Arc starting method, device, equipment and storage medium for gas metal arc welding

Abstract

This application is applicable to the field of welding technology, and provides a method, device, equipment and storage medium for arc starting in gas metal arc welding. The method includes: after the welding torch is turned on, wire feeding is performed according to the first working mode; when the welding voltage is converted to the short-circuit voltage, a reverse wire drawing control instruction is generated and executed; when the welding voltage is converted to the arcing voltage, wire feeding is performed according to the second working mode; when the welding voltage meets the first preset requirement, a current increasing instruction is generated and executed; after the preset duration of the current increasing instruction runs, the current wire feeding speed and the current welding current are adjusted until the target wire feeding speed and the target welding current during steady-state welding are obtained. This method avoids explosive arc starting by reducing the heat input during the arc starting process (generating a gaseous conductor channel by using an electric field and generating a flashing arc at a small current) and the speed of heat input, and improves the arc starting success rate.

Description

Technical Field

[0001] This application belongs to the field of welding technology, and particularly relates to a method, device, equipment, and storage medium for arc starting in gas metal arc welding. Background Art

[0002] The common arc starting method for gas metal arc welding can be called current-type arc starting. In this arc starting method, when the end of the welding wire makes short-circuit contact with the surface of the workpiece, the welding machine outputs a high-value pulsed current to cause intense melting at the contact between the end of the welding wire and the surface of the workpiece, generating an arc.

[0003] In the above arc starting method, the molten droplet at the end of the welding wire may break away from the welding wire and fly out of the welding area under the action of the gas expansion force formed by the intense ignition of the arc, resulting in metal spatter; or the welding wire may stick due to insufficient heat of the arc current; or the welding wire may burst due to a rapid increase in current; or the arc may repeatedly short-circuit and break due to the mismatch between the welding current and the wire feeding speed; the above possible situations ultimately all manifest as the arc cannot be ignited or cannot be smoothly ignited, resulting in a low arc starting success rate for gas metal arc welding. Summary of the Invention

[0004] In view of this, the embodiments of this application provide a method, device, equipment, and storage medium for arc starting in gas metal arc welding to solve the technical problem of low arc starting success rate in the existing gas metal arc welding technology.

[0005] In a first aspect, the embodiments of this application provide a method for arc starting in gas metal arc welding, the method including:

[0006] After the torch switch is turned on, wire feeding is performed according to a first working mode; the welding current in the first working mode is much smaller than the target welding current during steady-state welding;

[0007] When the welding voltage is converted to the short-circuit voltage, a reverse wire feeding control instruction is generated and executed; wherein, the reverse wire feeding control instruction is used to separate the end of the welding wire from the surface of the workpiece to generate a gaseous conductor channel between the end of the welding wire and the surface of the workpiece under the action of the current welding voltage;

[0008] When the welding voltage is converted to the arc ignition voltage, wire feeding is performed according to a second working mode; wherein, the welding current in the second working mode is greater than the welding current in the first working mode and much smaller than the target welding current;

[0009] When the welding voltage meets the first preset requirement, a current increase instruction is generated and executed;

[0010] After running the current increase instruction for a preset duration, adjust the current wire feeding speed and the current welding current until the target wire feeding speed and the target welding current during steady-state welding are obtained.

[0011] In a feasible implementation manner of the first aspect, when the welding voltage is converted into the short-circuit voltage, generating and executing a reverse wire drawing control instruction includes:

[0012] When the welding voltage is less than a first threshold value, generating a reverse wire drawing control instruction; wherein, the first threshold value is used to represent the welding voltage value at the moment when the end of the welding wire contacts the surface of the workpiece; the reverse wire drawing control instruction includes a wire drawing speed;

[0013] Perform wire drawing according to the wire drawing speed.

[0014] In a feasible implementation manner of the first aspect, when the welding voltage is converted into the arcing voltage, feeding wire according to a second working mode includes:

[0015] When the welding voltage is greater than the first threshold value, feed wire according to a second working mode;

[0016] Wherein, the wire feeding speed in the second working mode is greater than or equal to the wire feeding speed in the first working mode.

[0017] In a feasible implementation manner of the first aspect, when the welding voltage meets a first preset requirement, generating and executing a current increase instruction includes:

[0018] When the welding voltage is re-converted into the short-circuit voltage, generating a current increase instruction;

[0019] According to the current increase instruction, increase the welding current in a preset current adjustment mode.

[0020] In a feasible implementation manner of the first aspect, when the welding voltage meets a first preset requirement, generating and executing a current increase instruction includes:

[0021] When the welding voltage reaches the peak value of the interval, generating a current increase instruction;

[0022] According to the current increase instruction, increase the welding current in a preset current adjustment mode.

[0023] In a feasible implementation manner of the first aspect, the preset current adjustment mode includes:

[0024] Linear adjustment, step adjustment, and curve adjustment.

[0025] In a feasible implementation manner of the first aspect, after running the current increase instruction for a preset duration, the current wire feeding speed and the current welding current are adjusted until the target wire feeding speed and the target welding current during steady-state welding are obtained, including:

[0026] Obtain the current wire feeding speed;

[0027] Determine the number of adjustments and the wire feeding amplitude for each adjustment according to the target wire feeding speed and the current wire feeding speed;

[0028] After running the current increase instruction for a preset duration, starting from the current wire feeding speed, adjust the wire feeding speed according to the number of adjustments and the wire feeding amplitude for each adjustment until the target wire feeding speed is reached;

[0029] And obtain the current welding current;

[0030] Determine the current amplitude for each adjustment according to the target welding current, the current welding current, and the current wire feeding speed;

[0031] After running the current increase instruction for a preset duration, starting from the current welding current, adjust the welding current according to the number of adjustments and the current amplitude for each adjustment until the target welding current is reached.

[0032] In a second aspect, an arc starting device for gas metal arc welding provided by an embodiment of the present application includes:

[0033] A first wire feeding module, configured to feed wire according to a first working mode after the torch switch is turned on; the welding current in the first working mode is much smaller than the target welding current during steady-state welding;

[0034] A reverse wire feeding module, configured to generate and execute a reverse wire feeding control instruction when the welding voltage is converted to a short-circuit voltage; wherein, the reverse wire feeding control instruction is used to separate the end of the welding wire from the surface of the workpiece, so as to generate a gaseous conductor channel between the end of the welding wire and the surface of the workpiece under the action of the current welding voltage;

[0035] A second wire feeding module, configured to feed wire according to a second working mode when the welding voltage is converted to an arcing voltage; wherein, the welding current in the second working mode is greater than the welding current in the first working mode and much smaller than the target welding current;

[0036] A current increase module, configured to generate and execute a current increase instruction when the welding voltage meets a first preset requirement;

[0037] A steady-state welding module, configured to adjust the current wire feeding speed and the current welding current after running for a preset duration of the current increase instruction until the target wire feeding speed and the target welding current during steady-state welding are obtained.

[0038] In a third aspect, an arc starting device for gas metal arc welding according to an embodiment of the present application includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of any method in the first aspect are implemented.

[0039] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the steps of any method in the first aspect are implemented.

[0040] In a fifth aspect, an embodiment of the present application provides a computer program product, which, when running on a terminal device, causes the terminal device to execute the method of any one of the first aspects.

[0041] In the arc starting method for gas metal arc welding provided by the embodiment of the present application, after the torch switch is turned on, wire feeding is performed according to the first working mode. When the welding voltage is converted to the short-circuit voltage (i.e., when the end of the welding wire contacts the surface of the workpiece), a reverse wire drawing instruction is generated and executed, so that a small gap is generated between the end of the welding wire and the surface of the workpiece. An extremely high electric field strength is generated between the small gaps of the current welding voltage, and the shielding gas will be ionized under the extremely high electric field strength, thereby establishing a gaseous conductor channel (i.e., generating a flash arc) between the small gaps, creating favorable conditions for arc starting (an initial arc can be generated under the action of lower heat); since the end of the welding wire is separated from the surface of the workpiece, the welding voltage will rise. When the welding voltage is converted to the arcing voltage, wire feeding is performed according to the second working mode, and an initial arc is generated under the action of the current welding current (initial arc generation stage).

[0042] Since the welding current in the first working mode and in the short - circuit state is much smaller than the target welding current during steady - state welding, it will not cause thermal melting of the welding wire and generates extremely little heat. Therefore, the wire feeding speed does not need to be coordinated with the welding current. During wire feeding according to the second working mode, due to the mechanical inertia of the wire feeder during reverse wire drawing operation, the speed of the end of the welding wire is relatively small. Therefore, not much heat needs to be added to melt a large amount of the welding wire. Thus, the welding current in the second working mode can also be much smaller than the target welding current during steady - state welding, and the coordination between the wire feeding speed and the welding current does not need to be particularly precise, as long as it can generate an initial arc under low - heat action. The initial arc is ignited by the welding current (small current) in the second working mode. On the one hand, it avoids the violent and explosive arc ignition caused by large current in the prior art. On the other hand, it effectively avoids the repeated short - circuit and open - circuit of the arc caused by the mismatch between the heat input of the welding wire (determined by the welding current) and the wire feeding speed.

[0043] Immediately afterwards, when the welding voltage meets the first preset requirement (indicating that the initial arc has been generated), a current - increasing instruction is generated and executed, so that the welding current matches the wire feeding speed to complete a smooth arc - ignition connection (stable stage of the initial arc), stabilize the initial arc, and at the same time reduce the size and quantity of metal spatter particles.

[0044] Then, according to the target wire feeding speed and target welding current during steady - state welding, the current wire feeding speed and current welding current are adjusted (stable - arc transition stage) until entering the main welding stage of steady - state arcing, successfully achieving smooth arc ignition.

[0045] In summary, the above - mentioned method avoids the violent and explosive arc ignition of the wire - bursting type by reducing the heat input during the arc - ignition process (creating convenient conditions for arc ignition through an extremely strong electric field, so that an initial arc can be generated under low - heat action); at the same time, by dividing the arc - ignition process into multiple stages (initial - arc generation stage, initial - arc stable stage, and transition stage to the steady - state arc), the sequential increase of the welding current and wire feeding speed is realized, reducing the speed and mode of heat input, enabling the heat input and melting amount of the welding wire (reflected by the welding current) to adaptively match the wire feeding speed, ensuring the smooth transition of the initial arc to the steady - state arc, greatly improving the arc - ignition success rate, and ensuring the stability of arc ignition without generating huge metal spatter.

[0046] It can be understood that the beneficial effects of the above - mentioned second to fifth aspects can refer to the relevant descriptions in the first aspect above, and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0048] Figure 1 It is a schematic flowchart of the arc starting method for gas metal arc welding provided by an embodiment of the present application;

[0049] Figure 2 It is a timing diagram of the arc starting process for gas metal arc welding provided by an embodiment of the present application;

[0050] Figure 3 It is a schematic flowchart of the arc starting method for gas metal arc welding provided by another embodiment of the present application;

[0051] Figure 4 It is a schematic structural diagram of the arc starting device for gas metal arc welding provided by an embodiment of the present application;

[0052] Figure 5 It is a schematic diagram of the hardware composition of the arc starting equipment for gas metal arc welding provided by an embodiment of the present application. Detailed implementation manners

[0053] In the following description, for the purpose of illustration rather than limitation, specific details such as specific system structures and technologies are proposed to thoroughly understand the embodiments of the present application. However, those skilled in the art should clearly understand that the present application can also be implemented in other embodiments without these specific details. In other cases, the detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present application.

[0054] The reference to "an embodiment" or "some embodiments" etc. described in the specification of the present application means that specific features, structures, or characteristics described in connection with the embodiment are included in one or more embodiments of the present application. Thus, the statements "in an embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "include", "comprise", "have" and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0055] The common arc-starting method for gas metal arc welding mainly relies on the extremely high heat generated by an instantaneous high-pulse current and the extremely large arc constriction force to start the arc. Since the current is very large during arc starting, the contact area between the end of the welding wire and the workpiece surface is violently melted. On the one hand, it is easy to have a mismatch between the thermal melting amount and the wire feeding speed, resulting in repeated short circuits and open circuits of the arc. On the other hand, the molten droplets at the end of the welding wire may break away from the welding wire and fly out of the welding area under the action of the gas expansion force formed by the violent ignition of the arc, resulting in metal spatter. Or the wire may stick due to insufficient heat from the arc current, or the wire may break explosively due to a rapid increase in current. Or the end of the conducting nozzle may be melted due to excessive heat generation from the arc and excessive back burning of the wire. Or the arc may repeatedly short circuit and open circuit due to a mismatch between the welding current and the wire feeding speed. All the above possible situations ultimately result in the arc not being able to be ignited or not being able to be stably ignited, leading to a low arc-starting success rate for gas metal arc welding.

[0056] The following uses specific embodiments to exemplarily illustrate the technical solution of this application and how the technical solution of this application solves the above technical problems. It should be noted that the specific embodiments listed below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0057] Figure 1 is a schematic flow chart of an arc-starting method for gas metal arc welding provided in an embodiment of this application. As Figure 1 shown, this arc-starting method for gas metal arc welding is used to obtain the welding voltage during the arc-starting process in real time and adjust the wire feeding speed and welding current according to the welding voltage. This method includes:

[0058] S10. After the torch switch is turned on, wire feeding is performed according to the first working mode.

[0059] In this embodiment, the wire feeding speed in the first working mode is a preset value.

[0060] Exemplarily, after the welding machine detects that the torch switch is pressed, it sends a forward wire feeding instruction to the wire feeder and indicates a preset wire feeding speed, and the wire feeder feeds wire according to this preset wire feeding speed.

[0061] In this embodiment, the welding current in the first working mode is much smaller than the target welding current during steady-state welding. Since the welding current in the first working mode is much smaller than the target welding current during steady-state welding, it will not cause thermal melting of the wire, and the heat generated is extremely small and can be approximately ignored. Therefore, the current wire feeding speed does not need to be coordinated with the welding current, and wire feeding can be performed according to the preset wire feeding speed, and there will be no short circuits and open circuits of the arc caused by a mismatch between the wire heating amount (determined by the welding current) and the wire feeding speed.

[0062] S20. When the welding voltage is converted to the short - circuit voltage, generate and execute a reverse wire - feeding control instruction.

[0063] The purpose of this step is to generate a gaseous conductor channel between the end of the welding wire and the surface of the workpiece, thus creating favorable conditions for generating the initial - state arc. Specifically, it can be achieved by reverse wire - feeding of the welding wire.

[0064] Before the end of the welding wire contacts the surface of the workpiece, the welding voltage is characterized as the no - load voltage. As the welding wire is fed, the end of the welding wire makes a short - circuit contact with the surface of the workpiece at a certain moment. Since the current starts to flow, the welding voltage drops from the no - load voltage to a low - value voltage, and this low - value voltage is the short - circuit voltage. Therefore, when the welding voltage is converted to the short - circuit voltage, it indicates that the end of the welding wire contacts the surface of the workpiece.

[0065] In this embodiment, when the welding voltage is converted to the short - circuit voltage, it may refer to the welding voltage dropping below a first threshold value. Here, the first threshold value is a preset value, which is used to characterize the welding voltage value at the moment when the end of the welding wire contacts the surface of the workpiece.

[0066] In this embodiment, the welding machine generates and executes a reverse wire - feeding control instruction, which may include the welding machine generating a reverse wire - feeding control instruction and sending this reverse wire - feeding control instruction to the wire - feeding machine, so that the wire - feeding machine performs a wire - feeding operation according to this reverse wire - feeding control instruction. Among them, the reverse wire - feeding control instruction is used to separate the end of the welding wire from the surface of the workpiece to generate a gaseous conductor channel between the end of the welding wire and the surface of the workpiece under the action of the current welding voltage.

[0067] Optionally, after the end of the welding wire contacts the surface of the workpiece, when the welding machine detects that the welding voltage drops below the first threshold value, it generates a reverse wire - feeding control instruction and sends this reverse wire - feeding control instruction to the wire - feeding machine. This reverse wire - feeding control instruction includes the wire - feeding speed, and the wire - feeding machine performs wire - feeding according to this wire - feeding speed, so as to form a tiny gap between the end of the welding wire and the surface of the workpiece.

[0068] The current welding voltage can generate an extremely high electric - field strength in this tiny gap, and the shielding gas is ionized under this extremely high electric - field strength, so as to establish a gaseous conductor channel (i.e., generate a flash arc) between the tiny gaps, creating favorable gas - conduction conditions for arc ignition.

[0069] In practical applications, due to mechanical inertia and the commutation time of the motor, after the wire - feeding machine executes the reverse wire - feeding control instruction, the end of the welding wire will still move closer to the surface of the workpiece for wire - feeding and will not immediately reverse and retract, resulting in the short - circuit state lasting for a period of time (during this process, the welding voltage is less than the first threshold value). When the speed of the end of the welding wire drops to zero, the wire - feeding action stops, and the end of the welding wire starts to retract at the set wire - feeding speed.

[0070] Optionally, during the process of retracting the welding wire end at a set wire drawing speed, in order to increase the resistance heat on the wire extension length, the welding machine can increase the welding current.

[0071] S30. When the welding voltage is converted to the arcing voltage, wire feeding is performed according to the second working mode; wherein, the welding current in the second working mode is greater than the welding current in the first working mode and much smaller than the target welding current.

[0072] The purpose of this step is to generate the initial arc and at the same time preheat the welding wire resistively and arcingly.

[0073] With the execution of the reverse wire drawing control instruction, the welding wire end leaves the working surface again. At this time, the welding voltage is converted from the short - circuit voltage to the arcing voltage, specifically manifested as the welding voltage being greater than the first threshold in step 20 again.

[0074] Exemplarily, when the welding machine detects that the welding voltage is converted to the arcing voltage and performs wire feeding according to the second working mode, it may mean that after the welding machine detects that the welding voltage is greater than the first threshold, it sends a forward wire feeding command to the wire feeder and provides a preset wire feeding speed.

[0075] Among them, the wire feeding speed in the second working mode is greater than or equal to the wire feeding speed in the first working mode.

[0076] Since a gaseous conductor channel has been generated between the welding wire end and the workpiece surface, an initial arc can be generated under the action of lower heat. Therefore, the initial arc can be gently established under the action of the welding current in the second working mode.

[0077] During the wire feeding according to the second working mode (initial arc generation stage), due to mechanical inertia, the wire feeding speed at the beginning of the welding wire end is small. Therefore, not much heat is required to melt a large amount of the welding wire. Thus, the welding current in the second working mode can also be much smaller than the target welding current during steady - state welding, and the coordination between the wire feeding speed and the welding current does not need to be particularly precise, as long as it can meet the requirement of generating an initial arc under low heat.

[0078] Optionally, in order to preheat the welding wire, the welding current in the second working mode is greater than the welding current in the first working mode.

[0079] S40. When the welding voltage meets the first preset requirement, generate and execute a current increase instruction.

[0080] The purpose of this step is to maintain the stability of the initial arc welding process. During this process, the welding current needs to be well coordinated with the wire feeding speed, so as to control the arc force and the pinching force for the disconnection of the short - circuit necking to reduce the size and quantity of metal splash particles.

[0081] In this embodiment, the first preset requirement may include that the welding voltage is re-converted to the short-circuit voltage and the welding voltage reaches the peak value within the range.

[0082] After wire feeding is performed according to the second working mode, due to mechanical inertia and the commutation time of the motor, the end of the welding wire will continue to draw back in the reverse direction until the speed of the end of the welding wire is reduced to zero. During this process, the welding voltage will continue to increase and reach the peak value within the range when the speed of the end of the welding wire is reduced to zero; then the end of the welding wire will approach the surface of the workpiece, and the speed of the end of the welding wire will gradually increase. At this time, since the distance between the end of the welding wire and the surface of the workpiece decreases, the welding voltage will gradually decrease, and when the end of the welding wire comes into contact with the surface of the workpiece again, it will be re-converted to the short-circuit voltage.

[0083] In a feasible implementation manner, when the welding voltage of the welding machine meets the first preset requirement, generating and executing the current increase instruction may include: when the welding voltage is re-converted to the short-circuit voltage, generating the current increase instruction, and according to the current increase instruction, increasing the welding current in a preset current adjustment mode.

[0084] Wherein, the preset current adjustment mode may include: linear adjustment, step adjustment, and curve adjustment.

[0085] Exemplarily, when the welding voltage is re-converted to the short-circuit voltage, it indicates that the end of the welding wire is in contact with the surface of the workpiece, that is, a short circuit occurs again. At this time, the welding machine generates a current increase instruction, which can be specifically manifested as increasing the current in a preset current mode to force the short-circuit necking and the separation of the molten droplet from the molten pool, and returning the welding process to the arcing state; then as the wire feeder continues to feed wire, the welding voltage is re-converted to the short-circuit voltage again, and the current welding current forces the short-circuit necking and the separation of the molten droplet from the molten pool again, so that the welding process returns to the arcing state again, thereby realizing the alternating cycle switching of short circuit - arcing in the welding process, that is, realizing the stability of the initial arc establishment in the short-circuit metal transfer welding process.

[0086] Furthermore, in the above process, the welding current and the wire feeding speed should be adaptively coordinated to control the arc force and the breaking force of the short-circuit necking disconnection, so as to reduce the size and quantity of metal splash particles.

[0087] In another feasible implementation manner, when the welding voltage of the welding machine meets the first preset requirement, generating and executing the current increase instruction may include: when the welding voltage reaches the peak value within the range, generating the current increase instruction, and according to the current increase instruction, increasing the welding current in a preset current adjustment mode.

[0088] S50. After running for the preset duration of the current increase instruction, adjust the current wire feeding speed and the current welding current until the target wire feeding speed and the target welding current during steady-state welding are obtained.

[0089] The purpose of this step is to enable the initial arc to successfully develop into a steady-state arc in the main welding process according to the set adjustment method.

[0090] In this embodiment, the running current increase instruction is preset for a period of time, indicating that the welding state alternates between short circuit and arcing and lasts for the preset time; at this time, the initial arc burns stably, so the initial arc can be developed into a steady-state arc in the main welding process, thus successfully achieving arc ignition.

[0091] In this embodiment, adjusting the current wire feeding speed and the current welding current may refer to sequentially adjusting the current wire feeding speed multiple times according to the different target wire feeding speeds during steady-state welding, such as step or linear adjustment.

[0092] In this stage, the welding current should match the wire feeding speed.

[0093] In this embodiment, after obtaining the target wire feeding speed and the target welding current during steady-state welding, the main welding process starts. Thereafter, the welding machine controls the current and voltage of the main welding process in a set mode under the condition of a constant wire feeding speed to complete the planned welding process.

[0094] For a clearer illustration of this embodiment, please refer to Figure 2 . Figure 2 It is the timing diagram of the arc ignition process for gas metal arc welding provided by the embodiment of the present application.

[0095] As Figure 2 shown, line 1 is the speed of the wire end, line 2 is the welding voltage, line 3 is the welding current, and line 4 is the set wire feeding speed instruction.

[0096] At time T1, the welding torch switch is turned on and the shielding gas starts to be delivered. At this time, the welding voltage shows the no-load voltage.

[0097] At time T2, the welding machine generates a first forward wire feeding instruction, sends this first forward wire feeding instruction to the wire feeder, and indicates a preset wire feeding speed. The wire feeder feeds wire according to this preset wire feeding speed. For example, this preset wire feeding speed can be 6.0 mpm. In this state, the welding voltage still shows the no-load voltage, and the welding current is a value much smaller than the target welding current. For example, the welding current in the current state is not greater than 5 A.

[0098] At time T3, the welding voltage converts to the short-circuit voltage, specifically manifested as the welding voltage being less than the first threshold, where the first threshold is a preset value. For example, the first threshold can be 13 V. At this time, the welding machine generates a reverse wire drawing control instruction. Specifically, it can be referred to that the wire feeding speed in line 4 is set to a negative value.

[0099] The welding machine sends the reverse wire drawing control instruction to the wire feeder. The reverse wire drawing control instruction includes the wire drawing speed, and the wire feeder draws the wire according to this wire drawing speed. Due to mechanical inertia and the commutation time of the motor, the welding wire will still be fed forward, but the speed of the end of the welding wire will decrease. After the speed of the end of the welding wire decreases to zero, the end of the welding wire starts to draw back reversely until the end of the welding wire separates from the workpiece surface at time T4, indicating the end of the short-circuit state between the end of the welding wire and the workpiece surface. At this time, a tiny gap is generated between the end of the welding wire and the workpiece surface. Under the action of the arcing threshold voltage, an extremely high electric field intensity can be generated between this tiny gap, and the gas is ionized under this extremely high electric field intensity, thereby establishing a gaseous conductor channel (i.e., generating a flashing arc) between the end of the welding wire and the workpiece surface, creating favorable gas ionization conditions for arc ignition.

[0100] At time T4, a gaseous conductor channel has been established between the end of the welding wire and the workpiece surface, and the welding voltage is converted into the arcing voltage, specifically manifested as the welding voltage being greater than the first threshold. At this time, a relatively small current can be used to gently ignite the initial arc.

[0101] At time T4, when the welding voltage is converted into the arcing voltage, wire feeding is performed according to the second working mode. Specifically, it can mean that the welding machine generates a second forward wire feeding instruction and sends this second forward wire feeding instruction to the wire feeder. The second forward wire feeding instruction contains the set wire feeding speed, and the wire feeder feeds the wire according to this set wire feeding speed. Due to mechanical inertia and the commutation time of the motor, after the welding machine sends the second forward wire feeding instruction to the wire feeder, the speed of the end of the welding wire still shows a negative wire drawing speed until the speed of the end of the welding wire becomes zero at time T5; during this process, as the distance between the end of the welding wire and the workpiece surface increases, the welding voltage also gradually increases and reaches the peak value of the interval at time T5; immediately afterwards, the speed of the end of the welding wire becomes positive, and at this time the end of the welding wire moves closer to the workpiece surface again, and at time T6, the end of the welding wire contacts the workpiece surface again, and at this time the welding voltage is converted back into the short-circuit voltage.

[0102] In order to stably generate the initial arc, before time T4, the welding machine can output a relatively small welding current (the welding current in the second working mode), which is greater than the welding current at time T2 (the welding current in the first working mode), so as to perform resistive preheating on the welding wire.

[0103] Since the speed of the wire end is always small during the time between T4 and T6, it is not necessary to increase a large amount of heat to melt the wire significantly. Therefore, the welding current in the second working mode can also be much smaller than the target welding current during steady-state welding, and the coordination between the wire feeding speed and the welding current does not need to be particularly precise, as long as it can generate an initial arc under low heat. On the premise that a gaseous conductor channel is established between the wire end and the workpiece surface, the initial arc is gently ignited at a small current (the welding current in the second working mode). On the one hand, it avoids the violent and rough arc ignition caused by a large current in the prior art, and on the other hand, it effectively avoids the repeated short circuit and open circuit of the arc caused by the mismatch between the wire heating amount (welding current) and the wire feeding speed.

[0104] At time T6, after the welding voltage is re-converted to the short-circuit voltage, the welding machine generates a current increase command at this time, and according to the current increase command, the welding current is increased in a preset current adjustment mode. As Figure 2 shown, the preset current adjustment mode is linear adjustment.

[0105] The purpose of this process is to maintain the stability of the welding process in the initial arc state. During this process, the welding current needs to be well coordinated with the wire feeding speed. During this process, the speed of the wire end continues to increase until it reaches the set value of the wire feeding speed in the second working mode at time T7.

[0106] The welding state cycles between short circuit and arcing and lasts for a period of time, maintaining the stability of the initial arc welding process and also ensuring the stability of the molten pool, and then the transition to the main welding process can begin. Specifically, at time T7, the current wire feeding speed and the current welding current are adjusted until the target wire feeding speed and the target welding current during steady-state welding are obtained. For example, at time T9, the target wire feeding speed and the target welding current during steady-state welding are reached, and the arc ignition is successfully achieved.

[0107] During the above process, the welding current should be matched with the wire feeding speed, and the welding voltage alternates between the arcing voltage and the short-circuit voltage.

[0108] The arc starting method for gas metal arc welding provided by the embodiment of the present application reduces the heat input during the arc starting process (by creating favorable conditions for arc starting through a very strong electric field intensity, so that an initial arc can be generated under the action of lower heat), avoiding the violent and explosive arc starting of the wire explosion type; at the same time, by dividing the arc starting process into multiple stages (initial arc generation stage, initial arc stabilization stage, and transition stage to the steady-state arc), the welding current and wire feeding speed are adaptively increased sequentially, reducing the speed and mode of heat input, so that the heating amount and melting amount of the welding wire (reflected by the welding current) can be adaptively matched with the wire feeding speed, ensuring the smooth transition of the initial arc to the steady-state arc burning, greatly improving the arc starting success rate, and ensuring the stability of arc starting without generating huge metal spatter.

[0109] Figure 3 is a schematic flow chart of the arc starting method for gas metal arc welding provided by another embodiment of the present application, which describes Figure 1 a possible implementation manner of step 50 in the embodiment. The purpose of this embodiment is to enable the initial arc to successfully develop into the steady-state arc of the main welding process according to the set adjustment method, which can be specifically realized by adaptively adjusting the wire feeding speed and welding current sequentially multiple times. During this process, the welding current should be matched with the wire feeding speed.

[0110] As Figure 3 shown, after running the preset duration of the current increase instruction, the current wire feeding speed and the current welding current are adjusted until the target wire feeding speed and the target welding current during steady-state welding are obtained, including:

[0111] S501. Obtain the current wire feeding speed.

[0112] S502. Determine the number of adjustments and the wire feeding amplitude for each adjustment according to the target wire feeding speed and the current wire feeding speed.

[0113] Among them, the target wire feeding speed is the wire feeding speed required for the main welding process, that is, the wire feeding speed corresponding to the steady-state combustion of the arc, which is a preset value.

[0114] Optionally, the target wire feeding speed may be greater than, equal to, or less than the current wire feeding speed. Therefore, the wire feeding amplitude for each adjustment is used to describe the change increment of the wire feeding speed (this increment is a vector).

[0115] Optionally, determining the number of adjustments and the wire feeding amplitude for each adjustment according to the target wire feeding speed and the current wire feeding speed may include determining the number of adjustments according to the difference between the target wire feeding speed and the current wire feeding speed. And since the welding current is matched with the wire feeding speed, the number of adjustments of the welding current is the same as the number of adjustments of the wire feeding speed.

[0116] Optionally, after determining the number of adjustments, the wire speed change rate for each adjustment and the duration of each adjustment can be determined, and then the wire feeding amplitude for each adjustment can be determined based on the wire speed change rate and the duration of each adjustment. Among them, the wire speed change rate in different adjustment stages can be different, and the duration of different adjustment stages can also be different.

[0117] For example, if the number of adjustments is 2, the adjustment stage is divided into two segments. To make the initial arc transition smoothly, the wire speed change rate in the first adjustment stage is less than that in the second stage, and the duration of the first adjustment stage is greater than that of the second adjustment stage.

[0118] S503. After the preset duration of the operating current increase instruction, starting from the current wire feeding speed, adjust the wire feeding speed according to the number of adjustments and the wire feeding amplitude for each adjustment until the target wire feeding speed is reached.

[0119] Among them, the adjustment method can be segmented linear adjustment.

[0120] In this embodiment, during the transition from the initial arc to the steady-state arc, the steady-state arc welding current needs to match the wire feeding speed. Therefore, the method of this embodiment further includes the following steps:

[0121] Step 1: Obtain the current welding current.

[0122] Step 2: Determine the current amplitude for each adjustment according to the target welding current, the current welding current, and the current wire feeding speed.

[0123] Step 3: After the preset duration of the current increase instruction, starting from the current welding current, adjust the welding current according to the number of adjustments and the current amplitude for each adjustment until the target welding current is reached.

[0124] To illustrate this embodiment more clearly, please refer to Figure 2 . Figure 2 This is the timing diagram of the arc starting process of the gas metal arc welding provided by the embodiment of the present application.

[0125] As Figure 2 shown, after T7 (i.e., after the preset duration of the operating current increase instruction), the current wire feeding speed is adjusted in a segmented linear manner until the target wire feeding speed is reached at T9. As shown by line 4, the adjustment of the wire feeding speed is a two-stage adjustment. T7 to T8 is the first adjustment stage, and T8 to T9 is the second adjustment stage. Among them, the wire speed change rate in the first adjustment stage is less than that in the second stage, and the duration of the first adjustment stage is greater than that of the second adjustment stage.

[0126] Accordingly, since the welding current needs to match the wire feeding speed, the welding current is also adjusted in two levels. The first adjustment stage is from T7 to T8, and the second adjustment stage is from T8 to T9.

[0127] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The order of execution of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0128] Based on the arc starting method for gas metal arc welding provided by the above embodiments, the embodiments of the present invention further provide a device embodiment for implementing the above method embodiments.

[0129] Figure 4 The following is a schematic structural diagram of an arc starting device for gas metal arc welding provided by an embodiment of the present application. As Figure 4 shown, the arc starting device 40 for gas metal arc welding includes:

[0130] A first wire feeding module 401, configured to feed wire according to a first working mode after the torch switch is turned on; the welding current in the first working mode is much smaller than the target welding current during steady-state welding;

[0131] A reverse wire drawing module 402, configured to generate and execute a reverse wire drawing control instruction when the welding voltage is converted to a short-circuit voltage; wherein, the reverse wire drawing control instruction is used to separate the end of the welding wire from the surface of the workpiece, so as to generate a gaseous conductor channel between the end of the welding wire and the surface of the workpiece under the action of the current welding voltage;

[0132] A second wire feeding module 403, configured to feed wire according to a second working mode when the welding voltage is converted to an arcing voltage; wherein, the welding current in the second working mode is greater than the welding current in the first working mode and much smaller than the target welding current;

[0133] A current increasing module 404, configured to generate and execute a current increasing instruction when the welding voltage meets a first preset requirement;

[0134] A steady-state welding module 405, configured to adjust the current wire feeding speed and the current welding current after running the current increasing instruction for a preset duration until the target wire feeding speed and the target welding current during steady-state welding are obtained.

[0135] Optionally, the reverse wire drawing module 402, configured to generate and execute a reverse wire drawing control instruction when the welding voltage is converted to a short-circuit voltage, includes:

[0136] When the welding voltage is less than the first threshold, a reverse wire feeding control instruction is generated; wherein, the first threshold is used to represent the welding voltage value at the moment when the end of the welding wire contacts the surface of the workpiece; the reverse wire feeding control instruction includes the wire feeding speed;

[0137] Wire feeding is performed according to the wire feeding speed.

[0138] Optionally, the second wire feeding module 403 is configured to perform wire feeding according to the second working mode when the welding voltage is converted into the arcing voltage, including:

[0139] When the welding voltage is greater than the first threshold, wire feeding is performed according to the second working mode;

[0140] Wherein, the wire feeding speed in the second working mode is greater than or equal to the wire feeding speed in the first working mode.

[0141] Optionally, the current increasing module 404 is configured to generate and execute a current increasing instruction when the welding voltage meets the first preset requirement, including:

[0142] When the welding voltage is reconverted into the short - circuit voltage, a current increasing instruction is generated;

[0143] According to the current increasing instruction, the welding current is increased in a preset current adjustment mode.

[0144] Optionally, the current increasing module 404 is configured to generate and execute a current increasing instruction when the welding voltage meets the first preset requirement, including:

[0145] When the welding voltage reaches the peak value of the interval, a current increasing instruction is generated;

[0146] According to the current increasing instruction, the welding current is increased in a preset current adjustment mode.

[0147] Optionally, the preset current adjustment mode includes: linear adjustment, step adjustment and curve adjustment.

[0148] Optionally, the steady - state welding module 405 is configured to adjust the current wire feeding speed and the current welding current after running the current increasing instruction for a preset duration until the target wire feeding speed and the target welding current during steady - state welding are obtained, including:

[0149] Obtain the current wire feeding speed;

[0150] Determine the number of adjustments and the wire feeding amplitude for each adjustment according to the target wire feeding speed and the current wire feeding speed;

[0151] After running the current increasing instruction for a preset duration, starting from the current wire feeding speed, adjust the wire feeding speed according to the number of adjustments and the wire feeding amplitude for each adjustment until the target wire feeding speed is reached;

[0152] and obtain the current welding current;

[0153] Determine the current amplitude for each adjustment according to the target welding current, the current welding current, and the current wire feeding speed;

[0154] After running the current increasing instruction for a preset duration, starting from the current welding current, adjust the welding current according to the number of adjustments and the current amplitude for each adjustment until the target welding current is reached.

[0155] Figure 4 The arc starting device for MIG welding provided by the illustrated embodiment can be used to execute the technical solutions in the above method embodiments, and its implementation principle and technical effects are similar, which will not be elaborated here in this embodiment.

[0156] Figure 5 is a schematic diagram of an arc starting device for MIG welding provided by an embodiment of the present application. As Figure 5 shown, the arc starting device 50 for MIG welding includes: at least one processor 501, a memory 502, and a computer program stored in the memory 502 and executable on the processor 501. The arc starting device for MIG welding further includes a communication component 503, wherein the processor 501, the memory 502, and the communication component 503 are connected through a bus 504.

[0157] When the processor 501 executes the computer program, it implements the steps in the above-mentioned method embodiments of various arc starting methods for MIG welding, such as Figure 1 the steps S10 to S50 in the illustrated embodiment. Alternatively, when the processor 501 executes the computer program, it implements the functions of each module / unit in the above-mentioned device embodiments, such as Figure 4 the functions of the illustrated modules 401 to 405.

[0158] Exemplarily, the computer program can be divided into one or more modules / units, and the one or more modules / units are stored in the memory 502 and executed by the processor 501 to complete the present application. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, and these instruction segments are used to describe the execution process of the computer program in the arc starting device 50 for MIG welding.

[0159] Those skilled in the art can understand, Figure 5It is merely an example of the arc starting device for gas metal arc welding and does not constitute a limitation on the arc starting device for gas metal arc welding. For example, the arc starting device for gas metal arc welding can be a welding machine control system equipped with a wire feeder.

[0160] An embodiment of the present application also provides a computer-readable storage medium storing a computer program, which when executed by a processor can implement the steps in the above-mentioned method embodiments.

[0161] An embodiment of the present application provides a computer program product, which when running on the arc starting device for gas metal arc welding enables the arc starting device for gas metal arc welding to implement the steps in the above-mentioned method embodiments when executed.

[0162] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, to implement all or part of the processes in the above-mentioned method embodiments of the present application, a computer program can be used to instruct the relevant hardware to complete. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file or some intermediate form, etc. The computer-readable medium can at least include: any entity or device capable of carrying the computer program code to the photographing device / terminal device, recording medium, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal, and software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disc, etc. In some jurisdictions, according to legislation and patent practice, the computer-readable medium cannot be an electrical carrier signal and a telecommunication signal.

[0163] In the above embodiments, the descriptions of the various embodiments have their own emphases. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0164] Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0165] In the embodiments provided in the present application, it should be understood that the disclosed device / network device and method can be implemented in other ways. For example, the device / network device embodiments described above are only illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in electrical, mechanical or other forms.

[0166] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0167] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for arc starting in gas metal arc welding, characterized in that the method Including: After the torch switch is turned on, wire feeding is performed according to the first working mode; The welding current in the first working mode is much smaller than the target welding current during steady-state welding; When the welding voltage is converted to the short-circuit voltage, a reverse wire-drawing control instruction is generated and executed; wherein, the reverse wire-drawing control instruction is used to separate the end of the welding wire from the surface of the workpiece, so as to generate a gaseous conductor channel between the end of the welding wire and the surface of the workpiece under the action of the current welding voltage; When the welding voltage is converted to the arcing voltage, wire feeding is performed according to the second working mode; wherein, the welding current in the second working mode is greater than the welding current in the first working mode and much smaller than the target welding current; When the welding voltage meets the first preset requirement, a current increase instruction is generated and executed, including: generating a current increase instruction when the welding voltage is re-converted to the short-circuit voltage or the welding voltage reaches the peak value of the interval; After running the current increase instruction for a preset duration, the current wire-feeding speed and the current welding current are adjusted until the target wire-feeding speed and the target welding current during steady-state welding are obtained.

2. The arc starting method for gas metal arc welding according to claim 1, characterized in that, The generating and executing the reverse wire-drawing control instruction when the welding voltage is converted to the short-circuit voltage includes: When the welding voltage is less than the first threshold value, a reverse wire-drawing control instruction is generated; wherein, the first threshold value is used to represent the welding voltage value at the moment when the end of the welding wire contacts the surface of the workpiece; the reverse wire-drawing control instruction includes the wire-drawing speed; Wire drawing is performed according to the wire-drawing speed.

3. The arc starting method for the gas metal arc welding according to claim 2, characterized in that The wire feeding is performed according to the second working mode when the welding voltage is converted to the arcing voltage, including: When the welding voltage is greater than the first threshold value, wire feeding is performed according to the second working mode; Wherein, the wire-feeding speed in the second working mode is greater than or equal to the wire-feeding speed in the first working mode.

4. The arc starting method for gas metal arc welding according to claim 1, characterized in that, The generating and executing the current increase instruction when the welding voltage meets the first preset requirement includes: According to the current increase instruction, the welding current is increased in a preset current adjustment mode.

5. The arc starting method for gas metal arc welding according to claim 4, characterized in that, The preset current adjustment mode includes: Linear adjustment, step adjustment, and curve adjustment.

6. The arc starting method for gas metal arc welding according to any one of claims 1-5, characterized in that, After running the current increase instruction for a preset duration, adjusting the current wire-feeding speed and the current welding current until the target wire-feeding speed and the target welding current during steady-state welding are obtained, including: Obtaining the current wire-feeding speed; Determining the number of adjustments and the wire-feeding amplitude for each adjustment according to the target wire-feeding speed and the current wire-feeding speed; After running the current increase instruction for a preset duration, starting from the current wire-feeding speed, adjusting the wire-feeding speed according to the number of adjustments and the wire-feeding amplitude for each adjustment until the target wire-feeding speed is reached; And obtaining the current welding current; Determining the current amplitude for each adjustment according to the target welding current, the current welding current, and the current wire-feeding speed; After running the current increase instruction for a preset duration, starting from the current welding current, adjusting the welding current according to the number of adjustments and the current amplitude for each adjustment until the target welding current is reached.

7. An arc starting device for gas metal arc welding, which is used to implement the method described in any one of claims 1-6, characterized in that, The device includes: The first wire feeding module is used to feed wire according to the first working mode after the welding torch switch is turned on; the welding current in the first working mode is much smaller than the target welding current during steady-state welding. The reverse wire drawing module is used to generate and execute a reverse wire drawing control instruction when the welding voltage is converted to the short-circuit voltage; wherein, the reverse wire drawing control instruction is used to separate the end of the welding wire from the surface of the workpiece, so as to generate a gaseous conductor channel between the end of the welding wire and the surface of the workpiece under the action of the current welding voltage. The second wire feeding module is used to feed wire according to the second working mode when the welding voltage is converted to the arcing voltage; wherein, the welding current in the second working mode is greater than the welding current in the first working mode and much smaller than the target welding current. The current increasing module is used to generate and execute a current increasing instruction when the welding voltage meets the first preset requirement. The steady-state welding module is used to adjust the current wire feeding speed and the current welding current after running the current increasing instruction for a preset duration until the target wire feeding speed and the target welding current during steady-state welding are obtained.

8. An arc starting device for gas metal arc welding, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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