JP6883817B2 - Rocket motor - Google Patents

Description

The present invention relates to a rocket motor that ignites after being launched by an external force such as the combustion pressure of a propellant.

As a rocket motor of this type, for example, there is one described in Patent Document 1. The rocket motor described in Patent Document 1 constitutes a rocket, a solid propellant formed in a tubular shape is loaded in a motor case, and a central hole of the solid propellant communicates with a rocket nozzle. It has a support tube. The central support tube forms a gap with the inner hole of the solid propellant.

The above rocket motor (rocket) is loaded into the launcher together with the propellant, launched by the propellant, and then ignites the solid propellant. At this time, the rocket motor compresses the solid propellant in the axial direction when it receives a large acceleration at the time of launch, and at the same time, expands it radially by the amount of the gap, and supports the solid propellant by the central support tube. Then, when the force in the axial direction of the rocket motor stops, the solid propellant returns to its original shape and forms a gap between its inner hole and the central support pipe, enabling the inner surface combustion of the solid propellant. To do.

Tokukousho No. 48-26640

However, the conventional rocket motor as described above allows the solid propellant to be deformed by the acceleration at the time of launch, and has a structure in which the central support tube remains even after the solid propellant is ignited. For this reason, in the conventional rocket motor, in order to achieve both the function of protecting the solid propellant from acceleration and the function of withstanding the combustion temperature, the central support tube needs to have sufficient rigidity and heat resistance, and the manufacturing cost is high. There is a problem that there is a risk of increasing or decreasing the structural mass ratio. The decrease in the structural mass ratio of the rocket motor has a great effect on the flight distance.

The present invention has been made by paying attention to the above-mentioned conventional problems, and in a rocket motor that ignites after being launched by an external force, it is possible to protect the solid propellant from the acceleration at the time of launch and to reduce the manufacturing cost. It is an object of the present invention to provide a rocket motor capable of reducing and improving the structural mass ratio.

The rocket motor according to the present invention is a rocket motor that ignites after being launched by an external force, and includes a motor case, a solid propellant loaded in the motor case, a rocket nozzle provided at the tail of the motor case, and the inside of the motor case. It is equipped with an ignition device that is placed on the axis of the rocket nozzle. Then, in the rocket motor, the ignition device is arranged on the axis of the rocket nozzle and inserted into the inner hole of the solid propellant , and the head is opened in the vicinity of the head in the motor case. It is characterized by having a conical portion that is continuous with the tail of the tube portion and closes the rocket nozzle, and an igniter arranged inside the support tube portion, and is detachably coupled to the motor case. ..

Since the rocket motor according to the present invention employs an ignition device provided with a support tube portion, a conical portion and an igniter, it is solid against the force acting on the solid propellant due to its acceleration when launched by an external force. Prevents deformation of the propellant.

In addition, when the rocket motor ignites the igniter of the ignition device after being launched by an external force, the high-temperature gas generated by this ignites into the motor case from the head of the support tube, and the solid propellant is ignited. Will be done. After that, the rocket motor separates the ignition device from the motor case by the pressure of the combustion gas of the solid propellant, and at the same time, opens the rocket nozzle, and ejects the combustion gas from the rocket nozzle to fly. In this way, since the rocket motor disengages the ignition device after igniting the solid propellant, it is sufficient that the ignition device has the minimum rigidity and heat resistance, and the solid propellant burns well after the disengagement. It is done in.

In this way, the rocket motor according to the present invention can protect the solid propellant from the acceleration at the time of launch in the rocket motor that ignites after launching by an external force, and can reduce the manufacturing cost and improve the structural mass ratio. Can be realized.

It is sectional drawing of the rocket which shows one Embodiment of the rocket motor which concerns on this invention. It is sectional drawing which shows the state at the time of launch (A) by the external force of the rocket shown in FIG. 1, at the time of the start of flight (B), and after ignition of a solid propellant (C). It is a front view (A) and the sectional view (B) of the tail of a rocket which show other embodiment of the rocket motor which concerns on this invention.

The rocket motor R shown in FIG. 1 is applied to the propulsion device of the rocket A. The projectile A is provided with a shell 52 loaded with an explosive charge 51, a fuze 53 at the head of the shell 52, and a rocket motor R connected to the tail of the shell 52.

The rocket motor R is arranged on the axis of the rocket nozzle 3 inside the motor case 1, the solid propellant 2 loaded in the motor case 1, the rocket nozzle 3 provided at the tail of the motor case 1, and the motor case 1. It is provided with an ignition device 4.

The motor case 1 has a loading space 1A open to the head side, and by connecting to the tail of the shell 52, the loading space 1A is sealed, and the outer surface thereof is smooth with the outer surface of the shell 52. It is continuous with. Further, the motor case 1 has a central protruding portion 1B and a skirt portion 1C surrounding the outer periphery of the protruding portion 1B at the tail portion, and a rocket nozzle communicating with the loading space 1A on the axis of the protruding portion 1B. 3 is formed. The rocket nozzle 3 in the illustrated example has a shape in which the inner diameter on the head side is constant and the inner diameter on the tail side gradually increases.

The solid propellant 2 has an inner combustion type grain shape having an inner hole 2A on the axis, and is, for example, a composite propellant. The composite propellant has higher performance than the double base propellant, but has a small elastic modulus and is easily deformed. The type of solid propellant is not particularly limited in the rocket motor R of the present invention, but as will be described later, the rocket motor R exhibits a more excellent effect when the above composite propellant is used.

Further, in the rocket motor R, heat insulating materials 5 are provided on the tail surface of the shell 52, which is the inner surface of the motor case 1, the inner surface of the tail of the motor case 1, and the inner peripheral surface of the rocket nozzle 3, respectively.

The ignition device 4 is arranged on the axis of the rocket nozzle 3, that is, on the axis of the rocket motor R because there is only one rocket nozzle 3 in this embodiment. The ignition device 4 is arranged in the inner hole 2A of the solid propellant 2, and is continuous with the support tube portion 6 whose head is open in the motor case 1 and the tail of the support tube portion 6 and closes the rocket nozzle 3. The conical portion 7 to be formed and the ignition charge 8 arranged inside the support tube portion 6 are provided, and are detachably coupled to the motor case 1.

The ignition device 4 can be molded from various materials such as metal and fiber reinforced plastic. The support tube portion 6 has a length extending from the portion of the rocket nozzle 3 on the head side to the vicinity of the head of the motor case 1, and is inserted into the inner hole 2A of the solid propellant 2. The conical portion 7 corresponds to a portion on the tail side of the rocket nozzle 3, that is, a portion in which the inner diameter gradually increases, and closes the rocket nozzle 3. The ignition charge 8 is arranged in the tail portion of the support tube portion 6, and in this embodiment, the ignition charge 8A is provided on the tail side and the main charge 8B on the head side thereof.

Further, the ignition device 4 is detachably coupled to the motor case 1 by a shear pin 9 that engages with the rocket nozzle 3 and the conical portion 7. Further, the rocket motor R has an ignition space 10 in the motor case 1 on the head side of the support tube portion 6 of the solid propellant 2 and the ignition device 4. The head of the support tube portion 6 is open to the ignition space 10.

The rocket A equipped with the rocket motor R is loaded into the launch tube C together with the propellant as shown in FIG. 2, and is launched by the combustion pressure of the propellant as an external force as shown in FIG. 2 (A). To. At this time, the rocket A is subjected to a large acceleration indicated by a large arrow in FIG. 2 (A).

At this time, in the rocket motor R, a compressive load in the axial direction indicated by a small arrow in FIG. 2 (A) is applied to the solid propellant 2, and the compressive load causes the solid propellant 2 to expand in the radial direction toward the tail side. A deforming force acts. On the other hand, since the rocket motor R includes an ignition device 4 provided with a support tube portion 6, a conical portion 7, and an igniting agent 8, even if it receives an acceleration at the time of launch, it resists the above-mentioned force. It restrains the solid propellant 2 and prevents the solid propellant 2 from being deformed. Therefore, even if a easily deformable composite propellant is used as the solid propellant 2, deformation of the solid propellant 2 due to acceleration at the time of launch can be reliably prevented.

Further, as shown in FIG. 2B, the rocket motor R ignites the ignition charge 8 of the ignition device 4 after being launched by an external force. In the rocket motor R of this embodiment, the delay agent 8A is ignited by the heat of the combustion gas of the propellant, and the main charge 8B is ignited after a lapse of a certain period of time.

As a result, in the rocket motor R, the high-temperature gas generated by the combustion of the main charge 8B passes through the inside of the support tube portion 6 and flows into the ignition space 10 in the motor case 1 from the opened head. , The solid propellant 2 is ignited. At this time, the solid propellant 2 is an inner surface combustion type having an inner hole 2A, but end surface combustion also occurs due to the ignition space 10.

After that, as shown in FIG. 2C, the rocket motor R cuts the shear pin (see FIG. 1) 9 by the pressure of the combustion gas generated by the combustion of the solid propellant 2, and the igniter from the motor case 1. 4 is separated rearward, and at the same time, the rocket nozzle 3 is opened, and combustion gas is ejected from the rocket nozzle 3 to fly. At this time, in the rocket motor R, the head side of the rocket nozzle 3 has a constant inner diameter, but since the inner hole 2A is expanded by the inner surface combustion of the solid propellant 2, the head side of the rocket nozzle 3 quickly throats the nozzle. Become a department.

As described above, even if the rocket motor uses a easily deformable composite propellant as the solid propellant 2, it surely prevents the solid propellant 2 from being deformed due to the acceleration at the time of launch, and also to the solid propellant 2. Since the ignition device 4 is disengaged after the ignition of the above, it is sufficient that the ignition device 4 has the minimum rigidity and heat resistance, and the solid propellant 2 is burned well after the disengagement.

In this way, the rocket motor R can protect the solid propellant 2 from the acceleration at the time of launch in the rocket motor that ignites after launching by an external force, and can reduce the weight, reduce the manufacturing cost, and reduce the structural mass ratio. Improvements can be achieved. The improvement of the structural mass ratio can also contribute to an increase in the flight distance (range).

Further, since the rocket motor R has an ignition space 10 on the head side in the motor case 1, the solid propellant 2 is ignited after adopting the ignition device 4 that contacts the inner hole 2A. Can be performed smoothly and reliably. Moreover, since the rocket motor R has a high protective function of the solid propellant 2 as described above, it is extremely useful when the solid propellant 2 is a composite propellant.

Further, the rocket motor R can increase the amount of the solid propellant 2 by adopting the ignition device 4. That is, in the conventional rocket motor in which the central support tube is arranged on the axis inside the motor, it is necessary to make the diameter of the central support tube larger than the throat diameter of the nozzle in order to provide the flow path of the combustion gas. On the other hand, in the rocket motor R, after ignition, the ignition device 4 including the support tube portion 6 is detached. Therefore, the diameter of the support tube portion 6 should be reduced to the same size as the throat diameter of the rocket nozzle 3. Can be done.

As a result, as described above, the rocket motor R can suppress the deformation of the solid propellant 2 due to the acceleration at the time of launch, and also realizes a small diameter of the support tube portion 6 to increase the amount of the solid propellant 2. Can be made to.

FIG. 3 is a diagram illustrating another embodiment of the rocket motor according to the present invention. The same components as those in the previous embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The rocket motor R of this embodiment is provided with a plurality of (four in the illustrated example) rocket nozzles 3 at the tail of the motor case 1. The number of rocket nozzles is not particularly limited. The rocket motor R includes each ignition device 4 on the axis of each rocket nozzle 3 inside the motor case 1.

In the rocket motor R having the above configuration, after launching by an external force (see FIG. 2), the solid propellant 2 is ignited by the ignition device 4 in the ignition space 10 in the motor case 1, and the solid propellant 2 is ignited. The ignition device 4 is separated rearward by the pressure of the combustion gas of the above, and at the same time, the rocket nozzle 3 is opened to fly.

Similar to the previous embodiment, the rocket motor R reliably prevents the solid propellant 2 from being deformed due to the acceleration at the time of launch even if a composite propellant that is easily deformed into the solid propellant 2 is used. Since the ignition device 4 is detached after the solid propellant 2 is ignited, it is sufficient that the ignition device 4 has the minimum rigidity and heat resistance, and the solid propellant 2 is burned well after the solid propellant 2 is ignited. As a result, the rocket motor R can protect the solid propellant 2 from the acceleration at the time of launch, reduce the manufacturing cost, and improve the structural mass ratio.

Further, in the case of the rocket motor R provided with a plurality of rocket nozzles 3 as in this embodiment, the ignition device 4 is arranged only in the selected rocket nozzle 3, and the nozzles can be separated into the other rocket nozzles 3. It is also possible to provide a closure. However, if the ignition devices 4 are arranged in all the rocket nozzles 3 as shown in the illustrated example, the operation reliability is naturally high.

The configuration of the rocket motor according to the present invention is not limited to the above embodiment, and the configuration can be appropriately changed without departing from the gist of the present invention, and other than the rocket. Of course, it can also be applied to the propulsion device of the projectile.

A rocket R rocket motor 1 motor case 2 solid propellant 2A inner hole 3 rocket nozzle 4 ignition device 6 support tube part 7 conical part 8 ignition agent 9 shear pin 10 ignition space

Claims (4)

A rocket motor that ignites after being launched by an external force.
It is equipped with a motor case, a solid propellant loaded in the motor case, a rocket nozzle provided at the tail of the motor case, and an ignition device arranged inside the motor case on the axis of the rocket nozzle.
The ignition device is arranged on the axis of the rocket nozzle and inserted into the inner hole of the solid propellant , and the head is opened near the head in the motor case, and the tail of the support pipe is continuous. The rocket motor is characterized in that it includes a conical portion that closes the rocket nozzle and an igniter arranged inside the support tube portion, and is detachably coupled to the motor case.
The rocket motor according to claim 1, wherein an ignition space is provided in the motor case on the head side of the support tube portion of the solid propellant and the ignition device. The rocket motor according to claim 1 or 2, wherein the solid propellant is a composite propellant. A rocket comprising the rocket motor according to any one of claims 1 to 3 as a propulsion device.

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