A welding control method and welding machine

Abstract

The application discloses a welding control method and a welding machine, and relates to the technical field of welding. The welding control method comprises a plurality of molten drop transition periods, each molten drop transition period comprises a short circuit stage and an arc burning stage, and the control method comprises the following steps: adding an arc breaking stage in each molten drop transition period, so that each molten drop transition period comprises the short circuit stage, the arc burning stage and the arc breaking stage; wherein adding the arc breaking stage in each molten drop transition period comprises the following steps: outputting a base value current after the arc burning current output of the arc burning stage is ended; adjusting a current instruction to make the arc extinguish when the current instruction reaches the base value current, so as to enter the arc breaking stage; in the arc breaking stage, the welding wire is in a forward wire feeding state, and detection of the short circuit stage is carried out. The application effectively avoids the occurrence of phenomena such as molten drop repulsion transition and molten drop falling difficulty by adding the arc breaking stage, so that welding spatter is reduced, arc stability is improved, and welding quality is improved.

Description

A welding control method and welding machine Technical Field

[0001] This invention relates to the field of welding technology, and more specifically to a welding control method and a welding machine. Background Technology

[0002] Magnesium alloys are among the lightest engineering structural materials, possessing advantages such as abundant reserves, high specific strength, good electromagnetic shielding, high recyclability, good thermal conductivity, and high magnetic permeability. They have broad application prospects in aerospace, automotive, and electronics industries. The extensive industrial application of magnesium alloys requires reliable joining technologies, as many components need to be joined to similar or dissimilar materials to achieve more complex geometries. To achieve this, welding technology has received particular attention, and its development is a key factor in expanding the application of magnesium alloys in structural component manufacturing.

[0003] With the continuous improvement of welding and servo motor technologies, digital welding machines are increasingly being accepted and used by more and more customers due to their superior welding performance. High-frequency variable-speed wire feeding has also become possible, with cold metal transfer welding technology being a typical example. This process can reduce welding spatter and heat input to some extent when welding magnesium alloys. However, due to the low density of magnesium alloys and the repulsive effect of arc spot pressure, difficulties in droplet repulsion and droplet detachment still exist during the welding process, leading to welding spatter and arc instability. Summary of the Invention

[0004] The purpose of this invention is to provide a welding control method and welding machine to solve the problems of large welding spatter and poor arc stability in the welding process in the prior art.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0006] In a first aspect, this application discloses a welding control method, including multiple droplet transfer cycles, each droplet transfer cycle including a short-circuit stage and an arc-ignition stage. The control method includes: adding an arc-breaking stage within each droplet transfer cycle, so that each droplet transfer cycle includes a short-circuit stage, an arc-ignition stage, and an arc-breaking stage; wherein, adding the arc-breaking stage within each droplet transfer cycle includes:

[0007] The base current is output in response to the end of the arc current output during the arcing phase;

[0008] When the current command reaches the base current, the current command is adjusted to extinguish the arc and enter the arc-breaking stage.

[0009] During the arc interruption phase, the welding wire is fed in the forward direction, and a short-circuit detection is performed.

[0010] Furthermore, the step of adjusting the current command to extinguish the arc in response to the current command reaching the base current includes:

[0011] After the current command reaches the base current value within 0 to 10 ms, the current command is adjusted so that the actual output current value is the first preset current value and the output voltage value is higher than the first preset voltage value, so as to extinguish the arc.

[0012] Furthermore, during the arc-breaking phase, placing the welding wire in a forward-feeding state includes:

[0013] If the welding wire is stopped during the arc-ignition stage, then during the arc-extinguishing stage, the welding wire is adjusted to the forward feeding state, wherein the wire feeding speed is 15m / min~60m / min;

[0014] If the welding wire is fed in the forward direction during the arc-ignition phase, it should remain fed in the forward direction during the arc-extinguishing phase, with a wire feeding speed of 15m / min to 60m / min.

[0015] Furthermore, the period between the end of the arc current output and the start of the base current output also includes:

[0016] Depending on the welding material, welding gas, or welding wire diameter, the output base current is adjusted, and when the current command reaches the base current, the droplet size is 1.2 to 1.5 times the welding wire diameter.

[0017] Furthermore, the detection and control of the arcing stage includes:

[0018] Collect the output voltage value of the welding machine;

[0019] If the output voltage value is higher than the second voltage preset value and the duration is greater than 100us, it is judged to be in an arcing state.

[0020] After 0-1ms of detecting the arc state, the welding wire is adjusted from the negative retraction state to the stop wire feeding state or from the negative retraction state to the positive wire feeding state, while the arc current is continuously output for 1.0-6.0ms; wherein the arc current value is 100A-500A.

[0021] Furthermore, the detection and control of the short-circuit phase includes:

[0022] Collect the output voltage value of the welding machine;

[0023] If the output voltage value is less than the third preset voltage value and the duration is greater than 100us, it is judged to be a short circuit state.

[0024] When a short circuit is detected, the current control waveform under the short circuit condition is output, and after 0~1ms, the welding wire is retracted in the negative direction at a speed of 15m / min~60m / min, and the arcing stage is detected.

[0025] Furthermore, the current control waveform under the output short-circuit state includes:

[0026] Different current control waveforms are output depending on the welding material, welding gas, or welding wire diameter.

[0027] Furthermore, the duration of each droplet transition cycle is 6~20ms.

[0028] Secondly, this application discloses a welding machine, comprising:

[0029] Memory, used to store instructions;

[0030] A processor for executing the instructions to cause the welding machine to perform operations implementing the welding control method as described in any of the first aspects.

[0031] Thirdly, this application discloses a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the welding control method as described in any of the first aspects.

[0032] According to the above technical solution, the beneficial effects of the present invention are as follows:

[0033] This invention adds an arc-breaking stage to the short-circuit stage and the arc-ignition stage. That is, each droplet transition cycle includes three processes: the arc-ignition stage, the arc-breaking stage, and the short-circuit stage. During the arc-breaking stage, the arc is extinguished. The existence of the arc-breaking stage can reduce the welding heat input and effectively avoid phenomena such as droplet repulsion during transition and difficulty in droplet detachment, thereby reducing welding spatter, improving arc stability, and improving welding quality. Attached Figure Description

[0034] Figure 1 is a flowchart of the control method of the present invention;

[0035] Figure 2 is an overall schematic diagram of the control method according to Embodiment 1 of the present invention;

[0036] Figure 3 is an overall flowchart of the control method according to Embodiment 1 of the present invention;

[0037] Figure 4 is a schematic diagram of the overall control method of Embodiment 2 of the present invention;

[0038] Figure 5 is an overall flowchart of the control method of Embodiment 2 of the present invention. Detailed Implementation Methods

[0039] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0040] This application provides a MIG welding control method that adds an arc-breaking stage, so that each droplet transition cycle includes three processes: an arc-ignition stage, an arc-breaking stage, and a short-circuit stage. The transition cycle of each droplet is 6~20ms. The presence of the arc-breaking stage can reduce welding heat input and effectively avoid droplet repulsion and droplet detachment, thereby reducing welding spatter, improving arc stability, and improving welding quality.

[0041] The welding control method described in this application is mainly used to address the problems of large welding spatter and poor arc stability during MIG welding of magnesium alloys and other lightweight materials. The other lightweight materials mentioned can be lightweight alloys or carbon fiber composites. Besides the magnesium alloys mentioned in the background art, lightweight alloys can also be titanium alloys, aluminum alloys, and other lightweight alloys.

[0042] The welding control method of this application can be used not only for lightweight materials, but also for welding metals such as zinc, iron, steel, and copper and their alloys.

[0043] As shown in Figure 1, the welding control method of this application includes multiple droplet transfer cycles, each droplet transfer cycle including a short-circuit stage and an arc-ignition stage. The control method includes: adding an arc-breaking stage within each droplet transfer cycle, so that each droplet transfer cycle includes a short-circuit stage, an arc-ignition stage, and an arc-breaking stage; wherein, adding an arc-breaking stage within each droplet transfer cycle includes: outputting a base value current in response to the end of the arc-ignition stage; adjusting the current command to extinguish the arc in response to the current command reaching the base value current, so as to enter the arc-breaking stage; in the arc-breaking stage, the welding wire is in a forward wire feeding state, and the short-circuit stage is detected.

[0044] This application effectively avoids phenomena such as droplet repulsion and difficulty in droplet detachment by adding an arc interruption stage, thereby reducing welding spatter, improving arc stability, and enhancing welding quality.

[0045] In a further embodiment, as shown in FIG2, each droplet transition cycle includes a short-circuit stage, an arc-ignition stage, and an arc-breaking stage arranged sequentially. That is, the short-circuit stage, the arc-ignition stage, and the arc-breaking stage have a sequential order within the droplet transition cycle. First comes the short-circuit stage, then the arc-ignition stage, and finally the arc-breaking stage. After the arc-breaking stage ends, the short-circuit stage of the next droplet transition cycle begins.

[0046] In some embodiments, as shown in FIG3, for the convenience of describing the arc-breaking stage, which is a key part of this application, the description begins with the arc-ignition stage, proceeds through the arc-breaking stage, and finally enters the short-circuit stage. In this application, the short-circuit stage, arc-ignition stage, and arc-breaking stage of each droplet transition cycle are performed sequentially, as shown in FIG2. It cannot be the order of short-circuit stage first, then arc-breaking stage, and finally arc-ignition stage; nor can it be the order of arc-ignition stage first, then short-circuit stage, and finally arc-breaking stage; nor can it be the order of arc-breaking stage first, then arc-ignition stage, and finally short-circuit stage.

[0047] As shown in Figures 2 and 3, the steps of the present invention can be further defined as follows: After detecting the arc-burning stage, the welding wire is adjusted from a negative wire-drawing state to a stopped wire-feeding state or to a positive wire-feeding state, while simultaneously outputting an arc-burning current to cause the molten droplet to grow. After the arc-burning current output ends, a base current is output. When the current command reaches the base current, arc-breaking detection begins, and the arc is extinguished by adjusting the current command, entering the arc-breaking stage. After entering the arc-breaking stage, the welding wire is placed in a positive wire-feeding state, and short-circuit detection is performed. When a short-circuit stage is detected, the welding wire is adjusted from a positive wire-feeding state to a negative high-speed wire-drawing state, and arc-burning detection is performed.

[0048] When an arc is detected, repeat the above steps.

[0049] In the arc-breaking stage, this application can promote the occurrence of short circuits and increase the droplet transfer frequency by using a forward high-speed wire feeding method, thereby improving weld formation. Moreover, the existence of the arc-breaking stage can reduce welding heat input and reduce the occurrence of phenomena that hinder droplet transfer caused by the presence of electric arc, thereby reducing welding spatter.

[0050] In the short-circuit phase, this application uses a higher wire retraction speed to reduce welding spatter and promote arc generation.

[0051] The present application will be further described below through specific embodiments. Embodiment 1

[0052] As shown in Figure 2-3, in a specific embodiment, the welding control method includes the following control steps:

[0053] Step 1: Collect the output current and output voltage values ​​of the welding machine, and determine the short circuit, arcing and arc breaking states. The output current value is the actual output current value of the welding machine during the welding process, and the output voltage value is the actual output voltage value of the welding machine during the welding process.

[0054] In this step, the output current and output voltage values ​​can be acquired through the acquisition module in the welding machine, or through the voltage acquisition circuit and the current acquisition circuit.

[0055] Step 2: When performing arc detection, if the output voltage value is higher than the second preset voltage value and the duration is greater than 100us, it is judged to be in an arc state. When the arc state is detected, after a delay of 0~1ms, the welding wire is adjusted from the negative retraction state to the stop wire feeding state, and the arc current is output at the same time. The magnitude of the arc current is 100A~500A and the duration is 1.0~6.0ms.

[0056] In this step, the preset value of the second voltage can be 9-11V, or more specifically, the preset value of the second voltage is 10V.

[0057] Step 3: After the arc current output ends, start outputting the base current. The base current value should be less than 72-88A, and further, the base current should be less than 80A.

[0058] Step 4: When the current command reaches the base current, arc interruption detection begins.

[0059] Step 5: When the current command reaches the base current, after a delay of 0~10ms, adjust the current command so that the actual output current value is the first preset current value and the output voltage value is higher than the first preset voltage value. At this time, the arc is extinguished and the arc breaking stage begins.

[0060] In this step, the first preset current value is 0A.

[0061] In this step, the first preset voltage value is 54-66V, and in a further embodiment, the first preset voltage value is 60V.

[0062] Step 6: After entering the arc breaking stage, immediately feed the wire at a forward wire feeding speed of 15m / min to 60m / min, and after a delay of T5 (200 to 500us), start the short circuit detection.

[0063] Step 7: When performing short circuit detection, if the output voltage value is lower than the third preset voltage value and the duration is greater than 100us, it is judged as a short circuit state. When a short circuit state is detected, the current control waveform under the short circuit state is immediately output, and after a delay of 0~1ms, the welding wire is retracted in the negative direction at a speed of 15m / min~60m / min. At the same time, the arc detection is started.

[0064] In this step, the preset value of the third voltage is 7.2-8.8V, and further, the preset value of the third voltage is selected as 8V.

[0065] Once an arc is detected, repeat steps 2 through 7 above, cycling through the process until welding is complete.

[0066] The MIG welding control method of this application involves three processes for each droplet transfer: the arc-ignition stage, the arc-breaking stage, and the short-circuit stage, with each droplet transfer cycle lasting 6 to 20 ms.

[0067] In summary, this application adds an arc-breaking stage to the droplet transfer process in MIG welding. That is, each droplet transfer cycle includes three processes: the arc-ignition stage, the arc-breaking stage, and the short-circuit stage, and the cycle of each droplet transfer is 6~20ms. The presence of the arc-breaking stage can reduce welding heat input and spatter, and improve arc stability.

[0068] This invention enables arc-interrupted welding by effectively controlling the current output and wire feed output during the arc-burning stage, thereby reducing welding heat input and avoiding the repulsive droplet transfer phenomenon caused by the presence of the arc. This further reduces welding spatter and improves arc stability. This technology can further reduce welding heat input and spatter on the basis of cold metal transfer technology, and is very suitable for welding lightweight materials such as magnesium alloys and other materials that are sensitive to heat input.

[0069] In a further embodiment, after the arc current output ends and before the base current is output, a second base current can be output first, depending on the welding material, welding gas or welding wire diameter, and then the base current is output. When the current command reaches the base current, the droplet size is 1.2 to 1.5 times the welding wire diameter.

[0070] In this embodiment, the second base current may or may not be output, and the second base current is usually larger than the first base current.

[0071] In a further embodiment, in step 7, after entering a short-circuit state, different shapes of current control waveforms can be output depending on the welding material, welding gas, or welding wire diameter. Example 2

[0072] As shown in Figures 4-5, this embodiment mainly describes the differences from Embodiment 1, namely the wire feeding situation during the arc-burning stage and the arc-breaking stage. The rest is the same as Embodiment 1, and will not be described in this embodiment.

[0073] In this embodiment, the difference from Embodiment 1 lies in step 2. Specifically, step 2 in this embodiment involves: during arc detection, if the output voltage value is higher than the second preset voltage value and the duration is greater than 100µs, an arc state is determined. When an arc state is detected, after a delay of 0-1ms, the welding wire is adjusted from a negative retraction state to a positive wire feeding state, and an arc current is output simultaneously. The magnitude of the arc current is 100A-500A, and the duration is 1.0-6.0ms. In this step, the positive wire feeding speed is 15m / min-60m / min.

[0074] Therefore, in this embodiment, step 6 is as follows: after entering the arc breaking stage, continue to feed the wire at a forward wire feeding speed of 15m / min to 60m / min, delay for T5 (200 to 500us), and then start short circuit detection.

[0075] Compared to Example 1, this example is more suitable for welding metals such as zinc, iron, steel, and copper, and their alloys. Example 3

[0076] In one embodiment of this application, a welding machine is also disclosed, comprising: a memory for storing instructions; and a processor for executing the instructions, causing the welding machine to perform the operation of the welding control method of any of the above embodiments.

[0077] The components of the welding machine may include, but are not limited to: at least one processor, at least one memory, and a bus connecting different system components (including the memory and the processor). The processor may be connected to the welding unit of the welding machine, which generates heat in response to the welding current output by the processor to achieve welding of the workpiece.

[0078] The memory stores program code that can be executed by a processor, causing the processor to perform the steps described in the "Exemplary Methods" section above, according to various exemplary embodiments of the present invention. For example, the processor can perform the steps shown in FIG2 or FIG3.

[0079] The memory may include readable media in the form of volatile memory, such as random access memory (RAM) and / or cache memory, and may further include read-only memory (ROM).

[0080] The memory may also include programs / utilities having a set (at least one) of program modules, including but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0081] A bus can represent one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus that uses any of the various bus structures.

[0082] The welding machine can also communicate with one or more external devices (such as keyboards, pointing devices, Bluetooth devices, etc.), one or more devices that enable user interaction with the welding machine, and / or any device that enables the welding machine to communicate with one or more other computing devices (such as routers, modems, etc.). This communication can be achieved through input / output (I / O) interfaces. Furthermore, the welding machine can communicate with one or more networks (such as local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via a network adapter. The network adapter communicates with other modules of the welding machine via a bus.

[0083] It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in conjunction with the welding machine, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0084] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, terminal device, or network device, etc.) to execute the methods according to the embodiments of this disclosure.

[0085] In exemplary embodiments of this disclosure, a computer-readable storage medium is also provided, on which a program product capable of implementing the methods described above is stored. In some possible embodiments, various aspects of the invention may also be implemented as a program product comprising program code that, when the program product is run on a terminal device, causes the terminal device to perform the steps of the various exemplary embodiments of the invention described in the "Exemplary Methods" section of this specification.

[0086] The program product for implementing the above-described method according to embodiments of the present invention may employ a portable compact disc read-only memory (CD-ROM) and include program code, and may run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited thereto. In this document, the readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0087] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0088] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of outputting, propagating, or transmitting programs for use by or in conjunction with an instruction execution system, apparatus, or device.

[0089] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0090] Program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0091] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or its equivalents are included in this invention.

Claims

1. A welding control method, comprising multiple droplet transfer cycles, each droplet transfer cycle including a short-circuit stage and an arc-ignition stage, characterized in that, The control method includes: adding an arc-extinguishing stage within each droplet transition cycle, so that each droplet transition cycle includes a short-circuit stage, an arc-ignition stage, and an arc-extinguishing stage; wherein, adding an arc-extinguishing stage within each droplet transition cycle includes: outputting a base value current in response to the end of the arc-ignition current output during the arc-ignition stage; adjusting the current command to extinguish the arc in response to the current command reaching the base value current, so as to enter the arc-extinguishing stage; during the arc-extinguishing stage, the welding wire is in a forward wire feeding state, and short-circuit stage detection is performed; wherein, adjusting the current command to extinguish the arc in response to the current command reaching the base value current includes: after the current command reaches the base value current for 0~10ms, adjusting the current command so that the actual output current value is a first preset current value, and the output voltage value is higher than the first preset voltage value, so as to extinguish the arc.

2. The welding control method according to claim 1, characterized in that, During the arc-breaking phase, keeping the welding wire in a forward-feeding state includes: if the welding wire was in a stopped-feeding state during the arc-burning phase, then during the arc-breaking phase, adjusting the welding wire to a forward-feeding state, wherein the wire feeding speed is 15m / min to 60m / min; if the welding wire was in a forward-feeding state during the arc-burning phase, then maintaining the forward-feeding state of the welding wire during the arc-breaking phase, wherein the wire feeding speed is 15m / min to 60m / min.

3. The welding control method according to claim 1, characterized in that, Between the end of the arc current output and the start of the base current output, the base current is output according to different welding materials, welding gases or welding wire diameters, and when the current command reaches the base current, the droplet size is 1.2 to 1.5 times the welding wire diameter.

4. The welding control method according to claim 1, characterized in that, The detection and control of the arc-ignition stage includes: acquiring the output voltage value of the welding machine; in response to the output voltage value being higher than the second preset voltage value and the duration being greater than 100us, it is determined to be in an arc-ignition state; 0~1ms after detecting the arc-ignition state, the welding wire is adjusted from the negative retraction state to the wire feeding stop state or the welding wire is adjusted from the negative retraction state to the wire feeding positive state, while continuously outputting the arc-ignition current for 1.0~6.0ms; wherein, the magnitude of the arc-ignition current is 100A~500A.

5. The welding control method according to claim 1, characterized in that, The detection and control of the short circuit stage includes: acquiring the output voltage value of the welding machine; in response to the output voltage value being less than the third preset voltage value and the duration being greater than 100us, it is judged to be a short circuit state; when a short circuit state is detected, the current control waveform under the short circuit state is output, and after 0~1ms, the welding wire is negatively retracted at a speed of 15m / min~60m / min, and the arc stage is detected.

6. The welding control method according to claim 5, characterized in that, The current control waveform under the output short-circuit state includes: outputting current control waveforms of different shapes according to different welding materials, welding gases or welding wire diameters.

7. The welding control method according to any one of claims 1-6, characterized in that, The duration of each droplet transition cycle is 6~20ms.

8. A welding machine, characterized in that, include: Memory, used to store instructions; A processor for executing the instructions, causing the welding machine to perform operations that implement the welding control method as described in any one of claims 1-7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the welding control method as described in any one of claims 1-7.

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