A method and system for controlling arc ignition in gas shielded arc welding

Abstract

The present disclosure proposes a method and system for arc striking control in gas shielded arc welding. The method is as follows: controlling the welding system to perform alternating movements of feeding and retracting the welding wire toward the parent material; when the parent material is in contact, the parent material is struck until a path is detected between the parent material and the welding wire; the welding wire is retracted once to detect whether the resistance between the parent material and the welding wire changes within a preset time. If so, the arc striking is successful; if not, the welding wire is retracted a second time, and the arc striking current between the parent material and the welding wire is increased, and the resistance is again detected to see if it changes; repeating the current steps until the arc striking is successful; retrieving the welding process database, matching the adjustment strategy according to the number of molten droplets at the current parent material, and adjusting the data of feed, retraction speed and current during the molten droplet transition until entering the normal welding stage. The present application improves the arc striking success rate, consistency and welding efficiency by means of striking, retracting, detecting whether the arc striking is successful and increasing the current.

Description

Technical Field

[0001] The present invention relates to the technical field of gas shielded welding, and in particular to a method and system for controlling arc striking in metal arc shielded welding. Background Art

[0002] With the development of industrial production and technological advancements, welding technology is increasingly being used in the manufacturing industry. Among them, MIG / MIG welding, as a highly efficient welding method with high welding speed and excellent welding quality, is widely used in welding various metal materials. In practical applications, the arc starting process of MIG / MIG welding has attracted widespread attention, and various industries are placing higher demands on the arc starting success rate, welding quality, and efficiency during MIG welding.

[0003] Currently, in the existing gas shielded welding process, the arc striking process mainly involves feeding the consumable electrode wire at a certain wire feeding speed, applying voltage between the wire and the workpiece to be welded, and after the two come into contact, the short-circuit current heats and melts the wire, ionizing the generated space and generating an arc, thereby striking the arc. However, this method has significant shortcomings: first, because the welding wire stores uncontrollable stress when it is fed and in contact with the base material, it may cause the welding wire to adhere to the base material, affecting the formation of the arc burning space and causing arc striking failure; second, when striking the arc, a large voltage and current are instantly generated, which heats the welding wire and base material to produce molten droplets and molten pools. At this time, it is very easy to produce large spatter due to the strong arc force. These problems will directly affect the welding quality and production cycle, reducing production efficiency.

[0004] Although the existing public technology has a solution to improve the arc striking success rate by coordinating wire feeding and retraction during the arc striking stage, it ignores the situation where the arc burning space cannot be generated if the bonding cannot be retracted, resulting in arc striking failure. It also does not take into account the consistency between the molten droplet transfer and the arc striking process, which are also important factors affecting the arc striking success rate and welding efficiency. Summary of the Invention

[0005] In response to the problems existing in the prior art, the present invention provides a method and system for controlling arc striking in a consumable electrode gas shielded welding process. The method, in the arc generation stage, ensures that the non-conductive film is broken through in a short time, a short circuit is caused, an arc is generated, and the non-conductive material is removed through the alternating movement of forward wire feeding and reverse retraction and knocking of the welding wire; in the arc striking stage, if arc striking failure is detected, the arc striking success rate is greatly improved by retraction and increasing the current; after the arc striking is successful, in order to maintain the stability of the arc burning space, in the droplet transition stage, the wire feed, retraction speed and the increase ratio of the current are adjusted to promote a smooth transition to the molten pool, avoid spattering and adhesion of the welding wire to the cold base material, and ensure the consistency of the droplet transition and arc striking process.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for controlling arc ignition in a metal arc welding process, comprising:

[0008] Controlling the welding system to alternately feed and retract the welding wire toward the parent material; upon contact with the parent material, repeating the alternating motion to strike the parent material until a path is detected between the parent material and the welding wire;

[0009] The welding wire is retracted once to detect whether the resistance between the base material and the welding wire changes within the preset time. If the resistance changes, the arc is struck successfully.

[0010] If the resistance does not change, the welding wire is retracted a second time and the arc striking current between the base material and the welding wire is increased to detect whether the resistance changes again. Repeat the current step until the arc is struck successfully.

[0011] The welding process database is retrieved, and the adjustment strategy is matched according to the number of molten droplets at the current base material. The data of wire feed, retraction speed and current during droplet transfer are adjusted until the normal welding stage is entered.

[0012] Preferably, when performing the alternating motion, the wire feeding speed is greater than the wire retracting speed.

[0013] Preferably, the knocking is used to knock off non-conductive substances on the end of the welding wire or the surface of the base material.

[0014] Preferably, the path current I1 detected when a path is generated between the base material and the welding wire satisfies 10A<I1<200A.

[0015] Preferably, the moving distances of the primary and secondary retractions are greater than the moving distance of the retraction in the alternating motion.

[0016] Preferably, the preset time T satisfies 0.5ms<T<2ms.

[0017] Preferably, the data in the welding process database is derived from historical welding data and includes multiple welding process data packets; the welding process data packets include the number of droplets and the corresponding arc current, dynamic change data of wire feed and retraction speed, and the duration of each action.

[0018] In a second aspect, the present invention provides a metal arc welding arc control system, comprising:

[0019] The arc generation module is used to control the welding system to perform alternating movements of feeding and retracting the welding wire toward the parent material; when the welding wire contacts the parent material, the alternating movement is repeated to strike the parent material until a path is detected between the parent material and the welding wire;

[0020] The arc striking module is used to retract the welding wire once and detect whether the resistance between the base material and the welding wire changes within a preset time. If the resistance changes, the arc striking is successful;

[0021] The arc striking module after failure is used to retract the welding wire for the second time if the resistance does not change, increase the arc striking current between the base material and the welding wire, and detect whether the resistance changes again; repeat the current step until the arc striking is successful;

[0022] The droplet transfer module is used to call the welding process database, match the adjustment strategy according to the number of droplets at the current base material, and adjust the data of wire feed, retraction speed and current during droplet transfer until entering the normal welding stage.

[0023] In a third aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for controlling arc ignition in a metal arc welding process described in the first aspect.

[0024] In a fourth aspect, the present invention provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the method for controlling arc ignition in a metallurgical gas shielded welding process described in the first aspect are implemented.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) Improve the arc striking success rate: The arc striking method of feeding the welding wire directly into the base material is abandoned. Instead, the welding wire is fed and retracted alternately. The fast and small-range back and forth movement of the welding wire avoids the welding wire from sticking to the base material, which is conducive to breaking through the non-conductive film and smoothly generating the arc burning space, thereby improving the arc striking success rate; and, after contacting the base material, the alternating movement is still repeated to form a knocking operation on the surface of the base material, thereby knocking out the non-conductive impurities that affect the welding quality, ensuring the stability of the welding process and improving the quality of the welded product.

[0027] (2) Maintaining the consistency of the arc striking process: During the transition from the arc striking stage to the normal welding process, the wire feed, retraction speed and current gradually increase according to the number of molten droplets, thereby ensuring the consistency of the entire arc striking process; and, in each feed and retraction cycle, it can smoothly transition to the molten pool, eliminating the splashing during the molten droplet transition, and ensuring the stability and safety of the arc striking process.

[0028] (3) Improve welding efficiency: By optimizing the arc striking control method, increasing the current between the welding wire and the base material, and providing conditions for arc stability, the number of arc striking failures can be reduced, thereby reducing the auxiliary time in the welding process and improving the overall welding efficiency.

[0029] (4) Enhanced welding quality: Due to the improvement of arc striking success rate, the stability and consistency of the welding process can be ensured, thereby improving the welding quality and meeting the welding needs of various industrial fields.

[0030] (5) Wide range of applications: The arc starting control method for metal arc welding proposed in the present invention is applicable to push-pull wire welding guns and ordinary welding guns, meeting the welding needs of factories of different sizes, and is applicable to the welding of various metal materials and their composite materials, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which constitute a part of the present disclosure, are used to provide a further understanding of the present disclosure. The exemplary embodiments of the present disclosure and their descriptions are used to explain the present disclosure but do not constitute a limitation of the present disclosure.

[0032] Figure 1 A flow chart of a method for controlling arc ignition in gas shielded arc welding provided by the present disclosure;

[0033] Figure 2 A schematic structural diagram of a welding device with a push-pull wire welding gun provided by the present disclosure;

[0034] Figure 3 An arc striking control timing diagram of the welding equipment with a push-pull wire welding gun provided by the present disclosure when arc striking is successful once;

[0035] Figure 4 A timing diagram of arc ignition control for a welding device with a push-pull wire welding gun provided by the present disclosure when arc ignition fails once;

[0036] Figure 5 A schematic structural diagram of a welding device with a common welding gun provided by the present disclosure;

[0037] Figure 6 The present invention provides a timing diagram of arc ignition control for welding equipment with a common welding gun. DETAILED DESCRIPTION

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0039] Technical term explanation:

[0040] (1) Gas Metal Arc Welding (GMAW): This refers to a welding method that uses the arc generated between the welding wire and the base material as a heat source to melt the metal. During the welding process, the arc melts the welding wire and the base material to form a molten pool and the weld area, which is protected by an inert gas or active gas, effectively preventing the harmful effects of the surrounding air.

[0041] (2) Arc striking: refers to the process of igniting the arc with welding materials (electrodes, wires, etc.) and creating an arc burning space to stabilize the arc during welding.

[0042] Example 1

[0043] like Figure 1 As shown, this embodiment discloses a method for controlling arc ignition in a metal arc welding process, comprising:

[0044] S1: Controlling the welding system to perform alternating movements of feeding and retracting the welding wire toward the base metal; upon contacting the base metal, repeating the alternating movements to strike the base metal until a path is detected between the base metal and the welding wire;

[0045] S2: The welding wire is retracted once to detect whether the resistance between the base material and the welding wire changes within the preset time. If the resistance changes, the arc is successfully struck.

[0046] S3: If the resistance does not change, the welding wire is retracted a second time and the arc striking current between the base material and the welding wire is increased to detect whether the resistance changes again. The current step is repeated until the arc is struck successfully.

[0047] S4: Retrieve the welding process database, match the adjustment strategy according to the number of droplets at the current base material, and adjust the data of wire feed, retraction speed and current during droplet transfer until entering the normal welding stage.

[0048] In this specific embodiment, the purpose of effectively improving the arc striking success rate, consistency and welding efficiency is achieved by alternating motion, knocking, retraction and increasing the current after detecting arc striking failure.

[0049] The method can be used for example Figure 2 The welding equipment with a push-pull wire welding gun shown in FIG. Figure 3 As shown:

[0050] S1 corresponds to the t0-t3 period in the early stage of arc ignition. At t1, the welding gun switch is turned on and the welding signal is given. At t2, the servo control receives the signal and the welding system performs alternating movements of feeding and retracting the welding wire toward the base material.

[0051] To ensure the wire is fed close to the base metal and avoid adhesion between the base metal and the wire, the maximum forward feed speed (v1) is slightly faster than the maximum reverse retraction speed (v2) (away from the base metal) until contact with the base metal is achieved before time t3; v1 < 30 m / s, v2 < 29 m / s, and v1 > v2. Simultaneously, after contact with the base metal, the wire is retracted, repeating this alternating motion several times on the base metal surface, similar to a tapping motion, to remove any non-conductive material that may be present on the wire end or base metal surface.

[0052] A path is created at time t3, preparing for arc striking.

[0053] S2 corresponds to the arc ignition phase, from t3 to t5. After the wire and base metal are connected, the wire undergoes a single reverse retraction process from t3 to t4. The distance of this retraction is greater than the distance of the retraction during the alternating motion. t3 is the moment when the wire and base metal circuit is established, the wire brakes, and retraction begins. t4 is the moment when the arc is detected. At this point, the arc ignition current rises to I1.

[0054] The preset time T is set in the range of 0.5ms<T<2ms. If t4-t3≤T and a change in the resistance between the base material and the welding wire is detected, the space created by the wire retraction is successfully ionized to generate an arc, i.e., arc initiation is completed at time t4; if t4-t3>T and no change in the resistance between the base material and the welding wire is detected, arc initiation is determined to have failed.

[0055] When arc ignition fails, that is, S3, such as Figure 4 As shown in the figure, the welding wire is retracted twice, and the arc striking current I2 between the base metal and the welding wire is increased, so that the current climbs from I1 to I2. This increases the arc striking current and improves the arc striking success rate. Among them, 10A < I1 < 200A, and 250A < I2 < 500A.

[0056] Check again whether the resistance changes. If not, repeat the current step until the arc is struck successfully.

[0057] It should be understood that the current data after the second retraction is obtained based on historical welding data.

[0058] Period t4-t5: Arc is struck successfully after retraction, and the first molten droplet is formed.

[0059] S4 is the droplet transfer phase, which transitions from the arc ignition stage to the normal welding process, corresponding to the time period t5-t6. The welding process database is retrieved and the adjustment strategy is matched based on the current number of droplets in the base metal. The wire feed, retraction speed, and current data during droplet transfer are adjusted until the normal welding stage begins.

[0060] The welding process database described in this embodiment is a relational database. The data in the welding process database comes from the arc ignition stage related data accumulated in historical welding activities, and includes multiple adjustment strategies; the adjustment strategies are data such as the dynamic change data of different numbers of molten droplets and the corresponding arcing current, wire feed and retraction speeds, and the duration of each action.

[0061] Preferably, in order to facilitate the application of the adjustment strategy, the speed data contained in the dynamically changing data is sorted from low to high; the adjustment strategy includes labels of wire feed and retraction speed, as well as the magnitude and duration of the increased current under the label.

[0062] In order to promote the smooth generation of the molten pool, avoid adhesion of the welding wire to the cold base material, and ensure the consistency of the arc striking process, this embodiment takes into account the dynamic adjustment of the adjustment strategy. With the help of the welding process database, the corresponding adjustment strategy is called according to the different numbers of molten droplets to improve the stability and safety of the arc striking process.

[0063] By t6, the droplet transfer is completed, a molten pool is formed, and the overall arc initiation stage is completed, followed by the normal welding stage.

[0064] The method described in this embodiment can also be used for Figure 5 The welding equipment with ordinary welding gun is shown in FIG. The cost of welding equipment with ordinary welding gun is relatively low, and small-scale factories usually use this welding equipment to reduce production and operation costs; this welding equipment has low sensitivity and cannot achieve high-speed retraction, such as Figure 6 As shown, the wire feeding speed in the t5-t6 period cannot be flexibly adjusted, but arc striking can still be achieved by the method described in this embodiment. Therefore, the method described in this embodiment has a wide range of applications and can provide high-quality welding support for various factories.

[0065] Compared with the existing technology, the arc striking control method for gas shielded arc welding provided by the present invention, in the arc generation stage, feeds the welding wire forward, retracts and strikes the welding wire in the reverse direction, so as to ensure that the non-conductive film is broken through in a short time, a short circuit is caused, and the non-conductive material is removed; in the arc striking stage, after detecting the arc striking failure, the arc striking success rate is greatly improved by retracting and increasing the current; after the arc striking is successful, in order to maintain the stability of the arc burning space to ensure the quality of the subsequent welding, in the transition stage from successful arc striking to normal welding, the data of the feed and retraction speed, current and time during the molten droplet transition are adjusted by calling the welding process database and intelligent matching adjustment strategy, so as to promote the gradual generation of the molten pool, avoid the adhesion of the welding wire to the cold base material, ensure the consistency of the arc striking process, and provide strong support for factories of different sizes to achieve high-quality welding.

[0066] Example 2

[0067] This embodiment provides a control system for arc ignition of a metal arc welding system, comprising:

[0068] Arc generation module: controls the welding system to alternately feed and retract the wire toward the base metal. When the wire contacts the base metal, the system repeats the alternating motion until a path is detected between the base metal and the wire.

[0069] Arc striking module: The welding wire is retracted once to detect whether the resistance between the base material and the welding wire changes within a preset time. If the resistance changes, the arc striking is successful.

[0070] Arc ignition module after failure: If the resistance does not change, the welding wire is retracted a second time, and the arc ignition current between the base material and the welding wire is increased to detect whether the resistance changes again; the current step is repeated until the arc is successfully ignited;

[0071] Droplet transfer module: retrieves the welding process database, matches the adjustment strategy according to the number of droplets at the current base material, and adjusts the wire feed, retraction speed and current data during droplet transfer until entering the normal welding stage.

[0072] Example 3

[0073] This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the steps of the method for controlling arc ignition in metal arc welding described in the first embodiment are implemented.

[0074] Compared with the existing technology, the arc striking control method for gas shielded arc welding provided by the present invention, in the arc generation stage, feeds the welding wire forward, retracts and strikes the welding wire in the reverse direction, so as to ensure that the non-conductive film is broken through in a short time, a short circuit is caused, and the non-conductive material is removed; in the arc striking stage, after detecting the arc striking failure, the arc striking success rate is greatly improved by retracting and increasing the current; after the arc striking is successful, in order to maintain the stability of the arc burning space to ensure the quality of the subsequent welding, in the transition stage from successful arc striking to normal welding, the data of the feed and retraction speed, current and time during the molten droplet transition are adjusted by calling the welding process database and intelligent matching adjustment strategy, so as to promote the gradual generation of the molten pool, avoid the adhesion of the welding wire to the cold base material, ensure the consistency of the arc striking process, and provide strong support for factories of different sizes to achieve high-quality welding.

[0075] Example 4

[0076] This embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of the method for controlling arc ignition in metal arc welding described in the first embodiment are implemented.

[0077] Compared with the existing technology, the arc striking control method for gas shielded arc welding provided by the present invention, in the arc generation stage, feeds the welding wire forward, retracts and strikes the welding wire in the reverse direction, so as to ensure that the non-conductive film is broken through in a short time, a short circuit is caused, and the non-conductive material is removed; in the arc striking stage, after detecting the arc striking failure, the arc striking success rate is greatly improved by retracting and increasing the current; after the arc striking is successful, in order to maintain the stability of the arc burning space to ensure the quality of the subsequent welding, in the transition stage from successful arc striking to normal welding, the data of the feed and retraction speed, current and time during the molten droplet transition are adjusted by calling the welding process database and intelligent matching adjustment strategy, so as to promote the gradual generation of the molten pool, avoid the adhesion of the welding wire to the cold base material, ensure the consistency of the arc striking process, and provide strong support for factories of different sizes to achieve high-quality welding.

[0078] The steps or modules involved in Examples 2 to 4 above correspond to those in Example 1. For detailed implementations, please refer to the relevant description of Example 1. The term "computer-readable storage medium" should be understood to mean a single medium or multiple media that includes one or more instruction sets; it should also be understood to include any medium that can store, encode, or carry an instruction set for execution by a processor and cause the processor to perform any method of the present invention.

[0079] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for controlling arc ignition in gas shielded arc welding, characterized in that: include: Control the welding system to alternately feed and retract the welding wire toward the base material; When the base metal is in contact, the alternating motion is still repeated to strike the base metal until a path is detected between the base metal and the welding wire; The welding wire is retracted once to detect whether the resistance between the base material and the welding wire changes within the preset time T. If the resistance changes, the arc is successfully struck. If the resistance does not change, the welding wire is retracted a second time, and the arc current between the base material and the welding wire is increased to check again whether the resistance changes. Repeat the current step until the arc is struck successfully; Retrieve the welding process database, match the adjustment strategy according to the current number of droplets at the base material, and adjust the wire feed, retraction speed and current data during droplet transfer until entering the normal welding stage; The path current generated by the detection of the path between the base material and the welding wire Meet 10A< <200A; The moving distances of the first and second retractions are greater than the moving distance of the retractions in the alternating motion; The data in the welding process database is derived from historical welding data and includes multiple adjustment strategies; the adjustment strategies include the number of droplets and the corresponding arc current, the dynamic change data of the wire feed and retraction speed, and the duration of each action; During the transition from the arc striking stage to the normal welding process, the wire feed, retraction speed and current gradually increase according to the number of molten droplets to ensure the consistency of the entire arc striking process; and a smooth transition to the molten pool is achieved in each feed and retraction cycle to prevent splashing during the molten droplet transition.

2. A method for controlling arc ignition in MIG / MAG welding according to claim 1, characterized in that: When performing the alternating motion, the wire feeding speed is greater than the wire retracting speed.

3. The method for controlling arc ignition in MIG / MAG welding according to claim 1, wherein: The knocking is used to knock off non-conductive substances on the end of the welding wire or the surface of the base material.

4. The method for controlling arc ignition in MIG / MAG welding according to claim 1, wherein: The preset time T satisfies 0.5ms<T<2ms.

5. A control system for arc starting of a metal arc welding, adopting a method for arc starting of a metal arc welding according to any one of claims 1 to 4, characterized in that: include: The arc generation module is used to control the welding system to alternately feed and retract the welding wire toward the base material; When the base metal is in contact, the alternating motion is still repeated to strike the base metal until a path is detected between the base metal and the welding wire; The arc striking module is used to retract the welding wire once and detect whether the resistance between the base material and the welding wire changes within a preset time T. If the resistance changes, the arc striking is successful; The arc striking module after failure is used to retract the welding wire for the second time if the resistance does not change, and increase the arc striking current between the base material and the welding wire to detect whether the resistance changes again; Repeat the current step until the arc is struck successfully; The droplet transfer module is used to call the welding process database, match the adjustment strategy according to the current number of droplets at the base material, and adjust the data of wire feed, retraction speed and current during droplet transfer until entering the normal welding stage.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of a method for controlling arc ignition in gas shielded arc welding according to any one of claims 1 to 4 are implemented.

7. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the method for controlling arc ignition of gas shielded arc welding according to any one of claims 1 to 4 are implemented.

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