Arc striking method applied to gas metal arc welding and welding equipment

Abstract

The invention provides an arc striking method applied to gas metal arc welding and welding equipment. The arc striking method comprises the following steps: providing arc striking current, and establishing an arc; the voltage between the welding gun and the workpiece is detected, and when the detected voltage is smaller than or equal to a preset voltage threshold value, it is judged that arc striking succeeds; and / or the current output to the workpiece by the welding gun is detected, and when the detected current is larger than or equal to a preset current threshold value, it is judged that arc striking succeeds; and after determining that arc striking succeeds, cutting off the arc striking current. According to the arc striking method, splashing caused by welding wire explosion or jackscrew at the arc striking moment can be avoided, the safety and stability of the arc striking process are improved, and meanwhile automatic control over the arc striking process is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of electric welding machines, and in particular to an arc starting method and welding equipment used in metal electrode gas shielded welding. Background Art

[0002] Gas shielded welding is an arc welding technology widely used in industrial production. At the beginning of welding, it is necessary to establish an arc between the workpiece and the welding wire to melt the workpiece and the welding wire and form a weld, which is called "arc striking".

[0003] At present, when the gas shielded welding arc is struck, the welding wire needs to be in direct contact with the workpiece to form a current loop. At the moment the two come into contact, heat is generated due to the contact impedance, the welding wire melts and forms a gap, thus igniting the arc.

[0004] However, it is difficult for users to determine the state of the welding wire before striking the arc, such as whether there are residual molten droplets and the size of the molten droplets. If the residual molten droplets are too large, the high current during arc striking may cause the molten droplets to explode, produce spatter, or even break the welding wire, requiring re-strike.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0006] Based on this, the embodiments of the present application provide an arc striking method and welding equipment for metal electrode gas shielded welding, which can avoid spattering caused by wire breakage or wire top at the moment of arc striking, improve the safety and stability of the arc striking process, and realize automatic control of the arc striking process.

[0007] According to some embodiments, the present application provides, on one hand, an arc starting method for metal-electrode gas shielded welding, comprising:

[0008] Provide arc starting current to establish arc;

[0009] Detecting the voltage between the welding gun and the workpiece, and determining that the arc is successfully struck when the detected voltage is less than or equal to a preset voltage threshold; and / or detecting the current output from the welding gun to the workpiece, and determining that the arc is successfully struck when the detected current is greater than or equal to a preset current threshold;

[0010] After determining that the arc striking is successful, the arc striking current is cut off.

[0011] In some embodiments, providing the arc striking current comprises:

[0012] Obtain welding wire specifications and / or welding gas;

[0013] The current value of the arc striking current is determined according to the welding wire specification.

[0014] In some embodiments, the welding wire specifications include welding wire diameter and / or welding wire material.

[0015] In some embodiments, the arc striking current has a current value ranging from 30A to 200A.

[0016] In some embodiments, when detecting the current output from the welding gun to the workpiece, the preset current threshold is configured to be greater than 0A.

[0017] In some embodiments, after determining that arc striking is successful, the arc striking current is continuously provided until a preset time is reached, and then the arc striking current is cut off.

[0018] In some embodiments, the preset time is greater than or equal to 100 μs.

[0019] In some embodiments, providing the arc striking current comprises:

[0020] An arc-starting pulse is output to start an arc, and an oscillation frequency range of the arc-starting pulse includes 10kHz to 100MHz.

[0021] In some embodiments, providing the arc striking current comprises:

[0022] An arc striking pulse is output to start an arc, and a voltage range of the arc striking pulse includes 1 kV to 1000 kV.

[0023] According to some embodiments, the present application further provides a welding device for gas metal arc welding, wherein the welding device uses the arc striking method provided in the aforementioned embodiments to strike an arc.

[0024] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application.

[0025] The embodiments of the present application may or at least have the following advantages:

[0026] In metal-metal gas shielded welding, the arc striking method provided in the embodiment of the present application is adopted, and an electric field is formed between the welding gun and the workpiece through the arc striking current, so that the air is ionized to produce an ionization channel and a relatively stable arc is generated, thereby avoiding spattering caused by wire breakage or wire top at the moment of arc striking, thereby improving the safety and stability of the arc striking process.

[0027] In addition, the embodiment of the present application also monitors the arc striking state and determines whether the arc striking is successful by real-time detection of the voltage between the welding gun and the workpiece and / or the current output by the welding gun to the workpiece. After determining that the arc striking is successful, the embodiment of the present application can cut off the arc striking current to avoid damage to the workpiece caused by over-melting of the welding wire and reduce unnecessary energy consumption. In this way, the automatic control of the arc striking process is achieved without manual intervention, which is also conducive to improving work efficiency.

[0028] In addition, the embodiments of the present application do not need to rely on the root state of the welding wire, and can achieve smooth arc initiation regardless of whether there are residual molten droplets or poor contact in the welding wire. Therefore, it also solves the technical problem of failure of traditional metal-metal gas welding due to unclear welding wire state before arc initiation, and achieves effective improvement of traditional metal-metal gas welding technology.

[0029] Other advantages, objectives and features of the present application will be described in the following description to some extent, and will be apparent to those skilled in the art based on the following examination and study, or can be taught from the practice of the present application to some extent. The objectives and other advantages of the present application can be achieved and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings.

[0031] Figure 1 A schematic flow chart of an arc striking method provided in some embodiments of the present application;

[0032] Figure 2 A schematic diagram of a flow chart for providing arc striking current in an arc striking method provided in some embodiments of the present application. DETAILED DESCRIPTION

[0033] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0034] In addition, the accompanying drawings are only schematic illustrations of the present application and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or implemented in one or more hardware modules or integrated circuits, or implemented in different networks and / or processor devices and / or microcontroller devices.

[0035] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0036] Metal Ingot (MIG) welding is a gas shielded welding technology widely used in industrial production. At present, when MIG arc is started, the welding wire needs to be in direct contact with the workpiece to form a current loop. At the moment the two come into contact, heat is generated due to the contact impedance, the welding wire melts and forms a gap, thus igniting the arc.

[0037] However, it is difficult for users to determine the state of the welding wire before striking the arc, such as whether there are residual molten droplets and the size of the molten droplets. If the residual molten droplets are too large, the high current during arc striking may cause the molten droplets to explode, produce spatter, or even break the welding wire. Multiple arc striking is required to enter a stable welding state, which increases welding time and equipment wear.

[0038] Based on the above considerations, the present application provides an arc striking method and welding equipment for metal arc gas shielded welding, which can avoid spattering caused by wire breakage or wire top at the moment of arc striking, improve the safety and stability of the arc striking process, and realize automatic control of the arc striking process. The details will be described in the subsequent embodiments.

[0039] In one aspect, the present application provides an arc starting method for MIG welding. Figure 1 The arc striking method may specifically include the following steps S100 to S300:

[0040] S100: Provide arc striking current to establish an arc.

[0041] S200: Detecting the voltage between the welding gun and the workpiece, and determining that arc striking is successful when the detected voltage is less than or equal to a preset voltage threshold; and / or detecting the current output from the welding gun to the workpiece, and determining that arc striking is successful when the detected current is greater than or equal to a preset current threshold.

[0042] S300: After determining that arc striking is successful, the arc striking current is cut off.

[0043] In MIG, the arc striking method provided by the above arc striking method is adopted, and an electric field is formed between the welding gun and the workpiece through the arc striking current, so that the air is ionized to produce an ionization channel and a relatively stable arc is generated, thereby avoiding spattering caused by wire breakage or wire top at the moment of arc striking, thereby improving the safety and stability of the arc striking process.

[0044] In addition, the arc striking method can monitor the arc striking state and judge whether the arc striking is successful by real-time detection of the voltage between the welding gun and the workpiece and / or the current output from the welding gun to the workpiece. After determining that the arc striking is successful, the arc striking method can cut off the arc striking current to avoid damage to the workpiece caused by over-melting of the welding wire and reduce unnecessary energy consumption. In this way, the automatic control of the arc striking process is realized without manual intervention, which is also conducive to improving work efficiency.

[0045] In addition, the above-mentioned arc striking method does not need to rely on the state of the root of the welding wire. Regardless of whether there are residual molten droplets or poor contact in the welding wire, smooth arc striking can be achieved. Therefore, it also solves the technical problem of failure of traditional MIG due to unclear state of the welding wire before arc striking, and realizes effective improvement of traditional MIG technology.

[0046] The details of each step in the above arc striking method are further described below.

[0047] For step S100, specifically, an arc striking pulse can be outputted by a high-frequency oscillation circuit to generate an arc striking current, which generates an electromagnetic field at the tip of the welding wire, thereby forming a high-voltage electric field between the tip of the welding wire and the workpiece, ionizing the air, and generating an arc.

[0048] See also Figure 2 In some embodiments, the process of providing the arc striking current may specifically include the following steps S110 to S120:

[0049] S110: Obtain welding wire specifications and / or welding gas.

[0050] S120: Determine the current value of the arc striking current according to the welding wire specification.

[0051] In step S100, welding gas refers to a gas used to protect the weld area and improve welding quality during welding. The welding wire specification may include welding wire diameter and / or welding wire material, but is not limited thereto. For example, the welding wire specification may also include welding wire type, welding wire length, welding wire electrical conductivity and thermal conductivity, etc.

[0052] In the above embodiment, the current value of the arc starting current is determined by the welding wire specifications (such as welding wire diameter, welding wire material, etc.), which can accurately match the physical properties and melting requirements of welding wires of different specifications to ensure arc starting efficiency and stability. Accurately matched arc starting current can effectively reduce spatter caused by overmelting of welding wire or excessive droplet, improve the quality of welding joints, and is particularly suitable for high-precision welding scenarios or welding of special materials. In addition, when the welding wire specifications are small, accurately matching the current value of the arc starting current by the welding wire specifications is also conducive to avoiding unnecessary current waste.

[0053] In other embodiments, a general current may be preset as the arc striking current. For example, a general current with a current value of 30A to 200A may be preset as the arc striking current; that is, the current value range of the arc striking current may specifically include 30A to 200A. As an example, the current value range of the arc striking current may specifically be 30A, 50A, 100A, 150A or 200A, etc.

[0054] The setting of universal current does not require analyzing the specifications of welding wires one by one, which reduces the complexity of operation and is particularly suitable for scenarios where welding wires of multiple specifications are mixed or welding tasks are frequently switched. The above embodiment designs the current value range of the arc striking current to be 30A to 200A, which can adapt to most welding tasks, meet general welding needs under non-extreme conditions, and improve the flexibility of welding. With the above embodiment, users can quickly start welding without complex adjustments, which is conducive to improving production rhythm.

[0055] The embodiment of the present application does not specifically limit the oscillation frequency of the arc-starting pulse used to start the arc. In some embodiments, the arc-starting pulse can be a high-frequency high-voltage pulse with a frequency range of 10kHz to 100MHz. For example, the oscillation frequency of the arc-starting pulse can be 10kHz, 200kHz, 500kHz, 1MHz or 100MHz, etc.

[0056] The embodiment of the present application does not specifically limit the voltage of the arc-starting pulse used to start the arc. In some embodiments, the arc-starting pulse can be a high-frequency high-voltage pulse with a voltage range of 1 kV to 1000 kV. For example, the voltage of the arc-starting pulse can be 1 kV, 50 kV, 100 kV, 500 kV or 1000 kV, etc.

[0057] For step S200, the voltage between the welding gun and the workpiece can be detected, and when the detected voltage is less than or equal to the preset voltage threshold, it is determined that the arc is successfully struck, or the current output from the welding gun to the workpiece is detected, and when the detected current is greater than or equal to the preset current threshold, it is determined that the arc is successfully struck, or when the detected voltage is less than or equal to the preset voltage threshold and the detected current is greater than or equal to the preset current threshold, both are satisfied, the arc is successfully struck. All the above three judgment methods are allowed.

[0058] In some embodiments, the current output from the welding gun to the workpiece is detected, and when determining whether arc initiation is successful by detecting the current, the preset current threshold can be configured to be greater than 0 A. For example, when the preset current threshold is configured to be 5 A, the current output from the welding gun to the workpiece is detected, and when the detected current is greater than or equal to 5 A, it is determined that arc initiation is successful.

[0059] It should also be noted that the process of detecting the voltage between the welding gun and the workpiece, and the process of detecting the current output from the welding gun to the workpiece, are not necessarily performed at the same time, but can be performed at different times; the two are not necessarily performed sequentially, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps, and the present application does not make specific limitations on this.

[0060] In some embodiments, after it is determined that arc striking is successful in step S200, arc striking current may be continuously provided until a preset time is reached, and then step S300 is executed to cut off the arc striking current.

[0061] In the above embodiment, after determining that the arc is successfully struck, the arc striking current is continuously provided and delayed for a period of time, thereby ensuring that the arc is completely stable and a reliable welding start condition is formed, avoiding welding defects or failures caused by arc instability (such as arc jumping, arc extinction, etc.). In addition, the continuous provision of the arc striking current can also avoid the situation where repeated arc striking is required due to incomplete initial arc, so it is also beneficial to improve welding efficiency and reduce welding wire waste.

[0062] In some embodiments, the preset time can be set to be greater than or equal to 100 μs; that is, after arc striking is successful, the arc striking current is continuously provided for at least 100 μs, and then the arc striking current is cut off. In this way, the continuity and stability of the arc striking process can be further ensured, and the risk of rework caused by arc striking interruption or arc instability can be reduced, thereby improving production efficiency and saving costs.

[0063] For step S300, specifically, after determining that the arc is successfully struck, the arc striking current can be gradually reduced until it is cut off, and the welding wire is pushed gradually close to the workpiece by the wire feeding mechanism, and finally the welding wire and the workpiece are in physical contact. When the welding wire touches the workpiece, a short circuit loop is formed between the welding wire and the workpiece, providing a path for subsequent welding current.

[0064] For example, in the short-circuit contact stage, dynamic adjustments can be made based on the short-circuit current and voltage monitored in real time to achieve short-circuit control. When it is detected that the short-circuit current is too large, the output current is appropriately reduced to prevent the welding wire from breaking due to overheating; when it is detected that the short-circuit current is insufficient, the current is appropriately increased to ensure that the short-circuit point can be melted quickly. In this way, it can ensure that the welding wire at the short-circuit point is quickly melted to form a molten droplet, and a stable welding arc is established between the workpiece.

[0065] After the short-circuit contact is complete, the welding device can be switched to welding current mode. At this point, the arc precisely enters a stable burning state.

[0066] Based on the same inventive concept, the embodiment of the present application also provides a welding device for metal arc gas welding (MIG). The welding device uses the arc starting method provided in the above embodiment to start the arc. The technical effects that can be achieved by the above arc starting method can also be achieved by the welding device, which will not be described in detail here. Moreover, the technical features between the method embodiment and the device embodiment can be replaced and supplemented with each other without conflict, so that those skilled in the art can understand the technical content of the present application.

[0067] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features of the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. An arc starting method for metal arc welding, characterized in that: include: Provide arc starting current to establish arc; The voltage between the welding gun and the workpiece is detected, and when the detected voltage is less than or equal to the preset voltage threshold, it is determined that the arc is successfully struck; and / or, detecting the current output from the welding gun to the workpiece, and determining that arc striking is successful when the detected current is greater than or equal to a preset current threshold; After determining that the arc striking is successful, the arc striking current is cut off.

2. The arc striking method according to claim 1, characterized in that: The providing of the arc striking current comprises: Obtain welding wire specifications and / or welding gas; The current value of the arc striking current is determined according to the welding wire specification.

3. The arc striking method according to claim 2, characterized in that: The welding wire specifications include welding wire diameter and / or welding wire material.

4. The arc striking method according to claim 1, characterized in that: The current value range of the arc striking current includes 30A to 200A.

5. The arc striking method according to claim 1, characterized in that: When detecting the current output from the welding gun to the workpiece, the preset current threshold is configured to be greater than 0A.

6. The arc striking method according to claim 1, characterized in that: After determining that the arc striking is successful, the arc striking current is continuously provided until a preset time is reached, and then the arc striking current is cut off.

7. The arc striking method according to claim 6, characterized in that: The preset time is greater than or equal to 100 μs.

8. The arc striking method according to claim 1, characterized in that: The providing of the arc striking current comprises: An arc-starting pulse is output to start an arc, and an oscillation frequency range of the arc-starting pulse includes 10kHz to 100MHz.

9. The arc striking method according to claim 1, characterized in that: The providing of the arc striking current comprises: An arc striking pulse is output to start an arc, and a voltage range of the arc striking pulse includes 1 kV to 1000 kV.

10. A welding device for metal arc welding, characterized in that: The welding equipment uses the arc starting method according to any one of claims 1 to 9 to start the arc.

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