, more hot wire can be used to deposit additional materials into the puddle during a single pass. As mentioned above, instead of the GMAW processes generally discussed herein, SAW processes can be used. For example, the embodiment shown in FIG. 25 can use leading and trailing SAW processes with a configuration similar to that shown in this figure. Of course, instead of a shielding gas, a granular flux could be used to shield the arcs. The overall method or operation and control, as discussed above, is similarly applicable when using other welding methods such as SAW. For example, FIG. 25A shows example waveforms that can be used in a SAW system with the hot wire described herein. As shown, the leading SAW current waveform 2501 is an AC waveform with a plurality of positive pulses 2503 and a plurality of negative pulses 2505, while the trailing SAW current 2521 is also a plurality. Is an AC waveform having positive pulses 2523 and a plurality of negative pulses 2525, where the trailing waveform 2521 is out of phase with the phase angle α by the preceding waveform 2501. In exemplary embodiments of the present invention, the phase angle α ranges from 90 degrees to 270 degrees. In the illustrated embodiment, the +/- offset between the waveforms 2501 and 2521 differs in that the trailing waveform 2521 has a greater negative offset than the preceding waveform 2501. You should also pay attention to that. In other exemplary embodiments, the offset may be the same, or vice versa. The hot wire current 2510 shown as a pulse current having a plurality of positive pulses 2511 is spaced by a background level 2513, where the waveform 2510 is different from the phase angle α. , Has an offset phase angle (θ). In an exemplary embodiment, the hot wire phase angle θ ranges from 45 degrees to 315 degrees, but is different from the phase angle α.

Although the above discussion was aimed at SAW-type work, it should be noted that other exemplary embodiments using similar synchronization methods may be GMAW, FCAW, MCAW or GTAW-type work, or combinations thereof.

As mentioned above, embodiments of the present invention can significantly increase the deposition of materials into the puddle while maintaining a lower total heat input than traditional tandem systems. However, some example embodiments can produce a higher weld bead (WB) shape than traditional tandem methods. That is, the weld bead WB tends to stand higher above the surface of the workpiece and does not wet as much of the sides of the weld bead WB as tandem systems. Generally, this is because the hot wire 140 will help to quench the puddle following a preceding arc welding operation. Therefore, some exemplary embodiments of the present invention utilize systems and components to help widen or wet out the puddle during a welding / coating operation.

26 shows an exemplary embodiment, where the two GMAW torches 2120 and 2120 'are not lined up, but are placed side by side, as shown, where the hot wire 140 ) Follows the two torches 2120/2120 '. In this embodiment, having the two GMAW arcs in a side-by-side configuration will enlarge the puddle WP and help wet the puddle to flatten the weld bead WB. As in the other embodiments, the hot wire 140 follows the arc welding operation and may be located on the center-line of the welding bead WB behind the arc welding operations. However, since the hot wire 140 may vibrate during the welding operation or move relative to the puddle, the hot wire 140 need not remain at the center line.

27 shows another exemplary embodiment used on both sides of the welding puddle WP to help lasers 2720 and 2720 'flatten the puddle or to wet the puddle. . The lasers 2720/2720 'emit beams 2710/2710' onto the sides of the puddle to add heat to the puddle, and help wet the puddle so that the shape of the puddle is desirable. . The lasers 2720/2720 'may be of the type described herein, and may be controlled as described above. That is, the lasers can be controlled by the controller 195 or similar device to provide the desired weld bead shape. Furthermore, instead of using two lasers to achieve the desired weld bead shape, split the beam 2710 and direct the split beams to an appropriate location on the welding puddle to achieve the desired weld bead shape. With a beam splitter, a single laser can be used. It should be noted that the preceding arc welding process is not shown in FIG. 27 for clarity.

In another exemplary embodiment, a single laser beam 2710 can be used, directed (in the direction of travel) just downstream of the arc process or downstream of the hot wire 140 to the puddle, where the beam 2710 is vibrated from side to side to help flatten the puddle. In such embodiments, a single laser 2720 can be used and aimed at the areas of the puddle, where it is desirable to help wet the puddle during welding. The control and operation of the laser 2720 is similar to the control and operation of the laser 120 described above with reference to FIG. 1 and the like.

28 shows another exemplary embodiment of the present invention. In this exemplary embodiment, a GTAW (or GMAW, FCAW, MCAW) electrode 2801 is used in the arc welding process, and a magnetic probe 2803 is used to control the movement of the arc during welding. ). The probe 2803 receives current from a magnetic control and power supply 2805, which may or may not be coupled to the controller 195, the current being a magnetic field (MF ) Is generated by the probe 2803. The magnetic field interacts with the magnetic field generated by the arc and can thus be used to move the arc during welding. That is, the arc can be moved left and right during welding. This left and right movement is used to help enlarge the puddle and wet the puddle to achieve the desired weld bead shape. Although not shown for clarity, hot wire consumables follow the arc as discussed herein to provide additional filling of the weld bead. The use and implementation of magnetic steering systems are generally known by those skilled in the welding industry and need not be described in detail herein.

Of course, embodiments in either of FIGS. 26 and 28 (as well as other illustrated embodiments described herein) can be used to assist the laser 2720 to assist in the shape of the welding puddle as described herein. ).

Although the invention has been described in connection with certain embodiments, it will be understood by those skilled in the art to which the invention pertains that various modifications may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made without departing from the scope of the present invention, in order to adapt a particular situation or material to the teaching of the present invention. Therefore, the present invention is not intended to be limited to the specific embodiments disclosed, but the present invention is intended to cover all embodiments falling within the scope of the appended claims.

<Reference number>
100: system 110: laser beam
110A: laser beam 110 ': single-sided
115: workpiece 120: laser device
121: beam splitter 125: direction
130: laser power supply 140: filler wire
150: filler wire feeder 160: contact tube
160 ': component 170: hot wire power supply
180: motion controller 190: robot
195: current control subsystem 200: start-up method
210: step 220: step
230: step 240: step
250: Step 260: Step
300: start method 310: step
320: step 330: step
340: Step 350: Step
410: voltage waveform 411: point
412: point 420: current waveform
425: ramp 430: time interval
440: Set point value 450: Current level
510: voltage waveform 511: point
512: point 520: current waveform
525: current level 530: time interval
601: joint surface 601A: molten puddle
603: joint surface 603A: molten puddle
605: surface 701: angled surface
703: sloped surface 705: gap
707: weld bead 801: welding puddle
803: Welding Puddle 901: Welding Puddle
903: welding puddle 1000: welding joint
1010: laser source 1011: beam
1012: welding puddle 1020: laser source
1021: beam 1022: welding puddle
1030: filler wire 1030A: filler wire
1110: induction coil 1200: system
1210: hot wire power supply 1220: user input
1221: positive terminal 1222: negative terminal
1223: Feedback detection lead 1230: CPU / controller
1240: voltage detection circuit 1250: power module
1400: system 1410: thermal sensor
1420: temperature sensor 1700: system
1710: motor 1720: optical system drive unit
1800: circuit 1801: resistor
1803: Switch 1901: Laser shroud assembly
1903: fume extraction system 2000: system
2110: welding electrode 2110 ': welding wire
2120: Torch 2120 ': Second Torch
2121: torch 2122: electrode
2130: Power supply 2130 ': Second power supply
2150: wire feeder 2201: welding waveform
2202: current pulses 2203: current waveform
2204: pulses 2205: current waveform
2206: pulses 2207: hot wire current
2208: hot wire pulses 2210: background part
2211: background parts 2401: welding current
2402: pulses 2403: hot wire current
2404: positive pulses 2405: negative pulses
2406: background parts 2501: current waveform
2503 positive pulses 2505: negative pulses
2510: hot wire current 2511: positive pulses
2513: Background level 2521: SAW current
2523: positive pulses 2525: negative pulses
2710: Beam 2710 ': Beam
2720: laser 2720 ': laser
2801: electrode 2803: magnetic probe
2805: Power supply D: point / distance
E: point G: gap width
I: current L: length
MF: Magnetic field P: Welding puddle
V: Voltage W: Workpiece
W1: Work W2: Work
WB: Welding Bead WP: Welding Puddle
X: Distance traveled Z: Distance
A: Branch B: Branch
C: point / center α: angle
Θ: angle θ: angle

Claims (26)

In the welding system,
Providing an arc generating signal comprising a plurality of current pulses to the electrode to generate an arc between the electrode and the at least one workpiece to create a molten puddle on at least one workpiece An arc generating power supply;
A hot wire power supply device that generates a heating signal including a plurality of heating current pulses to heat the consumable so that the consumable melts in the molten puddle when at least one consumable contacts the molten puddle ( hot wire power supply); And
A controller for synchronizing both the arc generation signal and the heating signal so as to maintain a constant phase angle between the current pulses of the arc generation signal and the heating current pulses.
Including,
At least one of the hot wire power supply and the controller monitors feedback related to the heating signal, compares the feedback to an arc generation threshold, and the hot wire power supply is configured to And turning off the heating signal when the feedback reaches the arcing threshold while in contact with the at least one workpiece. According to claim 1,
The phase angle is in the range of 0 degrees to 180 degrees, the welding system. According to claim 1,
The phase angle is 0 degrees, the welding system. According to claim 1,
The phase angle is in the range of 30 degrees to 90 degrees, the welding system. According to claim 1,
The heating signal is an AC signal, the welding system. According to claim 1,
The electrode is a consumable that is melted by the arc generation signal and deposited into the melting puddle. According to claim 1,
A welding system, wherein the laser beam further comprises at least one laser directed towards the molten puddle to add heat to the molten puddle. According to claim 1,
And at least one magnetic field generating device that generates a magnetic field to interact with the arc. According to claim 1,
Wherein the feedback is based on at least one of heating power, heating current and heating voltage. According to claim 1,
Wherein the feedback is based on a rate of change of at least one of heating power, heating resistance, heating current and heating voltage. In the welding system,
A plurality of first current pulses in the first electrode to generate an arc between the first electrode and the at least one workpiece to create a molten puddle on at least one workpiece A first arc generating power supply for providing a first arc generating signal;
Providing a second arc generating signal including a plurality of second current pulses to a second electrode to generate the second arc between the first electrode and at least one workpiece such that a second arc contacts the melting puddle A second arc generating power supply;
A hot wire power supply device that generates a heating signal including a plurality of heating current pulses to heat the consumable so that the consumable melts in the molten puddle when at least one consumable contacts the molten puddle ( hot wire power supply); And
A controller for synchronizing both the first and second arc generating signals and the heating signal such that a constant phase angle is maintained between the first and second current pulses of the arc generating signal and the heating current pulses.
Including,
At least one of the hot wire power supply and the controller monitors feedback related to the heating signal, compares the feedback to an arc generation threshold, and the hot wire power supply is configured to And turning off the heating signal when the feedback reaches the arcing threshold while in contact with the at least one workpiece. The method of claim 11,
Wherein the first and second arc generating signals are submerged arc welding signals. The method of claim 11,
Each of the first and second arc generating signals and the heating signal are synchronized to be out of phase with each other. The method of claim 11,
Wherein at least one of the first and second arc generating signals is an AC signal. The method of claim 11,
Wherein the feedback is based on at least one of heating power, heating current and heating voltage. The method of claim 11,
Wherein the feedback is based on a rate of change of at least one of heating power, heating current, and heating voltage. In the welding method,
The arc generating signal comprising a plurality of current pulses at the electrode to generate an arc between the electrode and the at least one workpiece to generate an arc generating signal and generate a molten puddle on at least one workpiece. Providing;
Generating a heating signal comprising a plurality of heating current pulses to heat the consumable so that the consumable melts in the molten puddle when at least one consumable contacts the molten puddle;
Synchronizing both the arc generating signal and the heating signal such that a constant phase angle is maintained between the current pulses of the arc generating signal and the heating current pulses; And
Monitor the feedback signal related to the heating signal, compare the feedback to an arc generation threshold and heat the heating if the feedback reaches the arc generation threshold while the at least one consumable contacts the at least one workpiece Turn off the signal
Included, welding method. The method of claim 17,
The phase angle is in the range of 0 to 180 degrees, welding method. The method of claim 17,
The phase angle is 0 degrees, welding method. The method of claim 17,
The phase angle is in the range of 30 degrees to 90 degrees, welding method. The method of claim 17,
The heating signal is an AC signal, the welding method. The method of claim 17,
The electrode is a consumable that is melted by the arc generation signal and is deposited into the melting puddle. The method of claim 17,
The welding method further comprises directing at least one laser beam to the molten puddle to add heat to the molten puddle. The method of claim 17,
The welding method further comprises generating a magnetic field to interact with the arc. The method of claim 17,
Wherein the feedback is based on at least one of heating power, heating current and heating voltage. The method of claim 17,
Wherein the feedback is based on a rate of change of at least one of heating power, heating current and heating voltage.

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