Large-aperture double-gate type slidable stress release screen gate structure

Abstract

The invention relates to the technical field of thruster design, in particular to a large-diameter double-grid type slidable stress release screen grid structure which comprises a screen grid mounting ring, an acceleration grid mounting ring, an acceleration grid and a stress release screen grid, the screen grid mounting ring is of an annular structure, and a plurality of first threaded connectors are evenly distributed in the screen grid mounting ring; the acceleration grid electrode installation ring is of an annular structure, and a plurality of second threaded connectors are evenly distributed on the acceleration grid electrode installation ring. The stress release screen grid is of a thin-wall cambered surface structure, a plurality of radial kidney-shaped holes are formed in the fixing area, and fixing screws penetrate through the radial kidney-shaped holes to be correspondingly connected with the first threaded connectors. The acceleration grid is of a thin-wall cambered surface structure, a plurality of first through holes are formed in the fixing area, and fixing screws penetrate through the first through holes to be correspondingly connected with the second threaded connectors. The ion thruster can be used for relieving the stress concentration problem caused by the thin-wall and high-transparency structural characteristics of the screen grid in the process from low-temperature starting to steady-state working of the ion thruster.

Description

Technical Field

[0001] The present application relates to the technical field of thruster design, and in particular to a large-aperture double-grid type slidable stress release screen grid structure. Background Art

[0002] As an advanced space propulsion technology, ion electric propulsion has been widely used in spacecraft attitude and orbit control, deep space exploration propulsion and other tasks due to its advantages such as high specific impulse, long life, and precise adjustment of thrust over a wide range.

[0003] The grid assembly is a key component of the ion thruster. The dual-grid grid is mainly composed of a screen grid and an accelerator grid, both of which are thin-walled curved structures. The required assembled grid spacing is only 0.5-1mm. During the start-up to steady-state operation of the ion thruster, the radiation energy of the discharge chamber bombards the grid assembly, causing stress and non-uniform thermal expansion of the grid. Since the screen grid has lower transparency and thinner wall thickness than the accelerator grid, the structural rigidity and stress concentration problem are obvious. The axial deformation is greater under constraint conditions such as edges, resulting in a sudden decrease in local grid spacing, triggering inter-grid discharge, reduced grid focusing performance, and even causing failure of the grid assembly. This problem becomes more obvious as the gate aperture increases. Summary of the Invention

[0004] The present application provides a large-aperture dual-grid type slidable stress release screen grid structure, which is suitable for metal molybdenum grid type spectroscopy components of different calibers and can be applied to different medium and high power ion thruster interfaces.

[0005] In order to achieve the above-mentioned purpose, the present application provides a large-aperture dual-gate sliding stress-releasing screen grid structure, including a screen grid mounting ring, an acceleration grid mounting ring, an acceleration grid and a stress-releasing screen grid, wherein: the screen grid mounting ring is an annular structure, evenly distributed with multiple first threaded interfaces, and is connected to the ion thruster through the screen grid mounting interface on the external ear; the acceleration grid mounting ring is an annular structure, evenly distributed with multiple second threaded interfaces, and is connected to the ion thruster through the acceleration grid mounting interface on the external ear; the stress-releasing screen grid is a thin-walled arc surface structure, including an opening area and a fixing area, and a plurality of radial waist holes are provided on the fixing area, and the fixing screws pass through the plurality of radial waist holes and are correspondingly connected to the plurality of first threaded interfaces; the acceleration grid is a thin-walled arc surface structure, including an opening area and a fixing area, and a plurality of first through holes are provided on the fixing area, and the fixing screws pass through the plurality of first through holes and are correspondingly connected to the plurality of second threaded interfaces.

[0006] Furthermore, a plurality of countersunk holes are evenly distributed on the screen grid mounting ring.

[0007] Furthermore, the fixed area of ​​the stress release screen grid is provided with first relief holes corresponding to the plurality of countersunk holes.

[0008] Furthermore, a plurality of second through holes are evenly distributed on the accelerating gate mounting ring.

[0009] Furthermore, the fixing area of ​​the acceleration gate is provided with second clearance holes corresponding to the plurality of second through holes.

[0010] Furthermore, the diameter of the second through hole is larger than the diameter of the first through hole.

[0011] Furthermore, the distance between the stress release screen grid and the acceleration grid is 0.5-1 mm.

[0012] Furthermore, the apertures of the stress release screen grid opening area and the acceleration grid opening area are both ≥300 mm, and are both composed of multiple small holes.

[0013] The present application provides a large-aperture dual-gate slidable stress release screen grid structure with the following features:

[0014] Beneficial effects:

[0015] The present application can be used to alleviate the stress concentration problem caused by the thin-walled and high-transparency structural characteristics of the screen grid during the low-temperature start-up to steady-state operation of the ion thruster; through the edge-fixed waist hole design, the screen grid is installed on the screen grid mounting ring with a small tightening torque, which can achieve stress release and radial sliding of the screen grid under thermal load impact, reduce the risk of structural distortion caused by screen grid stress concentration, alleviate the problem of sudden decrease in local grid spacing between the dual grids, improve the grid stability of the ion thruster, and thus optimize the low-temperature start-up performance of the ion thruster. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings that constitute part of this application are used to provide a further understanding of this application and make other features, objects and advantages of this application more apparent. The illustrative embodiment drawings of this application and their descriptions are used to explain this application and do not constitute an improper limitation of this application. In the drawings:

[0017] Figure 1 Schematic diagram of a large-aperture dual-gate slidable stress release screen gate structure provided according to an embodiment of the present application;

[0018] Figure 2 This is a side view of a large-aperture dual-gate slidable stress relief screen gate structure provided according to an embodiment of the present application;

[0019] Figure 3 Schematic diagram of the grid assembly of the stress relief screen provided in accordance with an embodiment of the present application;

[0020] Figure 4 is a cross-sectional view of a grid assembly of a stress relief screen provided in accordance with an embodiment of the present application;

[0021] Figure 5 is a schematic diagram of an accelerating gate assembly according to an embodiment of the present application;

[0022] Figure 6 is a cross-sectional view of an acceleration gate assembly provided according to an embodiment of the present application;

[0023] In the figure: 1-screen grid mounting ring, 11-first threaded interface, 2-acceleration grid mounting ring, 21-second threaded interface, 3-acceleration grid, 31-first through hole, 32-second clearance hole, 4-stress release screen grid, 41-radial waist hole, 42-first clearance hole, 5-screen grid mounting interface, 6-acceleration grid mounting interface. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] In this application, terms such as "upper," "lower," "left," "right," "front," "back," "top," "bottom," "inner," "outer," "center," "vertical," "horizontal," "transverse," and "longitudinal" indicate positions or locations based on the positions or locations shown in the accompanying drawings. These terms are primarily intended to better describe this application and its embodiments and are not intended to limit the devices, elements, or components indicated to having a specific orientation, or to being constructed or operated in a specific orientation.

[0027] Furthermore, some of the above terms may be used to express other meanings besides indicating a position or location. For example, the term "on" may also be used to indicate a dependency or connection in certain circumstances. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0028] Additionally, the term "plurality" shall mean two or more.

[0029] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] like Figure 1-2 As shown, the present application provides a large-aperture dual-gate sliding stress-releasing screen grid structure, including a screen grid mounting ring 1, an acceleration grid mounting ring 2, an acceleration grid 3 and a stress-releasing screen grid 4, wherein: the screen grid mounting ring 1 is an annular structure, evenly distributed with multiple first threaded interfaces 11, and is connected to the ion thruster through the screen grid mounting interface 5 on the external ear; the acceleration grid mounting ring 2 is an annular structure, evenly distributed with multiple second threaded interfaces 21, and is connected to the ion thruster through the acceleration grid mounting interface 6 on the external ear; the stress-releasing screen grid 4 is a thin-walled arc surface structure, including an opening area and a fixing area, and a plurality of radial waist holes 41 are provided on the fixing area, and the fixing screws pass through the plurality of radial waist holes 41 and are correspondingly connected to the plurality of first threaded interfaces 11; the acceleration grid 3 is a thin-walled arc surface structure, including an opening area and a fixing area, and a plurality of first through holes 31 are provided on the fixing area, and the fixing screws pass through the plurality of first through holes 31 and are correspondingly connected to the plurality of second threaded interfaces 21.

[0031] Specifically, the large-aperture dual-gate sliding stress release screen grid 4 structure provided in the embodiment of the present application is mainly for ion thrusters of component-level dual-gate equipment with a grid opening area ≥300mm. By setting multiple waist hole structures in the fixed area of ​​the stress release screen grid 4, radial sliding can be achieved, thereby increasing the grid deformation margin, realizing local thermal stress release, and then increasing the grid axial displacement, improving the steady-state working grid spacing between the screen grid and the acceleration grid, reducing the stress concentration and local deformation risks in the thermal environment working environment of the large-aperture grid, improving the thermally stable grid spacing of the grid, and reducing the frequency of sparking between the dual grids. Among them, the fixing screws pass through the radial waist hole 41 and the first threaded interface 11 in sequence to fix the stress release screen grid 4 on the screen grid mounting ring 1, and at the same time realize the radial sliding of the stress release screen grid 4 relative to the screen grid mounting ring 1; the fixing screws pass through the first through hole 31 and the second threaded interface 21 in sequence to fix the acceleration grid 3 on the acceleration grid mounting ring 2, and the acceleration grid 3 is flipped upside down by the fixing screws, and the fixing screws are assembled by radial uniform torque screws; the screen grid mounting ring 1 and the acceleration grid mounting ring 2 are both designed with external mounting ear structures, and the double grid mounting rings are assembled to the ion thruster discharge chamber interface through the mounting interface on the external ear structure, and the double grid spacing adjustment is realized by circumferentially evenly installing fixing screws.

[0032] Furthermore, a plurality of countersunk holes are evenly distributed on the screen grid mounting ring 1 .

[0033] Furthermore, the fixed area of ​​the stress release screen grid 4 is provided with first relief holes 42 corresponding to the plurality of countersunk holes.

[0034] Furthermore, a plurality of second through holes are evenly distributed on the accelerating gate mounting ring 2 .

[0035] Furthermore, the fixing area of ​​the accelerating gate 3 is provided with second clearance holes 32 corresponding to the plurality of second through holes.

[0036] Specifically, such as Figure 3-6 As shown, the countersunk hole on the screen grid mounting ring 1 is arranged correspondingly to the first clearance hole 42 of the stress release screen grid 4, in order to achieve the assembly and clearance between the stress release screen grid 4 and the screen grid mounting ring 1; the second through hole on the acceleration grid mounting ring 2 is arranged correspondingly to the second clearance hole 32 of the acceleration grid 3, in order to achieve the assembly and clearance between the acceleration grid 3 and the acceleration grid mounting ring 2, the fixing screws of the double grids can be installed in a staggered manner, thereby avoiding contact between the double grids and ensuring the installation distance between the stress release screen grid 4 and the acceleration grid 3.

[0037] Furthermore, the diameter of the second through hole is larger than the diameter of the first through hole 31 , thereby ensuring the stability of installation and fixation.

[0038] Furthermore, the distance between the stress relief screen grid 4 and the acceleration grid 3 is 0.5-1mm. In the embodiment of the present application, the distance between the stress relief screen grid 4 and the acceleration grid 3 is preferably 0.5-1mm, that is, the difference in the length of the mounting screws of the dual-grid external ears does not exceed 2mm. Depending on the actual situation, the distance can be fine-tuned by adding adjustment pads.

[0039] Furthermore, the apertures of the stress relief screen grid 4 and the acceleration grid 3 are both ≥300mm in diameter and are composed of multiple small holes. The overall aperture of the stress relief screen grid 4 and the acceleration grid 3 is ≥300mm, and the interior of each aperture is composed of thousands or tens of thousands of small holes.

[0040] Specifically, in the embodiment of the present application, in order to achieve the sliding of the stress release screen grid 4, the tightening torque of the fixing screws at the waist hole of the stress release screen grid 4 is preferably designed to be 1N.m, and the tightening torque of the fixing screws of the acceleration grid 3 is preferably designed to be 1.4Nm, that is, to ensure that under thermal load, the screen grid with smaller thickness and higher transparency can produce micro-displacement within a certain radial distance of the waist hole, thereby alleviating the phenomenon of stress concentration.

[0041] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A large-aperture dual-gate type slidable stress release screen grid structure, characterized in that: It includes a screen grid mounting ring, an acceleration grid mounting ring, an acceleration grid and a stress relief screen grid, wherein: The screen grid mounting ring is an annular structure, evenly distributed with a plurality of first threaded interfaces, and is connected to the ion thruster through the screen grid mounting interfaces on the external ear; The accelerating grid mounting ring is an annular structure, evenly distributed with a plurality of second threaded interfaces, and is connected to the ion thruster through the accelerating grid mounting interfaces on the external ear; The stress release screen grid is a thin-walled arc surface structure, including an opening area and a fixing area, and a plurality of radial waist holes are provided on the fixing area. The fixing screws pass through the plurality of radial waist holes and are connected to the plurality of first threaded interfaces correspondingly; The accelerating grid is a thin-walled arc surface structure, including an opening area and a fixing area. The fixing area is provided with a plurality of first through holes, and fixing screws pass through the plurality of first through holes and are correspondingly connected to the plurality of second threaded interfaces.

2. The large-aperture dual-gate slidable stress-relieving screen grid structure according to claim 1, characterized in that: The screen grid mounting ring is also evenly distributed with a plurality of countersunk holes.

3. The large-aperture dual-gate slidable stress-relieving screen grid structure according to claim 2, characterized in that: The fixed area of ​​the stress release screen grid is provided with first relief holes corresponding to the plurality of countersunk holes.

4. The large-aperture dual-gate slidable stress-relieving screen grid structure according to claim 3, characterized in that: The accelerating gate mounting ring is also evenly distributed with a plurality of second through holes.

5. The large-aperture dual-gate slidable stress-relieving screen grid structure according to claim 4, characterized in that: The fixing area of ​​the acceleration gate is provided with second clearance holes corresponding to the plurality of second through holes.

6. The large-aperture dual-gate slidable stress-relieving screen grid structure according to claim 5, characterized in that: The aperture of the second through hole is larger than that of the first through hole.

7. The large-aperture dual-gate slidable stress-relieving screen grid structure according to claim 6, characterized in that: The distance between the stress release screen grid and the acceleration grid is 0.5-1 mm.

8. The large-aperture dual-gate slidable stress-relieving screen grid structure according to claim 7, characterized in that: The apertures of the stress release screen grid opening area and the acceleration grid opening area are both ≥300 mm, and are both composed of a plurality of small holes.

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