JP6307345B2 - Multi-pulse rocket motor and manufacturing method thereof - Google Patents

Description

  The present invention relates to a multi-pulse rocket motor having two or more propellants and injecting propulsion gas from a common injection nozzle and a method for manufacturing the same.

  A multi-pulse rocket motor is a rocket motor that contains a plurality of solid propellants and generates thrust by burning each solid propellant at different timings. Such multi-pulse rocket motors are disclosed in, for example, Patent Documents 1 to 6.

Japanese National Patent Publication No. 11-503802 JP 2008-280967 A JP 2012-255362 A JP 2013-7327 A JP2013-29100A JP2013-24034A

The multi-pulse rocket motor includes a plurality of solid propellants, a plurality of ignition devices, a single pressure vessel, and an injection nozzle.
The plurality of solid propellants are partitioned from each other by a heat-resistant diaphragm member, and are embedded adjacently in the same pressure vessel. Each solid propellant is ignited and burned at different timings by an ignition device provided for each solid propellant.

It is necessary that the solid propellant (hereinafter referred to as the second propellant) ignited later does not ignite while the solid propellant (hereinafter referred to as the first propellant) ignited first is burning.
Therefore, the unignited second propellant is partitioned from the combustion flame of the first propellant by a highly heat-resistant diaphragm member so that it does not ignite.

Thereafter, the second propellant that has not been ignited is ignited at different timings. At this time, the diaphragm member that partitions the second propellant from the first propellant is broken by the combustion pressure, and the combustion gas is injected from the injection nozzle.
Further, when the diaphragm member is broken by the combustion pressure, it is necessary that the diaphragm member is broken at a preset weak portion and the fragments do not scatter.

  For this reason, the diaphragm member has increased the strength of the fixed portion (front end portion and rear end portion) to the pressure vessel where stress is particularly high.

For example, in the pulse rocket motor of Patent Document 4, the second propellant has a hollow cylindrical shape fixed to the inner surface of the distal end portion of the pressure vessel. The inner surface and the rear end surface of the hollow cylinder-shaped second propellant are covered with an integrally formed diaphragm member, and the front end portion and the rear end portion of the diaphragm member are vulcanized and bonded to a metal diaphragm holding metal fitting.
The diaphragm holding metal fitting at the rear end includes a convex portion extending radially inward into the outer peripheral surface of a hollow disk-shaped diaphragm member (hereinafter referred to as “rear end diaphragm”) covering the rear end surface of the second propellant. The convex portion is vulcanized and bonded to the rear end diaphragm, and the outer peripheral portion of the diaphragm holding metal fitting is coupled to the pressure vessel with a bolt or the like.

When the diaphragm member is broken by the combustion pressure, the rear end diaphragm swells rearward due to the combustion pressure, and the outer peripheral portion bends rearward.
At this time, since the diaphragm holding metal fitting is made of a metal having no flexibility, there is a possibility that the outer peripheral portion of the rear end diaphragm subjected to the combustion pressure bends at the tip of the convex portion of the diaphragm holding metal fitting and breaks from the portion. It was. In this case, the rear end membrane has fallen from the base, the combustion form becomes unstable, the performance of the rocket motor is lowered, and the injection nozzle may be clogged.

  Moreover, since the diaphragm holding metal fitting is made of metal, the pressure vessel to which it is attached is also made of metal, and the weight of the diaphragm holding fitting, the pressure vessel, and the bolts connecting them increases, and the overall weight of the pulse rocket motor increases. In addition, there is a problem that the bonding structure becomes complicated.

  The present invention has been developed to solve the above-described problems. That is, the object of the present invention is to increase the strength of the outer peripheral portion of the diaphragm member covering the rear end surface of the propellant when the propellant fixed to the inner surface of the front end portion of the pressure vessel is ignited and the diaphragm member is broken by the combustion pressure. An object of the present invention is to provide a multi-pulse rocket motor that can prevent breakage from the part and reduce the overall weight, and a method for manufacturing the same.

According to the present invention, the hollow cylinder-shaped first propellant whose outer peripheral surface is covered with the first heat insulating material and provided in the subsequent stage in the pressure vessel,
A hollow cylinder-shaped second propellant having a front surface and an outer peripheral surface covered with a second heat insulating material and provided in a preceding stage in the pressure vessel;
A diaphragm member that covers an inner surface and a rear end surface of the second propellant and has heat resistance, airtightness, and flexibility to withstand a combustion flame of the first propellant and the second propellant,
The diaphragm member includes a hollow cylindrical cylindrical membrane portion whose front end is fixed to the pressure vessel and extends rearward along the inner surface of the second propellant, and a second propellant integrally connected to the rear end of the cylindrical membrane portion. A hollow disc-shaped ring membrane portion extending radially outward along the rear end surface of
The ring film portion has a rear end holding portion sandwiched between the first heat insulating material and the second heat insulating material at an outer end thereof,
A high-tensile cloth material is integrally vulcanized and molded inside the ring film part from the rear end holding part to the radially inner side,
The high-tensile cloth material has flexibility capable of following the deformation of the ring film portion due to the combustion pressure of the second propellant, and has a tensile strength that can withstand the tensile force generated by the combustion pressure. A featured multi-pulse rocket motor is provided.

The first heat insulating material and the second heat insulating material each have a cylindrical first concave portion and a second concave portion that extend inward in the axial direction at the boundary surfaces thereof,
The rear end holding portion has a cylindrical first convex portion and a second convex portion that are fitted and bonded to the first concave portion and the second concave portion, respectively.

The high-tensile cloth material is a plurality of unidirectional cloth materials in which fibers are arranged in the same direction,
Each unidirectional cloth member is uniformly arranged in the circumferential direction inside the ring film part from the rear end holding part to the radially inner side, and the fiber direction is oriented in the radial direction.

  The said diaphragm member has a weak part weaker than another part in the one part.

The diaphragm member is made of EPDM rubber,
The high tension cloth material is carbon fiber or glass fiber.

According to the present invention, the hollow cylinder-shaped first propellant, the outer peripheral surface of which is covered with the first heat insulating material and provided in the rear stage in the pressure vessel,
A hollow cylinder-shaped second propellant having a front surface and an outer peripheral surface covered with a second heat insulating material and provided in a preceding stage in the pressure vessel;
Preparing a diaphragm member covering the inner surface and the rear end surface of the second propellant and having heat resistance, airtightness and flexibility to withstand the combustion flame of the first propellant and the second propellant;
The diaphragm member includes a hollow cylindrical cylindrical membrane portion extending rearward along the inner surface of the second propellant, and a radial direction along the rear end surface of the second propellant integrally connected to the rear end of the cylindrical membrane portion. A hollow disc-shaped ring membrane portion extending outwardly,
High-strength cloth material is integrally vulcanized and molded at the outer end of the ring membrane portion to provide a rear end holding portion,
The high-tensile cloth material is flexible enough to follow the deformation of the ring membrane due to the combustion pressure of the second propellant, and has a tensile strength that can withstand the tensile force generated by the combustion pressure. ,
There is provided a method of manufacturing a multi-pulse rocket motor, wherein a front end portion of the cylindrical membrane portion is fixed to a pressure vessel, and the rear end holding portion is sandwiched between a first heat insulating material and a second heat insulating material. The

  According to the apparatus and method of the present invention, since the diaphragm member covering the inner surface and the rear end surface of the second propellant is provided, a plurality of solid propellants (the first propellant and the second propellant) are supplied at different timings. It can be burned to generate thrust.

  Further, the diaphragm member is composed of a cylindrical membrane portion and a ring membrane portion, and the rear end holding portion of the ring membrane portion incorporates a high-tensile cloth material integrally molded. The high-tensile cloth material has flexibility capable of following the deformation of the ring film portion due to the combustion pressure of the second propellant, and has a tensile strength that can withstand the tensile force generated by the combustion pressure. Therefore, the second propellant fixed to the inner surface of the front end of the pressure vessel is ignited and the rear end holding the rear end surface of the second propellant is retained until a part of the diaphragm member (for example, the fragile portion) is broken by the combustion pressure. It is possible to increase the strength of the outer peripheral portion of the portion and prevent breakage from the outer peripheral portion.

  Furthermore, according to the configuration of the present invention, the rear end holding portion is made of rubber having high heat resistance (for example, EPDM rubber) and a high-tensile cloth material, so that the rear end holding portion can be reduced in weight compared to a metal. Further, since the rear end holding part is not fixed to the pressure vessel, the pressure vessel can be made of a lightweight fiber reinforced plastic (for example, CFRP). Therefore, the overall weight of the rocket motor can be reduced.

As described above, the conventional metal diaphragm holding metal fitting is not required, the structure weight is reduced, the structure is simplified, and the number of parts can be reduced.
Further, since the rear end holding portion of the ring membrane portion incorporates a high-strength cloth material integrally molded, there is no fear that the ring membrane portion falls off during the combustion of the second propellant.

1 is an overall configuration diagram of a multi-pulse rocket motor according to the present invention. It is the elements on larger scale of FIG. It is a single-piece | unit side view of a diaphragm member. FIG. 3 is a partially enlarged view of FIG. 2. It is operation | movement explanatory drawing of the multipulse rocket motor by this invention.

  A preferred embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

FIG. 1 is an overall configuration diagram of a multi-pulse rocket motor M according to the present invention.
In this figure, the multi-pulse rocket motor M of the present invention includes a pressure vessel 10, a first propellant 20, a second propellant 22, and a diaphragm member 30 (thermal barrier).
In this figure, ZZ is the central axis of the multi-pulse rocket motor M.

  The pressure vessel 10 includes a hollow cylindrical motor case 12 containing a first propellant 20 and a second propellant 22, a head closing body 14 for closing a front portion (left side in the drawing) of the motor case 12, and a motor. It has the injection nozzle 18 attached to the rear part (right side in the figure) of the case 12.

  In this example, the motor case 12 is made of CFRP (epoxy resin reinforced with carbon fiber) obtained by a filament winding method.

In this example, the head closing body 14 is made of metal such as titanium, maraging steel, D6AC steel, or chromium molybdenum steel.
A first igniter 15 is attached on the central axis of the head closing body 14, and the first propellant 20 is ignited at an arbitrary timing and burned. The combustion gas G1 (see FIG. 5) of the first propellant 20 is ejected rearward (rightward in the drawing) from the injection nozzle 18 through the central opening of the first propellant 20, and generates thrust.

  The diaphragm member 30 covers the inner surface and the rear end surface of the second propellant 22, and prevents ignition of the second propellant 22 by the combustion gas G1 of the first propellant 20. The diaphragm member 30 is preferably made of EPDM rubber (ethylene / propylene / diene rubber: Rubber, Ethylene-) having heat resistance, airtightness and flexibility that can withstand the combustion flame of the first propellant 20 and the second propellant 22. (Propylene-Diene).

The first propellant 20 has a hollow cylindrical shape, and the outer peripheral surface thereof is covered with a first heat insulating material 21 and is provided in the subsequent stage in the pressure vessel 10. The first propellant 20 is a composite propellant that burns first. The entire inner hole of the first propellant 20 may have a circular cross section, or a light beam cross section such as a star shape may be formed at an arbitrary position such as rearward from the center in the front-rear direction.
The first propellant 20 may be composed of a plurality of propellants connected in series along the Z axis.

The second propellant 22 has a hollow cylindrical shape, and the front surface and the outer peripheral surface thereof are covered with the second heat insulating material 23 and are provided in the front stage in the pressure vessel 10. The second propellant 22 is a composite propellant that burns after the first propellant 20. The inner hole cross section of the second propellant 22 is circular, and communicates with the inner hole of the first propellant 20 via the diaphragm member 30.
The first propellant 20 and the second propellant 22 may be the same type of composite propellant or different.

  The first heat insulating material 21 and the second heat insulating material 23 are preferably made of EPDM rubber having heat resistance and airtightness that can withstand the combustion flame of the first propellant 20 and the second propellant 22.

A second igniter 16 is built in the front end portion (head closing body 14) of the pressure vessel 10, and the second propellant 22 is ignited and burned at an arbitrary timing. The diaphragm member 30 is configured such that a fragile portion 33 described later breaks before the other portion due to the combustion pressure of the combustion gas G2 of the second propellant 22.
The combustion gas G2 of the second propellant 22 is ejected rearward (rightward in the drawing) from the ejection nozzle 18 through the fracture portion of the diaphragm member 30, and generates thrust.

FIG. 2 is a partially enlarged view of FIG.
In this figure, the motor case 12 includes a CFRP inner tube 12a wound directly around the first heat insulating material 21 and the second heat insulating material 23, and a CFRP outer tube 12b wound around the outer side of the inner tube 12a. It consists of.
With this configuration, the pressure vessel 10 that can withstand the combustion pressure of the first propellant 20 and the second propellant 22 can be made lighter than metal.

In FIG. 2, the head closing body 14 includes a ring-shaped base 14a (boss) fixed to the front end of the motor case 12, a ring-shaped closure 14b fixed inside the base 14a, and a central hole of the closure 14b. And a first igniter 15 inserted into the.
Moreover, the closure 14b has the 2nd igniter 16 incorporated in the ignition chamber B which is a ring-shaped space comprised between the nozzle | cap | die 14a.

  The ring-shaped portion C of the closure 14b that partitions the ignition chamber B and the second propellant 22 is provided with a plurality of ignition holes 17a penetrating in the axial direction at intervals in the circumferential direction. The ignition hole 17a has a function of communicating the ignition flame generated in the second igniter 16 to the second propellant 22 side.

The base 14 a has a flange portion D. The flange portion D extends inward in the radial direction between the second heat insulating material 23 located on the front surface of the second propellant 22 and the ignition hole 17a. Further, the inner end of the flange portion D is a tapered inner surface or a cylindrical inner surface, and an annular gap 17 b is formed between the outer end surface of the diaphragm member 30.
Further, a cylindrical gap 19 is formed between the outer surface of the diaphragm member 30 and the inner surface of the second propellant 22.

  With this configuration, the ignition flame generated in the second igniter 16 can be communicated with the cylindrical gap 19 via the ignition hole 17a and the annular gap 17b, and the second propellant 22 can be ignited and burned from the inner surface.

FIG. 3 is a single side view of the diaphragm member 30.
2 and 3, the diaphragm member 30 has a hollow cylindrical cylindrical membrane portion 32 and a hollow disc-shaped ring membrane portion 34.

  The front end portion of the hollow cylindrical cylindrical membrane portion 32 is fixed to the head closing body 14 of the pressure vessel 10 and extends rearward along the inner surface of the second propellant 22. A hollow cylindrical fixing ring 31 is attached to the front end of the cylindrical membrane portion 32 by integral vulcanization molding. A front surface of the fixing ring 31 is provided with a plurality of screw holes, and is fixed to the closure 14b of the head closing body 14 by a plurality of bolts screwed into the screw holes.

  The hollow disk-shaped ring membrane portion 34 is integrally connected to the rear end of the cylindrical membrane portion 32 and extends radially outward along the rear end surface of the second propellant 22. In this example, the ring film portion 34 is orthogonal to the Z axis, but may be oblique.

  Moreover, the diaphragm member 30 has the weak part 33 weaker than another part in the one part. The fragile portion 33 is a part of the cylindrical membrane portion 32 or the ring membrane portion 34, is more fragile than the other portions (the cylindrical membrane portion 32 and the ring membrane portion 34), and is generated when the second propellant 22 is ignited. Due to the combustion pressure, it breaks before other parts.

FIG. 4 is a partially enlarged view of FIG.
In FIG. 4, the ring film portion 34 has a rear end holding portion 35 sandwiched between the first heat insulating material 21 and the second heat insulating material 23 at the outer end thereof.
The 1st heat insulating material 21 and the 2nd heat insulating material 23 have the cylindrical 1st recessed part 21a and the 2nd recessed part 23a which are respectively extended in the axial direction in the boundary surface. The rear end holding portion 35 includes a cylindrical first convex portion 35a and a second convex portion 35b that are fitted and bonded to the first concave portion 21a and the second concave portion 23a, respectively.
The depths of the first recess 21 a and the second recess 23 a and the lengths of the first protrusion 35 a and the second protrusion 35 b have an adhesive area that can withstand the combustion pressure acting on the rear end holding portion 35.

A high-tensile cloth material 36 is integrally vulcanized and molded inside the ring film portion 34 from the rear end holding portion 35 to the inside in the radial direction. The high-tensile cloth material 36 has a flexibility that can follow the deformation of the ring film portion 34 due to the combustion pressure of the second propellant 22 and can withstand the tensile force generated by the combustion pressure of the second propellant 22. Has strength.
The position of the radially inner end of the high-tensile cloth material 36 is set so that the strength of the outer peripheral portion of the rear end holding portion 35 can be increased.
The high-tensile cloth material 36 is preferably carbon fiber, Kevlar fiber (registered trademark) , or glass fiber.

The high-tensile cloth material 36 is a plurality of unidirectional cloth materials in which fibers are arranged in the same direction.
The unidirectional cloth members are equally arranged in the circumferential direction inside the ring film part 34 from the rear end holding part 35 to the inner side in the radial direction, and the fiber direction is oriented in the radial direction.

Next, a manufacturing method of the above-described multi-pulse rocket motor M will be described.
(1) First, the first propellant 20, the second propellant 22, and the diaphragm member 30 described above are prepared.
The motor case 12 of the pressure vessel 10 is preferably made of CFRP by a filament winding method.
(2) The rear end holding portion 35 is provided by integrally vulcanizing and molding the above-described high-tensile cloth material 36 at the outer end of the ring membrane portion 34.
(3) The front end portion of the cylindrical membrane portion 32 is fixed to the head closing body 14 of the pressure vessel 10, and the rear end holding portion 35 of the ring membrane portion 34 is sandwiched between the first heat insulating material 21 and the second heat insulating material 23. To do.
By the manufacturing method described above, the strength of the rear end holding portion 35 can be increased, and the weight of the rear end holding portion 35 and the pressure vessel 10 can be reduced.

FIG. 5 is an operation explanatory view of the multi-pulse rocket motor M according to the present invention.
In this figure, (A) and (B) show during combustion of the first propellant 20 and after combustion, and (C) and (D) show when the second propellant 22 is ignited and during combustion.

  In FIG. 5A, the first igniter 15 is ignited, whereby the combustion of the first propellant 20 is started. Combustion occurs from the inner peripheral surface of the inner hole of the first propellant 20, and the combustion gas G1 is injected into the atmosphere through the injection nozzle 18. As a result, the multi-pulse rocket motor M obtains thrust by the first pulse.

  At this time, since the inner surface and the rear end surface of the second propellant 22 are covered with the diaphragm member 30, the ignition flame when the first igniter 15 is ignited and the combustion gas G1 of the first propellant 20 are not invaded. Absent.

  As shown in FIG. 5B, the first pulse ends when all of the first propellant 20 has finished burning.

  In FIG. 5C, when the second igniter 16 is ignited at an arbitrary timing, the ignition flame generated in the second igniter 16 is separated from the outer surface of the diaphragm member 30 via the ignition hole 17a and the annular gap 17b. It flows into the cylindrical gap 19 between the inner surface of the propellant 22. The ignition flame that has flowed into the cylindrical gap 19 ignites and burns the second propellant 22 from the inner surface to generate combustion gas G2. Due to the combustion pressure of the combustion gas G2, the cylindrical membrane portion 32 of the diaphragm member 30 is deformed inward and the ring membrane portion 34 is deformed rearward.

In FIG. 5D, the fragile portion 33 (see FIG. 4) is broken before the other portion due to the combustion pressure when the second propellant 22 is ignited. After this fracture, the cylindrical gas film portion 32 is buckled axially by the combustion gas G2, the ring film portion 34 is bent backward, and the combustion gas G2 is injected into the atmosphere through the injection nozzle 18.
At this time, the surface of the diaphragm member 30 is burned down by the combustion gas G2, but the thickness is set so as to leave a certain amount or more of a layer that does not burn in order to prevent falling off. Therefore, without the diaphragm member 30 falling off, the second propellant 22 continues to burn, all of the second propellant 22 burns, and the second pulse ends.

  According to the apparatus and method of the present invention described above, since the diaphragm member 30 covering the inner surface and the rear end surface of the second propellant 22 is provided, the first propellant 20 and the second propellant 22 are burned at different timings. Can generate thrust.

  The diaphragm member 30 includes a cylindrical membrane portion 32 and a ring membrane portion 34, and a rear end holding portion 35 of the ring membrane portion 34 incorporates a high-tensile cloth material 36 that is integrally vulcanized and molded. The high-tensile cloth member 36 has flexibility capable of following the deformation of the ring film portion 34 due to the combustion pressure of the second propellant 22 and has a tensile strength that can withstand the tensile force generated by the combustion pressure. Therefore, the strength of the outer peripheral portion of the rear end holding portion 35 can be increased and the fracture from the outer peripheral portion can be prevented before the second propellant 22 is ignited and the fragile portion 33 is broken by the combustion pressure.

  Furthermore, according to the present invention, the rear end holding portion 35 is made of a highly heat-resistant rubber (for example, EPDM rubber) and the high-tensile cloth material 36, so that the rear end holding portion 35 can be reduced in weight compared to a metal. . Moreover, since the rear end holding part 35 is not fixed to the pressure vessel 10, the pressure vessel 10 can be made of a lightweight fiber reinforced plastic (for example, CFRP). Therefore, the overall weight of the rocket motor can be reduced.

As described above, the conventional metal diaphragm holding metal fitting is not required, the structure weight is reduced, the structure is simplified, and the number of parts can be reduced.
Further, since the rear end holding portion 35 of the ring membrane portion 34 incorporates the high-strength cloth material 36 integrally molded, the fear that the ring membrane portion 34 may fall off during the combustion of the second propellant 22 may be eliminated. it can.

  In addition, this invention is not limited to embodiment mentioned above, Of course, a various change can be added in the range which does not deviate from the summary of this invention.

M multi-pulse rocket motor, B ignition chamber, C ring-shaped part,
D flange part, G1, G2 combustion gas, 10 pressure vessel, 12 motor case,
12a inner pipe, 12b outer pipe, 14 head closure, 14a mouthpiece (boss),
14b closure, 15 first igniter, 16 second igniter,
17a ignition hole, 17b annular gap, 18 injection nozzle, 19 cylindrical gap,
20 1st propellant, 21 1st heat insulating material, 21a 1st recessed part, 22 2nd propellant,
23 second heat insulating material, 23a second recess, 30 diaphragm member, 31 fixing ring,
32 cylindrical film part, 33 weak part, 34 ring film part, 35 rear end holding part,
35a 1st convex part, 35b 2nd convex part, 36 high tensile cloth material

Claims (6)

A hollow cylinder-shaped first propellant whose outer peripheral surface is covered with a first heat insulating material and is provided in a subsequent stage in the pressure vessel;
A hollow cylinder-shaped second propellant having a front surface and an outer peripheral surface covered with a second heat insulating material and provided in a preceding stage in the pressure vessel;
A diaphragm member that covers an inner surface and a rear end surface of the second propellant and has heat resistance, airtightness, and flexibility to withstand a combustion flame of the first propellant and the second propellant,
The diaphragm member includes a hollow cylindrical cylindrical membrane portion whose front end is fixed to the pressure vessel and extends rearward along the inner surface of the second propellant, and a second propellant integrally connected to the rear end of the cylindrical membrane portion. A hollow disc-shaped ring membrane portion extending radially outward along the rear end surface of
The ring film portion has a rear end holding portion sandwiched between the first heat insulating material and the second heat insulating material at an outer end thereof,
A high-tensile cloth material is integrally vulcanized and molded inside the ring film part from the rear end holding part to the radially inner side,
The high-tensile cloth material has flexibility capable of following the deformation of the ring film portion due to the combustion pressure of the second propellant, and has a tensile strength that can withstand the tensile force generated by the combustion pressure. A featured multi-pulse rocket motor. The first heat insulating material and the second heat insulating material each have a cylindrical first concave portion and a second concave portion that extend inward in the axial direction at the boundary surfaces thereof,
2. The multi-piece according to claim 1, wherein the rear end holding portion includes a cylindrical first convex portion and a second convex portion that are fitted and bonded to the first concave portion and the second concave portion, respectively. Pulse rocket motor. The high-tensile cloth material is a plurality of unidirectional cloth materials in which fibers are arranged in the same direction,
Each of the unidirectional cloth members is uniformly arranged in the circumferential direction inside the ring film part from the rear end holding part to the radially inner side, and the fiber direction is oriented in the radial direction. Item 4. The multi-pulse rocket motor according to Item 1.   The multi-pulse rocket motor according to claim 1, wherein the diaphragm member has a weakened portion weaker than other portions in a part thereof. The diaphragm member is made of EPDM rubber,
The high tension cloth material, the multi-pulse rocket motor according to claim 1, wherein the carbon fibers or glass fibers. A hollow cylinder-shaped first propellant whose outer peripheral surface is covered with a first heat insulating material and is provided in a subsequent stage in the pressure vessel;
A hollow cylinder-shaped second propellant having a front surface and an outer peripheral surface covered with a second heat insulating material and provided in a preceding stage in the pressure vessel;
Preparing a diaphragm member covering the inner surface and the rear end surface of the second propellant and having heat resistance, airtightness and flexibility to withstand the combustion flame of the first propellant and the second propellant;
The diaphragm member includes a hollow cylindrical cylindrical membrane portion extending rearward along the inner surface of the second propellant, and a radial direction along the rear end surface of the second propellant integrally connected to the rear end of the cylindrical membrane portion. A hollow disc-shaped ring membrane portion extending outwardly,
High-strength cloth material is integrally vulcanized and molded at the outer end of the ring membrane portion to provide a rear end holding portion,
The high-tensile cloth material is flexible enough to follow the deformation of the ring membrane due to the combustion pressure of the second propellant, and has a tensile strength that can withstand the tensile force generated by the combustion pressure. ,
A method of manufacturing a multi-pulse rocket motor, wherein a front end portion of the cylindrical membrane portion is fixed to a pressure vessel, and the rear end holding portion is sandwiched between a first heat insulating material and a second heat insulating material.

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