Brazing machine control system

Abstract

The invention discloses a brazing machine control system, the brazing machine control system is externally connected with an input power supply, the brazing machine control system comprises a main control unit, the main control unit comprises an isolation module, a control module, a heating module and a phase sequence detection module, the isolation module is used for isolating the control module from the input power supply; the power supply end of the heating module is connected with the output end of the isolation module so as to obtain direct-current power supply voltage; the first end of the heating module is connected with the A-phase power of the input power supply, the second end of the heating module is connected with the C-phase power of the input power supply through a transformer, and the heating module is used for controlling the heating power of the brazing machine based on the control module; the phase sequence detection module is used for detecting the phase sequence of the input power supply. The problems that a traditional brazing machine control system is inaccurate in heating control and lacks a phase sequence detection mechanism can be effectively solved, and the safety and the working efficiency of the brazing machine can be improved.

Description

Technical Field

[0001] The present application belongs to the field of brazing technology, and specifically relates to a brazing machine control system. Background Art

[0002] The existing brazing machine control system is not precise enough in controlling the heating power of the brazing machine, which affects the welding quality and production efficiency. In addition, the existing brazing machine control system lacks a phase sequence detection mechanism and cannot promptly detect and correct input power phase sequence errors, which can easily lead to equipment damage or unstable operation. Summary of the invention

[0003] The main purpose of the present application is to provide a brazing machine control system, aiming to solve the problems of inaccurate heating control and lack of phase sequence detection mechanism in the existing brazing machine control system.

[0004] To achieve the above objectives, this application provides the following technical solutions:

[0005] A brazing machine control system, the brazing machine control system is externally connected to an input power supply, the brazing machine control system comprises: a main control unit, the main control unit comprises an isolation module, a control module, a heating module and a phase sequence detection module, wherein the isolation module is used to isolate the control module from the input power supply; the power supply end of the heating module is connected to the output end of the isolation module to obtain a DC power supply voltage; the first end of the heating module is connected to the A phase electricity of the input power supply, and the second end is connected to the C phase electricity of the input power supply through a transformer, the heating module is used to control the heating power of the brazing machine based on the control module; the phase sequence detection module is used to detect the phase sequence of the input power supply.

[0006] Optionally, the isolation module includes: an isolation transformer and an AC / DC converter, wherein the primary side of the isolation transformer is connected to a power switch, and the secondary side of the isolation transformer is connected to the control module via the AC / DC converter, and the AC / DC converter is used to convert the alternating current provided by the input power supply into direct current that can be used by the control module.

[0007] Optionally, the control module includes: a PLC controller, the PLC controller is connected to the first output end of the AC / DC converter via a voltage pin, and the PLC controller is connected to the second output end of the AC / DC converter via a reference voltage pin.

[0008] Optionally, the control module also includes: a first relay, a second relay, a third relay and a fourth relay, wherein one end of the coil of the third relay is connected to the second input end of the AC / DC converter, the other end of the coil of the third relay is connected to the PLC controller through a fifth drive pin, a normally open contact of the third relay is connected to the secondary side of the isolation transformer, and the other normally open contact is connected to the contactor; one end of the coil of the first relay is connected to the PLC controller through a third drive pin, the other end of the coil of the first relay and the normally open contact are connected to the fourth relay, and the normally closed contact of the first relay is connected to the clamping valve; one end of the coil of the second relay is connected to the PLC controller through a fourth drive pin, the other end of the coil of the second relay and the normally open contact are connected to the fourth relay, and the normally closed contact of the second relay is connected to the opening valve; one end of the coil of the fourth relay is connected to the PLC controller through a sixth drive pin, the other end of the coil of the fourth relay is connected to the other ends of the coils of the first relay and the second relay in sequence, and the normally open contact and the normally closed contact of the fourth relay are both connected to the heating module.

[0009] Optionally, the heating module includes: a thyristor phase-shift trigger and a thyristor, wherein the thyristor phase-shift trigger is used to adjust the conduction angle of the thyristor to control the heating power of the brazing machine.

[0010] Optionally, the phase sequence detection module includes: a trigger, a first clock pin of the trigger is connected to an A-phase detection circuit, a second clock pin of the trigger is connected to a B-phase detection circuit, a reset pin of the trigger is connected to a C-phase detection circuit via a differential circuit, and the A-phase detection circuit, the B-phase detection circuit and the C-phase detection circuit are used to detect the A-phase power supply, the B-phase power supply and the C-phase power supply of the input power supply, respectively.

[0011] Optionally, the A-phase detection circuit includes: a first MOS tube, the control end of the first MOS tube is connected to the A-phase power supply through a first filtering circuit, the first end of the first MOS tube is connected to a +15V power supply through a fourth resistor, and the first end of the first MOS tube is connected to the first clock pin of the trigger, and the second end of the first MOS tube is connected to a first ground end; the first filtering circuit includes a first resistor, a second resistor, a first variable resistor, a first capacitor and a second capacitor, wherein the first end of the first resistor is connected to the A-phase power supply, and the second end is connected to the control end of the first MOS tube; the second resistor and the first variable resistor are connected in series to form a first variable branch, one end of the first variable branch is connected to the first end of the first resistor, and the second end of the first variable branch is connected to the second end of the first MOS tube; the first capacitor and the second capacitor are connected in series and connected in parallel with the first variable branch.

[0012] Optionally, the B-phase detection circuit includes: a second MOS tube, the control end of the second MOS tube is connected to the B-phase power supply through a second filtering circuit, the first end of the second MOS tube is connected to the +15V power supply through an eighth resistor, and the first end of the second MOS tube is connected to the second clock pin of the trigger, and the second end of the second MOS tube is connected to the second ground end; the second filtering circuit includes a fifth resistor, a sixth resistor, a second variable resistor, a third capacitor and a fourth capacitor, wherein the first end of the fifth resistor is connected to the B-phase power supply, and the second end is connected to the control end of the second MOS tube, the sixth resistor and the second variable resistor are connected in series to form a second variable branch, one end of the second variable branch is connected to the first end of the fifth resistor, and the second end of the second variable branch is connected to the second end of the second MOS tube; the third capacitor and the fourth capacitor are connected in series and connected in parallel with the second variable branch.

[0013] Optionally, the C-phase detection circuit includes: a third MOS tube, the control end of the third MOS tube is connected to the C-phase power supply through a third filtering circuit, the first end of the third MOS tube is connected to the +15V power supply through a twelfth resistor, and the first end of the third MOS tube is connected to the second reset end of the trigger through the differential circuit; the second end of the third MOS tube is connected to a third grounding end; the third filtering circuit includes a ninth resistor, a tenth resistor, a third variable resistor, a fifth capacitor and a sixth capacitor, wherein the first end of the ninth resistor is connected to the C-phase power supply, and the second end is connected to the control end of the third MOS tube; the tenth resistor and the third variable resistor are connected in series to form a third variable branch, one end of the third variable branch is connected to the first end of the ninth resistor, and the second end of the third variable branch is connected to the second end of the third MOS tube; the fifth capacitor and the sixth capacitor are connected in series and connected in parallel with the third variable branch.

[0014] Optionally, the differential circuit includes: a seventh capacitor, a thirteenth resistor, a fourteenth resistor and a diode, wherein one end of the seventh capacitor is connected to the first end of the third MOS tube, the other end of the seventh capacitor is connected in series with the diode and then connected to the reset pin of the trigger, the thirteenth resistor and the fourteenth resistor are connected in parallel at both ends of the diode, and the thirteenth resistor is grounded.

[0015] The present application can bring the following beneficial effects: by introducing an isolation module and a heating control module, the present application realizes precise control of the heating power, thereby ensuring the improvement of welding quality and production efficiency; at the same time, by introducing a phase sequence detection module, it can detect the phase sequence of the input power supply in real time and respond to phase sequence errors in a timely manner, thereby effectively preventing the risk of damage to the brazing machine and unstable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural block diagram of a brazing machine control system provided by one embodiment of the present application;

[0017] Figure 2 is a circuit structure diagram of a brazing machine control system provided by another embodiment of the present application;

[0018] Figure 3 It is a structural schematic diagram of a phase sequence detection circuit provided in another embodiment of the present application. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0021] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0023] Figure 1 and Figure 2 FIG. 1 is a structural block diagram and a circuit structure diagram of a brazing machine control system according to an embodiment of the present application. Figure 1 and Figure 2 As shown, the brazing machine control system includes: a main control unit, the main control unit includes an isolation module 100, a control module 200, a heating module 300 and a phase sequence detection module 400, wherein the isolation module is used to isolate the control module from the input power supply; the power supply end of the heating module is connected to the output end of the isolation module to obtain a DC power supply voltage; the first end of the heating module is connected to the A phase of the input power supply, and the second end is connected to the C phase of the input power supply through a transformer, and the heating module is used to control the heating power of the brazing machine based on the control module; the phase sequence detection module is used to detect the phase sequence of the input power supply.

[0024] The present application has made improvements in both heating control and phase sequence detection, which can effectively solve the problems of inaccurate heating control and lack of phase sequence detection mechanism in traditional brazing machine control systems, and enhance the safety, stability and working efficiency of the system.

[0025] In another exemplary embodiment, the isolation module includes: an isolation transformer and an AC / DC converter, wherein the primary side of the isolation transformer is connected to a power switch, the secondary side of the isolation transformer is connected to a first input terminal and a second input terminal of the AC / DC converter through a neutral wire and a live wire, respectively, and the first output terminal and the second output terminal of the AC / DC converter are respectively connected to a voltage pin and a reference voltage pin of the control module.

[0026] In this embodiment, the isolation transformer can provide an electrical isolation layer to isolate the control module from the input power supply, thereby preventing the risk of electric shock or voltage fluctuations caused by direct connection to the input power supply from affecting the control module. By providing an AC / DC converter, the alternating current provided by the input power supply can be converted into direct current, thereby providing a stable +24V DC supply voltage and a 0V reference voltage for the control module, so that the control module can operate stably.

[0027] In another exemplary embodiment, the control module includes a PLC controller, the PLC controller is connected to the first output terminal of the AC / DC converter via a voltage pin, and the PLC controller is connected to the second output terminal of the AC / DC converter via a reference voltage pin.

[0028] In this embodiment, the control module further includes a control switch, which includes an opening button, a start-pause button and a clamping button, wherein the opening button is used to control the opening action of the brazing machine, one end of the opening button is connected to the PLC controller through the third digital input pin (X2 pin), and the other end is connected to the second output end of the AC / DC converter. When the opening button is pressed, a path is formed between the third digital input pin of the PLC controller and the second output end of the AC / DC converter. The PLC controller recognizes the change in the level state on the third digital input pin according to the pre-programmed control logic, and determines that this is a request for an opening operation. In order to perform the opening action, the PLC controller sends a control signal to the second relay K2 through the fourth drive pin (Y3 pin). After the second relay K2 receives the signal from the PLC controller, its coil is energized, causing its normally open contact to close and the normally closed contact to open. As the normally closed contact of the second relay K2 is disconnected, the circuit originally connected to the clamping valve is interrupted, and after the normally open contact is closed, the current reaches the opening valve through the fourth relay K4, prompting the opening valve to open.

[0029] The clamping button is used to control the clamping action of the brazing machine. One end of the clamping button is connected to the PLC controller through the first digital input pin (X0 pin), and the other end is connected to the second output end of the AC / DC converter. When the clamping button is pressed, a low impedance path is formed between the first digital input pin of the PLC controller and the second output end of the AC / DC converter. After the PLC controller detects the change, it will execute the corresponding clamping control logic. Specifically, the PLC controller sends a control signal to the first relay K1 by activating the corresponding output pin (such as the third drive pin Y2). After receiving the signal, the first relay K1 acts, and its normally open contact closes, while the normally closed contact opens. Since the normally closed contact is opened, any other path that may have existed is cut off, and after the normally open contact is closed, the current is allowed to pass through the fourth relay K4 to reach the clamping valve, thereby driving the clamping valve to perform the clamping action.

[0030] One end of the start-pause button is connected to the PLC controller through the second digital input pin (X1 pin), and the other end is connected to the second output end of the AC / DC converter. The second digital input pin receives the corresponding level signal to control the start or stop of the brazing machine. When the start-pause button is pressed, it closes the circuit connected to the second digital input pin of the PLC controller and the second output end of the AC / DC converter, so that the PLC controller detects the state change of the button and executes the corresponding control logic according to the current state of the machine (start or stop). Specifically, when the start-pause button is pressed, the PLC controller detects the change of the input signal through the X1 pin. If the machine is currently in a stopped state, the change of the input signal will be interpreted as a start signal; on the contrary, if the machine is running, the same input signal will be regarded as a pause signal. The program inside the PLC controller will analyze the detected signal and make corresponding processing according to the current working mode (start or stop). For example, if the current state is stopped, the PLC will execute the start logic; if the current state is started, the PLC will execute the pause logic. Once the operation to be performed is determined, the PLC controller will send a control signal to the corresponding output pin. For example, if the machine is to be started, the PLC controller will send a signal to the relay controlling the heating module or other key components to start heating or other necessary startup processes; if the operation is to be suspended, the PLC controller will send a signal to stop heating or any activities in progress.

[0031] In addition, the PLC controller is also connected to a power indicator light, an oil pressure indicator light, a water flow indicator light and a heating indicator light. Specifically, one end of the power indicator light is connected to the first input end of the AC / DC converter, and the other end is connected to the first output end of the AC / DC converter. The power indicator light is usually used to display the on / off state of the power supply. When one end of the power indicator light is connected to the first output end of the AC / DC converter, and the other end is connected to the second output end of the AC / DC converter, a complete circuit loop is formed between them. When the circuit is powered on, the current flows from the live wire through the power indicator light, and then flows back to the power supply through the neutral wire, so that the power indicator light can light up, thereby clearly indicating that the power is on.

[0032] One end of the oil pressure indicator light is connected to the first output end of the AC / DC converter, and the other end is connected to the PLC controller through the fourth digital input pin (X3 pin), and the connecting line between the fourth digital input pin and the oil pressure indicator light is also connected to an oil pressure switch. When the oil pressure is normal, the oil pressure switch is closed, and current flows into the PLC controller through the fourth digital input pin, and the oil pressure indicator light is on; when the oil pressure is abnormal, the oil pressure switch is disconnected, no current flows into the PLC controller, and the oil pressure indicator light is off.

[0033] One end of the water flow indicator light is connected to the first output end of the AC / DC converter, and the other end is connected to the second output end of the AC / DC converter through the water flow switch. When the water flow switch is closed, the current flows through the first output end of the AC / DC converter through the water flow indicator light, and then flows back to the second output end of the AC / DC converter through the water flow switch, forming a closed loop, so that the water flow indicator light lights up. If the water flow switch is disconnected, the current cannot form a loop, and the water flow indicator light goes out, thereby ensuring the safety of the circuit. The above design can effectively indicate whether there is water flowing through the system, and ensures the safety of the circuit through a simple switching mechanism.

[0034] One end of the heating indicator light is connected to the first output end of the AC / DC converter, and the other end is connected to the PLC controller through the second drive pin (Y1 pin). The PLC controller can determine whether the heating indicator light is on by controlling the state of the Y1 pin (for example, high or low level). When the PLC controller activates the Y1 pin, the heating indicator light will light up, indicating that the heating system is working or has reached a certain state. Conversely, if the PLC controller does not activate the Y1 pin, the heating indicator light will go out. This method allows the PLC controller to control the state of the heating indicator light by outputting a signal, thereby indicating the operating status of the heating system.

[0035] The PLC controller is also connected to a temperature sensor, one end of which is connected to the PLC controller via a +5V pin, and the other end is connected to the first ground pin GND1 of the PLC controller. The temperature sensor usually requires a stable voltage source to power it so that it can normally measure the temperature and convert it into an electrical signal. In this embodiment, the +5V pin of the PLC controller provides this stable voltage source. At the same time, the other end of the temperature sensor is connected to the first ground pin GND1, forming a complete circuit loop so that current can flow.

[0036] The PLC controller is also connected to a buzzer, one end of which is connected to the PLC controller via a first drive pin (Y0 pin), and the other end of which is connected to the first output end of the AC / DC converter. When the PLC controller activates the Y0 output pin, a closed circuit is formed between the Y0 pin and the first output end of the AC / DC converter, so that the buzzer is powered on and emits a sound.

[0037] The PLC controller is also connected to a first relay K1, a second relay K2, a third relay K3 and a fourth relay K4, respectively, wherein one end of the coil of the third relay K3 is connected to the second input end of the AC / DC converter, the other end of the coil of the third relay K3 is connected to the PLC controller via a fifth drive pin (Y4 pin), one normally open contact of the third relay K3 is connected to the secondary side of the isolation transformer, and the other normally open contact is connected to the contactor; one end of the coil of the first relay K1 is connected to the PLC controller via a third drive pin (Y2 pin), the other end of the coil of the first relay K1 and the normally open contact are connected to the fourth Relay K4, the normally closed contact of the first relay K1 is connected to the clamping valve; one end of the coil of the second relay K2 is connected to the PLC controller through the fourth drive pin (Y3 pin), the other end of the coil of the second relay K2 and the normally open contact are connected to the fourth relay K4, and the normally closed contact of the second relay K2 is connected to the opening valve; one end of the coil of the fourth relay K4 is connected to the PLC controller through the sixth drive pin (Y5 pin), the other end of the coil of the fourth relay K4 is connected to the other ends of the coils of the first relay K1 and the second relay K2 in sequence, and the normally open contact and the normally closed contact of the fourth relay are both connected to the heating module.

[0038] When the PLC controller outputs a signal to the Y2 pin, the first relay K1 will be activated, thereby controlling the switching state of the clamping valve to achieve the clamping operation of the workpiece.

[0039] When the workpiece needs to be released, the PLC controller sends a signal to the Y3 pin, and the second relay K2 is actuated to control the opening valve to open and release the workpiece.

[0040] The third relay K3 controls the action of the contactor, and the contactor can be used to control the start and stop of the electric hoist, the water pump and the oil pump.

[0041] The fourth relay K4 corresponds to the pin 4, pin 3, pin 2 and pin 1 of the thyristor. The relay K4 plays an important role in connecting the PLC controller and the thyristor in the brazing machine control system. When the PLC controller needs to adjust the output of the thyristor, it will generate a control signal at the Y5 pin. This signal is usually a digital signal, indicating that the circuit needs to be turned on or off. After receiving the digital signal from the PLC controller, the contacts of the relay K4 will be closed or disconnected according to the indication of the signal. When closed, the contacts of the relay K4 connect the corresponding pins of the thyristor (pin 4, pin 3, pin 2 and pin 1) to form a circuit path; when disconnected, the circuit path is cut off. After the pins of the thyristor receive the signal from the relay K4, they will adjust their internal working state according to the voltage, current and other parameters between the pins, thereby changing the trigger angle or conduction state of the thyristor, thereby directly affecting the current passing through the thyristor, and then controlling the heating power of the heating element. By adjusting the trigger angle or conduction state of the thyristor, the heating power of the heating element can be controlled, thereby achieving precise control of the welding temperature of the brazing machine (this is because the heating power of the heating element is proportional to the current passing through it, and the thyristor achieves power control by adjusting the current).

[0042] It should be noted that in this embodiment, a contactor is provided between the third relay K3 and the electric hoist, oil pump and water pump, the purpose of which is to achieve remote control and protection of the electric hoist, oil pump and water pump. Specifically, the contactor has the following important functions:

[0043] 1. Through the signal sent by the PLC controller, the contactor can realize the opening or closing operation of the electric hoist, oil pump and water pump at a long distance. In this way, the operator can complete the control task without direct contact with the equipment, thereby improving the safety and convenience of operation.

[0044] 2. Contactors are used to frequently connect and disconnect circuits, which is especially important for equipment that needs to be started and stopped frequently (such as electric hoists, oil pumps, and water pumps). The frequent operation of contactors will not cause wear like ordinary switches, so they have a longer service life.

[0045] 3. Contactors are usually equipped with overload protection devices. When the load current exceeds a predetermined value, the contactor automatically disconnects the circuit, thereby protecting the equipment from overload damage. This is essential for protecting motors and other key equipment, helping to extend equipment life and reduce maintenance costs.

[0046] 4. The contactor can also play a certain isolation role, that is, when the equipment is repaired or replaced, the power supply can be isolated by disconnecting the contactor to ensure the safety of the maintenance personnel.

[0047] In another exemplary embodiment, the heating module includes: a thyristor phase-shift trigger and a thyristor, wherein the thyristor phase-shift trigger is used to adjust the conduction angle of the thyristor to control the heating power of the brazing machine.

[0048] In this embodiment, the vin pin of the thyristor phase-shift trigger is connected to the analog output pin (DA0 pin) of the PLC controller. The PLC controller sends an analog signal to the thyristor phase-shift trigger through the DA0 pin. The thyristor phase-shift trigger can adjust its trigger angle according to the received signal, thereby adjusting the conduction angle of the thyristor. When the thyristor receives the control signal sent by the thyristor phase-shift trigger, it will adjust its conduction angle according to the signal instruction, thereby controlling the current flowing through the three-phase power supply and realizing the adjustment of the welding power.

[0049] The thyristor phase-shift trigger also includes a K1 pin (representing the anode of the thyristor, which is the main current inflow port of the thyristor. When the thyristor is triggered to turn on, the current will flow in from here), a G1 pin (the gate of the thyristor, also called the trigger pole. By applying a trigger voltage or current between G1 and the corresponding cathode, the thyristor can be triggered from the cut-off state to the on state), a K2 pin (similar to K1, it is also one of the anodes of the thyristor) and a G2 pin (similar to G1, it is another gate or trigger pole of the thyristor, used to trigger the conduction of the thyristor). The K1 pin, the G1 pin, the K2 pin and the G2 pin are connected to the pin 4, the pin 3, the pin 2 and the pin 1 on the thyristor. Through the connection of these pins, the thyristor phase-shift trigger can control the conduction and shutdown of the thyristor, thereby adjusting the heating power. Specifically, when the PLC controller sends an analog signal to the thyristor phase-shift trigger through the DA0 pin, the thyristor phase-shift trigger will adjust the conduction angle of the thyristor according to this signal. By adjusting the conduction angle, the current through the thyristor can be controlled, thereby achieving precise control of the heating power of the heating element. For example, assuming that the PLC controller wants to increase the heating power of the heating element, it will send a higher analog signal through the DA0 pin (for example, a voltage signal close to the maximum value, assuming that the analog output range of the PLC controller is from 0V to 10V, then the higher analog signal can be 10V*90%, that is, 9V). After receiving this higher voltage signal, the thyristor phase-shift trigger will adjust its internal trigger mechanism to turn on the thyristor at an earlier moment. This means that within an AC cycle, the thyristor is turned on for a longer time, thereby allowing more current to flow through the thyristor to the heating element, and the heating power increases accordingly.

[0050] On the contrary, if the PLC controller wants to reduce the heating power, for example, to 20% of the maximum power, it will send a lower analog signal through the DA0 pin (for example, a voltage signal close to the minimum value, assuming that the analog output range of the PLC controller is from 0V to 10V, then the lower analog signal can be 10V*20%, that is, 2V). After receiving this lower voltage signal, the thyristor phase-shift trigger will delay the turn-on time of the thyristor, so that the turn-on time of the thyristor in one AC cycle is reduced. As a result, the current flowing through the thyristor is reduced, and the heating power of the heating element is also reduced.

[0051] For example, if the PLC controller needs to set the power of the heating element to 50% of the maximum value, it will send an analog signal representing half the amplitude to the thyristor phase-shift trigger. After receiving the analog signal, the thyristor phase-shift trigger will trigger the thyristor to start conducting at the midpoint of each AC cycle until the cycle ends. In this way, the thyristor is only in the conducting state for half of the time in each cycle, and the heating element receives half of the maximum power.

[0052] The first output end of the thyristor is connected to the A-phase power supply of the input power supply, and the second output end of the thyristor is connected to the C-phase power supply of the input power supply through the primary side of the transformer and connected to electrode 1 and electrode 2 through the secondary side of the transformer. Electrode 1 and electrode 2 are working electrodes in the welding process, and the current flow between them will generate heat, thereby realizing the welding operation. When the thyristor receives the control signal from the thyristor phase-shift trigger, it will adjust the conduction angle according to the instruction of the signal, thereby controlling the current flowing through the A-phase power supply to achieve the adjustment of the welding power.

[0053] In summary, the thyristor plays a vital role in the brazing machine control system. It receives the control signal from the thyristor phase-shift trigger and is connected to the A-phase power supply and C-phase power supply of the input power supply and the working electrode, thereby achieving precise control of the current and voltage during the welding process.

[0054] In another exemplary embodiment, Figure 3 As shown, the phase sequence detection module includes: a trigger, a first clock pin of the trigger is connected to an A-phase detection circuit, a second clock pin of the trigger is connected to a B-phase detection circuit, a reset pin of the trigger is connected to a C-phase detection circuit via a differential circuit, and the A-phase detection circuit, the B-phase detection circuit and the C-phase detection circuit are respectively used to detect the A-phase power supply, the B-phase power supply and the C-phase power supply of the input power supply.

[0055] In this embodiment, the A-phase detection circuit is connected to the A-phase power supply of the input power supply, and the A-phase detection circuit includes a first MOS transistor Q1, the control end (gate) of the first MOS transistor Q1 is connected to the A-phase power supply through a first filter circuit, the first end (drain) of the first MOS transistor Q1 is connected to the +15V power supply through a fourth resistor R4, and the first end (drain) of the first MOS transistor Q1 is connected to the first clock pin 1CLK of the trigger, and the second end (source) of the first MOS transistor Q1 is connected to the first ground terminal GND1. The first filter circuit includes a first resistor R1, a second resistor R2, a first variable resistor R3, a first capacitor C1 and a second capacitor C2, wherein the first end of the first resistor R1 is connected to the A-phase power supply, and the second end is connected to the control end of the first MOS transistor Q1, the second resistor R2 and the first variable resistor R3 are connected in series to form a first variable branch, one end of the first variable branch is connected to the first end of the first resistor R1, and the second end of the first variable branch is connected to the second end of the first MOS transistor Q1; the first capacitor C1 and the second capacitor C2 are connected in series and connected in parallel with the first variable branch.

[0056] The B-phase detection circuit is connected to the B-phase power supply of the input power supply, and the B-phase detection circuit includes a second MOS tube Q2, the control end (gate) of the second MOS tube Q2 is connected to the B-phase power supply through the second filter circuit, the first end (drain) of the second MOS tube Q2 is connected to the +15V power supply through the eighth resistor R8, and the first end (drain) of the second MOS tube Q2 is connected to the second clock pin 2CLK of the trigger, and the second end (source) of the second MOS tube Q2 is connected to the second ground terminal GND2. The second filter circuit includes a fifth resistor R5, a sixth resistor R6, a second variable resistor R7, a third capacitor C3 and a fourth capacitor C4, wherein the first end of the fifth resistor R5 is connected to the B-phase power supply, and the second end is connected to the control end of the second MOS tube Q2, the sixth resistor R6 and the second variable resistor R7 are connected in series to form a second variable branch, one end of the second variable branch is connected to the first end of the fifth resistor R5, and the second end of the second variable branch is connected to the second end of the second MOS tube Q2; the third capacitor C3 and the fourth capacitor C4 are connected in series and connected in parallel with the second variable branch.

[0057] The C-phase detection circuit is connected to the C-phase power supply of the input power supply, and the C-phase detection circuit includes a third MOS tube Q3. The control end (gate) of the third MOS tube Q3 is connected to the C-phase power supply through a third filtering circuit. The first end (drain) of the third MOS tube Q3 is connected to the +15V power supply through a twelfth resistor R12, and the first end (drain) of the third MOS tube Q3 is connected to the second reset end 2R of the trigger through the differential circuit. The second end (source) of the third MOS tube Q3 is connected to the third ground end GND3. The third filtering circuit includes a ninth resistor R9, a tenth resistor R10, a third variable resistor R11, a fifth capacitor C5 and a sixth capacitor C6, wherein a first end of the ninth resistor R9 is connected to the C-phase power supply, and a second end is connected to the control end (gate) of the third MOS tube Q3; the tenth resistor R10 and the third variable resistor R11 are connected in series to form a third variable branch, one end of the third variable branch is connected to the first end of the ninth resistor R9, and a second end of the third variable branch is connected to the second end (source) of the third MOS tube Q3; the fifth capacitor C5 and the sixth capacitor C6 are connected in series and connected in parallel with the third variable branch.

[0058] In the phase sequence detection module, when the voltage of the A-phase and B-phase power supplies changes, clock-related signals will be generated through their respective detection circuits, and these signals are sent to the clock pin of the trigger. The change of the C-phase power supply generates a short pulse signal through the differential circuit, which is used to reset the trigger. Specifically, when the phase sequence of the three-phase power supply is correct, the voltage change of the A-phase and B-phase power supplies will generate clock-related signals through their respective detection circuits, and these signals are sent to the clock pin of the trigger. The change of the C-phase power supply generates a short pulse signal through the differential circuit, which is used to reset the trigger. If the phase sequence of the three-phase power supply is correct, the trigger will be triggered by the clock signal in the correct order and reset at the appropriate time. On the contrary, if the phase sequence is wrong, the operation of the trigger will not meet expectations, so it can be detected and corresponding measures can be taken, such as alarming or cutting off the power supply. Exemplarily, under the correct phase sequence condition, the voltage changes of the A-phase, B-phase and C-phase power supplies are:

[0059] Phase A power supply voltage changes: rises after 10ms

[0060] Phase B power supply voltage changes: rises after 20ms

[0061] Phase C power supply voltage changes: rises after 30ms

[0062] In this case, the signals generated by the power supply voltage changes of phases A and B trigger the clock pin of the flip-flop after 10ms and 20ms respectively. The signal generated by the power supply voltage change of phase C triggers the reset pin of the flip-flop after 30ms. Therefore, the flip-flop is triggered by the clock signal at 10ms and 20ms, and is reset at 30ms, indicating that the phase sequence is correct.

[0063] Under the condition of wrong phase sequence, the voltage changes of phase A, phase B and phase C power supply are:

[0064] Phase A power supply voltage changes: rises after 10ms

[0065] Phase B power supply voltage changes: rises after 25ms

[0066] Phase C power supply voltage changes: rises after 35ms

[0067] If the phase sequence is wrong, for example, the B-phase power supply voltage change time is later than the normal 20ms, but delayed to 25ms, and the C-phase power supply voltage change time is also delayed to 35ms. In this case, the trigger will not be triggered and reset according to the expected timing. For example, the signal generated by the A-phase power supply voltage change triggers the trigger's clock pin after 10ms, but the signal of the B-phase power supply voltage change arrives after 25ms, which exceeds the normal time interval. At the same time, the signal generated by the C-phase power supply voltage change triggers the reset pin of the trigger after 35ms, which makes the operation of the trigger not meet the expected timing.

[0068] In the above example of phase sequence error, the trigger failed to reset at the expected time because the timing of the B-phase and C-phase power supply voltage changes deviated from the normal timing. At this time, the phase sequence detection module can trigger an alarm signal to inform the user that the power phase sequence is wrong. In addition, the system can also be configured to automatically cut off the power supply to prevent the device from operating under the wrong phase sequence conditions and avoid potential risks.

[0069] It should be noted that, taking the A-phase detection circuit as an example, in the A-phase detection circuit, the first variable branch formed by the second resistor R2 and the first variable resistor R3 connected in series is connected in parallel with the first capacitor C1 and the second capacitor C2 connected in series, in order to achieve the following technical effects:

[0070] 1. The first capacitor C1 and the second capacitor C2 are connected in series to form a low-pass filter, which can effectively filter out high-frequency noise. When the signal passes through, the high-frequency component will be bypassed by the capacitor, thereby ensuring that the signal transmitted to the first MOS tube Q1 is purer.

[0071] 2. The second resistor R2 and the first variable resistor R3 can adjust the amplitude of the signal by being connected in series. By adjusting the first variable resistor R3, different input signal strengths can be adapted to ensure that the signal has been adjusted to a suitable level before entering the first MOS tube Q1, which helps to improve the detection accuracy and enable the system to better adapt to power supply conditions in different environments.

[0072] For example, assuming that the input signal ranges from 0V to 10V, the signal needs to be adjusted to a level suitable for the operation of the first MOS transistor Q1 according to different working conditions. The signal amplitude can be adjusted by changing the resistance value of the first variable resistor R3.

[0073] Test scenario 1: Low input signal strength

[0074] Input signal: 2V

[0075] The first variable resistor R3 is initially set to 1KΩ

[0076] Adjusted signal: 2V (because the signal itself is weak, no further adjustment is required)

[0077] By adjusting the first variable resistor R3 to a lower resistance, such as 500Ω, the signal amplitude can be further increased to ensure that the signal is adjusted to a suitable level before entering the MOS tube Q1.

[0078] Test scenario 2: Medium input signal strength

[0079] Input signal: 5V

[0080] The first variable resistor R3 is initially set to 1KΩ

[0081] Adjusted signal: 5V (medium signal strength, can adapt to the current settings)

[0082] If the signal strength is still too weak or too strong, the signal strength can be optimized by further adjusting the resistance of the first variable resistor R3. For example, increasing the resistance of R3 to 2KΩ can weaken the signal, and reducing the resistance of R3 to 500Ω can enhance the signal.

[0083] Test scenario three: high input signal strength

[0084] Input signal: 8V

[0085] The first variable resistor R3 is initially set to 1KΩ

[0086] Adjusted signal: 8V (strong signal may cause unstable operation of MOS tube Q1)

[0087] In this case, the resistance of the first variable resistor R3 may need to be increased, for example, adjusted to 2KΩ, so as to reduce the signal strength to make it suitable for the working condition of the MOS tube Q1.

[0088] In summary, by adjusting the first variable resistor R3, the signal can be adjusted to a suitable level according to the requirements of different input signal strengths, ensuring that the signal has been adjusted to a suitable level before entering the MOS tube Q1. This not only helps to improve the detection accuracy, but also enables the system to better adapt to power supply conditions in different environments. In addition, this adjustment also helps to protect the MOS tube Q1 from being damaged due to excessive signal strength.

[0089] 3. The structure formed by the first capacitor C1 and the second capacitor C2 in parallel with the resistors R2 and R3 can also play a protective role. When the input voltage fluctuates abnormally, the capacitor can absorb these fluctuations to prevent the MOS tube Q1 from being damaged. In addition, by adjusting the variable resistor R3, the input impedance of the entire circuit can also be adjusted to match different power supply characteristics, further enhancing the robustness of the circuit.

[0090] 4. Dynamic range adjustment: The presence of the first variable resistor R3 allows the circuit sensitivity to be adjusted according to actual needs. For example, in some cases, it may be necessary to respond to small voltage changes, while in other cases, it may be necessary to ignore these small changes. By adjusting the first variable resistor R3, the circuit's response threshold to voltage changes can be flexibly set.

[0091] It should be further explained that in the A-phase detection circuit, if only the first capacitor C1 is used, although part of the high-frequency noise can be filtered out, the filtering effect is limited, especially in a complex electromagnetic environment, it is difficult to achieve an ideal filtering effect by only using the first capacitor C1. The first capacitor C1 and the second capacitor C2 connected in series can filter out noise more effectively, and by adjusting the parameters of the two capacitors, noise suppression in a wider frequency band can be achieved. In addition, if the first variable resistor R3 is not set, the A-phase detection circuit will lose the ability to adjust the signal amplitude. In practical applications, the power supply signal may fluctuate or be noisy, and the first variable resistor R3 can adjust the signal strength by adjusting its resistance value to meet the needs under different working conditions. Without the first variable resistor R3, the A-phase detection circuit cannot effectively cope with the situation of different input signals, resulting in inaccurate detection. In addition, in the absence of the first variable resistor R3, the protection function of the A-phase detection circuit will also be limited. The first variable resistor R3 can not only adjust the signal amplitude, but also serve as a part of the protection device to limit the current flowing into the first MOS tube Q1 by adjusting its resistance, thereby protecting the first MOS tube from the impact of excessive current. If the first variable resistor R3 is missing, the A-phase detection circuit may be more vulnerable to damage.

[0092] The differential circuit includes a seventh capacitor C7, a thirteenth resistor R13, a fourteenth resistor R14 and a diode D, one end of the seventh capacitor C7 is connected to the first end (drain) of the third MOS tube Q3, the other end of the seventh capacitor C7 is connected in series with the diode D and then connected to the reset pin 2R of the trigger, the thirteenth resistor R13 and the fourteenth resistor R14 are connected in parallel at both ends of the diode D, and the thirteenth resistor R13 is grounded.

[0093] The working principle of the differential circuit is described as follows: when the C-phase power supply voltage is in a stable state, the seventh capacitor C7 is charged with a steady-state voltage, and the diode D is in a cut-off state; when the C-phase power supply voltage suddenly rises, the seventh capacitor C7 does not have time to charge quickly, so there will be an instantaneous voltage difference at both ends, and this voltage difference will flow to the thirteenth resistor R13 and the fourteenth resistor R14 connected in parallel through the diode D. Since the resistor R13 is grounded, at this moment, a current will flow to the ground through the diode D and the thirteenth resistor R13, thereby generating a short high-level pulse at both ends of the fourteenth resistor R14, and this high-level pulse is sent to the reset pin 2R of the trigger, so that the trigger is reset.

[0094] In summary, the differential circuit can generate a pulse for resetting the trigger when the phase sequence is correct by detecting the change of the C phase power supply voltage, ensuring that the trigger can work according to the correct timing. If the phase sequence is wrong, the trigger will not be reset correctly, so the phase sequence problem can be detected.

[0095] like Figure 3 As shown, the main output pin 2Q of the trigger is also connected to the fifteenth resistor R15 and the eighth capacitor C8 in series, and the eighth capacitor C8 is grounded. The fifteenth resistor R15 and the eighth capacitor C8 form an RC filter, which allows lower frequency signals to pass through, while higher frequency noise is attenuated. This filtering helps to ensure the stability of the trigger output signal and avoid malfunctions due to power supply fluctuations or interference. In addition, the RC filter can also be used to delay or shape the output signal to ensure that the signal received by the subsequent circuit is clean and stable, thereby improving the reliability and performance of the system.

[0096] In another exemplary embodiment, the system further includes a transformer for measuring the magnitude of a current passing through the thyristor.

[0097] In this embodiment, the transformer is connected to an ammeter, and the current passing through the thyristor will generate a magnetic field in the primary winding of the transformer, and this magnetic field will induce a smaller current in the secondary winding of the transformer. The current of the secondary winding can be directly connected to an ammeter or other measuring device for reading. In this way, even if the thyristor handles a large current, it can be safely measured through the transformer without worrying about damage to the ammeter or causing a safety accident. In addition, the data collected by the transformer can also be used for feedback control. For example, in the control system of a brazing machine, monitoring the current can help adjust the working state of the thyristor and ensure the stability and quality of the welding process.

[0098] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A brazing machine control system, characterized in that: The brazing machine control system is connected to an external input power supply, and the brazing machine control system comprises: The main control unit includes an isolation module, a control module, a heating module and a phase sequence detection module, wherein: The isolation module is used to isolate the control module from the input power supply; The power supply end of the heating module is connected to the output end of the isolation module to obtain a DC power supply voltage; the first end of the heating module is connected to the A phase of the input power supply, and the second end is connected to the C phase of the input power supply through a transformer. The heating module is used to control the heating power of the brazing machine based on the control module; The phase sequence detection module is used to detect the phase sequence of the input power supply.

2. The brazing machine control system according to claim 1, characterized in that: The isolation module comprises: Isolation transformer and AC / DC converter, where The primary side of the isolation transformer is connected to the power switch, and the secondary side of the isolation transformer is connected to the control module through the AC / DC converter. The AC / DC converter is used to convert the alternating current provided by the input power source into direct current that can be used by the control module.

3. The brazing machine control system according to claim 2, characterized in that: The control module comprises: PLC controller, The PLC controller is connected to the first output end of the AC / DC converter via a voltage pin, and the PLC controller is connected to the second output end of the AC / DC converter via a reference voltage pin.

4. The brazing machine control system according to claim 3, characterized in that: The control module also includes: A first relay, a second relay, a third relay and a fourth relay, wherein, One end of the coil of the third relay is connected to the second input end of the AC / DC converter, the other end of the coil of the third relay is connected to the PLC controller through a fifth drive pin, one normally open contact of the third relay is connected to the secondary side of the isolation transformer, and the other normally open contact is connected to the contactor; One end of the coil of the first relay is connected to the PLC controller via a third driving pin, the other end of the coil of the first relay and a normally open contact are connected to the fourth relay, and the normally closed contact of the first relay is connected to the clamping valve; One end of the coil of the second relay is connected to the PLC controller via a fourth drive pin, the other end of the coil of the second relay and a normally open contact are connected to the fourth relay, and the normally closed contact of the second relay is connected to the opening valve; One end of the coil of the fourth relay is connected to the PLC controller via the sixth drive pin, the other end of the coil of the fourth relay is connected to the other ends of the coils of the first relay and the second relay in sequence, and the normally open contact and the normally closed contact of the fourth relay are both connected to the heating module.

5. The brazing machine control system according to claim 1, characterized in that: The heating module comprises: Thyristor phase-shift trigger and thyristor, where The thyristor phase-shift trigger is used to adjust the conduction angle of the thyristor to control the heating power of the brazing machine.

6. The brazing machine control system according to claim 1, characterized in that: The phase sequence detection module comprises: A trigger, wherein the first clock pin of the trigger is connected to an A-phase detection circuit, the second clock pin of the trigger is connected to a B-phase detection circuit, the reset pin of the trigger is connected to a C-phase detection circuit via a differential circuit, and the A-phase detection circuit, the B-phase detection circuit and the C-phase detection circuit are used to detect the A-phase power supply, the B-phase power supply and the C-phase power supply of the input power supply, respectively.

7. The brazing machine control system according to claim 6, characterized in that: The A phase detection circuit comprises: A first MOS tube, wherein the control end of the first MOS tube is connected to the A-phase power supply through a first filtering circuit, the first end of the first MOS tube is connected to a +15V power supply through a fourth resistor, and the first end of the first MOS tube is connected to the first clock pin of the trigger, and the second end of the first MOS tube is connected to a first ground end; the first filtering circuit comprises a first resistor, a second resistor, a first variable resistor, a first capacitor, and a second capacitor, wherein the first end of the first resistor is connected to the A-phase power supply, and the second end is connected to the control end of the first MOS tube; the second resistor and the first variable resistor are connected in series to form a first variable branch, one end of the first variable branch is connected to the first end of the first resistor, and the second end of the first variable branch is connected to the second end of the first MOS tube; the first capacitor and the second capacitor are connected in series to be connected in parallel with the first variable branch.

8. The brazing machine control system according to claim 6, characterized in that: The B-phase detection circuit comprises: A second MOS tube, wherein the control end of the second MOS tube is connected to the B-phase power supply through a second filtering circuit, the first end of the second MOS tube is connected to a +15V power supply through an eighth resistor, and the first end of the second MOS tube is connected to the second clock pin of the trigger, and the second end of the second MOS tube is connected to a second ground end; the second filtering circuit comprises a fifth resistor, a sixth resistor, a second variable resistor, a third capacitor and a fourth capacitor, wherein the first end of the fifth resistor is connected to the B-phase power supply, and the second end is connected to the control end of the second MOS tube, the sixth resistor and the second variable resistor are connected in series to form a second variable branch, one end of the second variable branch is connected to the first end of the fifth resistor, and the second end of the second variable branch is connected to the second end of the second MOS tube; the third capacitor and the fourth capacitor are connected in series and connected in parallel with the second variable branch.

9. The brazing machine control system according to claim 6, characterized in that: The C phase detection circuit comprises: a third MOS tube, wherein the control end of the third MOS tube is connected to the C-phase power supply through a third filtering circuit, the first end of the third MOS tube is connected to the +15V power supply through a twelfth resistor, and the first end of the third MOS tube is connected to the second reset end of the trigger through the differential circuit; the second end of the third MOS tube is connected to a third grounding end; the third filtering circuit comprises a ninth resistor, a tenth resistor, a third variable resistor, a fifth capacitor and a sixth capacitor, wherein the first end of the ninth resistor is connected to the C-phase power supply, and the second end is connected to the control end of the third MOS tube; the tenth resistor and the third variable resistor are connected in series to form a third variable branch, one end of the third variable branch is connected to the first end of the ninth resistor, and the second end of the third variable branch is connected to the second end of the third MOS tube; the fifth capacitor and the sixth capacitor are connected in series to be connected in parallel with the third variable branch.

10. The brazing machine control system according to claim 9, characterized in that: The differentiator circuit comprises: a seventh capacitor, a thirteenth resistor, a fourteenth resistor and a diode, in, One end of the seventh capacitor is connected to the first end of the third MOS tube, the other end of the seventh capacitor is connected in series with the diode and then connected to the reset pin of the trigger, the thirteenth resistor and the fourteenth resistor are connected in parallel at both ends of the diode, and the thirteenth resistor is grounded.

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