阅读说明：本技术 一种具有光圈阀的可闭合栅极系统 (Closable grid system with diaphragm valve ) 是由 王伟宗 付宸聪 李亦非 于 2020-11-10 设计创作，主要内容包括：本发明公开了一种具有光圈阀的可闭合栅极系统,包括同轴安装的光圈阀结构和栅极结构,光圈阀结构包括保护盖、调节器和叶片组,栅极结构包括屏栅、栅间绝缘件和加速栅。本发明的栅极系统在不影响比冲性能的前提下具有推力多级调节能力；具有开度调节能力,能实现大幅度节流；可开关特定的栅孔；栅极系统可关闭和密封。(The invention discloses a closable grid system with an aperture valve, which comprises an aperture valve structure and a grid structure, wherein the aperture valve structure and the grid structure are coaxially arranged, the aperture valve structure comprises a protective cover, a regulator and a blade group, and the grid structure comprises a screen grid, an inter-grid insulating part and an accelerating grid. The grid system has the thrust multi-stage regulation capacity on the premise of not influencing the specific impulse performance; the opening degree adjusting capability is realized, and the large-amplitude throttling can be realized; a switchable specific gate hole; the gate system may be closed and sealed.)

1. Closable grid system with iris valve, comprising an iris valve structure and a grid structure mounted coaxially, wherein the iris valve structure comprises a protective cover (1), a regulator (2) and a blade set (3) mounted from top to bottom, and the grid structure comprises a screen (4), an inter-grid insulator (5) and an accelerator grid (6) mounted from top to bottom, wherein,

the protective cover (1) is in a ring shape and is used for protecting and limiting the regulator (2);

the regulator (2) is annular, the surface of the regulator is provided with regulator guide rails (202) in a circumferential array, and the regulator (2) can rotate through an external actuating device;

the blade group (3) comprises a plurality of blades (301) with the same structure, each blade (301) is provided with a blade circular boss (302) and a blade straight boss (303), and the regulator guide rail (202) is tightly contacted with the blade circular boss (302);

the screen grid (4) is circular, screen grid holes (401) are formed in the screen grid (4), and screen grid guide rails (402) are arranged in a circumferential array; the screen grid guide rail (402) is tightly contacted with the straight blade boss (303), the blade group (3) and the screen grid (4) are installed in an attaching mode, the thickness magnitude of the blade group and the screen grid (4) is equal, and the voltage is equal; the blade group (3) has a plurality of stop positions in the moving process, each position of the blade group (3) does not cut the screen grid holes (401), and the contact area of each screen grid hole (401) contacted with the plasma is complete;

the inter-grid insulating part (5) is in a ring shape and is used for insulating and separating the screen grid (4) from the accelerating grid (6), and the inner diameter of the ring of the inter-grid insulating part (5) is equal to the effective working diameter of the screen grid (4);

the accelerating grid (6) is circular, and accelerating grid holes (601) which correspond to the screen grid holes (401) one by one are formed in the surface of the accelerating grid;

the protective cover (1), the screen grid (4), the inter-grid insulating part (5) and the accelerating grid (6) are fixedly connected and cannot move relatively;

the action process of the closable gate system is as follows: after a control command is sent, the rotating motion of the regulator (2) is converted into the blade group (3) is in the translating motion of the surface of the screen grid (4) and realizes the opening regulation of the blade group (3), namely, an external actuating device drives the regulator (2) to move along the plane rotating motion of the central axis of the closable grid system, the blade circular boss (302) moves along the corresponding regulator guide rail (202), the blade straight boss (303) moves along the corresponding screen grid guide rail (402) and shields the grid holes (401), the contact effect of plasma in an ionization chamber is changed, the number of the grid holes (401) is changed, the opening regulation of the grid system is realized, and the function of closing is realized.

2. A closable grid system with aperture valve according to claim 1, characterized in that on the screen (4) screen apertures (401) are provided in a multistage concentric equidistant regular polygon arrangement within an ion beam extraction circle of diameter effective working diameter, wherein the multistage concentric equidistant regular polygon arrangement satisfies the following condition:

setting a standard value d of the space between the screen grid holes (401) and a maximum deviation value e of the space between the screen grid holes (401); making at least two concentric regular polygons with corresponding sides parallel to each other in the ion beam current leading-out circle, wherein the centers of the concentric regular polygons are superposed with the center of the ion beam current leading-out circle; enabling the vertex distance difference between the concentric regular polygons to be equal to d, forming a multi-stage concentric regular polygon with equal intervals, and enabling the multi-stage concentric regular polygon to correspond to the opening degree of the blade group (3); the screen grid holes (401) are arranged among the multiple stages of concentric regular polygons with equal vertex intervals, the screen grid holes (401) are not cut by the concentric regular polygons, and the intervals of the screen grid holes (401) are d +/-e.

3. A closable grid system with iris valve according to claim 1 or 2, characterized in that the external actuating means is connected to the regulator (2) by a gear transmission.

4. A closable grid system with iris valve according to claim 1 or 2, characterized in that the external actuating means is connected to the regulator (2) by engaging regulator gear teeth (201) on the regulator (2).

5. A closable gate system with an aperture valve according to claim 1 or 2, wherein the operation modes of the closable gate system comprise a normal mode, a sealing mode and a throttling mode, wherein,

the common mode is that the opening degree of the blade group (3) is adjusted to be maximum, and all the screen grid holes (401) are opened;

in the sealing mode, namely the opening degree of the blade group (3) is adjusted to be minimum, the screen grid holes (401) are all closed, and the closable grid system can realize sealing;

the throttling mode is that the opening degree of the blade group (3) is between the maximum and the minimum, the screen grid holes (401) on the outer side of a regular polygon formed by the blade group (3) are closed due to being shielded by the blade group (3), the rest screen grid holes (401) work normally, the number of the screen grid holes (401) used for leading out ion beam current in the closable grid system can be adjusted, and throttling is achieved.

6. The closable grid system with an aperture valve as claimed in claim 5, wherein the closable grid system is used for a double-sided ion thruster, and the double-sided grid system is composed of two sets of the closable grid system, the thruster is in a single-sided thrust mode, and one side of the closable grid system enters a sealing mode; the thruster is in a bilateral thrust mode, and the blade group (3) structures of the two sets of closable grid systems are adjusted to enable the opening degrees to be different, so that thrusts with different sizes can be obtained on two sides.

7. Closable grid system with iris valve according to claim 1 or 2, characterized in that the set of blades (3), the screen (4) and the accelerator grid (6) are made of metallic material.

8. Closable grid system with iris valve according to claim 1 or 2, characterized in that the set of blades (3), the screen (4) and the accelerator grid (6) are made of molybdenum.

9. A closable grid system with aperture valve according to any of claims 1 to 8, characterized in that the maximum outer envelope diameter of the closable grid system is 50 to 500mm, the thickness of the protective cover (1), the regulator (2), the blades (301), the screen (4) and the accelerator grid (6) is 0.2 to 2.0mm, and the thickness of the inter-grid insulation (5) is 0.5 to 2 mm.

Technical Field

The invention belongs to the technical field of space electric propulsion and ion extraction in an ion source, and particularly relates to a closable grid system with an aperture valve.

Background

The ion thruster is an electric thruster, is used for space electric propulsion (or aerospace plasma propulsion), has the advantages of high specific impulse, wide thrust variation range, mature technology and the like, and is widely applied to attitude and orbit control of spacecrafts at present. The ion thruster has high similarity with an ion source in structure and principle, is an ion source special for the field of space electric propulsion, and is characterized in that a grid system with a grid mesh structure consisting of a large number of small holes is used for accelerating and discharging ions to obtain thrust.

The main structure of the ion thruster generally consists of an ionization chamber, a grid system and a neutralizer. The ionization chamber is used to generate plasma, the grid system is used to extract and accelerate ions, and the neutralizer is used to emit electrons to neutralize the ions accelerated by the grid system. The ion thrusters are mainly classified into a direct current type, a radio frequency type, and an electron cyclotron resonance type according to a manner of generating plasma in the ionization chamber.

The gate system is composed of at least two gates, i.e., a dual gate system, and there are also gate systems composed of a tri-gate or a quad-gate, but the main principle is the same. Taking the dual-gate system as an example, the dual-gate system is composed of a screen gate, an accelerating gate and an inter-gate insulating part, wherein a certain number of holes are formed in the screen gate and the accelerating gate. The screen is positioned at the upstream and is directly contacted with the plasma in the ionization chamber; the accelerating grid is positioned at the downstream; the grid insulation part is positioned between the screen grid and the accelerating grid, separates the double grids and forms a certain grid distance, and the grid distance is usually about 0.5-2 mm. When the ion thruster works, direct current voltage is applied to the grid system, the direction of an electric field between grids points to the accelerating grid from the screen grid, ions enter the grid system through the screen grid holes, are accelerated by the electric field between the grids, and are finally led out through the accelerating grid holes. A large amount of ions are accelerated and led out to form a high-speed ion beam current, so that the ion thruster generates thrust.

A common ion thruster has only one grid system, referred to herein as a single-sided grid system. For some profiled ion thrusters, they have multiple grid systems. Taking a double-sided ion thruster as an example, it has two gate systems, herein called double-sided gate systems.

In order to realize the precise control of the attitude and orbit by the spacecraft, the ion thruster needs to adjust the thrust to meet the task requirements. For a given working medium, the factors influencing the magnitude of the thrust are mainly the discharge power in the ionization chamber, the flow rate of the working medium and the grid voltage.

At present, the thrust adjusting mechanism of a common ion thruster is provided with 2 types: first, a push-fast adjustment mechanism that changes the gate voltage. Thrust is adjusted by changing grid voltage, and the thrust adjusting speed is high. However, the large change of the grid voltage can cause the sudden change of the potential distribution of a grid sheath layer, the focusing state of the ion beam, the size of the ion beam, the working medium pressure in an ionization chamber and the discharge state, and influence the performance of thrusters such as specific impulse, power and the like. If the working medium flow and the discharge power are not properly adjusted, discharge oscillation and even discharge interruption occur in the ionization chamber. Therefore, at present, the thrust is usually subjected to rapid fine adjustment by using the grid voltage under the condition of fixed working medium flow. The mechanism is faster but the thrust adjustment range is smaller. And secondly, a thrust slow speed adjusting mechanism for changing the flow of the working medium. The thrust is adjusted by changing the flow of the working medium, and the thrust adjusting speed is low. The response speed of the discharge process in the ionization chamber to the working medium flow is low, so that the change of the working medium flow cannot be too violent, and the discharge power must be synchronously adjusted to ensure the energy balance of the discharge process. The mechanism is slower but the thrust force adjustment range is larger.

For a single-sided grid system of a general ion thruster, the disadvantages and problems are as follows: firstly, the existing thrust adjusting mechanism of the ion thruster involves the change of grid voltage, influences the speed and the focusing state of an ion beam, and further influences the specific impulse performance and the beam divergence angle. Second, the ion thruster, when starting up, generally requires a higher working fluid flow to achieve a higher ionization chamber pressure to establish a stable discharge. The conventional grid system has no valve structure, and cannot greatly throttle the ionization chamber to obtain higher working medium pressure at lower working medium flow, so that a large amount of working medium is wasted in the starting process, and the working medium utilization rate and the total impact performance are reduced. Thirdly, the space distribution of the plasma in the ionization chamber of the ion thruster is not uniform, and the density of the plasma generally decreases from the central axis of the ionization chamber to the wall surface of the ionization chamber. The grid holes of the existing grid system are fixed in number and positions, and the nonuniformity of plasma distribution in the ionization chamber causes the decrease trend of the number of ions obtained by the grid holes from a plasma sheath along the central axis of the ionization chamber to the wall surface of the ionization chamber, so that the nonuniformity of ion beam current along with the positions of the grid holes is caused. Particularly, when the thruster works in a low thrust mode, according to a thrust adjusting mechanism, a small working medium flow is usually adopted, the nonuniformity of the ion beam current caused by the nonuniformity of the plasma distribution is more remarkable, and the extra loss of the working medium can be caused by the grid holes far away from the central axis of the ionization chamber.

For a bilateral ion thruster, the task requirement is special, and the thruster is required to generate two ion beam currents with unequal sizes and opposite directions. The design that has been verified at present is to install two grid systems with different structures on both sides of the thruster to meet the task requirements. The thrust adjusting mechanism of the double-sided ion thruster is similar to that of a common ion thruster, but because one ionization chamber is shared, the coupling effect of combined work and a practical control strategy need to be considered.

For the double-sided gate system of the double-sided ion thruster, the disadvantages and problems are as follows: first, the gate systems on both sides have different structures and are complex, which is not conducive to design, manufacturing and manufacture, and cannot ensure that the gate systems on both sides are in the optimum current conducting state at the same time. Secondly, when the bilateral ion thruster is used for attitude and orbit control of a satellite, the thruster is in a unilateral thrust mode, only a unilateral grid system works, and the other lateral grid system cannot be closed and sealed, so that leakage of working media and plasma is caused, generation and maintenance of the plasma in an ionization chamber are affected, and the utilization rate of the working media and the total thrust performance are seriously reduced.

In summary, the normally open gate system of the current ion thruster has many disadvantages and problems, and a closable gate system with a valve structure should be developed, and the current direction is still blank.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a closable grid system with an aperture valve, which is different from the existing grid system, wherein an aperture valve structure is arranged in front of a screen to realize opening adjustment, and closing and sealing can be realized. The specific technical scheme of the invention is as follows:

a closable grid system with an iris valve comprising an iris valve structure and a grid structure mounted coaxially, wherein the iris valve structure comprises a protective cover, a regulator and a blade group mounted from top to bottom, the grid structure comprises a screen, an inter-grid insulator and an accelerator grid mounted from top to bottom, wherein,

the protective cover is in a ring shape and is used for protecting and limiting the regulator;

the regulator is in a ring shape, the surface of the regulator is provided with regulator guide rails in a circumferential array, and the regulator can rotate through an external actuating device;

the blade group comprises a plurality of blades with the same structure, each blade is provided with a blade circular boss and a blade straight boss, and the regulator guide rail is tightly contacted with the blade circular boss;

the screen grid is circular, screen grid holes are formed in the screen grid, and screen grid guide rails are arranged in a circumferential array; the screen grid guide rail is tightly contacted with the straight boss of the blade, the blade group is attached to the screen grid, the thickness magnitude of the blade group is equal to that of the screen grid, and the voltage is equal; the blade group has a plurality of stop positions in the moving process, the blade group does not cut the screen grid holes at each position, and the contact area of each screen grid hole in contact with the plasma is complete;

the inter-grid insulating part is in a ring shape and is used for insulating and separating the screen grid from the accelerating grid, and the inner diameter of the ring of the inter-grid insulating part is equal to the effective working diameter of the screen grid;

the accelerating grid is circular, and accelerating grid holes which are in one-to-one correspondence with the screen grid holes are formed in the surface of the accelerating grid;

the protective cover, the screen grid, the inter-grid insulating part and the accelerating grid are fixedly connected and cannot move relatively;

the action process of the closable gate system is as follows: after a control instruction is sent, the rotary motion of the regulator is converted into the translational motion of the blade group on the surface of the screen grid and the opening adjustment of the blade group is realized, namely, an external actuating device drives the regulator to rotate on a plane along the central axis of the closable grid system, the circular bosses of the blades move along the corresponding guide rails of the regulator, the straight bosses of the blades translate along the corresponding guide rails of the screen grid to shield the grid holes, the effective contact quantity of plasmas in the ionization chamber is changed, the opening adjustment of the grid system is realized, and the function of closing is realized.

Furthermore, on the screen, screen holes are arranged in an ion beam current leading-out circle with the effective working diameter as the diameter according to a multistage concentric equidistant regular polygon arrangement method, wherein the multistage concentric equidistant regular polygon arrangement method meets the following conditions:

setting the standard value d of the screen grid hole spacing and the maximum deviation value e of the screen grid hole spacing; making at least two concentric regular polygons with corresponding sides parallel to each other in the ion beam current leading-out circle, wherein the centers of the concentric regular polygons are superposed with the center of the ion beam current leading-out circle; enabling the vertex distance difference between the concentric regular polygons to be equal to d, forming a multi-stage concentric regular polygon with equal intervals, and enabling the multi-stage concentric regular polygon to correspond to the opening degree of the blade group; the screen grid holes are arranged among the concentric regular polygons with the same vertex spacing in multiple stages, the screen grid holes are not cut by the concentric regular polygons, and the spacing between the screen grid holes is d +/-e.

Further, an external actuating device is connected to the regulator via a gear transmission.

Further, an external actuating device is connected to the actuator via actuator gear teeth on the actuator.

Further, the operation modes of the closable grid system include a normal mode, a sealing mode and a throttling mode, wherein,

the common mode is that the opening degree of the blade group is adjusted to be maximum, and the screen grid holes are all opened;

in the sealing mode, namely the opening degree of the blade group is adjusted to be minimum, all the screen grid holes are closed, and the closable grid system can realize sealing;

the throttling mode is that the opening degree of the blade group is between the maximum and the minimum, the screen grid holes on the outer side of the regular polygon formed by the blade group are closed due to being shielded by the blade group, the rest screen grid holes work normally, the number of the screen grid holes for leading out ion beam current in the closable grid system can be adjusted, and throttling is realized.

Furthermore, the closable grid system is used for a bilateral ion thruster, the bilateral grid system is formed by two sets of the closable grid systems, the thruster is in a single-side thrust mode, and the closable grid system at one side enters a sealing mode; the thruster is in a bilateral thrust mode, the blade group structures of the two sets of closable grid systems are adjusted to enable the opening degrees to be different, and thrusts with different sizes can be obtained on two sides.

Further, the blade group, the screen bars and the accelerating bars are made of metal materials.

Further, the blade assembly, the screen and the acceleration grid are made of molybdenum.

Further, the maximum outer envelope diameter of the closable gate system is 50-500mm, the thickness of the protective cover, the adjuster, the blade, the screen grid and the accelerating grid is 0.2-2.0mm, and the thickness of the inter-grid insulator is 0.5-2 mm.

The invention has the beneficial effects that:

1. the grid system can adjust the number of the screen grid holes contacted with plasma in the ionization chamber, so that the conventional grid system obtains the capabilities of multi-gear throttling and sealing closing;

2. the invention provides a novel thrust adjusting mechanism, which has the capability of adjusting the thrust in multiple stages, does not need to adjust the grid voltage, does not influence the specific impulse performance, and simultaneously improves the working medium utilization rate and the total impulse performance;

3. the invention can reduce the waste of working medium in the starting process of the ion thruster and improve the utilization rate and the total impact performance of the working medium;

4. the grid system can close the grid hole far away from the central axis of the ionization chamber under the low thrust mode of the thruster, so that the working medium utilization rate and the ion beam current uniformity are improved;

5. the bilateral grid systems of the bilateral ion thruster have the same structure, and the bilateral thrust can be different; when the bilateral ion thruster is in a unilateral thrust mode, the closable grid system on one side can be closed and sealed, leakage of working media and plasma is prevented, and the working medium utilization rate and the total impact performance are improved.

Drawings

In order to illustrate embodiments of the present invention or technical solutions in the prior art more clearly, the drawings which are needed in the embodiments will be briefly described below, so that the features and advantages of the present invention can be understood more clearly by referring to the drawings, which are schematic and should not be construed as limiting the present invention in any way, and for a person skilled in the art, other drawings can be obtained on the basis of these drawings without any inventive effort. Wherein:

FIG. 1 is a schematic diagram of the overall structure of the gate system of the present invention;

FIG. 2 is a schematic top view of the overall structure of the present invention;

FIG. 3 is an exploded view of the structure of the present invention;

FIG. 4 is a schematic view of the regulator of the present invention;

FIG. 5 is a schematic view of a blade configuration according to the present invention;

FIG. 6 is a schematic diagram of a screen grid structure according to the present invention.

The reference numbers illustrate:

1-protective cover, 2-adjuster, 201-adjuster gear teeth, 202-adjuster guide rail, 3-blade group, 301-blade, 302-blade round boss, 303-blade straight boss, 4-screen grid, 401-screen grid hole, 402-screen grid guide rail, 5-inter-grid insulator and 6-accelerating grid.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments of the present invention and features of the embodiments may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

The prior art does not contemplate or implement the improvements made by the present invention, mainly because: firstly, in a common ion thruster, a grid system is only used for leading out charged particles or leading in electrons, is in a normally open state, does not have the requirements of closing and sealing, and belongs to a normally open grid system. The grid system in the invention has a valve structure, can be closed, and is different from a normally open grid system. Second, before the advent of the double-sided ion thruster, the conventional ion thruster did not require the gate system to have the functions of closing and sealing, i.e., did not have this requirement. The double-side ion thruster continues to use the original grid system according to the inertia thinking, and the defect of working medium waste in a single-side thrust mode is not found. Third, the gate holes of the conventional gate system are usually arranged at equal intervals to obtain the maximum number of holes. The arrangement of the gate holes is not necessarily changed under the condition that no external structure interferes with the gate holes.

The grid system does not influence the specific impulse performance, and the thrust adjusting mechanism and the matching are adopted, so that the problem that the thrust adjusting mechanism of the conventional ion thruster relates to the change of grid voltage and influences the specific impulse performance can be solved; the grid system has the opening adjusting capacity, can realize large-amplitude throttling, and solves the problems that the grid system of the conventional ion thruster belongs to a normally open type, a grid hole cannot be closed, the grid system cannot realize large-amplitude throttling, a large amount of working media are wasted in the starting process, and the working medium utilization rate and the total impact performance are reduced; the grid system can switch specific grid holes, and can solve the problems that the size of ion beam current led out from the grid holes is not uniform due to the non-uniform distribution of plasma in the ionization chamber, and the grid holes far away from the central axis of the ionization chamber cannot be closed, so that the additional loss of working media is caused; the grid system can be closed and sealed, so that the problems that when the double-side ion thruster is in a single-side thrust mode, the grid system on one side cannot be closed and sealed, working media and plasma are leaked, and the utilization rate of the working media and the total impact performance are seriously reduced are solved; in addition, the grid system has a simple structure and the same bilateral structure, and can realize different bilateral thrust.

As shown in fig. 1 to 3, a closable grid system with an aperture valve comprises an aperture valve structure and a grid structure which are coaxially installed, wherein the aperture valve structure comprises a protective cover 1, a regulator 2 and a blade group 3 which are installed from top to bottom, and the grid structure comprises a screen 4, an inter-grid insulator 5 and an accelerator grid 6 which are installed from top to bottom, wherein,

the protective cover 1 is annular and is used for protecting and limiting the regulator 2 and is also used for being matched and connected with other components of the ion thruster;

the regulator 2 is annular, the surface of the regulator 2 is provided with regulator guide rails 202 in a circumferential array, and the regulator 2 can rotate through an external actuating device;

the blade group 3 comprises a plurality of blades 301 with the same structure, each blade 301 is provided with a blade circular boss 302 and a blade straight boss 303, and the regulator guide rail 202 is tightly contacted with the blade circular boss 302; the blade is a plane blade or a curved blade with the same curvature as the curved screen 4;

the screen 4 is circular, screen holes 401 are arranged on the surface of the screen 4, and screen guide rails 402 are arranged in a circumferential array; the screen grid guide rail 402 is tightly contacted with the straight blade boss 303, the blade group 3 and the screen grid 4 are installed in a fitting manner, the thickness magnitude of the two is equal, and the voltage is equal;

the arrangement of the screen holes 401 on the screen 4 is different from the arrangement of the screen holes with the same pitch in the prior art. As shown in fig. 6, 12 blades form a regular dodecagon aperture of variable size according to the structure of the blade group 3. The screen grid holes 401 are not arranged at equal intervals, but arranged within a certain interval range, so that a plurality of stay positions are arranged in the moving process of the blade group 3, the blade group 3 at each position cannot cut the screen grid holes 401, the contact areas of all the screen grid holes 401 contacted with plasma are ensured to be complete, and therefore the throttling mode of the grid system capable of being closed has a multi-gear working condition, namely, the diaphragm valve has multi-gear opening.

The inter-grid insulator 5 is in a ring shape and is used for insulating and separating the screen grid 4 from the accelerating grid 6, and the inner diameter of the ring of the inter-grid insulator 5 is equal to the effective working diameter of the screen grid 4;

the accelerating grid 6 is circular, and accelerating grid holes 601 which correspond to the screen grid holes 401 one by one are formed in the surface of the accelerating grid;

the protective cover 1, the screen grid 4, the inter-grid insulating part 5 and the accelerating grid 6 are fixedly connected and cannot move relatively;

the action process of the gate system capable of being closed is as follows: after a control instruction is sent, the rotation motion of the regulator 2 is converted into the translation motion of the blade group 3 on the surface of the screen grid 4, and the opening adjustment of the blade group 3 is realized, namely, an external actuating device drives the regulator 2 to rotate on the plane along the central axis of the closable grid system, the circular blade boss 302 moves along the corresponding regulator guide rail 202, the straight blade boss 303 translates along the corresponding screen grid guide rail 402, the screen grid holes 401 are shielded, the number of effective screen grid holes 401 in contact with plasma in an ionization chamber is changed, the opening adjustment of the grid system is realized, and the function of closing is realized.

In some embodiments, the screen apertures 401 are arranged in a multistage concentric equidistant regular polygon arrangement within the ion beam extraction circle with the effective working diameter as the diameter on the screen 4, wherein the multistage concentric equidistant regular polygon arrangement satisfies the following condition:

setting a standard value d of the space between the screen grid holes 401 and a maximum deviation value e of the space between the screen grid holes 401; making at least two concentric regular polygons with corresponding sides parallel to each other in the ion beam current leading circle, wherein the center of each concentric regular polygon is superposed with the center of the ion beam current leading circle; making the vertex distance difference between the concentric regular polygons equal to d to form a multi-stage concentric regular polygon with equal space, which corresponds to the opening degree of the blade group 3; the screen grid holes 401 are arranged among the concentric regular polygons with the same vertex spacing in multiple stages, the screen grid holes 401 are not cut by the concentric regular polygons, and the spacing between the screen grid holes 401 is d +/-e.

In some embodiments, the external actuation means is connected to the regulator 2 by a gear transmission.

In some embodiments, the external activation device is coupled to the regulator 2 via regulator gear teeth 201 on the regulator 2.

In some embodiments, the external actuating device may also be connected to the regulator 2 by a worm gear, an actuating rod, or the like.

In some embodiments, the operation modes of the closable grid system include a normal mode, a sealing mode and a throttling mode, wherein the normal mode is that the opening degree of the blade group 3 is adjusted to be maximum, the screen grid holes 401 are all opened, and the closable grid system is treated according to the existing grid system; in the sealing mode, the opening degree of the blade group 3 is adjusted to be minimum, the screen grid holes 401 are all closed, and the grid system can be closed to realize sealing; in the throttling mode, the opening degree of the blade group 3 is between the maximum and the minimum, peripheral screen holes 401 far away from the central axis of the closable grid system, namely screen holes 401 on the outer side of a regular polygon formed by the blade group 3 are closed, the rest screen holes 401 work normally, and the number of screen holes 401 for leading out ion beams in the closable grid system can be adjusted, so that throttling is realized.

Specifically, when the ion thruster is started, the grid system can be closed to enter a sealing or throttling mode, the diaphragm valve greatly throttles the working medium, and the pressure of the working medium in the ionization chamber is increased to facilitate the establishment of discharge. When the ion thruster is used for thrust adjustment, the grid system can be closed to enter a throttling or common mode, and the opening degree of the aperture valve is adjusted according to the required thrust. The thrust adjusting mechanism can adjust the number of screen grid holes 401 capable of leading out ion beam current, and throttle the working medium while adjusting the flow of the working medium, so that the working medium pressure and the plasma density in the ionization chamber are maintained, and the consumption of the working medium is reduced. The thrust control mechanism for adjusting the number of the effective screen grid holes 401 does not need to adjust grid voltage, does not affect specific impulse performance, and improves total impulse performance.

In some embodiments, the closable grid system is used for a double-side ion thruster, the double-side grid system is formed by two sets of closable grid systems, the thruster is in a single-side thrust mode, and one side of the closable grid system enters a sealing mode; the thruster is in a bilateral thrust mode, the structures of the blade groups 3 of the two sets of closable grid systems are adjusted to enable the opening degrees to be different, and thrusts with different sizes can be obtained on two sides.

In some embodiments, the blade assembly 3, the screen 4 and the accelerator grid 6 are made of a metallic material. Preferably, the blade assembly 3, the screen 4 and the acceleration grid 6 are made of molybdenum. Because the blade group 3 is attached to the screen 4, has the same voltage and the same structural thickness, the influence on the plasma sheath layer at the upstream of the screen 4 is small.

In some embodiments, the maximum outer envelope diameter of the closable gate system is 50-500mm, the thickness of the protective cover 1, the regulator 2, the blade 301, the screen 4 and the acceleration gate 6 is 0.2-2.0mm, and the thickness of the inter-gate insulator 5 is 0.5-2 mm.

The operation steps of the gate system capable of being closed are as follows:

start → satellite-borne computer injection instruction → thruster system determination condition → closable grid system determination work mode and condition → external actuator device to drive regulator 2 and blade set 3 to move → iris valve to adjust to specified opening → closable grid system to load specified voltage → closable grid system start work → end.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the present invention, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "plurality" means two or more unless expressly limited otherwise.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.