High-voltage power supply circuit with extremely low electron beam current fluctuation, electron beam welding machine and equipment

Abstract

The invention discloses a high-voltage power supply circuit with extremely low electron beam current fluctuation, an electron beam welding machine and equipment. The high-voltage power supply circuit comprises a high-voltage power supply, a bias power supply, a filament power supply, resistors R1-R3 and a capacitor C1, the negative electrode of the high-voltage power supply is connected with the negative electrode of the bias power supply after passing through the resistor R3, the positive electrode of the bias power supply is connected with the positive electrode and the negative electrode of the filament power supply after passing through the resistor R1 and the resistor R2, and the capacitor C1 is connected to the two ends of the bias power supply in parallel; according to the invention, the decoupling of the high-voltage power supply ripple and the bias voltage of the electron gun is realized, so that the beam fluctuation of the high-voltage electron beam welding machine is reduced from the general level of 2-4% to the lt; and therefore, extremely low beam fluctuation is realized. The technology is not only applied to the field of high-voltage electron beam welding machines, but also has wide application prospects in the fields of electron beam additive manufacturing, accelerator physical electron beam equipment and the like.

Description

Technical Field

[0001] This invention relates to the field of electron beam technology, and more particularly to high-voltage power supply circuits with extremely low electron beam current fluctuations, electron beam welding machines and equipment. Background Art

[0002] The power supply system of a high-voltage electron beam welder consists of three power supplies: a high-voltage power supply, a bias power supply, and a filament power supply. The high-voltage power supply outputs a negative high voltage to accelerate the electron beam. The bias power supply provides a negative bias voltage to the grid to suppress electron output and regulate the beam current. The filament power supply outputs a current of several to tens of amperes to heat the filament and generate electrons. The welding principle of the electron beam welder is as follows: the filament power supply outputs current to heat the filament, causing it to emit electrons. An electron cloud forms within the bias cup. Under the control of the electric field provided by the bias power supply, the electrons are accelerated by the high-voltage electric field generated by the high-voltage power supply and bombard the workpiece. A large amount of the electron beam's kinetic energy is converted into heat energy, melting the workpiece at the bombardment location to form a molten pool, thus achieving welding. During the welding process, a negative bias voltage (bias power supply) is also applied between the electron gun cathode and the bias cup (grid). The magnitude of the electron beam current is controlled and adjusted by adjusting the magnitude of the negative bias voltage.

[0003] The high-voltage circuit and ripple coupling path schematics of high-voltage electron beam welding machines at home and abroad are as follows: Figure 1 and Figure 2 As shown, the high-voltage ripple passes through the current-limiting resistor R3 and is coupled to ground via capacitors C1 and C3. The high-voltage ripple is divided by capacitors C1 and C3, with the high-voltage ripple on C3 going directly to ground. The high-voltage ripple on C1 is filtered by resistors R1 / / R2 and capacitor C2 and then coupled to the bias cup. Therefore, the voltage fluctuation of the bias power supply is closely related to the high-voltage power supply ripple. The high-voltage power supply ripple will be superimposed on the bias power supply, thus affecting the beam current fluctuation (peak-to-peak value 2%-4%), which does not meet the requirement of less than 0.3% for beam current fluctuation in high-end manufacturing fields. Summary of the Invention

[0004] The main objective of this invention is to provide a high-voltage power supply circuit, an electron beam welder and equipment with extremely low electron beam current fluctuations, in order to solve existing technical problems.

[0005] To achieve the above objectives, the present invention provides a high-voltage power supply circuit with extremely low electron beam current fluctuations, including a high-voltage power supply, a bias power supply, a filament power supply, resistors R1-R3 and capacitor C1. The negative terminal of the high-voltage power supply is connected to the negative terminal of the bias power supply via resistor R3. The positive terminal of the bias power supply is connected to the positive and negative terminals of the filament power supply via resistors R1 and R2. The capacitor C1 is connected in parallel across the two ends of the bias power supply.

[0006] Furthermore, the resistor R3 is a current-limiting resistor.

[0007] Electron beam welding machines, including An electron gun consists of a cathode, a bias cup, and an anode; Such as the high-voltage power supply circuit with extremely low electron beam current fluctuations mentioned above. The negative terminal of the bias power supply is connected to the bias cup via a coaxial cable; the cathode of the electron gun is connected to both ends of the filament power supply via a coaxial cable; and the positive terminal of the high-voltage power supply is connected to the anode of the electron gun and the ground via coaxial cables.

[0008] Furthermore, a junction capacitance C2 is provided between the coaxial cable filament and the bias voltage; Furthermore, a junction capacitance C3 is provided between the coaxial cable bias and the outermost shielding layer.

[0009] An electronic device comprising a high-voltage power supply circuit with extremely low electron beam current fluctuations as described above.

[0010] The beneficial effects of this invention are reflected in: This invention decouples the high-voltage power supply ripple from the electron gun bias voltage, reducing the beam current fluctuation of high-voltage electron beam welders from the typical level of 2%-4% to <0.2%, achieving extremely low beam current fluctuation. This technology is not only applied in the field of high-voltage electron beam welders, but also has broad application prospects in electron beam additive manufacturing, accelerator physics electron beam equipment, and other fields. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the power supply circuit of an existing electron beam welding machine; Figure 2 This is a schematic diagram of the existing high-voltage power supply ripple coupling path; Figure 3 This is a schematic diagram of the high-voltage power supply circuit with extremely low electron beam current fluctuation of the present invention. Figure 4 This is a schematic diagram of the high-voltage power supply ripple coupling path of the present invention. Detailed Implementation

[0012] 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 a part of the embodiments of the present invention, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. 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.

[0013] This invention uses a high-voltage electron beam welding machine as an example for illustration. The principle block diagram of the power supply system of an existing high-voltage electron beam welding machine is as follows: Figure 1 As shown; The novel circuit topology of the high-voltage electron beam welding machine power supply of this invention is as follows: Figure 3 As shown, it mainly consists of a power supply system, a triaxial cable and an electron gun. The power supply system consists of a high voltage power supply, a bias power supply, a filament power supply, resistors R1~R3 ​​and capacitor C1, and the electron gun consists of a cathode, a bias cup and an anode. The connection is as follows: the negative terminal of the high-voltage power supply is connected to the negative terminal of the bias power supply after passing through the current-limiting resistor R3; the positive terminal of the bias power supply is connected to the positive and negative terminals of the filament power supply after passing through resistors R1 and R2; the negative terminal of the bias power supply is connected to the bias cup; the cathode of the electron gun is connected to both ends of the filament power supply; capacitor C1 is connected in parallel across both ends of the bias power supply; the positive terminal of the high-voltage power supply is connected to the anode of the electron gun and ground respectively; C2 is the junction capacitance between the coaxial cable filament and the bias voltage; C3 is the junction capacitance between the coaxial cable bias voltage and the outermost shielding layer (ground).

[0014] The negative terminal of the bias power supply is suspended above the negative terminal of the high-voltage power supply (-150kV), and both terminals of the filament power supply are suspended above the positive terminal of the bias power supply. This creates a multi-point suspension operating mode between the filament power supply, the bias power supply, and the high-voltage power supply. During operation, when the high-voltage power supply outputs a negative DC voltage, it will be accompanied by high-voltage ripple (AC). The schematic diagram of the high-voltage ripple coupling path is shown below. Figure 4 .

[0015] The high-voltage ripple output from the high-voltage power supply, after passing through the current-limiting resistor R3, will not be coupled to the bias power supply via capacitor C1 and resistors R1 / / R2. Instead, it will be directly coupled to ground via capacitor C3 through the shortest path, thus decoupling the high-voltage ripple from the bias power supply output voltage. Therefore, the high-voltage ripple output from the high-voltage power supply will not be superimposed on the bias power supply and will not affect the beam current fluctuation, thereby reducing the working beam current fluctuation during electron gun welding.

[0016] This invention also provides an electronic device, including the extremely high electron beam current controllable power supply system described above. This electronic device can be used in fields such as microfocus X-ray sources, electron beam welding in high-end manufacturing, large accelerators such as fourth-generation light sources, and high-end radiation equipment for nuclear medicine.

[0017] It should be noted that if the embodiments of the present invention involve directional indicators such as up, down, left, right, front, back, etc., the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture as shown in the attached figure. If the specific posture changes, the directional indicators will also change accordingly.

[0018] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied. Furthermore, "multiple" refers to two or more. Moreover, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent.

[0019] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high-voltage power supply circuit with extremely low electron beam current fluctuations, characterized in that: This includes a high-voltage power supply, a bias power supply, a filament power supply, resistors R1-R3, and capacitor C1; The negative terminal of the high-voltage power supply is connected to the negative terminal of the bias power supply via resistor R3. The positive terminal of the bias power supply is connected to the positive and negative terminals of the filament power supply via resistors R1 and R2. The capacitor C1 is connected in parallel across the two ends of the bias power supply.

2. The high-voltage power supply circuit with extremely low electron beam current fluctuation as described in claim 1, characterized in that: The resistor R3 is a current-limiting resistor.

3. An electron beam welding machine, characterized in that: include, An electron gun consists of a cathode, a bias cup, and an anode; The high-voltage power supply circuit with extremely low electron beam current fluctuation as described in any one of claims 1-2; The negative terminal of the bias power supply is connected to the bias cup via a coaxial cable; the cathode of the electron gun is connected to both ends of the filament power supply via a coaxial cable; and the positive terminal of the high-voltage power supply is connected to the anode of the electron gun and the ground via coaxial cables.

4. The electron beam welding machine as described in claim 3, characterized in that: A junction capacitance C2 is provided between the filament of the coaxial cable and the bias voltage.

5. The electron beam welding machine as described in claim 3, characterized in that: A junction capacitance C3 is provided between the bias voltage of the coaxial cable and the outermost shielding layer.

6. An electronic device, characterized in that: Including the high-voltage power supply circuit with extremely low electron beam fluctuation as described in claims 1-2.

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