KR20150086550A - Method and system to start and use combination filler wire feed and high intensity energy source for welding - Google Patents

Abstract

A method and system 100 for welding or joining workpieces 115, 115A, 115B, W using a high-strength energy source to create a welding puddle P and at least one resistive filler wire 140 , 1200, 1400, 1700) is initiated and the filler wire is heated to and near its melting temperature and penetrated into the weld puddle (P). The monitoring circuit serves to prevent arcing between the filler wire and the workpiece.

Description

[0001] METHOD AND SYSTEM FOR STARTING AND USING COMBINATION FILLER WIRE FEED AND HIGH INTENSITY ENERGY SOURCE FOR WELDING [0002]

The present application is a continuation-in-part of U.S. Patent Application No. 12 / 352,667, which is a continuation-in-part of U.S. Patent Application No. 13 / 212,025, which claims priority and claims priority. U.S. Patent Application No. 12 / 352,667 and U.S. Patent Application No. 13 / 212,025 are hereby incorporated by reference herein in their entirety.

The invention relates to a welding method according to claim 1 and to a welding system according to claim 10. Some embodiments relate to welding and connection applications as well as filler wire overlaying applications. Some embodiments relate to welding and joining applications as well as filler wire overlay applications. More particularly, certain embodiments provide a system and method for activating and using a combined filler wire feeder and energy source system for either brazing, cladding, building up, filling, surface strengthening overlaying, joining and welding applications .

A typical filler wire method of welding (e.g., gas-tungsten arc welding (GTAW) filler wire method) provides an increased deposition rate and welding speed over the typical deposition rate of the arc welding alone do. The filler wires leading to the torch are resistively heated by separate power supplies. The wire is fed through the contact tube toward the workpiece and extends past the tube. The extension is resistance-heated so that the extension approaches or reaches the melting point and contacts the welding puddle. A tungsten electrode may be used to heat and melt the workpiece to form the welding puddles. The power supply provides most of the energy needed to resist-melt the filler wire. In some cases, the wire feeder may be slip or unstable, and current in the wire may cause an arc to arise between the tip of the wire and the workpiece. The additional heat of these arcs can cause burnthrough and spatter. The risk of this arc occurrence is greater at the beginning of the process where the wire initially contacts the workpiece at a small point. If the initial current in the wire is too large, the point is burned out and an arc is generated.

The general, typical, and proposed techniques will be apparent to those skilled in the art through a comparison of the techniques described above with embodiments of the present invention as outlined in the remainder of the application with reference to the drawings.

The object of the present invention is to overcome the above limitations and disadvantages. Another object of the present invention is to minimize the risk of arc generation.

This problem is solved by a welding method according to claim 1 and by a welding system according to claim 10. Other embodiments are subject to dependent claims. Embodiments of the present invention include a system and method for activating and using a combined filler wire feeder and energy source system. A first embodiment of the present invention includes a combined filler wire feeder for a brazing, cladding, building up, fill, surface strengthening overlay, joining and welding application and a method for starting and using the energy source system do. The method includes applying a sensing voltage across a power source between at least one resistive filler wire and the workpiece and moving the distal end of the at least one resistive filler wire toward the workpiece. The method further includes sensing when the distal end of the at least one resistive filler wire first contacts the workpiece. The method also includes turning off power to at least one resistive filler wire for a limited time interval in response to sensing. The method further includes turning on the power at the end of the defined time interval to apply the heating current flow through the at least one resistive filler wire. The method also includes applying energy from the high-strength energy source to the workpiece to heat the workpiece during application of at least the flow of heating current. The high-strength energy source may be a laser device, a plasma arc welding (PAW) device, a gas tungsten arc welding (GTAW) device, a gas metal arc welding (GMAW) device, a flux core arc welding (FCAW) device, and a submerged arc And a welding (SAW) device.

These and other features of the invention as well as details of the described embodiments of the invention will be more fully understood from the following description and drawings.

1 is a functional schematic block diagram of an exemplary embodiment of a combined filler wire feeder and energy source system for either brazing, cladding, building up, fill, surface hardening overlay application.
Figure 2 is a flow diagram of an embodiment of a start-up method used by the system of Figure 1;
3 is a flow chart of an embodiment of a post-startup method used by the system of FIG.
Figure 4 illustrates a first exemplary embodiment of a pair of voltage waveforms and current waveforms associated with the back-up method of Figure 3;
Figure 5 illustrates a second exemplary embodiment of a pair of voltage waveforms and current waveforms associated with the post-start method of Figure 3;
Figures 6 and 6A show another exemplary embodiment of the present invention used to perform a welding operation.
Figures 7, 7A and 7B show further exemplary embodiments of welding using the present invention.
Figure 8 shows another exemplary embodiment for joining both sides of a joint simultaneously.
Figure 9 shows another exemplary embodiment of a weld using the present invention.
10 illustrates another exemplary embodiment of the present invention in which a joint is welded with a plurality of lasers and wires.
11A-11C illustrate an exemplary embodiment of a contact tip used in conjunction with an embodiment of the present invention.
12 illustrates a hot-wire power supply system in accordance with an embodiment of the present invention.
Figures 13A-13C illustrate voltage and power waveforms generated in accordance with an exemplary embodiment of the present invention.
Figure 14 illustrates another welding system in accordance with an exemplary embodiment of the present invention.
15 illustrates an exemplary embodiment of a welding fur produced by an embodiment of the present invention.
16A-16F illustrate an exemplary embodiment of a welding puddle and laser beam use in accordance with an embodiment of the present invention.
Figure 17 illustrates a welding system according to another exemplary embodiment of the present invention.
Figure 18 illustrates an exemplary embodiment of a ramp down circuit that may be used in embodiments of the present invention.
19 illustrates an exemplary embodiment of a fume extraction nozzle according to the present invention.
20A is a view showing a result of a thin wall welding process using an arc welding process;
Figure 20b shows the results of an exemplary embodiment of a thin wall welding process using the present invention.

The term "overlaying" is used herein in a broad sense and includes the steps of brazing, cladding, building up, filling, and hardening- Any application may be mentioned. For example, in the "brazing" application, the filler material is dispersed between the surfaces of the joint that are closely fitted through the capillary action. On the other hand, in the "braze welding" application, the filler material is made to flow into the gap. However, as used herein, both techniques are broadly referred to as overlaying applications.

1 is a functional schematic block diagram of an exemplary embodiment of an energy source system 100 and a combined filler wire feeder for performing either brazing, cladding, building up, filling, surface strengthening overlaying, and bonding / / RTI > The system 100 includes a laser subsystem capable of focusing the laser beam 110 on the workpiece 115 to heat the workpiece 115. The laser subsystem is a high energy source. The laser system may be any kind of high energy laser source, including, but not limited to, carbon dioxide, Nd: YAG, Yb-disk, YB-fiber, fiber transmission or direct diode laser systems. A white light or quartz light laser type system can also be used if it has sufficient energy. Other embodiments of the system include an electron beam, a plasma arc welding subsystem, a gas tungsten arc welding subsystem, a gas metal arc welding subsystem, a flux core arc welding subsystem, and a submerged arc welding subsystem System, and the like. The following description will repeatedly refer to the laser system, the beam and the power supply, but 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 operatively connected to each other. The laser power supply 130 supplies power to operate the laser device 120.

The system 100 also includes a hot filler wire feeder subsystem that can provide at least one resistive filler wire 140 to make contact with the workpiece 115 in the vicinity of the laser beam 110. Of course, the fur melted based on the workpiece 115 in the present specification is regarded as a part of the workpiece 115, and therefore the reference to the contact with the workpiece 115 is the contact with the puddle 115 . 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 that guides the laser beam 100 is resiliently biased by a current from a hot-wire welding power supply 170 operatively connected between the contact tube 160 and the workpiece 115, And heated. In accordance with an embodiment of the present invention, the hot wire power supply 170 is a pulsed DC current (DC) power supply, although alternating current (AC) or other types of power supply is also possible. The wire 140 is fed from the filler wire feeder 150 through the contact tube 160 toward the workpiece 115 and extends past the tube 160. The extension of the wire 140 approaches the melting point or reaches the melting point before resistance-heating and contacting the welding puddle on the workpiece. The laser beam 110 serves to melt a portion of the base metal of the workpiece 115 to form the welding puds and to melt the wire 114 onto the workpiece 115. The power supply 170 provides most of the energy needed to resist-melt the filler wire 114. According to another embodiment of the present invention, the feeder subsystem may simultaneously provide one or more wires. For example, a first wire may be used to reinforce the surface and / or to provide corrosion resistance to the workpiece, and a second wire may be used to add the structure to the workpiece.

The system 100 further includes a motion control system that can move the laser beam 100 (energy source) and each filler wire 140 in the same direction 125 (at least relatively) along the workpiece 115 So that the laser beam 110 and the resistive filler wire 140 remain in a fixed relationship with respect to each other. Relative movement between the workpiece 115 and the laser / wire combination can be achieved by either substantially moving the workpiece 115 or by moving the laser device 120 and the hot wire feeder subsystem . In Figure 1, the motion controller subsystem includes a motion controller 180 operatively connected to a robot 190. The motion controller 180 controls the motion of the robot 190. The robot 190 is operatively connected (e.g., mechanically fixed) to the workpiece 115 to move the workpiece 115 in the direction 125 to move the laser beam 110 and the wire 140, Moves along the workpiece 115 in effect. 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 can be moved along the workpiece 115 through a motion control subsystem operatively connected to the head.

Generally, there are a number of ways in which a high strength energy source / hot wire can be moved relative to the workpiece. If the workpiece has a round shape, the high-strength energy source / hot wire may be stationary and the workpiece may be rotated about a high-strength energy source / hot wire. Alternatively, the robot arm or linear tractor may move in parallel with the curved workpiece, and as the workpiece is rotated to cover, for example, the surface of the curved workpiece, the high-strength energy source / Or indexed once per revolution. If the workpiece is not flat or at least not curved, the workpiece can be moved under the high-strength energy source / hot wire as shown in Fig. However, a robotic arm or linear tractor or beam-mounted cartridge may also be used to move the high-strength energy source / hot wire head relative to the workpiece.

The system 100 further includes a sensing and current control subsystem 195. This subsystem is operatively connected to the workpiece 115 and the contact tube 160 (i.e., substantially connected to the output of the hot wire power supply 170) I) and the hot wire 140 (that is, the voltage V). The sensing and current control subsystem 195 may further calculate a resistance value (R = V / I) and / or a power value (P = V * I) from the measured voltage and current. Generally, when the hot wire 140 is in contact with the workpiece 115, the potential difference between the hot wire 140 and the workpiece 115 is zero volts or almost zero volts. As a result, as will be described in greater detail below, the sensing and current control subsystem 195 can sense when each filler wire 140 is in contact with the workpiece 115, And is operatively connected to a hot wire power supply 170 to further control the flow of current through each filler wire 140. In accordance with another embodiment of the present invention, the sense and current controller 195 may be an integral part of the hot wire power supply 170.

In accordance with an embodiment of the present invention, the motion controller 180 may be further operatively coupled to the laser power supply 130 and / or the sense and current controller 195. In this manner, the motion controller 180 and the laser power supply 130 can communicate with each other so that the laser power supply 130 knows when the workpiece 115 is moving, (120) is in an operating state. Similarly, in this manner, the motion controller 180 and the sense and current controller 195 can communicate with each other so that the sense and current controller 195 knows when the workpiece 115 is moving and the motion controller 180 ) Knows whether the hot filler wire feeder subsystem is operational. Such communication may be used to coordinate activities among the various subsystems of system 100.

FIG. 2 shows a flow diagram of an embodiment of the start-up method 200 used by the system 100 of FIG. In step 210, a sensing voltage is applied between the at least one resistive filler wire 140 and the workpiece 115 through the power supply unit 170. [ Under the command of the sense and current controller 195, the sense voltage can be applied by the hot wire power supply 170. Also, in accordance with an embodiment of the present invention, the applied sense voltage does not provide sufficient energy to heat the wire 140 significantly. At step 220, the distal end of at least one resistive filler wire 140 is advanced towards the workpiece 115. This advancement is performed by the wire feeder 150. At step 230, it senses when the distal end of at least one resistive filler wire 140 first contacts the workpiece 115. For example, the sense and current controller 195 may direct the hot wire power supply 172 to provide a very low level of current (e. G., 3 to 5 amps) through the hot wire 140. This sensing can be accomplished using a filler wire 40; For example, by a sensing and current controller 195 that measures a potential difference of about zero volts (e.g., 0.4 volts) between the workpiece 115 and the workpiece 115 (e.g., via the contact tube 160). A significant voltage level is applied between the filler wire 140 and the workpiece 115 when the end of the resistive filler wire 140 is short-circuited to the workpiece 115 (i.e., when making contact with the workpiece) (0 volts or more) can not exist.

At step 240, the power supply 170 is turned off for at least one resistive filler wire 140 over a limited time interval (e.g., a few milliseconds) in response to sensing. The sense and current controller 195 may command the power supply 170 to turn off. At 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 sense and current controller 195 may command the power supply 170 to turn on. In step 260, energy is applied from the high-strength energy source 110 to the workpiece 115 to heat the workpiece 115 at least during application of the flow of heating current.

Optionally, the method 200 stops the advancement of the wire 140 in response to sensing, resumes (i.e., re-advances) the advance of the wire 140 at the end of the defined time interval, And confirming that the end of the filler wire 140 is still in contact with the workpiece 115 prior to application. The sense and current controller 195 may instruct the wire feeder 150 to stop supplying and command the system 100 to wait (e.g., a few milliseconds). In this embodiment, sensing and current controller 195 is operatively connected to wire feeder 150 to command wire feeder 150 to start and stop. The sensing and current controller 195 may instruct the hot wire power supply 170 to apply a heating current to the wire 140 and to supply the wire 140 back to the workpiece 115. [

Upon termination of the start-up method, the system 100 may be programmed to cause the laser beam 110 and the hot wire 140 to contact the workpiece 110 to perform either brazing, cladding, build-up, surface hardening, or welding / The user may enter a post-start mode of operation that is moved relative to the drive 115. FIG. 3 is a flow diagram of an embodiment of a post-startup method 300 utilized by the system 100 of FIG. In step 310, a high-intensity energy source (e.g., laser device 120) and at least one resistive filler wire 140 are moved along the workpiece 115 to form an end of at least one resistive filler wire 140 (E.g., laser device 120) or at least one resistive filler wire 140 is supplied toward the workpiece 115 in accordance with a high-intensity energy source, the high-intensity energy source (E.g., laser beam 110) and / or heated workpiece 115 (laser beam 110, laser device 120). (That is, the workpiece 115 is heated by the laser beam 110) melts the end of the filler wire 145 onto the workpiece 115. The motion controller 180 instructs the robot 190 to move the workpiece 114 relative to the laser beam 110 and the hot wire 140. A laser power supply 130 provides power to operate the laser device 120 to form a laser beam 110. The hot wire power supply 170 provides current to the hot wire 140 as it is commanded by the sense and current controller 195.

In step 320, the sensing is performed when the distal end of at least one resistive filler wire 140 provides breakage of the membrane contact with the workpiece 115 (i.e., provides premonition capability). This detection is performed by a potential difference (dv / dt) between the filler wire 140 and the workpiece 115, a current (di / dt) through the filler wire and the workpiece, a resistance between the filler wire and the workpiece dr / dt), or a sense circuit in the sense and current controller 195 that measures the rate of change of the power (dp / dt) through the filler wire and the workpiece. When the rate of change exceeds a predefined value, the sense and current controller 195 officially predicts that a loss of contact has just occurred. This intelligent circuit is known in the art for arc welding.

 When the end of the wire 140 is significantly melted by heating, the end begins to pinch off from the workpiece 115 at the wire 140. For example, at that time, as the end of the wire is detached, the potential difference or voltage increases because the cross-section of the end of the wire is sharply reduced. Thus, by measuring the rate of such a change, the system 100 can predict when the end is peeled off and the contact with the workpiece 115 is broken. Also, if the contact is completely lost, a potential difference (e. G., Voltage level) that is significantly greater than zero volts can be measured by the sense and current controller 195. If the operation at step 330 is not taken, this potential difference may cause an arc to form between the new end of the (undesirable) wire 140 and the workpiece 115. Of course, in other embodiments, the wire 140 may not exhibit any notable detachment, but rather will flow into the puddle in a continuous form while maintaining a substantially constant cross-section towards the puddles.

At step 330, the end of at least one resistive filler wire 140 breaks the flow of heating current through the at least one resistive filler wire 140 in response to detecting that the contact with the workpiece 115 is broken (step < RTI ID = 0.0 > Or at least to a great extent, for example up to 95%). The controller 195 instructs the hot wire power supply 170 to shut off (or at least greatly reduce) the current supplied to the hot wire 140 when the sensing and current controller 195 determines that the contact is lost . This prevents the formation of unwanted arcs and prevents any undesirable effects such as splatter or burn-through from occurring.

At step 340, a wire 140 that continues to move toward the workpiece 115 senses when the end of at least one resistive filler wire 140 comes into contact with the workpiece 115 again. This sensing can be accomplished using filler wires [140; By means of a sensing and current controller 195 measuring the potential difference of about zero volts between the workpiece 115 and the workpiece (i. E., Via the contact tube 160). When the end of the filler wire 140 is short-circuited to the workpiece 115 (that is, when it comes into contact with the workpiece), a significant difference between the filler wire 140 and the workpiece 115 The voltage level can not exist. The phrase "again touches" is used herein to refer to whether the wire 140 is moved toward the workpiece 115, whether or not the end of the wire 140 is actually detached from the workpiece 115, Is used to refer to a situation where the measured voltage between the workpiece 115 (e.g., via the contact tube 160) and the workpiece 115 is about zero volts. In step 350, the flow of heating current through the at least one resistive filler wire is reapplied in response to sensing that the end of the at least one resistive filler wire is in contact with the workpiece again. To continue heating the wire 140, the sense and current controller 195 may command the hot wire power supply 170 to apply the heating current again. This process may continue during the overlaying period.

For example, FIG. 4 illustrates a first exemplary embodiment of a pair of voltage and current waveforms 410 and 420, respectively, associated with the post-start method 300 of FIG. The voltage waveform 410 is sensed and measured by the current controller 195 between the contact tube 160 and the workpiece 115. The current waveform 420 is sensed by the wire 140 and the workpiece 115 and measured by the current controller 195.

Each time the end of the resistive filler wire 140 breaks contact with the workpiece 115, the rate of change of the voltage waveform 410 (i.e., dv / dt) will exceed the set threshold, (See slope at point 411 in waveform 410). Alternatively, the rate of change (di / dt) of current through the filler wire 140 and the workpiece 115, the rate of change in resistance between the filler wire and the workpiece dr / dt) or the rate of change of power (dp / dt) through the filler wire and the workpiece may be used instead. This rate of change prediction technique is known in the art. At some point in time, the sense and current controller 195 will command the hot wire power supply 170 to break (or at least greatly reduce) the flow of current through the wire 140.

After the sensing and current controller 195 has some time interval 430 (e.g., the voltage level drops back to about zero volts at point 412), the end of the filler wire 140 is again in good contact with the workpiece 115 The sense and current controller 195 is configured to increase the flow of current toward the set output current level 450 through the resistive filler wire 140 (see slope 425) And supplies it to the supply unit 170. In accordance with an embodiment of the present invention, the increment begins at the set point value 440. [ This process repeats as the energy source 120 and the wire 140 move relative to the workpiece 115 and because the wire feeder 150 moves the wire 140 toward the workpiece 115 do. In this way, contact between the end of the wire 140 and the workpiece 115 is substantially maintained, and an arc is prevented from being formed between the end of the wire 140 and the workpiece 115. An increase in the heating current helps to prevent unintentional interpretation of the rate of change of voltage as a falling state or an arc state when the falling state or arc state is not present. Any large-scale current change can result in an imperfect voltage that is interpreted to be caused by the inductance in the heating current. When the current is gradually increased, the effect of the inductance is reduced.

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

Each time the end of the resistive filler wire 140 breaks contact with the workpiece 115, the rate of change of the voltage waveform 510 (i.e., dv / dt) will exceed the set threshold, (See slope at point 511 in waveform 510). Alternatively, the rate of change (di / dt) of current through the filler wire 140 and the workpiece 115, the rate of change in resistance between the filler wire and the workpiece dr / dt) or the rate of change of power (dp / dt) through the filler wire and the workpiece may be used instead. This rate of change prediction technique is known in the art. At some point in time, the sense and current controller 195 will command the hot wire power supply 170 to break (or at least greatly reduce) the flow of current through the wire 140.

After the sensing and current controller 195 has some time interval 530 (e.g., the voltage level drops back to about zero volts at point 512), the end of the filler wire 140 is again in good contact with the workpiece 115 The sensing and current controller 195 instructs the hot wire power supply 170 to apply a flow of heating current through the resistive filler wire 140 (see the heating current level 525) . This process repeats as the energy source 120 and the wire 140 move relative to the workpiece 115 and because the wire feeder 150 moves the wire 140 toward the workpiece 115 do. In this way, contact between the end of the wire 140 and the workpiece 115 is substantially maintained, and an arc is prevented from being formed between the end of the wire 140 and the workpiece 115. In this case, since the increase in the heating current is not gradually increasing, any voltage reading can be ignored as unintended and incomplete due to the inductance in the heating current.

In summary, a method and system for launching and using a combined wire feeder and energy source system for either brazing, cladding, building up, fill and surface hardening overlay applications is disclosed. High-intensity energy is applied to the workpiece to heat the workpiece. One or more resistive filler wires are fed toward the picked crop with the applied high energy energy or just before the applied high intensity energy. Sensing occurs when the end of the one or more resistive filler wires contacts the workpiece at or near a high intensity energy applied thereto. The electrical heating current for one or more resistive filler wires is controlled based on whether the end of the one or more resistive filler wires is in contact with the workpiece. The applied high strength energy and one or more resistive filler wires move in the same direction along the workpiece in a fixed relationship relative to each other.

In another exemplary embodiment, the systems and methods of the present invention are used for welding and welding operations. The embodiment described above focuses on the use of filler metal in the overlay operation. However, aspects of the present invention may be used for welding and joining applications where workpieces are joined using welding operations and through the use of filler metals. Even with regard to overlaying filler metals, the embodiments, systems and methods described above are similar to those used in welding operations and are more fully described below. It is understood, therefore, that the description above is generally applied to the following description, unless otherwise indicated. In addition, the following description may include references to Figs. 1-4.

Welding / bonding operations are typically known to bond a plurality of workpieces together in a welding operation where the filler material bonds with at least a portion of the workpiece metal to form a joint. Because of the desire to increase production throughput in welding operations, there is a continuing need for faster welding operations that do not result in welds with a standard quality. There is also a need to provide a system that can be quickly welded under adverse work environments, such as in a remote worksite. As described above, the exemplary embodiments of the present invention provide significant advantages over existing welding techniques. These advantages include, but are not limited to, reduced total heat input to reduce twisting of the workpiece, very high welding travel speed, very low spatter rate, unshielded welding, very little sputtering or high speed plating without sputtering Welded or coated materials, and welding composites at high speeds.

In an exemplary embodiment of the present invention, a very high welding speed is obtained using coated workpieces, as compared to arc welding, which typically requires significant preparation work and is a much slower welding process using arc welding methods . By way of example, the following description will focus on galvanized workpiece welding. Metallic zinc plating is used to increase the corrosion resistance of metals and is desirable for many industrial applications. However, general welding of galvanized workpieces can be problematic. In particular, during welding, zinc in the galvanizing is vaporized and as the pellets solidify, the zinc vapor can be trapped in the welding puddle, resulting in porosity. This porosity has an adverse effect on the strength of the welded joint. Because of this, existing welding techniques require a first step of welding at low process speed and with some level of defect removal or galvanization through galvanizing - this is inefficient and leads to delays, Proceed slowly. By slowing down the process, the weld puddle remains molten for a long time allowing vaporized zinc to escape. However, due to the low speed, the production rate is slow and the total heat input into the weld can be high. Other coatings that cause similar problems include, but are not limited to, paints, stamping lubricants, glass lining, aluminum coatings, surface heat treatment, nitridation or carbonization, cladding or other vaporization coatings or materials. As described below, an exemplary embodiment of the present invention eliminates this problem.

Returning to Figures 6 and 6a, a representative weld lap joint is shown. In this figure, two coated (e.g., galvanized) workpieces W1 and W2 are joined by lap welding. The lap joint surfaces 601 and 603 as well as the surface 605 of the workpiece W1 are initially covered with a coating. In a typical welding operation (e.g., MIG (metal inert gas) welding), a portion of the covered surface 605 is melted. This is due to the general depth of penetration of standard welding operations. Because the surface 605 melts, the coating on the surface 605 is vaporized, but the distance of the surface 605 from the surface of the welding pool is large, so that the gas can become trapped as the weld pool solidifies. This does not occur in the embodiment of the present invention.

6 and 6A, the laser beam 110 is directed from the laser device 120 to the weld joint, particularly to the surfaces 601 and 603. The laser beam 110 has an energy density to dissolve a portion of the weld surface that produces the melting puddles 601A and 603A, which produces normal weld puddles. The filler wire 140 (which is resistance heated as previously described) is also directed to the weld puddle to provide the filler material needed for the weld bead. Unlike most welding processes, during the welding process the filler wire 140 contacts the welding puddle and fits within the welding puddle. This is because this process simply dissolves the filler wire into the welding puddle rather than using the welding arc to transfer the filler wire 140.

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

Since the laser beam 110 can be focused precisely and directed to the surfaces 601/603, the depth of penetration with respect to the pool 601A / 603A can be precisely controlled. By carefully controlling this depth, embodiments of the present invention prevent any unwanted penetration or melting of the surface 605. No coating on surface 605 is vaporized and is not trapped in the weld puddle because surface 605 is not over-melted. Also, any coating on the surfaces of the weld joints 601 and 603 is easily vaporized by the laser beam 110, and this gas is allowed to escape the welding zone before the welding puddle is hardened. It is contemplated that a gas extraction system may be utilized to aid in the removal of any vaporized coating material.

Since the welding puddle penetration depth can be precisely controlled, the welding speed of the coated workpiece can be greatly increased, while the porosity is significantly reduced or eliminated. Although some arc welding systems can achieve good running speeds for welding, problems such as porosity and spatter can occur at higher speeds. In an exemplary embodiment of the present invention, a very high throughput rate can be achieved with little porosity or spatter or porosity or spatter (as discussed herein) and, in fact, for many other types of welding operations, 50 inches / The process speed of more than a minute can be easily achieved. Embodiments of the present invention can achieve a welding progress speed of 80 inches / minute or more. Further, as discussed herein, other embodiments may achieve a throughput rate in the range of 100-150 inches / minute with minimal porosity or sputtering or without porosity or sputtering. Of course, the achieved speed will be a function of workpiece characteristics (thickness and component) and wire characteristics (e.g., diameter), but in many other welding and bonding applications when using embodiments of the present invention, It is possible. These rates can also be achieved with 100% CO 2 shielding gas and without any shielding gas. In addition, this progress speed can be achieved without creating any surface coatings prior to the generation and welding of the welding puddles. It is, of course, contemplated that a greater progress rate may be achieved. In addition, due to the reduced heat input into the weld, this high speed can be achieved in the thinner workpiece 115. [ Here, a thinner workpiece typically has a slower welding speed because the heat input must be kept low to prevent distortion. Embodiments of the present invention can achieve very high deposition rates with low mixing ratios as well as high throughput rates as described above with little porosity or sputtering or porosity or sputtering. In particular, embodiments of the present invention can achieve a deposition rate of 10 lb / hr or greater without shielding gas and with less porosity or spatter or porosity or spatter. In some embodiments, the deposition rate is in the range of 10 to 20 lb / hr.

In an exemplary embodiment of the present invention, this very high throughput rate is achieved with little porosity and spatter or without porosity and spatter. The porosity of the weld may be determined by testing the cross-section and / or length of the weld bead to determine the porosity ratio. The cross-sectional porosity ratio is the total area of porosity in a given cross-section to the total cross-sectional area of the weld joint at this point. The length porosity ratio is the total cumulative length of the pores within a given unit length of the weld joint. Embodiments of the present invention can achieve the abovementioned progress speed with a cross-sectional porosity of 0 to 20%. Thus, a weld bead without bubbles or cavities will have a porosity of 0%. In other exemplary embodiments, the cross-sectional porosity may be in the range of 0 to 10%, and other exemplary embodiments may be in the range of 2 to 5%. It is understood that some levels of porosity may be tolerated in some welding applications. Further, in an exemplary embodiment of the present invention, the length porosity of the weld is in the range of 0 to 20% and may be 0 to 10%. In another exemplary embodiment, the length porosity ratio may be in the range of 1 to 5%. Thus, for example, weldments having cross-sectional porosity in the range of 2 to 5% and length porosity of 1 to 5% can be produced.

In addition, embodiments of the present invention can be welded at an ascending speed identified above with little or no spatter. Spatter occurs when small droplets of weld puddle are caused to bounce out of weld zone. When a welding spatter occurs, the welding spatter can jeopardize the quality of the welding and may cause production delays as the spatter must generally be cleaned from the workpiece after the welding process. Therefore, there is a great advantage in welding at high speed without a spatter. Embodiments of the present invention can be welded at a high traveling speed with a sputter factor in the range of 0 to 0.5 where the spatter factor is the weight of the consumed filler wire 140 over the same distance X Kg) of the spatter over a given travel distance (X).

That is: Spatter factor = (spatter weight (mg) / consumed filler wire weight (Kg)).

The distance (X) should be a distance from a representative specimen of the weld joint. That is, if the distance X is too short, say 0.5 inches, it may not represent welding. Thus, a weld joint with a sputter factor of 0 will not have a spatter on the consumed filler wire over distance X, and a weld with a spatter factor of 2.5 will yield 5 kg of consumed filler wire mg of spatters. In an exemplary embodiment of the present invention, the sputter factor is in the range of 0 to 1. In another exemplary embodiment, the sputter factor is in the range of 0 to 0.5. In another exemplary embodiment of the present invention, the sputter factor is in the range of 0 to 0.3. It should be noted that embodiments of the present invention can achieve the sputtering factor range described above with or without the use of any external masking agent. Wherein the outer shielding agent comprises a shielding gas or a flux shielding agent. Also, the above sputtering factor ranges can be achieved when welding uncoated or coated workpieces, including galvanized workpieces that do not have zinc plating removed prior to the welding operation.

There are a number of ways to measure the spatter on weld joints. One method involves the use of a "spatter boat ". For this method, a representative welding specimen is placed in a container of sufficient size to detach all spatters or almost all spatters generated by the weld bead. To ensure that the spatters are trapped, the container or part of the container, such as the top, may move in accordance with the welding process. Typically the boat is made of copper, so the spatter does not stick to the surface. Typical welding is performed on the bottom of the container so that any spatter generated during welding will fall into the container. do. The amount of consumed filler wire during the welding is monitored. After the welding is completed, the spatter boat is weighed by a device with sufficient accuracy to determine the difference between before and after welding of the container, if any. This difference represents the weight of the spatter and then divided by the amount of Kg units of consumed filler wire. Alternatively, if the spatters do not stick to the boat, the spatters can be removed and only weighed.

As previously described, the use of the laser device 120 takes into account precise control of the depth of the weld puddle. In addition, the use of the laser device 120 allows for easy adjustment of the size and depth of the weld puddle. This is because the laser beam 110 can be easily focused / focused or has a beam intensity that changes very easily. Because of this capability, the heat distribution on the workpieces W1 and W2 can be accurately controlled. This control takes into account not only the creation of very narrow weld pawls for precise welding but also the minimization of the dimensions of the weld zone on the workpiece. This also provides the advantage of minimizing the area of the workpiece, which is not affected by the weld bead. In particular, the area of the workpiece adjacent to the weld bead will be minimally affected by the welding operation, which is often not the case with arc welding operations.

In an exemplary embodiment 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 vary the depth of penetration at some location on the workpiece or to vary the dimensions of the weld bead. In such an embodiment, 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 can impact the weld puddle in the same manner as the laser beam 110. In an exemplary embodiment, the filler wire 140 impacts the weld puddle at the same location as the laser beam 110. However, in another exemplary embodiment, the filler wire 140 may impact the same weld puddle away from the laser beam. In the embodiment shown in FIG. 6A, the filler wire 140 follows the beam 110 during the welding operation. However, this is not necessary as the filler wire 140 can be located at the foremost position. The present invention is not limited in this respect as the filler wire 140 can be located at a different position with respect to the beam 110 as long as the filler wire 140 impacts the same weld puddle as the beam 110. [

The embodiments described above have been described with respect to workpieces having coatings such as zinc plating. However, embodiments of the present invention can also be used on workpieces that do not have coatings. In particular, the same welding process described above can be used with uncoated workpieces. Some embodiments achieve the same performance attributes as described above with respect to the coated metal.

In addition, the exemplary embodiments of the present invention are not limited to welded workpieces, but may also be used to weld aluminum or aluminum-composite metal as described further below.

Another advantageous aspect of the present invention relates to a shielding gas. In a typical arc welding operation, a shielding gas or shielding flux is used to prevent atmospheric oxygen and nitrogen or other harmful components from interacting with the weld puddle and metal transfer. Such intervention can be detrimental to the quality and appearance of the welded product. Thus, in almost all arc welding processes, shielding can be achieved by consuming fluxed electrodes (e.g., stick electrodes, plug core electrodes, etc.) thereon or by externally supplied particle fluxes (e.g., sub- By the use of an externally supplied shielding gas produced by the < / RTI > In addition, in some welding operations, such as welding-specific metals or welded galvanized workpieces, certain shielding gas mixtures must be used. Such a mixture can be quite expensive. Also, when welding in extreme environments, it is sometimes difficult to transport large quantities of shielding gas to workplaces (such as pipelines), or the wind tends to blow off the shielding gas from the arc. The use of fume extraction systems has also grown in recent years. While this system tends to remove fumes, the system also tends to remove shielding gas if it is located adjacent to the welding workshop.

The benefits of the present invention include that a minimum amount of shielding gas may be used when welding or no shielding gas may be used. Alternatively, embodiments of the present invention allow the use of shielding gas that would not normally be used for a particular welding operation. This is further described below.

When welding a typical (uncoated) workpiece with an arc welding process, a shielding agent is required - regardless of its shape. It has been found that no shielding agent is required when welding in an embodiment of the present invention. This means that shielding gas, granule flux and self shielding electrodes need not be used. However, unlike in an arc welding process, the present invention produces high quality welds. That is, the welding speed described above can be achieved without the use of any shielding agent. This can not be achieved with prior art arc welding processes.

During a typical arc welding process, the filler wire is moved from the filler wire to the welding puddle through the welding arc. During transfer without shielding, the entire surface of the droplet is exposed to the atmosphere and tends to acquire nitrogen and oxygen in the atmosphere and transfer nitrogen and oxygen to the welding puddle. This is undesirable.

The filler wire is not exposed to the atmosphere because the invention transfers the filler wire to the weld without the use of a droplet. Therefore, in many welding applications, the use of shielding agents is not required. As such, embodiments of the present invention can achieve high welding rates with little or no porosity or spatter or porosity or spatter, but also without the use of shielding gases.

The fume extraction nozzle can be positioned closer to the weld joint during welding, without the use of shielding agents, thus providing more efficient and effective fume extraction. When a shielding gas is used, it is necessary to locate the fume extraction nozzle in a position where the fume extraction nozzle does not interfere with the function of the shielding gas. Because of the advantages of the present invention, these limitations do not exist and fume extraction can be optimized. For example, in an exemplary embodiment of the present invention, the laser beam 110 is protected by a laser shroud assembly 1901 that protects the beam from the laser device 120 to the surface of the workpiece 115 . A representative configuration thereof can be shown in Fig. During operation, a shroud 1901 (shown in cross-sectional view) protects the beam 110 from interference and provides additional safety. The shroud may also be coupled to a fume extraction system 1903 that extracts welding fumes from the weld zone. Because the embodiment can be used without shielding gas, the shroud 1901 can be positioned very close to the weld to extract the fume directly from the weld zone. In fact, the shroud 1901 can be positioned such that the distance Z over the weld is in the range of 0.125 to 0.5 inches. Of course, other distances may be used, but the circumference must be tilted so as not to interfere with the welding puddle or the effect of the shroud 1901 is not significantly reduced. This configuration and operation will not be described in detail herein, since the fume extraction system 1903 is generally understood and well known in the welding industry. Although FIG. 19 illustrates a shroud 1901 that only protects the beam 110, it is of course possible to configure the shroud 1091 such that the shroud at least surrounds the contact tip 160 with at least a portion of the wire 140 Do. For example, it is possible that the bottom opening of the shroud 1901 is substantially wide enough to cover the entire weld puddle or wider than the weld puddle to increase fume extraction.

In an exemplary embodiment of the present invention used to weld a coated workpiece such as a galvanized workpiece, a much cheaper shielding gas may be used. For example, 100% CO ₂ shielding gas can be used to weld many different materials, including mild steel. It is also true that when welding more complex metals such as stainless steels, mixed steels and super-mixed steels, they can only be welded with 100% nitrogen shielding gas. In a typical arc welding operation, the welding of stainless steels, mixed steels or super-precast steels requires a more complex mixture of shielding gases, which can be quite expensive. Embodiments of the present invention allow these steels to be welded with only 100% nitrogen shielding gas. Other embodiments may also have these steels welded without shielding gas. In a typical welding process on galvanized materials, a special mixed shielding gas such as an argon / CO ₂ mixture should be used. This type of gas needs to be used in part because the cathode and anode are present in the welding zone during normal arc welding. However, as described above and as will be further described below, there is no welding arc and there are no anodes and cathodes in the usually speaking weld zone. Thus, the opportunity for the filler metal to acquire harmful elements from the atmosphere is significantly reduced as there is no arc and no volume transition. It should be noted that although many embodiments of the present invention may enable welding without the use of shielding agents, such as shielding gases, gas flow can be used across the weld to remove gases or contaminants from the welding zone. That is, it can be considered that during welding, air, nitrogen, CO ₂ , or other gas may be called over the weld to remove contaminants from the weld zone.

In addition to being able to weld coated materials at high speeds, embodiments of the present invention can also be used to weld two-phase textured steel with a significantly reduced heat affected zone (HAZ). The two-phase textured steel is a high strength steel with a ferrite and martensite microstructure, thus allowing the steel to have high strength and good formability. Due to the nature of the two-phase textured steel, the strength of the two-phase textured steel weld is limited by the strength of the heat affected zone. The heat affected zone is the area around the weld joint (not including the filler metal), which is significantly heated from the welding process and the microstructure is reversed due to the arc welding process. In a known arc welding process, the heat affected zone is considerably wider due to the dimensions of the arc plasma and the high heat input to the welding zone. Since the heat affected zone is considerably wider, the heat affected zone is the strength limiting part of the weld. Thus, arc welding processes typically use mild steel filler wires 140 to weld such joints (e.g., ER70S-6, or -3 type electrodes) since the use of high strength electrodes is unnecessary. Also, for this reason, the designer strategically positions the welded joint in a two-phase structure steel outside the high-stress structure such as a vehicle frame, a bumper, an engine rocking platform, and the like.

As discussed above, the use of laser device 120 provides a high degree of precision in the creation of weld puddles. Because of this precision, the heat affected zone surrounding the weld bead can be kept very small, or the overall effect of the heat affected zone on the workpiece can be minimized. In fact, in some embodiments, the heat affected zone of the workpiece can be largely eliminated. This is accomplished by maintaining the focus of the laser beam 110 only on the portion of the workpiece on which the pawls are to be created. By significantly reducing the dimensions of the heat affected zone, the strength of the base metal is not compromised as much as if an arc welding process were used. As such, the presence or location of the heat affected zone is no longer a limiting factor in the design of the welded structure. Embodiments of the present invention contemplate the use of higher strength filler wires because the composition and strength of the workpiece and the strength of the filler wire may be a significant factor in the structural design rather than the heat affected zone. For example, embodiments of the present invention enable the use of electrodes having an at least 80 ksi yield strength, such as ER80S-D2 type electrodes. Of course, this electrode is intended to be exemplary. Also, since there is less overall heat input from arc welding, the cooling rate of the puddle will be faster, which will result in a leaner of the chemical properties of the filler wires used but will result in the same or greater performance It means that you can do it.

Additionally, an exemplary embodiment of the present invention may be used to weld titanium with significantly reduced shielding requirements. It is known that when titanium is welded with an arc welding process, considerable care must be taken to ensure that acceptable welds are produced. This is because titanium has strong affinity for reacting with oxygen during the welding process. The reaction between titanium and oxygen produces titanium dioxide, which if present in the welding pool can significantly reduce the strength and / or ductility of the weld joint. Because of this, it is necessary to provide a significant amount of trailing shielding gas to shield the trailing fusing plow as well as the arc from the atmosphere as the puddles cool as the titanium is arc welded. Because of the heat generated from the arc welding, the weld puddles can be quite wide and can remain molten for long periods of time, thus requiring a significant amount of shielding gas. Embodiments of the present invention significantly shorten the time at which the material is melted and rapidly cool down, thus reducing the need for this additional shielding gas.

As described above, the laser beam 110 can be very carefully focused to significantly reduce the total heat input into the weld zone, thus significantly reducing the size of the weld puddle. The weld puddle is cooled much faster because the weld puddle is smaller. Thus, no trailing shielding gas is required, but only shielding to the welds is required. Also, for similar reasons described above, the spatter factor is significantly reduced when welding titanium, while the welding speed is increased.

Returning to Figures 7 and 7a, an open root welded joint is shown. Open root joints are commonly used to weld thick plates and pipes and can occur in distant and environmentally difficult locations. (SMAW), Gas Tungsten Arc Welding (GTAW), Gas Metal Arc Welding (GMAW), Flux Core Arc Welding (FCAW), Submerged Arc Welding There are many known methods including flux core arc welding-magnetic shielding (FCAW-S). This welding process has various disadvantages including the necessity of shielding, speed limitation, generation of slag, and the like.

Thus, embodiments of the present invention greatly improve the efficiency and the speed at which this type of welding can be performed. In particular, the use of shielding gas can be eliminated or greatly reduced, and the occurrence of slag can be completely eliminated. In addition, welding at high speeds with minimum spatter and porosity can be obtained.

Figures 7 and 7A illustrate a representative open root welded joint being welded in accordance with an exemplary embodiment of the present invention. Of course, embodiments of the present invention may be used to weld a wide variety of weld joints as well as lap joints or open root joints. In Fig. 7A, a gap 705 between the workpieces W1 / W2 is shown, and each workpiece has a sloped surface 701/703. As just discussed above, embodiments of the present invention utilize the laser device 120 to produce precise melt puddles on surfaces 701/703, and use preheated filler wires (not shown) as described above ) Are welded into the puddle.

In fact, the exemplary embodiments of the present invention are not limited to a single pillar wire being directed to each welding puddle. One or more filler wires can be directed to either weld puddle because no weld arc occurs in the welding process described herein. By increasing the number of fillers for a given weld puddle, the overall deposition rate of the welding process can be significantly increased without a significant increase in heat input. That is, it is contemplated that an open root weld joint (such as that shown in Figures 7 and 7a) may be filled in a single weld pass.

7, in some exemplary embodiments of the present invention, multiple laser beams 110 and 110A may be used to simultaneously melt one or more locations within a weld joint. This can be done in a number of ways. In the first embodiment shown in Fig. 7, a beam splitter 121 is used and is coupled to the laser device 120. Fig. The beam splitter 121 is known to those skilled in the art of laser devices and need not be discussed in detail herein. Beam splitter 121 may split the beam from laser device 120 into two (or more) distinct beams 110 / 110A and direct them to two different surfaces. In this embodiment, multiple surfaces can be simultaneously irradiated and provide additional precision and accuracy in welding. In another embodiment, each of the individual beams 110 and 110A may be generated by a separate laser device so that each beam is emitted by its own dedicated device.

In this embodiment using multiple laser devices, many aspects of the welding operation can be varied to meet different welding needs. For example, a beam generated by an individual laser device may have different energy intensities; And may have different shapes and / or different cross-sectional areas in the weld joint. Modes of the welding process can be modified and tailored using this flexibility to perform any specific welding parameters required. Of course, this can also be done with the use of a single laser device and a beam splitter 121, but some flexibility can be limited to the use of a single laser source. Further, the present invention is not limited to single and dual laser configurations, considering that any number of lasers may be used as desired.

In another exemplary embodiment, a beam scanning device may be used. Such a device is well known in the laser or beam emission arts and is used to scan the beam 110 in a pattern on the surface of the workpiece. With this apparatus, the scan speed and pattern and the dwell time can be used to heat the workpiece 115 in a desired manner. In addition, the output power of an energy source (e.g., laser) can be adjusted as needed to produce the desired puddle shape. Additionally, the optical components used in the laser device 120 may be optimized based on desired work and joint parameters. For example, line and integral optics can be used to create a linear beam for a wide welding or cladding operation, or an integrator can be used to produce a square / rectangular beam with a uniform power distribution Can be used.

Figure 7a illustrates another embodiment of the present invention in which a single beam 10 faces the open root joint to melt the surface 701/703.

Due to the precision of the laser beams 110 and 110A, the beam 110 / 110A can be focused only on the surface 701/703 and off in the gap 705. Because of this, the melt-through can normally be controlled (to fall through the gap 705), which significantly improves control of the backside weld bead (weld bead at the bottom surface of the gap 705) do.

7 and 7A, a gap 705 is present between the workpieces W1 and W2, which is filled with the weld bead 707. As shown in Fig. In an exemplary embodiment, the weld bead 705 is created by a laser device (not shown). Thus, for example, a first laser device (not shown) may apply a first laser beam (not shown) to the gap 705 to weld the workpieces W1 and W2 with the laser weld bead 707 during the welding operation, While the second laser device 120 directs at least one laser beam 110 / 110A to surface 701/703 to produce weld puders, wherein the filler wire (s) (not shown) ) Is welded to complete the welding. If the gap is small enough, the gap weld bead 707 can be created only by the laser, or, if the gap 705 requires, the gap weld bead can be created by the use of laser and filler wires. In particular, it may be necessary to add filler metal to suitably fill the gap 705, and therefore filler wires should be used. The creation of this gap bead 705 in connection with various embodiments of the present invention is similar to that described above.

It should be noted that a high intensity energy source, such as the laser device 120 described herein, should be of a type with an output sufficient to provide the inevitable energy density for the desired welding operation. That is, the laser device 120 must have sufficient power to generate and maintain stable weld puddles during the welding process and must also reach the desired penetration. For example, in some applications, the laser should have the ability to "keyhole" the workpiece being welded. This means that while the laser has to have enough power to completely penetrate the workpiece, the extent of penetration must be maintained as the laser moves along the workpiece. Exemplary lasers must have an output capability in the range of 1 to 20 kW and an output capability in the range of 5 to 20 kW. Larger output lasers can be used, but can be very expensive. Of course, it is noted that the use of beam splitter 121 or multiple lasers can also be used for other types of weld joints and can be used for lap joints such as those shown in Figures 6 and 6A.

Figure 7b illustrates another exemplary embodiment of the present invention. In this embodiment, a narrow groove, deep open root joint is shown. When arc welding a deep joint (depth greater than one inch) it may be difficult to weld the bottom of the joint when the gap G about the groove is narrow. This is because it is difficult to efficiently transfer the shielding gas into these deep grooves and the narrow walls of the grooves can interfere with the stability of the welding arc. Since the workpiece is typically an iron-containing material, the walls of the joint may magnetically interfere with the welding arc. For this reason, when using a typical arc welding procedure, the gap G of the groove needs to be sufficiently wide so that the arc remains stable. However, the wider the groove, the more filler material is needed to complete the weld. These problems are minimized because embodiments of the present invention do not require shielding gas and do not use a welding arc. This enables embodiments of the present invention to weld deep and narrow grooves efficiently and effectively. For example, in an exemplary embodiment of the present invention, when the workpiece 115 has a thickness greater than one inch, the gap width G is in the range of 1.5 to 2 times the diameter of the filler wire 140, The sidewall angle is in the range of 0.5 to 10 degrees. In an exemplary embodiment, the root pass preparation of such a weld joint may have a gap (RG) in the range of 1 to 3 mm with lands in the range of 1/16 to 1/4 inch. Thus, a deep open root joint can be welded faster and with less filler material than a normal arc welding process. Also, because of the aspect of the present invention that allows less heat to enter the welding zone, a tip 160 may be designed to facilitate transmission closer to the welding puddle to prevent contact with the sidewall. That is, the tip 160 can be made smaller and can be configured as an insulated guide with a narrow structure. In another embodiment, a transfer device or mechanism may be used to move the laser and wire across the width of the weld to simultaneously weld both sides of the joint.

As shown in Fig. 8, a butt joint can be welded in an embodiment of the present invention. 8, a flat boot-type joint is shown, but it is contemplated that a boot-type joint with a V-notch groove on the top and bottom surfaces of the weld joint may also be welded. In the embodiment shown in FIG. 8, two laser devices 120 and 120A are shown on each side of the weld joint, and each of the laser devices produces its own welding puddles 801 and 803. The heated filler wires are not shown in FIGS. 7 and 7A as the heated filler wires follow the laser beam 110 / 110A.

When welding a boot-type joint with a known arc welding technique, there may be a significant problem in "arc blow" that occurs when the magnetic fields generated by the welding arc interfere with each other and arcs move irregularly to each other have. There may also be a significant problem caused by the interference of the welding current when two or more arc welding systems are in use to weld on the same weld joint. Additionally, due to the penetration depth of the arc welding method, the thickness of the workpiece, which can be welded to the arc on each side of the weld joint due to the partial-high heat input, is limited. That is, such welding can not proceed on a thin workpiece.

When welding in an embodiment of the present invention, this problem is eliminated. There is no arc blow interference or welding current interference problem because there is no welding arc used. In addition, thinner workpieces can be simultaneously welded on both sides of the weld joint due to precise control of the depth of heat input and penetration possible through the use of lasers.

Another exemplary embodiment of the present invention is shown in Fig. In this embodiment, two laser beams 110 and 110A, which are in alignment with one another, are used to produce a unique weld profile. In the illustrated embodiment, the first beam 110 (emitted from the first laser device 120) is used to create a first portion of the weld puddle 901 having a first cross-sectional area and depth , A second beam 110A (emitted from a second laser device, not shown) is used to create a second portion of the weld puddle 903 having a second cross-sectional area and depth that is different from the first cross- do. This embodiment can be used when it is desirable to have a portion of the weld bead having a depth greater than the remainder of the weld bead. For example, as shown in FIG. 9, the puddles 901 are made deeper and narrower than the weld puddles 903 made wider and shallower. When the workpiece meets a deep penetration level, this embodiment can be used when a deep penetration level is required, but not for the whole part of the weld joint.

In another exemplary embodiment of the present invention, the first puddle 903 can be a weld puddle that produces a weld to the joint. This first puddle / joint is created with a first laser device 120 and a filler wire (not shown) and is made to the proper penetration depth. After this weld joint is made, a second laser device (not shown) that emits a second laser beam 110A passes over the joint to create second puddles 903 with different profiles, These second pellets are used to weld some kind of overlay as has been done. This overlay will be deposited using a second filler wire having a different chemical nature than the first filler wire. For example, embodiments of the present invention may be used to position the corrosion resistant cladding layer on a weld joint shortly after or immediately after the joint is welded. This welding operation may also consist of a single laser device 120 wherein the beam 110 is vibrated between a first beam shape / density and a second beam shape / density to provide a desired weld puddle profile. Therefore, it is not necessary to use a plurality of laser devices.

As described above, the corrosive coating on the workpiece (such as zinc plating) is removed during the welding process. However, it may be desirable to have a re-coated welded joint for corrosion-resistant purposes, so that the first beam 110A and the second beam 1102 may be used to add a corrosion resistant overlay 903, such as a cladding layer, A laser can be used.

Because of the various advantages of the present invention, it is also possible to easily join other metals through a welding operation. Other materials for the filler material and the desired chemical properties can cause cracking and inferior welding, so it is difficult to join other metals to the arc welding process using an arc welding process. This is especially true when trying to arc-weld aluminum and steel together with very different melting temperatures due to their different chemical properties, or when trying to weld stainless steels to mild steel. However, this problem is alleviated by the embodiment of the present invention.

Figure 10 illustrates an exemplary embodiment of the present invention. Although a V-shaped joint is shown, the present invention is not limited in this respect. In Fig. 10, two unequal metals are shown joined in the weld joint 1000. In this example, the two unequal metals are aluminum and steel. In this exemplary embodiment, two different laser sources 1010 and 1020 are used. However, two laser devices are not required in all embodiments, as a single device may be vibrated to provide the energy necessary to melt two different materials - this will be further described below. The laser source 1010 emits a beam 1011 towards the workpiece and the laser source 1020 emits a beam 1021 towards the workpiece. Because each workpiece consists of different metals or alloys, they have different melting temperatures. As such, each of the laser beams 1011/1021 in the welding puds 1012 and 1022 has different energy intensities. Because of different energy intensities, each of the welding puddles 1012 and 1022 can be maintained at an appropriate size and depth. It also prevents excessive penetration and heat input in workpieces having a low melting temperature, for example aluminum. In some embodiments, at least because of the weld joint, there is no need to have two separate, separate weld pawls (as shown in FIG. 10). More precisely, a single weld puddle can be formed of both workpieces, wherein the molten portion of each workpiece forms a single weld puddle. It is also possible to use a single beam to irradiate both workpieces simultaneously if the workpieces have different chemical properties but have a similar melting temperature, and it is possible to use more than one workpiece It will be melted. Also, as briefly described above, it is possible to use a single energy source (such as laser device 120) to illuminate both workpieces. For example, to melt the first workpiece, the laser device 120 may utilize a first beam shape and / or energy density and then use a second beam shape and / or energy to melt the second workpiece It can be vibrated / changed in density. Vibration and variations of the beam characteristics must be achieved at a sufficient rate to ensure that the welding puddle (s) remain stable and consistent during welding processes so that proper melting of both workpieces is maintained. Other single beam embodiments may use a beam 110 having a shape that provides more heat input into one workpiece than other workpieces to ensure sufficient melting of each workpiece. In this embodiment, the energy density of the beam must be uniform across the cross section of the beam. For example, because of the shape of the beam, the beam 110 may have a trapezoidal or triangular shape such that the total heat input to one workpiece is less than the heat input to the other workpiece. Alternatively, some embodiments may utilize beam 110 having a non-uniform energy distribution in the cross-section. For example, the beam 110 may have a rectangular shape (impacting the workpiece), but a first region of the beam will have a first energy density and a second region of the beam 110 will have a first energy density Region will have a second energy density. Thus, each of the regions can properly melt each workpiece. By way of example, the beam 110 may have a first region having a high energy density to melt the steel workpiece, while a second region may have a low energy density to melt the aluminum workpiece.

In Figure 10, two filler wires 1030 and 1030A are shown, with each filler wire being directed to a weld puddle 1012 and 1022. [ Although the embodiment shown in FIG. 10 uses two filler wires, the present invention is not limited in this regard. It is contemplated that only one filler wire may be used, or more than two wires may be used, depending on the desired weld parameters such as desired bead shape and deposition rate, as discussed above with respect to other embodiments. When a single wire is used, the wire may be directed to a common fur (formed by the molten portion of the work piece), or the wire may be directed to only one fused portion for integration into a weld joint. Thus, for example, in the embodiment shown in FIG. 10, the wire may be directed to the molten portion 1022, which will then be combined with the molten portion 1012 for the formation of a weld joint. Of course, if a single wire is used, it must be heated to a temperature that allows the wire to melt within the portion 1022/1012 where the wire is to be contained.

Since other metals are connected, the chemistry of the filler wire should be chosen to ensure that the wire can be sufficiently bonded to the metal to which it is connected. In addition, the components of the filler wire (s) should be selected to have a suitable melting temperature, which allows the filler wires to melt and be consumed within the weld puddle of the low temperature weld puddle. In fact, it is contemplated that the chemical properties of a number of film wires may be different in order to obtain adequate weld chemistry. This is especially true when two different workpieces have a material composition that causes minimal mixing between the materials. 10, the low temperature weld puddle is aluminum weld puddle 1012, so filler wire (s) 1030A are made to melt at similar temperatures so that filler wires can easily be consumed within puddle 1012 .

In the above example, when using aluminum and steel workpieces, the filler wire may be silicon bronze, nickel aluminum bronze or aluminum bronze based wire having a melting temperature similar to the melting temperature of the workpiece. Of course, it is contemplated that the filler wire composition must be selected to meet the desired mechanical and welding performance characteristics, while at the same time providing melting characteristics similar to the melting characteristics of at least one of the workpieces to be welded.

Figures 11A-11C illustrate various embodiments of the tip 160 that may be used. 11A shows a tip 160 that is very similar in construction and operation to a conventional arc welding contact tip. During hot wire welding as described herein, the heating current is directed from the power supply 170 to the contact tip 160 and from the tip 160 to the wire 140. The current is then directed to the workpiece through contact of the wire 140 to the workpiece W via the wire. This current flow, as described herein, causes the wire 140 to heat up. Of course, as shown, the power supply 170 may not be directly coupled to the contact tip, but may be coupled to a wire feeder 150 that provides current to the tip 160. 11b illustrates another embodiment of the present invention wherein the tip 160 is comprised of two elements 160 and 160 'and the cathode terminal of the power supply 170 is coupled to the second element 160' . In this embodiment, the heating current flows from the first tip element 160 to the wire 140 and then flows into the second tip element 160 '. The wire is heated by the flow of current through wire 140 between elements 160 and 160 'as described herein. 11C illustrates another exemplary embodiment in which tip 160 includes an induction coil 1110 that causes tip 160 and wire 140 to be heated through induction heating. In this embodiment, the induction coil 1110 may be integral with the contact tip 160, or it may be wrapped around the surface of the tip 160. Of course, other configurations for the tip 160 may be used to transfer the heating current / power to the wire 140 that require the tip to allow the wire to reach the desired temperature for the welding operation.

The operation of an exemplary embodiment of the present invention will be described. As discussed above, embodiments of the present invention utilize 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 is noted that it is not intended to replace or supersede any of the explanations provided above with respect to the following discussion and previously discussed overlaying embodiments, and is intended to supplement these descriptions for welding or joining applications. The previous description of the overlay operation is also included in connection and welding purposes.

An exemplary embodiment for bonding / welding may be similar to the embodiment shown in Fig. As described above, a hot wire power supply 170 is provided that provides heating current to the filler wire 140. The current travels from the contact tip 160 (which can be of any known construction) to the wire 140 and then to the workpiece. This resistive heating current causes the wire 140 between the tip 160 and the workpiece to reach a melting temperature or a temperature near the melting temperature of the filler wire 140 in use. Of course, the melting temperature of the filler wire 140 will vary depending on the dimensions and chemical properties of the wire 140. Thus, the desired temperature of the filler wire during welding will vary according to the wire 140. As will be discussed further below, the desired operating temperature for the filler wire may be data entered into the welding system such that the desired wire temperature is maintained during welding. In any case, the temperature of the wire must be such that the wire is consumed into the weld puddle during the welding operation. In an exemplary embodiment, at least a portion of the filler wire 140 is solid as the wire enters the weld puddle. For example, at least 30% of the filler wire is solid as the wire enters the weld puddle.

In an exemplary embodiment of the present invention, the hot wire power supply 170 supplies a current that maintains at least a portion of the filler wire at a temperature of 75% or more of its melting temperature. For example, when using the mild steel filler wire 140, the temperature of the wire before entering the puddle may be about 1,600 [deg.] F, while the wire has a melting temperature of about 2,000 [deg.] F. Of course, it is understood that each melting temperature and the desired operating temperature will vary depending on at least the alloy, component, 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 of 90% or more of its melting temperature. In another exemplary embodiment, the portion of the filler wire is maintained at a temperature of the wire that is 95% or more of its melting temperature. In an exemplary embodiment, the wire 140 will have a temperature gradient from where the heating current is delivered to the wire 140 and puddles, where the temperature in the puddles is higher than the temperature at the input point of the heating current. It is desirable to have the highest temperature of the wire 140 at or near the point where the wire enters the puddle to facilitate efficient melting of the wire 140. Thus, the temperature percentages mentioned above are measured on the wire at or near the point where the wire enters the puddle. The wire 140 is easily melted or consumed into the weld puddle created by the heat source / laser device 120, by holding the filler wire 140 at or near the melting temperature of the filler wire. That is, the wire 140 is a temperature that does not cause significant quenching of the weld puddle when the wire 140 contacts the puddle. Because of the high temperature of the wire 140, the wire melts quickly when contacting the weld puddle. It is preferred that the wire has a wire temperature so that it is not on the floor in the welding pool and does not contact the unfused portion of the welding pool. Such contact can adversely affect the quality of the weld.

As described above, in some exemplary embodiments, the complete melting of the wire 140 may be facilitated only by the entry of the wire 140 into the puddle. However, in another exemplary embodiment, the wire 140 can be completely melted by the combination of the puddle and the laser beam 110 affecting the portion of the wire 140. In another embodiment of the present invention, the heating / melting of the wire 140 can be assisted by the laser beam 110, which contributes to the heating of the wire 140. However, since many filler wires 140 are made of a reflective material, if the reflective laser type is used, the surface reflectance of the wire is reduced to allow the beam 110 to contribute to the heating / melting of the wire 140 Wire 140 should be heated to a temperature. In an exemplary embodiment of this configuration, wire 140 and beam 110 intersect at the point where wire 140 enters the puddle.

1, the power supply 170 and the controller 195 control the heating current for the wire 140 so that during the welding the wire 140 is in contact with the workpiece And no arcing occurs. Contrary to arc welding techniques, the presence of an arc when welding in an embodiment of the present invention can cause significant weld defects. Thus, in some embodiments (such as the embodiment discussed above), the voltage between the wire 140 and the weld puddle should be maintained at zero volts or nearly zero volts - because the wire is shorted to the workpiece / weld puddle Indicating contact.

However, in another exemplary embodiment of the present invention, it is possible to provide current at this level so that a voltage level of zero volts or more is obtained without an arc being generated. It is possible to maintain the electrode 140 at a higher level and at a temperature close to the melting temperature of the electrode by utilizing a higher current value. This allows the welding process to proceed faster. In an exemplary embodiment of the present invention, the power supply 170 monitors the voltage and provides voltage to the voltage supply 170 (to ensure that no arc is generated as the voltage reaches or approaches the voltage value at some point above zero volts) Stops the flow of current to the wire 140. [ Due to the type of welding electrode 140 in use, the voltage threshold level will typically vary at least in part. For example, in some embodiments of the invention, the threshold voltage reference is 6 volts or less. In another exemplary embodiment, the threshold criterion 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 a mild steel filler wire, the threshold level for voltage is the lower limit, while the filler wire for stainless steel welding can handle higher voltages before the arc is generated.

In another exemplary embodiment, rather than maintaining a voltage level below the threshold, the voltage is maintained within the operating range. In this embodiment, at a melting temperature of the filler wire or near the melting temperature, but keeping the voltage above a minimum amount which ensures a high current sufficient to hold the filler wire below the voltage level so that no welding arc is generated . For example, the voltage may be maintained within a range of 1 to 16 volts. In another exemplary embodiment, the voltage is maintained in the range of 6 to 9 volts. In another example, the voltage may be maintained at 2 to 16 volts. Of course, the desired working range may be influenced by the filler wire 140 used for the desired welding operation, so that the range used for the welding operation based at least in part on the characteristics of the used filler wire or filler wire used Or a threshold value) is selected. In utilizing this range, the lower limit of the range is set for the voltage at which the filler wire can be sufficiently consumed in the weld puddle, and the upper limit of the range is set for the voltage to prevent the generation of an arc.

As previously described, as the voltage exceeds the desired threshold voltage, the heating current is cut off by the power supply 170 and no arc is generated. This aspect of the invention will be further described 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 this type of circuit is known to those skilled in the art. However, these circuits are typically used to maintain voltage above a certain threshold for arc welding.

In another exemplary embodiment, the heating current may also be monitored and / or adjusted by power supply 170. In addition to the monitoring voltage, power or some level of voltage / amperage characteristics, this can be done as an alternative. That is, the current can be maintained at the desired level or level, but still below the arc generated current level, to ensure that the wire 140 is maintained at the proper temperature for proper consumption in the welding puddle. For example, in this embodiment, the voltage and / or current is monitored to ensure that one or both of the voltage and current are within a certain range or below a desired threshold. The power supply then adjusts the supplied current to ensure that no arcs are generated, but to ensure that desired operating parameters are maintained.

In another exemplary embodiment of the present invention, the heating power (V x I) may also be monitored and adjusted by the power supply 170. In particular, in this embodiment, the voltage and current relating to the heating power are monitored such that they are maintained at a desired level or within a desired range. Thus, the power supply can regulate both current and voltage as well as regulate the voltage or current to the wire. This embodiment can provide improved control over the welding system. In such an embodiment, the heating power for the wire may be set to an upper critical threshold level or an optimal operating range (similar to that described above with respect to voltage) so that the power is maintained below the critical level or within the desired range. Once again, the threshold or range setting will be based on the characteristics of the filler wire and the welding being performed, and may be based, at least in part, on the selected filler wire. For example, the optimal power setting for a mild steel electrode with a diameter of 0.045 inches is in the range of 1950 to 2050 watts. The power supply will adjust the voltage and current so that power is kept within this operating range. Similarly, if the power threshold is set at 2000 watts, the voltage supply will adjust the voltage and current so that the power level does not exceed this threshold but approaches this threshold.

In another exemplary embodiment of the present invention, the power supply 170 monitors the rate of change dv / dt of the heating voltage, the rate of change of current di / dt, and / or the rate of change of power dp / . Such circuits are often referred to as predictive circuits, and their general configuration is known. In this embodiment, the rate of change of voltage, current, and / or power is monitored and the heating current to wire 140 is broken if 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 this embodiment, the resistance in the wire between the contact tip and the puddle is monitored. During welding, as the wire is heated, the wire begins to neck down and tends to form an arc, during which the resistance in the wire increases exponentially. When this increase is sensed, the output of the power supply, as described herein, is cut off to ensure that an arc is not generated. To ensure that the resistance in the wire is maintained at the desired level, the embodiment adjusts the voltage, current, or voltage and current.

In another exemplary embodiment of the present invention, rather than blocking the heating current when the threshold level is sensed, the power supply 170 reduces the heating current to a non-arcing level. This level is the background current level at which no arc will occur if the wire is separated from the weld paddle. For example, an exemplary embodiment of the present invention may have a non-arcing current level of 50 amps, where if an arc occurrence is sensed or predicted or an upper threshold (as described above) is reached, The power supply 170 drops the heating current from the operating level to the non-arcing level until the sensed voltage, current, power, and / or resistance falls below the upper threshold. The non-arc generation threshold may be a voltage level, a current level, a resistance level, and / or a power level. In this embodiment, it is possible to cause a faster heating current operating level recovery by maintaining the current output during arcing, even at low levels.

In another exemplary embodiment of the present invention, the output of the power supply 170 is controlled such that no substantial arcing is generated during the welding operation. In some exemplary welding operations, in an embodiment, the output of the power supply can be controlled such that no substantial arc is generated between the filler wire 140 and the puddle. It is generally known that an arc is created within the physical gap between the end of the filler wire 140 and the weld puddle. As described, exemplary embodiments of the present invention prevent arcing from being generated by keeping the filler wire 140 in contact with the puddle. However, in some exemplary embodiments, the presence of an inconsequential arc will not jeopardize the quality of the weld. That is, in some exemplary welding operations, the creation of a short-term, inconsequential arc will not result in a heat input at a level that would jeopardize the weld quality. In this embodiment, the welding system and the power supply are controlled and operated as described herein with respect to completely preventing the arc, but the power supply 170 is controlled such that the arc is not to such an extent that an arc is generated . In some exemplary embodiments, the power supply 170 operates such that the generated arc has a duration less than 10 ms. In another exemplary embodiment, the arc has a duration less than 1 ms, and in other exemplary embodiments the arc has a duration less than 300 seconds. In such an embodiment, the presence of such an arc does not jeopardize the weld quality, since the arc does not give substantial heat input to the weld or does not cause significant spatter or porosity. Thus, in this embodiment the power supply 170 is controlled such that the arc remains uninterrupted for a duration up to the extent that an arc is generated so that the weld quality is not compromised. The same control logic and elements as discussed herein with respect to other embodiments may be used in these exemplary embodiments. However, the power supply 170 may utilize the detection of arc generation for an upper limit, rather than a critical point (of current, power, voltage, resistance) below a set or predicted arc generation point. This embodiment may allow the welding operation to be made closer to this limit.

Because the filler wire 1400 is preferably in a constantly shorted state (constant contact with the welding puddle), the current tends to decay at a slow rate. This is due to the inductance present in the power supply, the welding cable and the workpiece. In some applications it may be necessary to have the current damped at a faster rate so that the current in the wire is reduced at high speed. In general, the faster the current is reduced, the better control over the bonding method will be achieved. In an exemplary embodiment of the invention, the ramp down time for current after detection of the reached or exceeded threshold is 1 millisecond. In another exemplary embodiment of the present invention, the ramp down time for current is less than or equal to 300 microseconds. In another exemplary embodiment, the ramp down time is within the range of 100 to 300 microseconds.

In an exemplary embodiment, a ramp down circuit is introduced into the power supply 170 to obtain this ramp down time, which helps to reduce the ramp down time when the arc is foreseen or detected. For example, when an arc is detected or predicted, the ramp-down circuit that introduces resistance into the circuit is opened. For example, the resistor may be in the form of reducing the current flow to less than 50 amps within 50 microseconds. A simplified example of such a circuit is shown in Fig. The circuit 1800 has a resistor 1801 and a switch 1803 located in the welding circuit such that the switch 1803 is closed when the power supply is operating and provides current. However, when the power supply stops supplying power (in order to prevent the generation of an arc or when an arc is detected), the switch forcibly opens the induced current through the resistor 1801. [ The resistor 1801 significantly increases the resistance of the circuit and reduces the current faster. These types of circuits are commonly found in the welding industry and can be found in PowerWave®, a welding power supply manufactured by Lincoln Electric Company of Cleveland, Ohio, which uses Surface-Tension-Transfer Technology ("STT") . The STT technology is generally described in U.S. Patent Nos. 4,866,247, 5,148,001, 6,051,810 and 7,109,439, which are incorporated herein by reference in their entirety. Of course, these patents generally discuss the use of the disclosed circuit to ensure that an arc is generated and maintained - one skilled in the art can readily adjust such a system to ensure that an arc is not generated.

The above description can be better understood with reference to Figure 12, in which an exemplary welding system is shown (it should be noted that the laser system is not shown for clarity). There is shown a system 1200 having a hot wire power supply 1210 (which may be similar to that shown in FIG. 1 at 70). The power supply 1210 may be a known welding power supply configuration such as an inverter type power supply. Since the design, operation, and configuration of these power supplies are known, they will not be described in detail herein. The power supply 1210 includes a user input 1220 that allows the user to input data, wherein the data may include, but is not limited to, wire feed rate, wire shape, wire diameter, desired power level, desired wire temperature, Voltage and / or current level. Of course, other input parameters may also be used as needed. The user interface 1220 is coupled to the CPU / controller 1203 which receives the user input data and uses this information to generate the required operating set point or range for the power module 1250. The power module 1250 may be any known type or configuration, including an inverter or a transformer type module.

The CPU / controller 1230 may determine the desired operating parameters in a number of ways, including using a look-up table. In this embodiment, the CPU / controller 1230 determines the desired current level and the threshold voltage or power level (or the allowable operating range of the voltage or power) for the output (to roughly heat the wire 140) For example, wire feed rate, wire diameter, and wire shape. 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, thus requiring less current / power to melt the wire 140. Additionally, a smaller diameter wire 140 will require less current / power than a wider diameter electrode. In addition, as the wire feed rate increases (and therefore the deposition rate), the current / power level required to melt the wire will be higher.

Similarly, input data may be used by the CPU / controller 1230 to determine the voltage / power threshold and / or range (e.g., power, current and / or voltage) Will be. For example, a mild steel electrode with a diameter of 0.045 inches may have a voltage range setting of 6 to 9 volts, where the power module 1250 is driven to maintain a voltage between 6 and 9 volts. In this embodiment, the current, voltage and / or power are driven to maintain a minimum value of 6 volts - which ensures that the current / power supply is high enough to adequately heat the electrode, and the voltage is 9 volts or less To ensure that an arc is not generated and that the melting temperature of the wire 140 is not exceeded. Of course, other set point parameters, such as voltage, current, power or resistivity variations, may also be set by the CPU / controller 1230, if desired.

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. Thus, the heating current is supplied to the wire 140 through the positive terminal 1221 and returned through the negative terminal 1222. Such a configuration is generally known.

Of course, in another exemplary embodiment, the cathode terminal 1222 may also be connected to the tip 160. [ Because the resistive heating may be used to heat the wire 140, the tip may be positioned such that the cathode and anode terminals 1221/1222 contact the contact tip 140 to heat the wire 140 (as shown in Figure 11) Lt; / RTI > For example, the contact tip 160 may have a dual structure (as shown in FIG. 11B) or it may use an induction coil (as shown in FIG. 11C).

Feedback sense lead 1223 is also coupled to power supply 1210. This feedback sensing lead can monitor the voltage and also delivers the sensed voltage to the voltage sensing circuit 1240. [ The voltage sensing circuit 1240 delivers the sensed voltage and / or the sensed voltage speed change to the CPU / controller 1230, which then controls the operation of the module 1250. For example, if the sensed voltage is below a desired operating range, then the CPU / controller 1230 may determine that increasing the output (current, voltage and / or power) until the sensed voltage is within the desired operating range, ). Similarly, if the sensed voltage is at or above a desired threshold, the CPU / controller 1230 directs the module 1250 to block current flow to the tip 160, thus no arc is generated. If the voltage falls below a desired threshold, the CPU / controller 1230 directs the module 1250 to supply the current or voltage or both the current and the voltage to continue the welding process. Of course, the CPU / controller 1230 may also instruct the module 1250 to maintain or supply the desired power level.

It is noted that the sensing circuit 1240 and the CPU / controller 1230 may have similar configuration and operation as the configuration and operation of the controller 195 shown in FIG. In an exemplary embodiment of the invention, the sampling / sensing rate is at least 10 KHz. In another exemplary embodiment, the sensing / sampling rate is in the range of at least 100 to 200 KHz.

13A-C illustrate exemplary current waveforms and voltage waveforms used in embodiments of the present invention. Each of these waveforms will be discussed in turn. 13A shows voltage waveforms and current waveforms for an embodiment in which the filler wire 140 touches the weld puddle after the power supply output has started-after arc sensing. As shown, the output voltage of the power supply was less than the threshold (9 volts) determined at some operating level and then increased to this threshold during welding. The operating level may be a determined level based on various input variables (discussed previously) and may be a set operating voltage, current, and / or power level. This operating level is the desired output of the power supply 170 for a given welding operation and is intended to provide the desired heating signal to the filler wire 140. During welding, it may occur that the arc can be generated. In Fig. 13A, this case causes an increase in voltage and increases the voltage to point A. Fig. At point A, the power supply / control circuit reaches a 9 volt threshold (which may be an arc detection point or a simple predetermined upper threshold and may be below the arc generation point) and turns off the output of the power supply to turn off the current and voltage Lt; RTI ID = 0.0 > B < / RTI > The slope of the current drop can be controlled by the inclusion of a ramp-down circuit (such as discussed herein) that helps to drastically reduce the current generated from the system inductance. The current or voltage level at point B may be predetermined or may be reached after a predetermined duration. For example, in some embodiments, an upper limit threshold for voltage (or current or power) as well as a lower limit non-arcing level is set for welding. This lower limit level may be a lower voltage, current, or power level that is guaranteed that an arc can not be generated so that returning to the power supply is acceptable and no arc will be generated. Having this lower limit level allows the power supply to quickly come back and allows to ensure that an arc is not generated. For example, if the power supply setpoint for the weld is set at 2,000 watts with a voltage threshold of 11 volts, this lower power setting can be set at 500 watts. Thus, when the upper voltage threshold (which may be a current or power threshold according to the embodiment) is reached, the output is reduced to 500 watts (this lower threshold may also be a lower current, voltage setting, or current and voltage setting). Alternatively, rather than setting the lower limit sensing limit, a timing circuit may be used to start the current supply after a set duration. In an exemplary embodiment of the invention, this duration may be in the range of 500 to 1000 milliseconds. In Fig. 13A, point C represents the time at which the output is fed back to the wire 140. It is noted that the delay shown between point B and point C may be the result of an intentional delay or simply a result of a system delay. At point C the current is fed back to the filler wire. However, since the filler wire does not touch the weld puddle yet, the voltage increases while the current does not increase. At point D, the wire contacts the puddle and the voltage and current return to the desired operating level to stabilize. As shown, the voltage before contact at point D may exceed the upper threshold, which may occur when the power supply has an OCV level higher than the level of the operating threshold. For example, a higher OCV level may be an upper limit setting in a power supply as a result of design or manufacture.

13B is similar to that described above except that the filler wire 140 is in contact with the weld puddle when the power supply's output is increased. In this situation, prior to point C, the wire never left the weld puddle and the wire also contacted the weld puddle. Figure 13b shows point C and point D together because the wire is in contact with the puddle when the output turns on again. Thus, the current and voltage increase to the desired operating setting at point E.

13C shows an embodiment in which the wire contacts the puddle for some time before point B with little or no delay between the turned off output (point A) and the again turned on output (point B). The waveform shown can be used in the embodiment described above in which the lower limit threshold is set so that when the lower limit threshold is reached, whether it is current, power or voltage, the output is turned on again with little or no delay. It is noted that this lower threshold setting may be set using parameters that are the same or similar to the operating upper threshold or range described herein. For example, the lower threshold may be set based on the wire component, diameter, feed rate, or various other parameters described herein. This embodiment can minimize the delay in returning to the operating set point for the desired weld and minimize any necking that can occur in the wire. Minimizing the necking helps to minimize the chance that an arc is created.

Figure 14 shows another exemplary embodiment of the present invention. Fig. 14 shows an embodiment similar to the embodiment shown in Fig. However, for clarity, certain elements and connections are not shown. 14 illustrates a system 1400 in which a thermal sensor 1410 is used to monitor the temperature of wire 140. [ The thermal sensor 1410 may be of any known type capable of sensing 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 sense the temperature of the wire. In another exemplary embodiment of the present invention, the sensor 1410 is in the form of a laser or infrared beam that is capable of sensing the temperature of a small object, such as the diameter of a filler wire, without contacting the wire 140. In this embodiment, the sensor 1410 is positioned such that the temperature of the wire 140 can be sensed at the protrusion of the wire 140, which is some point between the tip 160 and the weld puddle. The sensor 1410 should also be positioned so that the sensor 1410 for the wire 140 does not sense the welding puddle temperature.

Sensor 1410 is coupled to sensing and control unit 195 (discussed in conjunction with FIG. 1) to provide temperature feedback information to power supply 170 and / or laser power supply < RTI ID = 0.0 > (Not shown). For example, the power or current output of power supply 170 may be adjusted based at least on feedback from sensor 1410. [ That is, in an embodiment of the present invention, a user may enter a desired temperature setting [for a given weld and / or wire 140], or the sensing and control unit may input other user input data (wire feed rate, ), And then the sensing and control unit 195 controls at least the power supply 170 to maintain the desired temperature.

In this embodiment, heating of the wire 140 that may occur due to the laser beam 110 affecting the wire 140 before the wire enters the welding puddle may be accounted for. In an embodiment of the present invention, the temperature of the wire 140 can be controlled only through the power supply 170 by controlling the current in the wire 140. However, in other embodiments, heating of at least a portion of the wire 140 may occur in the laser beam 110 that affects at least a portion of the wire 140. In this way, only the current or power from the power supply 170 can not represent the temperature of the wire 140. Thus, the use of the sensor 1410 can help control the temperature of the wire 140 through the 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 is intended to sense the temperature of the welding puddle. In this embodiment, the temperature sensor of the welding pudes is also coupled to the sensing and control unit 195. However, in another exemplary embodiment, the sensor 1420 is directly coupled to the laser power supply 130. Feedback from the sensor 1420 is used to control the output from the laser power supply 130 / laser device 120. That is, the energy density of the laser beam 110 may be modified to ensure that the desired welding puddle temperature is achieved.

In another exemplary embodiment of the present invention, rather than having the sensor 1420 direct the puddle, it may direct an area of the workpiece adjacent to the weld puddle. In particular, it may be desirable to ensure that the heat input to the workpiece adjacent to the weld is minimized. The sensor 1420 can be positioned to monitor this temperature sensitive area so that the critical temperature of the region adjacent to the weld is not exceeded. For example, the sensor 1420 can monitor the workpiece temperature and reduce the energy density of the beam 110 based on the sensed temperature. This configuration will ensure that the heat input adjacent to the weld bead does not exceed the desired threshold. This embodiment can be used for precise welding operations in which heat input into the workpiece is important.

In another exemplary embodiment of the present invention, sensing and control unit 195 may be coupled to a supply force sensing unit (not shown) coupled to a wire supply mechanism (not shown, but 150 in FIG. 1). The supply force sensing unit is known and detects the supply force being applied to the wire 140 as the wire 140 is being supplied to the workpiece 115. [ For example, this sensing unit may monitor the torque being applied by the wire feed motor in the wire feeder 150. If the wire 140 passes through the molten weld puddle without complete melting, the wire will contact the solid portion of the workpiece, and such contact will cause the feed force to increase as the motor attempts to maintain the set feed rate will be. This increase in force / torque can be sensed and transmitted to sensing and control unit 195. Here, the control unit uses this information to adjust the voltage, current, and / or power to the wire 140 to ensure proper melting of the wire 140 within the puddle.

It is noted that in some exemplary embodiments of the present invention, the wire is not constantly fed into the welding puddle but may be made intermittently based on the desired weld profile. In particular, the flexibility of the various embodiments of the present invention enables the operator or control unit 195 to start and stop feeding the wire 140 into the puddle as desired. For example, some parts of the weld joint that require the use of a filler material (wire 140) and many other types of parts that may have other parts on the same workpiece that do not require the use of the same joint or filler material There is a complex weld profile and geometric structure. As such, the control unit 195 may only actuate the laser device 120 to cause laser welding of this first portion of the joint during the first portion of the weld, but the welding operation requires the use of a-filler metal When reaching the second portion of the weld joint, the controller 195 causes the power supply 170 and the wire feeder 150 to begin welding the wire 140 into the weld puddle. Thereafter, as the welding operation reaches the end of the second portion, the welding of the wire 140 can be stopped. This allows for the creation of successive welds with profiles that differ significantly from one part of the following puddles. In contrast to having many separate welding operations, this capability allows the workpiece to be welded in a single welding operation. Of course, various modifications can be made. For example, the welds may have three or more distinct portions that require a weld profile with varying shape, depth, and filler requirements, so the use of the laser and wire 140 may be different at each weld. In addition, additional wires may be added or removed as needed. That is, the first weld 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 weld requires the use of two or more filler wires . In order to achieve this changing welding profile in a continuous welding operation, the controller 195 can be configured to control various system components to produce continuous weld beads in a single welding pass.

Figure 15 illustrates a typical welding puddle P during welding according to an exemplary embodiment of the present invention. As previously described, the laser beam 110 creates puddles P in the surface of the workpiece W. [ The weld pudes have a length L that is a function of the energy density, shape, and movement of the beam 110. In an exemplary embodiment of the present invention, beam 110 is directed at puddle P at a distance Z from the trailing edge of the weld puddle. In this embodiment, the high-intensity energy source (e.g., laser device 120) does not cause its energy to directly affect the filler wire 140 such that the energy source 120 does not melt the wire 140 , But rather the wire 140 completes its melting due to contact with the welding puddle. The trailing edge of the puddle P is generally defined as the point at which the molten puddle termination and the resulting weld bead WB begin to solidify. In an embodiment of the present invention, the distance Z is 50% of the length L of the puddle P. In another exemplary embodiment, the distance Z is in the range of 40 to 75% of the length L of the puddle P. [

As shown in FIG. 15, the filler wire 140 impacts the puddle P behind the beam 110 - in the direction of travel of the weld. As shown, the wire 140 impacts the puddle P in front of the trailing edge of the puddle P by the distance X. As shown in Fig. In an exemplary embodiment, the distance X is in the range of 20 to 60% of the length of the puddle P. In another exemplary embodiment, the distance X is in the range of 30 to 45% of the length of the puddle P. In another exemplary embodiment, the wire 140 and the beam 110 are configured to cause at least a portion of the beam 110 to affect the wire 140 during the welding process, either at the surface of the puddle P, It goes crazy. In this embodiment, a laser beam 110 is used to assist in melting the wire 140 for deposition in the puddle (P). If the wire 140 is too cold to quickly dissipate in the puddle P, then using the beam 110 to assist in melting the wire 140 may cause the wire 140 to quench the puddle P It helps to prevent. However, as previously described, in some exemplary embodiments (as shown in FIG. 15), as the melting of heat by the heat of the welding puders is completed, the energy source 120 and the beam 110 are separated from the filler wire 140 ≪ / RTI > does not noticeably melt.

In the embodiment shown in FIG. 15, the wire 140 follows the beam 110 and is in line with the beam 110. However, the present invention is not limited to such a configuration as the wire 140 may advance (in the moving direction). Moreover, it is not necessary to have the wire 140 in line with the beam in the direction of movement, but as long as the appropriate wire melting occurs within the puddle, the wire can affect the puddle from any direction.

16A-16F show various puddles P with the footprint of the laser beam 110 shown. As shown, in some exemplary embodiments, the puddle P has a circular footprint. However, the embodiment of the present invention is not limited to this configuration. For example, it is contemplated that the puddles may have an elliptical or other shape.

16A-16F also show a beam 110 having a circular cross-section. Again, other embodiments of the present invention are not limited in this regard as the beam 110 may have an oval, square, or other shape to effectively create the weld puddle (P).

In some embodiments, the laser beam 110 may remain stationary with respect to the weld puddle (P). That is, the beam 110 remains in a relatively coherent position relative to the puddle P during welding. However, as is simplified in Figs. 16A-16, other embodiments are not limited in this manner. For example, FIG. 16A illustrates an embodiment in which the beam 110 is delivered in a circular pattern around the puddle P. In this figure, the beam 110 is transmitted such that at least one point on the beam 110 is always superimposed on the center C of the puddles. In another embodiment, a circular pattern is used, but the beam 110 is not in contact with the center C. 16B shows an embodiment in which the beam is transmitted back and forth along a single line. This embodiment can be used to lengthen and widen the puddle P according to the desired puddle (P) shape. Figure 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. This embodiment is used to maintain the wider puddle size while increasing the penetration at the point in the puddle P if necessary. This embodiment may be achieved with a single laser device 120 by varying the beam shape through use of a laser lens and an optical element or may be accomplished through the use of multiple laser devices 120 have. 16D shows the beam 110 delivered in an elliptical pattern in the puddle (P). Again, this pattern can be used to lengthen or widen the welding puddles P as needed. Another beam 110 transfer may be used to generate the puddle (P).

16E and 16F show cross sections of the workpiece W and puddle P using different beam intensities. Figure 16e shows the shallow wider puddles P produced by the wire beam 110, while Figure 16f shows deeper and narrower weld puddles P - typically referred to as "keyholes" . In this embodiment, the beam is focused and its focus is near the upper surface of the workpiece W. [ With this focus the beam 110 can penetrate through the entire depth of the workpiece and help create a back bead on the bottom surface of the workpiece W. [ The beam intensity and shape are determined based on the desired characteristics of the weld puddles during welding.

The laser device 120 may be moved, transferred, or actuated by any other known method and apparatus. Since the movement of the laser and the optical elements are generally known, they will not be described in detail herein. Figure 17 illustrates a system 1700 in accordance with an exemplary embodiment of the present invention, wherein the laser device 120 may have optical elements (such as lenses) that can be moved and changed or adjusted during operation. The system 1700 couples the sensing and control unit 195 to the motor 170 and the optical drive unit 1720. The motor 170 moves or transfers the laser to move the position of the beam 110 relative to the welding puddle during welding. For example, the motor 1710 can transfer the beam 110 back and forth, and can move the beam in a circular pattern or the like. Similarly, the optical drive unit 1720 receives an indication from the sensing and control unit 195 to control the optical elements of the laser device 120. [ For example, the optical drive unit 1720 causes the focus of the beam 110 to move or change relative to the surface of the workpiece, thus changing the penetration or depth of the weld paddle. Similarly, the optical drive unit 1720 causes the optical elements of the laser device 120 to change the shape of the beam 110. As such, during welding, the sensing and control unit 195 controls the laser device 120 and the beam 110 to maintain and / or deform the characteristics of the welding puddle during operation.

As discussed above with reference to Figure 7b, hot wire laser welding consistent with the present invention allows narrow gap welding, which was difficult only with an arc or laser welding process. In addition to the advantages discussed above, hot wire laser welding of the present invention allows for welding of thin wall workpieces, for example less than 10 mm, which would not have been possible with typical arc welding processes. This is especially true when the depth of the weld is longer than the depth of the material. For example, as shown in Fig. 20A, the joint depth is longer than the thickness of each workpiece 115A / 115B. That is, in an exemplary embodiment of the invention, the joint depth or weld bead depth is deeper (in the length dimension) than the thickness of at least one workpiece, and in another embodiment the bead is deeper than the thickness of both workpieces. However, arc processes such as GMAW tend to have wider weld puddles and higher heat input that can distort the workpiece due to the excessive filler material required in such processes. This is because the arc process requires a wide gap in order to provide shielding gas as discussed above and to prevent the iron containing sidewalls of the weld groove from interfering with the arc. The heat input required to melt the excess filler material can distort thin workpieces.

Attempts to narrow the joint gap can cause other problems in the arc welding process. For example, in an arc-type process, as shown in FIG. 20A, the weld pawls can connect the joint without being deeply penetrated, which can cause a stress riser in the finished joint. Further, as shown in Fig. 20A, when joining the thin wall workpieces 115A and 115B, the arc-type process can have a wide welding cap, which makes it difficult to determine the depth of the weld have. Typically, the visible thermal lines 116 on the workpiece 115B provide an indication of the depth of penetration of the weld paws, i.e., an indication of the bottom of the weld joint. However, a wide welding cap in a typical arc welding process, such as a GMAW process, will cover the outer edge of a thin workpiece, such as workpiece 115B. The upper outer edge of the workpiece corresponds to the upper end of the weld joint. Without knowing where the upper outer edge of the workpiece 115B (i.e., the upper end of the weld joint) is, it will be difficult to know the penetration depth.

While the above drawbacks with respect to heat input and weld cap dimensions can be controlled in the laser welding process, the laser process has other problems. For example, in a laser welding process, the laser is more focused than in a cladding process to provide strength for melting the workpiece and for forming weld puddles. However, the workpiece typically has to be very tightly fitted, e.g. with a gap smaller than a 1 mm gap. Otherwise, the laser will be fired through the gap in the joint and / or the weld pads formed by the laser will not be able to cover the gap.

As shown in Fig. 20B, the hot wire laser welding process consistent with the present invention can overcome the disadvantages discussed above. Also, since this is a hot wire laser process, there is little or no spatters associated with the process and no shielding gas is required. The structure and control of the laser device and the hot wire will be similar to that shown in FIG. 7B with respect to the laser device 120 and the hot wire 140. The structure and control of the hot wire laser system is therefore not discussed further. Returning to Fig. 20B, the workpieces 115A and 115B are arranged with a narrow gap GP. The gap GP depends on the ability of the weld beads to be formed by the melting of the workpieces 115A and 115B and the hot filler wire 140. [ However, it is contemplated that the gap GP will have an average gap width in the range of one to three times the diameter of the wire 140. [ In another exemplary embodiment, the gap width will be in the range of one to two times the diameter of the wire 140. Generally, the average gap width refers to the average distance between the sidewalls of the joint with respect to the depth of the joint. In an exemplary embodiment of the present invention, the laser device 120 and the hot wire 140 will produce welding puffs that are about twice the diameter of the hot wire 140. Also, because of the characteristics of the embodiments of the present invention (discussed above), the process of the present invention may have a penetration depth in the range of 4 to 10 times the diameter of the hot wire 140, while other exemplary embodiments of the present invention In the example, the penetration depth may be in the range of 6 to 10 times the diameter of the hot wire 140. It should be noted that although the above description refers to "penetration" depth, it is also understood to include buildup depth.

For example, as shown in FIG. 20A, the presence of a gap between the workpieces does not require the laser to penetrate the entire depth of the workpiece, and instead builds up the weld bead within the joint gap as shown . Because some embodiments will build up the joints, less laser energy will be needed than using a laser to keyhole the workpiece, as opposed to completely penetrating the workpiece. Moreover, the thickness of the workpiece can be relatively thin due to the advantages of the embodiment of the present invention. For example, as shown in FIG. 20B, without causing notable distortion, the workpieces 115A and 115B may have a thickness in the range of 4 to 15 mm in the welded joint, and in some embodiments 4 to 10 mm It can be in range. This thickness will be the average thickness of the workpiece (s) in the weld joint with respect to the depth of the weld joint and may or may not be the thickness of the entire length of the weld joint. Thus, an exemplary embodiment of the present invention can provide a weld joint with a very narrow gap width but deep penetration, which can not be achieved through a typical welding operation.

As shown in FIG. 20B, the hot wire laser process described above produces weld penetration that penetrates well into the root of the joint using less filler material and heat input than conventional arc welding processes, and forms a strong joint. In addition, penetration rate and wire feed rate are comparable to typical arc welding processes. For example, it is expected that a traveling speed greater than 100 imp (inches per minute) and a wire feed speed greater than 400 imp can be achieved based on the welding parameters. It is also easier to inspect the welded portion since the welding cap does not cover the upper edge of the thin wall workpiece 115B as in the arc type process. Since the upper outer edge of the workpiece 115B is visible, the distance between the upper end (upper edge) of the joint and the bottom of the joint (column line 116) can be easily measured.

In each of Figures 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 elements can be made integral with a single welding system. Aspects of the present invention do not require that the above discussed individually discussed elements be maintained as separate physical units or as stand alone structures.

While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention . Various modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope of the invention. It is therefore intended that the invention not be limited to the particular embodiment disclosed, and that the invention will include all embodiments falling within the scope of the appended claims.

240: Step 250:
100: system 260: step
110: laser beam 310: step
110A: laser beam 320:
115: workpiece 330: step
115A: workpiece 340: step
115B: workpiece 350: step
116: heating line 410: current waveform
120: laser device 411:
120A: laser device 412: point
121: beam splitter 420: current waveform
125: direction 425: lamp
130: Power supply unit 430: Spacing
140: filler wire 440: set point value
150: filler wire feeder 450: output current level
160: contact tube 510: current waveform
170: Power supply unit 511:
180: Motion controller 512: Point
190: robot 520: current waveform
195: current control subsystem 525: heating current level
200: start method 530: interval
220: Step 601: Lap joint surface
230: Step 601A:
603: Lap joint surface 1230 CPU / controller
603A: melted puddle 1240: voltage sensing circuit
605: Surface 1250: Power module
701: inclined surface 1400: system
703: inclined surface 1410: sensor
705: gap 1420: sensor
707: Weld bead 1700: System
801: welding puddle 1710: motor
803: welding puddle 1720: optical drive unit
901: Welding puddle 1800: Circuit
903: welding puddle 1801: register
1000: Welded joint 1803: Switch
1010: Laser source 1901: Laser shroud system
1011: Beam 1903: Fume extraction system
1012: welding puddle A: point
1020: laser source B: point
1021: laser beam BB: back bead
1022: welding puddle C: point / center
1030: Filler wire D: point
1030A: Filler wire E: Point
1110: Coil L: Length
1200: System P: Puddle
1210: Power supply unit WB: Weld bead
1220: User input part X: Distance
1222: Negative terminal Z: Distance
1223: Sense lead

Claims (15)

Creating weld fur within the open root weld joint with at least one high intensity laser energy source;
Heating the at least one filler wire with a wire heating signal from the power source to a temperature at which the filler wire melts in the weld puddle when the filler wire contacts the melt puddle;
Directing the filler wire to the weld puddle so that the filler wire maintains contact with the weld puddle during the welding operation;
Monitoring feedback from the filler wire heating signal;
Interrupting the filler wire heating signal when an upper threshold is reached by feedback to prevent arcing between the filler wire and the weld puddle; And
Turning on the filler wire heating signal to continue heating the filler wire
Wherein the open root welded joint is produced by at least two workpieces having an average gap in the range of one to three times the diameter of the filler wire and the depth of the open root welded joint is less than the diameter of the filler wire Of the total length of the weld zone. The welding method according to claim 1, wherein the depth of the open root weld joint is in the range of 6 to 10 times the diameter of the filler wire. The welding method according to claim 1 or 2, wherein the average gap is in the range of 1 to 2 times the diameter of the filler wire. The welding method according to one of claims 1 to 3, wherein the thickness of at least one of the workpieces in the open root welded joint is in the range of 4 to 15 mm. The welding method according to one of claims 1 to 4, wherein the traveling speed of the welding is at least 100 ipm (inch per minute). 6. A welding method according to any one of claims 1 to 5, wherein the wire heating signal heats the filler wire to its melting temperature or to 90% or more of the melting temperature. 7. A welding method according to any one of claims 1 to 6, wherein the threshold value is a voltage threshold value. 8. A method according to any one of claims 1 to 7, wherein the threshold voltage value is 16 volts or less. The welding method according to one of claims 1 to 8, wherein the at least one high-strength energy source is a laser. At least one high-strength energy source for directing high-intensity energy to a plurality of workpieces (115, 115A, 115B, W) to create weld puddles (P) within an open-root weld joint;
At least one filler wire 140 is arranged to heat the filler wire 140 to a temperature at which the filler wire 140 is melted in the weld puddle P when the filler wire 140 contacts the melt puddle P, A heating power supply for providing a wire heating signal to the heating element; And
A wire feed mechanism 150 that advances the filler wire 140 to the weld puddle P so that the filler wire 140 remains in contact with the weld puddle P during the welding operation,
≪ / RTI >
The heating power source monitors the feedback from the filler wire 140 heating signal and cuts off the heating signal of the filler wire 140 when the upper threshold is reached by the feedback so that it is between the filler wire 140 and the welding puddle P No arc is generated where the heating power supply turns on the filler wire 140 heating signal to continue heating the filler wire 140,
The open root weld joint is created by at least two workpieces (115, 15A, 115B, W) with an average gap in the range of one to three times the diameter of the filler wire (140) Wherein the depth of the joint is in the range of 4 to 10 times the diameter of the filler wire (140). 11. The method of claim 10 wherein the depth of the open root weld joint is in the range of six to ten times the diameter of the filler wire (140) and / or the average gap (705) is one to two times the diameter of the filler wire (100, 1200, 1400, 1700). ≪ / RTI > The welding system according to claim 10 or 11, wherein the thickness of at least one of the workpieces (115, 115A, 115B, W) in the open root weld joint is in the range of 4 to 15 mm. , 1400, 1700). The welding system (100, 1200, 1400, 1700) according to one of the claims 10 to 12, wherein the running speed of the welding is at least 100 ipm. 11. The welding system (100, 1200, 1400, 1700) of claim 10, wherein the wire heating signal heats the filler wire (1400) to at least 90% of its melting temperature or its melting temperature. 15. A welding system (100, 1200, 1400, 1700) according to one of claims 10 to 14, wherein the threshold is a voltage threshold and / or the threshold voltage is 16 volts or less.

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