A filament bundle coaxial thermionic cathode electron beam fuse additive manufacturing and repair apparatus

Abstract

This invention relates to the technical field of fused wire additive manufacturing and repair, and mainly discloses a fused wire additive manufacturing and repair device for coaxial hot cathode electron beam fused wire, which includes a lens assembly, including a first lens and a second lens fixed at the bottom center of the first lens. An emission area is formed between the first lens and the second lens, and a filament assembly is disposed in the emission area. The first lens has a constraint surface on the contact side with the emission area, and the second lens has an emission gap. The electron beam formed in the emission area is adjusted by the constraint surface and passes through the emission gap, focusing on the filament. This invention overcomes the problems of existing cold cathode electron beams relying on gas discharge, beam current being affected by cavity gas pressure fluctuations, and the uniformity of the annular beam being greatly affected by plasma density. The generation and focusing of electrons require precise coordination of gas content, type, and operating voltage in the electron gun, which is difficult to achieve.

Description

Technical Field

[0001] This invention relates to the technical field of fused wire additive manufacturing and repair, and in particular to a fused wire additive manufacturing and repair apparatus for coaxial hot cathode electron beam fused wire. Background Technology

[0002] Currently, fused wire additive manufacturing and repair technologies are developing rapidly. Electron beam heat sources have great advantages in fused wire additive manufacturing and repair of highly reflective materials, refractory materials, and easily oxidized materials due to their high and controllable energy density, high cladding efficiency, no pollution or oxidation under vacuum conditions, and no reflection compared to laser heat sources.

[0003] Electron beam fused wire additive manufacturing and repair currently includes two modes: cold cathode coaxial wire feeding and hot cathode off-axis wire feeding. Off-axis wire feeding has disadvantages such as unstable wire bundle coordination, additive path being limited by the relative position of the wire bundle, and difficulty in forming complex shapes.

[0004] Fused wire additive manufacturing technology using coaxial cold cathode electron beams offers advantages such as stable wire assembly and the ability to form complex shapes. However, cold cathode electron beams rely on gas discharge, and the beam current is affected by fluctuations in cavity gas pressure. The uniformity of the annular beam is greatly affected by plasma density. Electron generation and focusing require precise matching of gas content, type, and operating voltage within the electron gun, which is challenging to achieve. Furthermore, it suffers from the lack of independent focusing adjustment parameters. Therefore, it is suitable for low-precision coaxial fused wire additive manufacturing. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is that: existing cold cathode electron beams rely on gas discharge, the beam current is affected by the fluctuation of the cavity gas pressure, the uniformity of the ring beam is greatly affected by the plasma density, and the generation and focusing of electrons require precise coordination of the gas content, type and working voltage in the electron gun, which is difficult to achieve.

[0006] The above-mentioned technical problems are solved by the following technical solution: The present invention proposes a filament bundle coaxial hot cathode electron beam filament additive manufacturing and repair device, which includes a lens assembly, including a first lens and a second lens fixed at the bottom center of the first lens. An emission area is formed between the first lens and the second lens, and a filament assembly is disposed in the emission area. The first lens has a constraint surface on the contact side with the emission area, and an emission gap is opened on the second lens. The electron beam formed in the emission area passes through the emission gap after being adjusted by the constraint surface and is focused on the filament.

[0007] In a preferred embodiment of the coaxial hot cathode electron beam fused wire additive manufacturing and repair apparatus of the present invention: the first lens includes a first lens segment and a second lens segment fixed at an angle to it, the angle facing the emission area, and the constraint surface is a concave surface enclosed by the angle; wherein, both the first lens segment and the second lens segment are annular structures.

[0008] In a preferred embodiment of the coaxial hot cathode electron beam fused wire additive manufacturing and repair apparatus of the present invention: the second lens includes a first arc mirror and a second arc mirror that do not contact each other, the inner arc surfaces of the first arc mirror and the second arc mirror face the wire, and the outer arc surfaces contact the emission area; the gap between the first arc mirror and the second arc mirror is the emission gap.

[0009] In a preferred embodiment of the coaxial hot cathode electron beam filament additive manufacturing and repair device of the present invention: the filament assembly includes a retainer, a filament body and a terminal block, wherein the retainer is fixed to the filament body.

[0010] In a preferred embodiment of the coaxial hot cathode electron beam filament additive manufacturing and repair device of the present invention: the filament body is a single ring structure, and the terminal block is vertically fixed at both ends of the single filament body.

[0011] In a preferred embodiment of the coaxial hot cathode electron beam filament additive manufacturing and repair device of the present invention: the filament body includes several groups of arc-shaped rings distributed in a ring, each group of arc-shaped rings is fixed with at least one fixture, and both ends of the arc-shaped rings are vertically fixed with terminals.

[0012] In a preferred embodiment of the coaxial hot cathode electron beam fused wire additive manufacturing and repair device of the present invention: the radial cross section of the filament body has a regular geometric shape with symmetrical distribution.

[0013] In a preferred embodiment of the coaxial hot cathode electron beam fused wire additive manufacturing and repair device of the present invention: it further includes a base and an anode assembly, the anode assembly including an inner anode and an outer anode, both the inner anode and the outer anode being fixed to the middle of the bottom end of the base, and the inner anode being disposed inside the outer anode; the first lens is coaxially disposed between the inner anode and the outer anode, the base is provided with a mounting hole, and the terminal block passes through the mounting hole and extends to the top of the base.

[0014] In a preferred embodiment of the coaxial hot cathode electron beam fused wire additive manufacturing and repair device of the present invention: a perforation is provided on the first lens segment, and the retainer is fitted through the perforation and fixed to the bottom end of the base; a plurality of connecting sleeves are also fixed at the top end of the first lens, and the connecting sleeves connect and fix the first lens to the base.

[0015] In a preferred embodiment of the coaxial hot cathode electron beam fused wire additive manufacturing and repair device of the present invention: a wire feeding hole is provided in the middle of the base, a wire feeding channel is provided in the middle of the inner anode, and the inner anode is fixed to the first arc mirror through an expanding ring; the outer anode includes a vertical ring segment fixed perpendicularly to the base, and a sealing ring segment is also vertically fixed at the bottom end of the vertical ring segment, and an annular hole is provided in the middle of the sealing ring segment, and the second arc mirror is fixed to the wall of the annular hole.

[0016] The beneficial effects of this invention are as follows:

[0017] This invention relates to a coaxial hot cathode electron beam fused wire additive manufacturing and repair device, which breaks through the structural bottleneck of the hot cathode and the wire bundle being coaxial, and realizes the technological innovation of coaxial wire feeding of the hot cathode electron beam.

[0018] The device utilizes a double-focusing mechanism of an angled concave constraint surface and an arc-shaped lens, along with an electrostatic lens system composed of inner and outer anodes. This allows for independent adjustment of the voltage of the first lens, which serves as the grid, thereby controlling the beam size, position, and focal point. The adjustment is convenient and highly precise. The annular filament structure acts as the cathode, forming a 360° annular electron beam that heats the filament without any dead angles, avoiding asymmetric melting and significantly improving the uniformity of the filament and energy utilization.

[0019] The hot cathode thermal emission eliminates the need for gas discharge, preventing gas pollution and extending cathode lifespan. The beam current is controlled by both the filament current and the grid, significantly improving stability. The device features a coaxial layout, freeing the additive manufacturing path from filament position limitations. This enables high-precision, high-purity forming of complex shapes and is suitable for additive manufacturing and repair of highly reactive, refractory, and easily oxidized materials in vacuum environments, combining practicality and adaptability. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Wherein: Figure 1 A schematic diagram showing the distribution of the lens assembly and filament assembly is provided.

[0021] Figure 2 A schematic diagram of the first lens is shown.

[0022] Figure 3 A schematic diagram of the second lens is shown.

[0023] Figure 4 A schematic diagram of the filament assembly is shown.

[0024] Figure 5 Another schematic diagram of the filament assembly is shown.

[0025] Figure 6 A schematic diagram of the cross-sectional shape of the filament body is shown.

[0026] Figure 7 A schematic diagram of the overall assembly of the base and anode assembly is shown.

[0027] Figure 8 A partial assembly diagram of a wire bundle coaxial hot cathode electron beam fused wire additive manufacturing and repair device is shown.

[0028] Figure 9 A schematic diagram showing the assembly details of the second lens and the anode assembly is provided.

[0029] Figure 10 The diagram shows the electric field potential energy simulation analysis of the coaxial hot cathode electron beam fused wire additive manufacturing and repair device.

[0030] Figure 11 The diagram shows the electron beam trajectory and energy simulation analysis from a first-person perspective of a wire bundle coaxial hot cathode electron beam fused wire additive manufacturing and repair device.

[0031] Figure 12 The diagram shows the electron beam trajectory and energy simulation analysis from a second-view perspective of the coaxial hot cathode electron beam fused wire additive manufacturing and repair device.

[0032] Figure 13 A schematic diagram of the working state of an electron beam focused on a filament is shown.

[0033] Figure 14 The diagram shows the actual variation in the size of the spot on the filament by adjusting the gate voltage. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0035] The terminology used in this invention is that which is currently widely used in the art in consideration of the function of the invention; however, these terms may vary according to the intent of those skilled in the art, precedent, or new technology in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the invention. Therefore, the terms used in this specification should not be construed as simple names, but rather based on their meanings and the overall description of the invention.

[0036] Reference Figures 1 to 14This embodiment provides a filament bundle coaxial hot cathode electron beam fused wire additive manufacturing and repair device, which includes a lens assembly 100, including a first lens 101 and a second lens 102 fixed to the middle of the bottom end of the first lens 101. An emission area A is formed between the first lens 101 and the second lens 102, and a filament assembly 200 is disposed in the emission area A.

[0037] The emission zone A is the core cavity for thermionic electron thermal emission, which is compatible with the layout structure of the filament assembly 200. It provides a stable spatial environment for the generation of electron beams and can be adapted to various working conditions such as ground vacuum chambers and space vacuum. It is the core spatial foundation for realizing the coaxial cooperation between electron beam and filament bundle.

[0038] The entire device needs to be placed in a vacuum chamber, and a vacuum environment maintenance device consisting of a vacuum pump and vacuum detection instruments is used to provide a stable vacuum working environment for the entire device, so as to avoid the influence of air on electron beam transmission, filament thermal emission and filament melting, and ensure stable operation of the device.

[0039] The first lens 101 has a constraint surface B on the side in contact with the emission area A, and the second lens 102 has an emission gap C. The electron beam formed in the emission area A is adjusted by the constraint surface B and passes through the emission gap C, focusing on the filament. After being constrained and guided, the electron beam forms a uniform annular beam, which can achieve 360° heating of the filament conveyed in the center without dead angles. This avoids the asymmetric melting problem caused by the single-sided heating shadow of traditional off-axis wire feeding, and effectively improves the forming accuracy and quality of fused wire additive manufacturing and repair.

[0040] The conveying of the filament is accomplished by a filament conveying device consisting of a filament reel, a filament feeding motor, a filament feeding guide tube, and a tension adjustment mechanism. The filament feeding motor works in coordination with the filament feeding hole 303 of the subsequent base 300 and the filament feeding channel 401a of the inner anode 401 to achieve uniform and precise conveying of the filament. The tension adjustment mechanism can prevent loosening or breakage of the filament during the conveying process and ensure the stability of the filament conveying.

[0041] Specifically, the first lens 101 serves as the gate of this device, including a first lens segment 101a and a second lens segment 101b fixed at an angle to it, with the angle facing the emission area A. The constraint surface B is a concave surface enclosed by the angle. This concave constraint surface can laterally limit and guide the electrons emitted by the filament assembly 200 in the emission area A, effectively suppressing the initial dissipation of electrons and ensuring that the electrons move along the preset trajectory to the emission gap C, laying the foundation for the subsequent focusing of the electron beam.

[0042] The first lens segment 101a and the second lens segment 101b are both annular structures, which match the coaxial wire feeding and coaxial electron beam emission structure of the whole device, so that the constraint surface B forms an annular electron beam constraint space, ensuring the formation basis of the annular electron beam. At the same time, they are adapted to the annular structure of the inner anode 401 and the outer anode 402, realizing the coaxial assembly of the lens assembly 100 and the anode assembly 400.

[0043] Furthermore, the second lens 102 includes a first arc mirror 102a and a second arc mirror 102b that do not contact each other. The inner arc surfaces of the first arc mirror 102a and the second arc mirror 102b face the wire, and the outer arc surfaces contact the emission area A. The arc structure is highly consistent with the trajectory of the electrons, which can perform secondary focusing calibration on the electron beam initially guided by the constraint surface B, further improving the concentration and uniformity of the electron beam, avoiding the dissipation of the electron beam during transmission, and ensuring the effective utilization of the electron beam energy. The energy distribution of the electron beam can be monitored in real time by the electron beam energy monitor in the monitoring device, which facilitates timely adjustment of relevant parameters and ensures the electron beam focusing effect.

[0044] The gap between the first arc mirror 102a and the second arc mirror 102b is the emission gap C, which is the only emission channel for the annular electron beam. Its size and position are precisely designed to meet the transmission requirements of the annular electron beam, ensuring that the electron beam can be accurately focused on the central filament after emission, so that almost all of the beam current acts on the filament, greatly improving the energy utilization rate and solving the problem of serious energy loss in traditional devices. The melting state of the filament can be observed in real time by the filament melting state camera in the monitoring device, so as to detect melting abnormalities in time and adjust parameters.

[0045] The filament assembly 200 includes a retainer 201, a filament body 202, and a terminal block 203. The retainer 201 is fixed to the filament body 202. The retainer 201 is made of tantalum metal or insulating high-temperature resistant ceramic material. In this embodiment, tantalum metal is preferred because it is less prone to breakage than ceramic material. As the core fixing structure of the filament body 202, it can stably arrange the filament body 202 in the emission area A, ensuring that the filament body 202 is concentric with the central axis of the device, avoiding uneven electron beam emission due to filament misalignment. At the same time, it realizes a rigid connection between the filament body 202 and the lens assembly 100 and the base 300, isolates the filament body 202 from other metal parts, prevents short circuits, and adapts to the high-temperature working requirements in a vacuum environment.

[0046] In this embodiment, in order to improve the service life of the filament assembly 200 and the overall stability of the device, the filament assembly 200 can be equipped with a cooling device for heat dissipation, so as to avoid the filament burning due to long-term high temperature operation and extend the service life of the filament. At the same time, the filament body 202 is made of high temperature resistant metal materials such as tantalum wire, tungsten wire, molybdenum wire or niobium wire, which can withstand the thermionic emission conditions in a vacuum environment and reduce the frequency of maintenance and replacement.

[0047] The filament body 202 is the cathode of this device and can be configured as a single ring structure. The terminal block 203 is vertically fixed at both ends of the single filament body 202 to form a continuous electron emission surface, ensuring the circumferential uniformity of the electron beam. It is integrally formed with the filament body 202, with a firm connection and excellent conductivity, providing a stable power supply path for the filament body 202 and realizing the precise input and adjustment of the filament current.

[0048] The filament body 202 can also be configured to include several groups of arc-shaped rings 202a arranged in a ring shape. Each group of arc-shaped rings 202a is arranged at equal intervals in the circumferential direction along the central axis of the device to form a spliced ​​electron emission structure. The electron emission density can be flexibly adjusted according to actual processing requirements. Each group of arc-shaped rings 202a is fixed with at least one fixture 201. The stability of the arrangement is improved by fixing at multiple points. Both ends of the arc-shaped rings 202a are vertically fixed with terminals 203, which can realize independent power supply and start / stop of a single group of arc-shaped rings 202a, improving the flexibility of electron beam control.

[0049] Furthermore, the radial cross-section of the filament body 202 is a regular geometric shape with symmetrical distribution. Specifically, it can be a circle, a semi-circle, an ellipse, or a regular n-gon (n>2, where n is a natural number). The symmetrical cross-sectional structure ensures that the heat distribution is uniform when the filament body 202 is energized, avoiding filament burnout caused by local overheating. At the same time, it ensures that the electron emission intensity in the circumferential direction of the filament is consistent, further improving the uniformity of the annular electron beam.

[0050] Furthermore, the device also includes a base 300 and an anode assembly 400. The anode assembly 400 includes an inner anode 401 and an outer anode 402. Both the inner anode 401 and the outer anode 402 are fixed to the middle of the bottom end of the base 300, and the inner anode 401 is disposed inside the outer anode 402. The inner anode 401 and the outer anode 402 are coaxially fitted to form an electrostatic lens system that integrates electron acceleration and focusing, providing an electric field basis for the acceleration and focusing of the electron beam.

[0051] In this embodiment, the anode component 400 is always grounded during use, with a voltage of 0V. During use, the distribution of electric field lines can be adjusted by independently regulating the voltage of the first lens 101, which serves as the gate, thereby changing the trajectory of electrons and achieving independent and precise adjustment of the beam size, position, and focusing position without recalculating various electrical and structural parameters.

[0052] In this embodiment, in order to improve the service life of the anode assembly 400 and the overall stability of the device, the anode assembly 400 can be connected to the cooling water pipeline of the cooling device for heat dissipation, so as to avoid the components being damaged by overheating due to long-term high-voltage operation. At the same time, a high-voltage power supply module is connected to provide it with a stable high-voltage power supply. The high-voltage power supply module, together with the filament current adjustment module, PLC controller and touch operation panel, form a power supply and control system, which can realize real-time monitoring and adjustment of electron beam related parameters and device working status.

[0053] Specifically, the first lens 101 is coaxially positioned between the inner anode 401 and the outer anode 402. The base 300 has a mounting hole 301, and the terminal 203 passes through the mounting hole 301 and extends to the top of the base 300. This coaxial assembly layout ensures that the lens assembly 100 and the anode assembly 400 are aligned with the central axis of the device, ensuring that the trajectory of the electron beam does not deviate during acceleration and focusing. The terminal 203 extends to the top of the base 300, facilitating the connection of an external power supply line and enabling convenient external adjustment of the filament current, thus improving operational convenience and meeting the overall integrated design requirements of the device.

[0054] A perforation 101a-1 is provided on the first lens segment 101a. The fixture 201 passes through the perforation 101a-1 and is fixed to the bottom of the base 300. The size of the perforation 101a-1 is adapted to the fixture 201. Through the cooperation of the perforation 101a-1 and the fixture 201, the filament assembly 200 is double-fixed with the lens assembly 100 and the base 300. This further improves the stability and coaxiality of the filament body 202 in the emission area A, ensures that the electron emission surface is consistent with the electric field center of the electrostatic lens system, ensures the effectiveness of electron beam acceleration and focusing, and avoids the impact of assembly deviation on the working performance of the device.

[0055] The top of the first lens 101 is also fixed with several sets of connecting sleeves 302. The connecting sleeves 302 connect and fix the first lens 101 and the base 300. The connecting sleeves 302 are evenly distributed along the circumference of the first lens 101, and the number is preferably 3 to 4 sets. This achieves rigid fixation between the first lens 101 and the base 300, ensures the coaxiality of the lens assembly 100 as a whole, avoids the positional displacement of the lens assembly 100 due to assembly gaps or vibrations under working conditions, thereby preventing electron beam trajectory deviation, ensuring the accuracy of electron beam constraint and focusing, and improving the stability of the device operation.

[0056] Furthermore, a wire feeding hole 303 is provided in the middle of the base 300, and a wire feeding channel 401a is provided in the middle of the inner anode 401. The wire feeding hole 303 and the wire feeding channel 401a are coaxially connected to form an axial conveying channel for the wire. In coordination with the wire conveying device, the wire is conveyed at a constant speed along the central axis of the device to the electron beam focusing area, ensuring that the wire is always in the center of the annular electron beam and achieving uniform melting of the wire by the electron beam.

[0057] The inner anode 401 is fixed to the first arc mirror 102a through the expansion ring 401b. The expansion ring 401b is a conductive metal structure, which not only realizes the rigid connection between the inner anode 401 and the second lens 102, ensuring the coaxial assembly accuracy of the two, but also realizes the continuous conduction of the electric field, ensuring the effect of secondary electron beam focusing and ensuring the accuracy of electron beam focusing.

[0058] The external anode 402 includes a vertical ring segment 402a that is vertically fixed to the base 300. A sealing ring segment 402b is also vertically fixed to the bottom end of the vertical ring segment 402a. An annular hole 402b-1 is opened in the middle of the sealing ring segment 402b. The second arc mirror 102b is fixed to the wall of the annular hole 402b-1.

[0059] The segmented structure of the outer anode 402 is adapted to the assembly requirements of the base 300 and the second lens 102. The sealing ring 402b improves the structural rigidity and sealing performance of the outer anode 402. The aperture of the annular hole 402b-1 is adapted to the inner anode 401 and the first arc mirror 102a, ensuring that the second arc mirror 102b and the first arc mirror 102a are symmetrically distributed, thereby ensuring that the width of the emission gap C is uniform and ensuring the consistency of the trajectory and the accuracy of focusing after the electron beam is emitted.

[0060] It should be noted that this device can be equipped with a moving adjustment device consisting of a multi-axis robotic arm and a positioning mechanism, which can drive the entire device to move along a preset trajectory, adapting to the additive manufacturing and repair needs of complex-shaped workpieces and realizing omnidirectional flexible forming; at the same time, it is equipped with a forming accuracy detection sensor, which together with an electron beam energy monitor and a wire melting status camera form a complete monitoring device, which monitors the electron beam energy distribution, wire melting status and forming quality in real time, making it easy for the power supply and control system to automatically or manually adjust relevant parameters, further improving processing accuracy.

[0061] During use, first activate the vacuum environment maintenance device, place the entire device inside the vacuum chamber, use a vacuum pump to extract air from the chamber to achieve the preset vacuum level, and monitor the vacuum status in real time using a vacuum detection instrument.

[0062] Subsequently, the power supply and control system starts each component. The filament body 202 is connected to the current through the terminal 203 and generates electrons through thermoemission. The electrons enter the emission area A. At this time, the inner anode 401 and the outer anode 402 are connected to the high voltage power supply to form an electrostatic acceleration and focusing electric field. The constraint surface B of the first lens 101 provides lateral constraint and trajectory guidance for the electrons in the emission area A, suppressing electron dissipation and guiding the electrons to move towards the emission gap C.

[0063] Furthermore, after the electrons pass through the emission gap C, the first arc mirror 102a and the second arc mirror 102b of the second lens 102 perform secondary focusing of the electron beam, further improving the concentration of the electron beam; at the same time, the wire feeding device is started, and the wire is fed uniformly to the electron beam focusing area along the central axis of the device through the wire feeding hole 303 of the base 300 and the wire feeding channel 401a of the inner anode 401; the focused annular electron beam surrounds and melts the central wire in 360°, and the melted wire is deposited on the surface of the workpiece according to a preset trajectory to realize additive manufacturing or repair.

[0064] During operation, the voltage of the first lens 101 is adjusted by the power supply and control system to achieve independent control of the size and position of the electron beam spot. The filament current is adjusted to achieve precise control of the beam current. The entire device is moved by the moving adjustment device to adapt to the workpiece processing trajectory. The monitoring device monitors the electron beam energy, filament melting state and forming quality in real time. If parameter deviation occurs, the control system adjusts the relevant parameters in time to ensure processing quality.

[0065] Furthermore, the cooling device can be selected to continuously cool each high-temperature component or to cool each high-temperature component at fixed intervals to avoid damage to the components; after processing is completed, the power supply of each component is turned off in sequence, and after the device cools down, the vacuum environment maintenance device is turned off, the processed workpiece is taken out, and the entire additive manufacturing or repair process is completed.

[0066] Finally, it should be noted that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A filament coaxial thermionic cathode electron beam fuse additive manufacturing and repair apparatus, characterized by: include, The lens assembly (100) includes a first lens (101) and a second lens (102) fixed to the middle of the bottom end of the first lens (101). An emission area (A) is formed between the first lens (101) and the second lens (102), and a filament assembly (200) is disposed in the emission area (A). The first lens (101) has a constraint surface (B) on the side in contact with the emission area (A), and the second lens (102) has an emission gap (C). The electron beam formed in the emission area (A) is adjusted by the constraint surface (B) and passes through the emission gap (C) to be focused on the filament.

2. The filament bundle coaxial hot cathode electron beam fused wire additive manufacturing and repair apparatus according to claim 1, characterized in that: The first lens (101) includes a first lens segment (101a) and a second lens segment (101b) fixed at an angle to it, the angle facing the emission area (A), and the constraint surface (B) is a concave surface enclosed by the angle. The first lens segment (101a) and the second lens segment (101b) are both annular structures.

3. The filament bundle coaxial hot cathode electron beam fused wire additive manufacturing and repair apparatus according to claim 2, characterized in that: The second lens (102) includes a first arc mirror (102a) and a second arc mirror (102b) that do not contact each other. The inner arc surfaces of the first arc mirror (102a) and the second arc mirror (102b) face the wire, and the outer arc surfaces are in contact with the emission area (A). The gap between the first arc mirror (102a) and the second arc mirror (102b) is the emission gap (C).

4. The filament bundle coaxial hot cathode electron beam fused wire additive manufacturing and repair apparatus according to claim 3, characterized in that: The filament assembly (200) includes a retainer (201), a filament body (202), and a terminal block (203), wherein the retainer (201) is fixed to the filament body (202).

5. The filament bundle coaxial hot cathode electron beam fused wire additive manufacturing and repair apparatus according to claim 4, characterized in that: The filament body (202) is a single ring structure, and the terminals (203) are vertically fixed at the beginning and end of the filament body (202).

6. The filament bundle coaxial hot cathode electron beam fused wire additive manufacturing and repair apparatus according to claim 4, characterized in that: The filament body (202) includes several groups of arc-shaped rings (202a) arranged in a ring. Each group of arc-shaped rings (202a) is fixed with at least one fixture (201), and each end of the arc-shaped ring (202a) is vertically fixed with a terminal post (203).

7. The filament bundle coaxial hot cathode electron beam fused wire additive manufacturing and repair apparatus according to any one of claims 4 to 6, characterized in that: The radial cross-section of the filament body (202) has a regular geometric shape with symmetrical distribution.

8. The filament bundle coaxial hot cathode electron beam fused wire additive manufacturing and repair apparatus according to claim 7, characterized in that: It also includes a base (300) and an anode assembly (400), the anode assembly (400) including an inner anode (401) and an outer anode (402), the inner anode (401) and the outer anode (402) being fixed to the middle of the bottom end of the base (300), and the inner anode (401) being disposed inside the outer anode (402); The first lens (101) is coaxially disposed between the inner anode (401) and the outer anode (402). The base (300) has a mounting hole (301) and the terminal (203) passes through the mounting hole (301) and extends to the top of the base (300).

9. The filament bundle coaxial hot cathode electron beam fused wire additive manufacturing and repair apparatus according to claim 8, characterized in that: The first lens segment (101a) has a perforation (101a-1), and the fixer (201) passes through the perforation (101a-1) and is fixed to the bottom end of the base (300); The top of the first lens (101) is also fixed with several sets of connecting sleeves (302), which connect and fix the first lens (101) and the base (300).

10. The filament bundle coaxial hot cathode electron beam fused wire additive manufacturing and repair apparatus according to claim 8 or 9, characterized in that: The base (300) has a wire feeding hole (303) in the middle, and the inner anode (401) has a wire feeding channel (401a) in the middle. The inner anode (401) is fixed to the first arc mirror (102a) by an expansion ring (401b). The external anode (402) includes a vertical ring segment (402a) that is vertically fixed to the base (300). A sealing ring segment (402b) is also vertically fixed to the bottom end of the vertical ring segment (402a). An annular hole (402b-1) is opened in the middle of the sealing ring segment (402b). The second arc mirror (102b) is fixed to the wall of the annular hole (402b-1).

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