A wire feed state detection circuit and additive manufacturing apparatus

Abstract

This application relates to the field of additive manufacturing and discloses a wire feeding status detection circuit and additive processing equipment. The wire feeding status detection circuit includes an enable control unit, a level comparison unit, a latching reset unit, and a push-pull output unit. The enable control unit is connected to an enable signal interface and the welding wire, and can output the welding wire level status based on an external enable signal from the enable signal interface. The level comparison unit is connected to the enable control unit and can generate a welding wire position status signal based on the welding wire level status. The latching reset unit is connected to the level comparison unit to latch and reset the welding wire position status signal. The push-pull output unit is connected to the latching reset unit and can drive an external control mechanism based on the output signal of the latching reset unit. The additive processing equipment using the wire feeding status detection circuit of this application can promptly detect abnormalities in the welding wire position status during the wire feeding process and handle the status in a timely manner, ensuring the quality of additive processing.

Description

Technical Field

[0001] This application relates to the field of additive manufacturing, specifically to a wire feeding status detection circuit. Furthermore, this application also relates to additive manufacturing equipment. Background Technology

[0002] Additive manufacturing is a technology that uses the gradual accumulation of materials to create solid parts. In a broad sense, additive manufacturing includes 3D printing, cladding, and welding. During additive manufacturing, a molten pool is typically formed on the base material at the additive processing location using lasers and / or electric arcs. The additive material is melted into the molten pool, and after solidification, the corresponding solid structure is formed. It offers advantages such as high design freedom, simple manufacturing processes, and high material utilization, and is widely used in the production of complex-shaped, customized, and small-batch parts.

[0003] Additive manufacturing typically involves a wire feeder delivering the additive welding wire to the additive processing area of ​​the workpiece. The wire is then heated at this area, causing it to fuse and form an additive layer. The wire's feeding position in the molten pool significantly impacts the additive manufacturing process. In laser additive manufacturing, insufficient wire feed can cause the wire tip to break off from the molten pool, easily leading to defects such as wire tip agglomeration and uneven deposition layer height. In arc additive manufacturing, excessive wire feed can cause a decrease in the voltage difference between the wire and the workpiece when the wire contacts the molten pool, affecting the arc's travel. Therefore, it is necessary to monitor the wire's position during the feeding process to promptly detect any abnormalities and ensure optimal additive manufacturing results.

[0004] Existing additive manufacturing equipment typically relies on operators manually observing the wire feeding position and intervening when abnormalities are detected. However, manual observation often fails to detect abnormal wire feeding conditions in a timely manner, making it difficult to prevent processing defects. Some additive manufacturing equipment that uses a molten pool camera to monitor the molten pool can also detect abnormal wire feeding positions from the camera's images. However, even with molten pool camera images, abnormal wire feeding still requires comprehensive manual judgment, and manual intervention is still needed after an abnormality is detected. This again makes it difficult to guarantee timely detection and handling of abnormal conditions. Summary of the Invention

[0005] In order to promptly detect abnormalities in the position of the welding wire during the wire feeding process and to handle the situation in a timely manner to ensure the quality of additive manufacturing, this application provides a wire feeding status detection circuit and additive manufacturing equipment.

[0006] The wire feeding status detection circuit provided in this application adopts the following technical solution: A wire feeding status detection circuit includes an enable control unit, a level comparison unit, a latching reset unit, and a push-pull output unit. The enable control unit is connected to an enable signal interface and a welding wire, and can output the level status of the welding wire according to an external enable signal input from the enable signal interface. The level comparison unit is connected to the enable control unit and can generate a position status signal of the welding wire according to the level status of the welding wire. The latching reset unit is connected to the level comparison unit to latch and reset the position status signal of the welding wire. The push-pull output unit is connected to the latching reset unit and can drive an external control mechanism according to the output signal of the latching reset unit.

[0007] By adopting the above technical solution, an enable control unit connected to an external enable circuit and welding wire can import the electrical level of the welding wire under the control of an external enable signal. This allows for the determination of the welding wire's position based on its electrical level, enabling timely detection of any abnormalities in the welding wire's position during wire feeding. A level comparison unit connected to the enable control unit compares the welding wire's electrical level with a set reference level and determines whether the welding wire's position is abnormal based on the comparison result, ensuring the timeliness and accuracy of the welding wire's position determination. A latching and reset unit connected to the level comparison unit temporarily stores abnormal welding wire position signals, ensuring timely detection and handling of any abnormal welding wire position.

[0008] In one specific implementation, the enable control unit includes an enable relay, which includes a drive coil and a first contact group. The drive coil is connected to the enable signal interface and ground, respectively, and the first contact group is connected to the level comparison unit and the solder wire, respectively.

[0009] By adopting the above technical solution, using drive coils connected to the enable signal interface and ground respectively, a high-level external enable signal can be input when it is necessary to monitor the welding wire position status, driving the enable relay to connect the welding wire to the level comparison unit to determine the welding wire level status; when it is not necessary to monitor the welding wire position status, the input of the external enable signal is stopped, the enable relay is reset to isolate the welding wire from the level comparison unit, preventing welding current or external inductive current from being conducted into the detection circuit, thus protecting the detection circuit during the welding process.

[0010] In one specific implementation, the enable relay further includes a second contact group, which is connected to a high-level point and an enable output interface, respectively.

[0011] By adopting the above technical solution, and using the second contact group connected to the high-level point and the enable output interface respectively, the high level can be transmitted to the enable output interface to form a high-level enable output signal, which notifies the external cooperating device that the detection circuit is ready.

[0012] In one specific implementation, the level comparison unit includes a voltage comparator U2, a sensitivity adjustment module, and a trigger adjustment module. After the enable control unit and the sensitivity adjustment module are connected, they are connected to one of the non-inverting input and the inverting input of the voltage comparator U2. The trigger adjustment module is connected to the other of the non-inverting input and the inverting input of the voltage comparator U2. The output of the voltage comparator U2 is connected to the pull-up resistor R6 and the latch reset unit.

[0013] By adopting the above technical solution, the sensitivity adjustment module connected to the enable control unit can adjust the welding wire level from the enable control unit, thereby adjusting the sensitivity of the welding wire level to the voltage comparator U2. Using the sensitivity adjustment module and the trigger adjustment module, which are respectively connected to the non-inverting and inverting input terminals of the voltage comparator U2, the welding wire level adjusted by the sensitivity adjustment module can be compared with the reference level provided by the trigger adjustment module. Based on the comparison result, the voltage comparator U2 is triggered to accurately reflect the position state of the welding wire.

[0014] In one specific implementation scheme, the level comparison unit further includes a double-pole double-throw switch SW1. The two common terminals of the double-pole double-throw switch SW1 are respectively connected to the non-inverting input terminal and the inverting input terminal of the voltage comparator U2. The first normally open terminal is connected to the sensitivity adjustment module, the second normally open terminal is connected to the trigger adjustment module, the first normally closed terminal is connected to the trigger adjustment module, and the second normally closed terminal is connected to the sensitivity adjustment module.

[0015] By adopting the above technical solution, a double-pole double-throw switch SW1 is used, which connects two common terminals to the non-inverting and inverting input terminals of voltage comparator U2 respectively, two normally open terminals to the sensitivity adjustment module and the trigger adjustment module respectively, and two normally closed terminals to the trigger adjustment module and the sensitivity adjustment module respectively. This allows switching the connection status between the sensitivity adjustment module and the trigger adjustment module and the non-inverting and inverting input terminals of voltage comparator U2, thereby controlling the state of the welding wire level trigger voltage comparator U2. This can be applied to the detection of abnormal position status of welding wire in different additive processing methods.

[0016] In one specific implementation, the sensitivity adjustment module includes a resistor R8, a potentiometer R3, and a resistor R7. The potentiometer R3 is connected between the resistors R8 and R7. The resistor R8 is connected to the drive power supply VCC, and the resistor R7 is connected to ground. The first normally open and second normally closed terminals of the double-pole double-throw switch SW1 are connected between the potentiometer R3 and the resistor R7. The trigger adjustment module includes a potentiometer R4 and a resistor R5. The potentiometer R4 is connected between the drive power supply VCC and the resistor R5. The other end of the resistor R5 is grounded. The first normally closed and second normally open terminals of the double-pole double-throw switch SW1 are connected between the potentiometer R4 and the resistor R5.

[0017] By employing the above technical solution, potentiometer R3 connected between resistors R8 and R7 can adjust the initial level applied to the end of resistor R7, thereby adjusting the influence of the welding wire level on the level at the end of resistor R7 and controlling the sensitivity of the welding wire level trigger voltage comparator U2. Potentiometer R4 connected between the drive power supply VCC and resistor R5 can adjust the level at the connection end of resistor R5, which in turn adjusts the reference level transmitted to the voltage comparator U2, thereby adjusting the trigger level point of the welding wire level.

[0018] In one specific implementation, the latch reset unit includes an RS flip-flop and a reset module. The input of the RS flip-flop is connected to a pull-up resistor R9 and the reset module. The pull-up resistor R9 is connected to the control power supply VDD. The input of the RS flip-flop is connected to the output of the level comparison unit, and the output of the RS flip-flop is connected to the push-pull output unit.

[0019] By adopting the above technical solution, and connecting the input terminal of the RS flip-flop to the pull-up resistor R9 and the output terminal of the level comparison unit, it is possible to ensure that the RS flip-flop can sense and latch the trigger state of the level comparison unit, thereby reliably detecting changes in the welding wire level, i.e., changes in the welding wire position. Using a reset module connected to the input terminal of the RS flip-flop, the RS flip-flop can be reset after the equipment reacts to an abnormal position state of the welding wire, allowing the RS flip-flop to continue detecting changes in the welding wire position.

[0020] In one specific implementation, the reset module includes a diode D11, a resistor R12, and a transistor Q2. The diode D11 and the resistor R12 are connected in series between the reset trigger interface and the base of the transistor Q2. The collector of the transistor Q2 is connected to the input terminal of the RS flip-flop, and the emitter of the transistor Q2 is connected to ground.

[0021] By adopting the above technical solution, the transistor Q2, whose base is connected to the reset trigger interface and whose collector is connected to the input terminal of the RS flip-flop, can trigger the RS flip-flop to reset according to the reset trigger signal from the reset trigger interface, and ensure the isolation between the internal signal of the detection circuit and the reset trigger signal, so as to avoid the internal signal of the circuit from interfering with the external trigger circuit.

[0022] In one specific implementation, the push-pull output unit includes a resistor R15, a transistor Q1, resistors R11 and R10, a Zener diode D13, a P-channel MOSFET Q3, a resistor R17, a transistor Q5, a resistor R19, a resistor R18, a Zener diode D15, an N-channel MOSFET Q4, and a TVS diode D10. Resistor R15 is connected between the latch reset unit and the base of transistor Q1. The emitter of transistor Q1 is grounded, and its collector is connected to the gate of the P-channel MOSFET Q3 through resistor R11. The drain of the P-channel MOSFET Q3 is connected to the drive power supply VCC. Resistor R10 and Zener diode D13 are connected in parallel between the drive power supply VCC and the gate of the P-channel MOSFET Q3. The source of the P-channel MOSFET Q3 is connected to... The source of the N-channel MOSFET Q4 is connected to the ground. The resistor R17 is connected between the latch reset unit and the base of the transistor Q5. The emitter of the transistor Q5 is grounded, and the collector is connected to the gate of the N-channel MOSFET Q4 and connected to the control power supply VDD through the resistor R15. The drain of the N-channel MOSFET Q4 is grounded. The resistor R18 and the Zener diode D15 are connected in parallel between the gate of the N-channel MOSFET Q4 and ground. The TVS diode D10 is connected between the source of the N-channel MOSFET Q4 and ground. The source of the N-channel MOSFET Q4 is connected to the output signal interface.

[0023] By adopting the above technical solution, the P-channel MOSFET Q3, whose gate is connected to transistor Q1 through resistor R11 and whose drain is connected to the driving power supply VCC, can be turned on when the latch reset unit outputs a high level, and output driving current to the external control mechanism; the N-channel MOSFET Q4, whose gate is connected to transistor Q5 and whose drain is grounded, can be turned on when the latch reset unit outputs a low level, and input driving current from the external control mechanism, forming a push-pull drive circuit to trigger and drive the external control mechanism with different input requirements, and to handle the abnormal position state of the welding wire.

[0024] The additive manufacturing equipment provided in this application adopts the wire feeding status detection circuit provided in this application and also has the corresponding advantages of the wire feeding status detection circuit provided in this application.

[0025] In summary, this application includes at least one of the following beneficial technical effects: By setting up an enable drive unit including an enable relay, the enable relay can be activated by an external enable signal after the external conditions are prepared, connecting the welding wire to the level comparison unit to detect the welding wire level, i.e., the welding wire position status. When it is not necessary to detect the welding wire level, the external enable signal is removed, causing the enable relay to reset, thus isolating the welding wire from the detection circuit, avoiding the influence of the current on the welding wire on the detection circuit, and generating an output enable signal consistent with the external enable signal to ensure the coordinated operation of external devices.

[0026] By setting up a level comparison unit including a voltage comparator U2, a sensitivity adjustment module, and a trigger adjustment module, the welding wire level can be compared with a reference level of a set value, and the voltage comparator U2 can be triggered according to the comparison result, ensuring that the trigger state of the voltage comparator U2 changes when the welding wire position state is abnormal; and the trigger sensitivity and trigger voltage of the welding wire level can be adjusted by the sensitivity adjustment module and the trigger adjustment module respectively, ensuring the stability and reliability of the welding wire position state detection.

[0027] By setting up a latching and resetting unit consisting of an RS flip-flop and a reset module, the trigger state of the level comparison unit can be latched by the RS flip-flop, ensuring that the equipment can react to abnormal position status of the welding wire. After the equipment reacts, the RS flip-flop is reset by the reset module so that abnormal position status information of the welding wire can be received and latched again.

[0028] By setting up a push-pull output unit, the position status signal of the welding wire latched in the latching and reset unit can be amplified to form an output push-pull current, which drives the external control mechanism to process the abnormal position of the welding wire, ensuring that the abnormal position status of the welding wire can be corrected in a timely manner and ensuring the quality of additive manufacturing. Attached Figure Description

[0029] Figure 1 This is a schematic block diagram of one embodiment of the wire feeding status detection circuit of this application.

[0030] Figure 2 This is a schematic diagram of the enable control unit circuit in one embodiment of the wire feeding status detection circuit of this application.

[0031] Figure 3 This is a schematic diagram of the level comparison unit circuit in one embodiment of the wire feeding status detection circuit of this application.

[0032] Figure 4 This is a schematic diagram of the latching and reset unit circuit in one embodiment of the wire feeding status detection circuit of this application.

[0033] Figure 5 This is a schematic diagram of the push-pull output unit circuit in one embodiment of the wire feeding status detection circuit of this application.

[0034] Figure 6 This is a schematic diagram of the LED display unit circuit in one embodiment of the wire feeding status detection circuit of this application.

[0035] Figure 7 This is a schematic diagram of the power supply unit circuit in one embodiment of the wire feeding status detection circuit of this application.

[0036] Explanation of reference numerals in the attached diagram: 1. Enable control unit; 11. Enable relay; 111. Drive coil; 112. First contact group; 113. Second contact group; 2. Level comparison unit; 21. Sensitivity adjustment module; 22. Trigger adjustment module; 3. Latch reset unit; 31. RS trigger; 32. Reset module; 4. Push-pull output unit; 5. Welding wire. Detailed Implementation

[0037] The specific embodiments of this application will now be described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0038] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0039] One embodiment of the wire feeding status detection circuit of this application is as follows: Figures 1 to 7 As shown, it includes an enable control unit 1, a level comparison unit 2, a latch reset unit 3, and a push-pull output unit 4. The enable control unit 1 is provided with an enable signal interface EN_INPUT, a wire level interface Wire+, and a comparison unit interface LM1_IN+. The enable signal interface EN_INPUT is connected to an external control mechanism, the wire level interface Wire+ is connected to the wire 5 of an external additive manufacturing device, the workpiece to be processed by additive manufacturing is connected to the common ground of the wire feeding status detection circuit of this application, and the comparison unit interface LM1_IN+ is connected to the input terminal of the level comparison unit 2.

[0040] Before the wire feeding state is entered, an enable signal is input to the enable signal interface EN_INPUT through an external control mechanism. Under the action of the enable signal, the enable control unit 1 can transmit the level state of the welding wire 5 from the welding wire level interface Wire+ to the comparison unit interface LM1_IN+, and transmit it to the level comparison unit 2 through the comparison unit interface LM1_IN+.

[0041] Level comparison unit 2 is connected to the comparison unit interface LM1_IN+, and can compare the level state of welding wire 5 from the comparison unit interface LM1_IN+ with the set reference level to generate a position status signal reflecting the position state of welding wire 5. Since the workpiece undergoing additive manufacturing is connected to ground in the circuit, during the wire feeding process, once welding wire 5 contacts the workpiece, the level on welding wire 5 becomes zero, pulling down the level at the signal input terminal of level comparison unit 2; when welding wire 5 is not in contact with the workpiece, welding wire 5 is in a suspended state, and the signal input terminal of level comparison unit 2 is maintained at the set level under the action of the internal circuit. Level comparison unit 2 can output a position status signal reflecting whether welding wire 5 is in contact with the workpiece when the level state of welding wire 5 changes from suspended to zero, or from zero to suspended.

[0042] The latching reset unit 3 is connected to the level comparison unit 2. It can receive the position status signal from the level comparison unit 2 and latch the position status signal into the latching reset unit 3, ensuring that the external device has sufficient time to react to changes in the position status of the welding wire 5. The latching reset unit 3 can also receive an external reset signal and clear the stored position status signal under the action of the reset signal, so that the latching reset unit 3 can re-receive and latch the position status signal from the level comparison unit 2, restoring the detection function of the welding wire 5's level status.

[0043] The push-pull output unit 4 is connected to the latch reset unit 3. It can amplify the position status signal latched by the latch reset unit 3 to generate a drive signal that can drive the external control mechanism to respond to the position status change of the welding wire 5. The external control mechanism can adjust the working state of the additive manufacturing equipment, such as adjusting the wire feeder to change the wire feeding rhythm, correct the abnormal position status of the welding wire 5, and issue a reset signal after the abnormal position status of the welding wire 5 is cleared, so that the latch reset unit 3 is reset.

[0044] In some embodiments of the wire feeding status detection circuit of this application, such as Figure 2 As shown, the enable control unit 1 is implemented based on the enable relay 11. The enable relay 11 is provided with a drive coil 111 and a first contact group 112. One end of the drive coil 111 is connected to the enable signal interface EN_INPUT through a diode D5, and the other end is connected to ground. A freewheeling diode D4 is connected in parallel across the two ends of the drive coil 111 to suppress the reverse electromotive force generated by the drive coil 111.

[0045] The moving contact of the first contact group 112 is connected to the comparison unit interface LM1_IN+, and is also connected to the level comparison unit 2 through the comparison unit interface LM1_IN+; the normally open stationary contact is connected to the welding wire level interface Wire+ through the self-resetting fuse F4, and is also connected to the welding wire 5 through the welding wire level interface Wire+.

[0046] When an external high-level enable signal is transmitted to the enable signal interface EN_INPUT, current flows through the drive coil 111, driving the enable relay 11 to operate. The moving contact of the first contact group 112 contacts the normally open stationary contact, connecting the welding wire 5 to the level comparison unit 2 to detect the level state of the welding wire 5. When the external enable signal is removed, the enable relay 11 resets, and the moving contact of the first contact group 112 separates from the normally open stationary contact, preventing the welding current on the welding wire 5 or the external inductive current from being conducted into the detection circuit, thus protecting the detection circuit.

[0047] In a preferred embodiment of the wire feeding status detection circuit of this application, such as Figure 2 As shown, the enable relay 11 is also provided with a second contact group 113. The moving contact of the second contact group 113 is connected to a high-level point connected to the positive terminal of the power supply, and the normally open stationary contact is connected to the enable output interface EN_OUTPUT through a self-resetting fuse F3. After the enable relay 11 is activated, it can output an enable output signal to notify the cooperating equipment, such as additive welding machines, robots and other additive control equipment, that the detection circuit is ready.

[0048] In some embodiments of the wire feeding status detection circuit of this application, such as Figure 3 As shown, the level comparison unit 2 includes a voltage comparator U2, a sensitivity adjustment module 21, and a trigger adjustment module 22. The two input terminals of the voltage comparator U2 are connected to the sensitivity adjustment module 21 and the trigger adjustment module 22, respectively. Specifically, the sensitivity adjustment module 21 can be connected to the non-inverting input terminal of the voltage comparator U2, and the trigger adjustment module 22 can be connected to the inverting input terminal of the voltage comparator U2; alternatively, the sensitivity adjustment module 21 can be connected to the inverting input terminal of the voltage comparator U2, and the trigger adjustment module 22 can be connected to the non-inverting input terminal of the voltage comparator U2.

[0049] Sensitivity adjustment module 21 is connected to the comparator unit interface LM1_IN+, and also to the enable control unit 1 via the comparator unit interface LM1_IN+, receiving the voltage level of the welding wire 5 output by the enable control unit 1. A TVS diode D12 and a capacitor C6 are connected between the comparator unit interface LM1_IN+ and ground to absorb spike noise in the voltage level of the welding wire 5. After adjusting the voltage level of the welding wire 5, sensitivity adjustment module 21 transmits the adjusted voltage level signal to voltage comparator U2, which is used to adjust the sensitivity of voltage comparator U2 triggered by the voltage level signal of the welding wire 5.

[0050] The trigger adjustment module 22 can generate a reference level of a set value using the drive power supply VCC. The voltage comparator U2 can compare the level status signal of the welding wire 5 with the reference level. When the level status of the welding wire 5 changes, the output level jumps, forming a position status signal that reflects the position status of the welding wire 5.

[0051] The output of voltage comparator U2 is connected to the control power supply VDD via pull-up resistor R6. The control power supply VDD is typically a +5V supply, which can generate a default high level at the output of voltage comparator U2 through pull-up resistor R6. The output of voltage comparator U2 is connected to latch-reset unit 3, which sends the position status signal output by voltage comparator U2 to latch-reset unit 3.

[0052] In a preferred embodiment of the wire feeding status detection circuit of this application, such as Figure 3 As shown, a double-pole double-throw switch SW1 is also provided in the level comparison unit 2. The two common terminals of the double-pole double-throw switch SW1 are connected to the non-inverting input terminal and the inverting input terminal of the voltage comparator U2, respectively. The first normally open terminal is connected to the sensitivity adjustment module 21, the second normally open terminal is connected to the trigger adjustment module 22, the first normally closed terminal is connected to the trigger adjustment module 22, and the second normally closed terminal is connected to the sensitivity adjustment module 21.

[0053] When the common terminal of the double-pole double-throw switch SW1 is connected to the normally closed terminal, the sensitivity adjustment module 21 is connected to the inverting input terminal of the voltage comparator U2, and the trigger adjustment module 22 is connected to the non-inverting input terminal of the voltage comparator U2. At this time, when the welding wire 5 is in contact with the workpiece, the inverting input terminal of the voltage comparator U2 receives a low level, and the non-inverting input terminal receives a reference level. The level at the inverting input terminal is lower than the reference level at the non-inverting input terminal, and the voltage comparator U2 outputs a high-level signal. When the welding wire 5 is not in contact with the workpiece, the inverting input terminal of the voltage comparator U2 receives a high level, which is higher than the reference level at the non-inverting input terminal, and the voltage comparator U2 outputs a low-level signal. This allows the wire feeding status detection circuit of this application to be used in laser additive manufacturing mode: during normal additive manufacturing, the end of the welding wire 5 is always located in the molten pool on the workpiece, ensuring that the welding wire 5 is continuously melted and replenished into the molten pool, and the voltage comparator U2 outputs a high-level signal reflecting the normal position status of the welding wire 5; once the end of the welding wire 5 is disconnected from the molten pool and cannot be replenished into the molten pool, the voltage comparator U2 outputs a low-level signal, indicating that the position status of the welding wire 5 is abnormal and intervention is required.

[0054] When the common terminal of the double-pole double-throw switch SW1 is connected to the normally open terminal, the sensitivity adjustment module 21 is connected to the non-inverting input terminal of the voltage comparator U2, and the trigger adjustment module 22 is connected to the inverting input terminal of the voltage comparator U2. At this time, when the welding wire 5 is not in contact with the workpiece, the non-inverting input terminal of the voltage comparator U2 receives a high level, and the inverting input terminal receives a reference level. The level at the non-inverting input terminal is higher than the reference level at the inverting input terminal, and the voltage comparator U2 outputs a high-level signal. When the welding wire 5 is in contact with the workpiece, the non-inverting input terminal of the voltage comparator U2 receives a low level, lower than the reference level at the inverting input terminal, and the voltage comparator U2 outputs a low-level signal. This allows the wire feeding status detection circuit of this application to be used in the arc additive manufacturing mode: during normal additive manufacturing, the end of the welding wire 5 is never in contact with the workpiece. An arc is generated between the end of the welding wire 5 and the workpiece due to the potential difference, melting the welding wire 5 into the molten pool on the workpiece. The voltage comparator U2 outputs a high-level signal reflecting that the position status of the welding wire 5 is normal. Once the end of the welding wire 5 contacts the workpiece, the potential difference between the two disappears, affecting the generation of the arc. The voltage comparator U2 then outputs a low-level signal, indicating that the position status of the welding wire 5 is abnormal and intervention is required.

[0055] In this way, by setting the double-pole double-throw switch SW1, the wire feeding status detection circuit of this application can be used in two different additive processing equipment, laser additive processing and electric arc additive processing, to detect abnormal wire feeding status, thereby improving the applicability of the wire feeding status detection circuit of this application.

[0056] One specific implementation of the wire feeding status detection circuit in this application is as follows: Figure 3As shown, the sensitivity adjustment module 21 includes a resistor R8, a potentiometer R3, and a resistor R7. One end of resistor R8 is connected to the drive power supply VCC, which typically uses a +24V power supply. Potentiometer R3 is connected between resistors R8 and R7, and the other end of resistor R7 is connected to ground. The first normally open and second normally closed terminals of the double-pole double-throw switch SW1 are connected to the connection point between potentiometer R3 and resistor R7. Adjusting potentiometer R3 adjusts the voltage drop across resistor R7, which is the base level of the comparator interface LM1_IN+. This adjusts the influence of the welding wire 5's voltage level on the comparator interface LM1_IN+, thus regulating the sensitivity of the welding wire 5 voltage level change trigger voltage comparator U2.

[0057] The trigger adjustment module 22 includes a potentiometer R4 and a resistor R5. Potentiometer R3 is connected between the drive power supply VCC and resistor R5. The other end of resistor R5 is grounded. The first normally closed terminal and the second normally open terminal of the double-pole double-throw switch SW1 are connected to the connection point between potentiometer R4 and resistor R5. Adjusting potentiometer R3 adjusts the voltage drop across resistor R5, which in turn adjusts the reference voltage transmitted to the input of voltage comparator U2.

[0058] In some embodiments of the wire feeding status detection circuit of this application, such as Figure 4 As shown, the latch reset unit 3 includes an RS flip-flop 31 and a reset module 32. The reset module 32 is formed by two digital logic gate chips U3 and U4 connected in a cross-connection. The A input terminal of digital logic gate chip U3 serves as the input terminal of RS flip-flop 31, the B input terminal is connected to the Y output terminal of digital logic gate chip U4, which serves as the output terminal of RS flip-flop 31, the Y output terminal is connected to the A input terminal of digital logic gate chip U4, which serves as the Q output terminal of RS flip-flop 31, and the B input terminal of digital logic gate chip U4 serves as the input terminal of RS flip-flop 31.

[0059] The input of RS flip-flop 31 is connected to the output of level comparison unit 2. The input is also connected to pull-up resistor R9 and the output of reset module 32. The other end of pull-up resistor R9 is connected to control power supply VDD, ensuring that the input of RS flip-flop 31 is at a high level by default. Thus, in the default state, when the input of RS flip-flop 31 is low, the Q output is high and the output of the other terminal is low; conversely, when the input of RS flip-flop 31 is high, the output levels of the Q and other terminals remain unchanged, effectively latching the low-level output of level comparison unit 2 after it is triggered.

[0060] When the RS flip-flop 31 is in latched state, a level reset signal is input to the input terminal of the RS flip-flop 31 through the reset module 32. The Q output terminal of the RS flip-flop 31 outputs a low level, and the output terminal outputs a high level, clearing the latch of the low level state output after the level comparison unit 2 is triggered, so that the RS flip-flop 31 can resume its ability to record and latch the low level signal output by the level comparison unit 2.

[0061] The output of RS flip-flop 31 is connected to push-pull output unit 4, which can transmit the low-level signal output by RS flip-flop 31 to push-pull output unit 4. The push-pull output unit 4 amplifies the signal and uses it as a drive signal to respond to abnormal wire feeding status of welding wire 5.

[0062] In a preferred embodiment of the wire feeding status detection circuit of this application, such as Figure 4 As shown, the reset module 32 includes a diode D11, a resistor R12, and a transistor Q2. The anode of diode D11 is connected to the reset trigger interface RST_INPUT, and is connected to an external control mechanism through the reset trigger interface RST_INPUT. The cathode is connected to one end of resistor R12, and the other end of resistor R12 is connected to the base of transistor Q2. The collector of transistor Q2 is connected to the input terminal of RS flip-flop 31, which is the B input terminal of digital logic gate chip U4. The emitter of transistor Q2 is connected to ground.

[0063] When the wire feeding status of welding wire 5 is abnormal, after RS ​​flip-flop 31 latches the abnormal position status signal of welding wire 5, push-pull output unit 4 outputs a drive signal to control the external control mechanism to handle the abnormal wire feeding status. After the external control mechanism completes the processing, it sends a high-level reset signal to the reset trigger interface RST_INPUT. After being filtered by diode D11 and current-limited by resistor R12, the high-level reset signal drives transistor Q2 to conduct, and the collector of transistor Q2 outputs a low level, which is sent to the input of RS flip-flop 31, causing RS flip-flop 31 to be reset to 0.

[0064] In some embodiments of the wire feeding status detection circuit of this application, such as Figure 5As shown, the push-pull output unit 4 includes a single-pole double-throw switch SW2, resistor R15, transistor Q1, resistors R11 and R10, Zener diode D13, P-channel MOSFET Q3, resistor R17, transistor Q5, resistor R19, resistor R18, Zener diode D15, N-channel MOSFET Q4, and TVS diode D10. The two stationary terminals of the single-pole double-throw switch SW2 are connected to the inverting and retracting output terminals of the latching reset unit 3, specifically to the Q output terminal and the output terminal of the RS flip-flop 31, respectively. The moving terminal is connected to one end of resistors R15 and R17. The other end of resistor R15 is connected to the base of transistor Q1, the emitter of transistor Q1 is grounded, and the collector is connected to the gate of P-channel MOSFET Q3 through resistor R11. The drain of P-channel MOSFET Q3 is connected to the drive power supply VCC. Resistor R10 and Zener diode D13 are connected in parallel between the drive power supply VCC and the gate of P-channel MOSFET Q3. The source of P-channel MOSFET Q3 is connected to the source of N-channel MOSFET Q4.

[0065] The other end of resistor R17 is connected to the base of transistor Q5. The emitter of transistor Q5 is grounded, and the collector is connected to the gate of N-channel MOSFET Q4, and then connected to the control power supply VDD through resistor R15. The drain of N-channel MOSFET Q4 is grounded. Resistor R18 and Zener diode D15 are connected in parallel between the gate of N-channel MOSFET Q4 and ground. TVS diode D10 is connected between the source of N-channel MOSFET Q4 and ground. The source of N-channel MOSFET Q4 is connected to the output signal interface WS_OUTPUT through resettable fuse F2, enabling connection to an external control mechanism via the output signal interface WS_OUTPUT. Diode D14 is connected in reverse between the output signal interface WS_OUTPUT and ground.

[0066] When the wire feeding status of welding wire 5 is abnormal, voltage comparator U2 outputs a low-level signal, which is latched by RS flip-flop 31 and then outputs a high level from the Q output terminal of RS flip-flop 31, and outputs a low level from the output terminal.

[0067] When the moving terminal of switch SW2 is connected to the stationary terminal connected to the Q output of RS flip-flop 31, the high-level output signal drives transistors Q1 and Q5 to conduct through resistors R15 and R17, respectively. The collector of transistor Q1 outputs a low level, turning on P-channel MOSFET Q3; the collector of transistor Q5 outputs a low level, turning off N-channel MOSFET Q4. The output signal interface WS_OUTPUT outputs sink current to the outside to drive the external control mechanism of the NPN input interface.

[0068] When the moving terminal of switch SW2 is connected to the stationary terminal connected to the output terminal of RS flip-flop 31, the low-level output signal causes both transistors Q1 and Q5 to be cut off. The collector of transistor Q1 outputs a high level, and P-channel MOSFET Q3 is cut off; the collector of transistor Q5 outputs a high level, and N-channel MOSFET Q4 is turned on. The output signal interface WS_OUTPUT receives a pull-up current from the outside to drive the external control mechanism of the PNP input interface.

[0069] In this way, the push-pull output unit 4 can simultaneously adapt to external control mechanisms with both external NPN and PNP input interfaces, improving the applicability of the wire feeding status detection circuit of this application. The resettable fuse F2 is limited to tripping when a continuous current of 200mA or a momentary current of 500mA is applied, preventing damage to the push-pull output unit 4 and / or the external control mechanism due to overcurrent. After tripping, the resettable fuse F2 automatically resets as the temperature decreases, eliminating the need for manual fuse replacement.

[0070] Of course, push-pull output unit 4 can also use other existing push-pull amplifier circuits such as totem poles, as long as push-pull output can be achieved.

[0071] The wire feeding status detection circuit of this application can also be configured as follows: Figure 6 The LED display unit shown includes LEDs D2, D7, and D8 that emit green light, and LEDs D1 and D3 that emit red light. LED D2 is connected to the drive power supply VCC via resistor R2 to indicate the power supply status of VCC; LED D7 is connected to the enable signal interface EN_INPUT via resistor R14 to indicate an external enable signal; LED D8 is connected to the reset trigger interface RST_INPUT via resistor R16 to indicate a reset signal from an external control mechanism; LED D1 is connected to the enable output interface EN_OUTPUT via resistor R1 to indicate an enable output signal from the control unit 1; and LED D3 is connected to the output signal interface WS_OUTPUT via resistor R13 to indicate the drive signal output by the push-pull output unit 4. This allows the operating status of the wire feeding state detection circuit of this application to be determined by the illumination status of multiple LEDs.

[0072] The wire feeding status detection circuit of this application can also be configured with, for example, Figure 7 The dedicated power supply unit shown receives an externally supplied +24V power supply. This power is limited by a resettable fuse F1, high-amplitude interference is removed by a TVS diode D9, and the voltage is regulated by a field-effect transistor Q6, forming a +24V drive power supply VCC. The drive power supply VCC is then stepped down and regulated by a three-terminal voltage regulator chip U1 to form a +5V control power supply VDD.

[0073] One embodiment of the additive manufacturing equipment of this application uses the wire feeding status detection circuit of any embodiment of this application to detect the wire feeding status of the welding wire 5, and can control the wire feeding status of the welding wire 5 according to the monitoring results to ensure the quality of additive manufacturing.

[0074] In the description of this application, the references to terms such as "an embodiment," "specific embodiment," and "preferred embodiment" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this application, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0075] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A wire feeding status detection circuit, characterized in that, The device includes an enable control unit (1), a level comparison unit (2), a latch reset unit (3), and a push-pull output unit (4). The enable control unit (1) is connected to the enable signal interface and the welding wire (5) and can output the level state of the welding wire (5) according to the external enable signal input by the signal interface. The level comparison unit (2) is connected to the enable control unit (1) and can generate the position state signal of the welding wire (5) according to the level state of the welding wire (5). The latch reset unit (3) is connected to the level comparison unit (2) and can latch and reset the position state signal of the welding wire (5). The push-pull output unit (4) is connected to the latch reset unit (3) and can drive an external control mechanism according to the output signal of the latch reset unit (3).

2. The wire feeding status detection circuit according to claim 1, characterized in that, The enable control unit (1) includes an enable relay (11), which includes a drive coil (111) and a first contact group (112). The drive coil (111) is connected to the enable signal interface and ground respectively, and the first contact group (112) is connected to the level comparison unit (2) and the welding wire (5) respectively.

3. The wire feeding status detection circuit according to claim 2, characterized in that, The enable relay (11) also includes a second contact group (113), which is connected to the high-level point and the enable output interface respectively.

4. The wire feeding status detection circuit according to claim 1, characterized in that, The level comparison unit (2) includes a voltage comparator U2, a sensitivity adjustment module (21), and a trigger adjustment module (22). After the enable control unit (1) and the sensitivity adjustment module (21) are connected, they are connected to one of the non-inverting input terminal and the inverting input terminal of the voltage comparator U2. The trigger adjustment module (22) is connected to the other of the non-inverting input terminal and the inverting input terminal of the voltage comparator U2. The output terminal of the voltage comparator U2 is connected to the pull-up resistor R6 and the latch reset unit (3).

5. The wire feeding status detection circuit according to claim 4, characterized in that, The level comparison unit (2) further includes a double-pole double-throw switch SW1. The two common terminals of the double-pole double-throw switch SW1 are respectively connected to the non-inverting input terminal and the inverting input terminal of the voltage comparator U2. The first normally open terminal is connected to the sensitivity adjustment module (21), the second normally open terminal is connected to the trigger adjustment module (22), the first normally closed terminal is connected to the trigger adjustment module (22), and the second normally closed terminal is connected to the sensitivity adjustment module (21).

6. The wire feeding status detection circuit according to claim 5, characterized in that, The sensitivity adjustment module (21) includes a resistor R8, a potentiometer R3, and a resistor R7. The potentiometer R3 is connected between the resistor R8 and the resistor R7. The resistor R8 is connected to the driving power supply VCC, and the resistor R7 is connected to ground. The first normally open terminal and the second normally closed terminal of the double-pole double-throw switch SW1 are connected between the potentiometer R3 and the resistor R7. The trigger adjustment module (22) includes a potentiometer R4 and a resistor R5. The potentiometer R3 is connected between the driving power supply VCC and the resistor R5. The other end of the resistor R5 is grounded. The first normally closed terminal and the second normally open terminal of the double-pole double-throw switch SW1 are connected between the potentiometer R4 and the resistor R5.

7. The wire feeding status detection circuit according to claim 1, characterized in that, The latch reset unit (3) includes an RS flip-flop (31) and a reset module (32). The input terminal of the RS flip-flop (31) is connected to the pull-up resistor R9 and the reset module (32). The pull-up resistor R9 is connected to the control power supply VDD. The input terminal of the RS flip-flop (31) is connected to the output terminal of the level comparison unit (2). The output terminal of the RS flip-flop (31) is connected to the push-pull output unit (4).

8. The wire feeding status detection circuit according to claim 7, characterized in that, The reset module (32) includes a diode D11, a resistor R12 and a transistor Q2. The diode D11 and the resistor R12 are connected in series between the reset trigger interface and the base of the transistor Q2. The collector of the transistor Q2 is connected to the input terminal of the RS flip-flop (31), and the emitter of the transistor Q2 is connected to ground.

9. The wire feeding status detection circuit according to claim 1, characterized in that, The push-pull output unit (4) includes a resistor R15, a transistor Q1, resistors R11 and R10, a Zener diode D13, a P-channel MOSFET Q3, a resistor R17, a transistor Q5, a resistor R19, a resistor R18, a Zener diode D15, an N-channel MOSFET Q4, and a TVS diode D10. Resistor R15 is connected between the latch reset unit (3) and the base of transistor Q1. The emitter of transistor Q1 is grounded, and its collector is connected to the gate of P-channel MOSFET Q3 through resistor R11. The drain of P-channel MOSFET Q3 is connected to the drive power supply VCC. Resistor R10 and Zener diode D13 are connected in parallel between the drive power supply VCC and the gate of P-channel MOSFET Q3. The source of P-channel MOSFET Q3 is connected to... The source of the N-channel MOSFET Q4 is connected to the ground. The resistor R17 is connected between the latch reset unit (3) and the base of the transistor Q5. The emitter of the transistor Q5 is grounded, and the collector is connected to the gate of the N-channel MOSFET Q4 and connected to the control power supply VDD through the resistor R15. The drain of the N-channel MOSFET Q4 is grounded. The resistor R18 and the Zener diode D15 are connected in parallel between the gate of the N-channel MOSFET Q4 and ground. The TVS diode D10 is connected between the source of the N-channel MOSFET Q4 and ground. The source of the N-channel MOSFET Q4 is connected to the output signal interface.

10. An additive manufacturing apparatus, characterized in that, Includes the wire feeding status detection circuit according to any one of claims 1-9.

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