JP2016089654A - Thruster and its process of manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thruster capable of producing larger thrust than that of the conventional thruster without using large solid fuel pellets and provide its process of manufacture.SOLUTION: A thruster 1 in accordance with one preferred embodiment of this invention is a thruster 1 for generating thrust in space. The thruster comprises a solid propellant 2 constituted by piling up a plurality of solid fuel pellets 20; an adhesive agent 3 covering a side surface 2a of the solid propellant 2 so as to bond the plurality of solid fuel pellets 20; a container 5 for storing at least one solid propellant 2 covered by the adhesive agent 3; and resin 4 filling a space between the solid propellant 2 and the inner wall of the container 5 while exposing one end surface 2b of the solid propellant 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a thruster and a manufacturing method thereof.

  As an artificial satellite, instead of mounting a plurality of missions on one large satellite, the missions are divided and arranged on a plurality of micro satellites. Propulsion systems are indispensable for missions using multiple satellites and space environment tests using satellites, but development of thrusters for attitude control and orbit control in ultra-small satellites that require severe restrictions on weight, volume, and power Compared with, development of large thrust thrusters that actively move micro-satellite is not very popular. For this reason, the development of a large thrust microthruster suitable for micro satellites has become a major issue.

  The performance required for a microthruster varies greatly depending on the mission content. Electric propulsion devices such as ion thrusters and hall thrusters are suitable when high-accuracy attitude control and high specific thrust of small satellites are required, but chemical propulsion devices are necessary for orbit control in a short time. Often used. The two-component propulsion system and the one-component propulsion system have a large specific thrust. However, since the propellant supply mechanism is complicated, high technical skill is required to reduce the size. The cold gas thruster has a simple system and high reliability. However, when the propellant is discharged, the pressure in the tank decreases, so that the generated thrust becomes small as it is used. On the other hand, a thruster equipped with a solid propellant does not require a supply mechanism such as a valve or an injector, and thus can be easily miniaturized and obtain a high specific thrust. Patent Documents 1 and 2 disclose a thruster equipped with a solid propellant.

JP 2007-162643 A JP 2003-148248 A

  Solid propellants are commercially available as solid fuel pellets, but the size of commercially available solid fuel pellets is limited. The solid fuel pellets need to have a uniform density from the viewpoints of ignition performance and propulsion performance, and it is not easy to produce solid fuel pellets having a uniform and large density. Therefore, it is desirable to easily realize a large thrust thruster using small solid fuel pellets.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a thruster capable of obtaining a thrust larger than that of a conventional thruster without using a large solid fuel pellet, and a method for manufacturing the thruster.

  A thruster according to a predetermined embodiment of the present invention is a thruster for generating thrust in outer space, and covers a solid propellant formed by stacking a plurality of solid fuel pellets, and a side surface of the solid propellant. An adhesive that bonds a plurality of solid fuel pellets, a container that contains at least one solid propellant that is coated with the adhesive, and an end surface of the solid propellant that is exposed, And a resin that fills the space between the inner wall.

  In the thruster, when one end face of the solid propellant is ignited, the combustion of the solid propellant proceeds from the one end face to the other end face, and finally all the solid propellant burns. In the present invention, by stacking a plurality of solid fuel pellets to form a solid propellant, the amount of solid propellant to be burned can be increased without increasing the size of the solid fuel pellet itself, Thrust can be obtained. In addition, since the side surface of the solid propellant is covered with the adhesive, combustion gas leaks to the side surface, combustion is prevented from proceeding from the side surface, and the combustion area is prevented from rapidly expanding. Thereby, the pressure in the container is prevented from rapidly expanding, and the container is prevented from bursting.

  The solid propellant preferably contains boron and potassium nitrate. As a result, a solid propellant having high ignition performance and propulsion performance in a vacuum can be obtained.

  The resin is preferably an epoxy resin. As a result, during combustion of the solid propellant coated with the adhesive, a small amount of the wall surface of the epoxy resin melts (erosion), and the discharge mass increases. For this reason, a big thrust is obtained compared with the case where an epoxy resin is not used.

  The adhesive is preferably an epoxy adhesive. Due to the high thermal insulation and adhesiveness of the epoxy adhesive, the combustion gas is effectively prevented from leaking to the side of the solid propellant.

  The adhesive preferably coats the side of the solid propellant so that it does not intervene between two adjacent solid fuel pellets. This prevents the combustion from being stopped by the adhesive that has entered between two adjacent solid fuel pellets.

  The container contains a bundle of solid propellants coated with an adhesive, and one end face of each solid propellant is exposed in the same direction. As a result, the cross-sectional area of the solid propellant, that is, the combustion area increases, and a large thrust can be obtained.

  In addition, a space device according to a predetermined embodiment of the present invention includes a thruster including a solid propellant configured by stacking a plurality of solid fuel pellets. Thereby, a space device capable of generating a large thrust can be provided.

  Furthermore, a thruster manufacturing method according to a predetermined embodiment of the present invention is a thruster manufacturing method for generating thrust in outer space, wherein a plurality of solid fuel pellets are stacked and pressed. A step of applying an adhesive to the side of a solid propellant composed of a plurality of solid fuel pellets in a state and bonding the plurality of solid fuel pellets; and at least one solid propellant coated with the adhesive And a step of injecting a resin filling the space between the solid propellant and the inner wall of the container while exposing one end surface of the solid propellant.

  In the above thruster manufacturing method, an adhesive enters between two adjacent solid fuel pellets by applying an adhesive to the side of the solid propellant in a state where a plurality of solid fuel pellets are stacked and pressed. It is prevented. For this reason, even if solid fuel pellets are stacked to form a solid propellant, all of the solid propellant can be burned from one end surface side to the other end surface side, and a thruster that produces a large thrust is manufactured. Is done.

  According to the present invention, it is possible to provide a thruster capable of obtaining a thrust larger than that of a conventional thruster without using a large solid fuel pellet and a method for manufacturing the thruster.

It is sectional drawing which shows the structure of the thruster which concerns on 1st Embodiment. It is a figure for demonstrating the manufacturing method of the thruster which concerns on 1st Embodiment. It is sectional drawing which shows the structure of the thruster which concerns on 2nd Embodiment. It is a figure which shows the apparatus for space carrying the thruster which concerns on this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
1A and 1B are cross-sectional views showing the configuration of the thruster according to the first embodiment, wherein FIG. 1A is a vertical cross-sectional view and FIG. 1B is a cross-sectional view. FIG. 1B corresponds to a cross-sectional view taken along the line AA in FIG.

  The thruster 1 is a thruster for generating thrust in outer space. The thruster 1 includes a solid propellant 2 configured by stacking a plurality of solid fuel pellets 20, an adhesive 3 that covers the side surface 2 a of the solid propellant 2, and bonds the plurality of solid fuel pellets 20. A container 5 for containing the solid propellant 2 coated with the agent 3, and a resin 4 that fills a space between the solid propellant and the inner wall of the container 5 while exposing one end surface 2 b of the solid propellant 2. .

  The material of the solid fuel pellet 20 is not limited. For example, an oxidizing agent such as potassium chlorate, potassium perchlorate, potassium nitrate, ammonium nitrate, ammonium perchlorate, and boron, aluminum, magnesium, titanium, zirconium, carbon, A mixture of a combustible agent such as lead thiocyanate is used. However, a mixture of potassium perchlorate and magnesium is not suitable. As the solid fuel pellet 20, for example, an initiator such as tricinate or diazodinitrophenol may be used alone. Alternatively, the solid fuel pellet 20 may be a mixture of the initiator and the oxidizing agent. The solid fuel pellet 20 may further include a binder exemplified by fluorine rubber, fluorine resin, polyurethane rubber, and polybutadiene rubber.

Among the above-mentioned materials, it is preferable to use a mixture of boron and potassium nitrate (B / KNO ₃ ) as the solid fuel pellet 20. This is because B / KNO ₃ has good ignition performance in a vacuum. A mixture ratio of boron and potassium nitrate of 28:70 has high ignition performance and propulsion performance.

  The solid propellant 2 is configured by stacking a plurality of solid fuel pellets. In the example shown in FIG. 1, ten solid fuel pellets 20 are stacked, but the number is not limited. The shape of the solid fuel pellet 20 is not limited, but a cylindrical shape is preferable. It is because it becomes easy to apply | coat the adhesive agent 3 uniformly to the side surface 2a of the solid propellant 2 because a solid fuel pellet is a cylinder. The side surface 2a of the solid propellant 2 corresponds to the side surface of the cylindrical solid propellant 2, and the one end surface 2b of the solid propellant corresponds to the bottom or top surface of the columnar solid propellant.

  The adhesive 3 is applied to the side surface 2 a of the solid propellant 2 and adheres a plurality of solid fuel pellets 20. The adhesive 3 may be an organic adhesive that is excellent in the adhesiveness of the solid fuel pellet 20 and does not easily burn when the solid propellant 2 is burned, and an epoxy adhesive is preferably used. For example, Araldite (registered trademark), which is an epoxy adhesive, can be used. Due to the high thermal insulation and adhesiveness of the epoxy adhesive, the combustion gas is effectively prevented from leaking to the side of the solid propellant. Further, the adhesive 3 is applied to the side surface of the solid propellant 2 so as not to be interposed between two solid fuel pellets 20 adjacent to each other. This prevents the combustion from being stopped by the adhesive 3 that has entered between the solid fuel pellets 20 and the solid fuel pellets 20.

  The resin 4 is not limited as long as it has a high heat insulating property, but an epoxy resin is preferably used. This is because epoxy resins are excellent in terms of light weight, availability, and low cost in addition to high heat insulation. Further, by using the epoxy resin, a small amount of the wall surface of the epoxy resin melts (erosion) during combustion of the solid propellant coated with the adhesive, and the discharge mass increases. For this reason, a big thrust is obtained compared with the case where an epoxy resin is not used. As the epoxy resin, for example, a commercially available crystal resin super clear made by Nissin Resin can be used.

  The container 5 is not particularly limited as long as it is a material having excellent heat resistance used in the aerospace field. For example, stainless steel or titanium alloy is preferably used.

  An ignition device 6 for igniting one end surface 2 b of the solid propellant 2 is disposed on the one end surface 2 b side of the solid propellant 2. Although the structure of the ignition device 6 is not limited, for example, from the viewpoint of simplicity of the structure, it is preferable to use a heating resistance type igniter. The heating resistance igniter includes, for example, two iron electrodes and a nichrome wire attached between the two electrodes. The igniter is used by contacting the nichrome wire at the tip thereof with one end surface 2 b of the solid propellant 2. By applying a voltage between the two electrodes, the nichrome wire generates heat and ignites one end surface of the solid propellant 2 that is in contact with the nichrome wire. As the ignition device 6, an ignition device other than the heating resistance type, for example, a semiconductor laser may be used.

  In the thruster, when the one end surface 2b of the solid propellant 2 is ignited by the ignition device 6, the combustion of the solid propellant 2 proceeds from the one end surface 2b side to the other end surface side of the solid propellant 2, and finally All the solid propellant 2 burns. In this embodiment, by stacking a plurality of solid fuel pellets to form a solid propellant, the amount of solid propellant 2 to be burned can be increased without increasing the size of the solid fuel pellet 20 itself. And the thrust of the thruster can be increased. Moreover, the target thrust can be easily obtained by changing the number of stacked solid fuel pellets 20.

  Moreover, in this embodiment, since the side surface of the solid propellant 2 is covered with the adhesive 3, combustion gas leaks to the side surface of the solid propellant 2 on the way, combustion proceeds from the side surface, and the combustion area rapidly increases. Is prevented from expanding. Thereby, it is possible to prevent the pressure in the container 5 from rapidly expanding due to the rapid expansion of the combustion area, and to prevent the container 5 from bursting.

  Furthermore, in this embodiment, since the adhesive 3 is not interposed between two solid fuel pellets 20 adjacent to each other, the adhesive 3 can prevent the combustion of the solid propellant 2 from being stopped halfway. For this reason, all the solid propellants can be burned effectively, and the target thrust can be obtained.

  Furthermore, in this embodiment, by using an epoxy resin as the resin 4 that covers the periphery of the solid propellant 2 that is coated with the adhesive 3, a small amount of the wall surface of the epoxy resin is generated during the combustion of the solid propellant 2. Melting (erosion) increases discharge mass. For this reason, a thrust can be increased compared with the case where an epoxy resin is not used.

  Next, a method for manufacturing the thruster according to the present embodiment will be described with reference to FIGS.

  As shown in FIG. 2A, a solid fuel pellet 20 is prepared. As the solid fuel pellet 20, a commercially available product can be used. For example, use NAB-1 (mixed explosive of boron and potassium nitrate) manufactured by NOF Corporation. NAB-1 manufactured by NOF Corporation is a pellet having a bottom diameter of φ10 mm and a height of L6.3 mm.

  Next, as shown in FIG. 2 (b), a plurality of solid fuel pellets 20 are stacked, and the solid propellant 2 composed of the plurality of solid fuel pellets 20 is pressed by a pressing means such as a vise. In a state where pressure is applied to both ends of the solid propellant 2, an adhesive 3 is applied to the side surface 2a of the solid propellant 2 to bond a plurality of solid fuel pellets. As the adhesive 3, an epoxy adhesive can be used. Since pressure is applied to both ends of the solid propellant 2, the gap between the solid fuel pellet 20 and the solid fuel pellet 20 can be eliminated, and the adhesive 3 can be prevented from entering the gap. . Although there is no limitation in the film thickness of the adhesive agent 3, it is several mm, for example.

  Next, as shown in FIG. 2 (c), the solid propellant 2 covered with the adhesive 3 is put in the container 5. Then, the resin 4 is injected between the solid propellant 2 and the inner wall of the container 5. For example, Nissin Resin Crystal Resin Super Clear is poured as an epoxy resin. Thereby, the solid propellant 2 is fixed in the container 5 by the resin 4.

  Finally, the ignition device 6 is attached to the one end face 2a side of the solid propellant 2, whereby the thruster 1 is completed.

  In the thruster manufacturing method according to the present embodiment, two solid fuels adjacent to each other are applied by applying the adhesive 3 to the side surface 2a of the solid propellant 2 in a state where a plurality of solid fuel pellets 20 are stacked and pressed. It is possible to prevent the adhesive 3 from entering between the pellets 20. For this reason, even when the solid propellant 2 is configured by stacking the solid fuel pellets 20, all of the solid propellant 2 can be burned from one end surface side to the other end surface side, and a large thrust is obtained. A thruster 1 is manufactured.

  Further, in the thruster manufacturing method according to the present embodiment, the adhesive 3 is uniformly applied to the side surface 2 a of the solid propellant 2 by applying the adhesive 3 to the side surface 2 a of the solid propellant 2 before being put into the container 5. Can be applied.

(Second Embodiment)
3A and 3B are cross-sectional views showing the configuration of the thruster according to the second embodiment, wherein FIG. 3A is a vertical cross-sectional view, and FIG. 3B is a cross-sectional view. FIG. 3B corresponds to a cross-sectional view taken along line BB in FIG.

  In the first embodiment, the thruster includes one solid propellant 2 configured by stacking a plurality of solid fuel pellets 20. However, in the second embodiment, a plurality of solid fuel pellets 20 are stacked. The present invention relates to a cluster type thruster provided with a bundle of solid propellants 2 to be configured.

  A thruster 1a according to the second embodiment includes a bundle of solid propellants 2 coated with an adhesive 3, and one end surface 2b of each solid propellant 2 is exposed in the same direction. Preferably, one end face 2b of all solid propellants 2 forms the same face. As a result, the cross-sectional area of the solid propellant, that is, the combustion area increases, and a large thrust can be obtained. Although not shown, an ignition device is provided on the one end face 2 a side of the solid propellant 2. The ignition device is configured to be able to ignite a plurality of solid propellants 2 simultaneously. Thus, by providing the bundle of solid propellants 2, the thrust of the thruster 1a can be increased to a desired value.

  In particular, in the example shown in FIG. 3, the thruster 1 a contains seven solid propellants 2, one solid propellant 2 is arranged in the center, and the remaining six solid propellants are the central solid propellant 2. It is arranged around. As shown in FIG. 3, the arrangement of seven solid propellants 2 allows the solid propellants 2 to be arranged at a high density on the same principle as the hexagonal close-packing, and thus a small and large thrust thruster 1a. Can be realized. However, the number of the solid propellants 2 is not limited in the cluster type thruster 1a.

  In the cluster-type thruster 1a, the ignition device 6 ignites the end surfaces 2b of the plurality of solid propellants 2 simultaneously. The combustion of each solid propellant 2 proceeds from the one end surface 2b side to the other end surface side of the solid propellant 2, and finally all the solid propellants 2 are combusted. In the present embodiment, the thrust of the thruster can be increased by burning the bundle of solid propellants 2 as compared with the first embodiment. In addition, the same effects as those of the first embodiment can be obtained.

  Next, the manufacturing method of said thruster 1a is demonstrated.

  As shown in FIGS. 2 (a) and 2 (b), the adhesive 3 is applied to the side surface 2a of the solid propellant 2 configured by stacking a plurality of solid fuel pellets 2 in the same manner as in the first embodiment. . A bundle of solid propellants 7 is arranged in a container 5 that can accommodate a plurality of solid propellants 2, and resin is placed in the gap between the solid propellants 2 and in the gap between the solid propellant 2 and the inner wall of the container 5. Pour 4 For example, Nissin Resin Crystal Resin Super Clear is poured as an epoxy resin. Thereby, a plurality of solid propellants 2 are fixed in the container 5. Finally, the ignition device 6 is attached to the one end face 2a side of the solid propellant 2, whereby the cluster type thruster 1a is completed.

  In the thruster manufacturing method according to the present embodiment, it is possible to easily manufacture a thruster with increased thrust as compared to the first embodiment.

(Third embodiment)
3rd Embodiment is related with the apparatus 10 for space provided with the thruster 1a mentioned above. FIG. 4 is a diagram showing a configuration of the space device 10 including the thruster 1a.

  As shown in FIG. 4, the space device 10 includes one or more thrusters 1a. In the example shown in FIG. 4, 109 thrusters are provided. However, the number of thrusters 1a is not limited. Each thruster 1a is the cluster-type thruster described in the second embodiment, and includes a plurality of solid propellants 2. As the thruster 1a, the thruster 1 including only one solid propellant described in the first embodiment may be used.

  The application of the space device 10 shown in FIG. 4 is not limited, and may be, for example, a microsatellite itself or a device that adheres to a microsatellite and corrects the orbit of the microsatellite. Further, it may be a debris removing device that adheres to a used or damaged microsatellite or rocket existing in the space and changes the orbit thereof to discard.

  The space device 10 can generate a large thrust, for example, by jetting all of the plurality of thrusters 1a at the same time. The space device 10 may eject only a part of the plurality of thrusters 1a.

  The present invention is not limited to the above-described embodiment, and those in which those skilled in the art appropriately modify the design are included in the scope of the present invention as long as they have the features of the present invention. . In other words, each element included in the embodiment and its arrangement, material, condition, shape, size, and the like are not limited to those illustrated, and can be appropriately changed. Moreover, each element with which an embodiment is provided can be combined as long as it is technically possible, and the combination thereof is also included in the scope of the present invention as long as it includes the features of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Thruster 2 ... Solid propellant 2a ... Side surface 2b ... One end surface 3 ... Adhesive 4 ... Resin 5 ... Container 6 ... Ignition device 7 ... Pressing means 10 ... Space equipment 20 ... Solid fuel pellet

Claims (8)

A thruster for generating thrust in outer space,
A solid propellant configured by stacking a plurality of solid fuel pellets;
An adhesive that covers a side surface of the solid propellant and adheres the plurality of solid fuel pellets;
A container containing at least one of the solid propellant coated with the adhesive;
A resin that fills a space between the solid propellant and the inner wall of the container while exposing one end surface of the solid propellant;
Thruster with The solid propellant includes boron and potassium nitrate.
The thruster according to claim 1. The resin is an epoxy resin,
The thruster according to claim 1 or 2. The adhesive is an epoxy adhesive,
The thruster according to any one of claims 1 to 3. The adhesive covers the side of the solid propellant so that it does not intervene between the two adjacent solid fuel pellets;
The thruster according to any one of claims 1 to 4. The container contains a bundle of the solid propellant coated with the adhesive, and the one end face of each solid propellant is exposed in the same direction,
The thruster according to any one of claims 1 to 5. The thruster according to any one of claims 1 to 6, comprising:
Space equipment. A method of manufacturing a thruster for generating thrust in outer space,
Stacking and pressing a plurality of solid fuel pellets;
Applying an adhesive to the side of a solid propellant composed of a plurality of the solid fuel pellets in the pressed state, and bonding the plurality of solid fuel pellets;
Containing at least one solid propellant coated with the adhesive in a container;
Injecting a resin that fills a space between the solid propellant and the inner wall of the container while exposing one end surface of the solid propellant;
A method of manufacturing a thruster comprising:

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