Start current control method, control terminal and mechanized argon arc welding machine

Abstract

The present application relates to a starting current control method, a control terminal and a mechanized argon arc welding machine, and the method is used for the mechanized argon arc welding machine. The mechanized argon arc welding machine comprises an arc pressure tracking module, and the starting current control method comprises the following steps: when the mechanized argon arc welding machine starts, the starting current of the mechanized argon arc welding machine is controlled to increase from an arc starting current to a set base value current; the starting current is kept as the set base value current for a first set time, so that the arc pressure tracking module can develop effective arc pressure tracking work; and the starting current of the mechanized argon arc welding machine is controlled to gradually increase from the set base value current to a set welding pulse current in the form of pulses. The technical scheme of the present application realizes that the arc pressure tracking module develops arc pressure tracking in advance, solves the problem that pores are prone to be generated in the welding starting stage, and improves the welding quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mechanized welding equipment and nuclear power plant pressure vessel welding, and particularly relates to a starting current control method, a control terminal and a mechanized argon arc welding machine. BACKGROUND

[0002] At present, the mechanized welding technology has been widely applied in the field of pipeline welding in nuclear power plants, but considering the safety, the material characteristics of nuclear power pipelines and the particularity of the nuclear power environment, the nuclear power plant has very high requirements for the quality of pipeline welding, therefore, the mechanized welding machine equipment (such as the mechanized argon arc welding machine) is generally configured with a high-precision arc voltage tracking module. The function of the arc voltage tracking module is to monitor and adjust the length of the welding arc in real time, so as to ensure the stability of the molten pool in the welding process, thereby improving the welding quality and efficiency.

[0003] In the actual welding process, in the arc starting stage, the control of the increase of the arc starting current to the welding pulse current is very critical, and improper current control is one of the main factors leading to the generation of porosity defects, which in turn causes the welding quality to fail to meet the acceptance standards of the nuclear power plant. In the related technology, the arc starting current is directly increased to the welding pulse current in a one-stage manner, and after the increase is completed, the arc length tracking is started, which causes the arc voltage tracking module to start the welding operation before it completes the control of the arc length, and when the arc length is too long, there is a high probability of generating an arc spoon hole, and the bottom of the arc spoon hole is not normally closed, which will form a porosity defect in the weld, seriously affecting the welding quality. SUMMARY

[0004] The technical problem to be solved by the present application 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 application to solve the technical problem is: a starting current control method is constructed 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 increased from the arc starting current to a set base value current;

[0007] The starting current is maintained at the set base value current for a first set time, so that the arc voltage tracking module can effectively expand the arc voltage tracking work;

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

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

[0010] In a second set time, the starting current of the mechanized argon arc welding machine is controlled to linearly increase from the arc striking current to the set base value 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 from the set base value current to gradually increase to the set welding pulse current in a pulse form comprises:

[0013] A set peak value current is determined according to a wave crest of the welding pulse current;

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

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

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

[0020] A ratio of the set base value current to the set peak value current is calculated;

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

[0022] When the ratio is not within the set range, a prompt signal capable of indicating that there is a setting error risk of the set base value current or the set welding pulse current is output.

[0023] The application also constructs a control terminal comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the starting current control method when executing the computer program.

[0024] The application also constructs a mechanized argon arc welding machine comprising:

[0025] an arc voltage tracking module; and the control terminal described above.

[0026] The present application has the following beneficial effects: a starting current control method is provided, the starting current is first increased from an arc current to a set base value current and maintained for a first set time, the arc voltage tracking module is deployed for arc voltage tracking work, then the starting current is increased from the set base value current to a set welding pulse current, the arc voltage tracking module is timely deployed for arc voltage tracking function in the current rising stage, the problem of porosity defects in the welding starting stage is solved, the generation of porosity is effectively inhibited, the welding quality and efficiency are improved, and the welding reliability of key equipment in nuclear power plants is positively improved. BRIEF DESCRIPTION OF DRAWINGS

[0027] The present application will be further described below in conjunction with the drawings and embodiments, wherein:

[0028] Figure 1 is a program flow chart of the starting current control method for inhibiting the generation of porosity in an embodiment of the present application;

[0029] Figure 2 is a starting current variation curve of a mechanical argon arc welding machine in the prior art during starting;

[0030] Figure 3 is a welding pass distribution diagram of a thick-walled pipe narrow gap weld in an embodiment of the present application;

[0031] Figure 4 is a starting current variation curve of a mechanical argon arc welding machine in an embodiment of the present application during starting;

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

[0033] Figure 6 is a circuit structure block diagram of a mechanical argon arc welding machine in an embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to have a clearer understanding of the technical features, objects and effects of the present application, the specific embodiments of the present application will be described in detail with reference to the drawings.

[0035] It should be noted that the flow chart shown in the drawings is only illustrative, not necessarily including all the contents and operations / steps, and not necessarily executed in the described order. For example, some operations / steps can be further divided, and some operations / steps can be combined or partially combined, so the actual execution order can be changed according to the actual situation.

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

[0037] Figure 1 is a program flowchart of the starting current control method for suppressing the generation of pores in an embodiment of the present application. The starting current control method is applied to a control terminal in a mechanized argon arc welding machine, and by controlling the starting current rising process of the mechanized argon arc welding machine at the start, the arc voltage tracking module in the mechanized argon arc welding machine can realize arc length control during the starting current rising process. Compared with the prior art, the arc voltage tracking module can be controlled in advance, thereby solving the problem of easy generation of pores during the welding start stage.

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

[0039] Referring to Figure 1 , the starting current control method for suppressing the generation of pores can include steps S1, S2, and S3.

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

[0041] Figure 2 is the starting current change curve of the mechanized argon arc welding machine in the prior art at the start. Referring to Figure 2 , after the existing mechanized argon arc welding machine is started, the starting current is controlled in the form of pulse current to increase from the arc starting current Q1 to the set welding pulse current E1 in one segment, and then the welding work is carried out. Since the pulse current increases relatively fast 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 variation stage, arc voltage tracking cannot be performed, and the arc length cannot be accurately controlled. The role of the present step is to abandon the one-segment fast increasing current control mode, so that the arc length tracking is started during the rising process of the current.

[0042] In an 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 value 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 value current.

[0043] In one embodiment, the second set time can range from 1 second to 3 seconds. Specifically, the staff can operate the man-machine interaction device to set the size of 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 can be fixed at 3 seconds.

[0044] Step S2 includes maintaining the starting current at the set base current for a first set time, so that the arc voltage tracking module can effectively expand the arc voltage tracking work. It can be understood that when the starting current is maintained 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, thereby controlling the arc length in advance, and further avoiding the formation of pores due to the elongated arc length.

[0045] In one embodiment, the first set time can range from 1 second to 3 seconds. Specifically, the staff can operate the man-machine interaction device to set the size of 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 can be fixed at 3 seconds to ensure that the arc voltage tracking module can realize 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 can already track the arc voltage, it should be noted that the process of increasing the starting current of the mechanized argon arc from the arc current to the set base current is direct current output, and the process of increasing the starting current from the set base current to the set welding pulse current is pulse output. Since pores are generated due to the elongated arc length, and only the pulse peak current slowly increases while the pulse base current remains constant during the pulse current increase stage (the pulse current increase stage refers to the stage of increasing the starting current from the set base current to the set welding pulse current), 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 track the arc voltage during the entire second stage, so as to ensure 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 a set base current to a set welding pulse current in a pulse form by the following way: determining a set peak current according to the peak of the welding pulse current (i.e. setting the peak current of the welding pulse current as the set peak current); controlling the starting current of the mechanized argon arc welding machine to change from a direct current output to a pulse output within a third set time, wherein the pulse valley is fixed as the set base current and the pulse peak 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 arc voltage of the pulse current valley output by the mechanized argon arc welding machine, it can be understood that, in the present example, the pulse current valley output by the mechanized argon arc welding machine is fixed as the set base current, and the pulse current peak gradually increases over time, i.e. the valley current of each cycle of the pulse current is fixed in the pulse current increasing stage. Such design is to improve the stability and reliability of the arc voltage tracking module in arc voltage tracking, and the peak current of each cycle of the pulse current gradually increases until it equals the set welding pulse current to meet the welding pulse current requirement. It should be noted that the valley current of the pulse current refers to the minimum current of each cycle of the pulse current, i.e. the valley current.

[0048] In one embodiment, the third set time can range from 2 seconds to 5 seconds. Specifically, the operator can operate the human-computer interaction device to set the size of the third set time, 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 porosity can set the sizes of the set base current and the set welding pulse current by performing the following steps: setting the set base current and the set 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 is the weld bead distribution diagram of the thick-walled pipe narrow gap weld in one embodiment of the present application, 10 is the root bead (including one fusion bead and multiple support beads), 20 is the filler bead, 30 is the filler end bead, and 40 is the cover bead. Please refer to Figure 3 The sizes or volumes of different types of weld beads are different, so the weld bead width, thickness, and the set of the set welding pulse current are different when welding the corresponding weld bead. The first set time and the set base current are generally positively correlated with the set welding pulse current, and the size of the set welding pulse current is generally positively correlated with the volume of the weld bead. The relationship between the first set time, the set base current, and the set welding pulse current will be illustrated below by taking the embodiment as an example. Figure 3 ​

[0051] Figure 3 The pipe dimensions shown for the narrow gap weld in the thick-walled pipe are Ф904 (outer diameter) * 72mm (thickness). The first set time, set base current, and set welding pulse current corresponding to the support weld, filler weld, and capping weld, respectively, can be found in Table 1.

[0052]

[0053] As shown in Table 1, the set base current and the first set time generally increase with the increase of the set welding pulse current. Since the longitudinal height of the support weld and filler weld is relatively large, layered welding is required. 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. The filler weld 20 includes a first filler weld, a second filler weld, a third filler weld, etc., distributed layer by layer from bottom to top.

[0054] To facilitate accurate setting of the first preset time, the preset base current, and the preset welding pulse current by operators, in one embodiment, the starting current control method may further include: displaying a parameter setting recommendation table via a display device; wherein the parameter setting recommendation table includes multiple preset welding pulse currents, and multiple first preset times and multiple preset base currents corresponding one-to-one with each preset welding pulse current. It can be understood that... Figure 3 For example, the control terminal can display the contents of Table 1 on the display device to guide the staff in setting the corresponding parameters when welding 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 workpiece being welded on site and on experience, while 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 1).

[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 a set range; and outputting a prompt signal indicating a risk of incorrect setting of the base current or welding pulse current when the ratio is not within the set range. Furthermore, the prompt signal can be displayed on a display device to alert personnel that the setting of the base current and / or welding pulse current may be incorrect, thereby avoiding inappropriate setting of the base current and welding pulse current and helping to improve welding quality.

[0056] It should be noted that the base value current is set adaptively according to the size of the set welding pulse current, because when the set welding pulse current is large and the set base value current is small (i.e. the ratio is small), it is easy to cause the weld forming to be narrow, the molten pool stability to be poor, thus making the weld not to be formed or the edge to be irregularly shaped, the interlayer to be not fused, and the welding quality to be reduced. When the set welding pulse current is small and the set base value current is large (i.e. the ratio is large), it will cause the risk of weld forming out of control due to the molten pool temperature being too high to increase, and arc pits and welding tumor defects often occur. In addition, the heat input will be too large due to the large current, and the comprehensive performance of the weld will be reduced.

[0057] In one embodiment, the ratio of the set base value current to the set welding pulse current can be 0.34 to 0.7.

[0058] Figure 4 is a starting current change curve of the mechanized argon arc welding machine in the starting process in one embodiment of the present application. Please refer to Figure 4 The technical solution of the present application is implemented by increasing the starting current from the arc starting current Q1 to the set base value current H1 and keeping the first set time, enabling the arc voltage tracking module to expand the arc voltage tracking work, and then increasing the starting current from the set base value current H2 to the set welding pulse current E1, so that the mechanized argon arc welding machine can carry out welding work, and the arc voltage tracking module is enabled to expand the arc voltage tracking in advance, the problem of porosity defects easily occurring in the welding starting stage is solved, the welding quality and efficiency are improved, and the reliability of the nuclear power plant equipment is positively improved.

[0059] Figure 5 is a circuit structure block diagram of the control terminal in one embodiment of the present application. The control terminal can 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 porosity provided by the embodiment of the present application are implemented.

[0060] Figure 6 is a circuit structure block diagram of the mechanized argon arc welding machine in one embodiment of the present application. The mechanized argon arc welding machine can include an arc voltage tracking module and the control terminal provided by the embodiment of the present application. 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] As Figure 6As shown, in one embodiment, the mechanized argon arc welding machine can further include a human-machine interaction device and a display device. The human-machine interaction device is configured to output a control instruction capable of setting any parameter size of the first set time, the second set time, the third set time, the set base current and the set welding pulse current according to the operation of the worker. The display device is configured to display a parameter setting recommendation table and / or a prompt signal output by the control terminal.

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

[0063] The skilled person can further realize that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be realized by electronic hardware, computer software or a combination of both. In order to clearly illustrate the interchangeability of hardware and software, the components and steps of the examples have been described in a general manner in the above description. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0064] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein can be directly implemented by hardware, a software module executed by a processor, or a combination of both. The software module can 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 embodiments of the present application, and the description is more specific and detailed, but it should not be considered as a limitation on the scope of the patent of the present application. It should be noted that for those skilled in the art, the above technical features can be freely combined without departing from the concept of the present application, and some modifications and improvements can be made, which are all within the scope of protection of the present application. Therefore, any equivalent transformation and modification within the scope of the claims of the present application should be covered by the claims of the present application.

Claims

1. A start current control method for a mechanized argon arc welder, said mechanized argon arc welder comprising an arc pressure tracking module, characterized in that, The starting current control method comprises: controlling the starting current of the mechanical argon arc welding machine to increase from an arc starting current to a set base value current when the mechanical argon arc welding machine is started; maintaining the starting current as the set base value current for a first set time to enable the arc pressure tracking module to effectively perform arc pressure tracking work; controlling the starting current of the mechanical argon arc welding machine to gradually increase from the set base value current to a set welding pulse current in a pulse form; the step of controlling the starting current of the mechanical argon arc welding machine to gradually increase from the set base value current to a set welding pulse current comprises: determining a set peak value current according to a peak of the welding pulse current; controlling the starting current of the mechanical argon arc welding machine to change from direct current output to pulse output within a third set time, wherein a pulse valley value is the set base value current and a pulse peak value gradually increases from the set base value current to the set peak value current.

2. The start current control method according to claim 1, characterized by, the step of controlling the starting current of the mechanical argon arc welding machine to increase from an arc starting current to a set base value current comprises: controlling the starting current of the mechanical argon arc welding machine to linearly increase from the arc starting current to the set base value current within a second set time.

3. The start current control method according to claim 2, characterized by, the second set time ranges from 1 second to 3 seconds.

4. The start current control method according to claim 1, characterized by, the third set time ranges from 2 seconds to 5 seconds.

5. The start current control method of claim 1, wherein the first set time ranges from 1 second to 3 seconds.

6. The start current control method according to claim 4 or 5, characterized by, Further comprising: setting the set base value current and the set welding pulse current according to an operation of a human-computer interaction device.

7. The start current control method according to claim 6, characterized by, Further comprising: calculating a ratio of the set base value current to the set peak value current; judging whether the ratio is within a set range; when the ratio is not within the set range, outputting a prompt signal capable of indicating that there is a risk of setting error in the set base value current or the set welding pulse current.

8. A control terminal comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, the processor implements the steps of the starting current control method of any one of claims 1 to 7 when executing the computer program.

9. A mechanized argon arc welding machine characterized by, comprise: an arc pressure tracking module; and the control terminal of claim 8.

Images