Control method of electric arc welding machine for steel structure welding

Abstract

The invention relates to the technical field of welding equipment, in particular to a control method of an electric arc welding machine for steel structure welding, in the welding process, the melting speed of a welding rod and the depth of a welding seam are obtained, according to the welding standard, the melting speed of the welding rod has a first preset interval, and the depth of the welding seam has a second preset interval; wherein when the melting speed of the welding rod is in the first preset interval and the depth of the welding seam is in the second preset interval, the welded piece which is welded at the moment meets the standard, and if the melting speed of the welding rod is not in the first preset interval or the depth of the welding seam is in the second preset interval, the welding piece is welded. And the heat input proportion of the welding rod and the weldment is adjusted through an adjusting program, the heat input sum of the welding rod and the weldment is adjusted, and it is ensured that the welded weldment meets the standard.

Description

Technical Field

[0001] The invention relates to the technical field of welding equipment, and in particular to a control method of an arc welding machine for steel structure welding. Background Art

[0002] As a key connection technology in the field of industrial manufacturing, welding achieves the combination of metal atoms through heating, high temperature or high pressure. Its process stability directly determines the product quality. There are many sources of energy for modern welding, including gas flame, arc, laser, electron beam, friction and ultrasound. During arc welding, the positive pole of direct current is connected to the workpiece or welding rod, and the negative pole of direct current is connected to the welding rod or workpiece. Continuously maintaining the positive or reverse connection of direct current will cause the welding rod or weldment to have too much concentrated heat input, which may cause the temperature gradient of the welding rod and weldment to be too large, causing local thermal stress concentration, resulting in welding rod spattering or excessive penetration, and even thermal cracks in the weld, which will damage the strength and reliability of the welded structure and make the welding quality substandard. Summary of the invention

[0003] The invention provides a control method for an arc welding machine for steel structure welding, so as to solve the problem of unstable welding quality during the welding process of a workpiece by an existing welding machine.

[0004] The control method of an arc welding machine for steel structure welding of the present invention adopts the following technical scheme: A control method for an arc welding machine for steel structure welding comprises the following steps: S100: Determine welding current and welding voltage; S200: obtaining the heat input ratio between the welding rod and the weldment; S300: obtaining the melting speed of the welding rod and the depth of the weld; S400: If the melting speed of the welding rod is not within the first preset range, and / or if the depth of the weld is not within the second preset range, an adjustment program is executed to adjust the heat input ratio of the welding rod and the weldment. At the same time, the adjustment program can adjust the total heat input of the welding rod and the weldment.

[0005] Furthermore, the adjustment procedure in step S400 is divided into a first adjustment procedure, a second adjustment procedure and a third adjustment procedure. The first adjustment procedure is used to adjust the heat input ratio of the welding rod and the weldment; the second adjustment procedure adjusts the total heat input of the welding rod and the weldment; the third adjustment procedure can adjust both the heat input ratio of the welding rod and the weldment and the total heat input of the welding rod and the weldment.

[0006] Furthermore, step S400 also includes: S410: If the melting speed of the welding rod is greater than the maximum value of the first preset interval and the depth of the weld is less than the minimum value of the second preset interval, or the melting speed of the welding rod is less than the minimum value of the first preset interval and the depth of the weld is greater than the maximum value of the second preset interval, then execute the first adjustment procedure to adjust the heat input ratio of the welding rod and the weldment.

[0007] Furthermore, step S400 also includes: S420: If the melting speed of the welding rod is greater than the maximum value of the first preset interval and the depth of the weld is greater than the maximum value of the second preset interval, or the melting speed of the welding rod is less than the minimum value of the first preset interval and the depth of the weld is less than the minimum value of the second preset interval, then execute the second adjustment procedure to adjust the total heat input of the welding rod and the weldment.

[0008] Furthermore, step S400 also includes: S430: If the melting speed of the welding rod is in the first preset interval, and the depth of the weld is greater than the maximum value of the second preset interval or less than the minimum value of the second preset interval, or, the melting speed of the welding rod is greater than the maximum value of the first preset interval or less than the minimum value of the first preset interval, and the depth of the weld is in the second preset interval, then execute the third adjustment procedure to first adjust the heat input ratio of the welding rod and the weldment, and then adjust the total heat input of the welding rod and the weldment.

[0009] Furthermore, in step S410, the first adjustment procedure includes: S411: Obtaining a DC connection mode between the weldment and the welding rod; S412: Control the total heat input to the welding rod and weldment to remain unchanged; S413: Adjust the time ratio of the AC connection and the DC connection between the weldment and the electrode.

[0010] Furthermore, in step S420, the second adjustment procedure includes: S421: Adjust the output voltage or output current of the welding power supply when welding the workpiece and the electrode.

[0011] Furthermore, in step S430, the third adjustment procedure includes: S431: adjusting the time ratio of the AC connection and the DC connection between the weldment and the welding rod; S432: Adjust the total heat input of the welding rod and the weldment according to the adjusted time ratio of the AC connection to the DC connection.

[0012] Furthermore, in step S300 , the melting speed of the welding rod and the depth of the weld are obtained through a distance sensor.

[0013] Furthermore, in step S100, an inverter is provided on the welding power source, and the inverter can change the output polarity of the welding power source and can also change the current mode of the welding power source output.

[0014] The beneficial effects of the present invention are as follows: when a control method of an arc welding machine for steel structure welding of the present invention is executed, the welding voltage and welding current of the initial welding power supply are first determined. During the welding process, the way in which the welding rod and the weldment are connected to the welding power supply can change the heat input ratio of the welding rod and the weldment. In conventional welding, a DC connection is usually used for welding, wherein when the positive electrode of the welding power supply is connected to the welding rod and the positive electrode is connected to the weldment, the heat input ratio of the welding rod and the weldment is different. During the welding process, the melting speed of the welding rod and the depth of the weld are obtained. According to the welding standard, the melting speed of the welding rod has a first preset interval, and the depth of the weld has a second preset interval. When the melting speed of the welding rod is in the first preset interval and the depth of the weld is in the second preset interval, the weldment completed at this time meets the standard. If the melting speed of the welding rod is not in the first preset interval, or the depth of the weld is in the second preset interval, the heat input ratio of the welding rod and the weldment is adjusted using an adjustment program, and the total heat input of the welding rod and the weldment is adjusted to ensure that the weldment completed by welding meets the standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 The present invention provides a flow chart of a control method of an arc welding machine for steel structure welding. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings). In the description of the present invention, it should be understood that the orientation or position relationship indicated by the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. are based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0019] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0020] like Figure 1 As shown, a control method of an arc welding machine for steel structure welding provided by an embodiment of the present invention comprises the following steps: S100: Determine welding current and welding voltage, wherein the output current of the welding power source is the welding current, and the output voltage of the welding power source is the welding voltage.

[0021] S200: Obtain the heat input ratio of the welding rod and the weldment. The heat input refers to the total energy of the electric energy in the welding power source delivered to the welding rod and the weldment during the welding process. When the direct current is positively connected, the heat input ratio of the welding rod and the weldment is generally 3:7; when the direct current is reversely connected, the heat input ratio of the welding rod and the weldment is generally 7:3; when the alternating current connects the welding rod and the weldment, the heat input ratio of the welding rod and the weldment is generally 1:1.

[0022] S300: Obtain the melting speed of the welding rod and the depth of the weld. The melting speed of the welding rod and the depth of the weld are obtained by a distance sensor. The welding rod is provided with a distance sensor, which is used to detect the length of the welding rod changed per unit time, thereby obtaining the melting speed of the welding rod. The melting speed of the welding rod is set as V a The weld position of the weldment is also equipped with a distance sensor, which can obtain the depth of the weld and set the depth of the weld to H. a .

[0023] S400: If the melting speed of the welding rod is not within the first preset range, or / and, if the depth of the weld is not within the second preset range, the adjustment program is executed to adjust the heat input ratio of the welding rod and the weldment, and the adjustment program can adjust the total heat input of the welding rod and the weldment. Specifically, during the welding process, the melting speed of the welding rod has a first preset range. When the melting speed of the welding rod is within the first preset range, the welding slag of the welding rod does not splash. The depth of the weld has a second preset range. When the depth of the weld is within the second preset range, the welded weldment is stable and reliable. The first preset range of the melting speed of the welding rod is defined as V min To V max The second preset interval of weld depth is set as H min To H max When the melting speed of the welding rod is not within the first preset range, the program needs to be adjusted to adjust the heat input ratio of the welding rod and the weldment, and the total heat input of the welding rod and the weldment; when the depth of the weld is not within the second preset range, the program needs to be adjusted to adjust the heat input ratio of the welding rod and the weldment, and the total heat input of the welding rod and the weldment. That is, according to the actual value V of the melting speed of the welding rod a The actual value of the weld depth H a Make a judgment and judge the inequality V min <V a <V max Is it true? At the same time, judge the inequality H min <H a <H max If one of the inequalities is not true or both inequalities are not true, the adjustment program is used to adjust the heat input ratio of the welding rod and the weldment, and the total heat input of the welding rod and the weldment is adjusted at the same time.

[0024] Specifically, the adjustment procedure in step S400 is divided into a first adjustment procedure, a second adjustment procedure and a third adjustment procedure. The first adjustment procedure is used to adjust the heat input ratio of the welding rod and the weldment; the second adjustment procedure adjusts the total heat input of the welding rod and the weldment; the third adjustment procedure can adjust both the heat input ratio of the welding rod and the weldment and the total heat input of the welding rod and the weldment.

[0025] In one embodiment, step S400 also includes: S410: If the electrode melting speed is greater than the maximum value of the first preset interval, and the weld depth is less than the minimum value of the second preset interval, in other words, the actually measured electrode melting speed V a >V max , and the actual measured weld depth H a <Hmin Or, the electrode melting speed is less than the minimum value of the first preset interval, and the depth of the weld is greater than the maximum value of the second preset interval. In other words, the actual measured electrode melting speed V a <V min , and the actual measured weld depth H a >H max If the melting speed of the welding rod and the depth of the weld meet the above two conditions, the first adjustment procedure is executed to adjust the heat input ratio of the welding rod and the weldment.

[0026] In this embodiment, the first adjustment procedure in step S410 includes: S411: Obtain the DC connection mode between the weldment and the welding rod. Before welding, connect the positive pole of the welding power source to the weldment or the welding rod. When the positive pole of the welding power source is connected to the weldment, the welding rod is connected to the negative pole of the welding power source. This is a DC positive connection. When the DC positive connection is used, the weldment is heated greatly, which is suitable for welding weldments with large thickness. When the negative pole of the welding power source is connected to the weldment, the welding rod is connected to the positive pole of the welding power source. This is a DC reverse connection. When the DC reverse connection is used, the weldment is heated less, which is suitable for welding weldments with small thickness.

[0027] S412: Control the total heat input to the welding rod and the weldment to remain unchanged. Ensure that the output voltage and output current of the welding power source remain unchanged, and the total output power of the welding power source remains unchanged. Under the premise that the way the weldment and the welding rod are connected to the welding power source remains unchanged, the total heat input of the welding rod and the heat input of the weldment remain unchanged.

[0028] S413: Adjust the time ratio of the AC connection and DC connection between the weldment and the welding rod. The welding power supply is provided with an inverter, which can change the output polarity of the welding power supply and the current output mode of the welding power supply. Specifically, the current output mode of the welding power supply is divided into DC and AC. When the welding power supply uses AC to connect the weldment and the welding rod, the heat input ratio of the welding rod to the weldment is 1:1. After the AC connects the weldment and the welding rod, the heat input ratio of the welding rod to the weldment changes. Under the premise that the total heat input of the welding rod and the weldment remains unchanged, the actual measured welding rod melting speed V a Compared with the actual measured weld depth H a changes, ensuring that V min <V a <V max Established, and H min <H a <H max Established to ensure that the completed welded parts meet the standards.

[0029] Furthermore, after the alternating current connects the weldment and the welding rod, the heat input ratio of the welding rod and the weldment changes. Within a unit time, the heat input ratio of the welding rod and the weldment during DC welding multiplied by the DC welding time, plus the heat input ratio of the welding rod and the weldment during AC welding multiplied by the AC welding time, equals the adjusted heat input ratio of the welding rod and the weldment multiplied by the unit time; during calculation, an adjusted heat input ratio of the welding rod and the weldment is preset, and the AC welding time is calculated based on the preset heat input ratio of the welding rod and the weldment, and a trial welding is performed based on the calculated time, and the melting speed V of the welding rod during welding is measured. a The depth of the weld H a , and judge the inequality V min <V a <V max With H min <H a <H max If not, a heat input ratio between the electrode and the weldment is preset again, and the process is repeated until V min <V a <V max With H min <H a <H max Established.

[0030] In one embodiment, step S400 also includes: S420: If the electrode melting speed is greater than the maximum value of the first preset interval, and the weld depth is greater than the maximum value of the second preset interval, in other words, the actually measured electrode melting speed V a >V max , and the actual measured weld depth H a >H max Or, the electrode melting speed is less than the minimum value of the first preset interval, and the depth of the weld is less than the minimum value of the second preset interval. In other words, the actual measured electrode melting speed V a <V min , and the actual measured weld depth H a <H min If the melting speed of the welding rod and the depth of the weld meet the above two conditions, the second adjustment procedure is executed to adjust the total heat input of the welding rod and the weldment.

[0031] In this embodiment, the second adjustment procedure in step S420 includes: S421: Adjust the output voltage or output current of the welding power source when the weldment and the electrode are welded. Under the premise that the way the weldment and the electrode are connected to the welding power source remains unchanged, the output voltage or output current of the welding power source is adjusted to change the sum of the heat input of the weldment and the heat input of the electrode during welding. The actual measured melting speed of the electrode Va The actual measured weld depth H a changes, ensuring that V min <V a <V max Established, and H min <H a <H max Established to ensure that the completed welded parts meet the standards.

[0032] In one embodiment, step S400 also includes: S430: If the electrode melting speed is within the first preset interval, and the weld depth is greater than the maximum value of the second preset interval or less than the minimum value of the second preset interval, in other words, the actual measured electrode melting speed makes V min <V a <V max The actual measured weld depth H a <H min or H a >H max Or, the electrode melting speed is greater than the maximum value of the first preset interval or less than the minimum value of the first preset interval, and the depth of the weld is in the second preset interval. In other words, the actual measured electrode melting speed V a <V min or V a >V max , and the actual measured weld depth makes H min <H a <H max If the melting speed of the welding rod and the depth of the weld meet the above two conditions, the third adjustment procedure is executed to first adjust the heat input ratio of the welding rod and the weldment, and then adjust the total heat input of the welding rod and the weldment.

[0033] In this embodiment, in step S430, the third adjustment procedure includes: S431: Adjust the time ratio of the AC connection to the DC connection between the weldment and the electrode. When DC welding is switched to AC welding, the heat input ratio between the weldment and the electrode will change. If the total heat input of the electrode and the weldment is not adjusted, the heat input of both the weldment and the electrode will change. The actual measured melting speed of the electrode V a Compared with the actual measured weld depth H aAll of them change. In unit time, the heat input ratio of the welding rod and the weldment in DC welding multiplied by the DC welding time, plus the heat input ratio of the welding rod and the weldment in AC welding multiplied by the AC welding time, is equal to the adjusted heat input ratio of the welding rod and the weldment multiplied by the unit time; an adjusted heat input ratio of the welding rod and the weldment is preset during calculation, and the AC welding time is calculated based on the preset heat input ratio of the welding rod and the weldment. In this process, the ratio of one of the welding rods or the weldment in the preset adjusted heat input ratio of the welding rod and the weldment remains unchanged. For example, when the heat input ratio of the welding rod and the weldment is 3:7 during DC connection, the preset adjusted heat input ratio of the welding rod and the weldment is 3:8.

[0034] S432: According to the adjusted time ratio of AC connection to DC connection, the total heat input of the welding rod and the weldment is adjusted. During DC welding, if the actual measured melting speed of the welding rod makes V min <V a <V max is established, or the actual measured weld depth makes H min <H a <H max If the heat input of qualified welding rods or weldments is established, the heat input of qualified welding rods or weldments is calculated according to the proportion of the total heat input of qualified welding rods or weldments, and then the adjusted heat input ratio of welding rods and weldments preset in step S431 is used to calculate the adjusted total heat input of welding rods and weldments. The time ratio of DC welding and AC welding calculated in step S431 is used, and the welding is attempted with the adjusted total heat input of welding rods and weldments calculated in step S432, and the melting speed V of welding rods during welding is measured. a The depth of the weld H a , and judge the inequality V min <V a <V max With H min <H a <H max If not, a heat input ratio between the electrode and the weldment is preset again, and the process is repeated until V min <V a <V max With H min <H a <H max Established.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A control method for an arc welding machine for steel structure welding, characterized in that: The following steps are involved: S100: Determine welding current and welding voltage; S200: obtaining the heat input ratio between the welding rod and the weldment; S300: obtaining the melting speed of the welding rod and the depth of the weld; S400: If the melting speed of the welding rod is not within the first preset range, and / or if the depth of the weld is not within the second preset range, an adjustment program is executed to adjust the heat input ratio of the welding rod and the weldment. At the same time, the adjustment program can adjust the total heat input of the welding rod and the weldment.

2. The control method of an arc welding machine for steel structure welding according to claim 1, characterized in that: The adjustment procedure in step S400 is divided into a first adjustment procedure, a second adjustment procedure and a third adjustment procedure. The first adjustment procedure is used to adjust the heat input ratio between the welding rod and the weldment. The second adjustment procedure adjusts the total heat input of the electrode and the weldment; The third adjustment program can adjust the heat input ratio of the welding rod and the weldment, and can also adjust the total heat input of the welding rod and the weldment.

3. The control method of an arc welding machine for steel structure welding according to claim 2, characterized in that: Step S400 also includes: S410: If the melting speed of the welding rod is greater than the maximum value of the first preset interval and the depth of the weld is less than the minimum value of the second preset interval, or the melting speed of the welding rod is less than the minimum value of the first preset interval and the depth of the weld is greater than the maximum value of the second preset interval, then execute the first adjustment procedure to adjust the heat input ratio of the welding rod and the weldment.

4. The control method of an arc welding machine for steel structure welding according to claim 2, characterized in that: Step S400 also includes: S420: If the melting speed of the welding rod is greater than the maximum value of the first preset interval and the depth of the weld is greater than the maximum value of the second preset interval, or the melting speed of the welding rod is less than the minimum value of the first preset interval and the depth of the weld is less than the minimum value of the second preset interval, then execute the second adjustment procedure to adjust the total heat input of the welding rod and the weldment.

5. The control method of an arc welding machine for steel structure welding according to claim 2, characterized in that: Step S400 also includes: S430: If the melting speed of the welding rod is in the first preset interval, and the depth of the weld is greater than the maximum value of the second preset interval or less than the minimum value of the second preset interval, or, the melting speed of the welding rod is greater than the maximum value of the first preset interval or less than the minimum value of the first preset interval, and the depth of the weld is in the second preset interval, then execute the third adjustment procedure to first adjust the heat input ratio of the welding rod and the weldment, and then adjust the total heat input of the welding rod and the weldment.

6. The control method of an arc welding machine for steel structure welding according to claim 3, characterized in that: In step S410, the first adjustment procedure includes: S411: Obtaining a DC connection mode between the weldment and the welding rod; S412: Control the total heat input to the welding rod and weldment to remain unchanged; S413: Adjust the time ratio of the AC connection and the DC connection between the weldment and the electrode.

7. The control method of an arc welding machine for steel structure welding according to claim 4, characterized in that: In step S420, the second adjustment procedure includes: S421: Adjust the output voltage or output current of the welding power supply when welding the workpiece and the electrode.

8. The control method of an arc welding machine for steel structure welding according to claim 5, characterized in that: In step S430, the third adjustment procedure includes: S431: adjusting the time ratio of the AC connection and the DC connection between the weldment and the welding rod; S432: Adjust the total heat input of the welding rod and the weldment according to the adjusted time ratio of the AC connection to the DC connection.

9. The control method of an arc welding machine for steel structure welding according to claim 1, characterized in that: In step S300 , the melting speed of the welding rod and the depth of the weld are obtained through a distance sensor.

10. The control method of an arc welding machine for steel structure welding according to claim 1, characterized in that: In step S100, an inverter is provided on the welding power source, and the inverter can change the output polarity of the welding power source and can also change the current mode of the welding power source output.

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