Deflation grid and preparation method thereof

Abstract

The deflation grille is circumferentially assembled on the outer side of a casing and comprises a first wall surface, a first side surface, a second side surface, a third side surface, a plurality of longitudinal ribs and a plurality of guide vanes, and the first wall surface is of a curved surface structure with radian; the first side face, the second side face and the third side face are arranged on the circumferential left side, the circumferential right side and the axial rear side of the first wall face correspondingly. The plurality of longitudinal ribs are arranged on the first wall surface in a staggered manner to define a gap area; a plurality of guide vanes are located within the void area. The deflation grille can effectively dredge air flow of the inner duct of the engine to the outer duct. The invention further provides a preparation method of the deflation grid.

Description

Technical Field

[0001] The invention relates to the field of aviation engines, and in particular to the field of air discharge grilles. Background Art

[0002] The turbine engine has an intermediate unit body assembly, which includes an intermediate inner casing assembly, an outlet guide vane assembly, an intermediate outer casing assembly, etc. in order from radially outward. Multiple variable bleed valve system (VBV) bleed pipes are installed circumferentially on the outer side of the intermediate inner casing assembly. The engine inner duct airflow is discharged by the bleed valve, passes through the bleed pipe, and is combed by the bleed grille to the outer duct.

[0003] The development trend of modern aircraft engines is characterized by high bypass ratio, high thrust, low fuel consumption, low noise, high economy and high reliability. The application level of resin-based composite materials has become an important symbol of the advancement of aircraft engines due to their advantages of low density, high specific strength, high specific modulus, strong designability, fatigue resistance and excellent corrosion resistance. The use of resin-based composite materials can effectively reduce the weight of parts, thereby reducing the total weight of the engine and improving the engine propulsion efficiency. Summary of the invention

[0004] An object of the present invention is to provide an air discharge grille.

[0005] Another object of the present invention is to provide a method for preparing the air release grid.

[0006] To achieve the above-mentioned purpose, the air vent grille is circumferentially assembled on the outside of the casing, and includes a first wall, a first side surface, a second side surface, a third side surface, a plurality of longitudinal ribs and a plurality of guide vanes. The first wall is a curved surface structure with an arc; the first side surface, the second side surface and the third side surface are respectively arranged on the circumferential left side, the circumferential right side and the axial rear side of the first wall; a plurality of longitudinal ribs are staggeredly arranged on the first wall to define a gap area; and a plurality of guide vanes are located in the gap area.

[0007] In one or more embodiments, a plurality of guide vanes are arranged in parallel and perpendicular to the longitudinal ribs, and form an acute angle with the first wall surface.

[0008] In one or more embodiments, the acute angle defined by the guide vane and the first wall surface to which it is connected is in the range of 30 to 60 degrees.

[0009] In one or more embodiments, the guide vane is a curved structure with an arc.

[0010] In one or more embodiments, the first wall surface, the first side surface, and the second side surface are equal thickness structures, and the first side surface and the second side surface have the same thickness.

[0011] In one or more embodiments, a first bolt hole is disposed on the first wall surface, and second bolt holes are disposed on the first side surface and the second side surface.

[0012] In one or more embodiments, the first wall surface is a non-uniform thickness structure, including a main body portion and a thick wall portion, and the thick wall portion is located around the first bolt hole.

[0013] In one or more embodiments, the thickness of the main body portion is 4 mm to 8 mm, and the thickness of the thick-walled portion is 7 mm to 11 mm.

[0014] In one or more embodiments, the air discharge grille is a fiber reinforced thermoplastic resin-based composite material.

[0015] The method for preparing an air vent grille to achieve the above-mentioned purpose comprises the following steps: S1. manufacturing a hollow split mold of the same shape as the engine air vent grille, wherein the hollow mold is split along the circumference of the engine; S2. coating a release agent on the surface of the hollow split mold; S3. fixing one half of the hollow split mold, and fixing bolt hole inserts on the first wall, first side and second side of the air vent grille in the fixed half mold; S4. closing and fixing the hollow split mold, and preheating the mold to a certain temperature; S5. injecting composite material into the hollow split mold; S6. curing and molding the composite material, and demolding to obtain the part.

[0016] The above-mentioned air bleed grille is arranged on the outside of the intermediate inner casing assembly, corresponding to the outlet of the VBV air bleed pipe, and can effectively guide the airflow in the inner duct of the engine to the outer duct.

[0017] The composite material air release grille prepared by the above method has a light weight and a simple molding method, has good wear resistance and hard elasticity, and can play a buffering role. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0019] Figure 1A-1B It is a schematic diagram of the installation position of the air release grille;

[0020] Figure 2A-2B is a schematic diagram of an embodiment of an air vent grille;

[0021] Figure 3 It is a cross-sectional view along the AA direction in 2A;

[0022] Figure 4 is a flow chart of a method for preparing a venting grid. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0024] It should be noted that these and other subsequent drawings are only examples and are not drawn to scale, and should not be used to limit the actual scope of protection required by the present invention.

[0025] The following terms "axial" refer to the direction parallel to the engine rotation axis; "radial" refers to the radius direction of the intermediate inner casing assembly, and the plane in which it is located is perpendicular to the engine rotation axis; "circumferential" refers to the circumferential direction of the intermediate inner casing assembly, that is, the direction around the engine rotation axis; "front" refers to the direction along the axial direction of the engine close to the fan air inlet end after the air vent grille is assembled, such as the direction of the fan blades; "rear" refers to the direction along the axial direction of the engine away from the fan air inlet end after the air vent grille is assembled, such as the direction of the high-pressure compressor.

[0026] The intermediate unit body assembly of the turbine engine includes an intermediate inner casing assembly, an outlet guide vane assembly, an intermediate outer casing assembly, etc. in sequence from radially outward.

[0027] As reference Figure 1A and 1B It is understood that the radial outer side of the intermediate inner casing assembly 2 is provided with a support ring 7 along the circumferential direction, which is used to connect the bleed pipes 5 of multiple variable bleed valve systems (VBV), and install multiple bleed grilles (Vent Grille) 1. The radial inner side of the intermediate inner casing assembly 2 is provided with blades, which are arranged around the engine rotation axis 3. The front part of the bleed grille 1 is inserted into the lower edge plate area of ​​the outlet guide vane (GOV) 6. When the bleed valve 4 is opened, the airflow in the inner duct of the engine is discharged by the bleed valve 4, passes through the bleed pipe 5, and is combed by the bleed grille 1 to the outer duct. The outer duct is in Figure 1B It can be understood that it is the radial area where the outlet guide vane 6 is located, and the flow area of ​​the airflow is as shown in the direction P.

[0028] Continue to refer to Figure 1A The schematic diagram of the air venting grille 1 after assembly is shown, with the engine rotation axis 3 at the center, the intermediate inner casing assembly 2 surrounding the engine rotation axis 3, and the air venting grille 1 installed on the outer side of the intermediate inner casing assembly and arranged in sequence along the circumferential direction.

[0029] Figure 2A and Figure 2B A front view schematic diagram showing the air vent grille, Figure 3 Shown is the vent grille along Figure 2A Cross-sectional view in the AA direction.

[0030] The air discharge grille 1 comprises a first wall surface 10, a first side surface 11, a second side surface 12, a third side surface 13, a plurality of longitudinal ribs 14 and a plurality of guide vanes 15. The first wall surface 10 is a main structural surface of the grille having a plurality of guide vane structures, and the first side surface 11, the second side surface 12 and the third side surface 13 are respectively located on the circumferential left side, the circumferential right side and the axial rear side of the first wall surface 10.

[0031] The first wall 10 and the third side 13 are cambered surfaces. The longitudinal ribs 14 are located on the inner surface of the first wall 10, perpendicular to the first wall 10 and the first side 11, the second side 12, and the third side 13, defining a plurality of gap regions 107. A plurality of guide vanes 15 are disposed in the gap regions 107, parallel to each other, perpendicular to the plurality of longitudinal ribs 14, and forming a certain angle with the first wall 10. The first wall 10, the first side 11, the second side 12, the third side 13, and the plurality of longitudinal ribs 14 are all parallel to the axial direction of the engine, and the first wall 10 and the third side 13 are cambered surfaces, having a certain angle along the circumferential direction, such as Figure 1A shown.

[0032] Those skilled in the art will appreciate that the size and number of features of the air discharge grille 1 may be adjusted accordingly according to the operating conditions.

[0033] The specific parameter structure of the first embodiment of the air discharge grille is shown below.

[0034] The front end of the first wall surface 10 has a first bolt hole 105 and has a uniform thickness structure at all locations, with a thickness ranging from 4 mm to 8 mm, such as 7 mm.

[0035] The first side surface 11 and the second side surface 12 have second bolt holes 106, and the two are symmetrical about the center line of the grid. Each side surface is an equal thickness structure, and the first side surface 11 and the second side surface 12 have the same thickness, and the thickness range is 3mm to 7mm, such as 6mm.

[0036] The third side surface 13 is parallel to the first wall surface 10 and is a uniform thickness structure with a thickness of 1 mm to 5 mm, such as 4 mm.

[0037] The longitudinal ribs 14 are located on the inner surface of the first wall 10 and are perpendicular to the first wall 10 and the first side surface 11, the second side surface 12, and the third side surface 13. Five longitudinal ribs 14 are arranged side by side. Each rib is of equal thickness and has the same thickness, which is 3 mm to 7 mm, such as 6 mm.

[0038] The guide vanes 15 are planar structures and parallel to each other, arranged perpendicular to the longitudinal ribs 14, and have an angle of 45° with the first wall surface 10. There are two rows of guide vanes, each of which is of equal thickness and has the same thickness of 0.3 mm to 2 mm, such as 1 mm.

[0039] The specific parameter structure of the second embodiment of the air release grille is shown below.

[0040] The front end of the first wall 10 has a first bolt hole 105, and each part has a non-uniform thickness structure. The thickness of the main part 101 is 4mm-8mm, such as 6mm, and the thickness of the thick wall part 102 where the bolt hole is located is 7mm-11mm, such as 9mm.

[0041] The first side surface 11 and the second side surface 12 have second bolt holes 106, and the two are symmetrical about the center line of the grid. Each side surface is an equal thickness structure, and the first and second side surfaces have the same thickness, which is 3mm to 7mm, such as 5mm.

[0042] The third side surface 13 has a transition section 131 and a portion 132 parallel to the first wall surface. The portion 132 parallel to the first wall surface is a uniform thickness structure with a thickness of 1 mm to 5 mm, such as 3 mm.

[0043] The first wall surface 10 and the third side surface 13 are arc surfaces and have a certain angle along the circumferential direction.

[0044] The longitudinal ribs 14 are located on the inner surface of the first wall 10, perpendicular to the first wall 10 and the first side surface 11, the second side surface 12, and the third side surface 13, and the number is 4. Each rib is of equal thickness, and each rib may also have different thicknesses, such as Figure 3 As shown, the thickness of the two lateral ribs 141 close to the first side surface 11 and the second side surface 12 is 3 mm to 7 mm, such as 5 mm, and the thickness of the two internal ribs 142 that separate the guide vanes in the middle is 2 mm to 6 mm, such as 4 mm.

[0045] The guide vanes 15 have a curved surface structure with a certain curvature and are parallel to each other, perpendicular to the longitudinal ribs 14, and have an angle of 30° with the first wall surface. There are three rows of guide vanes, and each guide vane has an equal thickness structure and each vane has the same thickness, which is 0.3 mm to 2 mm, such as 0.6 mm.

[0046] The above-mentioned bleed grille installed on the outside of the inner casing assembly between the fan boost stage of the aircraft engine circumferentially corresponds to the VBV bleed pipe outlet, which can effectively guide the airflow in the inner duct of the engine to the outer duct.

[0047] The above-mentioned air discharge grille is made of fiber-reinforced thermoplastic resin-based composite material with low material density. Compared with aluminum alloy material, the density is about 60% to 65%, which can reduce weight by 35% to 40%. The entire intermediate unit can reduce weight by about 4.4kg to 5kg, thereby improving the efficiency of the engine.

[0048] The composite material air vent grille also has good wear resistance, which makes the air vent grille easy to assemble and has good durability.

[0049] The composite material air discharge grille is hard and elastic at the same time, and can play a buffering role when the intermediate unit body initiates micro-movement or vibration, thereby reducing the mutual wear between metal parts.

[0050] In addition, the composite structure air vent grille is easy to repair and replace. When the adhesive joints are damaged, they can be repaired by welding, or they can be replaced as a whole depending on the usage conditions.

[0051] The method for preparing the air release grille is an injection molding method, which includes the following steps.

[0052] First, step S1 is performed to manufacture a hollow split mold of the same shape as the engine exhaust grille, and the hollow mold is split along the circumference of the engine. Preferably, in step S1, the hollow split mold is provided with fixing parts at both ends, and the fixing parts are used to fix the hollow split mold, and the fixing process lasts throughout the entire injection and curing process.

[0053] In step S1, a glue injection hole may be opened on any side of the hollow split mold, and a glue outlet hole may be opened on any side of the hollow split mold.

[0054] The injection hole of the hollow split mold is preferably located on the half mold on one side of the outer surface of the engine radial air discharge grille.

[0055] The number of glue injection holes can be 3, respectively located on the first wall surface close to the front bolt hole, the first side surface, and the second side surface; or the number of glue injection holes can be 4, respectively located on the first wall surface close to the front bolt hole, the first side surface, the second side surface, and the third side surface.

[0056] The glue outlet holes of the hollow split mold are preferably located on the half mold on one side of the inner surface of the engine radial exhaust grille. The number of glue outlet holes can be 4, which are respectively located at the front end and rear end of the first wall surface close to the first side surface and the front end and rear end position close to the second side surface.

[0057] Then, steps S2 and S3 are performed, wherein a release agent is applied to the surface of the hollow split mold, one half of the hollow split mold is fixed, and bolt hole inserts of the first wall surface, the first side surface, and the second side surface are fixed in the fixed half mold. The bolt hole inserts are used to define the first bolt hole and the second bolt hole during the casting process.

[0058] Then, steps S4 and S5 are performed to close and fix the hollow split mold, preheat the mold to a certain temperature, and inject a composite material, preferably a fiber-reinforced thermoplastic resin-based composite material, into the hollow split mold.

[0059] The resin matrix of the fiber-reinforced thermoplastic resin-based composite material is preferably polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyaryletherketone (PAEK), polyetherimide (PEI), or polyphenylene sulfide (PPS).

[0060] In step S4, a hot press is used to preheat the mold to 180°C to 220°C, such as 190°C.

[0061] The fiber-reinforced thermoplastic resin-based composite material in a molten state is extruded into a hollow split mold using an injection molding machine. Preferably, the mold temperature during composite material injection is 180°C to 220°C, the injection temperature is 370°C to 420°C, the injection pressure is 40MPa to 80MPa, and the injection time is 1min to 10min.

[0062] Finally, step S6 is performed, the composite material is cured and formed, and the part is demoulded to obtain the part.

[0063] The reinforcing fibers of the fiber-reinforced thermoplastic resin-based composite material are preferably chopped fibers with an average length of 1 mm to 10 mm. The content of the chopped fibers in the composite material is preferably 10% to 50% (wt).

[0064] Preferably, the chopped fibers are carbon fibers or glass fibers.

[0065] The above method can realize one-time molding and preparation of a vent grille with multiple longitudinal ribs, multiple guide vanes, and multiple bolt holes. The preparation method is injection molding, specifically using a net size closed mold molding method, which can realize one-time molding with high molding precision, without the need for subsequent welding and machining, reducing the number of processes, saving time, improving production efficiency and material utilization, and reducing production costs.

[0066] The following describes the preparation method of the composite material air release grid through multiple embodiments.

[0067] Example 1

[0068] The air discharge grid is prepared by using a chopped carbon fiber reinforced polyetheretherketone (PEEK) composite material, wherein the content of the chopped carbon fiber is 10% to 50% (wt), such as 30%.

[0069] The preparation steps are as follows.

[0070] S101: A hollow mold of the same shape as the engine air vent grille is manufactured and split in half along the circumference of the engine. The hollow split mold has three injection holes, all of which are located on the half mold on one side of the outer surface of the engine radial air vent grille, and are respectively located on the first wall 10 near the front bolt hole, the first side 11, and the second side 12. The hollow split mold has four injection holes, all of which are located on the half mold on one side of the inner surface of the engine radial air vent grille, and are respectively located on the first wall near the front and rear ends of the first side and near the front and rear ends of the second side.

[0071] S102: Coat a mold release agent on the mold surface and wait until the surface is dry.

[0072] S103: placing one half of the hollow split mold on a hot press, fixing the mold with a fixing member, and fixing the bolt hole inserts on the first wall surface, the first side surface, and the second side surface in the mold.

[0073] S104: Close and fix the hollow split mold, and preheat the mold to 180°C to 220°C, such as 190°C.

[0074] S105: Injecting molten short carbon fiber reinforced polyetheretherketone composite material into a hollow split mold, the injection temperature is 370° C. to 420° C., such as 390° C.; the injection pressure is 40 MPa to 80 MPa, such as 80 MPa; the injection time is 1 min to 10 min, such as 8 min.

[0075] S106: After the injection is completed, the mold stops heating, the part is solidified and formed, and the mold is opened when the furnace cools to below 60°C, and the part is demoulded to complete the preparation.

[0076] Example 2

[0077] The air discharge grid is prepared by using a chopped carbon fiber reinforced polyetherketoneketone (PEKK) composite material, wherein the content of the chopped carbon fiber is 10% to 50% (wt), such as 20%.

[0078] In the preparation steps, S201-S204 and S206 are the same as steps S101-S104 and S106 of Example 1, but in step S205, the injection temperature is 350°C to 390°C, such as 370°C, the injection pressure is 40MPa to 80MPa, such as 70MPa; and the injection time is 1min to 10min, such as 7min.

[0079] Example 3

[0080] The venting grid is prepared by using a chopped glass fiber reinforced polyaryletherketone (PAEK) composite material, wherein the content of the chopped glass fiber is 10% to 50% (wt), such as 50%.

[0081] In the preparation steps, S301-S304 and S306 are the same as steps S101-S104 and S106 of Example 1, but in step S305, the injection temperature is 320°C to 360°C, such as 340°C, the injection pressure is 40MPa to 80MPa, such as 60MPa; and the injection time is 1min to 10min, such as 6min.

[0082] Example 4

[0083] The venting grid is prepared by using a short glass fiber reinforced polyetherimide (PEI) composite material, wherein the short glass fiber content is 10% to 50% (wt), such as 40%.

[0084] In the preparation steps, S401-S404 and S406 are the same as steps S101-S104 and S106 of Example 1, but in step S405, the injection temperature is 310°C to 350°C, such as 330°C, the injection pressure is 40MPa to 80MPa, such as 50MPa; and the injection time is 1min to 10min, such as 5min.

[0085] Example 5

[0086] The air discharge grille is made of short-cut carbon fiber reinforced polyphenylene sulfide (PPS) composite material.

[0087] In the preparation steps, S501-S504 and S506 are the same as steps S101-S104 and S106 of Example 1, but in step S505, the injection temperature is 300°C to 340°C, such as 315°C, the injection pressure is 40MPa to 80MPa, such as 40MPa; and the injection time is 1min to 10min, such as 4min.

[0088] Example 6

[0089] In the preparation steps, S602-S606 are the same as steps S102-S106 of Example 1, but in step S601, the number of injection holes of the hollow split mold is 4, which are respectively located on the first wall 10 near the front end bolt hole, the first side 11, the second side 12 and the third side 13.

[0090] It should be noted that the above content uses words such as "first" and "second" to limit components, which is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0091] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0092] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. The air release grille is characterized by: Circumferentially mounted on the outside of the receiver, including: The first wall surface is a curved surface structure with an arc; A first side surface, a second side surface, and a third side surface are respectively arranged on the circumferential left side, the circumferential right side, and the axial rear side of the first wall surface; A plurality of longitudinal ribs are staggeredly arranged on the first wall surface to define a gap area; and A plurality of guide vanes are located in the gap area.

2. The air release grille according to claim 1, characterized in that: A plurality of guide vanes are arranged in parallel and perpendicular to the longitudinal ribs, and form an acute angle with the first wall surface.

3. The air release grille according to claim 2, characterized in that: The acute angle defined by the guide vane and the first wall surface connected thereto is in the range of 30 to 60 degrees.

4. The air release grille according to claim 2, characterized in that: The guide vane is a curved surface structure with an arc.

5. The air release grille according to claim 1, characterized in that: The first wall surface, the first side surface and the second side surface are equal thickness structures, and the first side surface and the second side surface have the same thickness.

6. The air release grille according to claim 1, characterized in that: The first wall surface is provided with a first bolt hole, and the first side surface and the second side surface are provided with a second bolt hole.

7. The air release grille according to claim 6, characterized in that: The first wall surface is a non-uniform thickness structure, including a main body portion and a thick wall portion, and the thick wall portion is located around the first bolt hole.

8. The air release grille according to claim 7, characterized in that: The thickness of the main body portion is 4 mm to 8 mm, and the thickness of the thick-walled portion is 7 mm to 11 mm.

9. The air release grille according to claim 1, characterized in that: The air release grid is a fiber-reinforced thermoplastic resin-based composite material.

10. A method for preparing a venting grid, characterized in that: The method for preparing the air release grid according to any one of claims 1 to 9 comprises the following steps: S1. A hollow split mold of the same shape is manufactured according to the shape of the engine exhaust grille, wherein the hollow mold is split along the circumferential direction of the engine; S2. Coating a release agent on the surface of the hollow split mold; S3. Fixing half of the hollow split mold, fixing the first wall, the first side and the bolt hole inserts of the second side of the vent grille in the fixed half mold; S4. The hollow split mold is closed and fixed, and the mold is preheated to a certain temperature; S5. Injecting the composite material into the hollow split mold; S6. The composite material is solidified and molded, and the parts are demoulded to obtain the parts.

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