CN115476028B - Focusing system for electron beam welding machine - Google Patents
Focusing system for electron beam welding machine Download PDFInfo
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- CN115476028B CN115476028B CN202210698622.0A CN202210698622A CN115476028B CN 115476028 B CN115476028 B CN 115476028B CN 202210698622 A CN202210698622 A CN 202210698622A CN 115476028 B CN115476028 B CN 115476028B
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- 238000010894 electron beam technology Methods 0.000 title claims abstract description 30
- 238000003466 welding Methods 0.000 title claims abstract description 27
- 230000033228 biological regulation Effects 0.000 claims abstract description 30
- 230000003321 amplification Effects 0.000 claims abstract description 19
- 238000003199 nucleic acid amplification method Methods 0.000 claims abstract description 19
- 230000000087 stabilizing effect Effects 0.000 claims description 54
- 239000003990 capacitor Substances 0.000 claims description 48
- 238000005070 sampling Methods 0.000 claims description 7
- 230000002457 bidirectional effect Effects 0.000 claims description 6
- 230000001629 suppression Effects 0.000 claims description 6
- 230000001052 transient effect Effects 0.000 claims description 6
- 230000009123 feedback regulation Effects 0.000 claims description 3
- 230000001105 regulatory effect Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K15/00—Electron-beam welding or cutting
- B23K15/0026—Auxiliary equipment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K15/00—Electron-beam welding or cutting
- B23K15/0046—Welding
Abstract
The application provides a focusing system for an electron beam welding machine, which comprises an electron gun and a focusing coil, wherein the focusing coil is driven by a focusing driving plate, and a driving circuit of the focusing driving plate comprises a control and regulation module, an NMOSFET group module and a direct-current voltage source; the NMOSFET group module is provided with a drain terminal, a source terminal, a grid driving terminal and an overcurrent protection terminal; the positive electrode of the direct current voltage source is connected with the drain electrode end, and the negative electrode is connected with the source electrode end; the control and regulation module is used for controlling the voltage of the grid driving end; the NMOSFET group module generates a focusing current capable of driving the focusing coil between the drain terminal and the source terminal according to the voltage difference between the grid driving terminal and the drain terminal; the control and regulation module comprises a differential amplification module, a linear regulation and feedback module and a zero drift processing module. The focusing system for the electron beam welding machine has the characteristics of high precision and large adjustable range of focusing current.
Description
Technical Field
The application relates to the technical field of electron beam welding equipment, in particular to a focusing system for an electron beam welding machine.
Background
An electron beam welder is a relatively precise welding device that performs a welding process using the principle of high-speed moving electron beam current striking a workpiece, and essentially represents the highest performance welding level. The electron beam with high energy density is accelerated by the high-voltage accelerating electric field between cathode and anode, and forms dense high-speed electron flow after focusing coil action, and bombards the welding surface to melt the workpiece to be welded. Under the condition that other firmware parameters of the electron beam welding machine are the same, the position of an electron beam focus relative to a workpiece is controlled by changing focusing current in a focusing system, so that a better welding seam cross-section morphology is obtained.
The existing focusing system for the electron beam welding machine has the defects of low precision and small adjustable range of focusing current, and therefore, the application provides the focusing system for the electron beam welding machine.
Disclosure of Invention
The present application has been made in view of the above problems, and an object of the present application is to provide a focusing system for an electron beam welding machine.
The application provides a focusing system for an electron beam welding machine, which comprises an electron gun and a focusing coil, wherein the focusing coil is driven by a focusing driving plate, and a driving circuit of the focusing driving plate comprises a control and regulation module, an NMOSFET group module and a direct-current voltage source;
the NMOSFET group module is provided with a drain terminal, a source terminal, a grid driving terminal and an overcurrent protection terminal; the positive electrode of the direct-current voltage source is connected with the drain terminal, and the negative electrode of the direct-current voltage source is connected with the source terminal; the control and regulation module is connected with the grid driving end and used for controlling the voltage of the grid driving end; the NMOSFET group module generates a focusing current capable of driving the focusing coil between the drain terminal and the source terminal according to a voltage difference between the gate driving terminal and the drain terminal;
the control and regulation module comprises a differential amplification module, a linear regulation and feedback module and a zero drift processing module;
the differential amplification module is configured to receive a control signal; the control signal is an adjustable direct-current voltage signal with the voltage of 0-10V; the control signal passes through the differential amplification module and then outputs a reverse voltage signal with the same proportion;
the linear regulation and feedback module is configured to perform linear feedback regulation on the voltage signal of the gate driving end introduced into the NMOSFET group module; the linear regulation and feedback module takes the voltage signal output by the differential amplification module as an input signal and takes the voltage signal output by the source electrode end of the NMOSFET group module as a feedback signal;
the zero drift processing module is configured to adjust a zero drift of the circuit.
According to the technical scheme provided by some embodiments of the present application, the NMOSFET group module includes four groups of NMOSFET units with the same structure connected in parallel; the NMOSFET cell includes: the first resistor, the second resistor, the third resistor, the first NMOSFET, the first NPN triode, the first zener diode and the second zener diode;
the grid electrode of the first NMOSFET is connected with the first resistor, and one end, far away from the grid electrode of the first NMOSFET, of the first resistor forms a grid electrode driving end of the NMOSFET group module;
the first voltage stabilizing diode is connected in parallel between the grid electrode and the source electrode of the first NMOSFET, the positive electrode end of the first voltage stabilizing diode is connected with the source electrode of the first NMOSFET, and the negative electrode end of the first voltage stabilizing diode is connected with the grid electrode of the first NMOSFET; the second zener diode and the third resistor are connected in series and then connected with the first zener diode in parallel, and the cathode end of the second zener diode is connected with the cathode end of the first zener diode; the base electrode of the first NPN triode is connected with the positive electrode end of the first voltage stabilizing diode, the collector electrode of the first NPN triode is connected with the negative electrode end of the first voltage stabilizing diode, the emitter electrode of the first NPN triode is connected with the second resistor, and one end, far away from the first NPN triode, of the second resistor forms an overcurrent protection end of the NMOSFET group module.
According to some embodiments of the present application, the differential amplifying module includes: resistor R3, resistor R4, resistor R5, ground capacitor C3, ground capacitor C4, ground capacitor C13, ground capacitor C14, diode D7, diode D8, diode D9, diode D10, and differential amplifier IC1;
the positive end of the control signal is connected with the resistor R3 in series and then connected to the reverse input end of the differential amplifier IC1, and the negative end of the control signal is connected with the resistor R4 in series and then connected to the positive input end of the differential amplifier IC1;
the reverse input end of the differential amplifier IC1 is also connected with the grounding capacitor C3, and the positive input end of the differential amplifier IC1 is also connected with the grounding capacitor C4; the resistor R5 is also connected between the positive input end and the negative input end of the differential amplifier IC1;
the reverse input end of the differential amplifier IC1 is also connected with the negative electrode of the diode D8, and the positive electrode of the diode D8 is connected with-15V voltage; the reverse input end of the differential amplifier IC1 is also connected with the positive electrode of the diode D7, and the negative electrode of the diode D7 is connected with +15V voltage;
the positive input end of the differential amplifier IC1 is also connected with the negative electrode of the diode D10, and the positive electrode of the diode D10 is connected with-15V voltage; the positive input end of the differential amplifier IC1 is also connected with the positive electrode of the diode D9, and the negative electrode of the diode D9 is connected with +15V voltage;
the positive power supply voltage end of the differential amplifier IC1 is connected with +15V voltage and is also connected with the grounding capacitor C13; the negative power supply voltage end of the differential amplifier IC1 is connected with-15V voltage and is also connected with the grounding capacitor C14; the reference ground of the differential amplifier IC1 is grounded.
According to some embodiments of the present application, the linear adjusting and feedback module includes an operational amplifier IC3; the source electrode end is connected with the reverse input end of the operational amplifier IC3 in series with a resistor R19; the positive input end of the operational amplifier IC3 is grounded; the positive power supply voltage end of the operational amplifier IC3 is connected with +15V voltage and is also connected with a grounding capacitor C17; the negative power supply voltage end of the operational amplifier IC3 is connected with-15V voltage and is also connected with a grounding capacitor C18; the output end of the operational amplifier IC3 is connected with a common diode D11, a resistor R22 and a resistor R21 which are sequentially connected in series; the negative end of the common diode D11 is connected with the output end of the operational amplifier IC3, and the positive end of the common diode D is connected with the resistor R22; one end of the resistor R21 far away from the resistor R22 is connected with a +15V power supply; one end of the resistor R22 far away from the common diode D11 is connected with a capacitor C6; one end of the capacitor C6 far away from the resistor R22 is connected with a resistor R20; one end of the resistor R20 far away from the resistor R22 is connected with a resistor R16; the resistor R16 is also connected to the inverting input of the operational amplifier IC3; one end of the resistor R16, which is far away from the reverse input end of the operational amplifier IC3, is connected with a potentiometer R15; one end of the potentiometer R15 far away from the resistor R16 is connected with the output end of the differential amplifier IC1.
According to some embodiments of the present application, the null shift processing module includes: a potentiometer R17 and a resistor R18; the two ends of the potentiometer R17 are respectively connected with +15V voltage and-15V voltage, the adjusting end of the potentiometer R17 is connected with the resistor R18, and the other end of the resistor R18 is connected with one end of the resistor R16 far away from the potentiometer R15.
According to some embodiments of the present application, the gate driving end of the NMOSFET group module is connected to one end of the capacitor C6 away from the resistor R20;
a common diode D2, a zener diode D3, the capacitor C6 and the resistor R20 are sequentially connected in series between the drain terminal of the NMOSFET group module and the resistor R16;
a resistor R26, a zener diode D17, a common diode D16, the capacitor C6 and the resistor R20 are sequentially connected in series between the source terminal of the NMOSFET group module and the resistor R16;
a common diode D5 is connected between the source terminal and the drain terminal of the NMOSFET group module, the positive terminal of the common diode D5 is connected with the source terminal, and the negative terminal is connected with the drain terminal;
the source electrode end of the NMOSFET group module is also connected with a sampling resistor R2 and a bidirectional transient suppression diode D6 connected with the sampling resistor R2 in parallel, one end of the bidirectional transient suppression diode D6 is connected with the source electrode end, and the other end is grounded;
the grid driving end of the NMOSFET group module is also connected with a common diode D13, an NPN triode T1 and a common diode D14; the positive end of the common diode D13 is connected with the grid driving end, and the negative end of the common diode D is connected with the collector electrode of the NPN triode T1; the positive terminal of the common diode D14 is connected with the emitter of the NPN triode T1, and the negative terminal is grounded; the base electrode of the NPN triode T1 is connected with the source electrode end in series with the resistor R24; a capacitor C7 is connected in parallel between the positive electrode end of the common diode D13 and the base electrode of the NPN triode T1;
the source electrode end of the NMOSFET group module is also connected with a common diode D15 and a resistor R25 which are connected in series; the positive terminal of the common diode D15 is connected with the source terminal, and the negative terminal of the common diode D is connected with the resistor R25; one end of the resistor R25 far away from the common diode D15 is connected with a-15V power supply;
the overcurrent protection terminal of the NMOSFET group module is connected to the negative terminal of the common diode D15.
According to the technical scheme provided by some embodiments of the present application, the output end of the operational amplifier IC3 is further connected with a resistor R41 and a PNP triode T2; the base electrode of the PNP triode T2 is connected with the resistor R41, the collector electrode is connected with the grounding resistor R42, and the emitter electrode is connected with the photodiode H2; the positive electrode of the photodiode H2 is connected with a +15V power supply, and the negative electrode of the photodiode H2 is connected with the emitter of the PNP triode T2.
According to the technical scheme provided by some embodiments of the present application, a photodiode H1, a resistor R23, a zener diode D12 and the resistor R26 are further connected in series between the positive electrode and the negative electrode of the dc voltage source in sequence; the positive end of the photodiode H1 is connected with the positive electrode of the direct-current voltage source, and the negative end of the photodiode H1 is connected with the resistor R23; the positive terminal of the zener diode D12 is connected to the negative electrode of the dc voltage source, and the negative terminal is connected to the resistor R23.
Compared with the prior art, the application has the beneficial effects that: the application adjusts the size of the focusing current output by the focusing driving plate by changing the control signal of the system, thereby realizing the adjustment of the position of the electron beam focus relative to the welded workpiece and meeting the requirement of electron beam welding; specifically, after the control signal enters the focusing driving plate, a reverse voltage signal with almost the same proportion is output after passing through the differential amplification module, then the voltage difference between the grid driving end and the drain driving end of the NMOSFET group module is regulated through the linear regulation and feedback module, the focusing current capable of driving the focusing coil is controlled and output, and the focusing system has the characteristics of good linearity, high precision and large adjustable range of the focusing current by arranging the control regulation module comprising the differential amplification module, the linear regulation and feedback module and the zero drift processing module.
In some embodiments of the present application, a linear adjustment and feedback module is provided for the NMOSFET group module, when in use, an operational amplifier IC3 of the linear adjustment and feedback module and a related circuit are used for feeding back an output current signal, and a potentiometer R15 of the linear adjustment and feedback module and a potentiometer R17 of the zero drift processing module are used for carrying out linear corresponding adjustment on an input voltage control signal and the output current signal, so as to finally output a stable focusing current with excellent linear variation of 0-5000 mA;
in some embodiments of the present application, the focus driving board has a good monitoring function and can be accurately positioned when a fault occurs by setting the photodiode H1 for the direct current source input to the drain terminal of the NMOSFET group module and setting the photodiode H2 for the linear adjustment and feedback module of the NMOSFET group module.
Drawings
FIG. 1 is a schematic diagram of a focusing system for an electron beam welding machine according to an embodiment of the present application;
FIG. 2 is a schematic circuit diagram of a focusing drive plate of a focusing system for an electron beam welder according to an embodiment of the present application;
fig. 3 is a schematic circuit diagram of the NMOSFET block of fig. 2.
The text labels in the figures are expressed as:
1. an electron gun; 2. a focusing coil; 3. a work piece to be welded; 4. and a focus driving plate.
Detailed Description
In order that those skilled in the art may better understand the technical solutions of the present application, the following detailed description of the present application with reference to the accompanying drawings is provided for exemplary and explanatory purposes only and should not be construed as limiting the scope of the present application.
Referring to fig. 1, the present embodiment provides a focusing system for an electron beam welding machine, which includes: an electron gun 1 and a focusing coil 2.
The inside of the electron gun 1 is composed of a cathode, a bias cup and an anode; the electron gun 1 is connected with a power supply; the power supply provides an adjustable cathode voltage, grid bias voltage and cathode current for the electron gun 1 so as to control the size of electron beam current; different specifications of power sources, such as medium-voltage or high-voltage power sources, can be selected according to different welding requirements.
The focusing coil 2 is a ring coil; the focusing coil 2 is driven by a focusing driving plate 4; the schematic circuit diagram of the focus drive plate 4 is shown in fig. 2.
The welded workpiece 3 is located below the focusing coil 2, and when in use, the electron beam with high energy density is utilized, electrons generated by the cathode in the electron gun 1 are accelerated under the action of a high-voltage accelerating electric field between the cathode and the anode, and after the electrons are acted by the focusing coil 2, dense high-speed electron flow is formed and bombarded on the welding surface of the welded workpiece 3, so that the welded workpiece 3 is melted to realize welding.
The circuit of the focus driving board includes: the control and regulation module, the NMOSFET group module and the direct-current voltage source; the NMOSFET group module is provided with a drain terminal, a source terminal, a grid driving terminal and an overcurrent protection terminal; the voltage of the direct-current voltage source is 56V; the positive pole of the dc voltage source (i.e. c in fig. 2 + ) Connected to the drain terminal, the negative electrode (i.e., c in fig. 2 - ) Connected to the source terminal; the control and regulation module is connected with the grid driving end and used for controlling the voltage of the grid driving end; the NMOSFET group module generates a focusing current between the drain terminal and the source terminal capable of driving the focusing coil according to the voltage difference between the gate driving terminal and the drain terminal, wherein A in FIG. 2 + For focusing the positive pole of the current, A - Is the negative of the focus current.
The control and regulation module comprises a differential amplification module, a linear regulation and feedback module and a zero drift processing module;
the differential amplification module is configured to receive a control signal, wherein the control signal is a 0-10V adjustable direct voltage signal, and the control signal outputs a reverse voltage signal with nearly the same proportion after passing through the differential amplification module; the differential amplification module has the functions of isolating signals and reducing input bias current.
The differential amplifying module includes a resistor R3, a resistor R4, a resistor R5, a ground capacitor C3, a ground capacitor C4, a ground capacitor C13, a ground capacitor C14, a diode D7, a diode D8, a diode D9, a diode D10, and a differential amplifier IC1.
Control signals enter a focusing driving plate from B6 and Z6; the positive end of the control signal is connected with the resistor R3 in series and then is connected to the reverse input end of the differential amplifier IC1, and the negative end of the control signal is connected with the resistor R4 in series and then is connected to the positive input end of the differential amplifier IC1;
the reverse input end of the differential amplifier IC1 is also connected with a grounding capacitor C3, and the positive input end of the differential amplifier IC1 is also connected with a grounding capacitor C4; a resistor R5 is also connected between the positive input end and the negative input end of the differential amplifier IC1;
the reverse input end of the differential amplifier IC1 is also connected with the cathode of a diode D8, and the anode of the diode D8 is connected with-15V voltage; the reverse input end of the differential amplifier IC1 is also connected with the positive electrode of a diode D7, and the negative electrode of the diode D7 is connected with +15V voltage;
the positive input end of the differential amplifier IC1 is also connected with the negative electrode of the diode D10, and the positive electrode of the diode D10 is connected with-15V voltage; the positive input end of the differential amplifier IC1 is also connected with the positive electrode of a diode D9, and the negative electrode of the diode D9 is connected with +15V voltage;
the positive power supply voltage end of the differential amplifier IC1 is connected with +15V voltage and is also connected with a grounding capacitor C13; the negative supply voltage end of the differential amplifier IC1 is connected with-15V voltage and is also connected with a grounding capacitor C14; the reference ground of the differential amplifier IC1 is grounded;
after passing through the differential amplification module, the control signal outputs a reverse voltage signal with nearly the same proportion through the output end of the differential amplifier IC1.
The linear regulation and feedback module is configured to perform linear feedback regulation on the voltage signal of the gate driving end introduced into the NMOSFET group module; the linear regulation and feedback module takes the voltage signal output by the differential amplification module as an input signal, takes a voltage signal formed by the current output by the NMOSFET group module on the ground at the sampling resistor R2 as a feedback signal, regulates the voltage signal introduced into the grid driving end of the NMOSFET group module, and then changes the voltage difference between the grid driving end and the drain driving end of the NMOSFET group module, so that the control signal and the current output by the NMOSFET group module form a linear corresponding relation.
The linear regulation and feedback module comprises an operational amplifier IC3; the source electrode end is connected with the reverse input end of the operational amplifier IC3 in series with a resistor R19; the positive input end of the operational amplifier IC3 is grounded; the positive power supply voltage end of the operational amplifier IC3 is connected with +15V voltage and is also connected with a grounding capacitor C17; the negative power supply voltage end of the operational amplifier IC3 is connected with-15V voltage and is also connected with a grounding capacitor C18; the output end of the operational amplifier IC3 is connected with a common diode D11, a resistor R22 and a resistor R21 which are sequentially connected in series; the negative end of the common diode D11 is connected with the output end of the operational amplifier IC3, and the positive end of the common diode D is connected with the resistor R22; one end of the resistor R21 far away from the resistor R22 is connected with a +15V power supply; one end of the resistor R22 far away from the common diode D11 is connected with a capacitor C6; one end of the capacitor C6 far away from the resistor R22 is connected with a resistor R20; one end of the resistor R20 far away from the resistor R22 is connected with a resistor R16; the resistor R16 is also connected to the inverting input of the operational amplifier IC3; one end of the resistor R16, which is far away from the reverse input end of the operational amplifier IC3, is connected with a potentiometer R15; one end of the potentiometer R15 far away from the resistor R16 is connected with the output end of the differential amplifier IC1.
The zero drift processing module is configured to adjust the zero drift of the circuit; the zero drift treatment module comprises a potentiometer R17 and a resistor R18, wherein the two ends of the potentiometer R17 are respectively connected with +15V voltage and-15V voltage, the adjusting end of the potentiometer R17 is connected with the resistor R18, and the other end of the resistor R18 is connected with the end, far away from the potentiometer R15, of the resistor R16.
The zero drift concept (zero drift) can be described as: when the input signal of the amplifying circuit is zero (i.e. no alternating current is input), the static working point is changed due to the influence of factors such as temperature change, unstable power supply voltage and the like, and is amplified and transmitted step by step, so that the voltage of the output end of the circuit deviates from an original fixed value and floats up and down.
By arranging the null shift processing module, the null shift can be adjusted, signal deviation caused by factors such as temperature change, unstable power supply voltage and the like can be effectively restrained, and the precision of the focusing driving plate is improved.
A capacitor C6 and a resistor R20 are sequentially connected in series between the gate driving end of the NMOSFET group module and the resistor R16.
The common diode D2, the voltage-stabilizing diode D3, the capacitor C6 and the resistor R20 are sequentially connected in series between the drain end and the resistor R16 of the NMOSFET group module, the drain end is connected with the cathode end of the common diode D2, and the anode end of the common diode D2 is connected with the anode end of the voltage-stabilizing diode D3.
A resistor R26, a zener diode D17, a common diode D16, a capacitor C6 and a resistor R20 are sequentially connected in series between the source terminal of the NMOSFET group module and the resistor R16, the resistor R26 is connected with the cathode terminal of the zener diode D17, and the anode terminal of the zener diode D17 is connected with the anode terminal of the common diode D16.
And a common diode D5 is connected between the source terminal and the drain terminal of the NMOSFET group module, the positive terminal of the common diode D5 is connected with the source terminal, and the negative terminal is connected with the drain terminal.
The source electrode end of the NMOSFET group module is also connected with a sampling resistor R2 and a bidirectional transient suppression diode D6 connected with the sampling resistor R2 in parallel, one end of the bidirectional transient suppression diode D6 is connected with the source electrode end, and the other end is grounded.
The grid driving end of the NMOSFET group module is also connected with a common diode D13, an NPN triode T1 and a common diode D14; the positive end of the common diode D13 is connected with the grid driving end, and the negative end of the common diode D is connected with the collector electrode of the NPN triode T1; the positive terminal of the common diode D14 is connected with the emitter of the NPN triode T1, and the negative terminal is grounded; the base electrode of the NPN triode T1 is connected with the source electrode end in series with the resistor R24; a capacitor C7 is connected in parallel between the positive terminal of the common diode D13 and the base electrode of the NPN triode T1.
The source electrode end of the NMOSFET group module is also connected with a common diode D15 and a resistor R25 which are connected in series; the positive terminal of the common diode D15 is connected with the source terminal, and the negative terminal is connected with the resistor R25; the end of the resistor R25 far away from the common diode D15 is connected with a-15V power supply.
The overcurrent protection terminal of the NMOSFET group module is connected to the negative terminal of the common diode D15.
Further, the NMOSFET group module includes four groups of NMOSFET units connected in parallel, which can increase the adjustable range of the focusing current, as shown in fig. 3, and for convenience of description, the four NMOSFET units are sequentially denoted as a first NMOSFET unit, a second NMOSFET unit, a third NMOSFET unit, and a fourth NMOSFET unit.
The first NMOSFET unit comprises a resistor R1A, a resistor R2A, a resistor R3A, NMOSFET, a T1A, NPN type triode T2A, a voltage stabilizing diode D1A and a voltage stabilizing diode D2A; the grid electrode of the NMOSFET tube T1A is connected with a resistor R1A, and one end of the resistor R1A far away from the grid electrode of the NMOSFET tube T1A is marked as X15; the voltage stabilizing diode D1A is connected in parallel between the grid electrode and the source electrode of the NMOSFET T1A, the positive end of the voltage stabilizing diode D1A is connected with the source electrode of the NMOSFET T1A, and the negative end of the voltage stabilizing diode D1A is connected with the grid electrode of the NMOSFET T1A; the voltage stabilizing diode D2A and the resistor R3A are connected in series and then connected with the voltage stabilizing diode D1A in parallel, and the negative electrode end of the voltage stabilizing diode D2A is connected with the negative electrode end of the voltage stabilizing diode D1A; the base electrode of the NPN triode T2A is connected with the positive electrode end of the voltage stabilizing diode D1A, the collector electrode is connected with the negative electrode end of the voltage stabilizing diode D1A, the emitter electrode is connected with the resistor R2A, and one end of the resistor R2A far away from the NPN triode T2A is marked as X13.
The second NMOSFET unit comprises a resistor R1B, a resistor R2B, a resistor R3B, NMOSFET, a T1B, NPN type triode T2B, a voltage stabilizing diode D1B and a voltage stabilizing diode D2B; the grid electrode of the NMOSFET tube T1B is connected with a resistor R1B, and one end of the resistor R1B, which is far away from the grid electrode of the NMOSFET tube T1B, is marked as X1; the voltage stabilizing diode D1B is connected in parallel between the grid electrode and the source electrode of the NMOSFET T1B, the positive end of the voltage stabilizing diode D1B is connected with the source electrode of the NMOSFET T1B, and the negative end of the voltage stabilizing diode D1B is connected with the grid electrode of the NMOSFET T1B; the voltage stabilizing diode D2B and the resistor R3B are connected in series and then connected with the voltage stabilizing diode D1B in parallel, and the negative terminal of the voltage stabilizing diode D2B is connected with the negative terminal of the voltage stabilizing diode D1B; the base electrode of the NPN triode T2B is connected with the positive electrode end of the voltage stabilizing diode D1B, the collector electrode is connected with the negative electrode end of the voltage stabilizing diode D1B, the emitter electrode is connected with the resistor R2B, and one end of the resistor R2B far away from the NPN triode T2B is marked as X3.
The third NMOSFET unit comprises a resistor R1C, a resistor R2C, a resistor R3C, NMOSFET, a T1C, NPN type triode T2C, a voltage stabilizing diode D1C and a voltage stabilizing diode D2C; the grid electrode of the NMOSFET tube T1C is connected with a resistor R1C, and one end of the resistor R1C, which is far away from the grid electrode of the NMOSFET tube T1C, is marked as X16; the voltage stabilizing diode D1C is connected in parallel between the grid electrode and the source electrode of the NMOSFET T1C, the positive end of the voltage stabilizing diode D1C is connected with the source electrode of the NMOSFET T1C, and the negative end of the voltage stabilizing diode D1C is connected with the grid electrode of the NMOSFET T1C; the voltage stabilizing diode D2C and the resistor R3C are connected in series and then connected with the voltage stabilizing diode D1C in parallel, and the negative terminal of the voltage stabilizing diode D2C is connected with the negative terminal of the voltage stabilizing diode D1C; the base electrode of the NPN triode T2C is connected with the positive electrode end of the voltage stabilizing diode D1C, the collector electrode is connected with the negative electrode end of the voltage stabilizing diode D1C, the emitter electrode is connected with the resistor R2C, and one end of the resistor R2C far away from the NPN triode T2C is marked as X14.
The fourth NMOSFET unit comprises a resistor R1D, a resistor R2D, a resistor R3D, NMOSFET, a T1D, NPN type triode T2D, a voltage stabilizing diode D1D and a voltage stabilizing diode D2D; the grid electrode of the NMOSFET tube T1D is connected with a resistor R1D, and one end of the resistor R1D far away from the grid electrode of the NMOSFET tube T1D is marked as X2; the voltage stabilizing diode D1D is connected in parallel between the grid electrode and the source electrode of the NMOSFET T1D, the positive end of the voltage stabilizing diode D1D is connected with the source electrode of the NMOSFET T1D, and the negative end of the voltage stabilizing diode D is connected with the grid electrode of the NMOSFET T1D; the voltage stabilizing diode D2D and the resistor R3D are connected in series and then connected with the voltage stabilizing diode D1D in parallel, and the negative electrode end of the voltage stabilizing diode D2D is connected with the negative electrode end of the voltage stabilizing diode D1D; the base electrode of the NPN triode T2D is connected with the positive electrode end of the voltage stabilizing diode D1D, the collector electrode is connected with the negative electrode end of the voltage stabilizing diode D1D, the emitter electrode is connected with the resistor R2D, and one end of the resistor R2D far away from the NPN triode T2D is marked as X4.
X15, X1, X16 and X2 together form the grid driving end of the NMOSFET group module;
x13, X3, X14 and X4 together form an overcurrent protection end of the NMOSFET group module;
the drain electrode of the NMOSFET tube T1A, the drain electrode of the NMOSFET tube T1B, the drain electrode of the NMOSFET tube T1C and the drain electrode of the NMOSFET tube T1D jointly form a drain electrode end of the NMOSFET group module;
the positive terminal of the zener diode D2A, the positive terminal of the zener diode D2B, the positive terminal of the zener diode D2C, and the positive terminal of the zener diode D2D together form the source terminal of the NMOSFET group module.
Further, the output end of the operational amplifier IC3 is also connected with a resistor R41 and a PNP triode T2; the base of PNP type triode T2 links to each other with resistance R41, and PNP type triode T2's collecting electrode is connected with ground resistance R42, and the projecting pole is connected with photodiode H2, and the positive terminal of photodiode H2 connects +15V power, and the negative terminal links to each other with PNP type triode T2's projecting pole.
Further, a photodiode H1, a resistor R23, a zener diode D12 and a resistor R26 are sequentially connected in series between the positive electrode and the negative electrode of the direct-current voltage source; the positive terminal of the photodiode H1 is connected with the positive electrode of the direct-current voltage source, and the negative terminal of the photodiode H1 is connected with the resistor R23; the positive terminal of the zener diode D12 is connected to the negative electrode of the dc voltage source, and the negative terminal is connected to the resistor R23.
The direct current source input to the drain end of the NMOSFET group module is provided with the photodiode H1 (equivalent to an indicator lamp), and the linear adjustment and feedback module of the NMOSFET group module is provided with the photodiode H2 (equivalent to the indicator lamp), so that the focusing driving plate has a good monitoring function and can be accurately positioned when faults occur.
According to the focusing system for the electron beam welding machine, provided by the embodiment of the application, the size of the focusing current output by the focusing driving plate is regulated by changing the control signal of the system, so that the position of an electron beam focus relative to a workpiece to be welded is regulated, and the requirement of electron beam welding is met; specifically, control signals enter a focusing driving plate from B6 and Z6, reverse voltage signals with almost the same proportion are output after passing through a differential amplification module, the regulated voltage signals are connected into a grid driving end of an NMOSFET group module through a linear regulation and feedback module, focusing current capable of driving a focusing coil is controlled and output, meanwhile, the output current signals are fed back through an operational amplifier IC3 of the linear regulation and feedback module and related circuits, and the input voltage control signals and the output current signals are correspondingly regulated in a linear mode through a potentiometer R15 of the linear regulation and feedback module and a potentiometer R17 of a zero drift processing module, so that stable focusing current with excellent linear variation of 0-5000 mA is finally output.
The principles and embodiments of the present application have been described herein with reference to specific examples, the description of which is intended only to facilitate an understanding of the method of the present application and its core ideas. The foregoing is merely illustrative of the preferred embodiments of this application, and it is noted that there is objectively no limit to the specific structure disclosed herein, since numerous modifications, adaptations and variations can be made by those skilled in the art without departing from the principles of the application, and the above-described features can be combined in any suitable manner; such modifications, variations and combinations, or the direct application of the inventive concepts and aspects to other applications without modification, are contemplated as falling within the scope of the present application.
Claims (5)
1. The focusing system for the electron beam welding machine comprises an electron gun and a focusing coil, and is characterized in that the focusing coil is driven by a focusing driving plate, and a driving circuit of the focusing driving plate comprises a control and regulation module, an NMOSFET group module and a direct-current voltage source;
the NMOSFET group module is provided with a drain terminal, a source terminal, a grid driving terminal and an overcurrent protection terminal; the positive electrode of the direct-current voltage source is connected with the drain terminal, and the negative electrode of the direct-current voltage source is connected with the source terminal; the control and regulation module is connected with the grid driving end and used for controlling the voltage of the grid driving end; the NMOSFET group module generates a focusing current capable of driving the focusing coil between the drain terminal and the source terminal according to a voltage difference between the gate driving terminal and the drain terminal;
the control and regulation module comprises a differential amplification module, a linear regulation and feedback module and a zero drift processing module;
the differential amplification module is configured to receive a control signal; the control signal is an adjustable direct-current voltage signal with the voltage of 0-10V; the control signal passes through the differential amplification module and then outputs a reverse voltage signal with the same proportion;
the linear regulation and feedback module is configured to perform linear feedback regulation on the voltage signal of the gate driving end introduced into the NMOSFET group module; the linear regulation and feedback module takes the voltage signal output by the differential amplification module as an input signal and takes the voltage signal output by the source electrode end of the NMOSFET group module as a feedback signal;
the zero drift processing module is configured to adjust the zero drift of the circuit;
the differential amplification module includes: resistor R3, resistor R4, resistor R5, ground capacitor C3, ground capacitor C4, ground capacitor C13, ground capacitor C14, diode D7, diode D8, diode D9, diode D10, and differential amplifier IC1;
the positive end of the control signal is connected with the resistor R3 in series and then connected to the reverse input end of the differential amplifier IC1, and the negative end of the control signal is connected with the resistor R4 in series and then connected to the positive input end of the differential amplifier IC1;
the reverse input end of the differential amplifier IC1 is also connected with the grounding capacitor C3, and the positive input end of the differential amplifier IC1 is also connected with the grounding capacitor C4; the resistor R5 is also connected between the positive input end and the negative input end of the differential amplifier IC1;
the reverse input end of the differential amplifier IC1 is also connected with the negative electrode of the diode D8, and the positive electrode of the diode D8 is connected with-15V voltage; the reverse input end of the differential amplifier IC1 is also connected with the positive electrode of the diode D7, and the negative electrode of the diode D7 is connected with +15V voltage;
the positive input end of the differential amplifier IC1 is also connected with the negative electrode of the diode D10, and the positive electrode of the diode D10 is connected with-15V voltage; the positive input end of the differential amplifier IC1 is also connected with the positive electrode of the diode D9, and the negative electrode of the diode D9 is connected with +15V voltage;
the positive power supply voltage end of the differential amplifier IC1 is connected with +15V voltage and is also connected with the grounding capacitor C13; the negative power supply voltage end of the differential amplifier IC1 is connected with-15V voltage and is also connected with the grounding capacitor C14; the reference terminal of the differential amplifier IC1 is grounded;
the linear regulation and feedback module comprises an operational amplifier IC3; the source electrode end is connected with the reverse input end of the operational amplifier IC3 in series with a resistor R19; the positive input end of the operational amplifier IC3 is grounded; the positive power supply voltage end of the operational amplifier IC3 is connected with +15V voltage and is also connected with a grounding capacitor C17; the negative power supply voltage end of the operational amplifier IC3 is connected with-15V voltage and is also connected with a grounding capacitor C18; the output end of the operational amplifier IC3 is connected with a common diode D11, a resistor R22 and a resistor R21 which are sequentially connected in series; the negative end of the common diode D11 is connected with the output end of the operational amplifier IC3, and the positive end of the common diode D is connected with the resistor R22; one end of the resistor R21 far away from the resistor R22 is connected with a +15V power supply; one end of the resistor R22 far away from the common diode D11 is connected with a capacitor C6; one end of the capacitor C6 far away from the resistor R22 is connected with a resistor R20; one end of the resistor R20 far away from the resistor R22 is connected with a resistor R16; the resistor R16 is also connected to the inverting input of the operational amplifier IC3; one end of the resistor R16, which is far away from the reverse input end of the operational amplifier IC3, is connected with a potentiometer R15; one end of the potentiometer R15 far away from the resistor R16 is connected with the output end of the differential amplifier IC1;
the zero-drift treatment module comprises: a potentiometer R17 and a resistor R18; the two ends of the potentiometer R17 are respectively connected with +15V voltage and-15V voltage, the adjusting end of the potentiometer R17 is connected with the resistor R18, and the other end of the resistor R18 is connected with one end of the resistor R16 far away from the potentiometer R15.
2. The focusing system for an electron beam welder of claim 1, wherein the NMOSFET group module comprises four groups of NMOSFET cells of identical structure connected in parallel; the NMOSFET cell includes: the first resistor, the second resistor, the third resistor, the first NMOSFET, the first NPN triode, the first zener diode and the second zener diode;
the grid electrode of the first NMOSFET is connected with the first resistor, and one end, far away from the grid electrode of the first NMOSFET, of the first resistor forms a grid electrode driving end of the NMOSFET group module;
the first voltage stabilizing diode is connected in parallel between the grid electrode and the source electrode of the first NMOSFET, the positive electrode end of the first voltage stabilizing diode is connected with the source electrode of the first NMOSFET, and the negative electrode end of the first voltage stabilizing diode is connected with the grid electrode of the first NMOSFET; the second zener diode and the third resistor are connected in series and then connected with the first zener diode in parallel, and the cathode end of the second zener diode is connected with the cathode end of the first zener diode; the base electrode of the first NPN triode is connected with the positive electrode end of the first voltage stabilizing diode, the collector electrode of the first NPN triode is connected with the negative electrode end of the first voltage stabilizing diode, the emitter electrode of the first NPN triode is connected with the second resistor, and one end, far away from the first NPN triode, of the second resistor forms an overcurrent protection end of the NMOSFET group module.
3. The focusing system for an electron beam welder according to claim 1, wherein a gate drive end of the NMOSFET group module is connected to an end of the capacitor C6 remote from the resistor R20;
a common diode D2, a zener diode D3, the capacitor C6 and the resistor R20 are sequentially connected in series between the drain terminal of the NMOSFET group module and the resistor R16;
a resistor R26, a zener diode D17, a common diode D16, the capacitor C6 and the resistor R20 are sequentially connected in series between the source terminal of the NMOSFET group module and the resistor R16;
a common diode D5 is connected between the source terminal and the drain terminal of the NMOSFET group module, the positive terminal of the common diode D5 is connected with the source terminal, and the negative terminal is connected with the drain terminal;
the source electrode end of the NMOSFET group module is also connected with a sampling resistor R2 and a bidirectional transient suppression diode D6 connected with the sampling resistor R2 in parallel, one end of the bidirectional transient suppression diode D6 is connected with the source electrode end, and the other end is grounded;
the grid driving end of the NMOSFET group module is also connected with a common diode D13, an NPN triode T1 and a common diode D14; the positive end of the common diode D13 is connected with the grid driving end, and the negative end of the common diode D is connected with the collector electrode of the NPN triode T1; the positive terminal of the common diode D14 is connected with the emitter of the NPN triode T1, and the negative terminal is grounded; the base electrode of the NPN triode T1 is connected with the source electrode end in series with the resistor R24; a capacitor C7 is connected in parallel between the positive electrode end of the common diode D13 and the base electrode of the NPN triode T1;
the source electrode end of the NMOSFET group module is also connected with a common diode D15 and a resistor R25 which are connected in series; the positive terminal of the common diode D15 is connected with the source terminal, and the negative terminal of the common diode D is connected with the resistor R25; one end of the resistor R25 far away from the common diode D15 is connected with a-15V power supply;
the overcurrent protection terminal of the NMOSFET group module is connected to the negative terminal of the common diode D15.
4. The focusing system for electron beam welding machine according to claim 3, wherein the output end of the operational amplifier IC3 is further connected with a resistor R41 and a PNP transistor T2; the base electrode of the PNP triode T2 is connected with the resistor R41, the collector electrode is connected with the grounding resistor R42, and the emitter electrode is connected with the photodiode H2; the positive electrode of the photodiode H2 is connected with a +15V power supply, and the negative electrode of the photodiode H2 is connected with the emitter of the PNP triode T2.
5. The focusing system for an electron beam welding machine according to claim 4, wherein a photodiode H1, a resistor R23, and a zener diode D12 are further connected in series in this order between the positive electrode and the negative electrode of the dc voltage source; the positive end of the photodiode H1 is connected with the positive electrode of the direct-current voltage source, and the negative end of the photodiode H1 is connected with the resistor R23; the positive terminal of the zener diode D12 is connected to the negative electrode of the dc voltage source, and the negative terminal is connected to the resistor R23.
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