JPH11173213A - Mounting structure of exhaust noise silencer for aircraft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exclude the suppressing action by an exhaust noise silencer when the increase of the engine performance is needed and to obtain the desired exhaust noise reduction efficiency in the ordinary flight by providing a mounting/demounting mechanism for mounting or demounting the exhaust noise silencer to or from an aircraft, and enabling the demounting operation by the remote control. SOLUTION: When the reduction of the exhaust noise is needed in the take- off, a piston rod 12a of an actuator 12 is drawn, so that a lever 8 is rotated anticlockwise on a pin 9, and an engagement part 8a of the lever 8 is engaged with an engagement part 7a of a hook 7. Whereby an exhaust noise reduction duct 3 is supported by the engine 2 through a mounting/demounting mechanism 6. The exhaust noise of the engine is reduced in the exhaust mixer of an exhaust noise reduction duct 3. During the flight, the piston rod 12a of the actuator 12 is extended, the lever 8 is rotated clockwise, and the engagement part 8a of the lever 8 is disengaged with the engagement part 7a of the hook 7. The exhaust noise reduction duct 3 can be easily demounted from the engine 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust noise reduction device mounting structure for reducing the exhaust noise of an engine in an aircraft.

[0002]

2. Description of the Related Art FIGS. 8 to 10 show an outline of an exhaust system of an aircraft jet engine (hereinafter referred to as an engine). FIG. 8 is a sectional view of an upper half along an engine axis 2a.
FIG. 9 is a plan view of the exhaust duct portion, and FIG. 10 is a plan view (cross-sectional view) of the exhaust noise reduction device mounting portion. 8 to 10, 2 is an engine, 1 is a nozzle cone of the engine 2,
20 is a fan duct through which fan air 28 flows,
Reference numeral 23 denotes an exhaust duct through which the engine exhaust gas 5 flows through the internal exhaust passage 23a.

An exhaust mixer 27 includes a fan air 28 passing through the fan duct 20.
Is mixed with the engine exhaust 5 to convert low-frequency sound from the engine exhaust 5 into high-frequency sound to reduce noise. Then, the mixed gas of the engine exhaust 5 and the fan air 28 is ejected to the rear of the aircraft from an exhaust passage 23 a between the exhaust duct 23 and the nozzle cone 1.

As shown in FIG. 10, an exhaust sound reducing duct 3 for reducing the exhaust sound of the engine 2 in such an aircraft is configured by fixing a sound absorbing liner 25 in an exhaust duct 23. The noise generated by the engine exhaust 5 is absorbed and attenuated.

[0005]

In the conventional aircraft shown in FIGS. 8 to 10, the exhaust sound reducing duct 3 for reducing the noise caused by the engine exhaust 5 has a sound absorbing function in the exhaust duct 23. The sound absorbing liner 25 is connected to the exhaust duct 23
It is constituted by fixing to. However, in aircraft equipped with such an exhaust noise reduction device, when performance increases before takeoff or during flight are required, the exhaust noise reduction device suppresses engine performance increase. Required.

However, in the prior art shown in FIGS. 8 to 10, since the exhaust noise reduction duct 3 is fixed to the engine 2, that is, to the exhaust duct 23, it is removed when the above-described performance increase is required. And the required increase in engine performance cannot be obtained.

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, the present invention eliminates the suppression effect of the exhaust noise reduction device when the engine performance needs to be increased, and can obtain the required exhaust noise reduction effect during normal flight. It is an object of the present invention to provide a mounting structure of an exhaust noise reduction device for a vehicle.

[0008]

According to a first aspect of the present invention, there is provided an aircraft having an exhaust noise reduction device at a rear portion of an engine for reducing the exhaust noise of the engine. The present invention proposes an installation structure of an aircraft exhaust noise reduction device, comprising an attachment / detachment mechanism for attaching / detaching the reduction device to / from an aircraft, and an attachment / detachment mechanism enabling detachment of the exhaust noise reduction device by remote control.

According to the first aspect of the present invention, when the exhaust sound is required to be reduced, such as when the aircraft takes off, the exhaust noise reducing device is connected to the engine of the aircraft by the attachment / detachment mechanism, so that the exhaust noise is reduced. Can be done.

[0010] During an operation that requires an increase in engine performance rather than a reduction in exhaust noise, such as before takeoff of the aircraft or during normal flight, the attachment / detachment mechanism is removed to separate the exhaust noise reduction device from the engine of the aircraft. And the weight is reduced, and high-performance operation can be performed. In particular, since the exhaust sound reduction device is a detachable mechanism that enables remote detachment of the exhaust sound reduction device, the device can be easily separated by operating the driver's seat even during normal flight.

The second to fourth inventions embody the first invention. The second invention is characterized in that the attachment / detachment mechanism includes a first engagement member provided on the exhaust noise reduction device side. A second engaging member provided on the aircraft side, and an actuator for receiving and operating a remote operation signal to disengage the first engaging member and the second engaging member. .

According to a third aspect of the present invention, the attachment / detachment mechanism has a joint mechanism in which an explosive exploding by a remote operation signal is provided inside, and the explosion explosion causes the exhaust noise reduction device to be detached from the aircraft. Become.

[0013] Further, a fourth invention is directed to an electromagnet in which the attaching / detaching mechanism is turned on / off by a remote operation signal to generate a magnetic field opposite to the permanent magnet provided on the exhaust noise reduction device side. And

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only.

1 to 3 show a first embodiment of the present invention. FIG. 1 is a sectional view of an engine and an exhaust noise reduction device taken along an axis of the engine. FIG. 2 is a view showing FIG. 1 and FIGS. 6
3 is an enlarged view of a portion Z in FIG.

1 to 3, reference numeral 2 denotes an engine, and reference numeral 26 denotes an exhaust nozzle for guiding the engine exhaust 5. 3 is an exhaust noise reduction duct. As shown in FIG. 2, the exhaust noise reduction duct 3 includes an annular sound absorbing liner 25 and an exhaust mixer 27 provided between an inner periphery of the liner 25 and an outer periphery of the exhaust nozzle 26. The annular sound absorbing liner 25 has the same sound absorbing function as the related art shown in FIG. The exhaust mixer 27 is, as shown in FIG.
It is attached to the outer periphery of the exhaust nozzle 26 and is formed in a wavy shape along the circumferential direction to mix the engine exhaust 5 and the externally introduced air 4.

Reference numeral 6 denotes an attachment / detachment mechanism for attaching / detaching the exhaust noise reduction duct 3 to / from the engine 2. That is, the attachment / detachment mechanism 6 is configured as shown in FIG. 3. In FIG. 3, reference numeral 7 denotes a hook fixed to the inner peripheral side of the sound absorbing liner 25 of the exhaust sound reduction duct 3; Is a lever which is pivotally supported by the bracket 10 via a pin 9 at the center thereof, and 12 is an actuator.

An engaging portion 8 a is provided at one end of the lever 8, and can be disengaged by an operating force of the actuator 12 and an engaging portion 7 a provided at the tip of the hook 7. The other end of the lever 8 has the actuator 1
The two piston rods 12a are connected via pins 11, and the lever 8 can be turned around the pins 9 by the operation of the actuator 12, as shown by the arrow in FIG. 3S.

When it is necessary to reduce the exhaust noise at the time of takeoff or the like in an aircraft equipped with the detachable mechanism 6, when the piston rod 12a of the actuator 12 is retracted, the lever 8 rotates counterclockwise about the pin 9 as a fulcrum. Then, the engaging portion 8a of the lever 8 is engaged with the engaging portion 7a of the hook 7. As a result, the exhaust noise reduction duct 3 is
Is supported by the engine 2.

In such a supporting state, the engine exhaust 5 is mixed with the externally introduced air 4 in the exhaust mixer 27 of the exhaust noise reducing duct 3 to convert low-frequency sound generated by the engine exhaust 5 into high-frequency sound to reduce noise. The generated noise is absorbed and attenuated by the sound absorbing liner 25.

When it is necessary to increase the engine performance during a flight or the like, the piston rod 12a of the actuator 12 is extended, and the lever 8 is rotated clockwise as indicated by an arrow S in FIG. Is disengaged from the engaging portion 8a of the hook 7 and the engaging portion 7a of the hook 7. As a result, the exhaust noise reduction duct 3 can be easily removed from the engine 2, and the loss due to exhaust of the engine 2 can be reduced, and high-performance operation with reduced weight can be performed.

4 and 5 show a second embodiment of the present invention. FIG. 4 is a sectional view corresponding to FIG. 1, and FIG. 5 is an enlarged view of a portion Y in FIG. In this embodiment, an explosive-type attaching / detaching mechanism using explosives is used for the attaching / detaching mechanism of the exhaust noise reduction duct.

That is, in FIGS. 4 and 5, the attachment / detachment mechanism 6 of the exhaust noise reduction duct 3 includes a joint 24 in which the explosive 15 is incorporated. And the exhaust noise reduction duct 3 is
The sound absorbing liner 25 is supported by an exhaust nozzle 26 of the engine 2 via a joint 24 in which the explosive 15 is incorporated. Reference numeral 14 denotes an electric wiring connected to the explosive 15.

In the second embodiment, during operation requiring reduction of exhaust noise, the power supply to the electric wiring 14 is cut off, and the exhaust noise reduction duct 3 is connected to the joint 24.
Through the engine 2. Thus, the same exhaust mixer 27 and sound absorbing liner 25 as in the first embodiment are provided.
The exhaust sound is attenuated.

On the other hand, in an operating state in which an increase in engine performance is prioritized over a reduction in exhaust noise, when electricity is supplied to the electric wiring 14, the explosive 15 explodes, and the exhaust noise reduction duct 3 is connected to the engine 2 at the joint 24. Be separated. As a result, the exhaust noise reduction effect of the exhaust noise reduction duct 3 is cut, and the engine performance is improved.

FIGS. 6 and 7 show a third embodiment of the present invention. FIG. 6 is a sectional view corresponding to FIG. 1, and FIG. 7 is an enlarged view of a portion X in FIG. In this embodiment, a magnet-type attachment / detachment mechanism combining an electromagnet and a permanent magnet is used for the attachment / detachment mechanism of the exhaust noise reduction duct.

That is, in FIGS. 6 and 7, reference numeral 3 denotes the first,
This is an exhaust noise reduction duct having the same configuration as that of the second embodiment, and the reduction duct 3 is attached to the engine 2 by a detachable mechanism 6 including two permanent magnets 19 and 19 and an electromagnet 18 interposed therebetween. Supported. One of the permanent magnets 19 is fixed to an exhaust nozzle 26 of the engine 2,
The other of the permanent magnets 19 is fixed to the exhaust noise reduction duct 3,
An electromagnet 18 is interposed between the two permanent magnets 19,19.

The electromagnet 18 is connected to a power supply (not shown) with a control device via an electric wiring 17 so as to be energized or cut off by the power supply.

In the third embodiment, the power supply to the electromagnet 18 is interrupted during the operation in which the exhaust noise needs to be reduced.
Thereby, the two permanent magnets 19, 19 are fixed (bonded) via the electromagnet 18, and the exhaust noise reduction duct 3 is supported by the engine 2 via the permanent magnets 19, 19 and the electromagnet 18, thereby reducing the exhaust noise. Works. On the other hand, in an operation state in which an increase in engine performance is prioritized over a reduction in exhaust sound, when power is supplied to the electromagnet 18 via the electric wiring 17 from the power supply, a magnetic field opposite to the permanent magnets 19 and 19 is generated in the electromagnet 18, The two permanent magnets 19, 19 are separated at the electromagnet 18.

As a result, the exhaust noise reduction duct 3 is separated from the engine 2 and the exhaust noise damping action is cut off.
An increase in engine performance is obtained. In the second and third embodiments, the same members as those in the first embodiment are denoted by the same reference numerals.

[0031]

As described above, according to the present invention, the exhaust noise reduction device is connected to the engine of the aircraft by an attachment / detachment mechanism during an operation that requires reduction of the exhaust noise, such as at the time of takeoff of the aircraft. Reduced driving can be achieved, and when driving that requires an increase in engine performance rather than reduction of exhaust noise, such as before takeoff of an aircraft or during normal flight, it can be attached and detached by remote control from the driver's seat etc. By removing the mechanism and separating the exhaust noise reduction device from the engine of the aircraft, the loss due to exhaust is reduced, the weight is reduced, and high-performance operation can be performed.

Therefore, according to the present invention, by connecting / disconnecting the exhaust sound reducing device to / from the engine of the aircraft by the attaching / detaching device, the operating state in which the exhaust noise is reduced and the exhaust noise reduction are accompanied. It is possible to easily use the operating state in which the weight is reduced and the engine performance is increased without loss, thereby enabling efficient aircraft operation.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view along an engine axis of an aircraft engine and an exhaust noise reduction device according to a first embodiment of the present invention.

FIG. 2 is a view taken in the direction of arrow A in FIGS. 1, 4, and 6;

FIG. 3 is an enlarged view of a portion Z in FIG. 1;

FIG. 4 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 5 is an enlarged view of a portion Y in FIG. 4;

FIG. 6 is a view corresponding to FIG. 1, showing a third embodiment of the present invention.

FIG. 7 is an enlarged view of a part X in FIG. 6;

FIG. 8 is a cross-sectional view of a main part of an upper half of an aircraft engine according to the related art, taken along an axis.

FIG. 9 is a plan view of an exhaust duct according to the related art.

FIG. 10 is a cross-sectional view of a main part of the exhaust noise reduction device according to the related art, taken along an engine axis.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle cone 2 Engine 3 Exhaust sound reduction duct 4 External introduction air 5 Engine exhaust 6 Detachment mechanism 7 Hook 8 Lever 12 Actuator 15 Explosives 18 Electromagnet 19 Permanent magnet 24 Joint 25 Sound absorption liner 26 Exhaust nozzle 27 Exhaust mixer

Claims (4)

[Claims] An aircraft provided with an exhaust noise reduction device at a rear portion of an engine for reducing exhaust noise of the engine, comprising: a detachable mechanism for attaching and detaching the exhaust noise reduction device to and from the aircraft; An installation structure for an aircraft exhaust noise reduction device, which is a detachable mechanism that enables detachment by remote control. 2. The detachable mechanism receives a first engagement member provided on the exhaust noise reduction device side, a second engagement member provided on the aircraft side, and a remote operation signal. 2. The mounting structure for an exhaust noise reduction device for an aircraft according to claim 1, further comprising an actuator for engaging and disengaging the first engagement member and the second engagement member. 3. An explosive that explodes in response to an operation signal from a remote place is provided inside the detachable mechanism, and has a joint mechanism that detaches the exhaust noise reduction device from the aircraft side due to the explosion of the explosive. 2. The mounting structure of the aircraft exhaust noise reduction device according to 1. 4. The apparatus according to claim 1, wherein the attachment / detachment mechanism includes a permanent magnet provided on the exhaust noise reduction device and an operation signal from a remote location.
2. The mounting structure for an exhaust noise reduction device for an aircraft according to claim 1, further comprising: an electromagnet configured to generate an opposite magnetic field to the permanent magnet by N / OFF.