A variable-sweep rotor blade

Abstract

The invention discloses a variable-sweep rotor blade, which relates to the field of helicopters, and includes a fixed blade, a movable blade, a connecting rod, a sleeve, a piston, a pneumatic pipeline, a compressed air assembly and an air suction assembly. The movable blade is hinged to the lower part of the fixed blade, the sleeve is fixed to the upper part of the fixed blade, the piston is slidably mounted on one end of the sleeve, the two ends of the connecting rod are respectively hinged to the outer end of the piston and the upper end of the movable blade, the other end of the sleeve is connected to the pneumatic pipeline, the compressed air assembly and the air suction assembly are both connected to the end of the pneumatic pipeline away from the sleeve, and the compressed air assembly and the air suction assembly are used to drive the piston to reciprocate relative to the sleeve, and then drive the movable blade to rotate relative to the fixed blade through the connecting rod. The variable-sweep rotor blade in the invention can achieve effective control of high-speed pulse noise while greatly reducing the occurrence of flutter during flight.

Description

Technical Field

[0001] The invention relates to the field of helicopters, in particular to a variable-sweep rotor blade. Background Art

[0002] Helicopters have a unique way of vertical take-off and landing and the ability to hover in the air, so they play an indispensable role in urban transportation, rescue and disaster relief missions, battlefield reconnaissance and operations, etc. However, the unique working mode of helicopter rotors is to provide the required lift through rotation, which causes them to be affected by the forward flight speed during forward flight. The aerodynamic noise of the rotor mainly includes thickness noise and load noise, which are the aerodynamic noise caused by the rotor expelling air and the aerodynamic changes generated by the rotor. Since the rotor rotation frequency is relatively low, the noise generated has the characteristics of low frequency and high intensity, resulting in long propagation distance and serious sound pollution. When the helicopter flies forward at a high speed, shock waves appear on the blades, generating high-intensity HSI noise, which is a type of load noise.

[0003] The prior art generally solves this problem by adopting a swept approach, that is, using a fixed swept wing with an unchanged structure to reduce the generation of shock waves and thus reduce HSI noise. However, the center of gravity of the fixed swept wing is different from that of an ordinary unswept airfoil. Therefore, when the fixed swept wing is used on a helicopter, flutter will occur due to the change in the center of gravity. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a variable-sweep rotor blade, which can effectively control high-speed pulse noise and greatly reduce flutter during flight.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a variable-sweep rotor blade, comprising a fixed blade, a movable blade, a connecting rod, a sleeve, a piston, an air pressure pipeline, an air compression component and an air suction component, wherein the movable blade is hinged to the lower part of the fixed blade, the sleeve is fixed to the upper part of the fixed blade, the piston is slidably installed at one end of the sleeve, the two ends of the connecting rod are respectively hinged to the outer end of the piston and the upper end of the movable blade, the other end of the sleeve is connected to the air pressure pipeline, the air compression component and the air suction component are both connected to one end of the air pressure pipeline away from the sleeve, the air compression component and the air suction component are used to drive the piston to reciprocate relative to the sleeve, and then drive the movable blade to rotate relative to the fixed blade through the connecting rod.

[0007] Preferably, a limiting component is provided in the sleeve, and the limiting component is used to prevent the piston from escaping from the sleeve.

[0008] Preferably, the lower part of the piston is provided with a strip groove extending along the length direction, the strip groove passes through the outer end of the piston but not through the inner end of the piston, the limiting component is a limiting block, the limiting block is arranged in the lower part of the sleeve away from one end of the air pressure pipe, and the limiting block is located in the strip groove.

[0009] Preferably, a first connecting plate is provided at the outer end of the piston, one end of the connecting rod is hinged to the first connecting plate, and the connecting rod is located in the strip groove.

[0010] Preferably, a second connecting plate is provided in the middle of the upper end of the movable blade, and the other end of the connecting rod is hinged to the second connecting plate.

[0011] Preferably, the fixed paddle includes a first panel and a second panel, the left and right ends of the first panel are respectively connected to the left and right ends of the first panel, there is a gap between the first panel and the second panel, a pin shaft is fixed at the lower part between the first panel and the second panel, and a pin hole matching the pin shaft is provided at the upper part of the movable paddle.

[0012] Preferably, the movable blade includes an upper fan-shaped blade plate, an upper blade plate, a lower blade plate and a lower fan-shaped blade plate, the upper blade plate is arranged on one side of the upper fan-shaped blade plate, and the upper fan-shaped blade plate is located below the piston, the upper blade plate is located below the air pressure pipe, the lower blade plate is arranged at the lower end of the upper fan-shaped blade plate, the lower fan-shaped blade plate is arranged on one side of the lower blade plate and at the lower end of the upper blade plate, the pin hole is formed at the joint of the upper fan-shaped blade plate, the upper blade plate, the lower blade plate and the lower fan-shaped blade plate, and the upper fan-shaped blade plate and the lower fan-shaped blade plate are used to fit with the inner wall of the fixed blade during the rotation of the movable blade.

[0013] Preferably, the compressed air component includes a compressed air pipeline, a compressed air component, a compressed air valve and a first pressure sensing component, the two ends of the compressed air pipeline are respectively connected to the air pressure pipeline and the compressed air component, the compressed air valve and the first pressure sensing component are both arranged on the compressed air pipeline, and the air intake component includes an air intake pipeline, an air intake component, an air intake valve and a second pressure sensing component, the two ends of the air intake pipeline are respectively connected to the air pressure pipeline and the air intake component, the air intake valve and the second pressure sensing component are both arranged on the air intake pipeline.

[0014] Preferably, the air compression valve is located between the first pressure sensing component and the air compression component, and the air suction valve is located between the second pressure sensing component and the air suction component.

[0015] Preferably, the air-compressing component is an air-compressing air pump, the air-inhaling component is an air-inhaling air pump, the first pressure sensing component is a first pressure sensor, and the second pressure sensing component is a second pressure sensor.

[0016] Compared with the prior art, the present invention has achieved the following technical effects:

[0017] The variable swept rotor blade provided by the present invention comprises a fixed blade, a movable blade, a connecting rod, a sleeve, a piston, a pneumatic pipeline, a compressed air assembly and an air suction assembly, wherein the movable blade is hinged to the lower part of the fixed blade, the piston is slidably mounted on one end of the sleeve, the two ends of the connecting rod are respectively hinged to the outer end of the piston and the upper end of the movable blade, the other end of the sleeve is connected to the pneumatic pipeline, and the compressed air assembly and the air suction assembly are used to drive the piston to reciprocate relative to the sleeve, and then drive the movable blade to rotate relative to the fixed blade through the connecting rod. Initially, it is in a non-swept state. When the forward speed of the helicopter is relatively large, the compressed air assembly inflates the sleeve, and the air pressure pushes the piston to move outward, that is, the piston is extended, driving the connecting rod to rotate the movable blade backward, so that the movable blade is swept relative to the fixed blade, thereby realizing effective control of high-speed pulse noise; when the forward speed of the helicopter is relatively small, the movable blade does not need to be swept back at this time, the air suction assembly sucks air from the sleeve, and the negative pressure drives the piston to move inward, that is, the piston contracts, driving the connecting rod to rotate the movable blade forward, and returning to the initial state. The variable swept rotor blades of the present invention are only controlled to sweep back when flying forward at high speed or when shock waves appear on the forward side of the blades, thereby reducing the influence caused by the change of the center of gravity of the rotor blades, thereby greatly reducing the occurrence of flutter during flight. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of the structure of a variable-sweep rotor blade provided by the present invention;

[0020] Figure 2 A schematic diagram of the structure of a fixed blade in a variable-sweep rotor blade provided by the present invention;

[0021] Figure 3 A schematic diagram of the structure of a movable blade in a variable-sweep rotor blade provided by the present invention;

[0022] Figure 4 A schematic diagram of the structure of a sleeve and an air pressure duct in a variable-sweep rotor blade provided by the present invention;

[0023] Figure 5 A schematic diagram of the structure of a piston in a variable-sweep rotor blade provided by the present invention;

[0024] Figure 6 A schematic diagram of the installation of a connecting rod, a piston, a sleeve and an air pressure pipe in a variable-sweep rotor blade provided by the present invention;

[0025] Figure 7 A schematic diagram of the working of the compressor assembly in the variable-sweep rotor blade provided by the present invention;

[0026] Figure 8 A schematic diagram of the operation of an air intake assembly in a variable-sweep rotor blade provided by the present invention;

[0027] Fig. 9 A schematic diagram of the contraction state of the piston during air intake in the variable-sweep rotor blade provided by the present invention;

[0028] Fig.10 A schematic diagram of the extended state of the piston during air compression in the variable-sweep rotor blade provided by the present invention;

[0029] Fig.11 A schematic diagram of the attitude change of the variable-sweep rotor blade provided by the present invention.

[0030] Explanation of the reference numerals: 100, variable-sweep rotor blade; 1, fixed blade; 101, first panel; 102, second panel; 103, pin shaft; 2, movable blade; 201, upper fan-shaped blade plate; 202, upper blade plate; 203, lower blade plate; 204, lower fan-shaped blade plate; 205, pin hole; 3, connecting rod; 4, sleeve; 5, piston; 6, air pressure pipeline; 7, compressed air pipeline; 8, compressed air component; 9, compressed air valve; 10, first pressure sensing component; 11, suction pipeline; 12, suction component; 13, suction air valve; 14, second pressure sensing component; 15, first connecting plate; 16, second connecting plate; 17, strip groove; 18, limit block; 19, accommodating groove. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The object of the present invention is to provide a variable-sweep rotor blade, which can effectively control high-speed pulse noise and greatly reduce the occurrence of flutter during flight.

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] like Figure 1-Figure 11 As shown, this embodiment provides a variable-sweep rotor blade 100, including a fixed blade 1, a movable blade 2, a connecting rod 3, a sleeve 4, a piston 5, an air pressure pipe 6, a compressed air assembly and an air suction assembly. The movable blade 2 is hinged to the lower part of the fixed blade 1, and the sleeve 4 is fixed to the upper part of the fixed blade 1. The sleeve 4 in this embodiment is arranged horizontally, and the piston 5 is slidably mounted on one end of the sleeve 4. The two ends of the connecting rod 3 are respectively hinged to the outer end of the piston 5 and the upper end of the movable blade 2. The other end of the sleeve 4 is connected to the air pressure pipe 6. The compressed air assembly and the air suction assembly are both connected to the end of the air pressure pipe 6 away from the sleeve 4. The compressed air assembly and the air suction assembly are used to drive the piston 5 to reciprocate relative to the sleeve 4, and then drive the movable blade 2 to rotate relative to the fixed blade 1 through the connecting rod 3. Specifically, the compressed air assembly is used to inflate the sleeve 4, and the air suction assembly is used to inhale air from the sleeve 4.

[0035] Initially, it is in a non-swept state. When the helicopter advances at a high speed, the air compressor assembly inflates the sleeve 4, and the air pressure pushes the piston 5 to move outward, that is, the piston 5 extends, driving the connecting rod 3 to rotate the movable blade 2 backward, so that the movable blade 2 is swept relative to the fixed blade 1, realizing the transformation from the ordinary airfoil to the swept airfoil. By changing the rotor blade attitude, the high-speed pulse noise is effectively controlled; when the helicopter advances at a low speed, the movable blade 2 does not need to be swept, and the air suction assembly inhales air from the sleeve 4, and the negative pressure drives the piston 5 to move inward, that is, the piston 5 contracts, driving the connecting rod 3 to rotate the movable blade 2 forward, and restore to the initial state. The variable swept rotor blade 100 in this embodiment only controls the movable blade 2 to be swept backward when flying forward at high speed, that is, when flying forward at high speed, the rotor blade is in a non-swept state, and the non-swept state will not cause flutter due to the change of the center of gravity, thereby reducing the influence caused by the change of the center of gravity of the rotor blade, so that the flutter during flight is greatly reduced. The variable-sweep rotor blade 100 in this embodiment utilizes air pressure to push the piston-connecting rod mechanism, thereby driving the movable blade 2 to rotate relative to the fixed blade 1, and the structure is simple and reliable.

[0036] Specifically, a limiting component is provided in the sleeve 4 , and the limiting component is used to limit the extension movement of the piston 5 , thereby preventing the piston 5 from escaping from the sleeve 4 .

[0037] like Figure 5 As shown, the lower part of the piston 5 is provided with a strip groove 17 extending along the length direction, and the strip groove 17 passes through the outer end of the piston 5 but does not pass through the inner end of the piston 5. Figure 4As shown, the limiting component is a limiting block 18, which is arranged at the lower part of the sleeve 4 away from one end of the air pressure pipe 6, and the limiting block 18 is located in the strip groove 17. When the piston 5 moves outward, the piston 5 will contact the limiting block 18 when it moves to a certain position, and the piston 5 cannot continue to move outward, that is, the limiting block 18 limits the extension movement of the piston 5.

[0038] like Figure 6 As shown, the outer end of the piston 5 is provided with a first connecting plate 15, one end of the connecting rod 3 is hinged to the first connecting plate 15, and the connecting rod 3 is located in the strip groove 17. Figure 4 As shown, a receiving groove 19 penetrating the outer end of the sleeve 4 is provided at the lower part of the end of the sleeve 4 away from the air pressure pipe 6. The receiving groove 19 corresponds to the position of the strip groove 17. When in the non-swept state, the connecting rod 3 is located in the receiving groove 19.

[0039] A second connecting plate 16 is provided in the middle of the upper end of the movable blade 2, and the other end of the connecting rod 3 is hinged to the second connecting plate 16, that is, one end of the connecting rod 3 is hinged to the outer end of the piston 5 through the first connecting plate 15, and the other end is hinged to the upper end of the movable blade 2 through the second connecting plate 16. In this embodiment, the other end of the connecting rod 3 is hinged to the upper end of the second connecting plate 16.

[0040] like Figure 2 As shown, the fixed blade 1 includes a first panel 101 and a second panel 102, the left and right ends of the first panel 101 are respectively connected to the left and right ends of the first panel 101, the upper and lower ends of the first panel 101 are not connected to the upper and lower ends of the second panel 102, there is a gap between the first panel 101 and the second panel 102, a pin shaft 103 is fixed at the lower part between the first panel 101 and the second panel 102, and a pin hole 205 matching the pin shaft 103 is provided at the upper part of the movable blade 2.

[0041] like Figure 3As shown, the movable blade 2 includes an upper fan-shaped blade plate 201, an upper blade plate 202, a lower blade plate 203 and a lower fan-shaped blade plate 204. The upper blade plate 202 is arranged on one side of the upper fan-shaped blade plate 201, and the upper fan-shaped blade plate 201 is located below the piston 5. The upper blade plate 202 is located below the air pressure pipe 6. The lower blade plate 203 is arranged at the lower end of the upper fan-shaped blade plate 201. The lower fan-shaped blade plate 204 is arranged on one side of the lower blade plate 203 and at the lower end of the upper blade plate 202. A pin hole 205 is formed at the joint of the upper fan-shaped blade plate 201, the upper blade plate 202, the lower blade plate 203 and the lower fan-shaped blade plate 204. The distance between the bottom end of the outer side of the upper fan-shaped blade plate 201 and the bottom end of the outer side of the upper blade plate 202 is equal to the distance between the left and right inner walls of the fixed blade 1. By setting the upper fan-shaped blade plate 201 and the lower fan-shaped blade plate 204, the movable blade 2 is prevented from being obstructed when rotating relative to the fixed blade 1. At the same time, the upper fan-shaped blade plate 201 and the lower fan-shaped blade plate 204 are used to fit with the inner wall of the fixed blade 1 during the rotation of the movable blade 2, so that the swept-back shape of the wing is smoother, the aerodynamic performance is better, and shock waves are not easily generated. The upper fan-shaped blade plate 201, the upper blade plate 202, the lower blade plate 203 and the lower fan-shaped blade plate 204 in this embodiment are an integrated structure.

[0042] like Figure 7 and Figure 8 As shown, the compressed air component includes a compressed air pipeline 7, a compressed air component 8, a compressed air valve 9 and a first pressure sensing component 10, the two ends of the compressed air pipeline 7 are respectively connected to the air pressure pipeline 6 and the compressed air component 8, the compressed air valve 9 and the first pressure sensing component 10 are both arranged on the compressed air pipeline 7, and the suction component includes an suction pipeline 11, an suction component 12, an suction air valve 13 and a second pressure sensing component 14, the two ends of the suction pipeline 11 are respectively connected to the air pressure pipeline 6 and the suction component 12, the suction air valve 13 and the second pressure sensing component 14 are both arranged on the suction pipeline 11.

[0043] The compressed air component 8, the compressed air valve 9, the first pressure sensing component 10, the air intake component 12, the air intake valve 13 and the second pressure sensing component 14 in this embodiment are all controlled by the control system on the helicopter. In addition, in addition to the automatic control of the above components by the control system of the helicopter, the above components can also be controlled manually, that is, when the forward speed is low and a shock wave appears on the forward side of the blade, the compressed air valve 9 is manually opened to realize the sweep of the movable blade 2. The active control means of real-time manual monitoring can be used, so that the variable swept rotor blade 100 in this embodiment can be adaptively applied to various flight environments.

[0044] In this specific embodiment, the air compression valve 9 is located between the first pressure sensing component 10 and the air compression component 8 , and the air suction valve 13 is located between the second pressure sensing component 14 and the air suction component 12 .

[0045] In this specific embodiment, the air-compressing component 8 is an air-compressing air pump, the air-inhaling component 12 is an air-inhaling air pump, the first pressure sensing component 10 is a first pressure sensor, and the second pressure sensing component 14 is a second pressure sensor.

[0046] The specific usage process is as follows: Figure 9-11 As shown, when the forward speed reaches Mach number 0.75, the relative speed of the blade tip increases and HSI noise is generated. At this time, the control system controls the compressed air valve 9 to open, and air enters the sleeve 4 through the air pressure pipe 6. The air pressure pushes the piston 5 to move outward, driving the connecting rod 3 to rotate the movable blade 2 backward; when the piston 5 moves to contact the limit block 18, the piston 5 stops moving under the action of the limit block 18. At this time, the movable blade 2 rotates to the extreme position. When the inflation continues, the first pressure sensing component 10 detects the increase in air pressure, and the control system controls the compressed air valve 9 to close. When the forward speed is less than Mach number 0.75, the relative speed of the blade tip decreases. At this time, the movable blade 2 does not need to be swept back. The control system controls the intake valve 13 to open, and air is sucked outward from the sleeve 4 through the air pressure pipe 6. The negative pressure drives the piston 5 to move inward, driving the connecting rod 3 to rotate the movable blade 2 forward; when the piston 5 moves to contact the end of the sleeve 4, the piston 5 stops moving under the restriction of the end face of the sleeve 4. At this time, the movable blade 2 rotates to the initial position, that is, the non-swept back state. When the air continues to be inhaled, the second pressure sensing component 14 detects a decrease in air pressure, and the control system controls the intake valve 13 to close.

[0047] The present specification uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A variable-sweep rotor blade, characterized in that: The invention comprises a fixed blade, a movable blade, a connecting rod, a sleeve, a piston, an air pressure pipeline, an air compression component and an air suction component, wherein the movable blade is hinged to the lower part of the fixed blade, the sleeve is fixed to the upper part of the fixed blade, the piston is slidably mounted on one end of the sleeve, the two ends of the connecting rod are respectively hinged to the outer end of the piston and the upper end of the movable blade, the other end of the sleeve is communicated with the air pressure pipeline, the air compression component and the air suction component are both communicated with the end of the air pressure pipeline away from the sleeve, the air compression component and the air suction component are used to drive the piston to reciprocate relative to the sleeve, and then drive the movable blade to rotate relative to the fixed blade through the connecting rod; the fixed blade comprises a first panel and a second panel, the left and right ends of the first panel are respectively connected to the left and right ends of the first panel, the first panel is connected to the There is a gap between the second panel, a pin shaft is fixed at the lower part between the first panel and the second panel, and a pin hole matching the pin shaft is arranged on the upper part of the movable blade; the movable blade comprises an upper fan-shaped blade plate, an upper blade plate, a lower blade plate and a lower fan-shaped blade plate, the upper blade plate is arranged on one side of the upper fan-shaped blade plate, and the upper fan-shaped blade plate is located below the piston, the upper blade plate is located below the air pressure pipe, the lower blade plate is arranged on the lower end of the upper fan-shaped blade plate, the lower fan-shaped blade plate is arranged on one side of the lower blade plate and at the lower end of the upper blade plate, the pin hole is formed at the joint of the upper fan-shaped blade plate, the upper blade plate, the lower blade plate and the lower fan-shaped blade plate, and the upper fan-shaped blade plate and the lower fan-shaped blade plate are used to fit with the inner wall of the fixed blade during the rotation of the movable blade.

2. The variable-sweep rotor blade according to claim 1, characterized in that: A limiting component is arranged in the sleeve, and the limiting component is used to prevent the piston from falling out of the sleeve.

3. The variable-sweep rotor blade according to claim 2, characterized in that: The lower part of the piston is provided with a strip groove extending along the length direction, the strip groove passes through the outer end of the piston but not through the inner end of the piston, the limiting component is a limiting block, the limiting block is arranged in the lower part of the sleeve away from one end of the air pressure pipe, and the limiting block is located in the strip groove.

4. The variable-sweep rotor blade according to claim 3, characterized in that: A first connecting plate is arranged at the outer end of the piston, one end of the connecting rod is hinged to the first connecting plate, and the connecting rod is located in the strip groove.

5. The variable-sweep rotor blade according to claim 4, characterized in that: A second connecting plate is provided in the middle of the upper end of the movable blade, and the other end of the connecting rod is hinged to the second connecting plate.

6. The variable-sweep rotor blade according to claim 1, characterized in that: The compressed air component includes a compressed air pipeline, a compressed air component, a compressed air valve and a first pressure sensing component, the two ends of the compressed air pipeline are respectively connected to the air pressure pipeline and the compressed air component, the compressed air valve and the first pressure sensing component are both arranged on the compressed air pipeline, and the air intake component includes an air intake pipeline, an air intake component, an air intake valve and a second pressure sensing component, the two ends of the air intake pipeline are respectively connected to the air pressure pipeline and the air intake component, the air intake valve and the second pressure sensing component are both arranged on the air intake pipeline.

7. The variable-sweep rotor blade according to claim 6, characterized in that: The air compression valve is located between the first pressure sensing component and the air compression component, and the air suction valve is located between the second pressure sensing component and the air suction component.

8. The variable-sweep rotor blade according to claim 6, characterized in that: The air-compressing component is an air-compressing air pump, the air-inhaling component is an air-inhaling air pump, the first pressure sensing component is a first pressure sensor, and the second pressure sensing component is a second pressure sensor.

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