Storage box for porous emission needle of field emission thruster

Abstract

The invention discloses a storage box for a porous emission needle of a field emission thruster. The storage box comprises a storage box bottom barrel, a metal reed and a storage box top cover, a working medium storage cavity is formed in the storage tank bottom barrel, a working medium flow guide groove is formed in the inner wall of the working medium storage cavity, the working medium flow guide groove extends to an opening of the working medium storage cavity and is communicated with a tungsten needle positioning groove, and the tungsten needle positioning groove is used for installing a porous tungsten emitting electrode. The metal reed covers the tungsten needle positioning groove, the metal reed is used for clamping the porous tungsten emitter in the tungsten needle positioning groove, and the metal reed is connected with the storage box bottom barrel to form a structure with adjustable clamping force; the storage box top cover is detachably connected with the storage box bottom barrel, the storage box top cover covers the working medium storage cavity, and the storage box top cover is provided with a through hole for the porous tungsten emitting electrode to penetrate through; the clamping structure is simple, the cost is low, the operation is simple, the porous tungsten emitter is not easy to damage, and the clamping structure can be repeatedly used.

Description

Technical Field

[0001] The invention relates to the technical field of multi-hole emission needles of field emission thrusters, and in particular to a storage tank of multi-hole emission needles of field emission thrusters. Background Art

[0002] The porous needle-type field launch thruster is a new type of electric thruster. It is used as a power system on micro-satellites. With the rapid development of micro-satellites, the research and application of field launch thrusters are becoming more and more extensive. The porous needle-type field launch thruster mainly includes a needle-type porous emitter, an extraction electrode, a tank and a heating element. The needle-type porous emitter is the core component of the thruster, and its operating state determines the performance of the thruster. The tank is the working fluid storage component of the thruster, which is connected to the emitter and ensures the supply of working fluid, and also plays an important role.

[0003] The needle-shaped porous emitter is made of porous metal material. The radius size at the needle tip is extremely small, usually in the micron range. The needle handle diameter is generally 0.5mm and the length is about 10mm. The porous material, large aspect ratio and high-precision needle tip cause the needle-shaped porous emitter to be easily broken and the needle tip to be easily damaged. Secondly, during ground experiments, the working fluid is required to be continuously supplied to the needle tip. The influence of gravity makes it difficult to guide the working fluid to the needle tip. Combining the above two main constraints, the emitter installation steps are required to be few and simple to avoid damaging the emitter, and the working fluid can be guided to flow continuously to the needle tip.

[0004] At present, there are no reports on the design of a tank based on a needle-type porous emitter in China. In the reports on the same type of emitter as the porous needle-type emitter, the solid emitter, the needle-type solid emitter is mainly installed by clamping and fixing it from the bottom or middle of the emitter because the needle-type solid emitter is harder and not easy to break. However, the porous emitter is very brittle and is not suitable for this method. There are also no reports on the working fluid guide structure in the tank.

[0005] In summary, the existing technical solutions based on the needle-type emitter tank design have the following problems:

[0006] (1) The structure is complex and the volume is large, which is not suitable for application in small field launch thrusters;

[0007] (2) The clamping method is not designed for porous emitters with high brittleness, small size and high precision, which can easily cause damage to the porous emitter and the emitter position cannot be adjusted.

[0008] (3) The fin design is used in the fluid guide structure, which has a complex structure, is difficult to process, and is not easy to assemble.

[0009] Therefore, how to solve the above technical problems is particularly important. Summary of the invention

[0010] The object of the present invention is to provide a tank for a multi-hole emission needle of a field emission thruster, so as to solve the problem that the existing clamping method easily causes the emitter to be damaged.

[0011] In order to solve the above technical problems, the present invention provides a tank for a porous emission needle of a field emission thruster, comprising a tank bottom barrel, a metal reed and a tank top cover; a working fluid storage cavity is provided inside the tank bottom barrel, a working fluid guide groove is provided on the inner wall of the working fluid storage cavity, the working fluid guide groove extends to the opening of the working fluid storage cavity and is connected to a tungsten needle positioning groove, and the tungsten needle positioning groove is used to install a porous tungsten emitter; the metal reed covers the tungsten needle positioning groove, the metal reed is used to clamp the porous tungsten emitter in the tungsten needle positioning groove, and the metal reed is connected to the tank bottom barrel to form a structure with adjustable clamping force; the tank top cover is detachably connected to the tank bottom barrel, the tank top cover covers the working fluid storage cavity, and the tank top cover is provided with a through hole for the porous tungsten emitter to pass through.

[0012] In one embodiment, the bottom barrel of the storage tank is made of molybdenum.

[0013] In one of the embodiments, a heating hole is provided at the bottom of the bottom barrel of the storage tank, and the heating hole is used to install a heating rod.

[0014] In one of the embodiments, the tank bottom barrel is provided with screw holes on both opposite sides of the tungsten needle positioning groove; the metal spring is provided with two separately arranged mounting holes; the tank further includes screws, which pass through the mounting holes and are threadedly connected with the screw holes.

[0015] In one embodiment, the screw is made of tungsten.

[0016] In one embodiment, the metal reed is made of tungsten.

[0017] In one of the embodiments, the working medium guide groove is arranged obliquely, and when the storage tank is placed horizontally, the working medium guide groove is used to guide the working medium to the porous tungsten emitter.

[0018] In one embodiment, the tank top cover is made of molybdenum.

[0019] The beneficial effects of the present invention are as follows:

[0020] 1. The metal spring has a certain elasticity. The tungsten needle positioning groove is slightly wider than the diameter of the porous tungsten emitter. The clamped porous tungsten emitter will have a larger force-bearing area, more uniform force, and the force is appropriate, which will not damage the porous tungsten emitter. The clamping structure is made of tungsten, which can work at high temperature and high voltage, and does not react with the working fluid.

[0021] 2. The metal spring pressing and screw fixing method facilitates the adjustment of the height of the porous tungsten emitter and is compatible with porous tungsten emitters of various lengths. At the same time, the size redundancy of the tungsten needle positioning groove can be compatible with some porous tungsten emitters that are not straight enough due to the sintering process, and the needle tip direction angle can be adjusted within a small range.

[0022] 3. The internal working fluid guide groove design can effectively guide the working fluid to flow to the porous tungsten emitter. It has a simple structure and no additional assembly steps.

[0023] 4. The clamping structure is simple, the cost is low, the operation is simple, the porous tungsten emitter is not easily damaged, and it can be reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a structural schematic diagram provided by an embodiment of the present invention;

[0026] Figure 2 yes Figure 1 Schematic diagram of the disassembled structure;

[0027] Figure 3 yes Figure 1 Schematic diagram of the local structure;

[0028] Figure 4 yes Figure 3 Schematic diagram of the structure viewed from above;

[0029] Figure 5 4 is a thruster current curve diagram provided by an embodiment of the present invention.

[0030] The reference numerals are as follows:

[0031] 10. Storage tank bottom barrel; 11. Working fluid storage chamber; 12. Working fluid guide groove; 13. Tungsten needle positioning groove; 14. Heating hole; 15. Screw hole;

[0032] 20. Metal spring; 21. Mounting hole;

[0033] 30. Tank top cover; 31. Perforation;

[0034] 40. Porous tungsten emitter;

[0035] 50. Screws. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0037] The present invention provides a tank for a field emission thruster with a porous emission needle, which can be implemented as follows: Figures 1 to 4 As shown, it includes a tank bottom barrel 10, a metal spring sheet 20 and a tank top cover 30; the tank bottom barrel 10 is provided with a working medium storage chamber 11 inside, and the inner wall of the working medium storage chamber 11 is provided with a working medium guide groove 12, the working medium guide groove 12 extends to the opening of the working medium storage chamber 11 and is connected to a tungsten needle positioning groove 13, and the tungsten needle positioning groove 13 is used to install a porous tungsten emitter 40, for example, this embodiment is used to install a porous tungsten emitter 40 with a radius of 0.5 mm and a length of about 10 mm 0; the width of the metal spring 20 is about 3 mm, the metal spring 20 covers the tungsten needle positioning groove 13, the metal spring 20 is used to clamp the porous tungsten emitter 40 in the tungsten needle positioning groove 13, and the metal spring 20 is connected to the tank bottom barrel 10 to form a structure with adjustable clamping force; the tank top cover 30 is detachably connected to the tank bottom barrel 10, the tank top cover 30 covers the working medium storage cavity 11, and the tank top cover 30 is provided with a through hole 31 for the porous tungsten emitter 40 to pass through.

[0038] Preferably, in this embodiment, the bottom barrel 10 of the storage tank is made of molybdenum to meet the requirements for storing the working fluid.

[0039] like Figure 4 As shown, in this embodiment, a heating hole 14 is provided at the bottom of the storage tank bottom barrel 10, and the heating hole 14 is used to load a heating rod to meet the need for heating during use.

[0040] like Figure 2 As shown, in this embodiment, the bottom barrel 10 of the storage tank is provided with screw holes 15 on both sides opposite to the tungsten needle positioning groove 13; the metal spring 20 is provided with two separately arranged mounting holes 21; the storage tank also includes a screw 50, which is threadedly connected to the screw hole 15 after passing through the mounting hole 21; therefore, by tightening and loosening the screw 50, the clamping force of the metal spring 20 on the porous tungsten emitter 40 can be adjusted.

[0041] Preferably, in this embodiment, the screw 50 is made of tungsten to ensure that it can work at high temperature and high voltage and does not react with the working fluid.

[0042] Preferably, in this embodiment, the metal reed 20 is made of tungsten to ensure that it can work at high temperature and high voltage and does not react with the working fluid.

[0043] like Figure 3 As shown, in this embodiment, the working medium guide groove 12 is arranged obliquely. When the storage tank is placed horizontally, the working medium guide groove 12 is used to guide the working medium to the porous tungsten emitter 40.

[0044] Preferably, in this embodiment, the tank top cover 30 is made of molybdenum to meet the requirements for storing the working medium.

[0045] The implementation steps of the above embodiment are roughly as follows:

[0046] 1. Install the screw 50 and the metal spring 20 on the tank bottom barrel 10. Do not tighten the screw 50. Keep a certain distance between the metal spring 20 and the tungsten needle positioning groove 13 so that the porous tungsten emitter 40 can be placed.

[0047] 2. Place the porous tungsten emitter 40 and determine the height of the porous tungsten emitter 40 .

[0048] 3. Slowly tighten the screw 50 to clamp the metal spring 20 and the tungsten needle positioning groove 13 with the porous tungsten emitter 40.

[0049] 4. After filling an appropriate amount of working medium (such as indium, cesium, etc.) into the working medium storage chamber 11, align the porous tungsten emitter 40 with the through hole 31 of the tank top cover 30, then align the tank top cover 30 with the tank bottom barrel 10, and slowly lower the tank top cover 30 to complete the assembly.

[0050] Compared with the traditional groove direct insertion installation method, this clamping structure is firm and reliable and can achieve stable operation.

[0051] Afterwards, the tank was assembled with other thruster components for launch test verification. By collecting launch test data, the effect of the clamping structure on propellant supply and launch performance was analyzed. Figure 5 Analysis of the current curve shown shows that the propellant flow and supply inside the thruster launch pin are smooth, achieving a smooth launch.

[0052] After adopting the above scheme, at least the following beneficial effects can be achieved:

[0053] 1. The metal spring 20 has a certain elasticity, and the tungsten needle positioning groove 13 is slightly wider than the diameter of the porous tungsten emitter 40. The clamped porous tungsten emitter 40 will have a larger force-bearing area, more uniform force, and the force is appropriate, which will not damage the porous tungsten emitter 40. The clamping structure is made of tungsten, which can work at high temperature and high voltage, and does not react with the working fluid.

[0054] 2. The method of pressing the metal spring 20 and fixing with the screw 50 facilitates the adjustment of the height of the porous tungsten emitter 40 and is compatible with porous tungsten emitters 40 of various lengths. At the same time, the size redundancy of the tungsten needle positioning groove 13 can be compatible with some porous tungsten emitters 40 that are not straight enough due to the sintering process, and the needle tip direction angle can be adjusted within a small range.

[0055] 3. The internal working medium guide groove 12 is designed to effectively guide the working medium to flow toward the porous tungsten emitter 40, with a simple structure and no additional assembly steps.

[0056] 4. The clamping structure is simple, low in cost, easy to operate, and not easy to damage the porous tungsten emitter 40, and can be reused.

[0057] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A tank for a field emission thruster with a porous launch needle, characterized in that: It includes a tank bottom barrel, a metal reed and a tank top cover; A working medium storage cavity is provided inside the bottom barrel of the storage tank, and a working medium guide groove is provided on the inner wall of the working medium storage cavity. The working medium guide groove extends to the opening of the working medium storage cavity and is connected to a tungsten needle positioning groove, and the tungsten needle positioning groove is used to install a porous tungsten emitter; The metal reed covers the tungsten needle positioning groove, the metal reed is used to clamp the porous tungsten emitter in the tungsten needle positioning groove, and the metal reed is connected to the tank bottom barrel to form a structure with adjustable clamping force; The tank top cover is detachably connected to the tank bottom barrel, the tank top cover covers the working medium storage cavity, and the tank top cover is provided with a through hole for the porous tungsten emitter to pass through.

2. The tank according to claim 1, characterized in that The bottom barrel of the storage tank is made of molybdenum.

3. The tank according to claim 1, characterized in that A heating hole is provided at the bottom of the bottom barrel of the storage tank, and the heating hole is used to install a heating rod.

4. The tank according to claim 1, characterized in that The bottom barrel of the storage tank is provided with screw holes on both sides opposite to the tungsten needle positioning groove; The metal spring sheet is provided with two separately arranged mounting holes; The storage box also includes a screw, which passes through the mounting hole and is threadedly connected with the screw hole.

5. The tank according to claim 4, characterized in that The screw is made of tungsten.

6. The tank according to claim 4, characterized in that The metal reed is made of tungsten.

7. The tank according to claim 1, characterized in that The working medium guide groove is arranged obliquely. When the storage tank is placed horizontally, the working medium guide groove is used to guide the working medium to the porous tungsten emitter.

8. The tank according to claim 1, characterized in that The tank top cover is made of molybdenum.

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