Fuel manifold and aero-engine

Abstract

The invention discloses a fuel header pipe and an aero-engine. The fuel header pipe comprises a first branch pipe, a second branch pipe and an assembly connector. The assembly joints are used for connecting adjacent pipe bodies at preset circumferential positions; the first branch pipe sequentially comprises a first pipe section, a second pipe section and a third pipe section; a preset angle is formed between the first pipe section and the second pipe section, the first pipe section and the second pipe section are connected to the three-way connector at the preset angle, the third pipe section is constructed to extend in the preset direction to be matched with the mounting position of the fuel nozzle, the second branch pipe is structurally matched with the first branch pipe, and the length of the third pipe section of the second branch pipe is larger than that of the third pipe section of the first branch pipe; the second end of the first branch pipe and the second end of the second branch pipe are each provided with a connecting structure used for being connected with a fuel nozzle, each connecting structure comprises a sealing head and a jacket nut arranged on the sealing head in a sleeving mode, and each sealing head is provided with a limiting structure for axial limiting and an elastic sealing structure. And a sealing structure matched with the elastic sealing structure is arranged at an oil inlet of the fuel nozzle.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft engines, and in particular, to a fuel manifold. In addition, the present invention also relates to an aircraft engine comprising the fuel manifold. Background Art

[0002] The fuel manifold of an aircraft engine is the fuel supply pipeline for the fuel nozzles in the combustion chamber, and is generally located in the head area of ​​the combustion chamber. As the engine structure becomes more and more compact and the number of combustion chamber heads increases, the design space of the fuel manifold becomes smaller and smaller, and the design difficulty increases. The difficulty of the fuel manifold design is mainly reflected in the structural layout and interface sealing design.

[0003] The existing fuel main pipe design generally adopts polytetrafluoroethylene hose design to solve the problem of safe and reliable interface sealing, such as Figure 1 As shown. The branch pipe and the three-way joint are made of stainless steel, and the three-way joints are connected by polytetrafluoroethylene hoses. The flexibility of the polytetrafluoroethylene hose improves the assembly of the main pipe, thereby ensuring the reliability of the interface sealing.

[0004] Due to the complex composition of PTFE hose, its diameter is relatively thick, which in turn requires a large space for structural layout, so it is not suitable for engines with compact structure and small space for fuel manifold design. Fuel manifolds designed with stainless steel pipes have poor assembly performance in a small space due to the high hardness of stainless steel pipes, making it difficult to ensure the sealing reliability of the interface, and usually prone to oil leakage at the interface. Summary of the invention

[0005] The invention provides a fuel main pipe and an aircraft engine, so as to solve the technical problem in the prior art that the small installation space of the fuel main pipe of a small and medium-sized engine leads to poor assembly and sealing properties of the stainless steel pipe.

[0006] A fuel main pipe, the fuel main pipe comprising a plurality of pipe bodies and a three-way joint, the adjacent pipe bodies being connected in sequence to form a closed-loop main pipe, the fuel main pipe further comprising a first branch pipe, a second branch pipe and an assembly joint; the three-way joint is used to be arranged on the pipe body and to connect the first end of the first branch pipe or the first end of the second branch pipe or the oil inlet pipe; the assembly joint is used to connect the adjacent pipe bodies at a preset circumferential position; the first branch pipe comprises a first pipe section, a second pipe section and a third pipe section in sequence; a preset angle is constructed between the first pipe section and the second pipe section and the first pipe section is connected to the three-way joint at a preset angle to avoid interference with pipelines and / or mounting seats in the installation environment, the third pipe section is constructed to extend in a preset direction to match the circumferential installation position of the fuel nozzle, the second branch pipe comprises a first pipe section, a second pipe section and a third pipe section; a preset angle is constructed between the first pipe section and the second pipe section and the third pipe section is connected to the three-way joint at a preset angle to avoid interference with pipelines and / or mounting seats in the installation environment, the third pipe section is constructed to extend in a preset direction to match the circumferential installation position of the fuel nozzle, and the second branch pipe comprises a first pipe section, a second pipe section and a third pipe section. The structure of the tube matches the structure of the first branch pipe, and the length of the third tube section of the second branch pipe is greater than the length of the third tube section of the first branch pipe; the second ends of the first branch pipe and the second branch pipe are respectively provided with connection structures for connecting with the fuel nozzle, and the outer wall of the fuel inlet of the fuel nozzle is provided with an external thread, and the connection structure includes a sealing head respectively provided at the second end portion of the first branch pipe and the second end portion of the second branch pipe, and a sleeve nut sleeved on the sealing head and used for threading connection with the external thread of the fuel inlet of the fuel nozzle, the sealing head is provided with a limiting structure for axially limiting the sleeve nut, the end of the sealing head is provided with an elastic sealing structure, and the fuel inlet of the fuel nozzle is provided with a sealing structure for cooperating with the elastic sealing structure.

[0007] As a further improvement of the above technical solution, the limiting structure includes a first limiting protrusion arranged on the side wall of the sealing head, a first limiting groove opened on the inner wall of the outer sleeve nut, and an annular limiting member sleeved on the sealing head, the outer diameter of the first limiting protrusion is smaller than the inner diameter of the outer sleeve nut, the inner diameter of the annular limiting member is smaller than the outer diameter of the first limiting protrusion, and the outer diameter of the annular limiting member matches the radial dimension of the first limiting groove.

[0008] As a further improvement of the above technical solution, the cross-section of the annular limiting member is circular, the first limiting groove is an arc-shaped groove, and a rounded corner is set between the first limiting protrusion and the side wall of the sealing head.

[0009] As a further improvement of the above technical solution, the sealing structure includes a tapered mouth opened at the connecting end of the fuel nozzle, the inner diameter of the outer end of the tapered mouth is larger than the inner diameter of the inner end; the side wall of the sealing end of the sealing head is tapered and arranged in a spherical structure, the taper of the side wall of the sealing end matches the taper of the tapered mouth, and the depth of the tapered mouth is larger than the axial dimension of the sealing end of the sealing head.

[0010] As a further improvement of the above technical solution, the elastic sealing structure includes a sealing gasket, which matches the shape of the tapered mouth and is sleeved on the sealing end of the sealing head, or the sealing gasket is covered on the sealing end of the sealing head.

[0011] As a further improvement of the above technical solution, the inner wall of the sealing gasket is provided with a second limiting protrusion, and the side wall of the sealing head is provided with a second limiting groove for cooperating with the second limiting protrusion, or the inner wall of the sealing gasket is provided with a second limiting groove, and the side wall of the sealing head is provided with a second limiting protrusion for cooperating with the second limiting groove.

[0012] As a further improvement of the above technical solution, the outer wall of the outer sleeve nut is provided with a force-applying structure, and the force-applying structure includes a knurling and / or an external hexagonal structure.

[0013] As a further improvement of the above technical solution, the structure of the assembly joint matches the connection structure.

[0014] As a further improvement of the above technical solution, the outer end of the first pipe segment is used to connect with the three-way joint, and the outer end of the third pipe segment is provided with the connecting structure; there is an obtuse angle between the first pipe segment and the second pipe segment, and the interface corresponding to the first pipe segment on the three-way joint for connecting the first branch pipe or the second branch pipe is arranged inclined at a preset angle toward the center direction of the fuel main pipe, so that the first pipe segment is installed on the three-way joint in an inclined state and the second pipe segment is located in or tends to the axial direction.

[0015] According to another aspect of the present invention, an aircraft engine is provided, which includes the above-mentioned fuel main pipe.

[0016] The present invention has the following beneficial effects: The fuel main pipe is provided with multiple pipe bodies and connected by assembly joints. After the branch pipes on each pipe body are installed and connected, the pipe bodies are connected by assembly joints to form the fuel main pipe, which effectively reduces the difficulty of assembling the fuel main pipe and can make the structural design more compact and the space utilization more reasonable. The first branch pipe and the second branch pipe are both constructed in an approximately U-shaped structure. The first pipe section and the second pipe section avoid the pipelines that are prone to interference in the axial extension space of the fuel main pipe under the installation environment, and reserve more space for the T45 probe lead at the same axial position, so that the T45 probe lead can be wound from the outside of the branch pipe, which greatly reduces the difficulty of lead-in and improves the assembly of the engine. It extends from the third pipe section to the circumferential installation position tending to the fuel nozzle, and the third pipe section of the first branch pipe and the third pipe section of the second branch pipe are different in length. Therefore, the first branch pipe or the second branch pipe can be selected according to the matching of interference structures such as other mounting seats under the installation environment. The structure is more compact and reasonable. At the same time, the branch pipe structure extends the length of the branch pipe, effectively improves the flexibility of the branch pipe made of stainless steel, and further improves the assembly performance of the fuel main pipe; the second ends of the first branch pipe and the second branch pipe are respectively provided with connection structures for connecting with the fuel nozzle, and the connection structure includes a sealing head arranged at the second end of the branch pipe and a sleeve nut sleeved on the sealing head. The sealing head is provided with a limiting structure to limit the axial position of the sleeve nut, so that when the sleeve nut is threadedly connected with the fuel nozzle, the axial position of the sleeve nut is limited, and then when the sleeve nut is tightened, the sealing head cooperates with the sealing structure, and the elastic sealing structure and the sealing structure are closely matched to achieve sealing, the sealing effect is good, and the possibility of oil leakage is reduced. The limiting structure only limits the axial position of the sleeve nut in the locking direction, and the reverse retreat is not restricted, thereby avoiding interference with the fuel inlet of the fuel nozzle, improving the assembly performance of the fuel main pipe, and making the maintenance and parts replacement operations more convenient.

[0017] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 It is a schematic diagram of the structure of a polytetrafluoroethylene fuel main pipe of the prior art; Figure 2 It is a structural schematic diagram of a fuel main pipe of a preferred embodiment of the present invention; Figure 3 This is a schematic diagram of the assembly structure of the first branch pipe and the second branch pipe of a preferred embodiment of the present invention; Figure 4 is a schematic diagram of the connection structure of a preferred embodiment of the present invention; Figure 5 It is a schematic diagram of the assembly joint structure of a preferred embodiment of the present invention.

[0019] Legend: 10. Tube body; 11. First tube head; 20. Fuel nozzle; 201. Conical mouth; 202. External thread; 30. First branch pipe; 31. Outer sleeve nut; 311. First limiting groove; 312. Internal thread; 32. Elastic sealing structure; 33. Annular limiting member; 34. Sealing head; 341. Second limiting groove; 342. First limiting protrusion; 343. Sealing surface; 40. Three-way joint; 51. Second tube head; 52. Sealing joint; 60. Oil inlet pipe; 70. Second branch pipe. DETAILED DESCRIPTION

[0020] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0021] Figure 2 It is a structural schematic diagram of a fuel main pipe of a preferred embodiment of the present invention; Figure 3 This is a schematic diagram of the assembly structure of the first branch pipe and the second branch pipe of a preferred embodiment of the present invention; Figure 4 is a schematic diagram of the connection structure of a preferred embodiment of the present invention; Figure 5 It is a schematic diagram of the assembly joint structure of a preferred embodiment of the present invention.

[0022] like Figures 2 to 5As shown, the fuel main pipe of this embodiment includes a plurality of pipe bodies 10 and a three-way joint 40. Adjacent pipe bodies 10 are connected in sequence to form a closed-loop main pipe. The fuel main pipe also includes a first branch pipe 30, a second branch pipe 70 and an assembly joint. The three-way joint 40 is used to be arranged on the pipe body 10 and is used to connect the first end of the first branch pipe 30 or the first end of the second branch pipe 70 or the oil inlet pipe 60. The assembly joint is used to connect adjacent pipe bodies 10 at a preset circumferential position. The first branch pipe 30 includes a first pipe section, a second pipe section and a third pipe section in sequence. A preset angle is constructed between the first pipe section and the second pipe section and is connected to the three-way joint 40 at a preset angle to avoid interference with pipelines and / or mounting seats in the installation environment. The third pipe section is structured to extend in a preset direction to match the circumferential installation position of the fuel nozzle 20. The second branch pipe 70 The structure matches the structure of the first branch pipe 30, and the length of the third pipe section of the second branch pipe 70 is greater than the length of the third pipe section of the first branch pipe 30; the second ends of the first branch pipe 30 and the second branch pipe 70 are respectively provided with connecting structures for connecting with the fuel nozzle 20, and the outer wall of the oil inlet of the fuel nozzle 20 is provided with an external thread 202, and the connecting structures respectively include a sealing head 34 provided at the second end portion of the first branch pipe 30 and the second end portion of the second branch pipe 70, and a sleeve nut 31 sleeved on the sealing head 34 and threadedly connected to the external thread 202 of the oil inlet of the fuel nozzle 20, the sealing head 34 is provided with a limiting structure for axially limiting the sleeve nut 31, the end of the sealing head 34 is provided with an elastic sealing structure 32, and the oil inlet of the fuel nozzle 20 is provided with a sealing structure for cooperating with the elastic sealing structure 32.

[0023] The internal thread 312 of the outer sleeve nut 31 matches the external thread 202 of the fuel inlet of the fuel nozzle 20; the first interface and the second interface of the three-way joint 40 are respectively connected to the pipe body 10, and the third interface of the three-way joint 40 is connected to the pipe body 10, and the third interface is used to connect the first end of the first branch pipe 30 or the first end of the second branch pipe 70 or the fuel inlet pipe 60; specifically, at least one three-way joint 40 is connected to the fuel inlet pipe 60 to introduce fuel into the closed-loop main pipe and output it to the fuel nozzle 20 through each branch pipe; the first branch pipe, the second branch pipe and the pipe body are preferably connected by welding; It can be understood that the fuel main pipe is configured as a plurality of pipe bodies 10 and connected by assembly joints, so that after the branch pipes on each pipe body 10 are installed, the pipe bodies 10 are connected by assembly joints to form the fuel main pipe, which effectively reduces the difficulty of assembling the fuel main pipe and can make the structural design more compact and the space utilization more reasonable; the first branch pipe 30 and the second branch pipe 70 are both constructed in an approximately U-shaped structure, and the first pipe section and the second pipe section avoid the pipelines that are prone to interference in the axial extension space of the fuel main pipe under the installation environment, and reserve a larger space for the T45 probe lead at the same axial position, so that the T45 probe lead can be wound from the outside of the branch pipe, which greatly reduces the difficulty of the lead and improves the assembly of the engine; and then the third pipe section extends toward the circumferential installation position of the fuel nozzle 20, and the lengths of the third pipe section of the first branch pipe 30 and the third pipe section of the second branch pipe 70 are different, so the first branch pipe 30 or the second branch pipe 70 can be selected according to the interference structure matching of other mounting seats in the installation environment, and the structure is more The invention is compact and reasonable. At the same time, the branch pipe structure extends the length of the branch pipe, effectively improves the flexibility of the branch pipe made of stainless steel, and further improves the assembly performance of the fuel main pipe. The second ends of the first branch pipe 30 and the second branch pipe 70 are respectively provided with connection structures for connecting with the fuel nozzle 20. The connection structure includes a sealing head 34 arranged at the second end of the branch pipe and a sleeve nut 31 sleeved on the sealing head 34. The sealing head 34 is provided with a limiting structure to limit the axial position of the sleeve nut 31, so that when the sleeve nut 31 is threadedly connected with the fuel nozzle 20, the axial position of the sleeve nut 31 is limited, and then when the sleeve nut 31 is tightened, the sealing head 34 cooperates with the sealing structure, and the elastic sealing structure 32 cooperates closely with the sealing structure to achieve sealing, so that the sealing effect is good and the possibility of oil leakage is reduced. The limiting structure only limits the axial position of the sleeve nut 31 in the locking direction, and the reverse retreat is not restricted, thereby avoiding interference with the oil inlet of the fuel nozzle 20, improving the assembly performance of the fuel main pipe, and making maintenance and parts replacement operations more convenient.

[0024] The main pipe includes at least two pipe bodies 10. In this embodiment, two pipe bodies are used as an example. The three-way joint 40 at the middle of one of the pipe bodies 10 is used to connect with the oil inlet pipe 60. It should be understood that the three-way joint 40 connected to the oil inlet pipe 60 and the three-way joint 40 connected to the branch pipe are respectively matched with three-way joints 40 of different specifications. In some embodiments, the outer end of the first pipe segment is used to connect to the three-way joint 40, and a connecting structure is provided at the outer end of the third pipe segment; there is an obtuse angle between the first pipe segment and the second pipe segment, and the interface of the corresponding first pipe segment on the three-way joint 40 for connecting the first branch pipe 30 or the second branch pipe 70 is arranged at a preset angle inclined toward the center direction of the fuel main pipe, so that the first pipe segment is installed on the three-way joint 40 in an inclined state and the second pipe segment is located in or tends to the axial direction, that is, the first branch pipe 30 and the second branch pipe 70 are both constructed in an approximately U-shaped structure, and the first pipe segment is connected to the three-way joint 40 and extends downward for a certain length in the center direction of the fuel main pipe, and then extends downward in the axial direction by the second pipe segment, and finally extends in the horizontal direction by the third pipe segment gradually tending to the circumferential position of the fuel nozzle, so that there is a certain space below the main pipe, which is convenient for the T45 probe lead-in, so that it can be wound around the outside of the branch pipe, reducing the difficulty of the lead-in.

[0025] In some embodiments, the limiting structure includes a first limiting protrusion 342 provided on the side wall of the sealing head 34, a first limiting groove 311 provided on the inner wall of the outer sleeve nut 31, and an annular limiting member 33 sleeved on the sealing head 34, the outer diameter of the first limiting protrusion 342 is smaller than the inner diameter of the outer sleeve nut 31, the inner diameter of the annular limiting member 33 is smaller than the outer diameter of the first limiting protrusion 342, the outer diameter of the annular limiting member 33 matches the radial dimension of the first limiting groove 311, wherein the annular limiting member 33 has a certain Flexibility, by setting an annular limit member 33 embedded in the first limit groove 311 on the inner wall of the outer sleeve nut 31, and then the annular limit member 33 cooperates with the outer wall of the sealing head 34, and abuts against the first limit protrusion 342 to achieve axial limitation. After the outer sleeve nut 31 is retreated to the outside of the sealing head 34 to the position of the branch pipe body, the elastic sealing structure 32 can be exposed to facilitate maintenance and replacement of the elastic sealing structure 32. The operation is simple, and while ensuring sealing and assembly, the overall components are few, the structure is simple, and disassembly and assembly are convenient. Furthermore, the cross-section of the annular limit member 33 is set to be circular, the first limit groove 311 is an arc groove, and a fillet is set between the first limit protrusion 342 and the side wall of the sealing head 34. The annular limit member 33 can be made of steel wire, which is convenient for embedding into the first limit groove 311 and fitting tightly, and at the same time can fit tightly with the first limit protrusion 342 to ensure the axial limiting effect. In the axial retreat movement after the outer sleeve nut 31 is separated from the fuel nozzle 20, it has less contact area with the outer wall of the sealing head 34, and the friction resistance is small, so the outer sleeve nut 31 moves more smoothly and is easy to operate.

[0026] In some embodiments, the sealing structure includes a tapered mouth 201 opened at the connecting end of the fuel nozzle 20, the inner diameter of the outer end of the tapered mouth 201 is larger than the inner diameter of the inner end; the side wall of the sealing end of the sealing head 34 is tapered and a spherical surface is provided as the sealing surface 343, the taper of the side wall of the sealing end matches the taper of the tapered mouth 201, preferably 24°, with good assembly and sealing properties; the depth of the tapered mouth 201 is greater than the axial dimension of the sealing end of the sealing head 34, ensuring sufficient mating surface; the sealing structure and the sealing head 34 are both designed to be tapered, so that the sealing end of the sealing head 34 can be better embedded in the oil inlet of the fuel nozzle 20 during docking, so that the elastic seal The structure 32 gradually sticks to the inner wall of the tapered mouth 201 and is gradually pressed to ensure the sealing performance; further, the elastic sealing structure 32 includes a sealing gasket, which matches the shape of the tapered mouth 201, and the sealing gasket is sleeved on the sealing end of the sealing head 34, and the sealing gasket sleeved on the side wall of the sealing end cooperates with the inner wall of the tapered mouth 201; in some embodiments, the sealing gasket can also be coated on the sealing end of the sealing head 34; wherein, the sealing gasket material is T2M or N6-M, and the thickness of the sealing gasket in this embodiment is 0.15mm. In other embodiments, a sealing gasket of 0.3mm or thicker is used according to the specifications of the sealing head 34, and the material is selected according to the specific situation.

[0027] Furthermore, the inner wall of the sealing gasket is provided with a second limiting protrusion, and the side wall of the sealing head 34 is provided with a second limiting groove 341 for cooperating with the second limiting protrusion. By respectively opening the second limiting protrusion and the second limiting groove 341 on the inner wall of the sealing gasket and the side wall of the sealing strip, the sealing gasket is axially limited and fixed after being sleeved on the sealing head 34, and is withdrawn along with the sealing head 34 after being unlocked by the outer sleeve nut 31 after sealing, so that parts are not easy to fall off; in other embodiments, the inner wall of the sealing gasket may also be provided with a second limiting groove 341, and the side wall of the sealing head 34 may be provided with a second limiting protrusion for cooperating with the second limiting groove 341, which have the same connecting function.

[0028] In some embodiments, the outer wall of the outer sleeve nut 31 is provided with a force-applying structure, which includes a knurling and / or an external hexagonal structure, so that it can be driven to rotate manually or with the help of a wrench.

[0029] In some embodiments, the structure of the assembly joint matches the connection structure. For example, the first tube head 11 of a tube body 10 is provided with a sealing head 34 and a sleeve nut 31, and the second tube head 51 of the other tube body 10 is provided with a sealing joint 52. The sealing joint 52 has a tapered mouth 201 and an external thread 202. The connection method and specific structure are realized with reference to the connection structure and will not be elaborated on in detail.

[0030] On the other hand, a preferred embodiment of the present invention further provides an aircraft engine, which is equipped with the above-mentioned fuel main pipe.

[0031] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "front", "rear", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A fuel main pipe, comprising a plurality of pipe bodies (10) and a three-way joint (40), wherein adjacent pipe bodies (10) are connected in sequence to form a closed-loop main pipe, characterized in that: The fuel main pipe also includes a first branch pipe (30), a second branch pipe (70) and an assembly joint; the three-way joint (40) is used to be arranged on the pipe body (10) and is used to connect the first end of the first branch pipe (30) or the first end of the second branch pipe (70) or the oil inlet pipe (60); the assembly joint is used to connect the adjacent pipe bodies (10) at a preset circumferential position; the first branch pipe (30) includes a first pipe section, a second pipe section and a third pipe section in sequence; a preset angle is constructed between the first pipe section and the second pipe section and the first pipe section is connected to the three-way joint (40) at a preset angle to avoid interference with pipelines and / or mounting seats in the installation environment; the third pipe section is structured to extend in a preset direction to match the circumferential installation position of the fuel nozzle (20); the structure of the second branch pipe (70) matches the structure of the first branch pipe (30), and the length of the third pipe section of the second branch pipe (70) is greater than The third pipe section of the first branch pipe (30) is longer than the third pipe section of the first branch pipe (30); the second ends of the first branch pipe (30) and the second branch pipe (70) are respectively provided with connection structures for connecting with the fuel nozzle (20); the outer wall of the fuel inlet of the fuel nozzle (20) is provided with an external thread (202); the connection structure comprises a sealing head (34) respectively provided at the second end portion of the first branch pipe (30) and the second end portion of the second branch pipe (70); and an outer sleeve nut (31) sleeved on the sealing head (34) and threadedly connected with the external thread (202) of the fuel inlet of the fuel nozzle (20); the sealing head (34) is provided with a limiting structure for axially limiting the outer sleeve nut (31); the end of the sealing head (34) is provided with an elastic sealing structure (32); and the fuel inlet of the fuel nozzle (20) is provided with a sealing structure for cooperating with the elastic sealing structure (32).

2. The fuel manifold according to claim 1, characterized in that: The limiting structure comprises a first limiting protrusion (342) arranged on the side wall of the sealing head (34), a first limiting groove (311) opened on the inner wall of the outer sleeve nut (31), and an annular limiting member (33) sleeved on the sealing head (34), wherein the outer diameter of the first limiting protrusion (342) is smaller than the inner diameter of the outer sleeve nut (31), the inner diameter of the annular limiting member (33) is smaller than the outer diameter of the first limiting protrusion (342), and the outer diameter of the annular limiting member (33) matches the radial dimension of the first limiting groove (311).

3. The fuel manifold according to claim 2, characterized in that: The cross section of the annular limiting member (33) is circular, the first limiting groove (311) is an arc-shaped groove, and a rounded corner is arranged between the first limiting protrusion (342) and the side wall of the sealing head (34).

4. The fuel manifold according to claim 1, characterized in that: The sealing structure comprises a tapered opening (201) opened at the connecting end of the fuel nozzle (20), the inner diameter of the outer end of the tapered opening (201) being larger than the inner diameter of the inner end; the side wall of the sealing end of the sealing head (34) is tapered and configured to have a spherical structure, the taper of the side wall of the sealing end matches the taper of the tapered opening (201), and the depth of the tapered opening (201) is larger than the axial dimension of the sealing end of the sealing head (34).

5. The fuel manifold according to claim 4, characterized in that: The elastic sealing structure (32) comprises a sealing gasket, the sealing gasket matches the shape of the tapered opening (201), the sealing gasket is sleeved on the sealing end of the sealing head (34), or the sealing gasket is covered on the sealing end of the sealing head (34).

6. The fuel manifold according to claim 5, characterized in that: The inner wall of the sealing gasket is provided with a second limiting protrusion, and the side wall of the sealing head (34) is provided with a second limiting groove (341) for cooperating with the second limiting protrusion, or the inner wall of the sealing gasket is provided with a second limiting groove (341), and the side wall of the sealing head (34) is provided with a second limiting protrusion for cooperating with the second limiting groove (341).

7. The fuel manifold according to claim 1, characterized in that: The outer wall of the outer sleeve nut (31) is provided with a force-applying structure, and the force-applying structure includes a knurling and / or an external hexagonal structure.

8. The fuel main pipe according to any one of claims 1 to 7, characterized in that: The structure of the assembly joint matches the connection structure.

9. The fuel main pipe according to any one of claims 1 to 7, characterized in that: The outer end of the first pipe segment is used to connect to the three-way joint (40), and the outer end of the third pipe segment is provided with the connection structure; there is an obtuse angle between the first pipe segment and the second pipe segment, and the interface corresponding to the first pipe segment on the three-way joint (40) used to connect the first branch pipe (30) or the second branch pipe (70) is arranged at a preset angle inclined toward the center direction of the fuel main pipe, so that the first pipe segment is installed on the three-way joint (40) in an inclined state and the second pipe segment is located in or tends to the axial direction.

10. An aircraft engine, characterized in that: A fuel main pipe according to any one of claims 1 to 9 is used.

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