Starting current control method, control terminal and mechanical argon arc welding machine

Abstract

The invention relates to a starting current control method, a control terminal and a mechanical argon arc welding machine. The method is used for the mechanical argon arc welding machine. The mechanical argon arc welding machine comprises an arc voltage tracking module, and the starting current control method comprises the steps that when the mechanical argon arc welding machine is started, the starting current of the mechanical argon arc welding machine is controlled to be increased from arcing current to set base value current; the starting current is kept as the set basic value current for a first set time, so that the arc voltage tracking module can perform effective arc voltage tracking work; and the starting current of the mechanical argon arc welding machine is controlled to be gradually increased to set welding pulse current from the set basic value current in a pulse mode. According to the technical scheme, the arc voltage tracking module carries out arc voltage tracking in advance, the problem that the air hole defect is likely to be generated in the welding starting stage is solved, and the welding quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of mechanized welding equipment and nuclear power plant pressure vessel welding, and in particular to a starting current control method, a control terminal and a mechanized argon arc welding machine. Background Art

[0002] At present, mechanized welding technology has been widely used in the field of pipeline welding in nuclear power plants. However, from the perspective of safety, nuclear power pipeline material characteristics and the particularity of the nuclear power environment, nuclear power plants have extremely high requirements for pipeline welding quality. For this reason, mechanized welding equipment (such as mechanized argon arc welding machines) are generally equipped with high-precision arc voltage tracking modules. The function of the arc voltage tracking module is to monitor and adjust the length of the welding arc in real time to ensure the stability of the molten pool during the welding process, thereby improving the welding quality and efficiency.

[0003] In the actual welding process, during the arc starting stage, the control of the arc starting current rising to the welding pulse current is very critical. Improper current control is one of the main factors leading to porosity defects, which in turn causes the welding quality to fail to meet the acceptance standards of nuclear power plants. In related technologies, a one-step rise method is often used from the arc starting current to the welding pulse current, that is, the arc starting current is directly increased in a pulsed manner to the welding pulse current set by the process, and arc length tracking is started after the rise is completed. This will cause the arc voltage tracking module to start welding before it has time to complete the control of the arc length. When the arc length is too long, there is a greater probability of arc keyholes. If the bottom of the arc keyhole is not closed normally, porosity defects will be formed inside the weld, seriously affecting the welding quality. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a starting current control method, a control terminal and a mechanized argon arc welding machine.

[0005] The technical solution adopted by the present invention to solve the technical problem is: constructing a starting current control method for a mechanized argon arc welding machine, the mechanized argon arc welding machine includes an arc voltage tracking module, and the starting current control method includes:

[0006] When the mechanized argon arc welding machine is started, the starting current of the welding machine is controlled to increase from the arc starting current to the set base value current;

[0007] Keeping the starting current at the set base current for a first set time, so that the arc voltage tracking module can effectively carry out arc voltage tracking work;

[0008] The starting current of the mechanized argon arc welding machine is controlled to gradually increase from the set base current to the set welding pulse current in a pulse form.

[0009] Preferably, the step of controlling the starting current of the mechanized argon arc welding machine to increase from the arc starting current to the set base current comprises:

[0010] Within a second set time, the starting current of the mechanized argon arc welding machine is controlled to increase linearly from the arc starting current to the set base current.

[0011] Preferably, the second set time ranges from 1 second to 3 seconds.

[0012] Preferably, the step of controlling the starting current of the mechanized argon arc welding machine to gradually increase from the set base current to the set welding pulse current in a pulse form comprises:

[0013] Determine and set the peak current according to the peak value of the welding pulse current;

[0014] During the third set time, the starting current of the mechanized argon arc welding machine is controlled to change from constant current output to pulse output, wherein the pulse valley value is the set base current, and the pulse peak value gradually increases from the set base current to the set peak current.

[0015] Preferably, the third set time ranges from 2 seconds to 5 seconds.

[0016] Preferably, the first set time ranges from 1 second to 3 seconds.

[0017] Preferably, the starting current control method further includes:

[0018] The set base current and the set welding pulse current are set according to the operation of the human-machine interaction device.

[0019] Preferably, the starting current control method further includes:

[0020] Calculate the ratio of the set base current to the set peak current;

[0021] Determining whether the ratio is within a set range;

[0022] When the ratio is not within the set range, a prompt signal is outputted to indicate that there is a risk of setting an error in the set base current or the set welding pulse current.

[0023] The present invention also constructs a control terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned starting current control method when executing the computer program.

[0024] The present invention also constructs a mechanized argon arc welding machine, comprising:

[0025] Arc voltage tracking module; and the control terminal mentioned above.

[0026] The implementation of the present invention has the following beneficial effects: a starting current control method is provided, by increasing the starting current from the arc starting current to the set base current and maintaining the first set time, so that the arc voltage tracking module starts the arc voltage tracking work, and then the starting current is increased from the set base current to the set welding pulse current, so that the arc voltage tracking module can promptly start the arc voltage tracking function in the current rising stage, solve the problem of easy generation of pore defects in the welding startup stage, effectively inhibit the generation of pores, improve the welding quality and efficiency, and play a positive role in improving the welding reliability of key equipment in nuclear power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0028] Figure 1 is a flowchart of a method for controlling a starting current to suppress the generation of pores in one embodiment of the present invention;

[0029] Figure 2 It is the starting current variation curve of the mechanized argon arc welding machine at the time of starting in the prior art;

[0030] Figure 3 is a weld distribution diagram of a narrow gap weld of a thick-walled pipe in one embodiment of the present invention;

[0031] Figure 4 It is a starting current variation curve of a mechanized argon arc welding machine when starting in one embodiment of the present invention;

[0032] Figure 5 is a circuit structure block diagram of a control terminal in one embodiment of the present invention;

[0033] Figure 6 It is a circuit structure block diagram of a mechanized argon arc welding machine in one embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0035] It should be noted that the flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor do they have to be executed in the order described. For example, some operations / steps can be decomposed, while some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0036] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0037] Figure 1 The program flow chart of a starting current control method for suppressing the generation of pores in one embodiment of the present invention is shown. The starting current control method is applied to a control terminal in a mechanized argon arc welding machine. By controlling the starting current rising process of the mechanized argon arc welding machine at the time of starting, the arc voltage tracking module in the mechanized argon arc welding machine can realize arc voltage tracking during the starting current rising process. Compared with the prior art, the arc voltage tracking module can control the arc length in advance, thereby solving the problem of pore defects that are easily generated in the welding starting stage.

[0038] In addition, the mechanized argon arc welding machine is an existing welding equipment in nuclear power plants. The mechanized argon arc welding machine should include a control terminal, an arc voltage tracking module, a high-frequency high-voltage generator and a pulse circuit, etc. The functions of other specific components and related components can refer to the prior art and will not be repeated here. The main improvement of the present invention is to optimize the starting current rising process of the mechanized argon arc welding machine.

[0039] See also Figure 1 The starting current control method for suppressing the generation of pores may include step S1, step S2 and step S3.

[0040] Step S1 includes: when the mechanized argon arc welding machine is started, controlling the starting current of the mechanized argon arc welding machine to increase from the arc starting current to the set base current.

[0041] Figure 2 This is the starting current variation curve of the mechanized argon arc welding machine when it is started in the prior art. Figure 2 After the existing mechanized argon arc welding machine is started, its starting current will be controlled in the form of pulse current, and it will increase rapidly from the arc starting current Q1 to the set welding pulse current E1 in one step, and then the welding work will be carried out. Since the pulse current increases rapidly during the growth of the starting current, the existing arc voltage tracking module can only realize arc voltage tracking when the current is relatively stable. If the pulse current is in the changing stage, the arc voltage tracking will not be possible, and the arc length cannot be accurately controlled. The role of this step is to abandon the current control mode of rapid increase in one step, so that the arc length tracking can be started during the current rising process.

[0042] In one embodiment, the starting current of the mechanized argon arc welding machine can be controlled to increase from the arc starting current to the set base current in the following manner: within the second set time, the starting current of the mechanized argon arc welding machine is controlled to increase linearly from the arc starting current to the set base current.

[0043] In one embodiment, the second set time may range from 1 second to 3 seconds. Specifically, the staff may operate the human-machine interaction device to set the second set time according to the needs, and the second set time generally increases with the increase of the set base current. Of course, the second set time may be fixed to 3 seconds.

[0044] Step S2 includes: keeping the starting current at the set base current for the first set time, so that the arc voltage tracking module can effectively carry out the arc voltage tracking work. It can be understood that when the starting current is kept at the set base current and lasts for the first set time, it means that the starting current will remain relatively stable for a certain period of time, that is, the arc voltage tracking module can track the starting current at this time, that is, the arc voltage tracking module can realize arc voltage tracking at this time, so as to control the arc length in advance, thereby avoiding the generation of pores due to the long arc length.

[0045] In one embodiment, the first set time may range from 1 second to 3 seconds. Specifically, the staff may operate the human-machine interaction device to set the first set time according to the needs, and the first set time generally increases with the increase of the set welding pulse current. Of course, the first set time may be fixed to 3 seconds to ensure that the arc voltage tracking module can achieve arc voltage tracking.

[0046] Step S3 includes: controlling the starting current of the mechanized argon arc welding machine to gradually increase from the set base current to the set welding pulse current in the form of pulses. After step S2, since the arc voltage tracking module is already able to track the arc voltage, it should be noted that the process of the starting current of the mechanized argon arc increasing from the arc starting current to the set base current is a DC output, and the process of the starting current increasing from the set base current to the set welding pulse current is a pulse output. Since the pores are caused by the long arc length, and in the pulse current increase stage (the pulse current increase stage refers to the stage in which the starting current increases from the set base current to the set welding pulse current), only the pulse peak current increases slowly, and the pulse base current remains constant. At this time, the arc voltage tracking module is in a normal working state, and the arc length is continuously in a controlled state. Therefore, this step can ensure that the arc voltage tracking module can implement arc voltage tracking during the entire second stage, so that there is no risk of pore formation during the process.

[0047] In one embodiment, the starting current of the mechanized argon arc welding machine can be gradually increased from the set base current to the set welding pulse current in the form of pulses in the following manner: the set peak current is determined according to the wave crest of the welding pulse current (that is, the wave crest current of the welding pulse current is set to the set peak current); within the third set time, the starting current of the mechanized argon arc welding machine is controlled to change from DC output to pulse output, wherein the pulse valley value is fixed to the set base current, and the pulse peak value is gradually increased from the set base current to the set peak current. Since the existing arc voltage tracking module realizes arc voltage tracking by detecting the valley arc voltage of the pulse current output by the mechanized argon arc welding machine, it can be understood that this example fixes the valley current of the pulse current output by the mechanized argon arc welding machine to the set base current, and the peak current of the pulse current will gradually increase with time, that is, in the pulse current increase stage, the valley current of each cycle of the pulse current is fixed, and this design is to improve the arc voltage tracking stability and reliability of the arc voltage tracking module, and the peak current of each cycle of the pulse current gradually increases until it increases to equal the set welding pulse current to meet the welding pulse current requirements. It should be noted that the valley current of the pulse current refers to the minimum current in each cycle of the pulse current, that is, the valley current.

[0048] In one embodiment, the third set time may range from 2 seconds to 5 seconds. Specifically, the staff may operate the human-machine interaction device to set the third set time according to the needs, and the third set time is positively correlated with the current difference between the set welding pulse current and the set base current.

[0049] In one embodiment, the starting current control method for suppressing the generation of pores can set the base current and the welding pulse current by performing the following steps: setting the base current and the welding pulse current according to the operation of the human-computer interaction device. The human-computer interaction device includes but is not limited to a mouse, a keyboard, a touch screen, a mobile terminal, etc.

[0050] Figure 3 10 is the root weld (including 1 fusion weld and multiple support welds), 20 is the filler weld, 30 is the final filler weld, and 40 is the cap weld. Figure 3 Different weld types have different sizes or volumes. Therefore, when welding corresponding welds, the weld width and thickness are also different, resulting in different settings for the welding pulse current. The first setting time and the setting base current are generally positively correlated with the setting welding pulse current. Usually, the size of the setting welding pulse current is positively correlated with the volume of the weld. Figure 3 Taking the embodiment as an example, the relationship between the first set time, the set base current and the set welding pulse current is explained.

[0051] Figure 3 The pipe size of the thick-walled pipe narrow gap weld shown is Ф904 (outer diameter) * 72mm (thickness). The first set time, set base current and set welding pulse current corresponding to the support weld, filling weld and cap weld can refer to Table 1:

[0052] Weld bead type First setting time Setting welding pulse current Set base current First support weld pass 1s 215±5A 80±5A Second support weld pass 1s 240±10A 120±10A Third support weld 1s 250±10A 130±10A Fourth support weld 2s 260±10A 150±10A First fill pass 3s 280±10A 180±20A Second fill pass 3s 300±15A 190±10A Third fill pass 3s 310±10A 200±10A Filling final weld 3s 270±20A 170±20A Cover weld 2s 240±10A 120±10A

[0053] As can be seen from Table 1, the set base current and the first set time increase approximately with the increase of the set welding pulse current. Among them, since the longitudinal height of the support weld and the filling weld is large, layered welding is required, and the support weld includes a first support weld, a second support weld, a third support weld, and a fourth support weld distributed layer by layer from bottom to top, and the filling weld 20 includes a first filling weld, a second filling weld, a third filling weld, etc. distributed layer by layer from bottom to top.

[0054] In order to facilitate the staff to accurately set the first setting time, the base current setting and the welding pulse current, in one embodiment, the starting current control method may further include: displaying a parameter setting recommendation table through a display device; wherein the parameter setting recommendation table includes a plurality of welding pulse current settings, and a plurality of first setting times and a plurality of base current settings corresponding to each welding pulse current setting. It can be understood that Figure 3 For example, the terminal can be controlled to display the contents of Table 1 through the display device to guide the staff to set the corresponding parameters when welding the relevant weld types. It should be noted that the setting of the welding pulse current is generally determined by the staff based on the actual situation of the welded workpiece on site and based on experience, and the setting of the base current and the first setting time can be determined by referring to the parameter setting recommendation table (such as Table 4).

[0055] In one embodiment, the starting current control method may further include the following steps: calculating the ratio of the set base current to the set welding pulse current; determining whether the ratio is within the set range; when the ratio is not within the set range, outputting a prompt signal indicating that there is a risk of setting an error in setting the base current or setting the welding pulse current. Furthermore, the prompt signal may be displayed by a display device to prompt the staff that the setting of the base current and / or the setting of the welding pulse current may be incorrect, thereby avoiding setting an inappropriate base current and setting a welding pulse current, which helps to improve welding quality.

[0056] It should be noted that the base current is set adaptively according to the size of the welding pulse current, because when the welding pulse current is set to be large and the base current is set to be small (that is, the ratio is small), it is easy to cause the weld to be narrow and the molten pool to be poor in stability, so that the weld is not formed or the edge is irregularly formed, and the layers are not fused, resulting in a decrease in welding quality. When the welding pulse current is set to be small and the base current is set to be large (that is, the ratio is large), the risk of uncontrolled weld formation will increase due to the high molten pool temperature, and arc pits and weld nodules will often appear. In addition, the heat input will be too large due to the large current, which will reduce the overall performance of the weld.

[0057] In one embodiment, the ratio of the set base current to the set welding pulse current may range from 0.34 to 0.7.

[0058] Figure 4 This is a starting current variation curve of a mechanized argon arc welding machine when starting up in one embodiment of the present invention. Figure 4 , implement the technical scheme of the present invention, by increasing the starting current from the arc starting current Q1 to the set base current H1, and maintaining the first set time, so that the arc voltage tracking module can start the arc voltage tracking work, and then increase the starting current from the set base current H2 to the set welding pulse current E1, so that the mechanized argon arc welding machine can start welding work, and realize the arc voltage tracking module to start arc voltage tracking in advance, solve the problem of easy generation of porosity defects in the welding startup stage, improve the welding quality and efficiency, and play a positive role in improving the reliability of nuclear power plant equipment.

[0059] Figure 5 It is a circuit structure block diagram of a control terminal in an embodiment of the present invention. The control terminal may include a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the starting current control method for suppressing the generation of pores provided in the embodiment of the present invention are implemented.

[0060] Figure 6 The circuit structure block diagram of a mechanized argon arc welding machine in one embodiment of the present invention, the mechanized argon arc welding machine may include an arc voltage tracking module and a control terminal provided by an embodiment of the present invention. Of course, the mechanized argon arc welding machine also includes other necessary welding machine components, such as a high-frequency high-voltage generator and a pulse circuit.

[0061] like Figure 6As shown, in one embodiment, the mechanized argon arc welding machine may further include a human-machine interaction device and a display device. The human-machine interaction device is used to output a control instruction capable of setting the first setting time, the second setting time, the third setting time, the base current setting, and the welding pulse current according to the operation of the staff. The display device is used to display the parameter setting recommendation table and / or the prompt signal output by the control terminal.

[0062] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0063] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0064] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0065] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. A starting current control method for a mechanized argon arc welding machine, wherein the mechanized argon arc welding machine includes an arc voltage tracking module, characterized in that: The starting current control method comprises: When the mechanized argon arc welding machine is started, the starting current of the welding machine is controlled to increase from the arc starting current to the set base value current; Keeping the starting current at the set base current for a first set time, so that the arc voltage tracking module can effectively carry out arc voltage tracking work; The starting current of the mechanized argon arc welding machine is controlled to gradually increase from the set base current to the set welding pulse current in a pulse form.

2. The starting current control method according to claim 1, characterized in that: The step of controlling the starting current of the mechanized argon arc welding machine to increase from the arc starting current to the set base current comprises: Within a second set time, the starting current of the mechanized argon arc welding machine is controlled to increase linearly from the arc starting current to the set base current.

3. The starting current control method according to claim 2, characterized in that: The second set time ranges from 1 second to 3 seconds.

4. The starting current control method according to claim 1, characterized in that: The step of controlling the starting current of the mechanized argon arc welding machine to gradually increase from the set base current to the set welding pulse current in a pulse form comprises: Determine and set the peak current according to the peak value of the welding pulse current; During the third set time, the starting current of the mechanized argon arc welding machine is controlled to be changed from DC output to pulse output, wherein the pulse valley value is the set base current, and the pulse peak value gradually increases from the set base current to the set peak current.

5. The starting current control method according to claim 4, characterized in that: The third set time ranges from 2 seconds to 5 seconds.

6. The starting current control method according to claim 1, characterized in that: The first set time ranges from 1 second to 3 seconds.

7. The starting current control method according to any one of claims 4 to 6, characterized in that: Also includes: The set base current and the set welding pulse current are set according to the operation of the human-machine interaction device.

8. The starting current control method according to claim 7, characterized in that: Also includes: Calculate the ratio of the set base current to the set peak current; Determining whether the ratio is within a set range; When the ratio is not within the set range, a prompt signal is outputted to indicate that there is a risk of setting an error in the set base current or the set welding pulse current.

9. A control terminal, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the starting current control method according to any one of claims 1 to 8 are implemented.

10. A mechanized argon arc welding machine, characterized in that: include: Arc voltage tracking module; and The control terminal as claimed in claim 9.

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