A grid structure for electric propulsion device and a manufacturing method thereof, and an electric propulsion device

Abstract

The present invention discloses a grid structure for an electric propulsion device, a manufacturing method thereof, and an electric propulsion device. The grid structure includes a mounting frame and molybdenum wire bars. The mounting frame has a notch in the middle for ion beams to pass through. The molybdenum wire bars are positioned at equal intervals at the notch to form a grid. The present invention uses metal molybdenum wire as the grid of the grid structure of the electric propulsion device, reduces the wide strip structure of the grid, greatly reduces the probability of the grid being sputtered by the ion beam, reduces the grid interception current, and increases the service life of the grid.

Description

Technical Field

[0001] The present invention relates to the field of space electric propulsion technology, and in particular to a grid structure for an electric propulsion device, a manufacturing method thereof, and an electric propulsion device. Background Art

[0002] Electric propulsion device refers to a type of ion electric propulsion device that has a positive and negative electrode structure, such as a field emission electric propulsion device. Field emission micro-electric propulsion devices are ideal power devices for future micro-nano satellite platforms due to their simple structure, high efficiency, and large specific impulse. During use, this type of propulsion device usually relies on a strong electric field between the electrodes to ionize the propellant and eject it under the action of the electric field force, forming a thrust acting on the satellite platform. The trajectory of ion motion after the propellant is ionized is mainly determined by the potential distribution between the electrodes. The grid structures of existing electric propulsion devices are as follows: Figure 1 As shown, the gate structure is an integrated wide-width narrow-slot structure. Since the width of each grid of the gate is relatively wide, the ion beam is accelerated and hits the gate under the action of the electric field force, which leads to thrust loss, gate sputtering damage and large interception current. Summary of the invention

[0003] In view of the problems existing in the prior art, the purpose of the present invention is to provide a gate structure for an electric propulsion device and a manufacturing method thereof, which can greatly reduce the probability of the gate grille being sputtered by the ion beam, reduce the gate interception current, and increase the service life of the gate.

[0004] Another object of the present invention is to provide an electric propulsion device comprising the above-mentioned grid structure.

[0005] To achieve the above objectives, the first aspect of the present invention provides a grid structure for an electric propulsion device, including a mounting frame and molybdenum wire grid bars, wherein the mounting frame has a gap in the middle for the ion beam to pass through, and the molybdenum wire grid bars are positioned at equal intervals at the gap to form a grid grille.

[0006] Furthermore, a plurality of positioning hole groups are provided on both sides of the notch of the mounting frame, the positioning hole groups include a first positioning hole and a second positioning hole provided on both sides of the notch and aligned along a first direction, the plurality of positioning hole groups are arranged at equal intervals along a second direction, and the second direction is perpendicular to the first direction; the molybdenum wire grid spans the notch along the first direction, and both ends of the plurality of molybdenum wire grids are fixed to the mounting frame at equal intervals through the first positioning hole and the second positioning hole.

[0007] Furthermore, two ends of the molybdenum wire grid are respectively passed through the first positioning hole and the second positioning hole for fixing.

[0008] Furthermore, two ends of the molybdenum wire grid are respectively welded to the first positioning hole and the second positioning hole for fixation.

[0009] Furthermore, the material of the mounting frame is molybdenum.

[0010] Furthermore, the diameter of the molybdenum wire grid is 0.1-0.5 mm.

[0011] A second aspect of the present invention provides a method for manufacturing a grid structure for an electric propulsion device, comprising the following steps:

[0012] 1) Processing and installation of the frame;

[0013] 2) polishing the molybdenum wire grid to remove the surface oxide layer of the molybdenum wire grid;

[0014] 3) Fix the molybdenum wire grids at equal intervals on the mounting frame.

[0015] Further, processing and installing the frame includes:

[0016] Process a notch in the middle of the molybdenum plate;

[0017] A plurality of positioning hole groups are processed on both sides of the notch, the positioning hole groups include a first positioning hole and a second positioning hole arranged on both sides of the notch and aligned along a first direction, and the plurality of positioning hole groups are arranged at equal intervals along a second direction, and the second direction is perpendicular to the first direction.

[0018] Further, fixing the molybdenum wire grids at equal intervals on the mounting frame comprises:

[0019] Pass the molybdenum wire grid through the first positioning hole and the second positioning hole of multiple positioning hole groups in sequence, fix one end of the molybdenum wire grid in the first positioning hole of the first group of positioning holes, and fix the other end of the molybdenum wire grid in the second positioning hole of the last group of positioning holes to form a grid.

[0020] A third aspect of the present invention provides an electric propulsion device, comprising a positive electrode and a grid structure, wherein the grid structure is installed on the electric propulsion device through the mounting frame so that the vertical projection of the central axis of the positive electrode coincides with that of an adjacent molybdenum wire grid.

[0021] The present invention adopts metal molybdenum wire as the grid of the grid structure of the electric propulsion device, reduces the wide strip structure of the grid, greatly reduces the probability of the grid being sputtered by the ion beam, reduces the grid interception current, and increases the service life of the grid.

[0022] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 is a schematic diagram of an existing conventional gate structure;

[0025] Figure 2 This is a schematic diagram of the grid structure of an electric propulsion device according to an embodiment of the present invention;

[0026] Figure 3A , Figure 3B This is a schematic diagram of assembling a grid structure on an electric propulsion device according to an embodiment of the present invention;

[0027] Figure 4 The figure is a flow chart of a method for preparing a gate structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the present invention will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0029] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the term "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] The terms "top", "bottom", "above", "lower", and "on", "left-right", and "upper-lower" used throughout the description are relative to the relative positions of components of a device, such as the relative positions of the top and bottom substrates within a device. It is understood that devices are multifunctional regardless of their orientation in space.

[0031] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implying the number of technical features indicated. Thus, the defined "first" and "second" features may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0032] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0033] like Figure 2 As shown, the grid structure for an electric propulsion device of the present invention comprises a mounting frame 1 and molybdenum wire grid bars 2. The mounting frame 1 has a notch 11 in the middle for the ion beam to pass through, and the molybdenum wire grid bars 2 are positioned at equal intervals at the notch 11 to form a grid grid. In this embodiment, the mounting frame 1 is a square, and the notch 11 in the middle of the mounting frame 1 is also a square, but the present invention is not limited thereto, and it can be adaptively changed according to the actual assembly needs on the electric propulsion device.

[0034] The gate structure of the present invention uses metal molybdenum wire as the grid of the gate structure to replace the wide strip structure of the conventional gate, which greatly reduces the probability of the gate grid being sputtered by the ion beam, reduces the gate interception current, and increases the service life of the gate.

[0035] In one embodiment of the present invention, a plurality of positioning hole groups are provided on both sides of the notch 11 of the mounting frame 1, the positioning hole groups include a first positioning hole 12 and a second positioning hole 13 provided on both sides of the notch 11 and aligned along a first direction, the plurality of positioning hole groups are arranged at equal intervals along a second direction, and the second direction is perpendicular to the first direction; the molybdenum wire grid 2 spans the notch 11 along the first direction, and the two ends of the molybdenum wire grid 2 are fixed to the mounting frame 1 at equal intervals through the first positioning hole 12 and the second positioning hole 13 respectively. The positioning hole group provided on the mounting frame 1 can conveniently and accurately locate the installation position of the molybdenum wire grid 2 on the mounting frame, ensuring that the molybdenum wire grid 2 is positioned and fixed at equal intervals on the mounting frame 1. Among them, the molybdenum wire grid 2 can select a long grid bar to pass through the first positioning hole 12 and the second positioning hole 13 of the plurality of positioning hole groups in sequence to form a grid, or can select a plurality of short grid bars to be positioned and fixed at both ends at the corresponding first positioning hole 12 and the second positioning hole 13 to form a grid.

[0036] In one embodiment of the present invention, two ends of the molybdenum wire grid 2 pass through the first positioning hole 12 and the second positioning hole 13 respectively, and are fixed by tying knots at the two ends of the molybdenum wire grid 2 .

[0037] In one embodiment of the present invention, two ends of the molybdenum wire grid 2 are respectively welded to the first positioning hole 12 and the second positioning hole 13 for fixation.

[0038] In one embodiment of the present invention, the diameter of the molybdenum wire grid 2 is 0.1-0.5 mm.

[0039] like Figure 3A and 3BAs shown, the electric propulsion device of the present invention comprises a positive electrode 3 and Figure 2 The grid structure is installed on the electric propulsion device through the mounting frame 1, so that the positive electrode 3 coincides with the vertical projection of the central axis of the adjacent molybdenum wire grid 2. Four mounting holes are set at the four corners of the mounting frame 1, and the grid structure is fixed to the support structure of the electric propulsion device by 4 screws. Since the molybdenum wire grid 2 on the mounting frame 1 is arranged at equal intervals, it can be ensured that the positive electrode 3 coincides with the vertical projection of the central axis of the adjacent molybdenum wire grid 2 after the grid structure is installed on the electric propulsion device, thereby ensuring the directionality of the electric field formed between the grid and the positive electrode, and ensuring that the ion beam can be ejected in the vertical direction.

[0040] like Figure 4 As shown, the method for manufacturing the grid structure for the electric propulsion device of the present invention comprises the following steps:

[0041] Step S410: processing and installing the frame;

[0042] Step S420: polishing the molybdenum wire grid to remove the surface oxide layer of the molybdenum wire grid;

[0043] Step S430: Fix the molybdenum wire grids at equal intervals on the mounting frame.

[0044] Among them, step S410 of processing and installing the frame includes:

[0045] Process a notch in the middle of the molybdenum plate;

[0046] A plurality of positioning hole groups are processed on both sides of the notch, and the positioning hole groups include a first positioning hole and a second positioning hole arranged on both sides of the notch and aligned along a first direction, and the plurality of positioning hole groups are arranged at equal intervals along a second direction, and the second direction is perpendicular to the first direction. Among them, the mounting frame is made of pure molybdenum material, and after being processed according to size, the surface needs to be polished and cleaned to ensure that the surface is smooth and free of foreign matter, and does not affect the electrode discharge.

[0047] Step S430 of fixing a plurality of molybdenum wire grids at equal intervals on the mounting frame comprises:

[0048] Passing the molybdenum wire grid through the first positioning hole and the second positioning hole of the plurality of positioning hole groups in sequence;

[0049] Fix one end of the molybdenum wire grid to the first positioning hole of the first group of positioning holes, and fix the other end of the molybdenum wire grid to the second positioning hole of the last group of positioning holes to form a grid. The metal molybdenum wire needs to be sanded before use to remove the surface oxide layer to prevent the reaction with the oxide during discharge between the electrodes and affect the normal operation of the electric propulsion device. During the installation of the metal molybdenum wire, it is necessary to ensure that the molybdenum wire is in a tensioned state and remains straight, and the two ends of the molybdenum wire are fixed with joints. The metal molybdenum wire can be selected as a long grid bar that passes through the first positioning hole and the second positioning hole of multiple positioning hole groups in sequence to form a grid, or multiple short molybdenum wires can be selected and the two ends are respectively positioned and fixed in the corresponding first positioning hole and the second positioning hole to form a grid.

[0050] The manufacturing method of the grid structure of the present invention simplifies the machining process, omits the chamfering process of the grid edge portion in the conventional machining process, and reduces the electric field concentration problem caused by the "sharp corners" at the grid. The new grid structure is formed by winding metal molybdenum wire to replace the conventional metal molybdenum sheet machining, which minimizes the area of ​​the grid exposed to the ion beam, greatly reduces the probability of the grid being sputtered by the ion beam, reduces the grid interception current, and increases the service life of the grid.

[0051] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0052] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A grid structure for an electric propulsion device, characterized in that: It comprises a mounting frame and molybdenum wire grid bars, wherein the mounting frame has a notch in the middle for the ion beam to pass through, and the molybdenum wire grid bars are positioned at equal intervals at the notch to form a grid grid; a plurality of positioning hole groups are arranged on both sides of the notch of the mounting frame, and the positioning hole groups include a first positioning hole and a second positioning hole arranged on both sides of the notch and aligned along a first direction, and the plurality of positioning hole groups are arranged at equal intervals along a second direction, and the second direction is perpendicular to the first direction; The molybdenum wire grid spans the gap along a first direction, and both ends of the molybdenum wire grid are fixed to the mounting frame at equal intervals through the first positioning hole and the second positioning hole, so that the positive electrode of the electric propulsion device coincides with the vertical projection of the central axis of the adjacent molybdenum wire grid; the diameter of the molybdenum wire grid is 0.1 to 0.5 mm.

2. The gate structure according to claim 1, wherein: The two ends of the molybdenum wire grid are respectively passed through the first positioning hole and the second positioning hole for fixing.

3. The gate structure according to claim 1, wherein: The two ends of the molybdenum wire grid are respectively welded to the first positioning hole and the second positioning hole for fixation.

4. The gate structure according to claim 1, wherein: The material of the mounting frame is molybdenum.

5. A method for manufacturing a grid structure for an electric propulsion device as claimed in claim 1, comprising the following steps: Processing and installation of frames; Polishing the molybdenum wire grid to remove the surface oxide layer of the molybdenum wire grid; The molybdenum wire grids are fixed on the mounting frame at equal intervals.

6. The manufacturing method according to claim 5, characterized in that: The processing and installation frame includes: Process a notch in the middle of the molybdenum plate; A plurality of positioning hole groups are processed on both sides of the notch, the positioning hole groups include a first positioning hole and a second positioning hole arranged on both sides of the notch and aligned along a first direction, and the plurality of positioning hole groups are arranged at equal intervals along a second direction, and the second direction is perpendicular to the first direction.

7. The manufacturing method according to claim 5, characterized in that: Fixing a plurality of molybdenum wire grids at equal intervals on the mounting frame comprises: Passing the molybdenum wire grid through the first positioning hole and the second positioning hole of the plurality of positioning hole groups in sequence; One end of the molybdenum wire grid is fixed to the first positioning hole of the first group of positioning holes, and the other end of the molybdenum wire grid is fixed to the second positioning hole of the last group of positioning holes to form a grid grille.

8. An electric propulsion device, characterized in that: It comprises a positive electrode and a grid structure as described in any one of claims 1 to 4, wherein the grid structure is installed on the electric propulsion device through the mounting frame so that the vertical projection of the central axis of the positive electrode coincides with that of the adjacent molybdenum wire grid.

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