Electron beam welding machine electron beam flow multi-mode control system and method thereof

Abstract

This invention discloses a multi-mode control system and method for an electron beam welding machine. The system includes: a central control unit, an electron gun working circuit, a transmitter, and a regulating tube. The method includes the following steps: acquiring the working mode and setting parameters; acquiring sampling signals in the electron gun working circuit according to different working modes, shaping and amplifying the acquired sampling signals as feedback quantities, and adjusting the setting parameters and feedback quantities to obtain the grid bias voltage control signal u. k According to u k To provide the gate bias voltage U to the electron gun operating circuit g ; Obtain the discharge status of the electron gun's operating circuit, once the discharge signal u δ When the signal is active high, the adjustment operation stops and the central control device is notified. This invention is used to realize multi-mode control of electron beam welding machines and expand the processing functions of electron beam welding machines.

Description

A multi-mode control system and method for electron beam welding machine. Technical Field

[0001] This invention relates to the field of e-book processing technology, and more specifically to an electron beam welding machine electron beam current multimode control system and method. Background Technology

[0002] Electron beam current control in electron beam welding machines generally aims at stability. The sampling signal of the electron beam current amplitude is used as a feedback signal to perform closed-loop regulation of the electron beam current. The electron beam current is controlled to follow the given command by adjusting the grid bias voltage or the cathode heating power.

[0003] With the development of production technology, higher requirements have been placed on the performance and functions of electron beam welding machines. However, conventional electron beam current regulators are located at the low-voltage end, have a single control mode, and are difficult to meet the new requirements in terms of adjustment speed and accuracy.

[0004] Therefore, how to provide a high-performance electron beam control system and method with flexible control modes is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides an electron beam welding machine multimode control system and method for realizing multimode control of electron beam welding machine and expanding the processing function of electron beam welding machine.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An electron beam welding machine electron beam current multimode control system includes: a main control device, a central control unit, an electron gun working circuit, a transmitter, and a regulating tube;

[0008] The master control device is connected to the central control unit and is used to send the working mode and setting parameters to the central control unit, and to receive the electron gun operating parameters collected by the central control unit.

[0009] The central control unit is also connected to the transmitter, the regulating tube, and the electron gun operating circuit, respectively. It is used to collect electron gun operating parameters through the transmitter, and select the operating parameters as feedback quantities according to different operating modes. The corresponding set parameters are then adjusted and calculated with the feedback quantities to obtain the grid bias voltage control signal u. k And send it to the regulating tube, and also use it to obtain a discharge fault signal through the transmitter. Once the discharge signal u δ Active high level, stop adjustment operation;

[0010] The transmitter is also connected to the electron gun working circuit to acquire the sampling signal in the electron gun working circuit, and to shape and amplify the acquired sampling signal before sending it to the central control unit.

[0011] The regulating tube is also connected to the electron gun operating circuit, and the output terminal of the regulating tube is connected to a common terminal for controlling the gate bias voltage signal u according to the gate bias voltage. k To adjust the gate bias voltage U of the electron gun operating circuit g This allows for adjustment of the electron beam current;

[0012] The operating modes include gate bias voltage closed-loop regulation mode, microbeam operating mode, conventional beam operating mode, and pulse beam operating mode;

[0013] In the gate bias voltage closed-loop regulation mode, the set parameter is the cutoff gate bias voltage amplitude. The feedback quantity is the gate bias voltage signal u. G After the gate bias voltage is adjusted by the central control unit, a gate bias voltage control signal u is output. k And recorded as the cutoff gate bias voltage control signal u k0 ;

[0014] In the microbeam operating mode, the set parameters include the microbeam amplitude. The feedback quantity is the microbeam signal u' B Through the micro-beam adjustment calculation of the central control unit, the calculation result is compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u. k ;

[0015] In the conventional beam operating mode, the set parameters include the electron beam current amplitude. The feedback quantity is the electron beam signal u. B Through the electron beam current adjustment calculation of the central control unit, the calculation result is compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u. k ;

[0016] In the pulse beam operating mode, the setting parameters also include a large beam current amplitude. Small beam amplitude The duration τ of the large beam within one pulse cycle H The duration τ of a small beam within a pulse period L ;

[0017] In τ H Inside, with a large beam amplitude The set parameters are the electron beam signal u.B The feedback quantity is calculated by the large beam current adjustment of the central control unit, and the calculation result is compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u. k ;

[0018] In τ L Inside, with a small beam amplitude The set parameters are the electron beam signal u. B The feedback quantity is calculated by the small beam current adjustment of the central control unit, and the calculation result is compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u. k .

[0019] Preferably, the electron gun operating circuit includes a bias branch, which includes connected resistors R1 and R2. One end of R1 and R2 is connected to the transmitter as the output terminal of the bias branch. The other end of R1 is connected to the grid bias of the electron gun, and the other end of R2 is connected to the output terminal of the regulating tube and the cathode of the electron gun, respectively.

[0020] Preferably, the electron gun operating circuit further includes a beam branch, a high-voltage branch, and an accelerating power supply;

[0021] The beam branch includes resistors R3 and R4 and a Zener diode Z1. One end of each of R3 and R4 is connected to the K-terminal of Z1, the other end of R3 is connected to the electron gun cathode, and the other end of R4 is connected to the A-terminal of Z1. The K-terminal of Z1 serves as the output terminal for the electron beam sampling signal, and the A-terminal of Z1 serves as the output terminal for the micro-beam sampling signal. The K-terminal and A-terminal of Z1 are respectively connected to the transmitter. Furthermore, the resistance value of resistor R4 is much greater than that of resistor R3.

[0022] The high-voltage branch includes connected R5 and R6. One end of R5 and R6 is connected to the transmitter as the output terminal of the high-voltage branch. The other end of R5 is connected to the A pole of Z1 and the negative output terminal of the accelerating power supply, respectively. The other end of R6 is connected to the positive output terminal of the accelerating power supply.

[0023] The positive output terminal of the acceleration power supply is grounded.

[0024] Preferably, the transmitter includes a bias detection circuit, which includes an operational amplifier A75, a resistor R715, a resistor R716, a resistor R717, and a capacitor C76.

[0025] The output of the bias branch is connected to the inverting input of A75 via R715. The two ends of R716 are connected to the inverting input and the output of A75, respectively. The output of A75 is connected to one end of R717. The other end of R717 is connected to one end of C76 and then serves as the output of the bias detection circuit, which is connected to the central control unit. The non-inverting input of A75 and the other end of C76 are connected to a common terminal.

[0026] Preferably, the transmitter includes a microbeam detection circuit, a high-voltage detection circuit, and a discharge detection circuit;

[0027] The microbeam detection circuit includes operational amplifier A73, resistors R709 to R711, and capacitor C74. In the beam branch, the A terminal of Z1 is connected to the inverting output terminal of A73 via R709. The two ends of R710 are connected to the inverting input terminal and the output terminal of A73, respectively. The output terminal of A73 is connected to one end of R711. The other end of R711 is connected to one end of C74 and then serves as the output terminal of the microbeam detection circuit, which is connected to the central control unit. The non-inverting input terminal of A73 is connected to the other end of C74 and then connected to the common terminal.

[0028] The high-voltage detection circuit includes operational amplifier A72, resistors R704 to R708, and capacitor C73. The output terminal of the high-voltage branch is connected to the non-inverting input terminal of A72 via R705. The A terminal of Z1 in the beam branch is also connected to the inverting input terminal of A72 via R704. The two ends of R707 are respectively connected to the inverting input terminal and the output terminal of A72. The output terminal of A72 is connected to one end of R708. The other end of R708 is connected to one end of C73 and then serves as the output terminal of the high-voltage detection circuit, which is connected to the central control unit. The other end of C73 is connected to the common terminal. The non-inverting input terminal of A72 is also connected to the common terminal via R706.

[0029] The discharge detection circuit includes a 555 timer chip A71, resistors R701 to R703, capacitors C71 and C72, forming a monostable circuit. The output of A72 is connected to pin 2 of A71 via C71 and R702. R701 is connected to pins 2 and 8 of A71. Pin 8 of A71 is connected to pin 4 and the +V power supply. Pin 6 is connected to the common terminal via C72. Pin 3 is connected to pin 6 via R703. Pin 3 also serves as the output of the discharge detection circuit and is connected to the central control unit. Pin 1 of A71 is connected to the common terminal.

[0030] Preferably, the transmitter further includes a beam current detection circuit, which includes an operational amplifier A74, resistors R712 to R714, and a capacitor C75.

[0031] In the beam branch, the K pole of Z1 is connected to the inverting output terminal of A74 via R712. The two ends of R713 are connected to the inverting input terminal and the output terminal of A74, respectively. The output terminal of A74 is connected to one end of R714. The other end of R714 is connected to one end of C75 and then serves as the output terminal of the beam detection circuit, which is connected to the central control unit. The non-inverting input terminal of A74 and the other end of C75 are connected to the common terminal.

[0032] Preferably, the central control unit includes a fiber optic serial port, a memory, an analog-to-digital converter, a digital input port, a central processing unit, and a digital-to-analog converter; the fiber optic serial port, the memory, the analog-to-digital converter, the digital input port, and the digital-to-analog converter are all connected to the central processing unit;

[0033] The fiber optic serial port is connected to the central control device and is used to realize data transmission between the central control device and the central processing unit;

[0034] The memory is used to store and retrieve the set parameters and sampled data;

[0035] The analog-to-digital converter is connected to the transmitter and is used to receive the electron gun operating parameters acquired by the transmitter, convert them into corresponding digital signals, and send them to the central processing unit.

[0036] The digital input port is connected to the transmitter and is used to acquire the discharge signal u acquired by the transmitter. δ And send it to the central processing unit;

[0037] The central processing unit is used to receive the operating mode and setting parameters sent from the central control device from the fiber optic serial port and store them in the memory; it is used to collect the electron gun operating parameters through the transmitter, and select the operating parameters as feedback quantities and digital adjustment modes according to different operating modes, and perform adjustment calculations on the corresponding setting parameters and feedback quantities to obtain the grid bias voltage control signal u. k And send it to the regulating tube, and also use it to obtain a discharge fault signal through the transmitter. Once the discharge signal u δ When the signal is active high, the adjustment operation stops, and the central control device is notified.

[0038] The digital-to-analog converter is connected to the regulating tube and is used to convert the digital signal u k u converted into an analog signal k And send it to the regulating tube.

[0039] Preferably, it further includes a drive circuit, which is connected to the central control unit and the regulating transistor respectively, and is used to transmit the gate bias voltage control signal u output by the central control unit.k Amplified into the driving signal u of the regulating tube K This drives the regulating transistor, which includes operational amplifier A51, capacitor C51, resistors R51 to R56 and diodes D51 to D52.

[0040] The non-inverting input of A51 is connected to R51, C51, and R53 respectively. The other end of R51 is connected to one end of the digital-to-analog converter. The inverting input of A51 is connected to R52 and R54 respectively. The other ends of C51, R53, and R52 are all connected to the common terminal. The other end of R54 is also connected to the output of A51. The output of A51 is also connected to the A terminal of D51. The K terminal of D51 is connected to the K terminal of D52 and R55 respectively. The other end of R55 is connected to R56 as the output of the drive circuit and connected to the control terminal of the regulating tube. The other end of R56 is connected to the -V power supply. The A terminal of D52 is connected to the output of the discharge detection circuit.

[0041] During normal operation, u δ When the voltage is low (0V), the output-input characteristic of the driving circuit is:

[0042] When discharging u δ It is a high level +V. The regulating tube operates in a saturated conduction state.

[0043] Preferably, it also includes a transformer, an auxiliary power supply, and a rectifier and filter unit;

[0044] The transformer is used for voltage transformation and electrical insulation between windings, including winding I, winding II and winding III. Winding I is a primary winding connected to the power supply, winding II and winding III are secondary windings. Winding II is connected to the input terminal of the auxiliary power supply unit, and winding III is connected to the input terminal of the rectifier and filter unit.

[0045] The auxiliary power supply unit rectifies, filters, and / or transforms the AC power from the second winding to output multiple stable DC power supplies for auxiliary power supply, including but not limited to the +V power supply in the discharge detection circuit and the -V power supply in the drive circuit;

[0046] The negative output terminal of the rectifier and filter unit is connected to the grid bias of the electron gun, and the positive output terminal is connected to the input terminal of the regulating tube. The rectifier and filter unit is used to rectify the AC power into pulsating DC power, and then output a flat, uncontrollable DC power after filtering.

[0047] A method for multimode control of electron beam current in an electron beam welding machine includes the following steps:

[0048] Obtain the operating mode and setting parameters; according to different operating modes, select the corresponding setting parameters and the corresponding operating parameters as feedback quantities, and perform adjustment calculations on the setting parameters and the feedback quantities to obtain the gate bias voltage control signal u. k And send it to the control terminal of the regulating tube;

[0049] Simultaneously, the discharge signal u is detected. δ Once the discharge signal u δ When the signal is active high, the adjustment operation stops, and the central control device is notified.

[0050] Specifically, the gate bias voltage control signal u is obtained by acquiring feedback quantities according to different operating modes. k The specific content includes:

[0051] S1. Gate bias voltage closed-loop regulation mode, select the set parameter as the cutoff gate bias voltage amplitude. The feedback quantity is the gate bias voltage signal u. G Regarding the set parameters and the feedback quantity u G The deviation is adjusted by calculation, and the result is used as the gate bias voltage control signal u. k and record u k As the cutoff gate bias voltage control signal u k0 ;

[0052] S2. Obtain a valid command to start the electron beam, determine the operating mode, and obtain the gate bias voltage control signal u according to different methods based on different operating modes. k Achieving different electron beam control:

[0053] In microbeam operating mode, select the set parameter as microbeam amplitude. The feedback quantity is the microbeam signal u' B Regarding the set parameters and the feedback quantity u' B The deviation is adjusted by calculation, and the result is then compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u. k ;

[0054] In the normal beam operating mode, the set parameter is selected as the electron beam current amplitude. The feedback quantity is the electron beam signal u. B Regarding the set parameters and the feedback quantity u B The deviation is adjusted by calculation, and the result is then compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u.k ;

[0055] In the pulse beam operating mode, the acquired setting parameters also include the large beam current amplitude. Small beam amplitude The duration τ of the large beam within one pulse cycle H The duration τ of a small beam within a pulse period L ;

[0056] In τ H Inside, with a large beam amplitude The set parameters are the electron beam signal u. B For the feedback quantity, the set parameter and the feedback quantity u B The deviation is adjusted by calculation, and the result is then compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u. k ;

[0057] In τ L Inside, with a small beam amplitude The set parameters are the electron beam signal u. B For the feedback quantity, the set parameter and the feedback quantity u B The deviation is adjusted by calculation, and the result is then compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u. k .

[0058] As can be seen from the above technical solution, compared with the prior art, the present invention discloses an electron beam current multimode control system and method for an electron beam welding machine, which has the following beneficial effects:

[0059] 1. The system disclosed in this invention has a simple structure and can flexibly and effectively control the electron beam in multiple modes;

[0060] 2. The electron gun operating parameters are sampled at the high-voltage end, and the sampled signal has higher accuracy and signal-to-noise ratio than the conventional low-voltage end sampled signal;

[0061] 3. Fast electron beam current adjustment speed, enabling control of 4-parameter pulsed electron beam;

[0062] 4. High precision in electron beam current adjustment, especially in achieving stable control of micro-beams (below 0.1mA) on high-power electron beam welding machines, which is beneficial for imaging secondary electrons or backscattered electrons and facilitates non-destructive tracing and tracking of weld seams. Attached Figure Description

[0063] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0064] Figure 1 is a schematic diagram of the structure of an electron beam current multimode control system for an electron beam welding machine provided by the present invention;

[0065] Figure 2 is a schematic diagram of the transmitter circuit in an electron beam current multimode control system for an electron beam welding machine provided by the present invention.

[0066] Figure 3 is a schematic diagram of the accelerated power supply discharge detection and protection waveform in an electron beam current multimode control system for an electron beam welding machine provided by the present invention.

[0067] Figure 4 is a schematic diagram of the central controller structure in an electron beam multimode control system for an electron beam welding machine provided by the present invention.

[0068] Figure 5 is a schematic diagram of the drive circuit in an electron beam current multimode control system for an electron beam welding machine provided by the present invention.

[0069] Figure 6 is a flowchart of an electron beam current multimode control method for an electron beam welding machine provided by the present invention.

[0070] Figure 7 is a block diagram of the cutoff gate bias voltage control provided by the present invention;

[0071] Figure 8 is a block diagram of the microbeam control provided by the present invention;

[0072] Figure 9 is a block diagram of the conventional beam control provided by the present invention;

[0073] Figure 10 is a block diagram of the pulse beam control provided by the present invention;

[0074] Figure 11 is a schematic diagram of the pulse beam control waveform provided by the present invention.

[0075] Wherein: 1-Transformer, 2-Auxiliary power supply, 3-Rectifier and filter unit; 4-Regulating tube, 5-Drive circuit; 6-Central control unit, 61-Central processor, 62-Memory, 63-Digital input port, 64-Analog-to-digital converter, 65-Digital-to-analog converter, 66-Fiber optic serial port, 7-Transmitter, 8-Fiber optic cable; 9-Master control device, 10-Bias branch, 11-Beam branch, 12-High voltage branch, 13-Accelerating power supply. Detailed Implementation

[0076] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0077] This invention discloses an electron beam current multimode control system for an electron beam welding machine, as shown in Figure 1, including: a main control device 9, a central control unit 6, an electron gun working circuit, a transmitter 7, and a regulating tube 4;

[0078] The main control device 9 is connected to the central control unit 6 and is used to send the working mode and setting parameters to the central control unit 6, and to receive the electron gun operating parameters collected by the central control unit 6.

[0079] The central control unit 6 is also connected to the transmitter 7, the regulating tube 4, and the electron gun operating circuit. It is used to acquire the operating parameters of the electron gun through the transmitter 7, and select the operating parameters as feedback quantities according to different operating modes. After adjusting the corresponding set parameters and feedback quantities, the grid bias voltage control signal u is obtained. k It is sent to the regulating tube 4 and is also used to obtain the discharge fault signal through the transmitter 7. Once the discharge signal u δ The signal is active high, the adjustment operation is stopped, and the central control unit 9 is notified.

[0080] The transmitter 7 is also connected to the electron gun working circuit to acquire the sampling signal in the electron gun working circuit, and then the acquired sampling signal is shaped, amplified and sent to the central control unit 6.

[0081] The regulating transistor 4 is also connected to the electron gun operating circuit. The output terminal of the regulating transistor 4 is connected to the common terminal and is used to control the gate bias voltage signal u. k To adjust the output gate bias voltage U of the electron gun operating circuit g This allows for adjustment of the electron beam current;

[0082] The operating modes include gate bias voltage closed-loop regulation mode, micro-beam operating mode, conventional beam operating mode and pulse beam operating mode;

[0083] In closed-loop regulation mode of gate bias voltage, the set parameter is the cutoff gate bias voltage amplitude. The feedback quantity is the gate bias voltage signal u G After the grid bias voltage is adjusted and calculated by the central control unit 6, the grid bias voltage control signal u is output. k And recorded as the cutoff gate bias voltage control signal u k0 ;

[0084] In microbeam operating mode, the set parameters include microbeam amplitude. The feedback quantity is a micro-beam signal u' B Through the micro-beam adjustment calculation of the central control unit 6, the calculation result is compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u. k ;

[0085] In conventional beam operating mode, the set parameters include electron beam current amplitude. The feedback quantity is the electron beam signal u B Through the electron beam current adjustment calculation of the central control unit 6, the calculation result is compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u. k ;

[0086] In pulse beam operating mode, the setting parameters also include large beam current amplitude. Small beam amplitude The duration τ of the large beam within one pulse cycle H The duration τ of a small beam within a pulse period L ;

[0087] In τ H Inside, with a large beam amplitude To set parameters, the electron beam signal u B As a feedback quantity, the large beam current is adjusted and calculated by the central control unit 6, and the calculation result is compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u. k ;

[0088] In τ L Inside, with a small beam amplitude To set parameters, the electron beam signal u B As a feedback quantity, the small beam current is adjusted and calculated by the central control unit 6, and the calculation result is compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u. k .

[0089] In this embodiment:

[0090] The regulating tube 4 can be a bipolar transistor, field-effect transistor, IGBT, or vacuum tube, etc.

[0091] To further implement the above technical solution, the electron gun working circuit includes a bias branch 10, which includes a resistor R1 and a resistor R2 connected together. One end of R1 and R2 is connected to the transmitter 7 as the output terminal of the bias branch 10. The other end of R1 is connected to the grid bias of the electron gun, and the other end of R2 is connected to the output terminal of the regulating tube 4 and the cathode of the electron gun, respectively.

[0092] In this embodiment:

[0093] The output terminal of bias branch 10 outputs the gate bias voltage sampling signal u. g ,

[0094] To further implement the above technical solution, the electron gun working circuit also includes a beam branch 11, a high voltage branch 12, and an acceleration power supply 13.

[0095] The beam branch 11 includes resistors R3 and R4 and Zener diode Z1. One end of R3 and R4 is connected to the K terminal of Z1, the other end of R3 is connected to the cathode of the electron gun, and the other end of R4 is connected to the A terminal of Z1. Both the K terminal and the A terminal of Z1 are connected to the transmitter 7. Furthermore, the resistance value of resistor R4 is much greater than that of resistor R3.

[0096] The high-voltage branch 12 includes connected R5 and R6. One end of R5 and R6 is connected to the transmitter 7 as the output terminal of the high-voltage branch 12. The other end of R5 is connected to the A pole of Z1 and the negative output terminal of the acceleration power supply 13 respectively. The other end of R6 is connected to the positive output terminal of the acceleration power supply 13.

[0097] The positive output terminal of the acceleration power supply 13 is grounded.

[0098] In this embodiment:

[0099] In beam branch 11, the resistance of resistor R4 is much greater than that of resistor 3. When the microbeam is working, the Zener diode Z1 does not break down, and the A terminal of Z1 outputs the microbeam sampling signal u'. b ,u' b =(R3+R4)I b ≈R4×I b When not operating under microbeam conditions, Zener diode Z1 breaks down, and the electron beam sampling signal u is output from the K-terminal of Z1. b u b =R4×I b .

[0100] The high-voltage sampling signal u is output between the output terminal of high-voltage branch 12 and the A electrode of Z1 in beam branch 11. a , The output voltage of high-voltage branch 12 relative to the common terminal is u' a ,u' a=u a +u' b .

[0101] To further implement the above technical solution, as shown in Figure 2, the transmitter 7 includes a bias detection circuit, which includes an operational amplifier A75, a resistor R715, a resistor R716, a resistor R717, and a capacitor C76.

[0102] The output of bias branch 10 is connected to the inverting input of A75 via R715. The two ends of R716 are connected to the inverting input and the output of A75, respectively. The output of A75 is connected to one end of R717. The other end of R717 is connected to one end of C76 and then serves as the output of the bias detection circuit, which is connected to the central control unit 6. The non-inverting input of A75 is connected to the other end of C76 and then connected to the common terminal.

[0103] In this embodiment:

[0104] Op-amp A75 output

[0105] To further implement the above technical solution, the transmitter 7 includes a microbeam detection circuit, a high voltage detection circuit, and a discharge detection circuit;

[0106] The microbeam detection circuit includes operational amplifier A73, resistors R709 to R711, and capacitor C74. In beam branch 11, the A terminal of Z1 is connected to the inverting output terminal of A73 via R709. The two ends of R710 are connected to the inverting input terminal and the output terminal of A73, respectively. The output terminal of A73 is connected to one end of R711. The other end of R711 is connected to one end of C74 and then serves as the output terminal of the microbeam detection circuit, which is connected to the central control unit 6. The non-inverting input terminal of A73 is connected to the other end of C74 and then connected to the common terminal.

[0107] The high-voltage detection circuit includes operational amplifier A72, resistors R704 to R708, and capacitor C73. The output of high-voltage branch 12 is connected to the non-inverting input of A72 via R705. The A terminal of Z1 in beam branch 11 is also connected to the inverting input of A72 via R704. The two ends of R707 are connected to the inverting input and output of A72, respectively. The output of A72 is connected to one end of R708. The other end of R708 is connected to one end of C73 and then serves as the output of the high-voltage detection circuit, which is connected to the central control unit 6. The other end of C73 is connected to the common terminal. The non-inverting input of A72 is also connected to the common terminal via R706.

[0108] The discharge detection circuit includes a 555 timer chip A71, resistors R701 to R703, capacitors C71 and C72, forming a monostable circuit. The output of A72 is connected to pin 2 of A71 via C71 and R702. R701 is connected to pins 2 and 8 of A71. Pin 8 of A71 is connected to pin 4 and the +V power supply. Pin 6 is connected to the common terminal via C72. Pin 3 is connected to pin 6 via R703. Pin 3 also serves as the output of the discharge detection circuit and is connected to the central control unit. Pin 1 of A71 is connected to the common terminal.

[0109] In this embodiment:

[0110] The output of op-amp A72 is

[0111] Let R704 = R705 and R706 = R707.

[0112] but

[0113] Op-amp A73 output

[0114] In the discharge detection circuit, when discharging, the high-voltage sampling signal u a Sudden drop, u 72 The output of A71 is flipped to a positive level by being triggered by C71 and R702. δ Resistor R703 and capacitor C72 form a positive voltage u. δ The circuit with a duration of τ is shown in Figure 3, and the discharge signal u δ The electrodes are respectively fed into the A terminal of diode D52 in drive circuit 5 and one end of digital input port 63;

[0115] To further implement the above technical solution, the transmitter 7 also includes a beam current detection circuit, which includes an operational amplifier A74, resistors R712 to R714 and a capacitor C75.

[0116] In beam branch 11, the K pole of Z1 is connected to the inverting output terminal of A74 via R712. The two ends of R713 are connected to the inverting input terminal and the output terminal of A74, respectively. The output terminal of A74 is connected to one end of R714. The other end of R714 is connected to one end of C75 and then serves as the output terminal of the beam detection circuit, which is connected to the central control unit 6. The non-inverting input terminal of A74 and the other end of C75 are connected to the common terminal.

[0117] In this embodiment:

[0118] Op-amp A74 output

[0119] To further implement the above technical solution, as shown in Figure 4, the central control unit 6 includes a fiber optic serial port 66, a memory 62, an analog-to-digital converter 64, a digital input port 63, a central processing unit 61, and a digital-to-analog converter 65; the fiber optic serial port 66, the memory 62, the analog-to-digital converter 64, the digital input port 63, and the digital-to-analog converter 65 are all connected to the central processing unit 61.

[0120] The fiber optic serial port 66 is connected to the central control device 9 to realize data transmission between the central control device 9 and the central processing unit 61.

[0121] Memory 62 is used to store and retrieve set parameters and sampled data;

[0122] The analog-to-digital converter 64 is connected to the transmitter 7 and is used to receive the electron gun operating parameters acquired by the transmitter 7, convert them into corresponding digital signals, and send them to the central processing unit 61.

[0123] Digital input port 63 is connected to transmitter 7 and is used to acquire the discharge signal u acquired by transmitter 7. δ And send it to the central processing unit 61;

[0124] The central processing unit 61 is used to receive the operating mode and setting parameters sent from the central control device 9 from the fiber optic serial port 66 and store them in the memory 62; it is used to collect the electron gun operating parameters through the transmitter 7, and select the operating parameters as feedback quantities and digital adjustment modes according to different operating modes, and obtain the grid bias voltage control signal u after adjusting the corresponding setting parameters and feedback quantities. k It is sent to the regulating tube 4 and is also used to obtain the discharge fault signal through the transmitter 7. Once the discharge signal u δ The signal is active high, the adjustment operation is stopped, and the main control device 9 is notified.

[0125] The digital-to-analog converter 65 is connected to the regulating transistor 4 and is used to convert the digital signal u k u converted into an analog signal k And send it to regulating tube 4.

[0126] To further implement the above technical solution, as shown in Figure 5, a drive circuit 5 is also included. The drive circuit 5 is connected to the central control unit 6 and the regulating tube 4, respectively, and is used to control the gate bias voltage output by the central control unit 6. k Amplified into the driving signal u of the regulating transistor 4 K This drives the regulating transistor 4, which includes operational amplifier A51, capacitor C51, resistors R51 to R56 and diodes D51 to D52.

[0127] The non-inverting input of A51 is connected to R51, C51, and R53 respectively. The other end of R51 is connected to one end of the digital-to-analog converter 65. The inverting input of A51 is connected to R52 and R54 respectively. The other ends of C51, R53, and R52 are all connected to the common terminal. The other end of R54 is also connected to the output of A51. The output of A51 is also connected to the A terminal of D51. The K terminal of D51 is connected to the K terminal of D52 and R55 respectively. The other end of R55 is connected to R56 as the output of the drive circuit 5 and connected to the control terminal of the regulating tube 4. The other end of R56 is connected to the -V power supply. The A terminal of D52 is connected to the output of the discharge detection circuit.

[0128] During normal operation, u δ When the voltage is low (0V), the output-input characteristic of driver circuit 5 is:

[0129] When discharging u δ It is a high level +V. The regulating tube 4 operates in a saturated conduction state.

[0130] To further implement the above technical solution, transformer 1, auxiliary power supply 2, and rectifier and filter unit 3 are also included;

[0131] Transformer 1 is used for voltage transformation and electrical insulation between windings, including winding I, winding II and winding III. Winding I is the primary winding connected to the power supply, winding II and winding III are secondary windings. Winding II is connected to the input terminal of auxiliary power supply unit 2, and winding III is connected to the input terminal of rectifier and filter unit 3.

[0132] The auxiliary power supply unit 2 rectifies, filters and / or transforms the AC power of the second winding and outputs multiple stable DC power supplies for auxiliary power supply, including but not limited to the +V power supply in the discharge detection circuit and the -V power supply in the drive circuit 5.

[0133] The negative output terminal of the rectifier filter unit 3 is connected to the grid bias of the electron gun, and the positive output terminal is connected to the input terminal of the regulating tube 4. The rectifier filter unit 3 is used to rectify the AC power into pulsating DC power, and then output a flat uncontrollable DC power after filtering.

[0134] A method for multimode control of electron beam current in an electron beam welding machine, as shown in Figure 6, includes the following steps:

[0135] Obtain the operating mode and setting parameters; based on different operating modes, select the corresponding setting parameters and operating parameters as feedback quantities, and obtain the gate bias voltage control signal u by adjusting the setting parameters and feedback quantities. k And send it to the control terminal of regulating tube 4;

[0136] Simultaneously, the discharge signal u is detected. δ Once the discharge signal u δ The signal is active high, the adjustment operation is stopped, and the central control unit 9 is notified.

[0137] Specifically, the gate bias voltage control signal u is obtained by acquiring feedback quantities according to different operating modes. k The specific content includes:

[0138] S1. Gate bias voltage closed-loop regulation mode, select the setting parameter as the cutoff gate bias voltage amplitude. The feedback quantity is the gate bias voltage signal u G , for setting parameters and feedback quantity u G The deviation is adjusted by calculation, and the result is used as the gate bias voltage control signal u. k and record u k As the cutoff gate bias voltage control signal u k0 ;

[0139] S2. Obtain a valid command to start the electron beam, determine the operating mode, and obtain the gate bias voltage control signal u according to different methods based on different operating modes. k Achieving different electron beam control:

[0140] In microbeam working mode, select the setting parameter as microbeam amplitude. The feedback quantity is a micro-beam signal u' B , for setting parameters and feedback quantity u' B The deviation is adjusted by calculation, and the result is then compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u. k ;

[0141] In the normal beam operating mode, select the setting parameter as electron beam current amplitude. The feedback quantity is the electron beam signal u B , for setting parameters and feedback quantity u B The deviation is adjusted by calculation, and the result is then compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u. k ;

[0142] In pulse beam operating mode, the acquired setting parameters also include the large beam current amplitude. Small beam amplitude The duration τ of the large beam within one pulse cycle H The duration τ of a small beam within a pulse period L ;

[0143] In τ H Inside, with a large beam amplitude To set parameters, the electron beam signal u B As feedback quantity, for setting parameters and feedback quantity u B The deviation is adjusted by calculation, and the result is then compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u. k ;

[0144] In τ L Inside, with a small beam amplitude To set parameters, the beam signal u B As feedback quantity, for setting parameters and feedback quantity u B The deviation is adjusted by calculation, and the result is then compared with the cutoff gate bias voltage control signal u. k0 Perform a subtraction operation, and use the difference as the gate bias voltage control signal u. k .

[0145] In this embodiment:

[0146] S1. Start the grid bias power supply, and the central control unit 6 controls the grid bias voltage U. g Perform digital closed-loop regulation, in order to The data is the set value, the gate bias voltage signal u G The converted data is used as a feedback quantity, and the deviation between the two is calculated by the gate bias voltage regulator to output the gate bias voltage to control u. k0 Data, as shown in Figure 7, u k0 The data is converted from digital to analog into a gate bias voltage control signal u. k Ultimately, the gate bias voltage U is achieved. g follow Data changes can be adjusted at any time by the central control device 9. data;

[0147] The gate bias voltage closed-loop regulation continues until the command to start the electron beam arrives. Therefore, once the command to start the electron beam is valid, the gate bias voltage remains unchanged until the last u. k0 The output value of the data is recorded at the end. k0 The data is then transferred to the next step.

[0148] S2. Start the electron beam; the central control unit 6 controls the electron beam I. b Digital closed-loop regulation is performed, and different regulation methods are used for the electron beam according to different operating modes:

[0149] Microbeam working mode: with The data is a set value, and the micro-beam signal is u'.B The converted data is used as a feedback quantity, and the deviation between the two is calculated by a micro-beam regulator. The cutoff gate bias voltage controls u. k0 The difference between the data and the output data of the microbeam regulator is used as the gate bias voltage control u. k Data, as shown in Figure 8, u k The data is converted from digital to analog into a gate bias voltage control signal u. k Ultimately, electron beam I was achieved. b follow Data changes can be adjusted at any time by the central control device 9. data.

[0150] Conventional beam operating mode: The data is a set value, and the electron beam signal is u. B The converted data is used as a feedback quantity, and the deviation between the two is calculated by the electron beam current regulator. The cutoff gate bias voltage controls u. k0 The difference between the data and the output data of the electron beam current conditioner is used as the gate bias voltage control u. k Data, as shown in Figure 9, u k The data is converted from digital to analog into a gate bias voltage control signal u. k Ultimately, electron beam I was achieved. b follow Data changes can be adjusted at any time by the central control device 9. data.

[0151] Pulse beam operating mode: large beam time τ H In this segment, the small beam current regulator stops working, and its output is blocked. The data is a set value, and the electron beam signal is u. B The converted data is used as a feedback quantity, and the deviation between the two is calculated by a large beam current regulator. The cutoff gate bias voltage controls u. k0 The difference between the data and the output data of the high-current regulator is used as the gate bias voltage control u. k Data, u k The data is converted from digital to analog into a gate bias voltage control signal u. k Ultimately, electron beam I was achieved. b follow Data changes; within a small time interval τ L During this phase, the high-current regulator stops working, and its output is blocked. The data is a set value, and the electron beam signal is u. B The converted data is used as a feedback quantity, and the deviation between the two is calculated by a small beam current regulator. The cutoff gate bias voltage controls u. k0 The difference between the data and the output data of the small beam current regulator is used as the gate bias voltage control u. k Data, u k The data is converted from digital to analog into a gate bias voltage control signal u.k Ultimately, electron beam I was achieved. b follow Data changes; as shown in Figure 10, the overall control device 9 for the adjustment process can be changed at any time. τ H and τ L Data; the pulse beam control waveform is shown in Figure 11.

[0152] During the above process, the central control unit 6 continuously monitors the occurrence of discharge, and once u δ When the high level is active, the central controller 61 records the current working state and stops the digital regulator, and sends a discharge fault signal to the main control unit 9. The main control unit 9 promptly cuts off the output of the acceleration power supply 13. After the discharge fault is cleared, the central control unit 6 automatically resumes the working state before the interruption.

[0153] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0154] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-mode control system for electron beam welding machines, characterized in that, include: The system comprises a central control unit, a central control unit, an electron gun operating circuit, a transmitter, and a regulating tube. The central control unit is connected to the central control unit and is used to send the operating mode and set parameters to the central control unit, and to receive the electron gun operating parameters collected by the central control unit. The central control unit is also connected to the transmitter, the regulating tube, and the electron gun operating circuit, and is used to select the electron gun operating parameters as feedback quantities according to different operating modes based on the electron gun operating parameters collected by the transmitter, and to adjust the corresponding set parameters and the feedback quantities to obtain the grid bias voltage control signal. And send it to the regulating tube, and also use it to obtain a discharge fault signal through the transmitter, once the discharge signal is received... The signal is active high, stopping the adjustment operation. The transmitter is also connected to the electron gun operating circuit to acquire the sampling signal within the electron gun operating circuit, and then shapes and amplifies the acquired sampling signal before sending it to the central control unit. The regulating tube is also connected to the electron gun operating circuit, and its output terminal is connected to a common terminal, used to control the signal according to the gate bias voltage. To adjust the gate bias voltage of the electron gun operating circuit This allows for adjustment of the electron beam current; the operating modes include gate bias voltage closed-loop adjustment mode, micro-beam operating mode, conventional beam operating mode, and pulsed beam operating mode; in the gate bias voltage closed-loop adjustment mode, the set parameter is the cutoff gate bias voltage amplitude. The feedback quantity is the gate bias voltage signal. The gate bias voltage control signal is output after the gate bias voltage adjustment calculation by the central control unit. And recorded as the cutoff gate bias voltage control signal. In the microbeam operating mode, the set parameters include the microbeam amplitude. The feedback quantity is a micro-beam signal. Through the micro-beam adjustment calculation of the central control unit, the calculation result is compared with the cutoff gate bias voltage control signal. The subtraction operation is performed, and the difference is used as the gate bias voltage control signal. In the conventional beam operating mode, the set parameters include the electron beam current amplitude. The feedback quantity is the electron beam signal. The calculation results, obtained through the electron beam current adjustment operation of the central control unit, are compared with the cutoff gate bias voltage control signal. The subtraction operation is performed, and the difference is used as the output gate bias voltage control signal. In the pulse beam operating mode, the setting parameters also include a large beam current amplitude. Small beam amplitude Duration of large beam current within one pulse cycle Duration of small beam current within a pulse period ;exist Inside, with a large beam amplitude The set parameters are the electron beam signal u. B The feedback quantity is calculated by the central control unit using a large beam current adjustment method. The calculation result is then compared with the cutoff gate bias voltage control signal. The subtraction operation is performed, and the difference is used as the output gate bias voltage control signal. ;exist Inside, with a small beam amplitude The set parameters are based on the electron beam signal. The feedback quantity is calculated by the small beam current adjustment of the central control unit, and the calculation result is compared with the cutoff gate bias voltage control signal. The subtraction operation is performed, and the difference is used as the output gate bias voltage control signal. 。 2. The electron beam current multi-mode control system for an electron beam welding machine according to claim 1, characterized in that, The electron gun operating circuit includes a bias branch, which includes connected resistors R1 and R2. One end of R1 and R2 is connected to the transmitter as the output terminal of the bias branch. The other end of R1 is connected to the grid bias of the electron gun, and the other end of R2 is connected to the output terminal of the regulating tube and the cathode of the electron gun, respectively.

3. The electron beam current multimode control system for an electron beam welding machine according to claim 1, characterized in that, The electron gun operating circuit also includes a beam branch, a high-voltage branch, and an accelerating power supply. The beam branch includes resistors R3 and R4 and a Zener diode Z1. One end of both R3 and R4 is connected to the base (K) of Z1, the other end of R3 is connected to the electron gun cathode, and the other end of R4 is connected to the anode (A) of Z1. Both the base (K) and anode (A) of Z1 are connected to the transmitter. The resistance of R4 is greater than that of R3. The high-voltage branch includes connected resistors R5 and R6. One end of R5 and R6 is connected to the transmitter as the high-voltage branch output. The other end of R5 is connected to the anode (A) of Z1 and the negative output terminal of the accelerating power supply, respectively. The other end of R6 is connected to the positive output terminal of the accelerating power supply. The positive output terminal of the accelerating power supply is grounded.

4. The electron beam current multimode control system for an electron beam welding machine according to claim 2, characterized in that, The transmitter includes a bias detection circuit, which comprises an operational amplifier A75, resistors R715, R716, and R717, and a capacitor C76. The output of the bias branch is connected to the inverting input of A75 via R715. The two ends of R716 are connected to the inverting input and the output of A75, respectively. The output of A75 is connected to one end of R717. The other end of R717 is connected to one end of C76 and serves as the output of the bias detection circuit, which is then connected to the central control unit. The non-inverting input of A75 and the other end of C76 are connected to a common terminal.

5. The electron beam current multimode control system for an electron beam welding machine according to claim 3, characterized in that, The transmitter includes a micro-beam detection circuit, a high-voltage detection circuit, and a discharge detection circuit. The micro-beam detection circuit includes an operational amplifier A73, resistors R709-R711, and a capacitor C74. In the beam branch, the A terminal of Z1 is connected to the inverting output terminal of A73 via R709. The two ends of R710 are connected to the inverting input terminal and the output terminal of A73, respectively. The output terminal of A73 is connected to one end of R711. The other end of R711 is connected to one end of C74 and serves as the output terminal of the micro-beam detection circuit, which is connected to the central control unit. The non-inverting input terminal of A73 is connected to the other end of C74 and then connected to a common terminal. The high-voltage detection circuit includes an operational amplifier A72, resistors R704-R708, and a capacitor C73. The output terminal of the high-voltage branch is connected to the non-inverting input terminal of A72 via R705. In the beam branch, the A terminal of Z1 is also connected to the inverting input terminal of A72 via R704. The two ends of 707 are connected to the inverting input and output of A72, respectively. The output of A72 is connected to one end of R708. The other end of R708 is connected to one end of C73 and serves as the output of the high-voltage detection circuit, which is connected to the central control unit. The other end of C73 is connected to the common terminal. The non-inverting input of A72 is also connected to the common terminal via R706. The discharge detection circuit includes a 555 timer chip A71, resistors R701~R703, capacitors C71 and C72, forming a monostable circuit. The output of A72 is connected to pin 2 of A71 via C71 and R702. R701 is connected to pins 2 and 8 of A71. Pin 8 of A71 is connected to pin 4 and the +V power supply. Pin 6 is connected to the common terminal via C72. Pin 3 is connected to pin 6 via R703. Pin 3 also serves as the output of the discharge detection circuit, which is connected to the central control unit. Pin 1 of A71 is connected to the common terminal.

6. The electron beam current multimode control system for an electron beam welding machine according to claim 3, characterized in that, The transmitter also includes a beam current detection circuit, which includes an operational amplifier A74, resistors R712-R714, and capacitor C75. In the beam current branch, the K-terminal of Z1 is connected to the inverting output terminal of A74 via R712. The two ends of R713 are connected to the inverting input terminal and the output terminal of A74, respectively. The output terminal of A74 is connected to one end of R714. The other end of R714 is connected to one end of C75 and then serves as the output terminal of the beam current detection circuit, which is connected to the central control unit. The non-inverting input terminal of A74 and the other end of C75 are connected to a common terminal.

7. The electron beam current multimode control system for an electron beam welding machine according to claim 1, characterized in that, The central control unit includes a fiber optic serial port, a memory, an analog-to-digital converter (ADC), a digital input port, a central processing unit (CPU), and a digital-to-analog converter (DAC). The fiber optic serial port, the memory, the ADC, the digital input port, and the DAC are all connected to the CPU. The fiber optic serial port connects to the central control device, enabling data transmission between the central control device and the CPU. The memory is used to store and retrieve the set parameters and sampled data. The analog-to-digital converter is connected to the transmitter and is used to receive the electron gun operating parameters acquired by the transmitter, convert them into corresponding digital signals, and send them to the central processing unit; the digital input port is connected to the transmitter and is used to acquire the discharge signal acquired by the transmitter. The data is then sent to the central processing unit; the central processing unit is used to receive the operating mode and setting parameters sent from the central control device from the fiber optic serial port, and store them in the memory. The transmitter collects electron gun operating parameters, and selects these parameters as feedback values ​​and digital adjustment modes according to different operating modes. The corresponding set parameters are then adjusted and calculated with the feedback values ​​to obtain the grid bias voltage control signal. And send it to the regulating tube, and also use it to obtain a discharge fault signal through the transmitter, once the discharge signal is received... The signal is active high, stopping the adjustment operation and notifying the central control device; the digital-to-analog converter is connected to the adjustment transistor and is used to convert the digital signal... Converted into analog signal And send it to the regulating tube.

8. The electron beam current multimode control system for an electron beam welding machine according to claim 1, characterized in that, It also includes a drive circuit, which is connected to the central control unit and the regulating transistor respectively, and is used to transmit the gate bias voltage control signal output by the central control unit. Amplified into a control tube drive signal This drives the regulating transistor, which includes operational amplifier A51, capacitor C51, resistors R51~R56, and diodes D51~D52. The non-inverting input of A51 is connected to R51, C51, and R53, and the other end of R51 is connected to one end of the digital-to-analog converter. The inverting input of A51 is connected to R52 and R54, and the other ends of C51, R53, and R52 are all connected to a common terminal. The other end of R54 is also connected to the output of A51, and the output of A51 is also connected to the A terminal of D51. The K terminal of D51 is connected to the K terminal of D52 and R55, and the other end of R55 is connected to R56 as the output of the drive circuit, which is connected to the control terminal of the regulating transistor. The other end of R56 is connected to the -V power supply, and the A terminal of D52 is connected to the output of the discharge detection circuit. In normal operation... When the voltage is low (0V), the output-input characteristic of the driving circuit is: When discharging It is a high level +V. The regulating tube operates in a saturated conduction state.

9. The electron beam current multimode control system for an electron beam welding machine according to claim 8, characterized in that, It also includes a transformer, an auxiliary power supply unit, and a rectifier and filter unit. The transformer is used for voltage transformation and electrical insulation between the windings, including a first winding, a second winding, and a third winding. The first winding is the primary winding connected to the power supply, and the second and third windings are the secondary windings. The second winding is connected to the input terminal of the auxiliary power supply unit, and the third winding is connected to the input terminal of the rectifier and filter unit. The auxiliary power supply unit rectifies, filters, and / or transforms the AC power from the second winding to output multiple stable DC power supplies for auxiliary power supply, including but not limited to the +V power supply in the discharge detection circuit and the -V power supply in the drive circuit. The negative output terminal of the rectifier and filter unit is connected to the grid bias of the electron gun, and the positive output terminal is connected to the input terminal of the regulating tube. The rectifier and filter unit is used to rectify the AC power into pulsating DC power, and then output a flat, uncontrollable DC power after filtering.

10. A method for multi-mode control of electron beam current in an electron beam welding machine, characterized in that, Includes the following steps: Obtain the operating mode and setting parameters; according to different operating modes, select the corresponding setting parameters and corresponding electron gun operating parameters as feedback quantities, and perform adjustment calculations on the setting parameters and the feedback quantities to obtain the grid bias voltage control signal. The signal is sent to the control terminal of the regulating tube; simultaneously, the discharge signal is detected. Once the discharge signal When the signal is active high, the adjustment operation stops, and the central control unit is notified; in this process, feedback quantities are obtained according to different operating modes to obtain the gate bias voltage control signal. The specific content includes: S1. Gate bias voltage closed-loop adjustment mode, where the set parameter is selected as the cutoff gate bias voltage amplitude. The feedback quantity is the gate bias voltage signal. Regarding the set parameters and the feedback quantity The deviation is adjusted using calculations, and the result is used as the gate bias voltage control signal. and record As the cutoff gate bias voltage control signal S2. Obtain a valid command to start the electron beam, determine the operating mode, and obtain the gate bias voltage control signal according to different methods based on different operating modes. To achieve different electron beam current control: In microbeam operating mode, select the set parameter as the microbeam amplitude. The feedback quantity is a micro-beam signal. Regarding the set parameters and the feedback quantity The deviation is adjusted by calculation, and the result is then compared with the cutoff gate bias voltage control signal. The subtraction operation is performed, and the difference is used as the gate bias voltage control signal. In the conventional beam operating mode, the set parameter is selected as the electron beam current amplitude. The feedback quantity is the electron beam signal. Regarding the set parameters and the feedback quantity The deviation is adjusted by calculation, and the result is then compared with the cutoff gate bias voltage control signal. The subtraction operation is performed, and the difference is used as the gate bias voltage control signal. In pulse beam operating mode, the acquired setting parameters also include the large beam current amplitude. Small beam amplitude Duration of large beam current within one pulse cycle Duration of small beam current within a pulse period ;exist Inside, with a large beam amplitude The set parameters are based on the electron beam signal. For the feedback quantity, the set parameter and the feedback quantity The deviation is adjusted by calculation, and the result is then compared with the cutoff gate bias voltage control signal. The subtraction operation is performed, and the difference is used as the gate bias voltage control signal. ;exist Inside, with a small beam amplitude The set parameters are based on the electron beam signal. For the feedback quantity, the set parameter and the feedback quantity The deviation is adjusted by calculation, and the result is then compared with the cutoff gate bias voltage control signal. The subtraction operation is performed, and the difference is used as the gate bias voltage control signal. 。

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