Propellant manufacturing method and propellant manufacturing device

Abstract

To provide a method and an apparatus for manufacturing a propellant to produce a rocket motor with higher performance.SOLUTION: The present invention discloses a method for manufacturing a propellant 51, 52, 53, the propellant 51, 52, 53 including a propellant grain having a first surface on which combustion starts upon ignition and a second surface covered with a wall surface that prevents combustion. The manufacturing method includes: placing a portion of a first propellant having a first burning rate in a first space containing a first position on the second surface; and placing a portion of a second propellant having a second burning rate higher than the first burning rate in a second space containing a second position on the first propellant. The method further includes: placing a portion of a third propellant having a third burning rate higher than the second burning rate in a third space containing a third position on the first surface. The method further includes producing the propellant grain by simultaneously hardening the entireties of the first propellant, the second propellant, and the third propellant.SELECTED DRAWING: Figure 8C

Description

[Technical field]

[0001] The present invention relates to a method and an apparatus for producing propellant, and can be suitably used, for example, in a method and an apparatus for producing propellant used in rocket motors and gas generators of flying objects. [Background technology]

[0002] Rocket motors and gas generators using solid propellants are sometimes used in launch vehicles. Generally, solid propellants are manufactured using a single propellant. In addition, solid propellants are formed by mixing the materials and then casting them into a mold.

[0003] In rocket motors and gas generators, combustion gas is generated when propellant is burned inside a pressure vessel, and thrust can be obtained by ejecting this combustion gas from a nozzle. The combustion pressure caused by the combustion gas varies depending on the area of ​​the burning surface on which the propellant is burning. For example, if the propellant has a simple cylindrical shape and the inner wall surface is burned, the area of ​​the burning surface increases as combustion progresses, and the combustion pressure increases. The pressure vessel must be constructed to withstand the maximum combustion pressure. Therefore, the greater the maximum combustion pressure, the greater the mass of the pressure vessel. One way to improve the performance of rocket motors and gas generators is to reduce the mass of the pressure vessel.

[0004] The mass of the pressure vessel can be reduced by suppressing the maximum value of the combustion pressure. To achieve this, the propellant may be shaped with gaps such as slots or streaks. In this case, the surface of the slots or streaks becomes the combustion surface, so the combustion pressure at the start of combustion is higher than in the case of a simple cylindrical shape. As the combustion progresses, the area of ​​the combustion surface changes depending on the shape of the slots or streaks, so the difference in the combustion area between the start and end of combustion can be reduced compared to the case of a simple cylindrical shape. As a result, the amount of change in the combustion pressure over time can be reduced compared to the case of a simple cylindrical shape. On the other hand, the amount of propellant that can be loaded into the rocket motor is reduced by the amount of the slots or streaks. To improve the performance of the rocket motor, it is possible to load more propellant.

[0005] In relation to the above, Patent Document 1 (Japanese Patent No. 6587231) discloses a multi-pulse rocket motor. This multi-pulse rocket motor includes a pressure vessel, three or more hollow cylindrical propellants, a nozzle, an igniter, and a partition member. Here, the propellants are arranged inside the pressure vessel along the longitudinal direction of the pressure vessel. The nozzle is provided at the rear end of the pressure vessel. The igniter ignites each of the propellants in the pressure vessel, the number of which corresponds to the generation of the required thrust, in order to generate a required thrust at a required multiple timing. The partition member isolates each of the propellants other than the first propellant in the pressure vessel. The multi-pulse rocket motor is characterized in that the partition member has a weak portion in a part of the partition member that is weaker than the other part of the partition member, and the weak portion is arranged over the entire partition member.

[0006] Also, Patent Document 2 (JP Patent No. 6524083) discloses a method for producing a multi-layer propellant grain. The method includes the steps of providing a first propellant formulation and providing a mold configured to provide a structure having an outer shell and a hollow interior when a substance is extruded through the inside. The method further includes the steps of extruding the first propellant formulation through the mold to produce a first propellant layer having an outer shell defining a hollow interior in the shape of a passage having a plurality of open ends, and providing a second propellant formulation that is a low-viscosity gel, liquid, or paste having a viscosity at extrusion of 0 to 2000 Pascal seconds, the viscosity at extrusion being lower than the viscosity at extrusion of the first propellant formulation. The method further includes injecting a second propellant formulation into the passage defined by the first propellant layer to form a second propellant layer disposed within the passage, the second propellant formulation being a low viscosity gel, liquid or paste immediately after injection into the passage, the injection of the second propellant formulation occurring substantially simultaneously with the extrusion of the first propellant formulation, and hardening the second propellant layer after the injecting step such that the second propellant layer attains a viscosity greater than low viscosity sufficient to prevent flow of the second propellant layer within the passage, wherein the first and second propellant layers have different burn rates.

[0007] Patent Document 2 discloses a method for multi-layering a propellant. In the method of Patent Document 2, multiple propellants are individually hardened and then cast again. Therefore, the shape of the multiple propellants is layered in stages. In addition, in the method of Patent Document 2, a series of steps consisting of mixing of materials, casting, and hardening must be repeated every time the number of layers is increased, which increases manufacturing costs. In addition, the first layer is hardened multiple times, and the more the hardening, the more the propellant deteriorates. Furthermore, from the viewpoint of leveling the combustion pressure, it is considered difficult to make the thickness of each layer sufficiently thin. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 6587231 [Patent Document 2] Patent No. 6524083 Summary of the Invention [Problem to be solved by the invention]

[0009] In view of the above, a propellant manufacturing method and a propellant manufacturing apparatus for manufacturing higher performance rocket motors and gas generators are provided. Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0010] The means for solving the problems will be explained below using the numbers used in the (Mode for carrying out the invention). These numbers are added to clarify the correspondence between the description in the (Claims) and the (Mode for carrying out the invention). However, these numbers should not be used to interpret the technical scope of the invention described in the (Claims).

[0011] According to one embodiment, a method for producing a propellant (51, 52, 53, 54, 55) is for producing a rocket motor (2) having a propellant grain (51, 52, 53, 54, 55) having a first surface that initiates combustion upon ignition and a second surface that is joined to a wall surface (6, 21) that prevents combustion. The method includes: Wall (S02) disposing a portion of a second propellant (52) having a second burning rate faster than the first burning rate in a second space including a second position contacting the first propellant (51). The manufacturing method further includes disposing a portion of a third propellant (53) having a third burning rate faster than the second burning rate in a second space including a second position contacting the first propellant (51). Second PropellantThe manufacturing method further includes completely curing the first propellant (51), the second propellant (52), and the third propellant (53) all at once to generate propellant grains (51, 52, 53, 54, 55) (S04). )of , burning rate but Different the law of nature , The materials were mixed It is in a slurry form. Multiple Propellant At a given ratio It further includes mixing to produce.

[0012] According to one embodiment, the propellant manufacturing apparatus (7) is an apparatus for manufacturing propellant grains (51, 52, 53, 54, 55) having a first surface that starts to burn when ignited and a second surface joined to a wall surface (6, 21) that prevents the combustion. The propellant manufacturing apparatus (7) according to the first aspect includes a support device (77), a head (71), a head moving device (76), a control device (78), a plurality of containers (75A, 75B), a mixer (74), and a hardening device (79). The support device (77) supports the wall surface (6, 21). The head (71) places the first propellant (51) in a space including a position in contact with the wall surface (6, 21). The head (71) further disposes a second propellant (52) having a combustion rate different from that of the first propellant (51) and a third propellant (53) having a combustion rate different from that of the first propellant (51) and the second propellant (52) in a predetermined space including a predetermined position under the control of the control device (78). The head moving device (76) moves the head (71) to adjust the position of the head (71) relative to the wall surfaces (6, 21). The control device (78) controls the support device (77), the head (71) and the head moving device (76). The multiple containers (75A, 75B) are configured to dispose the second propellant (52) having a combustion rate different from that of the first propellant (51) and the second propellant (52) in a predetermined space including a predetermined position. the law of nature , The materials were mixed A mixer (74) supplies each of a plurality of propellants in a slurry form, and under the control of a control device (78), mixes the plurality of propellants in a predetermined ratio to generate a propellant having a desired burning rate. The head (71), under the control of the control device (78), places a first propellant (51) contained in the unhardened propellant and having a first burning rate in a first space including a first position in contact with the wall surfaces (6, 21), places a second propellant (52) contained in the unhardened propellant and having a second burning rate faster than the first burning rate in a second space including a second position in contact with the first propellant (51), and places a third propellant (53) contained in the unhardened propellant and having a third burning rate faster than the second burning rate in a third space including a third position in contact with the second propellant (52), and mixes the multiple propellants in a predetermined ratio in a mixer (74) under the control of the control device (78) to produce the first propellant (51), the second propellant (52), and the third propellant (53).The hardening device (79) completely hardens the first propellant (51), the second propellant (52), and the third propellant (53) in their entirety at once to generate propellant grains (51, 52, 53, 54, 55). Effect of the Invention

[0013] According to the embodiment, it is possible to manufacture propellants for manufacturing higher performance rocket motors and gas generators. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view showing an example of the configuration of a flying object according to an embodiment. [Figure 2A] FIG. 2A is a cross-sectional view showing an example of the configuration of a rocket motor according to the related art. [Figure 2B] FIG. 2B is a graph showing an example of a change in combustion pressure over time during operation of the rocket motor of FIG. 2A. [Figure 3A] FIG. 3A is a cross-sectional view showing an example of the configuration of a rocket motor according to another related art. [Figure 3B] FIG. 3B is a graph showing an example of a change in combustion pressure over time during operation of the rocket motor of FIG. 3A. [Figure 4A] FIG. 4A is a cross-sectional view showing an example of a configuration of a rocket motor according to an embodiment. [Figure 4B] FIG. 4B is a graph showing an example of a change in combustion pressure over time during operation of the rocket motor of FIG. 4A. [Diagram 5] FIG. 5 is a diagram showing an example of a configuration of a propellant production apparatus according to an embodiment. [Figure 6] FIG. 6 is a flow chart showing an example of a method for producing a propellant according to an embodiment. [Figure 7A] FIG. 7A is a cross-sectional view showing an example of a state of a propellant in a step of a method for producing a propellant according to an embodiment. [Figure 7B] FIG. 7B is a cross-sectional view showing an example of a state of the propellant in a step of the method for producing the propellant according to one embodiment. [Figure 7C] FIG. 7C is a cross-sectional view showing an example of a state of the propellant in a step of the method for producing the propellant according to one embodiment. [Figure 8A] FIG. 8A is a cross-sectional view showing an example of a state of a propellant in a step of a method for producing a propellant according to an embodiment. [Figure 8B] FIG. 8B is a cross-sectional view showing an example of a state of the propellant in a step of the method for producing the propellant according to one embodiment. [Figure 8C] FIG. 8C is a cross-sectional view showing an example of a state of the propellant in a step of the method for producing the propellant according to one embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing an example of a configuration of a rocket motor according to an embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing an example of a configuration of a rocket motor according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] With reference to the accompanying drawings, embodiments for carrying out a method for producing a propellant and a propellant production apparatus according to the present invention will be described below. In each embodiment, a propellant used in a rocket motor will be described, but the same propellant can also be used in a gas generator.

[0016] (First embodiment) With reference to FIG. 1, it will be described how a rocket motor including a propellant manufactured by the propellant manufacturing method and propellant manufacturing apparatus according to the present embodiment can be used for, for example, a flying object. FIG. 1 is a cross-sectional view showing an example of a configuration of a flying object 1 according to an embodiment. The flying object 1 of FIG. 1 includes a rocket motor 2, a control device 3, and a payload 4. The rocket motor 2 includes an ignition device 22 that ignites the propellant therein. The ignition device 22 may be controlled by the control device 3. The flying object 1 of FIG. 1 can carry the payload 4 to a destination by the thrust of the rocket motor 2. The shape of the flying object 1 may have rotational symmetry around the vehicle axis 10.

[0017] For a better understanding of the propellant manufacturing method and the propellant manufacturing apparatus according to the present embodiment, a rocket motor according to the related art will first be described with reference to FIGS. 2A and 2B.

[0018] FIG. 2A is a cross-sectional view showing an example of a configuration of a rocket motor 200A according to a related art. The rocket motor 200A of FIG. 2A includes a pressure vessel 21, a nozzle 23, and a propellant 5. The pressure vessel 21 of FIG. 2A has a cylindrical shape, one end of which is opened by the nozzle 23, and an ignition device 22 (not shown) is disposed at the other end. The propellant 5 has a cylindrical shape, and has an outer surface, an inner surface, an end surface on the nozzle 23 side, and an end surface on the ignition device 22 side. The propellant 5 is disposed inside the pressure vessel 21, and the outer surface of the propellant 5 is in contact with the inner wall of the pressure vessel 21. When the ignition device 22 ignites the propellant 5, the exposed inner surface and both end surfaces of the propellant 5 start to burn.

[0019] 2B is a graph G1 showing an example of a change in combustion pressure over time during operation of the rocket motor 200A of FIG. 2A. In the graph G1 of FIG. 2B, the horizontal axis represents time, and the vertical axis represents the combustion pressure inside the pressure vessel 21. As the combustion of the propellant 5 progresses, the shape of the propellant 5 changes, and in particular the area of ​​its inner surface increases. As the burning area of ​​the propellant 5 increases, the combustion pressure rises. The upward fluctuation of the combustion pressure continues until the combustion of the propellant 5 is completed.

[0020] The pressure vessel 21 needs to have a structure that can withstand the maximum value of the combustion pressure. Therefore, the greater the maximum value of the combustion pressure, the greater the mass of the pressure vessel 21. In order to improve the performance of the rocket motor 200A, it is possible to reduce the mass of the pressure vessel 21.

[0021] From this viewpoint, by suppressing the maximum value of the combustion pressure, the mass of the pressure vessel 21 can be suppressed. As a method for achieving this, a gap such as a slot or a light beam may be provided in the shape of the propellant 5. Here, a slot is a gap provided so as to include a plane perpendicular to the vehicle axis 10. Also, a light beam is a gap provided so as to include a plane including the vehicle axis 10. A rocket motor provided with a slot will be described with reference to Figs. 3A and 3B.

[0022] Fig. 3A is a cross-sectional view showing one example of a configuration of a rocket motor 200B according to another related art. The rocket motor 200B in Fig. 3A is obtained by providing a slot 50 to the rocket motor 200A in Fig. 2A. In the rocket motor 200B in Fig. 3A provided with the slot 50, the surface area of ​​the propellant 5 is increased compared to the rocket motor 200A in Fig. 2A.

[0023] FIG. 3B is a graph G2 showing an example of a change in combustion pressure over time during the operation of the rocket motor 200B of FIG. 3A. In the graph G2 of FIG. 3B, the horizontal axis represents time, and the vertical axis represents the combustion pressure inside the pressure vessel 21. In the example of FIG. 3A, the increment in surface area is equal to the increment in the combustion area at the start of combustion. Therefore, in the rocket motor 200B of FIG. 3A, the combustion pressure at the start of combustion increases compared to the rocket motor 200A of FIG. 2A. As the combustion progresses, the area of ​​the combustion surface changes depending on the shape of the slot 50, so the difference in the combustion area at the start and end of combustion can be made smaller compared to the simple cylindrical shape of FIG. 2A. As a result, the amount of change in combustion pressure over time can be reduced compared to the rocket motor 200A of FIG. 2A.

[0024] In addition, in the case where a beam of light is provided, the effect obtained is similar to that in the case where the slot 50 is provided, so further detailed explanation will be omitted.

[0025] 3A, the amount of propellant 5 that can be loaded into the rocket motor 200B is reduced by the amount of the slot 50. In order to improve the performance of the rocket motor 200B, it is conceivable to load a larger amount of propellant 5 onto the rocket motor 200B.

[0026] In view of the above, the inventor proposes a method for producing propellant that can level the combustion pressure without providing any voids in the propellant 5, and a propellant production apparatus that uses this method, as described below. Such a rocket motor will be described with reference to Figures 4A and 4B.

[0027] Fig. 4A is a cross-sectional view showing an example of a configuration of a rocket motor 2 according to an embodiment. The rocket motor 2 in Fig. 4A can be obtained by, for example, replacing the propellant 5 of the rocket motor 200A in Fig. 2A with three types of propellants 51, 52, and 53, and adding a restrictor 6. The restrictor 6 is used to prevent combustion of the surfaces of the propellants 51, 52, and 53 that come into contact with the restrictor 6.

[0028] The assembly of propellants 51, 52, and 53 has a cylindrical shape similar to the propellant 5 in Fig. 2A. In other words, this assembly has an outer surface, an inner surface, an end surface on the nozzle 23 side, and an end surface on the ignition device 22 side. This assembly is disposed inside the pressure vessel 21, and the outer surface of the assembly is joined to the inner wall of the pressure vessel 21.

[0029] The restrictor 6 is joined so as to cover the end face of this assembly on the side of the ignition device 22. Therefore, when the assembly of the propellants 51, 52, 53 is ignited by the ignition device 22, among the surfaces of the assembly, the inner surface and the end face on the nozzle 23 side start to burn, but the end face on the ignition device 22 side does not burn from the time of ignition to the end because it is covered by the restrictor 6.

[0030] The inner wall of the pressure vessel 21 also prevents combustion of the portions of the propellants 51, 52, 53 that are in contact with the inner wall. Therefore, the outer surfaces of the assembly are also in contact with the inner wall of the pressure vessel 21 and do not burn.

[0031] The first propellant 51 is bonded to the inner wall of the pressure vessel 21. The third propellant 53 is disposed along the inner surface of the assembly and the end face on the nozzle 23 side. The second propellant 52 is disposed between the first propellant 51 and the third propellant 53. A portion of the second propellant 52 and a portion of the third propellant 53 may be bonded to the inner wall of the pressure vessel 21.

[0032] The three types of propellants 51, 52, and 53 have different burning rates. As an example, among the three types of propellants 51, 52, and 53, the first propellant 51 has the slowest burning rate, the third propellant 53 has the fastest burning rate, and the second propellant 52 has a burning rate faster than the first propellant 51 and slower than the third propellant 53.

[0033] Fig. 4B is a graph G3 showing an example of a change in combustion pressure over time during operation of the rocket motor 2 in Fig. 4A. In the graph G3 in Fig. 4B, the horizontal axis represents time, and the vertical axis represents the combustion pressure inside the pressure vessel 21. When the ignition device 22 is ignited, the third propellant 53 starts to burn first. At this time, the second propellant 52 and the first propellant 51 are covered by the third propellant 53, the inner wall of the pressure vessel 21, and the restrictor 6, and therefore do not burn at the time of ignition.

[0034] When the third propellant 53 is burned up as the combustion of the third propellant 53 progresses, the second propellant 52 is exposed and starts to burn. At this time, the shape of the assembly of the second propellant 52 and the first propellant 51 that still remains is cylindrical, but the area of ​​the inner surface is larger than the area of ​​the inner surface of the assembly of the propellants 51, 52, and 53 before the combustion starts. However, since the burning speed of the second propellant 52 is slower than the burning speed of the third propellant 53, the combustion pressure inside the pressure vessel 21 is kept approximately the same as when the combustion of the third propellant 53 started.

[0035] When the second propellant 52 is burned away as the combustion of the second propellant 52 progresses, the first propellant 51 is exposed and starts to burn. At this time, the shape of the remaining first propellant 51 is cylindrical, but the area of ​​its inner surface is larger than the area of ​​the inner surfaces of the aggregate of the second propellant 52 and the first propellant 51 before the combustion starts. However, since the combustion speed of the first propellant 51 is slower than the combustion speed of the second propellant 52, the combustion pressure inside the pressure vessel 21 is kept approximately the same as when the combustion of the second propellant 52 started.

[0036] In this way, in the rocket motor 2 of this embodiment, while the area of ​​the inner wall surface of the assembly of propellants 51, 52, 53 increases as combustion progresses, i.e., the burning area increases, by appropriately setting the burning rates of the first propellant 51, the second propellant 52, and the third propellant 53 that are burning at that time, it is possible to keep the combustion pressure inside the pressure vessel 21 almost constant.

[0037] As a result, the rocket motor 2 according to this embodiment can reduce the mass of the pressure vessel 21. Also, since there is no need to provide gaps such as slots 50 or beams, the rocket motor 2 according to this embodiment can carry a larger amount of propellants 51, 52, 53. In other words, this embodiment can provide a rocket motor 2 with higher performance.

[0038] An apparatus for manufacturing propellants 51, 52, and 53 according to this embodiment will be described with reference to Fig. 5. Fig. 5 is a diagram showing an example of the configuration of a propellant manufacturing apparatus 7 according to an embodiment. The propellant manufacturing apparatus 7 in Fig. 5 includes a head 71, a flow path 72, a container 73, a head moving device 76, a pressure vessel rotating device 77, a control device 78, and a hardening device 79. The control device 78 may be, for example, a computer including an arithmetic unit, a storage device, an input / output interface, and the like.

[0039] The propellant manufacturing apparatus 7 may function as a so-called layered 3D (three dimensional) printer. That is, under the control of the control device 78, the propellant manufacturing apparatus 7 supplies the propellant stored in the container 73 to the head 71 via the flow path 72, outputs the propellant from the outlet of the head 71, and layers the propellant inside the pressure vessel 21. Here, the propellant in the container 73 is a propellant before hardening and has appropriate fluidity. The container 73 and the flow path 72 may be collectively called a propellant supplying device that supplies the propellant before hardening to the head 71.

[0040] Further, the pressure vessel rotation device 77 rotates the pressure vessel 21 under the control of the control device 78. The pressure vessel rotation device 77 also functions as a support device that supports the pressure vessel 21. The rotation axis that rotates the pressure vessel 21 may be the axis 10 of the flying object 1. The pressure vessel rotation device 77 can control the positional relationship between the pressure vessel 21 and the head 71 in the circumferential direction of the pressure vessel 21 by rotating the pressure vessel 21. In the example of FIG. 5, the axis 10 as the rotation axis is drawn in the horizontal direction, but this embodiment is not limited to this example. As another example, the pressure vessel 21 may be supported so that the axis 10 as the rotation axis faces the vertical direction.

[0041] The head moving device 76 may move the head 71 to an appropriate position under the control of the control device 78. In the example of Fig. 5, the head 71 may move in a direction parallel to the machine axis 10 (X-axis direction) within a plane passing through the machine axis 10, or may move in a direction perpendicular to the machine axis 10 (Y-axis direction), i.e., in the radial direction of the pressure vessel 21. By moving the head 71, the head moving device 76 can control the positional relationship between the pressure vessel 21 and the head 71 in the direction of the rotation axis of the pressure vessel 21 and the radial direction.

[0042] A method for manufacturing an aggregate of propellants 51, 52, and 53 by the propellant manufacturing apparatus 7 according to this embodiment will be described with reference to Fig. 6. Fig. 6 is a flowchart showing an example of a configuration of a method for manufacturing the propellants 51, 52, and 53 according to an embodiment. The flowchart in Fig. 6 includes a total of four steps from a first step S01 to a fourth step S04. Here, as an example, a case in which an aggregate of the propellants 51, 52, and 53 in Fig. 4A is manufactured will be described.

[0043] When the flowchart of Fig. 6 starts, the propellant manufacturing apparatus 7 may be initialized. As an example of the initialization, the control device 78, the head moving device 76, and the pressure vessel rotating device 77 may be initialized. As the initialization of the control device 78, data related to the shape of the propellant to be manufactured may be read, or a program for controlling the positional relationship between the pressure vessel 21 and the head 71 may be read. As the initialization of the head moving device 76, the head 71 may be placed at an initial position based on the program. As the initialization of the pressure vessel rotating device 77, the pressure vessel 21 may be placed at an initial position based on the program.

[0044] In a first step S01, the propellant manufacturing apparatus 7 prepares propellants 51, 52, and 53. In the case of FIG. 7A, first, a first propellant 51 is prepared in a container 73A. The first propellant 51 prepared in the container 73A may reach an outlet of the head 71 via a flow path 72. After the first step S01, a second step S02 is executed.

[0045] In a second step S02, the propellant manufacturing apparatus 7 stacks the propellants 51, 52, and 53 inside the pressure vessel 21. FIG. 7A is a cross-sectional view showing an example of a state of the propellant 51 in one step of a method for manufacturing the propellants 51, 52, and 53 according to an embodiment. The propellant manufacturing apparatus 7 rotates the pressure vessel 21 in a rotation direction 70 by the pressure vessel rotation device 77 while the head 71 continues to output the first propellant 51 so as to be in contact with the inner wall of the pressure vessel 21. By doing so, the first propellant 51 is arranged in a ring shape joined to the inner wall of the pressure vessel 21. In other words, the first propellant 51 is arranged in a ring-shaped space including the position of the head 71. The propellant manufacturing apparatus 7 further moves the head 71 parallel to the axis 10 while the head 71 continues to output the first propellant 51 and the pressure vessel rotation device 77 continues to rotate the pressure vessel 21. In this manner, the first propellant 51 is arranged in a cylindrical shape as an assembly of rings joined to the inner wall of the pressure vessel 21. When the head 71 moves from a position corresponding to the end face on the ignition device 22 side to a position corresponding to the end face on the nozzle 23 side, the first unit layer of the first propellant 51 is arranged to be joined to the inner wall of the pressure vessel 21.

[0046] The propellant manufacturing apparatus 7 then places the second unit layer of the first propellant 51 in contact with the inner surface of the first unit layer. To this end, the propellant manufacturing apparatus 7 moves the head 71 so as to approach the axis 10 by a distance corresponding to the thickness of the unit layer. While the head 71 is moving, the pressure vessel rotation device 77 may continue to rotate the pressure vessel 21. In addition, while moving the head 71 to the desired position, the head moving device 76 may move to a position sufficiently away from the first unit layer and then move to the desired position. Furthermore, the head 71 may stop outputting the first propellant 51 until the movement of the head 71 is completed.

[0047] When the movement of the head 71 is completed, the propellant production apparatus 7 stacks the second unit layer so as to be bonded to the inner side surface of the first unit layer. That is, similar to the case of the first unit layer, the pressure vessel 21 is rotated and the head 71 is moved while the first propellant 51 is output from the head 71, so that the second unit layer can be stacked so as to be bonded to the inner side surface of the first unit layer.

[0048] The propellant manufacturing apparatus 7 repeats stacking of unit layers of the first propellant 51 until a desired thickness is reached. The number of times this repetition is performed may be preset by a program. When the thickness of the first propellant 51 in the radial direction of the pressure vessel 21 reaches the desired thickness, a third step S03 is executed.

[0049] In the third step S03, the propellant manufacturing apparatus 7 judges whether all layers have been laminated. Here, since only the first layer made of the first propellant 51 has been laminated, the result of the judgment is "NO". In this case, after the third step S03, the first step S01 is executed again. Note that the case where the result of the judgment is "YES" will be described later.

[0050] When the first step S01 is performed for the second time, the propellant manufacturing apparatus 7 prepares the second propellant 52 in the container 73B this time. In other words, the container 73A used in the first first step S01 is replaced with the container 73B. At this time, the flow path 72 and the head 71 may be replaced so that the different propellants 51, 52 are not mixed. After the second first step S01, the second step S02 is performed for the second time.

[0051] When the second step S02 is performed for the second time, the propellant manufacturing apparatus 7 operates in the same manner as the first step S02. However, this time, the propellant manufacturing apparatus 7 stacks the second propellant 52 so as to be joined onto the surface of the first layer made of the first propellant 51. FIG. 7B is a cross-sectional view showing an example of a state of the propellants 51, 52 in one step of the manufacturing method of the propellants 51, 52, 53 according to an embodiment. As shown in FIG. 7B, the second layer made of the second propellant 52 has a cylindrical portion inscribed in the cylindrical first layer. Also, as shown in FIG. 7B, the second layer may have a flange portion that covers the end face of the cylindrical first layer on the nozzle 23 side and contacts the inner surface of the pressure vessel 21 in addition to the cylindrical portion. It can also be said that this flange portion is connected to the end face of the cylindrical portion of the second layer. This flange portion may be composed of the second propellant 52.

[0052] When the thickness of the second propellant 52 in the radial direction of the pressure vessel 21 reaches the desired thickness, the third step S03 is executed again. Here, the first layer made of the first propellant 51 and the second layer made of the second propellant 52 are stacked, but the third layer made of the third propellant 53 has not yet been stacked, so the result of the determination is "NO" again. Therefore, after the third step S03, the first step S01 is executed for the third time.

[0053] When the first step S01 is performed a third time, the propellant manufacturing apparatus 7 prepares the third propellant 53 in the container 73C this time. In other words, the container 73B used in the second first step S01 is replaced with the container 73C. At this time, the flow path 72 and the head 71 may be replaced so that the different propellants 52, 53 are not mixed. After the third first step S01, the third second step S02 is performed.

[0054] When the second step S02 is performed for the third time, the propellant manufacturing apparatus 7 operates in the same manner as the first or second second step S02. However, this time, the propellant manufacturing apparatus 7 stacks the third propellant 53 so as to be bonded onto the surface of the second layer made of the second propellant 52. FIG. 7C is a cross-sectional view showing an example of a state of the propellants 51, 52, 53 in one step of the manufacturing method of the propellants 51, 52, 53 according to an embodiment. As shown in FIG. 7C, the third layer made of the third propellant 53 has a cylindrical portion that is bonded to the inner surface of the cylindrical portion of the second layer. Also, as shown in FIG. 7C, the third layer may have a flange portion that is bonded to the end surface of the second layer on the nozzle 23 side and is also bonded to the inner surface of the pressure vessel 21 in addition to the cylindrical portion. In this case, the flange portion of the third layer is bonded to the flange portion of the second layer. It can also be said that this flange portion is connected to the end surface of the cylindrical portion of the third layer. This flange portion may be composed of a third propellant charge 53 .

[0055] When the thickness of the third propellant 53 in the radial direction of the pressure vessel 21 reaches the desired thickness, the third step S03 is executed for the third time. Since all layers have been laminated here, the result of the determination is "YES". Therefore, after the third step S03, the fourth step S04 is executed.

[0056] In the fourth step S04, the hardening device 79 completely hardens the entire stacked first propellant 51, second propellant 52, and third propellant 53 at once. This complete hardening is a process for finally hardening the propellants 51, 52, and 53, and may be performed by, for example, heating. In this case, the hardening device 79 may have a function of heating the propellants 51, 52, and 53 from the outside and / or inside of the pressure vessel 21. As a result, in the example shown in FIGS. 7A to 7C, the propellants 51, 52, and 53 shown in FIG. 4A are obtained.

[0057] When the fourth step S04 is completed, the flowchart in Fig. 6 ends. Note that the manufacturing process of the rocket motor 2 other than the propellant is not directly related to the features of this embodiment, so the illustration in the flowchart in Fig. 6 and detailed description thereof are omitted.

[0058] According to this embodiment, all the propellants 51, 52, and 53 are completely cured once as a whole, and therefore deterioration of the propellants 51, 52, and 53 due to curing can be suppressed compared to a case where some of the propellants are cured multiple times. Therefore, according to this embodiment, the propellants 51, 52, and 53 with higher performance can be manufactured.

[0059] The first propellant 51, the second propellant 52, and the third propellant 53 are integrated into one unit in the completely cured propellants 51, 52, and 53. Such a completely cured propellant may be called a propellant grain.

[0060] The restrictor 6 may be disposed on one or both end faces of the completely cured propellants 51, 52, and 53. The restrictor 6 prevents combustion of the portions of the surfaces of the propellants 51, 52, and 53 that are joined to the restrictor 6. As a modification of this embodiment, the restrictor 6 may be disposed on one or both end faces of the propellant before it is completely cured. To facilitate the arrangement of the restrictor 6, the end face of the pressure vessel 21 on the ignition device 22 side and / or the end face on the nozzle 23 side may be open until the restrictor 6 is arranged. As another configuration example, the restrictor 6 may not be provided on the surfaces of the propellants 51, 52, and 53.

[0061] Second embodiment In the above description, the first propellant 51, the second propellant 52, and the third propellant 53 constituting the first layer, the second layer, and the third layer, respectively, are prepared separately and supplied to the head 71. In this embodiment, two types of propellants having different burning rates are prepared and mixed in different ratios to supply three types of propellants to the head 71. As an example, the second propellant 52 may be generated by mixing the first propellant 51 and the third propellant 53 in an appropriate ratio.

[0062] FIG. 8A is a cross-sectional view showing an example of a state of the propellant 51 in one step of the method for producing the propellants 51, 52, and 53 according to an embodiment. In this embodiment, as shown in FIG. 8A, two containers 75A and 75B are prepared, and two types of propellants having different burning rates are prepared in each of them. A mixer 74 is provided downstream of the two containers 75A and 75B. The mixer 74 can generate a propellant having the same burning rate as the first propellant 51, for example, by mixing the two types of propellants sent from the two containers 75A and 75B at a predetermined ratio. A head 71 is connected downstream of the mixer 74 via a flow path 72. The containers 75A and 75B, the mixer 74, and the flow path 72 may be collectively referred to as a propellant supply device that supplies the propellants.

[0063] When the second step S02 in the flowchart shown in Fig. 6 is executed for the first time, the propellant manufacturing apparatus 7 can be modified as shown in Fig. 8A to realize the same operation as that in Fig. 7A. Here, the mixer 74 may mix the propellants under the control of the control device 78.

[0064] FIG. 8B is a cross-sectional view showing an example of a state of the propellants 51, 52 in one step of the method for producing the propellants 51, 52, 53 according to an embodiment. The propellant production apparatus 7 in FIG. 8B is configured similarly to the propellant production apparatus 7 in FIG. 8A. However, the ratio at which the mixer 74 mixes the two types of propellants sent from the two containers 75A, 75B is different. That is, the ratio in FIG. 8B is set so that the mixture has the same burning speed as the second propellant 52. When the second step S02 of the flowchart shown in FIG. 6 is executed for the second time, the propellant production apparatus 7 is changed as shown in FIG. 8B to realize the same operation as that in FIG. 7B.

[0065] FIG. 8C is a cross-sectional view showing an example of a state of the propellants 51, 52, and 53 in one step of the method for producing the propellants 51, 52, and 53 according to an embodiment. The propellant production apparatus 7 in FIG. 8C is configured similarly to the propellant production apparatus 7 in FIG. 8A. However, the ratio at which the mixer 74 mixes the two types of propellants sent from the two containers 75A and 75B is different. That is, the ratio in FIG. 8C is set so that the mixture has the same burning speed as the third propellant 53. When the second step S02 in the flowchart shown in FIG. 6 is executed for the third time, the propellant production apparatus 7 is changed as shown in FIG. 8C to realize the same operation as that in FIG. 7C.

[0066] In the above description, two types of propellants are mixed in the mixer 74, but this embodiment is not limited to this example. In other words, more propellants may be mixed in an appropriate ratio and supplied to the head 71.

[0067] (Third embodiment) In the above description, the propellant grain is manufactured by stacking three types of propellants 51, 52, and 53 with different burning rates, but this embodiment is not limited to this example. In other words, the propellant grain may be manufactured by stacking more types of propellants with different burning rates. As an example, by stacking different propellants in each unit layer, it is possible to manufacture a propellant grain in which the burning rate of the propellant grain changes substantially continuously from its inner surface to its outer surface.

[0068] Fig. 9 is a cross-sectional view showing an example of a configuration of a rocket motor 2 according to an embodiment. The rocket motor 2 in Fig. 9 is obtained by replacing the propellants 51, 52, and 53 of the rocket motor 2 in Fig. 4A with a propellant 54. In Fig. 9, the burning speed of the propellant 54 is represented by the darkness of the color. That is, the burning speed of the darker colored parts of the propellant 54 is faster, and the burning speed of the lighter colored parts is slower.

[0069] In other words, the propellant 54 in Fig. 9 is obtained by replacing the three types of propellants 51, 52, and 53 in Fig. 4A with many more types of propellants each having a different burning rate and stacking them. As an example, a plurality of unit layers each containing a plurality of propellants each having a different burning rate may be stacked in the order of the burning rates. Other details of the method and apparatus for manufacturing the rocket motor 2 in Fig. 9 are as described in the first and second embodiments.

[0070] In the rocket motor 2 of FIG. 9, the restrictor 6 is provided on the end face of the propellant 54 on the ignition device 22 side. In this case, as in the case of FIG. 4A, when the ignition device 22 ignites, the outer surface joined to the inner surface of the pressure vessel 21, the inner surface other than the end face joined to the restrictor 6, and the end face on the nozzle 23 side of the cylindrical propellant 54 start to burn. Propellant with a faster burning speed is arranged on the inner surface and the end face on the nozzle 23 side of the propellant 54. Also, the propellant with a slower burning speed is arranged in a position closer to the outer surface and farther from the end face on the nozzle 23 side of the propellant 54. Therefore, in the case of the propellant 54 of FIG. 9, the propellant with a faster burning speed burns at the start of burning when the area of ​​the burning surface is narrow, and the propellant with a slower burning speed burns when the area of ​​the burning surface becomes wider as the burning progresses, so that it is possible to level out the time change in the combustion pressure inside the pressure vessel 21.

[0071] Fig. 10 is a cross-sectional view showing an example of a configuration of a rocket motor 2 according to an embodiment. The rocket motor 2 in Fig. 10 is obtained by replacing the propellants 51, 52, and 53 of the rocket motor 2 in Fig. 4A with a propellant 55. In Fig. 10, as in Fig. 9, the burning speed of the propellant 55 is represented by the color depth.

[0072] The propellant 55 in FIG. 10 is also composed of a number of propellants each having a different burning rate, similarly to the case in FIG. 9. However, in the example in FIG. 10, unlike the cases in FIG. 9 and FIG. 4A, a plurality of propellants each having a different burning rate are mixed in each unit layer. The shape of any propellant contained in each unit layer may be a ring shape having rotational symmetry with respect to the axis 10 as the rotation axis, a tube shape which is an assembly of such rings, or a plurality of rings or tubes divided in the same unit layer. The propellant 55 thus configured can be manufactured by continuously changing the ratio at which the mixer 74 shown in FIG. 8A to FIG. 8C mixes two types of propellants at an appropriate timing while stacking one unit layer.

[0073] In the rocket motor 2 of FIG. 10, the restrictor 6 is not provided on the end surface of the propellant 55. In this case, when the ignition device 22 is ignited, the inner surface and both end surfaces of the cylindrical propellant 55 start to burn, except for the outer surface joined to the inner surface of the pressure vessel 21. Propellant with a faster burning speed is arranged on the inner surface and both end surfaces of the propellant 55. Also, propellant with a slower burning speed is arranged in a position of the propellant 55 closer to the outer surface and farther from the inner surface and both end surfaces. Therefore, in the case of the propellant 55 of FIG. 10, the propellant with a faster burning speed burns at the start of burning when the area of ​​the burning surface is narrow, and the propellant with a slower burning speed burns when the area of ​​the burning surface becomes wider as burning progresses, so that it is possible to level out the time change in the combustion pressure inside the pressure vessel 21.

[0074] Although the invention made by the inventor has been specifically described above based on the embodiment, it goes without saying that the present invention is not limited to the above embodiment and can be modified in various ways without departing from the gist of the invention. Furthermore, the respective features described in the above embodiment can be freely combined within the scope of technical compatibility.

[0075] The method of manufacturing the propellants 51, 52, 53, 54, and 55 described in each embodiment can be understood, for example, as follows.

[0076] (1) A method for producing propellants 51, 52, 53, 54, 55 according to a first embodiment is a method for producing propellants 51, 52, 53, 54, 55, which are propellant grains 51, 52, 53, 54, 55 having a first surface where combustion starts when ignited and a second surface joined to a wall surface 6, 21 that prevents combustion. This production method includes disposing a portion of a first propellant 51 having a first burning rate in a first space including a first position in contact with the second surface (S02), and disposing a portion of a second propellant 52 having a second burning rate faster than the first burning rate in a second space including a second position in contact with the first propellant 51 (S02). This production method further includes disposing a portion of a third propellant 53 having a third burning rate faster than the second burning rate in a third space including a third position in contact with the first surface (S02). This manufacturing method further includes completely curing the first propellant 51, the second propellant 52, and the third propellant 53 at once to generate propellant grains 51, 52, 53, 54, and 55 (S04).

[0077] The method for producing the propellants 51, 52, 53, 54, and 55 according to the first embodiment has the advantage that the three types of propellants 51, 52, and 53 having different burning rates can be completely hardened all at once after being placed.

[0078] (2) The method for producing the propellants 51, 52, 53, 54, 55 according to the second embodiment is the method for producing the propellants 51, 52, 53, 54, 55 according to the first embodiment, and further includes generating a first layer including a first propellant 51 along the wall surfaces 6, 21 (S02). The method for producing the propellants 51, 52, 53, 54, 55 according to the second embodiment further includes generating a second layer including a second propellant 52 so as to be laminated on the first layer (S02). The method for producing the propellants 51, 52, 53, 54, 55 according to the second embodiment further includes generating a third layer including a third propellant 53 on the first surface (S02).

[0079] The method for producing the propellants 51, 52, 53, 54, and 55 according to the second embodiment has the advantage that they can be produced using a so-called layered 3D printer.

[0080] (3) The method for producing the propellants 51, 52, 53, 54, 55 according to the third embodiment is the method for producing the propellants 51, 52, 53, 54, 55 according to the second embodiment, in which the wall surfaces 6, 21 include the inner surface of the pressure vessel 21, at least a portion of which is cylindrical. The propellant grains 51, 52, 53, 54, 55 are cylindrical, having an outer surface included in the second surface and an inner surface included in the first surface, and the outer surfaces of the propellant grains 51, 52, 53, 54, 55 are joined to the inner surface of the pressure vessel 21. At least a portion of the first layer is cylindrical, having an outer surface and an inner surface, and at least a portion of the outer surface of the first layer is at least a portion of the outer surface of the propellant grains 51, 52, 53, 54, 55. At least a portion of the third layer is cylindrical having an outer surface and an inner surface, and at least a portion of the inner surface of the third layer is at least a portion of the inner surfaces of the propellant grains 51, 52, 53, 54, 55.

[0081] The method for producing the propellants 51, 52, 53, 54, and 55 according to the third embodiment has the advantage that the propellant grains 51, 52, 53, 54, and 55 having a cylindrical shape that can be joined to the inner surface of the pressure vessel 21 can be produced.

[0082] (4) A manufacturing method of the propellants 51, 52, 53, 54, 55 according to the fourth aspect is a manufacturing method of the propellants 51, 52, 53, 54, 55 according to the third aspect, in which generating the second layer (S02) includes generating the second layer such that a surface of the first propellant 51 is bonded to the wall surfaces 6, 21 and the second propellant 52. In the manufacturing method of the propellants 51, 52, 53, 54, 55 according to the fourth aspect, generating the third layer includes generating the third layer such that a surface of the second propellant 52 is covered with the wall surfaces 6, 21, the first propellant 51 and the third propellant 53 (S02).

[0083] The manufacturing method of the propellants 51, 52, 53, 54, and 55 according to the fourth aspect has the advantage that the propellants 51, 52, 53, 54, and 55 can be manufactured so that the third layer made of the third propellant 53, the second layer made of the second propellant 52, and the first layer made of the first propellant 51 are burned in this order.

[0084] (5) A manufacturing method of the propellant 51, 52, 53, 54, 55 according to the fifth aspect is a manufacturing method of the propellant 51, 52, 53, 54, 55 according to any one of the second to fourth aspects, in which the wall surfaces 6, 21 include a surface of the restrictor 6, and further includes joining the restrictor 6 so as to cover an end face of the stacked first propellant 51.

[0085] The method for producing the propellants 51, 52, 53, 54, and 55 according to the fifth embodiment has the advantage that the combustion of the propellant grains 51, 52, 53, 54, and 55 can be controlled by disposing the restrictor 6.

[0086] (6) A method for producing the propellant 51, 52, 53, 54, 55 according to the sixth aspect is a method for producing the propellant 51, 52, 53, 54, 55 according to any one of the third to fifth aspects, and further includes generating a flange portion that is connected to one end face of the cylindrical second layer, contains the second propellant 52, is joined to one end face of the cylindrical first layer, and is joined to the inner surface of the pressure vessel 21.

[0087] The method for producing the propellants 51, 52, 53, 54, and 55 according to the sixth embodiment has an advantage that the combustion of the propellant grains 51, 52, 53, 54, and 55 can be controlled by providing the flange portion.

[0088] (7) A manufacturing method of the propellants 51, 52, 53, 54, and 55 according to the seventh aspect is a manufacturing method of the propellants 51, 52, 53, 54, and 55 according to any one of the third to sixth aspects, further including generating at least one of the first propellant 51, the second propellant 52, and the third propellant 53 by mixing propellants having different burning rates.

[0089] The method for producing the propellants 51, 52, 53, 54, and 55 according to the seventh embodiment has the advantage that a propellant having a desired burning rate can be prepared by mixing a plurality of propellants having different burning rates.

[0090] (8) A manufacturing method of propellants 51, 52, 53, 54, and 55 according to an eighth aspect is a manufacturing method of propellants 51, 52, 53, 54, and 55 according to any one of the third to seventh aspects, in which generating the first layer includes stacking a plurality of unit layers, each of which contains a plurality of propellants having different burning rates, in order of burning rate.

[0091] The method for producing the propellants 51, 52, 53, 54, and 55 according to the eighth embodiment has the advantage that it is possible to produce propellant grains whose burning speed changes substantially continuously from their inner surface to their outer surface.

[0092] (9) A manufacturing method for propellants 51, 52, 53, 54, and 55 according to a ninth aspect is a manufacturing method for propellants 51, 52, 53, 54, and 55 according to any one of the third to eighth aspects, in which generating the first layer includes stacking a plurality of unit layers, and each of the plurality of unit layers includes a plurality of propellants having different burning rates.

[0093] The method for producing the propellants 51, 52, 53, 54, and 55 according to the ninth embodiment has the advantage that a plurality of propellants having different burning rates can be arranged in any shape.

[0094] The propellant production apparatus 7 described in each embodiment can be understood, for example, as follows.

[0095] (1) The propellant manufacturing apparatus 7 according to the first embodiment is an apparatus for manufacturing propellants 51, 52, 53, 54, 55, which are propellant grains 51, 52, 53, 54, 55 having a first surface where combustion starts when ignited and a second surface joined to a wall surface 6, 21 that prevents combustion. The propellant manufacturing apparatus 7 according to the first embodiment includes a support device 77, propellant supply devices 73, 72, a head 71, a head moving device 76, a control device 78, and a hardening device 79. The support device 77 supports the wall surfaces 6, 21. The propellant supply devices 73, 72 supply the propellants 51, 52, 53 before hardening. The head 71 outputs the propellants 51, 52, 53 before hardening. The head 71 places the first propellant contained in the unhardened propellant in a space including a position in contact with the wall surface, and places the second propellant 52, which has a burning speed different from that of the first propellant 51, and the third propellant 53, which has a burning speed different from that of the first propellant 51 and the second propellant 52, contained in the unhardened propellants 51, 52, and 53, in a space including a predetermined position under the control of the control device 78. The head moving device 76 moves the head 71 to adjust the position of the head 71 with respect to the wall surfaces 6 and 21. The control device 78 controls the support device 77, the head 71, and the head moving device 76. The hardening device 79 completely hardens the entire first propellant 51, the second propellant 52, and the third propellant 53 at once to generate propellant grains 51, 52, 53, 54, and 55.

[0096] The propellant manufacturing apparatus 7 according to the first embodiment has an advantage that the three types of propellants 51, 52, and 53 having different burning rates can be hardened all at once after being placed.

[0097] The wall surfaces 6, 21 may be the surface of the restrictor 6 or the inner surface of the pressure vessel 21. The restrictor 6 and the pressure vessel 21 have the function of preventing combustion of the portions of the propellants 51, 52, 53, 54, 55 that are joined to the restrictor 6 and the pressure vessel 21, respectively.

[0098] (2) The propellant manufacturing apparatus 7 according to the second embodiment is the propellant manufacturing apparatus 7 according to the first embodiment. In the propellant manufacturing apparatus 7 according to the second embodiment, the wall surfaces 6, 21 include an inner surface of the pressure vessel 21 joined to the second surface of the propellant grain. The inner surface of the pressure vessel 21 includes a cylindrical inner surface having rotational symmetry with respect to the rotation axis 10. The support device 77 controls the relative positional relationship between the pressure vessel 21 and the head 71 in the circumferential direction of the pressure vessel 21 by rotating the pressure vessel 21 about the rotation axis 10 under the control of the control device 78. The head moving device 76 controls the relative positional relationship between the pressure vessel 21 and the head 71 in the radial direction of the pressure vessel 21 and the direction of the rotation axis under the control of the control device 78.

[0099] The support device 77 may be a pressure vessel rotation device 77. The support device 77 has a function of supporting and rotating the pressure vessel 21. The propellant production apparatus 7 according to the second embodiment has an effect of being able to operate as a so-called 3D printer by combining control of rotating the pressure vessel 21 and control of moving the head 71.

[0100] (3) A propellant manufacturing apparatus 7 according to a third embodiment is the propellant manufacturing apparatus 7 according to the first or second embodiment, and the propellant supply devices 73, 72 further include a plurality of containers 75A, 75B and a mixer 74. The plurality of containers 75A, 75B respectively supply a plurality of propellants having different burning rates. The mixer 74 mixes the plurality of propellants in a predetermined ratio under the control of a control device 78 to generate a propellant having a desired burning rate.

[0101] The propellant manufacturing apparatus 7 according to the third embodiment has an advantage that it is possible to prepare a propellant having a desired burning rate by mixing a plurality of propellants having different burning rates. [Explanation of symbols]

[0102] 1. Flying object 10 Axis 2. Rocket motor 21 Pressure Vessels 22 Ignition system 23 Nozzle 3. Control device 4. Payload 5. Propellant 50 Slots 51, 52, 53, 54, 55 Propellant 6 Restrictor 7. Propellant manufacturing equipment 70 Rotation Direction 71 Head 72 Flow Path 73A, 73B, 73C containers 74 Mixer 75A, 75B container 76 Head moving device 77 Pressure vessel rotation device (support device) 78 Control Device 79 Curing equipment 200A, 200B rocket motor

Claims

1. 1. A method for producing a propellant grain having a first surface at which combustion is initiated upon ignition and a second surface bonded to a wall surface that prevents said combustion, comprising: disposing a portion of a first propellant having a first burn rate in a first volume including a first location adjacent to the wall; disposing a portion of a second propellant having a second burn rate faster than the first burn rate in a second volume including a second location adjacent to the first propellant; disposing a portion of a third propellant having a third burn rate faster than the second burn rate in a third space including a third position in contact with the second propellant; completely curing the first propellant, the second propellant and the third propellant at once to generate the propellant grains; Including, The first propellant, the second propellant, and the third propellant are generated by mixing a plurality of propellants having different burning rates and in a slurry state in which materials are mixed, in a predetermined ratio. Also includes Propellant manufacturing method.

2. The method for producing a propellant according to claim 1, generating a first layer along the wall surface, the first layer including the first propellant; forming a second layer including the second propellant overlying the first layer; forming a third layer including the third propellant on the second layer; Also includes Propellant manufacturing method.

3. The method for producing a propellant according to claim 2, The wall surface includes an inner surface of a pressure vessel having at least a portion of a cylindrical shape; The propellant grain is cylindrical and has an outer surface included in the second surface and an inner surface included in the first surface, and the outer surface of the propellant grain is joined to the inner surface of the pressure vessel, At least a portion of the first layer is cylindrical having an outer surface and an inner surface, and at least a portion of the outer surface of the first layer is at least a portion of the outer surface of the propellant grain; At least a portion of the third layer is cylindrical having an outer surface and an inner surface, and at least a portion of the inner surface of the third layer is at least a portion of the inner surface of the propellant grain. Propellant manufacturing method.

4. The method for producing a propellant according to claim 3, Producing the second layer comprises: generating the second layer such that a surface of the first propellant is covered with the wall surface and the second propellant; Including, Producing the third layer comprises: generating the third layer so that a surface of the second propellant is covered with the wall surface, the first propellant, and the third propellant; Includes Propellant manufacturing method.

5. The method for producing a propellant according to claim 3 or 4, the wall surface includes a surface of a restrictor; The restrictor is disposed so as to be in contact with an end surface of the stacked first propellants. Also includes Propellant manufacturing method.

6. The method for producing a propellant according to any one of claims 3 to 5, generating a flange portion connected to one end surface of the cylindrical second layer, containing the second propellant, bonded to one end surface of the cylindrical first layer, and bonded to an inner surface of the pressure vessel; Also includes Propellant manufacturing method.

7. The method for producing a propellant according to any one of claims 3 to 6, Producing the first layer comprises: A plurality of unit layers each including a plurality of propellants having different burning rates are stacked such that the burning rate of the propellant grain decreases from the inner surface of the propellant grain toward the outer surface of the propellant grain. Includes Propellant manufacturing method.

8. The method for producing a propellant according to any one of claims 3 to 7, Producing the first layer comprises: Stacking multiple unit layers Including, Each of the plurality of unit layers includes a plurality of propellants having different burning rates. Propellant manufacturing method.

9. 1. An apparatus for producing a propellant grain having a first surface that initiates combustion upon ignition and a second surface bonded to a wall that prevents said combustion, comprising: A support device for supporting the wall surface; a propellant supply device for supplying unhardened propellant; A head for outputting the unhardened propellant; a head moving device that moves the head to adjust a position of the head with respect to the wall surface; a control device for controlling the support device, the head, and the head moving device; A plurality of containers each supplying a plurality of propellants having different burn rates and in the form of a slurry of mixed materials; a mixer for mixing the plurality of propellants in a predetermined ratio under the control of the controller to produce a propellant having a desired burn rate; Equipped with The head, under the control of the control device, disposes a first propellant contained in the unhardened propellant and having a first burning rate in a first space including a first position in contact with the wall surface, disposes a second propellant contained in the unhardened propellant and having a second burning rate faster than the first burning rate in a second space including a second position in contact with the first propellant, and disposes a third propellant contained in the unhardened propellant and having a third burning rate faster than the second burning rate in a third space including a third position in contact with the second propellant, Under the control of the control device, the plurality of propellants are mixed in the mixer in a predetermined ratio to generate the first propellant, the second propellant, and the third propellant; A hardening device for completely hardening the first propellant, the second propellant, and the third propellant at once to generate the propellant grains. Further equipped Propellant manufacturing equipment.

10. The propellant manufacturing apparatus according to claim 9, the wall surface includes an inner surface of a pressure vessel joined to the second surface of the propellant grain; The inner surface of the pressure vessel includes a cylindrical inner surface having rotational symmetry with respect to a rotation axis, the support device controls a relative positional relationship between the pressure vessel and the head in a circumferential direction of the pressure vessel by rotating the pressure vessel around the rotation axis under the control of the control device; The head moving device controls the relative positional relationship between the pressure vessel and the head in the radial direction of the pressure vessel and in the direction of the rotation axis under the control of the control device. Propellant manufacturing equipment.

Images