Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K9/00—Arc welding or cutting
  • B23K9/12—Automatic feeding or moving of electrodes or work for spot or seam welding or cutting
  • B23K9/124—Circuits or methods for feeding welding wire

Definitions

• the invention relates to a cold metal transfer welding method, hereinafter referred to as CMT process, in which the welding process is defined by cyclic alternation of an arc phase and a short circuit phase, wherein during a arc phase, a welding wire until it contacts the workpiece in the direction Workpiece is moved, then after formation of a short circuit during the short phase, the wire feed is reversed and the welding wire is moved away from the workpiece, the welding current and / or the welding voltage is controlled during the arc phase such that the welding wire is melted and a drop is formed, and that during the short-circuit phase, an opening of the short circuit is prevented via the welding current, whereby welding parameters are set in order to determine the welding process.
• CMT process cold metal transfer welding method, hereinafter referred to as CMT process, in which the welding process is defined by cyclic alternation of an arc phase and a short circuit phase, wherein during a arc phase, a welding wire until it contacts the workpiece in the direction Workpiece is moved, then after formation of
• the welding wire is moved away from the workpiece until the short circuit is opened and / or a defined distance from the workpiece and / or over a defined period of time.
• the invention relates to a welding system with a welding device, at least one control device with a memory for operating data or programs, a power source, a wire feeder for conveying a welding wire, a connectable to the welding torch and a input and / or output device with at least two control elements for Setting welding parameters.
• a method for controlling a welding power source in which the waveform of the welding current has at least one arc component and one short-circuit component.
• a short-circuiting phase is initiated by movement of the welding wire to the contact of the workpiece and an arc phase initiated by the return movement of the welding wire.
• the short circuit portion of the welding current is applied during the short circuit phase before the welding wire is lifted off the workpiece to form an arc.
• the short-circuit portion has the Peak current in a period of the welding current, so that in the short-circuit phase, a high current flows over the welding wire and the workpiece.
• the lower amount of arc portion of the welding current is applied when moving back the welding wire to form the arc.
• the waveform of the welding current and the return movement of the welding wire which have several different phases, are coordinated accordingly.
• a disadvantage is that the duration of the arc phase and the short-circuit phase, which alternate periodically, not directly on the welding machine, but only indirectly via welding parameters such as welding current, wire feed speed, etc. can be set.
• US 2002/0153363 A1 describes a welding method in which the melting rate of the welding wire can be controlled.
• the definition of the welding process requires, as in other welding processes of the prior art, the setting of a large number of welding parameters on the welding machine and thus the corresponding knowledge of the welder.
• the object of the present invention is to provide an above-mentioned welding method and a welding system, with which the complex interaction of the individual welding parameters for optimum welding results and optimum quality of the weld can be used with the lowest possible number of settings on the welding machine. Regardless of the process conditions, consistent results are to be achieved.
• the object of the invention is achieved in terms of the method in that as a welding parameter via a control member a movement frequency of the welding wire, with which the number of arc phases and short circuit phases per second is defined and at least one further welding parameters are set, and determined by a control device all other required welding parameters to achieve the predetermined movement frequency and adjusted and regulated.
• the movement frequency thus specifies the number of periods, which are each formed by an arc phase and a short-circuit phase, per second.
• the user adjusts this movement frequency and at least one further welding parameter, whereupon, from this information, the control device automatically determines and adjusts and regulates all further required welding parameters, such as welding current and wire feed speed, so that the set movement frequency is maintained during the welding process. No special welding skills are required for the user.
• the diameter of the welding wire or the melting rate can be adjusted.
• the welding wire welding parameters such as the welding current and / or the wire feed speed, regulated such that at constant wire feed speed, a constant distance of the welding wire to the workpiece, which the length of the arc between the welding wire and the workpiece corresponds to be achieved.
• the short-circuit phase can be deliberately initiated and thus spatter can be avoided.
• the arc pressure is reduced, whereby upon contact of the welding wire with the workpiece, no dropping of the droplet of liquefied material can occur and thus a continuous transition is achieved.
• the wire feed speed is increased to reduce the length of the arc between the welding wire and the workpiece to short circuit, the short circuit can be reached faster and thereby the duration of Short circuit formation can be reduced. As a result, the time duration for the arc phase can be increased and thus more filler material can be melted.
• the length of the arc between the welding wire and the workpiece during the arc phase is monitored and changes in the arc length are controlled via the welding parameters, in particular the wire feed speed and the welding current such that the short-circuit phase with the set movement frequency occurs, can interfere with the workpiece surface, such as depressions or increases, are detected and compensated, and early initiation of the short-circuit phase avoided.
• the welding parameters can be controlled to vary the duration of the short-circuit phase, so that the subsequent arc phase occurs at the set movement frequency.
• the temperature of the molten bath and thereby the penetration can be regulated in an advantageous manner.
• the heat input into the workpiece is set, and the ratio of the duration of the short-circuit phase to the duration of the arc phase and / or a profile of the welding current determined as a function of the set heat input, for example, the delay of the material, which depends on the heat input, reduced become. Furthermore, the temperature of the molten bath and the penetration can be adjusted.
• the movement frequency is set between 1 Hz and 150 Hz, preferably between 30 Hz and 70 Hz. This achieves a particularly user-friendly handling. The user can quickly find out, for example, with the aid of tables, the optimum movement frequency for the respective workpiece to be processed. The movement frequency can also influence the appearance of the weld.
• the frequency of the molten bath oscillation can be influenced in a targeted manner via the movement frequency of the welding wire.
• a low frequency of movement By selecting a low frequency of movement, the natural vibration of the molten bath can be greatly reduced in a simple manner, whereby spatter can be avoided.
• the natural oscillation of the molten bath can be increased and, as a result, gap bridging can be improved in an advantageous manner.
• a targeted excitation of the oscillation of the molten bath can be forced.
• the welding parameters are determined and set and regulated as a function of a defined profile of the length of the arc or of the welding voltage.
• the object of the invention is also achieved by an above said welding system, wherein at the input and / or output device, a control member for setting a movement frequency, with which the number of arc phases and short circuit phases per second is defined, and the control device for performing a cold metal transfer welding method after one of the above features is formed.
• the control unit for setting the movement frequency for the CMT process can automatically determine and adjust many of the remaining, required welding parameters.
• the control member for adjusting the movement frequency may be formed as a knob.
• a scale ranging from 1 to 150 Hz scale can be arranged, whereby in a simple way, the adjustment is made possible or changes can be made.
• a control member may also be configured to adjust the material and the material thickness as a rotary knob, possibly with an arranged next to or on the knob and the material and the material thickness associated scale.
• two welding parameters are adjusted by means of a position of the rotary knob.
• At the input and / or output device may also be arranged a control member for setting a value for the heat input into the workpiece, whereby the heat input into the workpiece and the associated temperature of the molten bath can be adjusted in a simple manner.
• the control member for setting the value for the heat input into the workpiece can be configured as a rotary knob, possibly with a arranged next to or on the knob and the heat input associated scale, which ranges for example from 1 to 100.
• At least one control can also be indicated by a display with a Input field, in particular a touch screen to be formed.
• the control member for setting the movement frequency, at least one further welding parameter and the value for the heat input is completely or partially software-based, and / or with graphics support, formed via an input field. As a result, an exact value for the corresponding welding parameter can also be set.
• a remote vane for adjusting the welding parameters, in particular the movement frequency, and the value for the heat input, at the welding torch is arranged.
• the corresponding welding parameters can also be changed during the welding process.
• FIG. 1 shows an exemplary representation of a welding device
• FIGS. 2 to 7 show the time profiles of the welding voltage, the welding current and the wire feed speed and a movement diagram for the welding wire while observing a specific frequency of movement using various examples of welding methods according to the invention
• FIG. 12 and 13 embodiments of an input and / or output device of a welding system according to the invention.
• a welding apparatus 1 for a variety of processes or processes, such as MIG / MAG welding or TIG / TIG welding or electrode welding process, double wire / tandem welding process, plasma or soldering, etc., is shown.
• the welding device 1 comprises a current source 2 with a power part 3, a control device 4 and a switching element 5 assigned to the power part 3 or the control device 4.
• the switching element 5 or the control device 4 is connected to a control valve 6 which is located in a supply line 7 for a gas 8, in particular a protective gas, such as CO 2 , helium or argon and the like., Between a gas storage 9 and a welding torch 10 and a burner is arranged.
• a wire feed device 11 which is customary for MIG / MAG welding, are controlled, via a supply line 12, a filler material or a welding wire 13 from a storage drum 14 and a wire reel in the region of the welding torch 10 is supplied.
• the wire feeder 11 as is known from the prior art, is integrated in the welding device 1, in particular in the base housing, and not, as shown in Fig. 1, is designed as an accessory.
• the wire feeder 11 may supply the welding wire 13 or the additional material outside the welding torch 10 to the processing station, wherein a non-consumable electrode is preferably arranged in the welding torch 10, as is customary in TIG / TIG welding.
• the current for building up an arc 15, in particular a working arc, between the non-consumable electrode, not shown, and a workpiece 16 is supplied via a welding line 17 from the power section 3 of the power source 2 to the welding torch 10, in particular the electrode, wherein the to be welded Workpiece 16, which is formed of several parts, via a further welding line 18 also with the welding apparatus 1, in particular with the power source 2, is connected and thus can be constructed via the arc 15 and the plasma jet formed for a process, a circuit.
• the welding torch 10 can be connected via a cooling circuit 20 to a liquid container, in particular a water tank 21, whereby during commissioning of the welding torch 10 the cooling circuit 19, in particular a liquid arranged in the water tank 21 used liquid pump is started, and thus a cooling of the welding torch 10 can be effected.
• the welding device 1 further has an input and / or output device 22, via which the most varied welding parameters, operating modes or welding programs of the welding device 1 can be set or called up.
• the welding parameters, operating modes or welding programs set via the input and / or output device 22 are forwarded to the control device 4 and from this the individual components of the welding system or the welding device 1 are subsequently controlled or corresponding setpoint values for regulation or control are specified.
• the welding torch 10 is connected via a hose package 23 to the welding device 1 or the welding system.
• the individual lines from the welding device 1 to the welding torch 10 are arranged.
• the hose package 23 is connected via a coupling device 24 to the welding torch 10, whereas the individual lines in the hose package 23 are connected to the individual contacts of the welding device 1 via connection sockets or plug connections. So that a corresponding strain relief of the hose assembly 23 is ensured, the hose package 23 is connected via a strain relief device 25 with a housing 26, in particular with the base housing of the welding device 1.
• the coupling device 24 can also be used for the connection to the welding device 1.
• the welding torch 10 can be designed as an air-cooled welding torch 10.
• FIG. 2 shows an exemplary embodiment of a welding process according to the invention with reference to the diagrams 27 to 30, which schematically show the time profiles of the welding voltage U, the welding current I, the wire feed speed V and the movements or positions of the exit-side end of the welding wire 13 relative to the workpiece 16.
• a consumable electrode or a welding wire 13 is used.
• the ignition of the arc 15 can be effected by any desired method, for example in the manner of the "lift-arc principle" known from the prior art, in which an open circuit voltage is applied to the welding wire 13 during an ignition phase 31. Subsequently, the welding wire 13 becomes until the contacting of the workpiece 16 in the direction of the workpiece 16, whereupon the resulting short circuit is broken in a short-circuit phase by reversing the conveying direction of the welding wire 13.
• the Domündung of the arc 15 can in the so-called High-frequency ignition also via a high-frequency voltage signal (not shown).
• a first short stabilization phase 34 with increased heat input (as shown by dashed lines) over a defined period of time and then constructed by cyclically recurring welding process phases welding process is performed.
• This has the advantage that a stabilization of the arc 15 and / or a heating of the workpiece 16 or molten bath is provided by this short stabilization phase 34 with high heat input.
• the welding wire 13 is heated by the stabilizing phase 34, and thereby the subsequent welding process can begin with preheated welding wire 13, thereby substantially improving the welding quality.
• the actual welding process according to the invention, a cold-metal transfer welding process, hereinafter referred to as CMT process is performed.
• CMT process the welding wire 13 is conveyed in the process phase referred to herein as the arc phase 36 until it contacts the workpiece 16.
• the welding wire 13 melts, so that droplet formation, that is to say a drop 37, occurs at the end of the welding wire.
• the welding current and / or the welding voltage in the arc phase 36 is controlled such that no droplet detachment takes place and at the time 38 a short circuit occurs, which initiates the short-circuit phase 39.
• the wire feed is reversed, so that the welding wire 13 until the opening of the short circuit, ie the formation of the arc 15, and / or the defined distance 33 and / or a defined period of time from the workpiece 16 is fed back.
• the arc phase 36 occurs again at the time 35, whereupon the direction of movement of the welding wire 13 at a top dead center 32 is again reversed and the welding wire 13 is moved in the direction of the workpiece 16.
• the welding wire 13 thus performs an alternating movement in the direction of the workpiece 16 and away from the workpiece 16 during the welding process.
• the wire feeder 11 is substantially controlled so that a negative signal or a backward conveying of the welding wire 13 during the short-circuit phase 39, and then an arc 15 is established, and a positive signal or a forward conveying of the welding wire 13 in the direction of the workpiece 16 takes place during the arc phase 36, in which the heating or melting of the welding wire 13 takes place for droplet formation.
• the control of the direction of movement of the welding wire 13, however, does not necessarily correlate with the occurrence of the arc phase 36 or the short-circuit phase 39, since the arc phase 36 can already take place during a backward movement of the welding wire 13 through targeted heat input via the regulation of the current level in the welding circuit. Thus, even with an existing arc 15, the welding wire 13 can continue to be conveyed away from the workpiece 16 up to a defined time or distance.
• the droplet detachment takes place in such a way that, after reaching the dead center 32, a forward movement of the welding wire 13 takes place until it comes into contact with the workpiece 16. Due to the surface tension of the drop 37 on the welding wire 13 and in the molten bath and other known physical effects acting this is solved by the welding wire 13. By the backward movement of the welding wire 13, the reignition of the arc 13 is favored.
• an increase, in particular a pulse-like increase of the welding current I during the short-circuit phase 39 (not shown) can be carried out.
• the arc phase 36 and the short-circuit phase 39 alternate periodically in the exemplary embodiment shown.
• a movement frequency 40 preferably in the range between 1 Hz and 150 Hz, in particular between 30 Hz and 70 Hz, with which the short-circuit phases 39 and arc phases 36 occur and at least one further welding parameter, such as the material thickness, is set at the welder 1, whereby the number of shorts or short-circuiting phases 39, per second is defined.
• the duration of the periodic arc phases 36 and short-circuit phases 39 can be defined based on the set movement frequency 40. In the following examples, the period corresponding to the movement frequency 40 has been schematically drawn.
• the voltage U or the current I is raised to a first level after the time 35 has been exceeded.
• this level can be set as the working level, which is kept constant during the entire arc phase 36 and the short-circuit phase 39 or runs according to a welding process profile.
• the welding current I has a first component, the working current 41, and at least one further component, the basic current 42, which ensures reliable reignition of the electric arc 15.
• the base current 42 is preferably relatively small compared to the operating current 41, wherein the current strength of the working current 41 may be, for example, 1.5 to 10 times, in particular 4 to 8 times, higher than the current intensity of the base current 42.
• the base current 42 can be, for example, 5 A to 50 A, in particular about 10 to 30 A, while the working current 41 can be, for example, 50 A to 500 A.
• the number of short circuits per second is defined by the set movement frequency 40.
• a period duration 43 can be determined, which is then divided by the control device 4 on the basis of stored values or by a stored calculation module to a time duration 44 for the arc phase 36 and a time duration 45 for the short-circuit phase 39.
• the duration 44 and the duration 45 may be approximately kept constant.
• the time periods 44 and 45 can be readjusted accordingly due to the actual welding process states, so that the corresponding number of short circuits within one second or corresponding to the defined time 38 within the period 43 is always reached a short circuit.
• the user In order to be able to carry out a welding process, the user must set at least one further welding parameter in addition to the movement frequency 40, so that the control device 4 can determine the remaining further required welding parameters, such as the welding current I, the wire feed speed V, etc., based on these at least two parameters and can control or control the welding process in such a way that the short circuits or the short circuit phases 39 are achieved in accordance with the set movement frequency 40.
• the control device 4 can determine the remaining further required welding parameters, such as the welding current I, the wire feed speed V, etc., based on these at least two parameters and can control or control the welding process in such a way that the short circuits or the short circuit phases 39 are achieved in accordance with the set movement frequency 40.
• the control device 4 can determine the remaining further required welding parameters, such as the welding current I, the wire feed speed V, etc., based on these at least two parameters and can control or control the welding process in such a way that the short circuits or the short circuit phases 39 are achieved in accordance with the
• the distance of the welding wire is during the arc phase 36 '33 kept constant to the workpiece 16 and the length of the arc 15 13, so that during the arc phase 36, in particular at least over a large part of the time period 44 for the arc phase 36 the wire feed speed V is adjusted to the melting rate of the welding wire 13 to form the drop.
• a constant wire feed speed V is preferably selected and the welding current I controlled accordingly, so that a constant length of the arc 15 or a constant distance 33 of the welding wire 13 to the workpiece 16 results.
• another parameter, in particular the welding current I used as a constant and the other parameters can be controlled.
• the welding parameters in particular the working current 41 and / or the wire feed speed V, are regulated accordingly by the control device 4.
• the regulation of the working current 41 and the Wire feed speed V is effected by adjusting the working flow 41 to the size of the drop 37 or the amount of additional material to the parameters set in addition to the movement frequency 40, in particular the material thickness, wherein the wire feed speed V during the period 46 to a certain value , which is adapted to the melting rate of the welding wire 13, is kept constant.
• the control is kept simple or the utilization of the control device, in particular the microprocessor load is reduced.
• a constant additional material introduction results, whereby an improved appearance is achieved by the defined appearance of the weld seam.
• the defined initiation of the short circuit within a period of time 47 in the arc phase 36 is preferably carried out by increasing the wire feed speed V, as is shown schematically in the diagram 29. As a result, the distance 33 to the workpiece 16 is correspondingly reduced until a short circuit occurs.
• the welding current I or the operating current 41 is lowered to a low value or reduced to zero in order to hold the drop formed during the period 46 on the welding wire 13 and not to pass it uncontrolled into the molten bath.
• the arc pressure is reduced to a minimum as the distance 33 between electrode or welding wire 13 and workpiece 16 becomes ever smaller. This advantageously has the effect that the contact of the welding wire 13 with the workpiece 16 can not lead to any centrifuging of the droplet 37 or liquefied material, whereby a continuous transition from the arc phase 36 into the short-circuit phase 39 and a strong reduction, up to avoidance, the spatter is achieved.
• the increase of the wire feed speed V and the lowering of the working current 41 causes the short circuit to occur exactly at the time 38, ie at the end of the arc phase 36, which is defined by the set movement frequency 40.
• the Wire feed speed V of the arc phase 36 is maintained within the period 46, and only the welding current I or working current 41 is lowered.
• this requires a longer time 47 to form the short circuit. This procedure is usually only used when a very low movement frequency 40 is set or less material is to be melted off, so that the time duration 46 can be reduced.
• the short circuit at time 35 is opened by a backward movement of the welding wire 13, that is to say the short-circuit phase 39. This completes a period with the period 43.
• a renewed ignition of the arc 15 when lifting the welding wire 13 from the workpiece 16 a new period with the period 43 is initiated.
• FIG. 3 shows a further variant of the method in which the length of the arc 15 is monitored in relation to the distance 33.
• the control device 4 By monitoring the length of the arc 15, for example by evaluating the known welding parameters welding current I and welding voltage U by the control device 4, irregularities on the surface of the workpiece 16 can be detected.
• the welding parameters such as welding current I or wire feed speed V, an undefined short circuit, before or after time 38, can be avoided.
• the wire feed speed V is reduced until the defined length of the arc 15 is reached again (time 51). Subsequently, or at the time 51, the wire feed speed V is raised again to the original, predetermined by the control device 4, constant value.
• the short-circuit phase 39 is initiated at the right time 38 and the defined by the movement frequency 40 period 43 met.
• the arc length correction can also be performed on the welding torch by the welding torch 10 is moved away from the workpiece 16 after detection of a survey 48 on the workpiece 16 and thus in turn the desired length of the arc 15 is produced.
• Such arc length monitoring can also be performed in other embodiments, such as in Fig. 2 or the following figures 4 to 11, in addition.
• FIGS. 4 to 7 show exemplary embodiments of the CMT process with variable welding parameters taking into account the predetermined movement frequency 40.
• the welding parameters during the arc phase 36, to achieve the movement frequency 40 are not kept constant, but for example, a rising or falling course, according to a predetermined profile, may have.
• the length of the arc 15 or the distance 33 from the end of the welding wire 13 to the workpiece 16 can change during the arc phase 36.
• the wire feed speed V is increased by an increasing ramp function or by an increasing profile control until reaching the short circuit at time 38, whereby the end of the welding wire 13 continuously to Workpiece 16 moves.
• the welding current I or operating current 41 drops to a low value or zero in the arc phase 36 after a falling ramp function or by a falling profile control until the short circuit occurs at the time 38.
• the initiation of the short circuit according to the time period 47 already takes place at the beginning of the arc phase 36, since the time duration 46, during which the distance 33 is kept constant, disappears due to the continuous approach of the welding wire 13 to the workpiece 16.
• the duration 44 of the arc phase 36 in the period 43 is identical to the time 47.
• the operating current 41 can run during the arc phase 36 after a rising ramp function or by means of a rising profile regulation during the time period 46 and be lowered to a low value or to zero during initiation of the short circuit during the time period 47.
• the wire feed speed V also after a rising ramp function or based on a rising Profile control increased until reaching the short circuit at time 38.
• the distance 33 is kept approximately constant during the period 46 until the initiation of the short circuit, since the rising wire feed speed V is compensated by the higher melting rate of the welding wire 13 due to the increasing operating current 41.
• the welding current I can be kept constant at the level of the operating current 41 for a certain period of time 56, the wire feed speed V running up to the time 38 of the short circuit after an increasing ramp function or with the aid of a rising profile control.
• an early initiation of the short circuit takes place, in which case, as already known, the working current 41 is lowered during the time period 47.
• the working current 41 is lowered during the time period 47.
• only a low melting rate is caused during the period 47 or the droplets 37 are kept in the liquid state.
• FIG. 7 shows a triangular course of the welding current I or operating current 41 and the wire feed speed V during the arc phase 36, wherein the working current 41 increases or decreases in steps.
• the working current 41 and the wire feed speed V increase during the period 46 and the distance 33 or the length of the arc 15 is kept constant. Subsequently, by the falling wire feed speed V during the period 47, a gradual introduction of the short circuit, which occurs at the defined time 38.
• a particularly advantageous application for the regulation as a function of the arc length lies in the application in the hand Welding, since the dithering movements of the welder are automatically compensated by the control device 4.
• the CMT process can be performed with the set movement frequency 40.
• FIGS. 8 and 9 show time profiles of different process variants for changing the heat input into the workpiece 16.
• the temperature of the molten bath and the amount of filler material is controlled. This is done, for example, by an adjustable heat input at the welding device 1.
• the duration of the arc phase 36 is determined, since here the amount of additive material and the heat input into the workpiece 16 is determined on the basis of the length or time of the upcoming arc 15. For example, as shown in FIG.
• a scale of 1 to 100 may be set for the heat input, with a heat input of 50 means that the duration of the arc phase 36 and the duration of the short-circuit phase 39 are the same. If the value for the heat input is chosen to be greater than 50, the duration of the arc phase 36 increases compared to the duration of the short-circuit phase 39. Conversely, if the value is chosen to be smaller than 50, the duration of the arc phase 36 decreases and the duration of the short-circuit phase increases 39th
• FIG. 8 shows simplified schematic representations of the ratio of arc phase 36 to short-circuit phase 39 in the period 43 in the form of diagrams, different values for heat input into workpiece 16 being selected for the individual diagrams.
• the value 50 is chosen for the heat input
• the value 75 and in the diagram 59 the value 25 is selected, resulting in a corresponding duration for the arc phase 36 and short-circuit phase 39 results.
• a method variant in a simplified schematic representation is shown in which the manually set on the welding device 1 heat input automatically from the Control device 4 is adapted to the material of the workpiece 16.
• the periods 43 and 45 result in different periods 44 and 45 for the arc phase 36 and the short-circuit phase 39, the period durations 43 remaining unchanged.
• the heat input into the workpiece 16 is automatically changed by the variable duration 44 of the arc phase 36. This is done, for example, such that the temperature of the workpiece 16 is monitored, whereby incorrectly set values for the heat input can be compensated.
• the welding process is started with the set value 75 for the heat input and the resulting ratio of arc phase 36 to short-circuit phase 39 after the ignition phase 31 with the period 43.
• the temperature of the workpiece 16 for example by means of temperature sensors or thermal imaging cameras, are detected, whereupon the control device 4 accordingly increases or decreases the value for the heat input or the duration of the arc phase 36 or the time 44 during the welding process.
• a new ratio of arc phase 36 to short-circuit phase 39 is established.
• the heat input into the workpiece 16 may be reduced by a shortened arc phase 36 over one or more period durations 43.
• the value for the heat input is automatically adjusted accordingly by the control device 4. This occurs, for example, in that the value for the heat input manually set on the welding apparatus 1 is set by the control device 4 and thus increased again, as shown at the time 61. Furthermore, the welding device, in particular the welding current I and the wire feed speed V, are adjusted by the control device 4 in accordance with the set ratio of the arc phase 36 to the short-circuit phase 39.
• a certain ratio of the duration of the arc phase 36 to the duration of the short-circuit phase 39 while for example, 2/3 arc phase and 1/3 short-circuit phase, defined by the control device and the position or scale 50 are assigned, wherein when adjusting the value then, for example, a percentage change in the ratio is made.
• a corresponding regulation for adapting the arc phase 36 and the short-circuit phase 39 can additionally take place during special circumstances in the welding process, such as in the unforeseen occurrence of a short circuit to reach the set movement frequency 40 or to return the CMT process to the predefined period lengths 43.
• the heat input into the workpiece 16 can also be controlled via the welding current I or the working current 41. If, for example, more heat input into the workpiece 16 is required, the operating current 41 can be correspondingly increased during the period 46 of the arc phase 36, the time period 44 for the arc phase 36 remaining unchanged. Accordingly, a reduction of the operating current 41 during the period 44 in the arc phase 36 leads to a reduction of the heat input into the workpiece 16.
• FIG. 10 shows an exemplary embodiment in which an undefined short circuit, as caused for example by molten bath movements and / or dithering during manual welding, occurs during the arc phase 36 (time 62).
• an undefined short circuit as caused for example by molten bath movements and / or dithering during manual welding, occurs during the arc phase 36 (time 62).
• the arc phase 36 is interrupted and the time duration 44 is correspondingly shortened, as a result of which the defined short-circuit does not take place at time 38.
• the undefined short circuit at the time 62 is detected by the control device 4, whereby the working current 41 is abruptly lowered to the base current 42 and the wire feed speed V is reversed. or the welding wire 13 is pulled away from the workpiece 16.
• the controller 4 initiates the following short-circuit phase 39 with the predefined time duration 45 and the stored welding parameters, such as the base current 42 and the constant wire feed speed V.
• the defined by the set movement frequency 40 period 43 is exceeded.
• the control device 4 calculates an extended arc phase 36 with the corresponding time duration 44 and adjusts the welding parameters, in particular the welding current I and the wire feed speed V.
• the extended arc phase 36 occurs, which has a longer duration 44.
• the operating current 41 and the wire feed speed are kept constant at a lower value, whereby the same amount of additive material and heat input is achieved, as was the case at the preset and constant arc phase 36 before the undefined short circuit at time 62 by the control device 4.
• the next short circuit is selectively initiated in the following time period 47. This is done, as already known, by lowering the operating current 41 and increasing the wire feed speed so that the next short circuit and the subsequent short circuits again occur at the time points 38 defined at the beginning of the welding process.
• Fig. 11 an embodiment is shown, in which the period 43 and the time period 45 is extended, as may be the case, for example, with dithering during manual welding.
• the droplet detachment in the short-circuit phase 39 following an arc phase 36 may be unintentionally delayed by dithering movements, as shown in the time period 45 beginning at the time 64. This results in a longer period 43.
• the following arc phase 36 and short-circuit phase 39 find with the of the control device 4 instead of predefined time periods 44 and 45, wherein the period 43 is delayed by the extended short-circuit phase 39 in time to the rear.
• the short circuit introduced in the arc phase 36 does not occur at the point in time 38 defined by the movement frequency 40 set at the beginning of the welding process, but at a delayed point in time 65.
• a shortened arc phase 36 or time duration 44 calculated by the control device 4, which starts at the point in time 66 follows.
• the welding parameters in particular the welding current or the working current 41 and the wire feed speed, are increased in the time period 46 such that the amount of additive material and the heat input in the shortened period of time 46 remain unchanged compared to an arc phase 36 with the predefined time periods 44 and 46, respectively.
• Short circuit rasters as described in FIGS. 10 and 11, are solved in such a way that the short-circuit grid and the welding process profile calculated by the control device 4 are restarted, ie a reset takes place. This can be done, for example, after a period 43, ie at the beginning of an arc phase 36, or directly after the occurrence of an undefined short circuit.
• the regulation takes place To maintain the movement frequency 40 preferably in the arc phases 36, since here the heat input or the melt bath temperature and the amount of filler material can be controlled or controlled in an advantageous manner.
• an altered time period 44 or 45 is compensated by the subsequent time period 44 or 45 or process phase, for which purpose a higher processor performance or a higher control engineering effort is required.
• weld spatter By the targeted lowering of the welding current or the working current 41 in the arc phase 36 to initiate the short circuit or the short-circuit phase 39 weld spatter can be avoided.
• An essential advantage of the movement frequency control is that the vibrations of the molten bath can be influenced, in particular the oscillation can be compensated or amplified. For example, at a low frequency of movement 40, the inherent vibration of the molten bath is kept low, resulting in a quiet molten bath with low spatter. Conversely, an increase in the frequency of movement 40 causes the intrinsic vibration of the molten bath to be increased, resulting in better gap bridging.
• a large number of welding parameters are required for a welding process, which are set directly at the welding device 1 or are calculated and controlled indirectly by the control device 4.
• at least two parameters, the movement frequency 40 and at least one further welding parameter, such as, for example, the material are set directly by the operator on the welding device 1. All further welding parameters are detected by the control device 4 and / or calculated and adjusted.
• an input and / or output device 22 is shown in FIG. 12, wherein the set welding parameters are transmitted to the control device 4 of FIG Welding device 1 are forwarded so that from this a corresponding welding process can be controlled or regulated.
• two rotary knobs 68, 69 are arranged in the embodiment shown, with the rotary knob 68, the movement frequency 40 and the rotary knob 69, the material and its thickness can be adjusted.
• the movement frequency 40 of the welding wire 13 is set on a scale of 0 Hz to 150 Hz, wherein the movement frequency 40 defines the number of short circuits per second.
• a display 70 is arranged on the input and / or output device 22, which information about the calculated by the control device 4 welding parameters, such as welding current, wire feed speed, etc., is.
• the buttons 71 which are arranged on the input and / or output device 22, it can be switched over which welding parameter is to be displayed on the display 70.
• light-emitting diodes 72 and abbreviations for the welding parameters, for example A for the welding current are arranged on the input and / or output device 22 below the display 70.
• the light-emitting diodes 72 thus indicate the welding parameter whose value is shown in the display 70.
• the control device 4 may adjust several welding parameters, from which the welding process profile is calculated by the control device 4.
• an additional knob 73 is arranged, via which the heat input into the workpiece 16 on the input and / or output device 22 can be adjusted.
• the rotary knob 73 may, for example, a scale for the value of the heat input of 1 to 100, wherein the value, for example, determines the time duration for the arc phase 36 and ⁇ ch bulkstrom assume.
• the user can specify any number of welding parameters, in particular the welding current I, the welding voltage U, the welding wire diameter, the wire feed speed V, etc., from which the control device 4 calculates the welding process profile.
• These settings can be stored, for example, with one of the buttons 71.
• the user it is also possible for the user to change the values of a welding parameter displayed via the display 70 at any time, whereupon a correction for the further welding parameters is carried out by the control device 4, in order in turn to reach the set movement frequency 40.
• a touch screen or other input and / or output devices 22 known from the prior art to be used instead of the illustrated input and / or output device 22.
• a wide variety of characteristic curves can be stored in a database in the welding machine 1, or the individual values can be calculated by means of corresponding calculation methods.
• the welding parameters in particular the movement frequency 40 and the heat input into the workpiece 16, can also be set or changed via a remote controller integrated in the welding torch 10. This is advantageously used in manual welding processes, since here, in particular during a welding process, the welding parameters can be adapted quickly, unless this is controlled automatically by the control device 4.

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• 2005
  • 2005-05-24 AT AT0088305A patent/AT501995B1/de not_active IP Right Cessation
• 2006
  • 2006-05-18 EP EP06741004.3A patent/EP1901874B1/de active Active
  • 2006-05-18 JP JP2008512644A patent/JP2008542027A/ja active Pending
  • 2006-05-18 WO PCT/AT2006/000205 patent/WO2006125234A1/de not_active Ceased
  • 2006-05-18 US US11/920,516 patent/US9035220B2/en active Active

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