JPH0715277B2 - Solid rocket motor - Google Patents

Description

Detailed Description of the Invention [Object of the Invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid rocket motor used for a flying vehicle that changes its direction immediately after being vertically launched. (Prior Art) In recent years, small missiles and other projectiles launched from the ground or ships have been designed with vertical The method of firing to has been adopted. This type of projectile uses a solid rocket motor as a power source and requires a rapid direction change (initial turning) immediately after launch, and therefore is equipped with thrust direction control means such as jet vanes and movable nozzles.
Moreover, it is necessary to obtain a large initial speed and stable thrust. Therefore, in the solid rocket motor, a propellant grain having a neutral combustion pattern in which thrust is almost constant over time, for example, an end surface combustion type, an inner surface combustion type having a star-shaped inner hole, or an inner hole And a propellant grain such as an inner and outer surface combustion type having an outer peripheral space. Propellant grains with such a neutral burning pattern
For example, it is described on page 647 of “Aerospace Engineering Handbook, Supplement,” edited by The Japan Aerospace Society, published by Maruzen in April 1983. (Problems to be Solved by the Invention) However, in the solid rocket motor as described above, there is the following problem in the flying body that changes the direction immediately after being vertically launched. As shown in FIG. 9, the projectile R fired vertically performs thrust direction control according to the flight direction as indicated by the arrow in the figure at the position a immediately after the launch, and the thrust direction after the start of turning. Is returned in the axial direction (b, c). However, since the thrust of the solid rocket motor has already reached near the maximum value at the start of turning of the flying object R, the tail portion is raised by the vertical acceleration at the position d during turning, and this is corrected. Therefore, the thrust direction is controlled upward. After that, the flying body R returns the thrust direction to the axial direction again, and while appropriately controlling the thrust direction, the attitude is gradually changed to be horizontal (e to h) and the turning ends. In other words, the conventional solid rocket motor has a problem that it causes a swinging motion of the flying vehicle R during turning, resulting in energy loss until the initial turning is completed. The problem was to solve the problem. (Object of the Invention) The present invention has been made by paying attention to the above-mentioned conventional problems, and is a solid rocket motor used for a flying vehicle that changes the direction immediately after being vertically launched. It is an object of the present invention to provide a solid rocket motor capable of preventing the energy loss of the solid state and improving the performance in terms of speed and input altitude.

[Constitution of the invention]

(Means for Solving the Problems) A solid rocket motor according to the present invention is a solid rocket motor used for a flying vehicle that changes direction immediately after being vertically launched, in a propellant grain, from the launch to the completion of initial turning. For the burning area of propellant consumed during
The above-mentioned configuration is a means for solving the conventional problems by providing a cavity portion for increasing the combustion area of the propellant after the completion of the initial turning to an area where the maximum thrust can be generated. In the embodiment of the solid rocket motor according to the present invention, the amount of propellant during the combustion area from the initial stage to the increase in the first stage is set to the amount consumed during the time when the initial turning of the projectile is completed. It is also possible to use a propellant grain having a structure in which a central hole is provided along the axis, and a cavity portion for increasing the combustion area is provided on the outer peripheral side of the central hole in a state of being separated from the central hole. In this case, the amount of propellant between the central hole and the cavity can be the amount consumed during the time when the initial turning of the projectile is completed. Providing a propellant grain with a structure in which the central hole is used as a cavity for increasing the combustion area by providing an inner combustion section with a central hole and a solid end combustion section at the tail of this inner combustion section. Can, in this case, the end face combustion section It is possible to propellant volume having a configuration in which the initial turning of the projectile is to the amount consumed in the time to complete. (Operation of the Invention) In the solid rocket motor according to the present invention, the thrust increases stepwise as the combustion area increases stepwise with the lapse of time after ignition. The solid rocket motor maintains a small thrust within a predetermined time after ignition, prevents an excessive acceleration in the vertical direction from being applied to the projectile during the initial turn after vertical launch, and causes the turning motion to cause energy loss. After that, the space is smooth, and the combustion area of the propellant is increased by the cavity, so that the thrust is increased to the maximum value and the projectile continues to be propelled. (Example) Hereinafter, the present invention will be described with reference to the drawings. 1 to 5 are views for explaining an embodiment of the present invention. That is, in the solid rocket motor 1 shown in FIG. 1, a propellant grain 3 is loaded in a cylindrical chamber 2, and a nozzle 5 is further provided at a tail portion of a small diameter portion 4 constituting a tail portion of the chamber 2. . The small diameter portion 4 and the nozzle 5
A jet vane device 7 as thrust direction control means is housed between the outer wall plate 6 and the outer wall plate 6 continuous with the main body of the chamber 2. The jet vane device 7 includes a controller 8 having a built-in computer, an actuator 9 operated by a signal from the controller 8, and a blade 11 connected to the actuator 9 via a joint 10 such as a bell crank. ing. As shown in FIG. 2, a total of four blades 11 are provided at 90-degree intervals so as to extend into the jet flow from the nozzle 5, and are individually driven by each joint 10 and actuator 9. It is possible. The propellant grains 3 have a shape in which the burning area increases stepwise, and as shown in the diametrical cross section in FIG. 3, a central hole 12 in which arcs are projected in four directions,
The solid rocket motor 1 has four cavity portions 13 provided at intervals of 90 degrees along an outer side of a concentric circle 17 separated from the central hole 12. An annular insulation 14 that opens the central hole 12 and closes each cavity 13 is provided on the end surface of the propellant grain 3 on the tail side. In addition, the end plate 15 that constitutes the head of the chamber 2
An igniter 16 that is inserted into the central hole 12 is attached to the. The solid rocket motor 1 described above is connected to the head-and-trunk portion 18 shown by the phantom line in FIG. 1 to form a flying body that changes the direction immediately after being vertically launched. Therefore, in the propellant grain 3, the propellant between the central hole 12 and the concentric circle 17 that is in contact with the cavity 13 in the diametrical cross section of the propellant grain 3 is ignited until the initial turning of the projectile is completed. It is set to the amount (or more) to be consumed during the time. Further, as described above, the central hole 12 has less unevenness on the inner surface as compared with the conventional star-shaped inner hole, etc., and the initial combustion area determined by the inner surface is smaller than that of the star-shaped inner hole. Has become quite small. Next, the operation of the solid rocket motor 1 will be described together with the movement of the flying object. As shown in FIG. 4, the projectile R is vertically launched by igniting the propellant grains 3 by the igniter 16 and is indicated by an arrow in the figure by the operation of the jet vane device 7 at the position a immediately after that. The thrust direction control is performed as described above, and the thrust direction is returned to the machine axis direction (position b in FIG. 4) after the turning starts accordingly. At this time, the solid rocket motor 1 generates thrust F ₁ which is about half the maximum thrust as shown in FIG. 5 due to the ignition of the inner surface of the central hole 12. Actually, since the combustion progresses in such a manner that the central hole 12 expands, the thrust gradually increases with the combustion area (F _{1 in} FIG. 5 has an inclined shape that increases with time). The degree is small, and the thrust F ₁ during turning can be regarded as about half of the maximum thrust. Therefore, since the flying vehicle R during turning does not undergo excessive vertical acceleration as compared with the case of using the conventional solid rocket motor in which the thrust rises to a maximum value immediately after ignition, it smoothly turns (first The position is changed to the horizontal state (position e in FIG. 4). Further, in the solid rocket motor 1, when the above turning is completed, the propellant between the central hole 12 and the concentric circle 17 contacting the cavity 13 is burned out,
The combustion area is rapidly increased by the inner surface of the cavity 13 as the cavity 13 is opened, and the thrust F ₂ close to the maximum thrust is obtained.
Generate. As a result, the flying object R is further accelerated and continues to fly horizontally (position f in FIG. 4). Although it depends on the shape of the cavity 13, the thrust force F ₂ is not always constant as shown in FIG. 5, and may be a thrust force that gradually decreases or increases. As described above, since the solid rocket motor 1 has a small initial thrust F ₁ , that is, the thrust until the projectile R finishes turning, the solid rocket motor 1 generates energy to cause the projectile R to make a tail swing motion. Since there is no loss and the thrust F ₁ effectively acts on the turning motion, the turning motion of the flying vehicle R is smooth and quick even though the thrust is small. And
Due to the improvement of the turning performance, the loading height of the flying vehicle R can be lowered as compared with the conventional solid rocket motor. Further, the solid rocket motor 1 has a smaller initial velocity immediately after launch than the conventional solid rocket motor, but achieves smooth acceleration from the inside of the turning due to the good turning described above, and then the combustion area by the cavity 13 Since the thrust is further increased by increasing, the sufficient initial velocity is obtained, and as a result, the flight velocity is improved. Furthermore, for example, since it is possible to save the amount of propellant that was a loss of energy in the conventional solid rocket motor, the flight speed is further improved as the motor weight is reduced. When is constant, the flight distance increases. 6 to 8 are views for explaining another embodiment of the present invention. It should be noted that the same parts as those in the configuration of the previous embodiment are designated by the same reference numerals and the description thereof will be omitted. That is, in the propellant grains 22 of the solid rocket motor 21 in this embodiment, the solid end face combustion part 25 is connected to the tail of the inner surface combustion part 24 having the inner hole 23 as a shape in which the combustion area gradually increases. The inner hole 23 serves as a cavity for increasing the combustion area. The inner hole 23 has four groove portions 23a at 90-degree intervals in a circular central hole portion in a diametrical cross section. In addition, the internal combustion section 24
Has a volume (length in the machine axis direction) that is sufficiently larger than that of the end face combustion section 25. The end surface combustion section 25 is set to have an amount of propellant that can be consumed substantially in the time from ignition to completion of initial turning of the flying object. In the solid rocket motor 21, the igniter 16 is attached to the small diameter portion 4 of the chamber 2 toward the end face combustion portion 25. The solid rocket motor 21 described above, after ignition by the igniter 16, generates a constant thrust smaller than the maximum thrust by the combustion of the end face combustion part 25 for a certain period of time, and after the end face combustion part 25 is burned out, the inner surface combustion part 24 The thrust increases as the combustion area rapidly increases due to the holes 23 and the end faces (see FIG. 5). Further, the solid rocket motor 21 has the same effect as that of the previous embodiment (see FIG. 4) in the flying body that changes the direction immediately after it is vertically launched. The solid rocket motor according to the present invention is not limited in configuration to the above-mentioned embodiments, and the shape of the propellant grains, thrust direction control means, etc. can be changed as appropriate. In the above, the case where the thrust changes in two steps was explained, but it is also possible to make it more times.

【The invention's effect】

As described above, the solid rocket motor according to the present invention is a solid rocket motor used for a projectile that changes direction immediately after it is vertically launched. The energy of the propellant during the initial turning is increased because the cavity is provided to increase the burning area of the propellant after the completion of the initial turning to the area where the maximum thrust can be generated with respect to the burning area of the propellant consumed. It has the excellent effect of being able to prevent the loss of, and along with this, the improvement in performance such as the speed improvement of the flying object and the lowering of the input altitude is realized.

[Brief description of drawings]

1 is a sectional view for explaining a solid rocket motor according to an embodiment of the present invention, FIG. 2 is an end view of the solid rocket motor shown in FIG. 1 on the tail side, and FIG. 3 is A in FIG. -A
FIG. 4 is a cross-sectional view taken along a line, FIG. 4 is an explanatory view showing the trajectory and attitude of the projectile after launching using the solid rocket motor shown in FIG. 1, and FIG. 5 is a graph schematically showing the combustion pattern of propellant grains. FIG. 6 is a sectional view for explaining a solid rocket motor according to another embodiment of the present invention, FIGS. 7 and 8 are sectional views taken along the line BB and CC in FIG. 6, FIG. 9 is an explanatory diagram showing the trajectory and posture of a flying object after launching it using a conventional solid rocket motor. 1,21… Solid rocket motor, 3,22… Propellant grain, 13
… Cavity, 23… Inner hole (cavity), R… Flying body.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 57-24438 (JP, A) JP 47-4204 (JP, B1) JP 50-17605 (JP, B2) JP 41 20487 (JP, Y1)

Claims (1)

[Claims] 1. A solid rocket motor used for a projectile that changes its direction immediately after being vertically launched, with respect to a propellant grain, with respect to the burning area of the propellant consumed from the launch to the completion of the initial turning. A solid rocket motor having a cavity portion for increasing the combustion area of the propellant after completion of the initial turning to an area where maximum thrust can be generated.