JP3209869B2 - Solid rocket motor and solid propellant injection method for solid rocket motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid rocket motor used as an upper rocket motor having a grain formed by direct filling and hardening by injecting a solid propellant into a motor case and a solid propellant in the motor case. The present invention relates to a method for injecting a solid propellant of a solid rocket motor used when a grain is formed by injection and a direct filling hardening method.

[0002]

2. Description of the Related Art Conventionally, as the above-mentioned solid rocket motor, there is one shown in FIGS. 4 and 5, for example.

As shown partially in FIG. 4, a solid rocket motor 51 includes a motor case 52, a heat insulator 53 attached to the inside of the motor case 52, and a grain 54 filled inside the heat insulator 53. And a tail end 5 of the grain 54 provided near the tail end of the heat insulator 53.
A relief boot 55 is provided to adhere to the periphery of 4a, and a nozzle (not shown) is attached to the tail opening of the motor case 52.

As shown in the enlarged circle of FIG. 4, the relief boot 55 is formed so as to branch off from the heat insulator 53, and as shown in FIG. During cooling of the grains 54 formed by the direct-fill hardening method in which heat is hardened, the grains 54 move from the state shown by the imaginary line to the state shown by the solid line together with the tail-side end 54a of the grain 54, and the thermal stress generated by this heat shrinkage Has been reduced.

When the slurry 54 is injected into the motor case 52 to form the grains 54, for example, as shown in FIG. 6, the end portion 55 a of the relief boot 55 is protected during the injection operation. The solid propellant 56 is injected while the end 60a of the relief boot 55 is pulled toward the tail opening side of the motor case 52 through the protective film 60 with the membrane 60 attached. Slurry solid propellant 56 is prevented from flowing between 55 and heat insulator 53, and end 55a of relief boot 55 is prevented from falling into solid propellant 56 and hardening as it is. I have. The protective film 60 is removed after the solid propellant 56 is cured and the grains 54 are formed.

The above-mentioned solid rocket motor 51 is described in the second edition Aerospace Engineering Handbook, pages 932 to 933, published by Maruzen Co., Ltd. on September 30, 1992.

[0007]

However, in such a conventional solid rocket motor 51, the function of the relief boot 55 for relieving the thermal stress caused by the thermal contraction of the grains 54 during the operation of injecting the slurry-like solid propellant 56. Since the protective film 60 irrelevant to the above needs to be mounted on the relief boot 55, extra steps and material costs are required for mounting and removing the protective film 60.

Further, the protective film 60 is not completely attached to the end 55a of the relief boot 55,
In the case where the end portion 55a is not sufficiently drawn due to the zero, the inflow of the slurry solid propellant 56 between the above-described relief boot 55 and the heat insulator 53 or the solidity of the end portion 55a in the relief boot 55 There is a problem that problems such as embedding into the propellant 56 may occur, and solving these problems has been a conventional problem.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems. In addition to being able to reliably alleviate the thermal stress caused by heat shrinkage during cooling of the grains, the present invention has been made in view of the above. And material costs,
It is an object of the present invention to provide a solid rocket motor capable of improving workability and a method for injecting a solid propellant for the solid rocket motor.

[0010]

The invention according to claim 1 of the present invention comprises a motor case, a heat insulator attached to the inside of the motor case, and a solid propellant formed inside the heat insulator. In a solid rocket motor provided with a grain, the heat insulator has a heat-insulating material laminated adhesive structure, and a release film is interposed between the heat insulator and the heat insulating material at the tail-side end of the grain or at a position in the vicinity thereof. A structure in which a case-side heat-insulating portion and a relief boot portion that can be separated are formed, and an end of the case-side heat-insulating portion and an end of the relief boot portion are adhered over the entire circumference, and a vent hole is provided in the relief boot portion. The configuration of the solid rocket motor is used as means for solving the above-mentioned conventional problems.

According to a second aspect of the present invention, there is provided a solid body including a motor case, a heat insulator attached to the inside of the motor case, and a grain formed of a solid propellant formed inside the heat insulator. In a rocket motor, the heat insulator has a heat-insulating material laminated adhesive structure, and a case-side heat insulator capable of being separated from each other by interposing a release film between the heat insulator and the heat insulating material at or near the tail end of the grain. And a relief boot portion, wherein the end of the case-side heat insulating portion and the end of the relief boot portion are partially bonded in the circumferential direction. Means to solve the above problems.

On the other hand, the invention according to claim 3 of the present invention provides:
When a solid propellant is injected into the inside of the motor case through a heat insulator to form a grain, the heat insulator is made into a heat insulating material laminated adhesive structure, and when the heat insulating material is laminated and adhered to each other, the tail side of the grain is formed. A case-side heat-insulating portion and a relief that can be separated from each other and that each end is adhered over the entire circumference by interposing a release film between the heat-insulating material and the heat-insulating material at or near the end position. In addition to forming a boot portion and forming a vent hole in the relief boot portion, the solid propellant is injected. The solid propellant injection method for the solid rocket motor solves the above-mentioned conventional problems. And means for doing so.

According to a fourth aspect of the present invention, when a solid propellant is injected into a motor case through a heat insulator to form a grain, the heat insulator has a heat-insulating material laminated adhesive structure, and the heat-insulating material is formed. When laminating and adhering to each other, a release film is interposed between a heat insulating material and a heat insulating material at or near a portion where the tail side end of the grain is located, and can be separated from each other and each end A case-side heat-insulating portion and a relief boot portion are bonded together, and a non-adhesion portion is partially formed in the circumferential direction at an adhesion portion between the end of the case-side heat insulation portion and the end of the relief boot portion. After the formation, the solid propellant is injected, and the solid propellant injection method of the solid rocket motor is a means for solving the above-mentioned conventional problems.

[0014]

[0015]

[0016]

According to the first and second aspects of the present invention, when the slurry-like solid propellant is injected into the motor case, the end of the case-side heat insulating portion and the end of the relief boot portion are connected to each other. Since it is adhered, problems such as the flow of solid propellant between the case-side heat insulating part and the relief boot part can be prevented without using the protective film that was conventionally required. The material cost can be reduced, and the injection workability can be improved.

[0017] Claims 1 and 2 of the present invention.
In the invention according to the present invention, since the above-described configuration is adopted,
When the formed grains are cooled by injecting the solid propellant into the motor case, the difference in linear expansion coefficient (coefficient of thermal expansion) and rigidity between the motor case and the solid propellant causes
Although the grain whose outer peripheral side is fixed to the motor case undergoes a large thermal contraction, thermal stress (grain internal working stress) is generated.
Since the relief boot moves away from the heat insulating part on the case side and moves in the direction of deformation along with the tail-side end of the grain, which deforms greatly, the thermal stress is reduced, and the safety factor of the mechanical strength of the grain Will be sufficiently secured.

At this time, the space between the relief boot portion separated from the case-side heat-insulating portion and the case-side heat-insulation portion is released to the atmosphere to avoid a substantially vacuum state. Since it is separated with almost no resistance, the relief function of the relief boot portion can be further improved.

According to the third and fourth aspects of the present invention, since the above-described structure is employed, the injection of the solid propellant into the motor case does not require a protective film which has been conventionally used. A situation in which the solid propellant flows between the side heat insulating portion and the relief boot portion does not occur. As a result, man-hours and material costs are reduced, and injection workability is improved. Then, when the grains formed by the injection of the solid propellant are cooled, as in the conventional case, the relief boot portion separates from the case-side heat insulating portion, and the thermal stress generated by the large thermal contraction of the grains is reduced. At this time, the relief boot part is separated from the case-side heat-insulating part with almost no resistance because the space between the relief-boot part and the case-side heat-insulating part is separated from the case-side heat-insulating part. In addition, thermal stress relaxation by the relief boot portion is more reliably performed.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment of a solid rocket motor and a solid propellant injection method for the solid rocket motor according to the present invention.

As shown in FIG. 1, the solid rocket motor 1 has a motor case 2 made of a titanium alloy and a fiber reinforced plastic, a heat insulator 10 attached to the inside of the motor case 2, and an inner side of the heat insulator 10. Is provided in the tail opening of the motor case 2,
The nozzle 4 is connected to its subsonic contraction part 4a and throat part 4b.
Is buried in the motor case 2 and attached.

As shown in an enlarged manner in FIG. 2, the heat insulator 10 is formed by laminating and bonding rubber-based thin plate heat insulators 10A and 10B. The heat insulator 10 is located at the tail end 3a of the grain 3 or a portion located in the vicinity thereof. Include rubber-based thin-plate insulation materials 10A, 10B
A case-side heat-insulating portion 11 and a relief boot portion 12 which are formed so as to be separated from each other by interposing a release film 5 therebetween are provided, and the end portion 11a of the case-side heat-insulating portion 11 and the relief boot portion are provided. The end 12a of 12 is adhered over the entire circumference. In this case, the relief boot portion 12 is provided with a small-diameter vent hole 12b.

The grains 3 are formed by a direct filling hardening method in which a solid propellant 6 in the form of a slurry is injected into the motor case 2 and thermally hardened at about 50 to 60 ° C. Except for the surface, all are adhered to the heat insulator 10. When the grain 3 is cooled to room temperature, it thermally contracts from the state shown by the imaginary line in FIGS. 1 and 2 to the state shown by the solid line. It moves away from the heat insulating portion 11 in the deformation direction together with the tail end 3a of the grain 3.

In the solid rocket motor 1, when forming the grains 3, the slurry-like solid propellant 6 is used.
Is injected into the motor case 2 when the rubber-based heat insulating materials 10A and 10B are laminated and adhered to each other, the rubber-based heat insulating material 10A in the portion where the tail end 3a of the grain 3 is located or in the vicinity thereof. , 10B, the release film 5 is sandwiched between the case-side heat-insulating portions 11.
And the relief boot portion 12, the ends 11 a and 12 a are adhered to each other over the entire circumference, and a small-diameter vent hole 12 b is formed in the relief boot portion 12. Inject.

Therefore, since the end 11a of the case-side heat-insulating portion 11 and the end 12a of the relief boot portion 12 are adhered, the solid propellant 6 enters between the case-side heat-insulating portion 11 and the relief boot portion 12. Since the occurrence of a situation such as inflow is avoided, the number of steps and material cost can be reduced as compared with the conventional case requiring a protective film, and the injection workability is also improved.

In the solid rocket motor 1, when the grains 3 are cooled, due to differences in linear expansion coefficient and rigidity between the motor case 2 and the solid propellant 6, the outer periphery of the motor case 2 Grain 3 with fixed side
Thermal stress is generated by large thermal contraction, but the relief boot portion 12 separates from the case-side heat insulating portion 11 and moves in the deformation direction together with the tail-side end portion 3a of the grain 3, which is particularly largely deformed freely. As a result, the thermal stress is surely alleviated, and the safety factor of the mechanical strength in the grains 3 is sufficiently secured. In this embodiment, the small diameter ventilation holes 12b are formed in the relief boot portion 12. Therefore, when the relief boot portion 12 is separated from the case-side heat-insulating portion 11, the space between the relief boot portion 12 and the case-side heat-insulating portion 11 is released to the atmosphere via the ventilation hole 12b.
Since the relief boot portion 12 is separated from the case side heat insulating portion 11 with almost no resistance, the relief boot portion 12
Will further improve the thermal stress relaxation function.

FIG. 3 shows another embodiment of the solid rocket motor and the solid propellant injection method for the solid rocket motor according to the present invention.

The solid rocket motor 2 according to this embodiment
1 and the solid propellant injection method of the solid rocket motor is different from that of the previous embodiment in that the thin rubber-based heat insulating materials 10A and 10B for injecting the slurry-like solid propellant 6 into the motor case 2 are laminated. In the previous embodiment, at the time of bonding to each other, the end portions 1 of the case-side heat insulating portion 11 and the relief boot portion 12 formed at or near the portion where the tail-side end 3a of the grain 3 is located.
1a and 12a are adhered to each other over the entire circumference, and a small-diameter ventilation hole 12b is formed in the relief boot portion 12. On the other hand, in this embodiment, the tail-side end 3a of the grain 3 is located. This is in that the end 11a of the case-side heat-insulating portion 11 formed at or near the portion and the end 22a of the relief boot portion 22 are bonded via bonding portions 22c provided at a plurality of positions in the circumferential direction.

That is, also in the solid rocket motor 21 according to this embodiment, the end 11
a and the end 22a of the relief boot portion 22
2c, the case-side heat insulating portion 11
The solid propellant 6 is prevented from flowing into the space between the relief boot portion 22 and the relief boot portion 22, and when the grain 3 is cooled, the adhesive portion is formed between the relief boot portion 22 and the case-side heat insulating portion 11. Non-adhesion part 2 formed between 22c
Since the relief boot portion 22 is released from the case-side heat-insulating portion 11 with little resistance, the relief boot portion 22 moves in the deformation direction together with the tail-side end portion 3a of the grain 3 because the relief boot portion 22 is released to the atmosphere via the 2d. The thermal stress due to the thermal shrinkage of the substrate is surely alleviated.

[0031]

As described above, according to the first aspect of the present invention,
In addition, in the invention according to claim 2, since the slurry-type solid propellant is injected into the interior of the motor case, the case-side heat insulating portion and the relief boot portion can be used without using a protective film which is conventionally required. It is possible to prevent a situation such as inflow of a solid propellant from flowing into the space, and it is possible to reduce man-hours and material costs and to improve injection workability. When the grain is cooled, the relief boot part moves away from the case-side heat-insulating part and moves in the direction of deformation along with the tail-side end of the grain, which undergoes large free deformation due to thermal shrinkage, so that thermal stress is reliably reduced. A remarkable advantage is that relaxation is possible.

Further, according to the first and second aspects of the present invention, the space between the relief boot portion separated from the case-side heat-insulating portion and the case-side heat-insulating portion can be released to the atmosphere. Since the relief boot portion is separated from the case-side heat-insulating portion with almost no resistance, a remarkably excellent effect that the thermal stress relaxation function of the relief boot portion can be further improved is brought about.

Further, claims 3 and 4 of the present invention.
In the invention according to the invention, since the solid propellant is injected into the motor case, the solid propellant is injected between the case-side heat-insulating portion and the relief boot portion without the need for the conventionally used protective film. It is possible to prevent the inflow of the drug from occurring, and as a result, without impairing the function of relieving the thermal stress caused by the large thermal contraction when the grains are cooled.
It has a remarkably excellent effect that the man-hour and material cost can be reduced and the injection workability can be improved, and in addition, the space between the relief boot portion and the case-side heat insulating portion can be opened to the atmosphere. Therefore, a remarkably excellent effect that thermal stress relaxation by the relief boot portion can be further enhanced is brought about.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing an embodiment of a solid rocket motor according to the present invention.

FIG. 2 is an enlarged sectional explanatory view of a relief boot portion in the solid rocket motor of FIG. 1;

FIG. 3 is an enlarged front explanatory view of a relief boot portion showing another embodiment of the solid rocket motor according to the present invention.

FIG. 4 is a partially sectional explanatory view showing a conventional solid rocket motor.

FIG. 5 is an explanatory partial cross-sectional view showing a state where grains are thermally compressed in the solid rocket motor of FIG. 4;

6 is an enlarged sectional explanatory view of a relief boot showing a state in which a solid propellant is injected into the solid rocket motor of FIG. 4 to form grains.

[Explanation of symbols]

 1, 21 solid rocket motor 2 motor case 3 grain 3a tail side end 6 solid propellant 10 heat insulator 10A, 10B rubber-based thin plate heat insulating material 11 case side heat insulating portion 11a end of case side heat insulating portion 12, 22 relief boot portion 12a, 22a End of relief boot portion 12b Vent hole 22c Adhesive portion 22d Non-adhesive portion

Continued on the front page (72) Inventor Sakae Miyatani 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. (72) Inventor Haruhito Hanno 2 Takara-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. (56) References JP-A-7-54710 (JP, A) JP-A-52-61615 (JP, A) JP-A-5-256196 (JP, A) Japanese Utility Model Laid-Open No. 62-21456 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F02K 9/24 F02K 9/36

Claims (4)

(57) [Claims] 1. A solid rocket motor comprising a motor case, a heat insulator affixed inside the motor case, and a grain made of a solid propellant molded inside the heat insulator, wherein the heat insulator is thermally insulated. Material laminated adhesive structure,
Forming a case-side heat-insulating portion and a relief boot portion that can be separated from each other by interposing a release film between a heat-insulating body and a heat-insulating material at the tail-side end of the grain or a position in the vicinity thereof, and forming the case-side heat insulating portion. A solid rocket motor characterized in that an end of the relief boot is adhered to the end of the relief boot portion over the entire circumference, and a vent is provided in the relief boot portion. 2. A solid rocket motor comprising a motor case, a heat insulator affixed inside the motor case, and a grain made of a solid propellant molded inside the heat insulator, wherein the heat insulator is thermally insulated. Material laminated adhesive structure,
Forming a case-side heat-insulating portion and a relief boot portion that can be separated from each other by interposing a release film between a heat-insulating body and a heat-insulating material at the tail-side end of the grain or a position in the vicinity thereof, and forming the case-side heat insulating portion. A solid rocket motor characterized in that the end of the solid rocket and the end of the relief boot portion are partially adhered in the circumferential direction. 3. When a solid propellant is injected into the inside of a motor case through a heat insulator to form grains, the heat insulator has a heat-insulating material laminated bonding structure, and when heat insulating materials are laminated and bonded to each other, A case in which a release film is interposed between a heat insulating material and a heat insulating material in a portion where the tail end of the grain is located or in the vicinity thereof, and can be separated from each other, and each end is bonded over the entire circumference. A solid propellant injection method for a solid rocket motor, comprising: forming a side heat insulating portion and a relief boot portion; forming a vent hole in the relief boot portion; and then injecting the solid propellant. 4. Injecting a solid propellant into the inside of a motor case through a heat insulator to form a grain, the heat insulator has a heat-insulating material laminated bonding structure, and when heat insulating materials are laminated and bonded to each other, A case-side heat-insulating portion in which a release film is interposed between the heat-insulating material and the heat-insulating material at or near the portion where the tail-side end of the grain is located, and which can be separated from each other and each end is adhered to each other. And a relief boot portion, and a solid propellant is injected after forming a non-adhesion portion in a circumferential direction at an adhesion portion between an end portion of the case-side heat insulation portion and an end portion of the relief boot portion. A solid propellant injection method for a solid rocket motor.