JPS6380052A - Movable nozzle drive device for rocket - Google Patents

Abstract

PURPOSE:To make it possible to drive a movable nozzle only in one direction when an input signal is isolated, by controlling the flow rate of a servo-valve so that the drive of an actuator is directed in a predetermined direction in such a condition that the value of input current is zero. CONSTITUTION:During flying of a rocket R, when wire breakage or a trouble in a servo-amplifier 25 causes an input signal fed to a servo-valve 20 to drop to zero, no bias current is applied. With this arrangement, even if a piston 21 in an actuator A is operated toward the extension side L, a flapper 37 blocks a contracting side nozzle 36 so that a contracting side port 41 is opened under the action of the servo-valve 20. Accordingly, the supply of fuel from a contracting side load port Q1 is continued at a constant flow rate so that the piston 21 is moved to the contracting side A, and therefore, the direction of a nozzle N is fixed to allow the rocket to dive. With this arrangement, even if the attitude control of the rocket becomes impossible, it is possible to allow the rocket R to fly in a set safe direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a movable nozzle drive device used to drive a movable nozzle of a rocket. (
Conventional Technique #I) The movable nozzle is made by attaching a gimbal ring or rubber to the rocket body, as described on page 652 of the ``Aerospace Engineering Handbook, Expanded Edition'' published by Marubai in April 1981. The nozzle is provided so as to be able to swing through a seal layer consisting of a metal shim and a rocket body, and the rocket body and the nozzle are connected by an appropriate number of actuators, and the direction of the nozzle is adjusted by driving the actuators to expand and contract. I'm trying to change the. Here, the actuator constitutes a part of a servo mechanism that is operated by a reference input signal whose output source is a rate gyro or the like provided in the rocket body. Note that the rate gyro detects the angular velocity around an axis perpendicular to the rocket's axis.

In other words, the movable nozzle driving device drives the servo valve in the selected direction according to the control operation signal obtained by comparing the reference input signal and the feedback signal, and also drives the actuator using the hydraulic pressure from the servo valve. The actuator is driven in the extension or contraction direction, and the displacement of the actuator is converted into an electrical signal by a potentiometer and fed back to the input side. Therefore, when deflection occurs due to external factors such as air currents during flight, the servo mechanism drives the actuator to move the nozzle in a direction that corrects the deflection of the rocket and controls the rocket to always maintain the set attitude. I do. Such attitude control is widely known in the aerospace field.

(Problem to be Solved by the Invention) However, in the movable nozzle drive device as described above, if the input signal to the servo valve is cut off due to a disconnection or equipment failure, for example, the servo valve If the actuator is in a neutral state, keep the nozzle pointing toward the machine axis, and if the actuator is being driven in either direction, continue supplying hydraulic fluid in that direction to fully rotate the nozzle. Since the rocket is tilted, there is a problem in that it is impossible to predict in which direction the rocket will fly. Note that the attitude control described above is performed frequently during flight, so in the event of a failure, there is a high possibility that the nozzle will change to a tilted state, and in this case, the direction of flight of the rocket will become larger. It is extremely dangerous because it changes.

(Object of the Invention) This invention was made by focusing on such conventional problems, and it is possible to drive the movable nozzle in only one direction when the input signal is cut off, and it is possible to drive the movable nozzle in only one direction. The purpose of the present invention is to provide a movable nozzle drive device for a rocket that can direct the rocket to

[Structure of the Invention] (Means for Solving the Problems) A movable nozzle drive device for a rocket according to the present invention includes a servo valve that converts an input electric signal into a fluid flow rate control signal, and a fluid control system of the servo valve. In a rocket movable nozzle drive device that includes an actuator to be driven and a displacement detection unit that sends the amount of displacement of the actuator to the input side as a feedback signal, the actuator is driven in a predetermined direction when the input current value is zero. The servo valve is characterized in that the flow rate of the servo valve is controlled so as to direct the flow rate to the servo valve.

(Example) The present invention will be explained below based on the drawings.

FIG. 1 to FIG. 6 are diagrams explaining one embodiment of the present invention.

FIG. 1 is a diagram illustrating a movable nozzle, in which reference numeral R represents a rocket body having a combustion chamber 1, and reference numeral N represents a nozzle. The nozzle N is mounted so as to be swingable by connecting a holder ring 2 fixed to the outer peripheral side of the throat part T and a nozzle holder 3 fixed to the tail part of the rocket body R with a flexible joint 4. . The flexible joint 4 is made by alternately laminating heat-resistant rubber and metal shims that form a concentric spherical shape around a pivot point (not shown) set on the axis of the rocket, and is located on the side of the combustion chamber 1. The surface is a flexible thermal protection boot 5
and covered with a heat insulating material 6. Furthermore, a radiation shield 7 is provided inside the combustion chamber 1 and protrudes to cover the connecting portion by the flexible joint 4.

A bracket 8 provided near the tail of the rocket body R and a bracket 9 provided on the outer surface of the nozzle cone are connected by an actuator A.
As shown in FIG. 2, they are provided at two locations 90 degrees apart on the circumference. A reference rod 10 is provided at a position 180° different from the center position on the circumference of both actuators A, and a battery 11. Hydraulic pump 12 with built-in motor
．． Motor switch box 13. Accumulator 14
, a reservoir 15, etc. are provided.

The drive device for the movable nozzle constitutes a servo mechanism, and as shown in FIG. The actuator A is reciprocally driven by the flow rate control of the servo valve 20, and a potentiometer 22 is a displacement detecting section that sends the amount of displacement of a piston built in the actuator A as a feedback signal to the input side. Further, reference numeral C in FIG. 3 is a controller for obtaining a control operation signal, and this controller C is connected to the function generator 23. A system in which a comparator 24 and a servo amplifier 25 are sequentially connected is provided corresponding to each actuator A, and the feedback signal from the potentiometer 22 is input to the comparator 24. Note that the reference rod 10 is electrically connected to a feedback amplifier 26 in the controller C, and this feedback amplifier 26 is connected to each comparator 24. Here, the reference input signal input to the controller C is a signal whose output source is a detection device such as an accelerometer or a rate gyro provided on the rocket body H. Therefore, two detection devices are provided so as to be able to detect accelerations or angular velocities about two axes that are orthogonal to the axis of the rocket and mutually orthogonal, and drive each servo valve 20 with the respective detection signals.

Furthermore, to explain the above drive device in detail based on FIG. 4, the servo valve 20 includes a torque motor 30 operated by input current, and a spool 32 that slides inside a sleeve 31. It communicates with the cylinder 27 housing the piston 21 of A via the contraction side load boat Q+ and the expansion side load boat Q2. The torque motor 30 includes an armature 34 provided at the center of a coil 33, and a flapper 37 extending between an extension nozzle 35 and a contraction nozzle 36 facing each other at an appropriate interval. 37 is held by a flexure tube 38 having sufficient flexibility. Both nozzles 35 and 36 are connected to the pressurized boat Pl.
, located at the end of the flow path 39.40 led from P2,
Each channel 39,40 communicates with both ends of the sleeve 31, respectively. The sleeve 31 also includes the spool 3.
A contraction-side supply boat 41 and an extension-side supply boat 42, a contraction-side return boat 43, and an extension-side return boat 44, which are opened and closed relative to each other by the movement of the contraction-side supply boat 41 and extension-side return boat 44, are in communication. In addition, each nozzle 35.
44, and a feedback spring 45 is provided between the flapper 37 and the spool 32.

The servo valve 20 is controlled to direct the piston 21 of the actuator A in only one direction when the input current is cut off. In other words, as shown by the broken line in Figure 5, a typical servo valve attempts to reduce the flow rate of hydraulic oil to zero when the input current becomes zero.
On the other hand, the servo valve 20 is connected to the torque motor 3
Shims 47 and 48 having different thicknesses are interposed between both ends of the 0 and the body 46 forming the sleeve 31 etc., the torque motor 30 is tilted, and the flapper 37 closes the contraction side nozzle 3.
6 is closed. Therefore, if the same pressure is applied from each pressurized boat P+ + P2 in this state, the hydraulic oil flowing to the extension side nozzle 35 returns through the nozzle 35 and flows out to the boats 43 and 44, but the hydraulic oil flows to the contraction side nozzle 3.
Hydraulic oil to the spool 32 is increased in pressure in the pipe 40.
(push to the left in FIG. 4) to open the contraction side supply boat 41 and the extension side return boat 44,
The contraction side return boat 43 and the expansion side supply port 42 are closed. As a result, hydraulic oil is supplied from the contraction side supply boat 41 into the cylinder 27 through the sleeve 31 and the contraction side load boat Ql, and pushes the piston 21 to the contraction side S. In other words, as shown by the solid line in FIG. 5, the servo valve 20 continues to supply a constant flow IF to the contraction side S when the input current becomes zero.
When actually operating, bias current B is applied to position the flapper 37 at the center of both nozzles 35, 36, open both nozzles 35, 36, and keep the spool 32 in the neutral position.

Next, the operation of the movable nozzle driving device will be explained.

First, the rocket (main body) R normally flies with the actuator A facing downward, as shown in Figure 6(a).
At this time, the attitude around the machine axis is controlled by a roll axis control device using a small rocket motor or the like. When a deflection around an axis perpendicular to the machine axis occurs, the displacement (for example, angular velocity) is detected by a rate gyro or the like and is input to the controller C. In the controller C, a function generator 23 converts the detection signal into a reference input signal, a comparator 24 compares the reference input signal and a feedback signal, and a control operation signal obtained is amplified into a constant current by a servo amplifier 25. Input to servo valve 20. Further, in the servo valve 20, the flapper 37 is moved in a predetermined direction in accordance with the control operation signal, and the corresponding nozzle 35, 36 is closed, and the spool 32 is closed.
By pushing and driving the piston 21 toward the contraction side S or the expansion side with hydraulic oil supplied into the cylinder 27 of the actuator A, the nozzle N is operated in a direction to correct the deflection of the rocket R. The aforementioned bias current B is always applied to the servo valve 20, and the displacement of the piston 21 is converted into an electric signal by the potentiometer 22 and sent to the comparator 24 as a feedback signal.
is being sent to. Note that the nozzle N is pushed backward by the pressure inside the rocket as the flexible joint 4 expands, and as a result it tries to rotate around each actuator A as a fulcrum, but this displacement is caused by the reference rod 1.
0 and is input to each comparator 24 via the feedback amplifier 26, thereby controlling each actuator A to extend.

Next, if the input signal (current) to the servo valve 20 becomes zero due to a wire breakage or failure of the servo amplifier 25 while the rocket) H is in flight, the bias current B will naturally not be loaded, so if the piston 21 is operating toward the expansion side, the flapper 37 closes the contraction side nozzle 36, and the contraction side supply boat 41 is opened by the action of the servo valve 20 described above. Therefore, by continuing to supply a constant flow rate F from the contraction side load (b) Ql, the piston 21 moves to the contraction side S, and as shown in FIG.
) As shown in ), fix the direction of the nozzle N and launch the rocket) R.
fly downwards (in the direction of the arrow in the figure). In other words, if the launch site is located on the coast, as is often the case,
In the event of a failure as described above, the rocket can be dropped onto the ocean, avoiding danger to the ground.

Note that the detailed structure of the movable nozzle driving device is not limited to the above embodiment, and for example, as shown in FIG. 50, a servo valve 5 for directing the actuator in a predetermined direction is used.
0 flow rate control, the spool 51 is shifted from the neutral position by varying the lengths of the re-balancing springs 52, 53 or by varying the strength of the repulsive force of the re-balancing springs 52, 53. When operating the spool 51, it is preferable to maintain the spool 51 in the neutral position by applying a bias current as in the above embodiment.
In addition to mechanical flow control as described above, it is also possible to apply electrical bias to the servo valve using a system separate from the servo amplifier 25. Furthermore, the direction in which the actuator is operated differs depending on the position of the actuator in the rocket and the direction in which it is intended to fly in the event of a failure. For example, when using two actuators A as in the above embodiment, both In addition to providing the servo valve 20 with a configuration that controls the flow rate in the same direction, it is also possible to control the flow rate in different directions.

[Effect of the Invention 1] As explained above, the movable nozzle drive device for a rocket of the present invention includes a servo valve that converts an input electric signal into a fluid flow rate control signal, and a servo valve that is driven by fluid control of the servo valve. A movable nozzle drive device for a rocket, comprising: an actuator for moving the actuator; and a displacement detecting section that sends the amount of displacement of the actuator to an input side as a feedback signal.

In this case, since the flow rate of the servo valve is controlled in order to direct the drive of the actuator in a predetermined direction when the input current value is zero, the input signal to the servo valve is cut off and attitude control becomes impossible. In this case, the movable nozzle can be forcibly driven in only one direction, which has the great effect of making the rocket fly in the set safe direction.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the nozzle part of a rocket equipped with a movable nozzle drive device according to an embodiment of the present invention, FIG. 2 is an explanatory view of the nozzle shown in FIG. 1, viewed from the tail direction, and FIG. A block diagram explaining the servo mechanism, Figure 4 is an explanatory diagram schematically showing the drive device, Figure 5 is a graph explaining the flow characteristics of the servo valve, and Figures 6 (a) and (b) are rockets in flight. FIG. 7 is an explanatory view showing another servo valve to which the present invention is applicable. R...Rocket body, A...Actuator, N...Nozzle. 20.50... Servo valve, 22... Potentiometer (displacement detection section).

Claims (1)

[Claims] (1) A servo valve that converts an input electrical signal into a fluid flow rate control signal, an actuator driven by fluid control of the servo valve, and a displacement detector that sends the amount of displacement of the actuator to the input side as a feedback signal. In a rocket movable nozzle drive device equipped with
A movable nozzle drive device for a rocket, characterized in that the flow rate of the servo valve is controlled to direct the drive of the actuator in a predetermined direction when the input current value is zero.