Welding control method and welding device
By dynamically adjusting the current value during the wire reheating stage and controlling the power in response to droplet shedding, the problems of wire sticking and arc breakage during welding are solved, ensuring stable arc length and improving welding quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-04-14
AI Technical Summary
In existing technologies, welding is prone to backfire, arc breakage, or wire sticking, and the wire tip is prone to forming molten droplet balls that affect the quality of subsequent welding.
By acquiring the speed decrease trend during the wire reheating stage, the current value is dynamically adjusted to match the wire feed speed, and the power output is turned off in response to the droplet falling off, thus controlling the ball cutting process.
It effectively avoids wire sticking, wire tipping, or arc breakage, ensures stable arc length, improves welding voltage stability, and prevents molten droplets at the wire tip from affecting subsequent welding.
Smart Images
Figure CN121847901A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of welding technology, and in particular to a welding control method and welding apparatus. Background Technology
[0002] In gas shielded welding, the power output is not immediately shut off when welding stops. Generally, two more stages are required: reheating and ball-cutting. The reheating stage involves the welding power source outputting a certain amount of energy to the welding wire as the welding period is about to end, reheating the slowly fed wire to maintain a certain distance between the wire and the welding material, preventing abnormalities such as wire sticking. The ball-cutting stage, after reheating, involves controlling the welding current to remove small balls formed by untransferred molten droplets at the wire tip, thereby improving the success rate of the next arc ignition and the quality of the arc ignition point.
[0003] However, in existing technologies, a fixed reheating time, current, and voltage are typically set during the reheating stage. Different reheating parameters need to be adjusted under different operating conditions, and the same parameters do not produce consistent results each time, easily leading to wire sticking, wire breakage, or arc interruption. Furthermore, during the ball-cutting stage, one or more precisely calculated current pulses are usually applied to actively and forcibly separate the molten droplets at the wire tip. However, this method easily causes shrinkage cavities on the surface of the workpiece to be welded, and because successful droplet separation cannot be guaranteed, small droplet balls easily form at the wire tip, affecting subsequent welding. Summary of the Invention
[0004] This application provides a welding control method to solve problems such as arc breakage due to backburning or wire sticking, and welding small balls with long welding wire ends in the prior art.
[0005] This application provides a welding control method, including: acquiring the decreasing trend of the welding wire speed from the start of reheating to the stop of welding wire feeding during the welding wire reheating stage; acquiring the decreasing trend of the current required during the welding wire reheating stage based on the decreasing trend of the welding wire speed; and assigning the current value required at different times during the welding wire reheating stage based on the decreasing trend of the current; and turning off the power output in response to the shedding of molten droplets at the end of the welding wire during the welding wire ball-cutting stage.
[0006] The steps for obtaining the wire speed decrease trend during the wire reheating stage from the start of reheating to the stop of wire feeding include: obtaining the speed attenuation parameter of the motor feeding the wire, the current wire feeding speed, and the offset coefficient; calculating the difference between the product of the speed attenuation parameter and the current wire feeding speed and the offset coefficient to obtain the wire feeding time, so as to obtain the wire feeding speed curve, and obtaining the wire speed decrease trend based on the wire feeding speed curve.
[0007] The steps for obtaining the decreasing trend of the current required during the wire reheating stage based on the decreasing trend of the welding wire speed, and for assigning the required current values at different times during the wire reheating stage based on the decreasing current trend, include: calculating the wire feeding distance by multiplying the wire feeding speed, wire feeding time, and distance coefficient at the start of wire reheating; obtaining the melting coefficient of the welding wire; calculating the ratio of the wire feeding distance to the product of the melting coefficient and the wire feeding time to obtain the average current of the welding wire during the reheating stage; obtaining the initial current of the welding wire at the start of reheating during the wire reheating stage; calculating the difference between the product of the current coefficient and the average current and the initial current to obtain the final current when the wire feeding stops, thus obtaining the current decay curve of the welding wire; and based on the current decay curve of the welding wire, obtaining the decreasing trend of the current required by the welding wire, and assigning the required current values at different times during the wire reheating stage based on the decreasing current trend.
[0008] The steps for obtaining the melting coefficient of the welding wire include: obtaining the diameter and material of the welding wire, and deriving the melting coefficient of the welding wire based on the diameter and material of the welding wire.
[0009] The steps of obtaining the decreasing trend of the current required during the wire reheating stage based on the decreasing trend of the welding wire speed, and giving the current value required at different times during the wire reheating stage based on the decreasing trend of the current, further include: obtaining the set voltage, actual voltage and arc stability coefficient of the welding wire during the reheating stage; calculating the voltage error by calculating the difference between the set voltage and the actual voltage, and obtaining the required compensation current by calculating the product of the voltage error and the arc stability coefficient.
[0010] The step of shutting off the power output in response to the shedding of molten droplets at the end of the welding wire during the wire ball-cutting stage includes: providing the welding wire with the required current to form a distinct molten droplet transition morphology, so that the welding wire forms a distinct molten droplet transition morphology.
[0011] The step of shutting off power output in response to the shedding of molten droplets at the end of the welding wire during the wire shearing stage includes: acquiring two consecutive voltage values during the wire shearing stage, and calculating the slope value of the voltage curve during the wire shearing stage based on the two voltage values; comparing the slope value with a slope threshold, and if the slope value is greater than the slope threshold, shutting off power output; if the slope value is less than the slope threshold, then performing the step of acquiring two consecutive voltage values during the wire shearing stage and calculating the slope value of the voltage curve during the wire shearing stage based on the two voltage values; and after a preset time, if the slope value is always less than the slope threshold, then shutting off power output.
[0012] The step of obtaining two consecutive voltage values during the wire shaving stage and deriving the slope of the voltage curve during the wire shaving stage based on the two voltage values includes: obtaining the first voltage value and the first time corresponding to the first voltage value during the wire shaving stage, and the second voltage value and the second time corresponding to the second voltage value; and obtaining the slope value by calculating the ratio of the difference between the second voltage value and the first voltage value to the difference between the second time and the first time.
[0013] The step of obtaining two consecutive voltage values during the wire shaving stage and deriving the slope of the voltage curve during the wire shaving stage based on the two voltage values further includes: obtaining the sampling period and continuously obtaining two connected voltage values during the wire shaving stage based on the sampling period.
[0014] To address the aforementioned problems, this application also provides a welding apparatus that performs welding control according to any of the above-mentioned methods.
[0015] The beneficial effects of this application are as follows: This application obtains the decreasing trend of the welding wire speed during the reheating stage from the start of reheating to the stop of wire feeding. Based on the decreasing trend of the welding wire speed, the decreasing trend of the current required by the welding wire during the reheating stage can be derived. Thus, when the welding wire is fed slowly, the melting rate of the welding wire corresponds to the feeding rate of the welding wire, thereby avoiding situations such as welding wire sticking, wire tipping, or arc breakage. It can also ensure that the welding wire extension length is consistent after each welding, that is, ensure the stability of the arc length, and thus ensure the stability of the welding voltage. Based on this, in response to the droplet falling off the welding wire end during the ball-cutting stage, the power output is turned off, which can effectively control the ball-cutting process and effectively avoid the formation of small droplet balls at the welding wire end, so as not to affect subsequent welding. Attached Figure Description
[0016] Figure 1 This is a schematic flowchart of an embodiment of the welding control method of this application; Figure 2 yes Figure 1 A flowchart illustrating an embodiment of step S11; Figure 3 yes Figure 1 A flowchart illustrating step S12 of the first embodiment; Figure 4 yes Figure 1 A flowchart illustrating step S12 of the second embodiment; Figure 5 yes Figure 1 A flowchart illustrating an embodiment of step S13; Figure 6 yes Figure 5 A flowchart of an embodiment of step S132. Detailed Implementation
[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0018] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.
[0019] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.
[0020] Please see Figure 1 , Figure 1 This is a schematic flowchart of an embodiment of the welding control method provided in this application. It should be noted that if substantially the same result is achieved, the method of this application is not necessarily identical. Figure 1 The illustrated process sequence is limited. For example... Figure 1 As shown, the method includes the following steps: S11: Obtain the decreasing trend of the welding wire speed from the start of reheating to the stop of wire feeding during the wire reheating stage.
[0021] It should be noted that welding includes a welding stage and a reheating stage. Before welding, the components to be welded need to undergo pre-welding treatment, i.e., the welding stage. Near the end of the welding process, the welding wire needs to be reheated to ensure a high weld yield. At the end of the welding process, the reheating stage begins. At the start of the reheating stage, wire feeding is stopped, and the wire feeding speed slowly decreases to zero. During this process, the welding wire is slowly fed to the welding point of the component to be welded. The reheating process occurs during this slow wire feeding, creating a certain distance between the welding wire and the component to be welded, thus preventing abnormalities such as wire sticking during subsequent welding.
[0022] In an optional embodiment, when welding is about to be completed, i.e., when entering the reheating stage, the decreasing trend of the welding wire speed during the reheating stage, from the start of reheating to the cessation of wire feeding, can be obtained. That is, during the reheating stage, to ensure that a certain distance is maintained between the welding wire tip and the base material at the end of welding, and to avoid situations such as wire tipping or sticking, the wire feeding speed no longer increases at the beginning of the reheating stage, but gradually decreases until it stops completely; it is fed slowly during the reheating process. During the slow wire feeding, the initial wire speed and the time taken from the start of the reheating stage to the cessation of wire feeding can be obtained, thus acquiring the wire speed curve and determining the decreasing trend of the welding wire speed.
[0023] S12: Based on the decreasing trend of the welding wire speed, obtain the decreasing trend of the current required during the welding wire reheating stage, and based on the decreasing trend of the current, give the current value required at different times during the welding wire reheating stage.
[0024] In an optional embodiment, after obtaining the decreasing trend of the welding wire speed, the required current value at different times during the reheating stage can be given based on the decreasing trend of the current required during the reheating stage. That is, during the reheating stage, the decreasing trend of the required current is derived based on the decreasing trend of the welding wire speed, thereby providing the corresponding current value when the welding wire is slowly fed in. Since the voltage fluctuates around the set voltage due to the instability of the operating conditions when welding the component, a corresponding compensation current is needed when providing the required current value at different times during the reheating stage to avoid arc fluctuations affecting the welding process.
[0025] In this embodiment, during the reheating stage, after obtaining the decreasing trend of the current required for the welding wire, i.e., when the welding wire is fed slowly, on the one hand, it can effectively avoid the situation where the decreasing trend of the wire feeding speed is greater than the decreasing trend of the welding current, that is, the melting speed of the welding wire is greater than the wire feeding speed, thereby avoiding the occurrence of arc interruption during welding. On the other hand, it can effectively avoid the situation where the decreasing trend of the welding wire speed is less than the decreasing trend of the welding current, that is, the melting speed of the welding wire is less than the wire feeding speed, thereby avoiding wire sticking or wire breakage. Based on this, the decreasing trend of the welding wire speed is used to derive the decreasing trend of the current required for the welding wire, and the current value required for different moments in the reheating stage is given based on the current decreasing trend. That is, the current value required for different moments in the reheating stage is given based on the decreasing trend of the welding wire speed, which can ensure that the melting speed of the welding wire is the same as the wire feeding speed, effectively avoiding the situation where the melting speed of the welding wire and the wire feeding speed are not corresponding, thereby avoiding the occurrence of arc interruption, wire sticking, and wire breakage caused by this.
[0026] S13: Power output is turned off in response to the shedding of molten droplets at the tip of the welding wire during the wire cutting stage.
[0027] It should be noted that during welding, the ball-cutting stage begins immediately after the reheating stage. In other words, the welding process includes the welding stage, the reheating stage, and the ball-cutting stage. After the welding stage, the reheating stage begins, and after the reheating stage, the ball-cutting stage begins.
[0028] In an optional embodiment, after the reheating stage ends, i.e. when the wire feeding stops, the wire enters the ball-cutting stage, which removes the small balls formed by the untransferred molten droplets at the end of the wire, thereby improving the success rate of the next arc ignition and the quality of the arc ignition point.
[0029] In this embodiment, when the wire feeding stops, the small balls formed by the transition droplets at the end of the wire need to be shaped. That is, when the droplets at the end of the wire are shaped, the power output is turned off in response to the droplets falling off the end of the wire, so as to avoid the formation of small droplet balls at the end of the wire again. That is, when the reheating stage ends and the shaving stage begins, the power output can be turned off directly after the droplets at the end of the wire fall off.
[0030] In an optional embodiment, during the reheating stage, the decreasing trend of the current required during the reheating stage can be derived based on the decreasing trend of the wire feed speed. Based on this decreasing trend, the current values required at different times during the reheating stage can be given, thereby ensuring that the wire feed speed and the wire melting speed remain consistent. Consequently, when the wire enters the ball-cutting stage after passing through the reheating stage, the distance between the wire tip and the part to be welded can be kept relatively stable, thus ensuring the stability of the arc length and the stability of the welding voltage. Based on this, the ball-cutting process can be effectively controlled when entering the ball-cutting stage.
[0031] Please refer to the following: Figure 2 , Figure 2 yes Figure 1 A flowchart illustrating an embodiment of step S11. Specifically, step S11 may further include the following steps: S111: Obtain the speed attenuation parameters of the motor feeding the welding wire, the current wire feeding speed, and the offset coefficient.
[0032] In one optional embodiment, the welding wire is fed by a motor, i.e., the wire feeding speed. During the reheating stage, the decreasing trend of the wire feeding is related to the motor parameters; that is, different motors have different parameters. Based on this, the speed attenuation parameters of the wire feeding motor, the current wire feeding speed, and the offset coefficient can be obtained.
[0033] S112: The wire feeding time is obtained by calculating the difference between the product of the speed attenuation parameter and the current wire feeding speed and the offset coefficient, so as to obtain the wire feeding speed curve of the welding wire, and the speed decrease trend of the welding wire is obtained based on the wire feeding speed curve.
[0034] In an optional embodiment, after obtaining the speed attenuation parameters of the wire feeding motor, the current wire feeding speed, and the offset coefficient, the wire feeding speed curve can be calculated, and the wire speed decrease trend can be obtained from the wire feeding speed curve. Specifically, the wire feeding time can be calculated, that is, the time taken from the start of reheating to the stop of wire feeding in the reheating stage, T=K*S1-B. Wherein, T represents the time taken from the start of reheating to the stop of wire feeding in the reheating stage, K represents the speed attenuation parameter of the motor, S1 represents the current wire feeding speed, and B represents the offset coefficient.
[0035] In this embodiment, by obtaining the wire feeding speed at the start of the reheating stage, the wire feeding speed at which the wire feeding stops, and the time taken from the start of the reheating stage to the stop of the wire feeding, a wire feeding speed curve can be obtained, and the decreasing trend of the wire speed can be obtained based on the wire feeding speed curve.
[0036] Please refer to the following: Figure 3 , Figure 3 yes Figure 1 A flowchart illustrating the first embodiment of step S12. Specifically, step S12 may further include the following steps: S121: The wire feeding distance is obtained by calculating the product of the wire feeding speed at the start of wire reheating, the wire feeding time, and the distance coefficient.
[0037] In an optional embodiment, the wire feeding speed at the start of the welding wire reheating can be obtained in advance. Then, the product of the wire feeding speed at the start of the reheating, the wire feeding time, and the distance coefficient is calculated to obtain the wire feeding distance L = L1(S2*T). Here, L represents the wire feeding distance, S2 represents the wire feeding speed at the start of the reheating, T is the time taken from the start of the reheating to the stop of the wire feeding, and L1 represents the distance coefficient, which can specifically be 0.5, i.e., the wire feeding distance L = 0.5(S2*T). Based on this, the wire feeding distance can be calculated.
[0038] The wire feeding distance is the same as the wire melting distance, that is, the wire feeding distance is equal to the wire melting distance.
[0039] S122: Obtain the melting coefficient of the welding wire.
[0040] In this embodiment, the melting coefficient of the welding wire is obtained. Specifically, the type parameters of the welding wire can be obtained in advance, including the diameter and material of the welding wire, so as to obtain the melting coefficient of the welding wire based on the diameter and material of the welding wire.
[0041] S123: The average current of the welding wire during the reheating stage is obtained by calculating the ratio of the wire feeding distance to the product of the melting coefficient and the wire feeding time.
[0042] In an optional embodiment, after obtaining the melting coefficient of the welding wire, the wire feeding distance can be calculated, and the average current value of the welding wire during the reheating stage can be obtained by dividing the distance by the product of the melting coefficient and the wire feeding time. Specifically, A1 = L / (M*T), where A1 represents the average current value of the welding wire during the reheating stage, L is the wire feeding distance, M represents the melting coefficient of the welding wire (where M is an empirical value obtained based on parameters such as the diameter and material of the welding wire), and T is the time taken from the start of reheating to the stop of wire feeding during the reheating stage. Based on this, the average current of the welding wire during the reheating stage can be calculated.
[0043] S124: Obtain the initial current of the welding wire at the start of the reheating stage.
[0044] Furthermore, the starting current of the welding wire during the reheating stage can be collected when the welding stage is about to end, that is, when the reheating stage begins.
[0045] S125: The final current when the wire feeding stops is obtained by calculating the difference between the product of the current coefficient and the average current and the starting current, so as to obtain the current decay curve of the welding wire.
[0046] In an optional embodiment, the final current A2 when the wire feeding stops during the reheating stage is A2 = CA1 - A3, where C represents the current coefficient, A1 represents the average current value of the welding wire during the reheating stage, and A3 represents the initial current of the welding wire at the start of the reheating stage. Specifically, the current coefficient C can be 2, meaning the final current is A2 = 2A1 - A3. Specifically, during the reheating stage, A1*T = 0.5(A3 + A2)*T, thus obtaining the final current value A2 when the wire feeding stops.
[0047] In this embodiment, by obtaining the last current value A2 when the wire feeding stops, the starting current A3 of the wire during the reheating stage, and the time T taken from the start of reheating to the stop of wire feeding during the reheating stage, the current decay curve of the wire can be obtained.
[0048] S126: Based on the current decay curve of the welding wire, the decreasing trend of the current required for the welding wire is obtained, and based on the decreasing trend of the current, the current value required at different times in the welding wire reheating stage is given.
[0049] In an optional embodiment, after obtaining the current decay curve of the welding wire, the decreasing trend of the current required by the welding wire can be derived from the current decay curve, and the required current value at different times during the welding wire reheating stage can be given based on the decreasing current trend. That is, the decreasing trend of the welding wire speed is used to derive the decreasing trend of the current required by the welding wire, and the required current value at different times during the welding wire reheating stage can be given based on the decreasing current trend. In other words, the current value at different times during the welding wire reheating stage can be given based on the decreasing trend of the welding wire speed. This can ensure that the melting rate of the welding wire is the same as the wire feeding rate, which can effectively avoid the situation where the welding wire melting rate and the wire feeding rate are not corresponding, resulting in arc interruption, wire sticking, and wire ejection.
[0050] Please refer to the following: Figure 4 , Figure 4 yes Figure 1 A flowchart illustrating the second embodiment of step S12. Specifically, step S12 may further include the following steps: S221: Obtain the set voltage, actual voltage, and arc stability coefficient of the welding wire during the reheating stage.
[0051] It should be noted that the voltage is set to a constant value during the reheating stage, i.e., the set voltage. However, due to the instability of the operating conditions when welding the parts to be welded, the voltage will fluctuate around the set voltage, i.e., the actual voltage. Based on this, the set voltage, actual voltage, and arc stability coefficient of the welding wire can be collected during the reheating stage.
[0052] S222: The voltage error is calculated by the difference between the set voltage and the actual voltage, and the required compensation current is obtained by multiplying the voltage error by the arc stability coefficient.
[0053] In an optional embodiment, after obtaining the set voltage, actual voltage, and arc stability coefficient of the welding wire, the compensation current for maintaining arc stability during the reheating stage can be determined. Specifically, the compensation current A4 = U1 * N, where U1 represents the voltage error and N represents the arc stability coefficient. The arc stability coefficient is preferably 11. In other embodiments, it can be set to other values according to different working conditions and different welding wires, such as 10, 12, etc., which are not specifically limited here. The voltage error U1 = U2 - U3, where U2 represents the set voltage and U3 represents the actual voltage.
[0054] In this embodiment, after obtaining the voltage error, a compensation current A4 for maintaining arc stability during the reheating stage can be derived based on the voltage error. This allows for the corresponding power output of the welding wire, preventing arc instability. Specifically, during the reheating stage, based on the decreasing speed trend of the welding wire, the required current value is provided to the welding wire at different times during the reheating stage. Furthermore, to ensure arc stability, corresponding current compensation can be provided to the welding wire.
[0055] Please refer to the following: Figure 5 , Figure 5 yes Figure 1 A flowchart illustrating an embodiment of step S13. Specifically, step S13 may further include the following steps: S131: The current required to form a distinct droplet transition morphology on the welding wire.
[0056] In this embodiment, at the end of the reheating stage, that is, when the welding wire stops and the welding wire speed decreases to zero, the end of the reheating stage is followed by the ball-cutting stage. When entering the ball-cutting stage, the output current value can be switched to a current segment that can clearly form a droplet transition at the end of the welding wire, that is, to provide the welding wire with the current required to form a clear droplet transition shape, so that the welding wire end begins to form droplets.
[0057] S132: Obtain two consecutive voltage values during the wire cutting stage, and calculate the slope of the voltage curve during the wire cutting stage based on the two voltage values.
[0058] In this embodiment, when the wire feeding stops, the small balls formed by the molten droplets at the end of the wire that have not yet transitioned need to be shaped. During the shaped ball shaping process, the voltage value of the wire can be obtained twice consecutively during the shaping stage. Based on the two consecutive voltage values, the voltage curve of the wire during the shaping stage can be obtained, and then the slope value of the voltage curve during the shaping stage can be obtained.
[0059] S133: Compare the slope value with the slope threshold. If the slope value is greater than the slope threshold, then turn off the power output.
[0060] In an optional embodiment, after obtaining the slope value of the voltage curve of the welding wire during the ball-cutting stage, the slope value can be compared with a preset threshold. If the slope value is greater than the slope threshold, the power output is turned off.
[0061] In this embodiment, as the molten droplet at the end of the welding wire gradually forms, the distance between the welding wire end and the part to be welded gradually shortens, causing the welding wire voltage to gradually decrease. As the molten droplet at the end of the welding wire gradually increases in size, and as it drips, the distance between the welding wire end and the part to be welded increases, causing the welding wire voltage to surge. Therefore, after the molten droplet at the end of the welding wire drips, due to the surge in welding wire voltage, the slope of the voltage curve derived from the two consecutive voltage values is not less than 5000. Conversely, as the molten droplet at the end of the welding wire gradually forms, the welding wire voltage gradually decreases, and the slope of the voltage curve is less than zero. Therefore, when determining whether the molten droplet at the end of the welding wire has dripped, specifically, if the slope of the voltage curve is greater than 1000, it can be determined that the molten droplet at the end of the welding wire has dripped; if the slope of the voltage curve is less than 1000, it can be determined that the molten droplet at the end of the welding wire is in the process of gradual formation. The slope threshold can be specifically 1000. In other embodiments, the slope threshold can also be 1000, 2000, 3000, etc. The specific value can be set according to the requirements. This application does not make any specific limitation here.
[0062] S134: If the slope value is less than the slope threshold, then execute the step of obtaining two consecutive voltage values in the wire cutting stage and obtaining the slope value of the voltage curve in the wire cutting stage based on the two voltage values.
[0063] In an optional embodiment, if the slope value is less than the slope threshold, it can be determined that the molten droplet at the end of the welding wire is in the process of gradual formation, that is, there is a molten droplet ball at the end of the welding wire. Based on this, it is necessary to perform the step of obtaining two consecutive voltage values during the ball-cutting stage of the welding wire, and obtaining the slope value of the voltage curve during the ball-cutting stage based on the two voltage values. That is, it is necessary to obtain two consecutive voltage values during the ball-cutting stage of the welding wire again, thereby obtaining the slope value of the voltage curve of the welding wire during the ball-cutting stage, and again determine the magnitude of the slope value and the slope threshold, and determine whether there is a molten droplet at the end of the welding wire.
[0064] S135: If the slope value remains less than the slope threshold after a preset time, the power output will be turned off.
[0065] In an optional embodiment, to avoid repeatedly detecting slope values that are less than the slope threshold, the power output of the welding wire can be directly shut off if the slope values are consistently less than the slope threshold within a preset time period. Specifically, the slope value of the voltage curve is continuously collected within the preset time period. If the slope value of the voltage curve is greater than the slope threshold within the preset time period, the power output can be directly shut off. If the slope values collected within the preset time period are all less than the slope threshold, that is, if the slope values collected within the preset time period are less than the slope threshold, the slope values are continuously collected until the preset time period is exceeded. After the preset time period is exceeded, the power output is directly shut off.
[0066] Please refer to the following: Figure 6 , Figure 6 yes Figure 5 A flowchart illustrating an embodiment of step S132. Specifically, step S132 may further include the following steps: S1321: Obtain the first voltage value and the first time corresponding to the first voltage value during the wire cutting stage, and the second voltage value and the second time corresponding to the second voltage value.
[0067] In this embodiment, after the current required for the formation of molten droplets is applied to the welding wire, the voltage value of the welding wire can be collected during the ball-cutting stage. When collecting the voltage value of the welding wire, the voltage value of the welding wire can be collected twice consecutively. The voltage values collected twice consecutively can be a first voltage value and a second voltage value. When collecting the first voltage value and the second voltage value, the first time corresponding to the collection of the first voltage value and the second time corresponding to the collection of the second voltage value can be obtained.
[0068] S1322: The slope value is obtained by calculating the ratio of the difference between the second voltage value and the first voltage value to the difference between the second time and the first time.
[0069] In an optional embodiment, after acquiring the first voltage value, the first time corresponding to the first voltage value, the second voltage value, and the second time corresponding to the second voltage value, the slope of the voltage curve during the chopping phase can be calculated. Specifically, k = (U B -U A ) / (t B -t A ), where U A Represented as the first voltage value, t A U represents the first time corresponding to the first voltage value. B Represented as the second voltage value, t B This represents the second time corresponding to the second voltage value.
[0070] In an optional embodiment, during the ball-cutting stage, after acquiring the voltage value of the welding wire twice consecutively and obtaining the slope value of the voltage curve during the ball-cutting stage, the slope value can be compared with a slope threshold to determine whether the molten droplet at the end of the welding wire has fallen. Specifically, as the molten droplet at the end of the welding wire falls, the distance between the end of the welding wire and the part to be welded increases, resulting in a sharp rise in the voltage value of the welding wire, thus indicating that the molten droplet at the end of the welding wire has fallen. If the slope value obtained from two consecutive voltage acquisitions is less than the slope threshold, the voltage value needs to be acquired twice more consecutively. The multiple acquisitions of two consecutive voltage values can be set as a cycle, i.e., a sampling cycle is set. After the first two consecutive voltage acquisitions show a slope value less than the slope threshold, the voltage value is acquired twice more consecutively according to the sampling cycle, until the slope value obtained from the two consecutive voltage acquisitions is greater than the slope threshold.
[0071] Based on the above inventive concept, this application also provides a welding apparatus, which is executed by the welding control method of any of the above embodiments.
[0072] Unlike existing technologies, the welding apparatus in this application obtains the decreasing trend of the welding wire speed during the reheating stage from the start of reheating to the cessation of wire feeding. Based on this decreasing trend, the decreasing trend of the current required for the welding wire during the reheating stage can be derived. This ensures that the melting rate of the welding wire corresponds to the feeding rate when the welding wire is fed slowly, thereby avoiding situations such as wire sticking, wire tipping, or arc breakage. It also ensures that the welding wire extension length is consistent after each welding operation, thus ensuring the stability of the arc length and consequently the stability of the welding voltage. Based on this, during the ball-cutting stage, in response to the molten droplet falling off the welding wire end, the power output is turned off, effectively controlling the ball-cutting process and preventing the formation of small molten droplet balls at the welding wire end, which could affect subsequent welding.
[0073] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.
Claims
1. A welding control method, characterized in that, The welding control method includes: The decreasing trend of the welding wire speed during the welding wire reheating stage, from the start of reheating to the cessation of welding wire feeding; Based on the decreasing trend of the welding wire speed, the decreasing trend of the current required in the welding wire reheating stage is obtained, and based on the decreasing trend of the current, the current value required at different times in the welding wire reheating stage is given. In response to the shedding of molten droplets from the end of the welding wire during the wire ball-cutting stage, the power output is turned off.
2. The welding control method according to claim 1, characterized in that, The step of obtaining the decreasing trend of the welding wire speed from the start of reheating to the stop of wire feeding during the welding wire reheating stage includes: Obtain the speed attenuation parameters of the motor feeding the welding wire, the current wire feeding speed, and the offset coefficient; The wire feeding time is obtained by calculating the difference between the product of the speed attenuation parameter and the current wire feeding speed and the offset coefficient, so as to obtain the wire feeding speed curve of the welding wire. The decreasing trend of the welding wire speed is derived from the wire feed speed curve of the welding wire.
3. The welding control method according to claim 2, characterized in that, The step of obtaining the decreasing trend of the current required during the wire reheating stage based on the decreasing trend of the welding wire speed, and assigning the current value required at different times during the wire reheating stage based on the decreasing trend of the current, includes: The wire feeding distance is obtained by calculating the product of the wire feeding speed at the start of the wire reheating, the wire feeding time, and the distance coefficient. Obtain the melting coefficient of the welding wire; The average current of the welding wire during the reheating stage is obtained by calculating the ratio of the wire feeding distance to the product of the melting coefficient and the wire feeding time. Obtain the initial current of the welding wire at the start of the reheating stage; The difference between the product of the current coefficient and the average current and the starting current is calculated to obtain the final current when the wire feeding stops, so as to obtain the current decay curve of the welding wire. Based on the current decay curve of the welding wire, the decreasing trend of the current required for the welding wire is obtained, and based on the decreasing trend of the current, the current value required at different times during the reheating stage of the welding wire is given.
4. The welding control method according to claim 3, characterized in that, The step of obtaining the melting coefficient of the welding wire includes: The diameter and material of the welding wire are obtained, and the melting coefficient of the welding wire is derived based on the diameter and material of the welding wire.
5. The welding control method according to claim 1, characterized in that, The step of obtaining the decreasing trend of the current required during the wire reheating stage based on the decreasing trend of the welding wire speed, and giving the current value required at different times during the wire reheating stage based on the decreasing trend of the current, further includes: The set voltage, actual voltage, and arc stability coefficient of the welding wire during the reheating stage are obtained. The voltage error is calculated by measuring the difference between the set voltage and the actual voltage, and the required compensation current is obtained by multiplying the voltage error by the arc stability coefficient.
6. The welding control method according to claim 1, characterized in that, The step of shutting off the power output in response to the shedding of molten droplets at the tip of the welding wire during the wire ball-cutting stage includes: The required current is applied to the welding wire to form a distinct droplet transition morphology, so that the welding wire forms a distinct droplet transition morphology.
7. The welding control method according to claim 1, characterized in that, The step of shutting off the power output in response to the shedding of molten droplets at the tip of the welding wire during the wire ball-cutting stage includes: Two consecutive voltage values are obtained during the wire shaving stage, and the slope of the voltage curve during the wire shaving stage is calculated based on the two voltage values. Compare the slope value with the slope threshold; if the slope value is greater than the slope threshold, then turn off the power output. If the slope value is less than the slope threshold, then the step of obtaining two consecutive voltage values in the welding wire ball-cutting stage and obtaining the slope value of the voltage curve in the welding wire ball-cutting stage based on the two voltage values is executed. If, after a preset time, the slope value remains less than the slope threshold, the power output is turned off.
8. The welding control method according to claim 7, characterized in that, The step of obtaining two consecutive voltage values during the wire shaving stage and deriving the slope of the voltage curve during the wire shaving stage based on the two voltage values includes: During the wire ball-cutting stage, obtain the first voltage value and the first time corresponding to the first voltage value, and the second voltage value and the second time corresponding to the second voltage value; The slope value is obtained by calculating the ratio of the difference between the second voltage value and the first voltage value to the difference between the second time and the first time.
9. The welding control method according to claim 7, characterized in that, The step of obtaining two consecutive voltage values during the wire shaving stage and deriving the slope of the voltage curve during the wire shaving stage based on the two voltage values further includes: Obtain the sampling period, and continuously obtain two consecutive voltage values during the wire cutting stage based on the sampling period.
10. A welding apparatus, characterized in that, The welding apparatus performs the welding control method according to any one of claims 1-9.