A grid drag reduction mode switching valve in an adaptive cycle engine adjustable mechanism

Abstract

The present invention relates to a grid drag reduction mode switching valve in an adjustable mechanism of an adaptive cycle engine. The mode switching valve is located in the second outer conduit of the engine and is driven by a hydraulic actuator. The sealing is achieved using a sealing strip and a load-bearing frame installed on the casing, thereby opening and closing the airflow passage of the second outer conduit, changing the flow distribution between the first outer conduit and the second outer conduit, and thus switching the engine operating mode. The mode switching valve is applied to a wide-range adaptive cycle engine and adopts an "upwind" placement direction that is different from that of traditional adaptive cycle engines. In order to reduce the aerodynamic drag and instability risk caused by the "upwind" placement, an innovative grid drag reduction design scheme is adopted. The mechanism has a reasonable design, reliable movement, and good airtightness.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-performance gas turbine engines in aerospace technology, and in particular relates to a grid drag reduction mode switching valve in an adjustable mechanism of an adaptive cycle engine. Background Art

[0002] An adaptive cycle engine means that the engine can adjust its thermodynamic cycle mode according to different working conditions, so that the engine can meet the performance requirements under different external environments and different flight missions.

[0003] The adaptive cycle engine uses a three-bypass mode. Adjustable mechanisms such as a mode switching valve, variable duct ejector, and adjustable guide vanes adjust the engine's bypass ratio, turbine inlet temperature, and boost ratio, enabling the engine to achieve optimal performance over a wider operating range. The mode switching valve, located in the second bypass, is used to open and close the airflow path of the second bypass, enabling the engine to switch between turbojet and turbofan modes. Unlike the "downwind" placement of the mode switching valve in conventional variable cycle engines (such as CN201410168812 and CN200910091284), the mode switching valve in the adaptive cycle engine is placed "upwind." This structural design requirement results in the mode switching valve being subject to significant aerodynamic resistance during mode switching and prone to instability. Summary of the Invention

[0004] To address the aforementioned technical issues, the present invention provides a grid-type drag-reducing mode switching valve in the adjustable mechanism of an adaptive cycle engine. During engine operating mode switching, the mode switching valve can open the grid, creating an airflow path to reduce aerodynamic drag and the risk of structural instability. This reduces the structural strength design requirements of the mode switching valve and reduces its volume and mass. This mode switching valve is positioned "upwind," allowing the grid to open during mode switching, reducing aerodynamic drag on the mode switching valve while also exhibiting good structural stability and airtightness.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A grid-type drag-reducing mode switching valve in the adjustable mechanism of an adaptive cycle engine is located between the first and second outer shrouds of the engine. It consists of a second outer shroud outer casing, a second outer shroud front inner casing, a second outer shroud rear inner casing, a synchronizer ring, a hydraulic actuator, a grid support frame, a grid, a synchronizer rod, a transmission rod, a slider, a guide rail, a synchronizer ring support, and a sealing strip. The inner wall of the second outer shroud rear inner casing has 48 pairs of first lugs for mounting the grid support frame. The sides and top of the grid support frame are wrapped with rubber sealing strips to improve the airtightness of the mode switching valve. The grid support frame has a first pin hole on its side, and the grid also has a second pin hole. The first and second pins connect the grid to the grid support frame, allowing the grid to rotate.

[0007] Furthermore, the grids are streamlined to reduce aerodynamic drag during mode switching. Each grid is fitted with a fourth lug on its side, connecting it to a synchronization rod that ensures consistent rotation of each grid. The leading edge grid also features a circular first-arc boss. In turbofan mode, this first-arc boss presses against the inner casing at the front of the second outer casing, limiting rotation of the leading edge grid. The synchronization rod allows the grids to rotate synchronously, forcing a tight seal between them.

[0008] Furthermore, a third lug is provided at the front end of the grid support frame, connected to a sixth lug on the synchronizer ring via a transmission rod. The synchronizer ring is mounted on the inner casing of the rear section of the second outer culvert. The slider is fixed to the synchronizer ring via four screws. The slider moves axially along a guide rail fixed to the synchronizer ring support, which is screwed to the inner casing of the rear section of the second outer culvert.

[0009] Furthermore, the hydraulic actuator drives the synchronizer ring to slide back and forth. The hydraulic actuator consists of a ball joint, an actuator rod, and a cylinder body. The front end of the actuator rod is provided with a fifth lug, which is connected to the actuator connecting column on the synchronizer ring through a ball joint. The outer casing of the second outer casing is provided with a load-bearing frame and a second arc boss: the load-bearing frame is connected to the inner casing of the rear section of the second outer casing by welding. In addition to transmitting load and supporting the engine, it can also achieve the sealing of the mode switching valve in the turbojet working mode of the engine; in the turbojet working mode, the second arc boss is pressed tightly against the frontmost grid, limiting the rotation of the frontmost grid. Through the synchronization rod, the grids rotate synchronously, so that the grids are pressed and sealed against each other, which is consistent with the function of the first arc boss on the frontmost grid.

[0010] Furthermore, five grids are installed on the grid support frame.

[0011] Furthermore, the synchronization ring is provided with two sliders, which are driven by two hydraulic actuators.

[0012] The advantages of the present invention compared with the prior art are:

[0013] The present invention discloses a grid-type drag-reducing mode switching valve in the adjustable mechanism of an adaptive cycle engine. This mechanism utilizes a grid structure to achieve drag reduction during the mode switching process, while meeting the basic requirements of opening and closing the duct and switching the engine's operating mode. This is particularly true when switching from turbojet to turbofan mode, where the mode switching valve must be pushed forward against the wind, subjecting it to significant aerodynamic resistance. This mechanism significantly reduces the drag experienced by the mode switching valve during this process, thereby lowering the requirements for structural strength and drive system, and achieving a lightweight structure. Furthermore, the structure offers reliable movement and excellent airtightness. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1a 、 Figure 1b 、 Figure 1c They are respectively a cross-sectional view, a triaxial view and a front view of the turbojet working mode of the present invention;

[0015] Figure 2a 、 Figure 2b 、 Figure 2c They are respectively a cross-sectional view, a triaxial view and a front view of an intermediate state during the mode switching process of the present invention;

[0016] Figure 3a 、 Figure 3b 、 Figure 3c They are respectively a cross-sectional view, a triaxial view and a front view of the turbojet working mode of the present invention;

[0017] Figure 4 This is a schematic diagram of the connection between the hydraulic actuator and the synchronizer ring of the present invention;

[0018] Figure 5 This is a schematic diagram of the hydraulic actuator of the present invention;

[0019] Figure 6 This is a schematic diagram of the synchronization ring of the present invention;

[0020] Figure 7 It is a schematic diagram of the slider of the present invention;

[0021] Figure 8 This is a schematic diagram of the synchronizer ring support of the present invention;

[0022] Figure 9 Schematic diagram of the guide rail of the present invention;

[0023] Figure 10 This is a schematic diagram of the rear end inner casing of the second outer casing of the present invention;

[0024] Figure 11a 、 Figure 11b 、 Figure 11c It is a schematic diagram of the assembly of the grid structure of the present invention;

[0025] Figure 12 This is a schematic diagram of the second outer casing of the present invention. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0027] like Figure 1a , Figure 1b , Figure 1c 、 Figure 2a 、 Figure 2b 、 Figure 2c 、 Figure 3a 、 Figure 3b 、 Figure 3c The figure shows the cross-sectional view, orthometric view, and front view of the grid drag reduction mode switching valve in three conditions: turbojet operating mode, intermediate state during mode switching, and turbofan operating mode. The grid drag reduction mode switching valve consists of a second outer casing 1, a second outer casing front section inner casing 2, a second outer casing rear section inner casing 3, a synchronizer ring 4, a hydraulic actuator 5, a grid support frame 6, a grid 7, a synchronizer rod 8, a transmission rod 9, a slider 10, a guide rail 11, a synchronizer ring support 12, and a sealing strip 13. The connection method of each component is as follows: Figure 4-12 As shown. The inner wall of the rear section of the second outer culvert's inner casing 3 has several pairs of first lugs 3-2 for mounting a grid support frame 6. Five rotatable grids 7 are mounted on this frame, connected by synchronization rods 8 to ensure consistent rotation. The grid support frame 6 is connected to a synchronizer ring 4 via a transmission rod 9. The synchronizer ring 4 slides back and forth along the rear section of the second outer culvert's inner casing 3, driven by a hydraulic actuator 5. The main moving parts include the synchronizer ring 4, hydraulic actuator 5, grid support frame 6, grids 7, synchronization rod 8, and transmission rod 9. The hydraulic actuator 5 provides power, driving the synchronizer ring 4's axial movement. The 24 transmission rods 9 connected to the synchronizer ring 4 rotate the grid support frame 6, opening and closing the second outer culvert and switching the engine's operating modes.

[0028] like Figure 1a-Figure 1c As shown: the engine is in turbojet working mode, the hydraulic actuator 5 moves backward along the airflow direction until the grid support frame 6 contacts the second outer casing 1, and the second outer casing flow channel is closed. Figure 2a-2c As shown: When the engine is in the process of mode switching, the grid 7 is affected by the second external airflow, and the grid 7 will automatically open to form an airflow path, greatly reducing the aerodynamic resistance received by the mode switching valve. Figure 3a-3c As shown, the hydraulic actuator 5 moves forward along the airflow direction until the grid support frame 6 contacts the inner casing 2 of the front section of the second outer duct, and the second outer duct flow channel is opened.

[0029] like Figure 4 、 Figure 5 Figure 2 shows the connection between the hydraulic actuator 5 and the synchronizer ring 4. The synchronizer ring 4 is equipped with an actuator connecting post 4-1, which is fitted with a ball joint 5-1. The ball joint 5-1 connects to the actuator 5 via a fifth lug 5-4 on the actuator rod 5-2. Hydraulic oil in the actuator body 5-3 drives the actuator rod 5-2, causing the synchronizer ring 4 to move forward and backward along the engine axis.

[0030] like Figure 6 As shown, the synchronizer ring 4 is designed with four grooves. Two of these grooves are equipped with actuator connecting posts 4-1. The other two grooves each have four first threaded holes 4-3 for mounting the slider 10. The first threaded holes 4-3 and the actuator connecting posts 4-1 are distributed along the circumference. Twenty-four sixth lugs 4-2 are evenly distributed on the side of the synchronizer ring for mounting the transmission rod 9.

[0031] like Figure 7 As shown, the guide rail 11 is a simple cylinder.

[0032] like Figure 8 As shown, the slider 10 is a standard box-type linear slider with four bolt holes 10-1 for connecting with the first threaded holes 4-3 on the synchronizer ring 4. The guide rail 11 passes through the through hole 10-2 inside the slider to achieve the four-axial sliding of the synchronizer ring.

[0033] like Figure 9 As shown, the synchronizer ring support 12 is a T-shaped member with a second threaded hole 12-2 on each side of the bottom for connecting and fixing with the second outer culvert rear section inner casing 3. The synchronizer ring support 12 has a through hole 12-1 at its upper end for fixing with the guide rail 11.

[0034] like Figure 10 As shown, the second outer culvert rear section inner casing 3 has eight third threaded holes 3-1 for mounting and securing the synchronizer ring support 12. The inner wall of the second outer culvert rear section inner casing 3 is provided with 48 pairs of first lugs 3-2 for mounting and connecting the grid support frame 6. The grid support frame 6 and the second outer culvert rear section inner casing 3 are connected by pins, allowing the grid support frame 6 to rotate relative to the second outer culvert rear section inner casing 3.

[0035] like Figure 11a , Figure 11b , Figure 11cAs shown, the rear end of the grid support frame 6 is equipped with two second lugs 6-1 for connecting to the inner casing 3 of the rear section of the second outer culvert; the front end also has a third lug 6-3 for connecting to the transmission rod 9. The inside of the grid support frame 6 is provided with five pairs of first pin holes 6-2 for mounting the grids 7. The outside of the grid support frame 6 is wrapped with a rubber sealing strip 13 to enhance airtightness. Five grids 7 are mounted on each grid support frame 6. The grids 7 are designed to be streamlined to further reduce resistance during mode switching. Second pin holes 7-6 are provided on the sides of the grids 7 for connecting the grids 7 to the grid support frame 6. Each grid 7 is provided with a fourth lug 7-7 to connect to the synchronization rod 8, and the synchronization rod 8 makes the rotation angles of each grid 7 consistent. The front edge grid 7-1 is also provided with a first arc boss 7-8, so that when the engine is in the turbofan working mode, the first arc boss 7-8 contacts the inner casing 2 at the front end of the second outer casing, and the grids 7 are pressed and locked against each other to prevent the grids 7 from opening and causing air leakage.

[0036] like Figure 12 As shown, the second outer casing 1 is equipped with 24 load-bearing frames 1-1. These frames 1-1 are welded to the rear inner casing 3 of the second outer casing, transmitting load while ensuring a tight seal for the mode switching valve in the engine's turbojet mode. The second outer casing 1 is also equipped with 24 second circular bosses 1-2. In turbojet mode, these second circular bosses 1-2 contact the leading edge grids 7-1, compressing and locking the grids 7 together to prevent air leakage.

[0037] The scope of the present invention is defined by the appended claims, and all equivalent substitutions and modifications made without departing from the spirit and principles of the present invention should be included within the scope of the present invention.

Claims

1. A grid drag reduction mode switching valve in an adaptive cycle engine adjustable mechanism, characterized by: The mode switching valve is located between the first outer culvert and the second outer culvert of the engine, and comprises a second outer culvert outer casing (1), a second outer culvert front section inner casing (2), a second outer culvert rear section inner casing (3), a synchronizer ring (4), a hydraulic actuator (5), a grid support frame (6), a grid (7), a synchronizer rod (8), a transmission rod (9), a slider (10), a guide rail (11), a synchronizer ring support (12), and a sealing strip (13); the inner wall of the second outer culvert rear section inner casing (3) is provided with a plurality of pairs of first lugs (3-2) for mounting the grid support frame (6); the grid support frame (6) is provided with five rotatable grids (7); the grids (7) are connected by synchronizer rods (8) to ensure the same rotation angle; the grid support frame (6) is connected by a transmission rod ... The actuator rod (9) is connected to the synchronizer ring (4), and the synchronizer ring (4) slides forward and backward along the inner casing (3) installed on the rear section of the second outer casing and is driven by a hydraulic actuator cylinder (5); the hydraulic actuator cylinder (5) is composed of a ball joint (5-1), an actuator cylinder pull rod (5-2) and a cylinder body (5-3); the hydraulic actuator cylinder (5) is connected to the actuator cylinder connecting column (4-1) on the synchronizer ring (4) through the fifth lug (5-4) at the front end of the actuator cylinder pull rod (5-2) and the ball joint (5-1); when the hydraulic actuator cylinder (5) drives the synchronizer ring (4) to move toward the engine intake direction, the second outer casing opens and the engine switches to a turbofan working mode; when the hydraulic actuator cylinder (5) drives the synchronizer ring (4) to move in the reverse direction, the second outer casing closes and the engine switches to a turbojet working mode; When the second outer casing of the engine is closed and in turbojet working mode, the gaps created by the outward expansion of the grid support frame (6) are filled with the support frame (1-1) of the outer casing (1) of the second outer casing to achieve gas sealing; The frontmost grid (7-1) of the grid (7) is provided with a first arc boss (7-8), and the second outer casing (1) is provided with a second arc boss (1-2), ensuring that the grid (7) is fixed and locked without rotating in both turbojet and turbofan operating modes of the engine.

2. The grid drag reduction mode switching valve in the adaptive cycle engine adjustable mechanism according to claim 1, characterized in that: The main structure of the mode switching valve is installed in the rear section of the second outer casing (3) in an "upwind" placement direction. When the engine switches from a turbojet working mode to a turbofan working mode, the mode switching valve moves forward in the direction of the upwind flow. The main structure includes a grid support frame (6), a grid (7), a synchronization rod (8), and a transmission rod (9).

3. The grid drag reduction mode switching valve in the adaptive cycle engine adjustable mechanism according to claim 1, characterized in that: The grid (7) adopts a streamlined design and can rotate on the grid support frame (6), which opens the air flow path during the mode switching process and reduces the aerodynamic resistance during the mode switching process.

4. The grid drag reduction mode switching valve in the adaptive cycle engine adjustable mechanism according to claim 1, characterized in that: The grid support frame (6) is provided with rubber sealing strips (13) on the side and top surfaces to reduce air leakage of the mode switching valve and improve the working efficiency of the engine.

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