A VRD-combined anti-sticking strip circuit and method for welding machine

Abstract

The present application discloses a VRD-based anti-sticking strip circuit and method for welding machines, which relates to the technical field of inverter welding machines. The circuit includes: a port detection module connected to the welding machine output port, used to detect whether the welding machine output port is short-circuited, and outputs a first signal when the welding machine output port is detected to be short-circuited; a PWM control module connected to the welding machine output port, used to adjust the output voltage and output current of the welding machine output port; an anti-sticking and VRD module, used to receive the first signal and respond to the first signal to output a second signal to the PWM control module; the PWM control module receives the second signal and responds to the second signal to reduce the output current until it is lower than a preset current threshold. The present application has the effect of not needing to restart the inverter welding machine when the welding rod is adhered to the workpiece, thereby reducing the loss of circuit components in the inverter welding machine.

Description

Technical Field

[0001] The present application relates to the technical field of inverter welding machines, and in particular to an anti-sticking strip circuit and method combined with a VRD for a welding machine. Background Art

[0002] The inverter welding machine is composed of an inverter power supply and external devices. The inverter power supply is the core of the inverter welding machine, and its working process is: industrial frequency AC-DC-high frequency AC-transformation-DC, which is to rectify and filter the three-phase or single-phase 50Hz industrial frequency AC to obtain a smoother DC power. The inverter circuit composed of IGBT or field effect tube converts the DC power into 15-100kHz AC power, and after the medium frequency main transformer steps down, it is rectified and filtered again to obtain a stable DC output welding current (or inverter outputs the AC power of the required frequency again).

[0003] When using an inverter welding machine for welding, sometimes the welding rod and the workpiece may be directly short-circuited and sticky due to the poor handling of the welding rod end or the poor handling of the welding workpiece. If the instantaneous current is large at this time, the welding rod may turn red or the coating may fall off. If the welding rod is forcibly disconnected from the workpiece during adhesion, the workpiece may be damaged. There may also be a relatively large arc current at the moment of disconnection, which may easily damage the workpiece or welding rod. Therefore, when the welding rod and the workpiece are stuck, it is usually necessary to turn off the inverter welding machine so that the output current of the welding head drops to 0. At this time, the welding rod is easy to separate from the workpiece. After the welding rod and the workpiece are separated, restart the inverter welding machine.

[0004] With respect to the above-mentioned related technologies, the inventors believe that there are the following defects: when using an inverter welding machine to weld a relatively rough welding workpiece, adhesion is prone to occur. If the inverter welding machine is restarted every time adhesion occurs, the circuit components in the inverter welding machine will be greatly damaged. Summary of the invention

[0005] In order to improve the defect that restarting the inverter welding machine each time the adhesion phenomenon occurs causes large losses to the circuit components in the inverter welding machine, the present application provides an anti-sticking strip circuit and method combined with VRD for a welding machine.

[0006] In a first aspect, the present application provides an anti-sticking strip circuit combined with a VRD for a welding machine, the circuit comprising:

[0007] A port detection module, connected to the output port of the welding machine, for detecting whether the output port of the welding machine is short-circuited, and outputting a first signal when a short-circuit is detected in the output port of the welding machine;

[0008] A PWM control module, connected to the welding machine output port, for adjusting the output voltage and output current of the welding machine output port;

[0009] an anti-sticking and VRD module, configured to receive the first signal and output a second signal to the PWM control module in response to the first signal;

[0010] The PWM control module receives the second signal and reduces the output current to below a preset current threshold in response to the second signal.

[0011] By adopting the above technical solution, the welding rod is connected to the output port of the welding machine. When the welding rod is adhered to the workpiece, the output port of the welding machine will be short-circuited. Therefore, the port detection module can be used to detect whether the output port of the welding machine is short-circuited. If a short circuit is detected, a first signal is output to the anti-sticking and VRD module. After receiving the first signal, the anti-sticking and VRD module outputs a second signal to the PWM control module, so that the PWM control module reduces the output current of the output end of the welding machine until it is lower than the preset current threshold. Therefore, the welding rod can be separated from the workpiece conveniently without restarting the welding machine, thereby avoiding damage to circuit components in the welding machine due to frequent restarts of the welding machine.

[0012] Optionally, the port detection module includes a first diode D1, a first voltage-stabilizing diode Z1, a first electrolytic capacitor E1, a first capacitor C1, a first resistor R1, a second resistor R2, a third resistor R3 and a first light-emitting diode UA1, the positive electrode of the first diode D1 is connected to the positive electrode of the welding machine output port, the negative electrode of the first diode D1 is connected to one end of the first resistor R1, one end of the first resistor R1 is respectively connected to one end of the first electrolytic capacitor E1, the first capacitor C1, the first voltage-stabilizing diode Z1 and the second resistor R2, the other ends of the first electrolytic capacitor E1, the first capacitor C1 and the first voltage-stabilizing diode Z1 are all grounded, the other end of the second resistor R2 is respectively connected to the positive electrode of the third resistor R3 and the first light-emitting diode UA1, the negative electrodes of the third resistor R3 and the first light-emitting diode UA1 are grounded, and the first light-emitting diode UA1 is used to send the first signal.

[0013] By adopting the above technical solution, since the welding current output by the welding machine output port may be alternating current, the welding current can be rectified into direct current through the first diode D1, and then filtered through the first electrolytic capacitor E1 and the first capacitor C1. The first voltage stabilizing diode Z1 can play a role in voltage stabilization. When the welding current is normal, the first light-emitting diode UA1 will not emit light, but when the welding machine output port is short-circuited, the current will suddenly increase. At this time, due to the increase in current, the first light-emitting diode UA1 will emit light to send a first signal, and the third resistor R3 can play a role in shunt protection when the current suddenly increases.

[0014] Optionally, the anti-adhesion and VRD module includes an anti-adhesion sub-module, a VRD sub-module and a second light-emitting diode UA2, the VRD sub-module includes a VRD control switch, the anti-adhesion sub-module and the VRD sub-module are both connected to the positive electrode of the second light-emitting diode UA2, the negative electrode of the second light-emitting diode UA2 is grounded, the anti-adhesion sub-module is used to receive the first signal and respond to the first signal to make the second light-emitting diode UA2 emit the second signal, when the VRD control switch is turned on, the VRD sub-module will control the second light-emitting diode UA2 to emit the second signal, and the PWM control module includes a second photosensitive transistor UB2 for receiving the second signal.

[0015] By adopting the above technical solution, the anti-sticking submodule can output a higher current when receiving the first signal so that the second light-emitting diode UA2 will emit light to send out the second signal, so that the PWM control module reduces the current of the welding machine output port, thereby facilitating the separation of the welding rod and the workpiece that are stuck. The VRD submodule can control the output current by manually operating the VRD control switch. When the VRD control switch is turned on, the VRD submodule will also output a higher current so that the second light-emitting diode UA2 will emit light to send out the second signal, so that the PWM control module reduces the voltage of the welding machine output port, thereby reducing the damage to the welding machine user when the welding machine output port is accidentally touched.

[0016] Optionally, the anti-adhesion submodule includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first phototransistor UB1, a second electrolytic capacitor E2, a second capacitor C2, a second voltage stabilizing diode Z2, a first transistor Q1, and a second diode D2, wherein the collector of the first phototransistor UB1 is connected to the positive electrode of the power supply, the emitter of the first phototransistor UB1 is connected to the fifth resistor R5 and the sixth resistor R6, the other end of the fifth resistor R5 is grounded, the other end of the sixth resistor R6 is connected to the negative electrode of the second voltage stabilizing diode Z2, the fourth resistor R4, the second electrolytic capacitor E2 and the second capacitor C2 are respectively connected in parallel between the sixth resistor R6 and the second voltage stabilizing diode Z2, the other ends of the second electrolytic capacitor E2 and the second capacitor C2 are both grounded, and the other end of the fourth resistor R4 is connected to the positive electrode of the power supply;

[0017] The anode of the second voltage stabilizing diode Z2 is connected to the seventh resistor R7 and the base of the first transistor Q1, the other end of the seventh resistor R7 is grounded, the emitter of the first transistor Q1 is grounded, the collector of the first transistor Q1 is connected to the eighth resistor R8 and the anode of the second diode D2, the other end of the eighth resistor R8 is connected to the positive electrode of the power supply, the cathode of the second diode D2 is connected to the anode of the second light-emitting diode UA2, and the cathode of the second light-emitting diode UA2 is grounded.

[0018] By adopting the above technical solution, when the first phototransistor UB1 receives the first signal emitted by the first light-emitting diode UA1, it will output a photosensitive current to increase the current in the circuit, and the second electrolytic capacitor E2 and the second capacitor C2 can filter the current, and the second voltage-stabilizing diode Z2 can have a voltage-stabilizing effect. Due to the increase in current, the base current of the first transistor Q1 increases, causing the collector current of the first transistor Q1 to be amplified. After the amplified current passes through the second diode D2 for limiting, the second light-emitting diode UA2 will emit light and send out a second signal, and the seventh resistor R7 can be used as a pull-down resistor of the first transistor Q1.

[0019] Optionally, the anti-sticking submodule further includes a first switching switch K1, which is disposed outside the welding machine and connected between the fourth resistor R4 and the sixth resistor R6.

[0020] By adopting the above technical solution, since the fourth resistor R4 is connected to an external power supply, the external power supply connected to the fourth resistor R4 is used to establish the static operating point of the first transistor Q1. Therefore, when the external power supply connected to the fourth resistor R4 is disconnected, the first transistor Q1 will not be turned on. Therefore, the conduction state of the first transistor Q1 can be controlled by the first switching switch K1, thereby further controlling whether the second light-emitting diode UA2 emits light when the first photosensitive transistor UB1 receives the first signal emitted by the first light-emitting diode UA1.

[0021] Optionally, the VRD submodule includes a ninth resistor R9 and a second switching switch K2, one end of the ninth resistor R9 is connected to the positive electrode of the power supply, the other end of the ninth resistor R9 is connected to the second switching switch K2, and the other end of the second switching switch K2 is connected between the cathode of the second diode D2 and the anode of the second light-emitting diode UA2.

[0022] By adopting the above technical solution, the ninth resistor R9 is connected to an external power supply, and the on and off of the external power supply is controlled by the second switching switch K2. Because the second switching switch K2 is directly connected to the second light-emitting diode UA2, the second switching switch K2 can directly control whether the second light-emitting diode UA2 emits light and sends a second signal.

[0023] Optionally, the circuit also includes an auxiliary module, which includes an auxiliary power supply submodule and a reset submodule, the auxiliary power supply submodule is respectively connected to the port positive pole and the port negative pole of the welder output port, the auxiliary power supply submodule is used to output a third signal when the welder output port changes from a short-circuit state to a non-short-circuit state, and output an auxiliary voltage to the welder output port, the reset submodule is connected to the anti-sticking submodule and the VRD submodule, the reset submodule is used to receive the third signal and respond to the third signal to reset the anti-sticking submodule, and the reset submodule is used to supply power to the VRD submodule.

[0024] By adopting the above technical solution, when the output port of the welding machine is short-circuited, the PWM control module will reduce the current of the output port of the welding machine through the port detection module and the anti-sticking sub-module, so that the welding machine user can separate the adhered welding rod from the workpiece conveniently. When the welding rod is separated from the workpiece, the output port of the welding machine will be changed to a non-short-circuited state. At this time, the auxiliary power supply sub-module will output a third signal and also output an auxiliary voltage to the output port of the welding machine. The reset module can reset the anti-sticking sub-module after receiving the third signal, and the reset module can also serve as an external power supply for the VRD sub-module to power the VRD sub-module.

[0025] Optionally, the reset submodule includes a third phototransistor UB3, a tenth resistor R10 and a third capacitor C3, the collector of the third phototransistor UB3 is connected to the positive electrode of the power supply, the emitter of the third phototransistor UB3 is connected to the VRD submodule through a third diode D3, and the emitter of the third phototransistor UB3 is connected to the positive electrode of the third diode D3, the emitter of the third phototransistor UB3 is also connected to the anti-adhesion submodule through a fourth diode D4, and the emitter of the third phototransistor UB3 is connected to the positive electrode of the fourth diode D4, the tenth resistor R10 and the third capacitor C3 are respectively connected in parallel between the emitter of the third phototransistor UB3 and the positive electrode of the third diode D3, and the other end of the tenth resistor R10 and the other end of the third capacitor C3 are both grounded, and the third phototransistor UB3 is used to receive the third signal.

[0026] By adopting the above technical solution, when the output port of the welding machine is in a non-short-circuit state, the first phototransistor UB1 will not output a photosensitive current, but the auxiliary power supply submodule will output a third signal, so that the third phototransistor UB3 will also output a photosensitive current when receiving the third signal. Since the tenth resistor R10 has a shunt effect, the current finally output by the third phototransistor UB3 will be lower than the current output by the first phototransistor UB1. Therefore, the current output by the third phototransistor UB3 will reset the components of the anti-sticking submodule and will not cause the second light-emitting diode UA2 to emit light. When the second light-emitting diode UA2 does not emit light, the PWM control module will also reset and control the output port of the welding machine to output the welding current normally.

[0027] Optionally, the auxiliary power supply submodule includes a third light emitting diode UA3. When the welding machine output port changes from a short-circuit state to a non-short-circuit state, the third light emitting diode UA3 emits the third signal for the third phototransistor UB3 to receive.

[0028] By adopting the above technical solution, when the welding machine output port changes from a short-circuit state to a non-short-circuit state, the third light-emitting diode UA3 in the auxiliary power supply submodule will light up and send out a third signal, so that the third photosensitive transistor UB3 in the reset submodule receives the third signal to reset the anti-sticking submodule.

[0029] In a second aspect, the present application provides a method for producing an anti-sticking strip in combination with a VRD for a welding machine, comprising the following steps:

[0030] Get the output current of the welding machine output port;

[0031] Determining whether the welding machine output port is short-circuited based on the output current;

[0032] If the welding machine output port is short-circuited, a control signal is output to the PWM control module through the anti-sticking and VRD module, so that the PWM control module reduces the output current until it is lower than a preset current threshold.

[0033] By adopting the above technical solution, the welding rod is connected to the output port of the welding machine. When the welding rod is adhered to the workpiece, the output port of the welding machine will be short-circuited. Therefore, it is possible to detect whether the output port of the welding machine is short-circuited by obtaining the output current of the output port of the welding machine. If a short circuit is detected, a control signal is output to the PWM control module through the anti-sticking and VRD module, so that the PWM control module reduces the output current until it is lower than the preset current threshold. Therefore, the welding rod can be separated from the workpiece conveniently without restarting the welding machine, thereby avoiding damage to circuit components in the welding machine due to frequent restarts of the welding machine.

[0034] In summary, the present application includes at least one of the following beneficial technical effects:

[0035] 1. The welding rod is connected to the output port of the welding machine. When the welding rod is adhered to the workpiece, the output port of the welding machine will be short-circuited. Therefore, the port detection module can be used to detect whether the output port of the welding machine is short-circuited. If a short circuit is detected, a first signal is output to the anti-sticking and VRD module. After receiving the first signal, the anti-sticking and VRD module outputs a second signal to the PWM control module, so that the PWM control module reduces the output current of the output end of the welding machine until it is lower than the preset current threshold. Therefore, the welding rod can be separated from the workpiece without restarting the welding machine, thereby avoiding damage to the circuit components in the welding machine due to frequent restarts of the welding machine.

[0036] 2. The anti-sticking submodule can output a higher current when receiving the first signal, so that the second light-emitting diode UA2 will emit light to send out a second signal, so that the PWM control module reduces the current of the welding machine output port, thereby facilitating the separation of the sticking welding rod and workpiece. The VRD submodule can control the output current by manually operating the VRD control switch. When the VRD control switch is turned on, the VRD submodule will also output a higher current so that the second light-emitting diode UA2 will emit light to send out a second signal, so that the PWM control module reduces the voltage of the welding machine output port, thereby reducing the damage to the welding machine user when accidentally touching the welding machine output port. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a circuit structure diagram of an auxiliary power supply submodule and a port detection module according to one embodiment of the present application.

[0038] Figure 2 It is a circuit structure diagram of a reset submodule and an anti-sticking and VRD module according to one embodiment of the present application.

[0039] Description of reference numerals:

[0040] 1. Port detection module; 2. PWM control module; 31. Anti-sticking submodule; 32. VRD submodule; 41. Auxiliary power supply submodule; 42. Reset submodule. DETAILED DESCRIPTION

[0041] The following is combined with Figure 1 , 2 This application is described in further detail.

[0042] The embodiment of the present application discloses an anti-sticking strip circuit combined with a VRD for a welding machine.

[0043] Reference Figure 1The anti-sticking strip circuit combined with VRD for welding machine includes a port detection module 1, which includes a first diode D1, a first voltage-stabilizing diode Z1, a first electrolytic capacitor E1, a first capacitor C1, a first resistor R1, a second resistor R2, a third resistor R3 and a first light-emitting diode UA1. The positive electrode of the first diode D1 is electrically connected to the positive electrode of the port of the welding machine output port, the negative electrode of the first diode D1 is electrically connected to one end of the first resistor R1, and the other end of the first resistor R1 is electrically connected to one end of the second resistor R2. The first electrolytic capacitor E1, the first capacitor C1 and the first voltage-stabilizing diode Z1 are respectively connected in parallel between the first resistor R1 and the second resistor R2. The other ends of the first electrolytic capacitor E1, the first capacitor C1 and the first voltage-stabilizing diode Z1 are all grounded, wherein the negative electrode of the first electrolytic capacitor E1 and the positive electrode of the first voltage-stabilizing diode Z1 are grounded. The other end of the second resistor R2 is electrically connected to the anode of the third resistor R3 and the first light emitting diode UA1 respectively. The cathodes of the third resistor R3 and the first light emitting diode UA1 are grounded. The first light emitting diode UA1 is used to send a first signal, which is an optical signal.

[0044] Since the welding current outputted from the output port of the welding machine may be alternating current, the welding current can be rectified into direct current through the first diode D1, and then filtered through the first electrolytic capacitor E1 and the first capacitor C1. The first voltage stabilizing diode Z1 can play a role in voltage stabilization, and the first resistor R1 and the second resistor R2 play a role in current limiting. When the welding current is normal, the first light-emitting diode UA1 will not emit light, but when the output port of the welding machine is short-circuited, the current will suddenly increase. At this time, due to the increase in current, the first light-emitting diode UA1 will emit light to send a first signal, and the third resistor R3 can play a role in shunt protection when the current suddenly increases.

[0045] The circuit also includes an auxiliary module, which in turn includes an auxiliary power supply submodule 41, which includes an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a third electrolytic capacitor E3, a fifth diode D5, a fourth capacitor C4, a third light-emitting diode UA3 and a third voltage-stabilizing diode Z3. One end of the eleventh resistor R11 is electrically connected to the positive electrode of the auxiliary power supply in the welding machine. When the output port of the welding machine changes from a short-circuit state to a non-short-circuit state, the positive electrode of the auxiliary power supply will continue to provide a 24V voltage. The other end of the eleventh resistor R11 is electrically connected to the positive electrode of the third electrolytic capacitor E3, the negative electrode of the third electrolytic capacitor E3 is electrically connected to the positive electrode of the fifth diode D5, and the negative electrode of the fifth diode D5 is electrically connected to the positive electrode of the output port of the welding machine through the thirteenth resistor R13.

[0046] A fourth capacitor C4, a twelfth resistor R12 and a third light-emitting diode UA3 are respectively connected in parallel between the negative electrode of the third electrolytic capacitor E3 and the positive electrode of the fifth diode D5, wherein the other end of the fourth capacitor C4 is grounded, the other end of the twelfth resistor R12 is electrically connected to the positive electrode of the auxiliary power supply, the positive electrode of the third light-emitting diode UA3 is electrically connected to the negative electrode of the third electrolytic capacitor E3, the negative electrode of the third light-emitting diode UA3 is electrically connected to the negative electrode of the third voltage-stabilizing diode Z3, and the positive electrode of the third voltage-stabilizing diode Z3 is electrically connected to the negative electrode of the welding machine output port.

[0047] In the auxiliary power supply submodule 41, the eleventh resistor R11, the twelfth resistor R12 and the thirteenth resistor R13 can all play the role of current limiting protection, the third electrolytic capacitor E3 and the fourth capacitor C4 can play the role of filtering, the fifth diode D5 plays the role of unidirectional conduction, and prevents the current of the positive electrode of the port from flowing back to the auxiliary power supply submodule 41, and the third voltage stabilizing diode can play the role of voltage stabilization. When the output port of the welding machine is in a non-short-circuit state, the positive electrode of the auxiliary power supply is normally powered, and at this time the third light-emitting diode UA3 will be turned on and emit light, thereby sending a third signal, which is also an optical signal.

[0048] Reference Figure 2 The circuit also includes a PWM control module 2, the auxiliary module also includes a reset submodule 42, the circuit also includes an anti-sticking and VRD module, and the anti-sticking and VRD module includes an anti-sticking submodule 31, a VRD submodule 32 and a second light-emitting diode UA2. The reset submodule 42, the anti-sticking submodule 31 and the VRD submodule 32 are connected together through a third diode D3 and a fourth diode D4, and the anti-sticking submodule 31 and the VRD submodule 32 are directly electrically connected to the second light-emitting diode UA2.

[0049] Among them, the anti-adhesion sub-module 31 includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first phototransistor UB1, a second electrolytic capacitor E2, a second capacitor C2, a second voltage-stabilizing diode Z2, a first transistor Q1 and a second diode D2, the collector of the first phototransistor UB1 is electrically connected to the positive electrode of the power supply, the emitter of the first phototransistor UB1 is electrically connected to the negative electrode of the second voltage-stabilizing diode Z2 through the sixth resistor R6, and the base of the first phototransistor UB1 is used to receive the first signal emitted by the first light-emitting diode UA1, that is, the first phototransistor UB1 will generate a photosensitive current under the illumination of the first light-emitting diode UA1.

[0050] The fifth resistor R5 is connected in parallel between the emitter of the first light emitting diode UA1 and the sixth resistor R6, and the other end of the fifth resistor R5 is grounded. The fifth resistor R5 can play a role in shunt protection. The second electrolytic capacitor E2 and the second capacitor C2 are respectively connected in parallel between the sixth resistor R6 and the cathode of the second voltage zener diode Z2, and the cathode of the second electrolytic capacitor E2 and the other end of the second capacitor C2 are both grounded. The fourth resistor R4 is connected between the sixth resistor R6 and the cathode of the second voltage zener diode Z2 through the first wiring terminal J1, one end of the fourth resistor R4 is electrically connected to the positive electrode of the 1.5V power supply, and the other end of the fourth resistor R4 is electrically connected to one end of port 1 of the first wiring terminal J1, and the port 2 on the same side as the fourth resistor R4 is electrically connected to the cathode of the second voltage zener diode Z2 through a connecting line, and the other side of the port 1 and the port 2 in the first wiring terminal J1 is connected to the first switching switch K1, and the other sides of the port 1 and the port 2 are respectively electrically connected to the two ends of the first switching switch K1.

[0051] The anode of the second voltage stabilizing diode Z2 is electrically connected to the base of the first triode Q1, the emitter of the first triode Q1 is grounded, and a pull-down resistor seventh resistor R7 is connected in parallel between the emitter and the base of the first triode Q1. The collector of the first triode Q1 is electrically connected to the anode of the 1.5V power supply through the eighth resistor R8, the anode of the second diode D2 is also electrically connected to the collector of the first triode Q1, the cathode of the second diode D2 is electrically connected to the anode of the second light-emitting diode UA2, and the cathode of the second light-emitting diode UA2 is grounded.

[0052] In the anti-adhesion submodule 31, the sixth resistor R6 and the eighth resistor R8 can both be used for voltage division and current limiting, and the fifth resistor R5 can be used for shunt protection. When the first phototransistor UB1 receives the first signal sent by the first light-emitting diode UA1, it will output a photosensitive current to increase the current in the circuit, and the second electrolytic capacitor E2 and the second capacitor C2 can filter the current, and the second voltage-stabilizing diode Z2 can play a voltage-stabilizing effect. Due to the increase in current, the base current of the first transistor Q1 increases, causing the collector current of the first transistor Q1 to be amplified. After the amplified current passes through the second diode D2 for limiting, it will cause the second light-emitting diode UA2 to emit light and send out a second signal, which is also an optical signal. The PWM control module 2 includes a second phototransistor UB2 for receiving the second signal. After the base of the second phototransistor UB2 receives the second signal, it will generate a photosensitive current, thereby driving the PWM control module 2 to adjust the voltage and current of the output port of the welding machine.

[0053] The PWM control module 2 is an existing component commonly used in inverter welding machines. The PWM control module 2 can control the on and off of the inverter circuit switch device so that the output end obtains a series of pulses with equal amplitudes, and uses these pulses to replace the sine wave or the required waveform. That is to say, multiple pulses are generated in half a cycle of the output waveform, so that the equivalent voltage of each pulse is a sine waveform. The obtained output is smooth and has few low-order harmonics. Therefore, the width of each pulse is modulated according to certain rules, which can change the size of the inverter circuit output voltage and the output frequency.

[0054] The reset submodule 42 is electrically connected to the emitter of the first phototransistor UB1 in the anti-adhesion submodule 31 through the fourth diode D4. The fourth diode D4 plays a role of unidirectional conduction to prevent the current in the anti-adhesion submodule 31 from flowing back to the reset submodule 42. The reset submodule 42 includes a third phototransistor UB3, a tenth resistor R10 and a third capacitor C3. The collector of the third phototransistor UB3 is electrically connected to the positive electrode of the 1.5V power supply, and the emitter of the third phototransistor UB3 is electrically connected to the positive electrode of the fourth diode D4. The tenth resistor R10 and the third capacitor C3 are respectively connected in parallel between the emitter of the third phototransistor UB3 and the positive electrode of the fourth diode D4. The tenth resistor R10 and the third capacitor C3 can be used for filtering. The base of the third phototransistor UB3 is used to receive the third signal sent by the third light-emitting diode UA3 in the auxiliary power supply submodule 41 to generate a photosensitive current.

[0055] The VRD submodule 32 includes a ninth resistor R9 and a second switch K2. One end of the ninth resistor R9 is electrically connected to the emitter of the third phototransistor UB3 through a third diode D3. The third diode D3 plays a unidirectional conduction role to prevent the current in the VRD submodule 32 from flowing back to the reset submodule 42. The other end of the ninth resistor R9 is electrically connected to one side of the port 1 of the second wiring terminal J2, and the port 2 on the same side of the second wiring terminal J2 is electrically connected to the positive electrode of the second light-emitting diode UA2 through a connecting line. The other side of the port 1 and the port 2 in the second wiring terminal J2 are connected to the two ends of the second switch K2. The first switch K1 and the second switch K2 are both arranged outside the welding machine, and the user can manually open and close the first switch K1 and the second switch K2.

[0056] Since the first switching switch K1 is connected to a 1.5V external power supply through the fourth resistor R4, and the external power supply connected to the fourth resistor R4 is used to establish a static operating point of the first transistor Q1, when the external power supply connected to the fourth resistor R4 is disconnected, the first transistor Q1 will not be turned on. Therefore, the conduction state of the first transistor Q1 can be controlled by the first switching switch K1, thereby further controlling whether the second light-emitting diode UA2 emits light when the first photosensitive transistor UB1 receives the first signal emitted by the first light-emitting diode UA1.

[0057] The implementation principle of this embodiment is:

[0058] When there is no short circuit at the welding machine output port, the auxiliary power supply submodule 41 normally provides auxiliary power to the welding machine output port, so the third light-emitting diode UA3 will continue to send out the third signal, and the third phototransistor UB3 will continue to receive the third signal and generate a photosensitive current. At this time, even if the first switching switch K1 is in a closed state, the photosensitive current generated by the third phototransistor UB3 is not enough to turn on the first transistor Q1, but when the second switching switch K2 is closed, the photosensitive current generated by the third phototransistor UB3 will directly turn on the second light-emitting diode UA2 through the VRD submodule 32, so that the second light-emitting diode UA2 sends out a second signal, and further the PWM control module 2 reduces the current and voltage of the welding machine output port after receiving the second signal. Therefore, the VRD function will be started when the second switching switch K2 is closed.

[0059] When the welding rod at the output port of the welding machine adheres to the workpiece, a short circuit will occur at the output port of the welding machine and the current will increase. Due to the large short-circuit current, the first light-emitting diode UA1 in the port detection module 1 will be turned on and send out a first signal. At this time, the auxiliary power supply submodule 41 will stop supplying power, and the first phototransistor UB1 will receive the first signal and generate a photosensitive current. If the anti-sticking function is activated at this time, that is, the first switching switch K1 is closed, the current in the anti-sticking submodule 31 can turn on the first transistor Q1, so that the second light-emitting diode UA2 sends out a second signal, and further the PWM control module 2 reduces the current and voltage of the welding machine output port after receiving the second signal. If the anti-sticking function is not turned on when the first phototransistor UB1 receives the first signal and generates a photosensitive current, that is, the first switching switch K1 is in a normally open state, the current in the anti-sticking submodule 31 is not enough to turn on the first transistor Q1, and the second light-emitting diode UA2 will not send out a second signal.

[0060] The present application also discloses a method for making an anti-sticking strip for a welding machine in combination with a VRD, comprising the following steps:

[0061] Get the output current of the welding machine output port;

[0062] Determine whether the welding machine output port is short-circuited based on the output current;

[0063] If the output port of the welding machine is short-circuited, a control signal is output to the PWM control module 2 through the anti-sticking and VRD modules, so that the PWM control module 2 reduces the output current until it is lower than the preset current threshold.

[0064] The implementation principle of this embodiment is:

[0065] The welding rod is connected to the output port of the welding machine. When the welding rod sticks to the workpiece, the output port of the welding machine will be short-circuited. Therefore, whether the output port of the welding machine is short-circuited can be detected by obtaining the output current of the output port of the welding machine. If a short circuit is detected, a control signal is output to the PWM control module 2 through the anti-sticking and VRD modules to make the PWM control module 2 reduce the output current until it is lower than the preset current threshold. Therefore, the welding rod can be separated from the workpiece conveniently without restarting the welding machine, thereby avoiding damage to the circuit components in the welding machine due to frequent restarts of the welding machine.

[0066] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A VRD-combined anti-sticking strip circuit for a welding machine, characterized in that: The circuit comprises: A port detection module (1) is connected to the output port of the welding machine and is used to detect whether the output port of the welding machine is short-circuited, and output a first signal when a short-circuit is detected in the output port of the welding machine; A PWM control module (2), connected to the output port of the welding machine, and used to adjust the output voltage and output current of the output port of the welding machine; an anti-sticking and VRD module, configured to receive the first signal and output a second signal to the PWM control module (2) in response to the first signal; The PWM control module (2) receives the second signal and responds to the second signal to reduce the output current until it is lower than a preset current threshold; The port detection module (1) comprises a first diode D1, a first voltage-stabilizing diode Z1, a first electrolytic capacitor E1, a first capacitor C1, a first resistor R1, a second resistor R2, a third resistor R3 and a first light-emitting diode UA1, wherein the anode of the first diode D1 is connected to the anode of the output port of the welding machine, the cathode of the first diode D1 is connected to one end of the first resistor R1, one end of the first resistor R1 is respectively connected to one end of the first electrolytic capacitor E1, the first capacitor C1, the first voltage-stabilizing diode Z1 and the second resistor R2, the other ends of the first electrolytic capacitor E1, the first capacitor C1 and the first voltage-stabilizing diode Z1 are all grounded, the other end of the second resistor R2 is respectively connected to the anode of the third resistor R3 and the first light-emitting diode UA1, the cathode of the third resistor R3 and the first light-emitting diode UA1 are grounded, and the first light-emitting diode UA1 is used to send the first signal.

2. The anti-sticking strip circuit combined with VRD for welding machine according to claim 1, characterized in that: The anti-adhesion and VRD module comprises an anti-adhesion submodule (31), a VRD submodule (32) and a second light-emitting diode UA2. The VRD submodule (32) comprises a VRD control switch. The anti-adhesion submodule (31) and the VRD submodule (32) are both connected to the positive electrode of the second light-emitting diode UA2. The negative electrode of the second light-emitting diode UA2 is grounded. The anti-adhesion submodule (31) is used to receive the first signal and respond to the first signal to make the second light-emitting diode UA2 emit the second signal. When the VRD control switch is turned on, the VRD submodule (32) will control the second light-emitting diode UA2 to emit the second signal. The PWM control module (2) comprises a second photosensitive transistor UB2 for receiving the second signal.

3. The anti-sticking strip circuit combined with VRD for welding machine according to claim 2, characterized in that: The anti-adhesion submodule (31) comprises a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first phototransistor UB1, a second electrolytic capacitor E2, a second capacitor C2, a second voltage stabilizing diode Z2, a first transistor Q1, and a second diode D2, wherein the collector of the first phototransistor UB1 is connected to the positive electrode of a power supply, the emitter of the first phototransistor UB1 is connected to the fifth resistor R5 and the sixth resistor R6, the other end of the fifth resistor R5 is grounded, the other end of the sixth resistor R6 is connected to the negative electrode of the second voltage stabilizing diode Z2, the fourth resistor R4, the second electrolytic capacitor E2, and the second capacitor C2 are respectively connected in parallel between the sixth resistor R6 and the second voltage stabilizing diode Z2, the other ends of the second electrolytic capacitor E2 and the second capacitor C2 are both grounded, and the other end of the fourth resistor R4 is connected to the positive electrode of the power supply; The anode of the second voltage stabilizing diode Z2 is connected to the seventh resistor R7 and the base of the first transistor Q1, the other end of the seventh resistor R7 is grounded, the emitter of the first transistor Q1 is grounded, the collector of the first transistor Q1 is connected to the eighth resistor R8 and the anode of the second diode D2, the other end of the eighth resistor R8 is connected to the positive electrode of the power supply, the cathode of the second diode D2 is connected to the anode of the second light-emitting diode UA2, and the cathode of the second light-emitting diode UA2 is grounded.

4. The anti-sticking strip circuit combined with VRD for welding machine according to claim 3, characterized in that: The anti-adhesion submodule (31) further comprises a first switch K1, which is arranged outside the welding machine and connected between the fourth resistor R4 and the sixth resistor R6.

5. The anti-sticking strip circuit combined with VRD for welding machine according to claim 2, characterized in that: The VRD submodule (32) comprises a ninth resistor R9 and a second switch K2, wherein one end of the ninth resistor R9 is connected to the positive electrode of the power supply, the other end of the ninth resistor R9 is connected to the second switch K2, and the other end of the second switch K2 is connected between the cathode of the second diode D2 and the anode of the second light-emitting diode UA2.

6. The anti-sticking strip circuit combined with VRD for welding machine according to claim 2, characterized in that: The circuit further comprises an auxiliary module, the auxiliary module comprising an auxiliary power supply submodule (41) and a reset submodule (42), the auxiliary power supply submodule (41) being respectively connected to the positive electrode and the negative electrode of the welder output port, the auxiliary power supply submodule (41) being used to output a third signal when the welder output port changes from a short-circuit state to a non-short-circuit state, and output an auxiliary voltage to the welder output port, the reset submodule (42) being connected to the anti-adhesion submodule (31) and the VRD submodule (32), the reset submodule (42) being used to receive the third signal and to respond to the third signal to reset the anti-adhesion submodule (31), and the reset submodule (42) being used to supply power to the VRD submodule (32).

7. The anti-sticking strip circuit combined with VRD for welding machine according to claim 6, characterized in that: The reset submodule (42) comprises a third phototransistor UB3, a tenth resistor R10 and a third capacitor C3, the collector of the third phototransistor UB3 is connected to the positive electrode of the power supply, the emitter of the third phototransistor UB3 is connected to the VRD submodule (32) via a third diode D3, and the emitter of the third phototransistor UB3 is connected to the positive electrode of the third diode D3, the emitter of the third phototransistor UB3 is also connected to the anti-adhesion submodule (31) via a fourth diode D4, and the emitter of the third phototransistor UB3 is connected to the positive electrode of the fourth diode D4, the tenth resistor R10 and the third capacitor C3 are respectively connected in parallel between the emitter of the third phototransistor UB3 and the positive electrode of the third diode D3, and the other end of the tenth resistor R10 and the other end of the third capacitor C3 are both grounded, and the third phototransistor UB3 is used to receive the third signal.

8. The anti-sticking strip circuit combined with VRD for welding machine according to claim 7, characterized in that: The auxiliary power supply submodule (41) comprises a third light emitting diode UA3. When the welding machine output port changes from a short-circuit state to a non-short-circuit state, the third light emitting diode UA3 emits the third signal received by the third phototransistor UB3.

9. A method for making an anti-sticking strip for a welding machine in combination with VRD, characterized in that: The steps include: Get the output current of the welding machine output port; A port detection module (1) connected to the welding machine output port determines whether the welding machine output port is short-circuited based on the output current; If the welding machine output port is short-circuited, a control signal is output to a PWM control module (2) by outputting a first signal to an anti-sticking and VRD module, so that the PWM control module (2) connected to the welding machine output port reduces the output current until it is lower than a preset current threshold; The port detection module (1) comprises a first diode D1, a first voltage-stabilizing diode Z1, a first electrolytic capacitor E1, a first capacitor C1, a first resistor R1, a second resistor R2, a third resistor R3 and a first light-emitting diode UA1, wherein the anode of the first diode D1 is connected to the anode of the output port of the welding machine, the cathode of the first diode D1 is connected to one end of the first resistor R1, one end of the first resistor R1 is respectively connected to one end of the first electrolytic capacitor E1, the first capacitor C1, the first voltage-stabilizing diode Z1 and the second resistor R2, the other ends of the first electrolytic capacitor E1, the first capacitor C1 and the first voltage-stabilizing diode Z1 are all grounded, the other end of the second resistor R2 is respectively connected to the anode of the third resistor R3 and the first light-emitting diode UA1, the cathode of the third resistor R3 and the first light-emitting diode UA1 are grounded, and the first light-emitting diode UA1 is used to send the first signal.

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