APU air inlet air door system

Abstract

The invention discloses an APU air inlet air door system. The length of an air inlet air door can be increased on the basis that an opening of an aircraft skin is not changed. The APU air inlet air door system comprises an air channel, an air inlet and an air outlet, the air inlet air door is used for opening or closing the air channel; the air inlet air door comprises an air door fixed section and an air door moving section capable of stretching out and drawing back relative to the air door fixed section, and when the air inlet air door is closed, the air door moving section can stretch out and draw back relative to the air door fixed section. When the air inlet air door is opened, the actuator enables the air door moving section to retract relative to the air door fixed section so as to shorten the overall length of the air inlet air door, and when the air inlet air door is opened, the actuator enables the air door moving section to extend relative to the air door fixed section so as to increase the overall length of the air inlet air door.

Description

Technical Field

[0001] The invention relates to an air intake damper system of an auxiliary power unit (APU) of an aircraft, namely, an APU air intake damper system. Background Art

[0002] The function of the APU air intake system is to provide the air flow required by the APU under various working conditions, and to reduce the pressure loss and intake distortion at the APU inlet, so as to ensure the normal operation of the APU system. The APU air intake damper system is an important component of the APU air intake system. The air intake damper is generally set at the opening on the aircraft skin. When the auxiliary power unit is working, the air intake damper is opened by the actuation system. The size of the air intake damper is generally consistent with the opening size of the aircraft skin to reduce the aerodynamic resistance of the aircraft. The opening size of the aircraft skin is usually determined by the air inlet duct. Therefore, the size of the APU air intake damper will be limited by the cross-sectional size of the air inlet duct.

[0003] The damper actuator is the actuating component that opens / closes the APU intake damper. Usually, the actuator and damper form a swing guide rod mechanism, as shown in Figure 1(a). During the damper opening process, the actuator not only extends the pull rod, but also needs to rotate. The actuator usually needs to pass through the air intake duct to act on the damper. However, the air intake system is part of the circumferential firewall of the APU cabin, and the actuator often needs to be fireproof sealed at the cabin penetration. In Figure 1(a), A represents the damper, B represents the actuator pull rod, and C represents the actuator.

[0004] Since the actuator itself needs to rotate, it is necessary to add a fireproof cover on the outside of the actuator, and add flexible seals and other parts at the tie rod through the cabin to meet the fire protection requirements of the APU cabin, as shown in Figure 1(b). In Figure 1(b), D represents the APU air intake door, E represents the aircraft skin, F represents the air intake duct, G represents the actuator, and H represents the actuator fireproof cover.

[0005] The existing APU damper actuation system has the following two main problems:

[0006] (1) During the flight of the aircraft, due to the existence of the boundary layer, the air velocity near the aircraft fuselage is low. At the same time, the length of the APU air intake damper is limited by the size of the air intake duct. The APU air intake damper cannot effectively capture the mainstream airflow, resulting in a decrease in the actual APU intake total pressure recovery coefficient, which in turn affects the APU high-altitude starting performance;

[0007] (2) Because the actuator itself needs to rotate, in order to meet the fire protection requirements, it is necessary to add additional flexible fire protection components such as metal fire protection covers and rubber sealing sleeves to achieve the fire protection function. The fire sealing structure of the actuator through the cabin is relatively complex, with high cost and difficult installation. Summary of the invention

[0008] In view of the above problems, an object of the present invention is to provide an APU air intake damper system, which can increase the length of the air intake damper without changing the opening of the aircraft skin.

[0009] Another object of the present invention is to provide an APU air intake damper system that can meet the actuator's cabin penetration fire protection requirements in a simple form.

[0010] In order to achieve the above-mentioned purpose of the present invention, the present invention provides an APU air intake damper system, comprising: an air duct; an air intake damper that opens or closes the air duct; and an actuator that opens or closes the air intake damper, wherein the air intake damper comprises a damper fixed section and a damper movable section that can be extended and retracted relative to the damper fixed section, when the air intake damper is closed, the actuator retracts the damper movable section relative to the damper fixed section to shorten the overall length of the air intake damper, and when the air intake damper is opened, the actuator extends the damper movable section relative to the damper fixed section to increase the overall length of the air intake damper.

[0011] According to the APU air intake damper system of the present invention, since the air intake damper includes a damper fixed section and a damper movable section that can be extended and retracted relative to the damper fixed section, the length of the air intake damper can be increased without changing the opening of the aircraft skin, which is beneficial for the air intake damper to capture the incoming flow, improve the APU air intake / ventilation total pressure recovery coefficient, and improve the APU air starting performance.

[0012] Preferably, the damper movable section achieves extension and retraction relative to the damper fixed section by sliding relative to the damper fixed section.

[0013] According to the APU air intake damper system of the present invention, the expansion and contraction of the damper moving section relative to the damper fixed section can be achieved through a simple sliding structure.

[0014] Preferably, a slide rail is provided on the damper fixed section, and a slider capable of sliding on the slide rail is provided on the damper movable section.

[0015] According to the APU air intake damper system of the present invention, the expansion and contraction of the damper moving section relative to the damper fixed section can be achieved through a simple matching structure of a slide rail and a slider.

[0016] Preferably, limiting members are provided at both ends of the slide rail, and the limiting members are used to limit the telescopic range of the damper moving section.

[0017] According to the APU air intake damper system of the present invention, the telescopic range of the damper movable section relative to the damper fixed section can be limited, thereby preventing the damper movable section from escaping from the damper fixed section.

[0018] Preferably, the actuator has an actuating rod, the actuating rod is connected to the damper moving section via a ball hinge, and the damper moving section is extended and retracted as the actuating rod is extended and retracted.

[0019] According to the APU air intake damper system of the present invention, the rotation of the actuator itself is replaced by the movement between the damper fixed section and the damper movable section. Therefore, the actuator only needs to perform linear motion during the actuation process without rotation. The actuator's cabin penetration fire protection requirements can be met in a simple form without the need to set up flexible components such as fireproof covers or rubber seals.

[0020] Preferably, an actuator fixing boss for fixing the actuator is provided in the air inlet passage, and a flange on the housing of the actuator is connected to the actuator fixing boss via a fastener.

[0021] The APU air intake damper system according to the present invention can meet the cabin penetration fire protection requirements of the actuator through a simple metal connection structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1( a ) is a schematic diagram schematically showing the operating principle of a conventional APU intake damper system.

[0023] FIG. 1( b ) is a schematic diagram schematically showing the structure of a conventional APU intake damper system.

[0024] Figure 2 It is a front view schematically showing the structure of the APU intake damper system according to the embodiment of the present invention.

[0025] Figure 3 It is a side view schematically showing the structure of the APU intake damper system according to the embodiment of the present invention.

[0026] Figure 4 The diagram schematically shows the connection structure of the damper moving section, the damper fixed section and the actuator in the APU air intake damper system according to the embodiment of the present invention.

[0027] Figure 5 yes Figure 4 AA line section view.

[0028] (Explanation of symbols)

[0029] 100 APU air intake damper system

[0030] 10 Inlet damper

[0031] 11 Opening

[0032] 1 Airway

[0033] 2 Actuators

[0034] 3 Actuator fixing boss

[0035] 4 Damper moving section

[0036] 5. Air door fixed section

[0037] 6 Aircraft skin

[0038] 7 Sliders

[0039] 8 Slide rails

[0040] 9 Actuator rod DETAILED DESCRIPTION

[0041] Various embodiments of the present invention will now be described in detail, examples of which are shown in the accompanying drawings and are described below. Although the present invention will be described in conjunction with the exemplary embodiments, it should be appreciated that this specification is not intended to limit the present invention to those exemplary embodiments. On the contrary, the present invention is intended to cover not only these exemplary embodiments, but also various alternative forms, modifications, equivalent forms and other embodiments that may be included within the spirit and scope of the present invention as defined by the appended claims.

[0042] Next, combine Figures 2 to 5 An APU air intake damper system 100 according to an embodiment of the present invention will be described.

[0043] Figure 2 1 is a front view schematically showing the structure of the APU intake damper system 100 according to the embodiment of the present invention. Figure 3 1 is a side view schematically showing the structure of the APU intake damper system 100 according to the embodiment of the present invention. Figure 4 Schematic diagram schematically showing the connection structure of the damper moving section 4, the damper fixed section 5 and the actuator 2 in the APU intake damper system 100 according to the embodiment of the present invention. Figure 5 yes Figure 4 AA line section view.

[0044] The APU air intake damper system 100 of the present invention is used for an auxiliary power unit air intake system of an aircraft, such as Figure 2 - Figure 3 As shown, it includes: an air passage 1; an air intake damper 10 for opening or closing the air passage 1; and an actuator 2 for opening or closing the air intake damper 10.

[0045] The air duct 1 is arranged inside the aircraft skin 6 and is used to introduce the external air of the aircraft into the APU. An actuator fixing boss 3 for fixing the actuator 2 is arranged on the air inlet 1.

[0046] An opening 11 is provided on the aircraft skin 6 at a position corresponding to the air duct 1, and an air intake damper 10 is used to open or close the opening 11, thereby opening or closing the air duct 1. Normally, when the APU (auxiliary power unit) is working, the air intake damper 10 is opened, otherwise, the air intake damper 10 is in a closed state.

[0047] The air intake damper 10 includes a damper fixed section 5 connected to the aircraft by a latch, for example, and a damper movable section 4 that can be extended and retracted relative to the damper fixed section 5. When the air intake damper 10 is closed, the actuator 2 retracts the damper movable section 4 relative to the damper fixed section 5 to shorten the overall length of the air intake damper 10. When the air intake damper 10 is opened, the actuator 2 extends the damper movable section 4 relative to the damper fixed section 5 to increase the overall length of the air intake damper 10.

[0048] In this embodiment, the damper moving section 4 is extended and retracted relative to the damper fixed section 5 by sliding relative to the damper fixed section 5. Of course, the present invention is not limited thereto, as long as the damper moving section 4 can be extended and retracted relative to the damper fixed section 5.

[0049] Specifically, in this embodiment, if Figure 4 - Figure 5 As shown, slide rails 8 are respectively arranged on both sides of the damper fixed section 5, and sliders 7 that can slide on the slide rails 8 are respectively arranged on both sides of the damper movable section 4. By sliding the sliders 7 on the slide rails 8, the damper movable section 4 can be telescopic relative to the damper fixed section 5.

[0050] In this embodiment, the slide rail 8 is fixed to the damper fixed section 5, and the damper moving section 4 is connected to the actuator 2 through a ball hinge as described later. The present invention can replace the rotation of the actuator 2 itself with the movement between the damper fixed section 5 and the damper moving section 4, so that the actuator 2 only needs to perform linear motion without rotation.

[0051] In addition, limiting members such as bumps may be provided at both ends of the slide rail 8 to play a mechanical limiting role, for limiting the maximum position of the extension or shortening of the damper moving section 4 , that is, limiting the telescopic range of the damper moving section 4 .

[0052] Of course, the structure in which the damper moving section 4 slides relative to the damper fixed section 5 is not limited thereto, and there are many structural forms of the slide rail and the slider. Figure 5 This is only one typical combination mode, as long as the damper moving section 4 can slide relative to the damper fixed section 5. For example, a slider can be provided on the damper fixed section 5, and a slide rail can be provided on the damper moving section 4. That is, a slide rail can be provided on one of the damper fixed section 5 and the damper moving section 4, and a slider that can slide on the slide rail can be provided on the other.

[0053] like Figure 2 - Figure 3 As shown, the actuator 2 passes through the air intake duct 1 and acts on the air intake damper 10 to open or close the air intake damper 10. In this embodiment, the actuator 2 has an actuating rod 9, which is connected to the damper moving section 4 through a ball hinge, and the damper moving section 4 is extended and retracted as the actuating rod 9 is extended and retracted. When the air intake damper 10 is opened, the actuating rod 9 of the actuator 2 is extended, and the sliders 7 on both sides of the damper moving section 4 are extended along the slide rails 8 on both sides of the damper fixed section 5. On the contrary, when the air intake damper 10 is closed, the actuating rod 9 of the actuator 2 is shortened, and the sliders 7 on both sides of the damper moving section 4 are shortened along the slide rails 8 on both sides of the damper fixed section 5.

[0054] That is, during the process of opening or closing the air intake damper 10, the actuating rod 9 of the actuator 2 is extended or shortened, and the damper moving section 4 is extended / shortened relative to the damper fixed section 5. During this process, the actuator 2 does not need to rotate.

[0055] The flange on the housing of the actuator 2 is connected to the actuator fixing boss 3 of the air intake duct 1 by fasteners such as screws. At this time, the material and thickness of the actuator fixing boss 3 and the type and spacing of the fasteners meet the fire test requirements specified in AC20-135 (Federal Aviation Administration regulations of the United States), and detailed description is omitted here.

[0056] The actuator 2 passes through the air inlet 1, and a fireproof seal is required at the penetration point. In this embodiment, since the actuator 2 does not need to rotate, a fixed form (connected by fasteners) can be used for fireproof sealing. Therefore, the fireproof requirements of the actuator 2 can be met by a simple metal connection structure, without the need to set flexible parts such as fireproof covers or rubber seals.

[0057] (Technical Effects of Embodiments of the Invention)

[0058] (1) The present invention provides a retractable air intake damper 10, that is, the air intake damper 10 includes a damper fixed section 5 and a damper movable section 4 that can be retracted relative to the damper fixed section 5. Therefore, the length of the air intake damper 10 can be increased without changing the opening 11 of the aircraft skin 6, which is beneficial for the air intake damper 10 to capture the incoming flow, improve the APU intake / ventilation total pressure recovery coefficient, and improve the APU air starting performance.

[0059] (2) The actuation mode of the air intake damper 10 in the present invention is such that the actuator 2 does not need to rotate during the actuation process. Therefore, the fire protection requirements for cabin penetration can be met through a simple metal connection structure, saving parts such as metal covers.

[0060] (3) The air intake damper 10 proposed by the present invention is an optimization of the common air intake damper. There is no need to change the structure of the aircraft body. It only needs to replace the existing air intake damper with a retractable air intake damper 10. It is easy to implement on existing aircraft and has strong practicality.

[0061] (Variation Example)

[0062] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned embodiments.

[0063] (1) In the above-mentioned embodiment, the damper movable section 4 overlaps with the damper fixed section 5 inside, and the length of the damper movable section 4 is shorter than the length of the damper fixed section 5. When the air intake damper 10 is closed, the damper fixed section 5 closes the opening 11. However, it is not limited to this. As long as the air intake damper 10 includes the damper fixed section 5 and the damper movable section 4, the length of the air intake damper 10 when the opening 11 is opened is formed to be longer than the length of the air intake damper 10 when the opening 11 is closed.

[0064] (2) The damper moving section 4 only needs to be able to extend and retract relative to the damper fixed section 5, and the extension method is not limited to sliding, and other methods may be used.

[0065] Although the structure and working principle of the present invention are described above in conjunction with the preferred embodiments, it should be recognized by those skilled in the art that the above examples are only for illustration and cannot be used as limitations of the present invention. Therefore, the present invention can be modified and varied within the spirit of the claims, and these modifications and variations will fall within the scope required by the claims of the present invention.

Claims

1. An APU air intake damper system, comprising: Airway; an air intake damper for opening or closing the air passage; as well as an actuator for opening or closing the intake damper, It is characterized in that The air intake damper comprises a damper fixed section and a damper movable section capable of extending and retracting relative to the damper fixed section. When the air intake damper is closed, the actuator retracts the damper moving section relative to the damper fixed section to shorten the overall length of the air intake damper. When the air intake damper is opened, the actuator causes the damper moving section to extend relative to the damper fixed section to increase the overall length of the air intake damper.

2. The APU air intake damper system according to claim 1, characterized in that: The damper moving section achieves extension and retraction relative to the damper fixed section by sliding relative to the damper fixed section.

3. The APU air intake damper system according to claim 2, characterized in that: A slide rail is arranged on the damper fixed section, and a slide block capable of sliding on the slide rail is arranged on the damper movable section.

4. The APU air intake damper system according to claim 3, characterized in that: Limiting members are arranged at both ends of the slide rail, and the limiting members are used to limit the telescopic range of the damper moving section.

5. The APU air intake damper system according to claim 1, characterized in that: The actuator has an actuating rod. The actuating rod is connected to the damper moving section through a ball hinge, and the damper moving section is extended and retracted along with the extension and retraction of the actuating rod.

6. The APU air intake damper system according to claim 1, characterized in that: An actuator fixing boss for fixing the actuator is arranged in the air inlet passage, and a flange on the housing of the actuator is connected to the actuator fixing boss via a fastener.

Images