Wire Feeding Motor Control Method, Circuit, Equipment and Computer Storage Medium for Electric Welding Machine

Abstract

The present invention relates to the field of power electronics technology, and discloses a control method, circuit, device and computer storage medium for a wire feeding motor of a welding machine. The method includes: obtaining switch information, determining a speed given signal based on the switch information, and controlling the wire feeding motor of the welding machine to work according to the speed given signal; collecting the power generation signal of the wire feeding motor of the welding machine based on a preset intermittent time, and comparing the power generation signal with the speed given signal to obtain comparison information; generating a control signal according to the comparison information, and controlling the wire feeding motor of the welding machine to work at a stable speed according to the control signal. The present invention reduces the control cost of the wire feeding motor on the premise of ensuring the wire feeding accuracy rate.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and in particular, to a control method, circuit, device and computer storage medium for a wire feeding motor of a welding machine. Background Art

[0002] With the rapid development of the wire feeding motor of the welding machine, users' requirements for the control of the wire feeding motor of the welding machine are also getting higher and higher. While hoping to meet the requirement of controlling the wire feeding motor of the welding machine to perform normal wire feeding, it is also necessary to ensure the control cost of the wire feeding motor during wire feeding control, which also puts forward higher requirements for the control of the wire feeding motor of the welding machine.

[0003] The traditional control method for the wire feeding motor of the welding machine is to add devices such as an optical code disk or a generating coil and a magnet on the rotating shaft of the motor to feedback the rotation speed of the motor, and adjust the driver in a timely manner through the feedback signal to stabilize the rotation speed of the motor. This control method for the wire feeding motor of the welding machine has great defects, and there is a problem that it is necessary to add devices such as an optical code disk or a generating coil and a magnet on the rotating shaft of the motor. That is, this control method for the wire feeding motor of the welding machine will increase the control cost of the wire feeding motor due to the need to add devices such as an optical code disk or a generating coil and a magnet on the rotating shaft of the motor. Summary of the Invention

[0004] The main object of the present invention is to provide a control method, circuit, device and computer storage medium for a wire feeding motor of a welding machine, aiming at the technical problem of how to reduce the control cost of the wire feeding motor on the premise of ensuring the wire feeding accuracy.

[0005] To achieve the above object, the present invention provides a control method for a wire feeding motor of a welding machine, and the control method for the wire feeding motor of the welding machine includes the following steps:

[0006] Obtain switch information, and determine a speed given signal based on the switch information, and control the wire feeding motor of the welding machine to work according to the speed given signal;

[0007] Collect the generated signal of the wire feeding motor of the welding machine based on a preset intermittent time, and obtain comparison information by comparing the generated signal with the speed given signal;

[0008] Generate a control signal according to the comparison information, and control the wire feeding motor of the welding machine to perform constant speed operation according to the control signal.

[0009] Optionally, the step of collecting the generated signal of the wire feeding motor of the welding machine based on a preset intermittent time includes:

[0010] Obtain working duration information, and detect whether the working time in the working duration information matches the preset intermittent time;

[0011] If the working time in the working duration information matches the preset interruption time, a power supply stop instruction is triggered, and power supply to the wire feeding motor of the electric welding machine is stopped based on the power supply stop instruction;

[0012] The wire feeding motor of the electric welding machine that stops power supply collects the working voltage as a power generation signal.

[0013] Optionally, the step of obtaining comparison information by comparing the power generation signal and the speed setting signal includes:

[0014] Determine the working voltage in the power generation signal, and detect whether the working voltage matches the set voltage of the speed setting signal;

[0015] If the working voltage does not match the set voltage of the speed setting signal, determine the voltage difference between the set voltage and the working voltage as the comparison information.

[0016] Optionally, the step of generating a control signal according to the comparison information includes:

[0017] Determine the voltage difference in the comparison information, and look up a table according to the voltage difference to determine the PWM wave pulse width control instruction corresponding to the difference in the comparison information;

[0018] Use the PWM wave pulse width control instruction as the control signal.

[0019] Optionally, after the step of using the PWM wave pulse width control instruction as the control signal, it includes:

[0020] Determine the pulse width correction instruction in the PWM wave pulse width control instruction, and perform pulse width correction on the preset output PWM wave according to the pulse width correction instruction;

[0021] Control the wire feeding motor of the electric welding machine based on the corrected preset output PWM wave, and execute the step of obtaining the collected power generation signal based on the preset interruption time.

[0022] In addition, to achieve the above object, the present invention also provides a control circuit for the wire feeding motor of an electric welding machine. The control circuit for the wire feeding motor of the electric welding machine is applied to the control method for the wire feeding motor of the electric welding machine. The control circuit for the wire feeding motor of the electric welding machine includes a setting module, an MCU module, a driving circuit, a braking circuit, and a motor circuit;

[0023] The MCU module is respectively connected to the setting module, the driving circuit, the braking circuit, and the motor circuit. The MCU module is used to collect the power generation signal of the motor circuit, determine the comparison information corresponding to the power generation signal and the setting signal of the setting module, and generate a control signal according to the input switch information and the comparison information;

[0024] The driving circuit is respectively connected to the braking circuit and the motor circuit, and the driving circuit is used to control the wire feeding motor of the electric welding machine to work according to the control signal;

[0025] The braking circuit is connected to the motor circuit, and the braking circuit is used to control the motor circuit to brake and stop working according to the control signal.

[0026] Optionally, the MCU module includes an MCU chip, an external input port, a voltage acquisition port, a current acquisition port, a working control port, and a braking control port. The MCU chip is respectively connected to the external input port, the voltage acquisition port, the current acquisition port, the working control port, and the braking control port. The motor circuit is respectively connected to the voltage acquisition port and the current acquisition port. The external input port is connected to an external switch and the given module. The voltage acquisition port is used to acquire the working voltage of the motor circuit and send the working voltage to the MCU chip as a power generation signal. The current acquisition port is used to acquire the working current of the motor circuit and send the working current to the MCU chip. The external input port is used to acquire the input switch information and the given signal. The MCU chip is used to determine the comparison information corresponding to the power generation signal and the given signal, and generate a control signal according to the comparison information and the switch information. The working control port is connected to the driving circuit, and the working control port is used to send the motor working signal in the control signal. The braking control port is connected to the braking circuit, and the braking control port is used to send the motor stop signal in the control signal.

[0027] Optionally, the driving circuit includes a first resistor, an NPN transistor, a second resistor, a third resistor, a supply voltage, and a PMOS transistor. The first end of the first resistor is connected to the working control port, the second end of the first resistor is connected to the base of the NPN transistor, the emitter of the NPN transistor is connected to the system power ground, the collector of the NPN transistor is sequentially connected to the first end of the third resistor and the first end of the second resistor, the second end of the second resistor is sequentially connected to the supply voltage and the source of the PMOS transistor, the second end of the third resistor is connected to the gate of the PMOS transistor, and the drain of the PMOS transistor is sequentially connected to the motor circuit and the braking circuit;

[0028] The braking circuit includes a fourth resistor and an NMOS transistor. The first end of the fourth resistor is connected to the braking control port, the second end of the fourth resistor is connected to the gate of the NMOS transistor, the source of the NMOS transistor is connected to the motor circuit, and the drain of the NMOS transistor is connected to the drain of the PMOS transistor;

[0029] The motor circuit includes a fifth resistor, a wire feeding motor, and a diode. The first end of the fifth resistor is sequentially connected to the source of the NMOS transistor and the system power ground. The second end of the fifth resistor is sequentially connected to the current acquisition port, the positive electrode of the diode, and the first end of the wire feeding motor. The second end of the wire feeding motor is sequentially connected to the negative electrode of the diode, the voltage acquisition port, and the drain of the PMOS transistor.

[0030] In addition, to achieve the above object, the present invention further provides a wire feeding motor control device for a welding machine, including: a memory, the above-mentioned wire feeding motor control circuit for a welding machine, a processor, and a wire feeding motor control program for a welding machine stored on the memory and executable on the processor. When the wire feeding motor control program for a welding machine is executed by the processor, the steps of the above-mentioned wire feeding motor control method for a welding machine are implemented.

[0031] In addition, to achieve the above object, the present invention further provides a computer storage medium for controlling a wire feeding motor of a welding machine. A program for controlling a wire feeding motor of a welding machine is stored on the computer storage medium. When the program for controlling a wire feeding motor of a welding machine is executed by a processor, the steps of the above-mentioned wire feeding motor control method are implemented.

[0032] The present invention provides a control method for a wire feeding motor of a welding machine and a control circuit for the wire feeding motor of the welding machine. The method includes obtaining switch information, determining a speed given signal based on the switch information, and controlling the wire feeding motor of the welding machine to operate according to the speed given signal; collecting the power generation signal of the wire feeding motor of the welding machine based on a preset intermittent time, and obtaining comparison information by comparing the power generation signal with the speed given signal; generating a control signal according to the comparison information, and controlling the wire feeding motor of the welding machine to operate at a stable speed according to the control signal. Corresponding to the description of the control circuit for the wire feeding motor of the welding machine, the MCU module collects the power generation signal of the motor circuit (here referring to the power generation voltage generated by the inertial rotation when the power supply of the motor circuit actually stops), and then determines the comparison information of the given voltage of the given signal according to the power generation signal. Finally, the MCU module generates a control signal through the comparison information and the input switch information, and sends it to the drive circuit and the brake circuit. The drive circuit and the brake circuit control the motor in the motor circuit according to the control signal. Thereby, the phenomenon of adding devices such as an optical code disk, a power generation coil, and a magnet to the rotating shaft of the motor in the existing solution is avoided. This control circuit for the wire feeding motor of the welding machine can not only generate a control signal in the MCU module according to the comparison information and the input switch information to control the motor circuit, thereby ensuring the accuracy of control, but also directly realize motor control through the MCU module, the drive circuit, and the brake circuit, thereby reducing the control cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0034] Figure 1 It is a schematic flowchart of the first embodiment of the control method for the wire feeding motor of the welding machine of the present invention;

[0035] Figure 2 It is a schematic framework structure diagram of an embodiment of the control circuit for the wire feeding motor of the welding machine of the present invention;

[0036] Figure 3 It is a schematic diagram of the control principle of the existing wire feeding motor of the welding machine;

[0037] Figure 4 It is a system block diagram of the control circuit for the wire feeding motor of the welding machine of the present invention;

[0038] Figure 5 It is an internal schematic diagram of the MCU module in the control circuit for the wire feeding motor of the welding machine of the present invention;

[0039] Figure 6 It is the circuit connection diagram of the wire feeding motor control circuit of the electric welding machine of the present invention;

[0040] Figure 7 It is the schematic diagram of the technical solution of the wire feeding motor control method of the electric welding machine of the present invention;

[0041] Figure 8 It is the schematic diagram of the structure of the wire feeding motor control device of the hardware operating environment involved in the embodiment solution of the present invention;

[0042] Figure 9 It is the PWM waveform diagram of the wire feeding motor control method of the electric welding machine of the present invention.

[0043] Explanation of the reference numerals in the drawings:

[0044] Label Name Label Name 10 MCU Module 20 Driver Circuit 30 Brake Circuit 40 Motor Circuit 11 MCU Chip 12 External Input Port 13 Voltage Acquisition Port 14 Current Acquisition Port 15 Working Control Port 16 Brake Control Port 00 External Switch R1 First Resistor R2 Second Resistor R3 Third Resistor R4 Fourth Resistor R5 Fifth Resistor Q1 NPN Transistor Q2 PMOS Transistor Q3 NMOS Transistor VCC Power Supply Voltage M1 Wire Feeding Motor D1 Diode 50 Given Module

[0045] The realization, functional characteristics and advantages of the object of the present invention will be further described in conjunction with the embodiments with reference to the drawings. Specific embodiments

[0046] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0047] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a certain specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0048] In addition, if there are descriptions such as "first", "second", etc. involved in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0049] The present invention proposes a wire feeding motor control method for an electric welding machine.

[0050] In an embodiment of the present invention, as Figure 1 shown, Figure 1 FIG. 1 is a schematic flowchart of a first embodiment of a method for controlling a wire feeding motor of a welding machine. The method for controlling the wire feeding motor of the welding machine includes:

[0051] Step S10: Obtain switch information, determine a speed given signal based on the switch information, and control the wire feeding motor of the welding machine to operate according to the speed given signal;

[0052] In this embodiment, when it is determined that the MCU module obtains the input switch information, mainly obtained based on the connection between the external input port 12 and the external switch 00, the speed given signal given by the given module to the MCU module will be determined according to the switch information. Among them, the switch information refers to the instruction to control the start of the wire feeding motor of the welding machine, and the speed given signal refers to the signal for giving the rotation speed of the wire feeding motor of the welding machine. Then, the wire feeding motor of the welding machine will be controlled to rotate normally based on this speed given signal. Illustrated with a circuit example diagram, the MCU chip in the MCU module can judge the switch information. When the switch information is a shutdown instruction, a stop level will be generated based on the shutdown instruction, and the stop level will be sent to the brake circuit through the brake control port in the MCU module, and the wire feeding motor in the motor circuit will be controlled to stop working through the brake circuit. Among them, the shutdown instruction refers to the instruction generated when the state of the external switch being closed is received, and the stop level refers to the level for controlling the wire feeding motor corresponding to the shutdown instruction. Here, it can be customized according to the user, and can be defined as high-level shutdown or low-level shutdown. The stop level will be sent to the brake circuit to make the brake circuit work and then shut down the wire feeding motor. On the other hand, the output voltage of the drive circuit will be stopped, so that the wire feeding motor does not work. Conversely, when the switch information is an opening instruction, the step of determining the speed given signal based on the switch information will be executed, and the wire feeding motor of the welding machine will be started through a specific level.

[0053] Step S20: Collect the generated power signal of the wire feeding motor of the welding machine based on a preset intermittent time, and compare the generated power signal with the speed given signal to obtain comparison information;

[0054] In this embodiment, the step of collecting the generated power signal of the wire feeding motor of the welding machine based on a preset intermittent time includes:

[0055] Step C11: Obtain working duration information, and detect whether the working time in the working duration information matches the preset intermittent time;

[0056] In this embodiment, by obtaining the working duration information of the wire feeding motor of the electric welding machine in real time and detecting whether the working time in the working duration information matches the preset intermittent time, that is to say, in this embodiment, the detection speed is actually carried out every period of time. The working duration information refers to the working time information of the wire feeding motor of the electric welding machine. For example, if the working duration information is 5 min, the working time in the working duration information is 5 min. The preset intermittent time also refers to a length of time, mainly to detect whether it matches the preset intermittent time and then collect the discharge information.

[0057] Step C12: If the working time in the working duration information matches the preset intermittent time, trigger a power supply stop command and stop supplying power to the wire feeding motor of the electric welding machine based on the power supply stop command;

[0058] Step C13: Collect the working voltage of the wire feeding motor of the electric welding machine that has stopped power supply as a power generation signal.

[0059] In this embodiment, when the working time in the working duration information does not match the preset interruption time, the step of obtaining the working duration information is continuously executed, and it is detected whether the working time in the working duration information matches the preset interruption time until the working time in the working duration information matches the preset interruption time, a power supply stop instruction is triggered, and based on the power supply stop instruction, the power supply to the wire feeding motor of the electric welding machine is stopped. Finally, the working voltage is collected based on the wire feeding motor of the electric welding machine that has stopped power supply as a power generation signal. Among them, the power supply stop instruction refers to the instruction to stop the power supply to the wire feeding motor of the electric welding machine, causing the wire feeding motor of the electric welding machine to rotate inertially, and collecting the working voltage of its power generation according to the inertially rotating wire feeding motor of the electric welding machine as a power generation signal, that is, stopping the power supply and collecting the working voltage of inertial rotation for speed detection after each preset interruption time. In combination with the subsequent circuit for combined explanation, the MCU chip in the MCU module will obtain the power generation signal of the motor circuit in each preset delay period. The preset delay period refers to a time period, and the obtaining operation is performed after a time period. The obtaining operation also includes stopping the PWM power supply at the end of the cycle time to make the wire feeding motor rotate inertially. For example, stopping the PWM power supply every 30 minutes and collecting the working voltage at this time as a power generation signal, the comparison information corresponding to the power generation signal will be determined inside the MCU chip. The power generation signal refers to the working voltage when the motor rotates inertially, and the comparison information refers to the comparison result or difference between the working voltage and the theoretical voltage. Before obtaining the collected power generation signal based on the preset delay period, the MCU chip will also collect the working current of the motor circuit in real time and detect whether the working current is greater than the maximum working current. When it is greater than the maximum working current, an alarm instruction will be generated, and the corresponding alarm component will be controlled to alarm according to the alarm instruction. Here, the alarm instruction can be the operation of the indicator light, the display on the display screen, or the forced power-off instruction, etc. Among them, the step of obtaining comparison information by comparing the power generation signal and the speed given signal includes:

[0060] Step C14, determining the working voltage in the power generation signal and detecting whether the working voltage matches the given voltage of the speed given signal;

[0061] Step C16, if the working voltage does not match the given voltage of the speed given signal, determining the voltage difference between the given voltage and the working voltage as the comparison information.

[0062] In this embodiment, by determining the working voltage in the power generation signal and simultaneously detecting whether the working voltage matches the given voltage of the speed given signal, it is actually to compare the voltage difference between the working voltage and the given voltage. The voltage difference can be customized such that when the difference is greater than M, the comparison information becomes effective, and when it is less than M, the comparison information is ineffective. When the two match, the pulse width of the PWM used before the next power supply will be used; when they do not match, the voltage difference between the given voltage of the speed given signal and the working voltage will be calculated by the MCU chip in the MCU module to determine the comparison information. Among them, the given voltage of the speed given signal refers to the actually input working voltage, the voltage given by the given module, and is also the theoretical voltage mentioned above.

[0063] Step S30, generate a control signal according to the comparison information, and control the wire feeding motor of the welding machine to operate at a stable speed according to the control signal.

[0064] In this embodiment, the internal control module will generate a control signal based on the comparison information. Among them, the step of generating a control signal according to the comparison information includes:

[0065] Step C21, determine the voltage difference in the comparison information, and look up the table according to the voltage difference to determine the PWM wave pulse width control instruction corresponding to the difference in the comparison information;

[0066] Step C22, use the PWM wave pulse width control instruction as the control signal.

[0067] In this embodiment, by determining the initial PWM pulse width corresponding to the start instruction, the wire feeding motor is rotationally controlled based on the initial PWM pulse width (the initial voltage is also the initial theoretical voltage). Until the comparison information is received, the PWM wave pulse width control instruction corresponding to the voltage difference in the comparison information will be looked up in the MCU module. Finally, the PWM wave pulse width control instruction will be used as the control signal. Among them, the PWM wave pulse width control instruction refers to the instruction for controlling the output PWM wave pulse width. For example, when the difference in the comparison information is H, the required PWM wave pulse width corresponding to the difference of H is H1, and the control instruction H11 corresponding to the PWM wave pulse width H1 will be found. Then H11 is the instruction for the required PWM wave pulse width, and thus the waveform with the PWM wave pulse width of H1 can be controlled to be output, thereby realizing the control of the wire feeding motor. Among them, after the step of using the PWM wave pulse width control instruction as the control signal, it includes:

[0068] Step C21, determine the pulse width correction instruction in the PWM wave pulse width control instruction, and correct the pulse width of the preset output PWM wave according to the pulse width correction instruction;

[0069] Step C22: Control the wire feeding motor of the electric welding machine based on the corrected preset output PWM wave, and execute the step of obtaining the collected power generation signal based on the preset intermittent time.

[0070] In this embodiment, by determining the pulse width correction instruction in the PWM wave pulse width control instruction and correcting the pulse width of the preset output PWM wave through the pulse width correction instruction, the wire feeding motor of the electric welding machine can be controlled based on the corrected preset output PWM wave. Then, execute the step of obtaining the collected power generation signal based on the preset intermittent time to facilitate real-time speed detection. Among them, the pulse width correction instruction refers to the instruction for correcting the pulse width of the PWM wave, and the preset output PWM wave refers to the previously input PWM wave. The pulse width of the previously input PWM wave is corrected according to the pulse width correction instruction, thereby achieving speed control. At the same time, continue to execute step S10, and then the speed of the entire process can be monitored in real time. When the control signal is the PWM wave pulse width control instruction, the PWM wave pulse width control instruction will be input into the MCU chip in the MCU module to control the corresponding PWM wave output by the working control port, thereby realizing the control of the wire feeding motor speed. Or, when it is detected that no PWM wave pulse width control instruction is generated internally, the PWM wave will not be changed (indicating that the wire feeding motor speed is accurate), and the previous PWM wave will continue to be used to control the wire feeding motor. On the one hand, it can ensure the accuracy of controlling the wire feeding motor. On the other hand, compared with the existing solution that requires installing a detection instrument on the motor, the solution used in this application is simpler, has lower cost, and is easier to design.

[0071] Further, this embodiment also provides a schematic diagram of a control technical solution for the wire feeding motor of an electric welding machine. Refer to Figure 7 , Figure 7It is a schematic diagram of the technical solution of the wire feeding motor control method for a welding machine. When starting wire feeding, speed setting is carried out, and then the initial value of the PWM output is determined according to the set speed, and further the wire feeding motor is controlled to operate with the pulse width corresponding to the wire feeding initial value, that is, the motor in the wire feeding initial state operates with a fixed PWM initial pulse width (the initial operating state of the motor when powered on). After a delay time T0 (the optimal time obtained according to user settings or multiple experiments), the PWM output is set to 0, that is, power off and the motor runs by inertia (the inertia operating state of the motor when powered off). During the delay time T1 (the optimal time obtained according to user settings or multiple experiments, the shorter the time, the more accurate the sampling), the discharge of the motor, that is, the motor speed, is sampled. By comparing with the speed setting, the speed error is obtained, and the speed PID regulation operation is carried out to output the PWM value PID.OUT (speed sampling and PID operation). The PID operation refers to the process of determining the output PWM value PID.OUT based on the speed error, which can be specifically obtained by looking up a table according to the speed error. Finally, the motor is controlled to operate with a fixed PID.OUT pulse width (the operating state of the motor when powered on), and after the delay time T0, the steps of the inertia operating state of the motor when powered off are continued. Refer to Figure 9 , Figure 9 It is the PWM waveform diagram of the wire feeding motor control method for a welding machine. Specifically, the enlarged waveform diagram in the figure (the lower part of the figure) can be referred to. The three blank parts in the figure refer to the delay time T0 and the delay time T1. T0 refers to the position from a to the end of the waveform in the figure, and the delay time T1 refers to the position from the end of the waveform to b. The rising waveform between the end of the waveform and b is the motor voltage that needs to be sampled. The motor speed (speed voltage) is sampled through the delay time, and compared with the speed setting (theoretical voltage) to obtain PID.OUT. Finally, the motor is controlled by PID.OUT, and a cycle is carried out during the delay time T0, so as to ensure the accuracy of the wire feeding motor control and the control cost is relatively low compared with the existing solutions.

[0072] This embodiment provides a control method for a wire feeding motor of a welding machine and a control circuit for the wire feeding motor of the welding machine. The method includes obtaining a collected power generation signal based on a preset intermittent time, and determining comparison information according to the power generation signal and a preset given signal; obtaining input switch information, and generating a control signal according to the switch information and the comparison information; and controlling the wire feeding motor of the welding machine to work according to the control signal. Corresponding to the description of the control circuit of the wire feeding motor of the welding machine, the MCU module collects the power generation signal of the motor circuit (here, it refers to the power generation voltage generated by the inertial rotation when the power supply of the motor circuit actually stops), and then determines the comparison information of the given voltage of the given signal according to the power generation signal. Finally, the MCU module generates a control signal according to the comparison information and the input switch information, and sends it to the drive circuit and the brake circuit. The drive circuit and the brake circuit control the motor in the motor circuit according to the control signal. Thus, it avoids the phenomenon of adding devices such as optical code disks, power generation coils, and magnets to the rotating shaft of the motor in the existing solutions. This control circuit for the wire feeding motor of the welding machine can not only generate a control signal in the MCU module according to the comparison information and the input switch information to control the motor circuit, thereby ensuring the accuracy of the control, but also directly realize the motor control through the MCU module, the drive circuit, and the brake circuit, thereby reducing the control cost.

[0073] Further, referring to Figure 8 , Figure 8 is a schematic structural diagram of a control device for a wire feeding motor of a welding machine, which is the hardware operating environment involved in the solution of the embodiment of the present invention.

[0074] As Figure 8 shown, the control device for the wire feeding motor of the welding machine may include: a processor 0003, such as a central processing unit (CPU), a communication bus 0001, an acquisition interface 0002, a processing interface 0004, and a memory 0005. Among them, the communication bus 0001 is used to realize the connection and communication between these components. The acquisition interface 0002 may include an information acquisition device, an acquisition unit such as a computer. Optionally, the acquisition interface 0002 may further include a standard wired interface and a wireless interface. The processing interface 0004 may optionally include a standard wired interface and a wireless interface. The memory 0005 may be a high-speed random access memory (RAM), or a stable non-volatile memory (NVM), such as a disk memory. Optionally, the memory 0005 may also be a storage device independent of the foregoing processor 0003.

[0075] Those skilled in the art can understand, Figure 8The structure shown does not constitute a limitation on the wire feeding motor control device of the electric welding machine, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0076] As Figure 8 shown, in the memory 0005 as a computer storage medium, an operating system, an acquisition interface module, a processing interface module, and a wire feeding motor control program for the electric welding machine may be included.

[0077] In Figure 8 the wire feeding motor control device of the electric welding machine shown, the communication bus 0001 is mainly used to realize the connection and communication between components; the acquisition interface 0002 is mainly used to connect to the background server and conduct data communication with the background server; the processing interface 0004 is mainly used to connect to the deployment end (user end) and conduct data communication with the deployment end; the processor 0003 and the memory 0005 in the wire feeding motor control device of the present invention may be arranged in the wire feeding motor control device of the electric welding machine. The wire feeding motor control device of the electric welding machine calls the wire feeding motor control program stored in the memory 0005 through the processor 0003 and executes the wire feeding motor control method provided by the embodiments of the present invention.

[0078] Further, referring to as Figure 2 shown, based on an embodiment of the above wire feeding motor control method, a schematic framework structure diagram of an embodiment of the wire feeding motor control circuit of the present invention is proposed. The steps of the wire feeding motor control circuit include a given module 50, an MCU module 10, a drive circuit 20, a brake circuit 30, and a motor circuit 40;

[0079] The MCU module 10 is respectively connected to the given module 50, the drive circuit 20, the brake circuit 30, and the motor circuit 40. The MCU module 10 is used to collect the power generation signal of the motor circuit 40, determine the comparison information corresponding to the power generation signal and the given signal of the given module, and generate a control signal according to the input switch information and the comparison information;

[0080] The drive circuit 20 is respectively connected to the brake circuit 30 and the motor circuit 40. The drive circuit 20 is used to control the operation of the motor circuit 40 according to the control signal;

[0081] The brake circuit 30 is connected to the motor circuit 40. The brake circuit 30 is used to control the motor circuit 40 to brake and stop operating according to the control signal.

[0082] The commonly used gas metal arc welding machine uses a welding wire as the consumable electrode and filler metal. Through the continuous wire feeding of the wire feeding motor, heat is generated by the arc between the welding wire and the workpiece to melt the welding wire for continuous welding. The gas metal arc welding machine requires the output current, voltage of the welding power supply and the wire feeding speed to be strictly matched to form a stable arc for welding. Otherwise, wire jamming or arc breakage will occur and normal welding cannot be carried out. Refer to Figure 3 , Figure 3 is the control schematic diagram of the wire feeding motor of the existing electric welding machine. The positive and negative poles of the welding power supply module are respectively connected to the welding torch and the workpiece to be welded. The control module is also connected to the switch on the welding torch through the positive terminal. The welding power supply module also outputs voltage to the control module. The voltage is processed by the control module and outputs a specific voltage to the motor (wire feeding motor). The rotation of the motor is connected to the welding wire to control the accurate wire feeding of the wire spool to the welding torch. The wire feeding motor generally uses a DC motor and adjusts the speed by adjusting the pulse width of PWM. However, since the welding wire in the wire spool continuously decreases during use or the welding torch bends (the linear pulling force and the curved pulling force are different), the wire feeding resistance will be different. Especially when feeding wire at low current and low speed, the influence of the wire feeding resistance on the motor speed will cause unstable welding. In order to stabilize the wire feeding speed, usually an optical code disk or a generator coil, a magnet and other devices are added to the rotating shaft of the motor to feedback the motor speed, and the driver is adjusted in time through the feedback signal to stabilize the motor speed. However, this device is relatively complex and the cost is high, which brings limitations to the popularization and use of small-scale civilian gas shielded welding machines.

[0083] Based on the above defects, the technical solution of this application is proposed, which uses a common DC motor to obtain the feedback signal of the motor speed by reserving the detection time while driving the motor without adding a speed feedback device to control the speed of the wire feeding motor. Refer to Figure 4 , Figure 4 is the system block diagram of the control circuit of the wire feeding motor of the electric welding machine. By reserving an intermittent time in the driving signal of the motor, the generated power signal during the inertial rotation of the motor is detected during the reserved intermittent time to control the motor speed and keep the wire feeding speed relatively stable. The main control process is as follows: The manual switch signal (the switch on the welding torch) and the given signal (wire feeding speed) can be given by the given module 50, and then the control module provides a PWM driving signal to the wire feeding motor to drive the wire feeding motor inside the wire feeder. When in the driving signal intermittent period, the actual speed of the motor is detected through the motor generated power signal and then fed back to the control module, and the control module re-gives a new PWM driving signal to the wire feeding motor according to the detected generated power signal fed back. That is, the detection and re-giving of a new PWM driving signal are carried out during each driving signal intermittent period (if the speed requirement is met, the previous PWM driving signal is continued), so as to realize the stable output of the wire feeding speed, and the use cost is also lower compared with the existing scheme.

[0084] In this embodiment, when the motor circuit 40 operates, the generated power signal of the motor circuit 40 is collected at a specific time (the delay time T0 mentioned above), and comparison information is determined in the MCU module 10 according to the generated power signal. Finally, a control signal is generated based on the comparison information and the input switch information. The function of the setting module 50 is to set a wire feeding speed for the MCU module 10, and the MCU module 10 controls the wire feeding speed. The setting module can be an input instrument or the like. Among them, the generated power signal refers to the working current and working voltage of the motor circuit 40 (here refers to the motor voltage after actual power-off and the working current during actual operation), the comparison information refers to the comparison result of the working current and working voltage with the theoretical current and theoretical voltage, mainly to determine whether it meets the theoretical requirements, the control signal refers to the result of determining whether the voltage and current meet the requirements and the control instruction for determining whether to turn on or off the machine, and the switch information refers to the information of whether the switch is pressed or not, and the corresponding speed setting (theoretical voltage) is selected when the switch is pressed. Finally, the control signal is sent to the drive circuit 20 or the brake circuit 30 to control the motor circuit 40 to stop or start at different speeds. For example, when the switch information is that the switch is not pressed, a control signal is generated to directly control the brake circuit 30 to stop the wire feeding motor in the motor circuit 40 from rotating; when the switch information is that the switch is pressed, the corresponding theoretical voltage is determined and output to the drive circuit 20 to control the wire feeding motor in the motor circuit 40 to rotate. On the one hand, the working current is collected in real time or at a specific time. When the working current is greater than the preset maximum working current (set by the user or obtained through experiments), the corresponding alarm device or indicator light is controlled to give an alarm; on the other hand, the working voltage in the generated power signal is collected after a specific time, and the working voltage is compared with the theoretical voltage to obtain comparison information. When the comparison information is that the voltage difference between the two is within the range, the wire feeding motor is driven with the previous theoretical voltage. Conversely, when the comparison information is that the voltage difference between the two is not within the range, the new theoretical voltage corresponding to the difference is determined, and the wire feeding motor is driven according to the new theoretical voltage. By detecting the actual voltage of the motor, the motor speed can be accurately controlled, and the cost is also saved compared with the existing speed control.

[0085] In one embodiment, as shown in Figure 5 the figure Figure 5It is the internal schematic diagram of the MCU module in the wire feeding motor control circuit of the electric welding machine. The MCU module 10 includes an MCU chip 11, an external input port 12, a voltage acquisition port 13, a current acquisition port 14, a working control port 15, and a brake control port 16. The MCU chip 11 is respectively connected to the external input port 12, the voltage acquisition port 13, the current acquisition port 14, the working control port 15, and the brake control port 16. The motor circuit 40 is respectively connected to the voltage acquisition port 13 and the current acquisition port 14. The external input port 12 is connected to the external switch 00. The voltage acquisition port 13 is used to acquire the working voltage of the motor circuit 40 and send the working voltage to the MCU chip 11 as a power generation signal. The current acquisition port 14 is used to acquire the working current of the motor circuit 40 and send the working current to the MCU chip 11 as a power generation signal. The external input port 12 is used to acquire the input switch information. The MCU chip 11 is used to determine the comparison information corresponding to the power generation signal and generate a control signal according to the comparison information and the switch information. The working control port 15 is connected to the drive circuit 20, and the working control port 15 is used to send the motor working signal in the control signal. The brake control port 16 is connected to the brake circuit 30, and the brake control port 16 is used to send the motor stop signal in the control signal.

[0086] In this embodiment, the external input port 12 inputs the externally input switch information into the MCU chip 11. The MCU chip 11 can be a single-chip microcomputer into which the control program for the wire feeding motor of the welding machine has been burned. The external input port 12, the voltage acquisition port 13, and the current acquisition port 14 can be the external data interfaces of the single-chip microcomputer. The working control port 15 and the brake control port 16 can be the IO ports of the single-chip microcomputer. On the other hand, after the delay time, the working voltage and working current of the motor circuit 40 are collected through the voltage acquisition port 13 and the current acquisition port 14 and sent to the MCU chip 11. On the one hand, the MCU chip 11 determines whether an alarm instruction needs to be generated according to whether the working current meets the requirements. The alarm instruction is a related instruction for alarming the operation of the motor. On the other hand, when the externally input switch information received is the motor start instruction (i.e., the start switch is turned on), a corresponding control signal is generated according to the difference between the working voltage and the theoretical voltage (the difference does not meet the requirements), so as to control the drive circuit 20 through the motor working signal in the control signal to realize different control pulse widths for the motor circuit 40. Among them, the motor working signal refers to outputting a specific PWM pulse width waveform. Conversely, when the difference meets the requirements, the original PWM pulse width is used for control. When the externally input switch information received is the motor stop instruction (i.e., the start switch is turned off), the brake control port 16 is controlled to output a shutdown level (if it can be shut down by a low level, a low level is output; if it can be shut down by a high level, a high level is output), and the working control port 15 stops outputting, finally directly shutting down the motor in the motor circuit 40, thereby ensuring the accuracy of the start and stop control of the wire feeding motor.

[0087] In one embodiment, as shown in Figure 6 the figure Figure 6 is the circuit connection diagram of the control circuit for the wire feeding motor of the welding machine. The drive circuit 20 includes a first resistor R1, an NPN transistor Q1, a second resistor R2, a third resistor R3, a supply voltage VCC, and a PMOS transistor Q2. The first end of the first resistor R1 is connected to the working control port 15, the second end of the first resistor R1 is connected to the base B of the NPN transistor Q1, the emitter E of the NPN transistor Q1 is connected to the system power ground, the collector C of the NPN transistor Q1 is sequentially connected to the first end of the third resistor R3 and the first end of the second resistor R2, the second end of the second resistor R2 is sequentially connected to the supply voltage VCC and the source S of the PMOS transistor Q2, the second end of the third resistor R3 is connected to the gate G of the PMOS transistor Q2, and the drain D of the PMOS transistor Q2 is sequentially connected to the motor circuit 40 and the brake circuit 30.

[0088] Specifically, the braking circuit 30 includes a fourth resistor R4 and an NMOS transistor Q3. The first end of the fourth resistor R4 is connected to the braking control port 16, the second end of the fourth resistor R4 is connected to the gate G of the NMOS transistor Q3, the source S of the NMOS transistor Q3 is connected to the motor circuit 40, and the drain D of the NMOS transistor Q3 is connected to the drain D of the PMOS transistor Q2.

[0089] Specifically, the motor circuit 40 includes a fifth resistor R5, a wire feeding motor M1, and a diode D1. The first end of the fifth resistor R5 is sequentially connected to the source S of the NMOS transistor Q3 and the system power ground. The second end of the fifth resistor R5 is sequentially connected to the current acquisition port 14, the positive electrode of the diode D1, and the first end of the wire feeding motor M1. The second end of the wire feeding motor M1 is sequentially connected to the negative electrode of the diode D1, the voltage acquisition port 13, and the drain D of the PMOS transistor Q2. In this embodiment, after the MCU chip 11 of the MCU module 10 receives the wire feeding speed given signal and the hand switch signal, it starts to issue a PWM motor drive signal. The wire feeding speed given signal and the hand switch signal (starting to work when the switch is closed) are input through the external input port 12. When the PWM motor drive signal is at a high level (output by the working control port 15), the NPN transistor Q1 conducts, and the PMOS transistor Q2 conducts simultaneously, driving the wire feeding motor M1 to start rotating. Refer to Figure 5 , the high level makes the NPN transistor Q1 and the PMOS transistor Q2 conduct simultaneously, and the NMOS transistor Q3 is turned off (no level is output by the braking control port 16). When the MCU sends the motor drive signal, a short interruption time (delay time T0) will be reserved in the middle, and the power generation signal of the motor rotating due to inertia will be detected during the interruption period. The voltage is collected through the voltage acquisition port 13 as the power generation signal. After comparing the power generation signal of the motor and the given signal of the motor in the MCU, it is judged whether the rotation speed of the motor is consistent with the rotation speed required by the given signal, and the PWM pulse width is adjusted by the MCU chip for correction. And the comparison and correction operation will be continued at the next delay time T0, thereby ensuring the accuracy of the entire wire feeding motor control process. When the hand switch signal is disconnected (the switch is disconnected to stop working), the MCU receives the welding stop signal, the working control port 15 stops sending waves, and a braking signal (low level) is sent through the braking control port 16. The NMOS transistor Q3 conducts, making the motor stop rotating quickly. D1 is to prevent the reverse voltage from being too high and damaging the braking tube during braking. The fifth resistor R5 is a current sampling resistor for the motor. When the current of the fifth resistor R5 exceeds the preset range, it is judged that the wire feeding resistance of the motor is too large or the motor is blocked due to external reasons. The working current is fed back to the MCU through the current acquisition port 14, and the MCU controls the motor to stop working and issues an alarm signal. Thereby, the safety of the wire feeding motor can be ensured.

[0090] The present invention also provides a control device for the wire feeding motor of a welding machine.

[0091] The device of the present invention includes: a memory, the above-mentioned control circuit for the wire feeding motor of the welding machine, a processor, and a control program for the wire feeding motor of the welding machine stored on the memory and executable on the processor. When the control program for the wire feeding motor of the welding machine is executed by the processor, the steps of the control method for the wire feeding motor of the welding machine as described above are implemented.

[0092] The present invention also provides a computer storage medium.

[0093] A control program for the wire feeding motor of the welding machine is stored on the computer storage medium of the present invention. When the control program for the wire feeding motor of the welding machine is executed by the processor, the steps of the control method for the wire feeding motor of the welding machine as described above are implemented.

[0094] Among them, the method implemented when the control program for the wire feeding motor of the welding machine running on the processor is executed can refer to each embodiment of the control method for the wire feeding motor of the welding machine of the present invention, which will not be elaborated here.

[0095] The above are only optional embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made by using the description and drawings of the present invention under the inventive concept of the present invention, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A control method for the wire feeding motor of a welding machine, characterized in that, The control method of the wire feeding motor of the electric welding machine adopts the control circuit of the wire feeding motor of the electric welding machine. The control circuit of the wire feeding motor of the electric welding machine includes an MCU module, a braking circuit and a motor circuit. The control method of the wire feeding motor of the electric welding machine includes the following steps: Obtain switch information, and determine a speed given signal based on the switch information. Control the wire feeding motor of the electric welding machine to work according to the speed given signal. Among them, when the switch information is a shutdown instruction, a stop level is generated based on the shutdown instruction, and the stop level is sent to the braking circuit through the braking control port in the MCU module to control the wire feeding motor in the motor circuit to stop working through the braking circuit; Collect the power generation signal of the wire feeding motor of the electric welding machine based on a preset intermittent time, and compare the power generation signal with the speed given signal to obtain comparison information. Among them, the step of collecting the power generation signal of the wire feeding motor of the electric welding machine based on a preset intermittent time includes: Obtain working duration information, and detect whether the working time in the working duration information matches the preset intermittent time; if the working time in the working duration information matches the preset intermittent time, trigger a power supply stop instruction, and stop supplying power to the wire feeding motor of the electric welding machine based on the power supply stop instruction; collect the working voltage of the wire feeding motor with power supply stopped as the power generation signal; Generate a control signal according to the comparison information, and control the wire feeding motor of the electric welding machine to work at a stable speed according to the control signal. Among them, the control signal includes a preset output PWM wave after correction.

2. The welding machine wire feeding motor control method according to claim 1, wherein The step of comparing the power generation signal with the speed given signal to obtain comparison information includes: Determine the working voltage in the power generation signal, and detect whether the working voltage matches the given voltage of the speed given signal; If the working voltage does not match the given voltage of the speed given signal, determine the voltage difference between the given voltage and the working voltage as the comparison information.

3. The welding machine wire feeding motor control method according to claim 1, characterized in that The step of generating a control signal according to the comparison information includes: Determine the voltage difference in the comparison information, and look up a table according to the voltage difference to determine the PWM wave pulse width control instruction corresponding to the difference in the comparison information; Use the PWM wave pulse width control instruction as the control signal.

4. The control method of the wire feeding motor of the electric welding machine according to claim 3, wherein, After the step of using the PWM wave pulse width control instruction as the control signal, it includes: Determine the pulse width correction instruction in the PWM wave pulse width control instruction, and correct the pulse width of the preset output PWM wave according to the pulse width correction instruction; Control the wire feeding motor of the electric welding machine based on the preset output PWM wave after correction, and execute the step of obtaining the collected power generation signal based on the preset intermittent time.

5. A wire feeding motor control circuit for an electric welding machine, characterized in that, The control circuit of the wire feeding motor of the electric welding machine is applied to the control method of the wire feeding motor of the electric welding machine according to any one of claims 1 to 4. The control circuit of the wire feeding motor of the electric welding machine includes a given module, an MCU module, a driving circuit, a braking circuit and a motor circuit; The MCU module is respectively connected to the given module, the drive circuit, the brake circuit, and the motor circuit. The MCU module is used to collect the power generation signal of the motor circuit, determine the comparison information corresponding to the power generation signal and the given signal of the given module, and generate a control signal according to the input switch information and the comparison information. Among them, the step of the MCU module for collecting the power generation signal of the motor circuit includes: obtaining the working duration information and detecting whether the working time in the working duration information matches the preset intermittent time; if the working time in the working duration information matches the preset intermittent time, triggering a power supply stop instruction and stopping the power supply to the wire feeding motor of the electric welding machine based on the power supply stop instruction; collecting the working voltage as the power generation signal based on the wire feeding motor of the electric welding machine with the power supply stopped. The control signal includes the preset output PWM wave after correction. The MCU module is further used to, when the switch information is a shutdown instruction, generate a stop level based on the shutdown instruction and send the stop level to the brake circuit to control the wire feeding motor in the motor circuit to stop working through the brake circuit; The drive circuit is respectively connected to the brake circuit and the motor circuit. The drive circuit is used to control the wire feeding motor of the electric welding machine to work according to the control signal; The brake circuit is connected to the motor circuit. The brake circuit is used to control the motor circuit to brake and stop working according to the control signal. Among them, the brake circuit includes a fourth resistor and an NMOS transistor. The first end of the fourth resistor is connected to the brake control port in the MCU module, the second end of the fourth resistor is connected to the gate of the NMOS transistor, the source of the NMOS transistor is connected to the motor circuit, and the drain of the NMOS transistor is connected to the drain of the PMOS transistor in the drive circuit.

6. The wire-feeding motor control circuit of the electric welding machine according to claim 5, wherein, The MCU module includes an MCU chip, an external input port, a voltage acquisition port, a current acquisition port, a working control port, and a braking control port. The MCU chip is respectively connected to the external input port, the voltage acquisition port, the current acquisition port, the working control port, and the braking control port. The motor circuit is respectively connected to the voltage acquisition port and the current acquisition port. The external input port is connected to an external switch and the given module. The voltage acquisition port is used to acquire the working voltage of the motor circuit and send the working voltage to the MCU chip as a power generation signal. The current acquisition port is used to acquire the working current of the motor circuit and send the working current to the MCU chip. The external input port is used to acquire the input switch information and the given signal. The MCU chip is used to determine the comparison information corresponding to the power generation signal and the given signal, and generate a control signal according to the comparison information and the switch information. The working control port is connected to the drive circuit, and the working control port is used to send the motor working signal in the control signal. The braking control port is connected to the braking circuit, and the braking control port is used to send the motor stop signal in the control signal.

7. The wire feeding motor control circuit of the electric welding machine according to claim 6, characterized in that, The drive circuit includes a first resistor, an NPN transistor, a second resistor, a third resistor, a supply voltage, and a PMOS transistor. The first end of the first resistor is connected to the working control port, the second end of the first resistor is connected to the base of the NPN transistor, the emitter of the NPN transistor is connected to the system power ground, the collector of the NPN transistor is sequentially connected to the first end of the third resistor and the first end of the second resistor, the second end of the second resistor is sequentially connected to the supply voltage and the source of the PMOS transistor, the second end of the third resistor is connected to the gate of the PMOS transistor, and the drain of the PMOS transistor is sequentially connected to the motor circuit and the braking circuit; The motor circuit includes a fifth resistor, a wire feeding motor, and a diode. The first end of the fifth resistor is sequentially connected to the source of the NMOS transistor and the system power ground, the second end of the fifth resistor is sequentially connected to the current acquisition port, the positive electrode of the diode, and the first end of the wire feeding motor. The second end of the wire feeding motor is sequentially connected to the negative electrode of the diode, the voltage acquisition port, and the drain of the PMOS transistor.

8. A wire feeding motor control device for an electric welding machine, characterized in that, The wire feeding motor control device for the electric welding machine includes: a memory, a processor, the wire feeding motor control circuit for the electric welding machine according to any one of claims 5 to 7, and a wire feeding motor control program for the electric welding machine stored on the memory and executable on the processor. When the wire feeding motor control program for the electric welding machine is executed by the processor, the steps of the wire feeding motor control method for the electric welding machine according to any one of claims 1 to 4 are implemented.

9. A computer storage medium, characterized in that, The computer storage medium stores a wire feeding motor control program for a welding machine. When the wire feeding motor control program for the welding machine is executed by a processor, the steps of the wire feeding motor control method for the welding machine according to any one of claims 1 to 4 are implemented.

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