Aero-engine exhaust pipe

Abstract

An aero-engine exhaust pipe comprises exhaust manifolds and an exhaust main pipe, the multiple exhaust manifolds are detachably connected to one exhaust main pipe, and the exhaust manifolds are used for being connected with an exhaust passage of an aero-engine cylinder head. The section of the exhaust passage is rectangular, the end, connected with the exhaust passage, of the exhaust manifold is provided with a variable-section pipe gradually changing from rectangle to circle, the end face shape of the variable-section pipe is the same as the section shape of the exhaust passage, and the end, connected with the exhaust manifold, of the exhaust manifold is a circular pipe. Due to the fact that the exhaust manifold is provided with the variable cross-section pipe gradually changing from the rectangle to the circle, and the end face shape of the variable cross-section pipe is the same as the cross-section shape of the exhaust passage, waste gas can enter the exhaust manifold from the exhaust passage without hindrance, and the exhaust efficiency of the aero-engine can be improved. In addition, according to the connecting structure of the exhaust manifold and the exhaust main pipe of the exhaust pipe, the exhaust manifold and the exhaust main pipe can be detachably connected under the condition that waste gas is prevented from leaking.

Description

Technical Field

[0001] The utility model relates to the technical field of aviation engines, in particular to an aviation engine exhaust pipe. Background Art

[0002] A horizontally opposed aircraft engine primarily consists of a casing, crankshaft, connecting rod, piston, cylinder head, and exhaust pipe. The cross-sectional shape of the cylinder head's intake and exhaust ducts significantly impacts engine performance. Tests have shown that rectangular intake and exhaust ducts improve engine intake and exhaust efficiency. However, the existing exhaust pipes connected to these ducts are circular in cross-section. This creates turbulence and air resistance when exhaust flows from the cylinder head's exhaust ducts into the exhaust pipes, impacting exhaust efficiency.

[0003] Horizontally opposed aircraft engines typically feature multiple cylinders. To facilitate centralized exhaust, existing exhaust pipes consist of multiple exhaust manifolds and two exhaust headers. The exhaust manifolds are connected to the cylinder heads, with multiple exhaust manifolds on the same side connected to a single exhaust header. Both the exhaust manifolds and headers are round tubes because they can be bent into complex shapes, while rectangular tubes cannot. This necessitates improvements to the exhaust pipe to improve exhaust efficiency. Utility Model Content

[0004] In order to overcome the deficiencies in the background technology, the utility model discloses an aircraft engine exhaust pipe, the purpose of which is to allow exhaust gas to enter the exhaust manifold from the exhaust duct without hindrance, thereby improving the exhaust efficiency of the aircraft engine.

[0005] Specifically, the present invention adopts the following technical solutions:

[0006] An aircraft engine exhaust pipe includes an exhaust manifold and an exhaust main pipe. Multiple exhaust manifolds are detachably connected to the exhaust main pipe. The exhaust manifold is used to connect to the exhaust duct of the aircraft engine cylinder head. The cross-section of the exhaust duct is rectangular. The end of the exhaust manifold connected to the exhaust duct has a variable cross-section pipe that gradually changes from rectangular to circular. The end face shape of the variable cross-section pipe is the same as the cross-section shape of the exhaust duct. The end of the exhaust manifold connected to the exhaust main pipe is a circular pipe.

[0007] To further improve the technical solution, a connecting plate is fixed at the end of the variable-section channel, two connecting holes are provided on the connecting plate, and the variable-section pipe is located in the middle of the two connecting holes.

[0008] To further improve the technical solution, an annular ring is coaxially welded on the outer wall of the circular tube, and hooks are welded on the exhaust manifold and the circular tube; the exhaust manifold has a plurality of docking tubes corresponding to the circular tubes. When the exhaust manifold is connected to the exhaust manifold, the end faces of the docking tubes are pressed against the annular ring, and tension springs are installed between the hooks.

[0009] To further improve the technical solution, an asbestos gasket is installed between the annular ring and the end face of the butt pipe.

[0010] To further improve the technical solution, the exhaust manifold has multiple butt joints corresponding to the circular tubes, annular rings are coaxially welded on the outer walls of the butt joints, and hooks are welded on the exhaust manifold and the circular tubes; when the exhaust manifold is connected to the exhaust manifold, the end face of the circular tube is pressed against the annular ring, and a tension spring is installed between the hooks.

[0011] To further improve the technical solution, an asbestos gasket is installed between the annular ring and the end face of the circular tube.

[0012] After implementing the above technical solution, compared with the background technology, the beneficial effects produced by the present invention are:

[0013] 1. Since the exhaust manifold has a variable cross-section tube that gradually changes from rectangular to circular, and the end face shape of the variable cross-section tube is the same as the cross-sectional shape of the exhaust duct, the exhaust gas can enter the exhaust manifold from the exhaust duct without hindrance, which is beneficial to improving the exhaust efficiency of the aircraft engine.

[0014] 2. The connection structure between the exhaust manifold and the exhaust main pipe can realize the detachable connection between the exhaust manifold and the exhaust main pipe while preventing the exhaust gas from leaking out. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Attachment Figure 1 Shown is a schematic structural diagram of a horizontally opposed two-cylinder aircraft engine.

[0016] Attachment Figure 2 Shown is a schematic diagram of the three-dimensional structure of the exhaust manifold in Example 1.

[0017] Attachment Figure 3 Shown is a top view of the exhaust manifold.

[0018] Attachment Figure 4 Shown is a bottom view of the exhaust manifold.

[0019] Attachment Figure 5 Shown is a schematic structural diagram of the exhaust pipe in Example 2.

[0020] Attachment Figure 6 Shown is the attached Figure 5 Schematic diagram of the structure connecting the exhaust manifold and the exhaust main pipe.

[0021] Attachment Figure 7 The diagram shows the structure of the connection between the exhaust manifold and the exhaust main pipe in Example 3.

[0022] In the attached figure: 1. Exhaust manifold; 11. Variable-section pipe; 12. Circular pipe; 13. Connecting plate; 2. Exhaust main pipe; 21. Butt-jointed pipe; 3. Annular ring; 4. Hook; 5. Tension spring; 6. Asbestos gasket; 7. Cylinder head. DETAILED DESCRIPTION

[0023] The following describes preferred embodiments of the present invention with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely intended to illustrate the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. It should be noted that, in the description of the present invention, terms such as "front," "rear," "up," "down," "left," "right," "vertical," "horizontal," "inside," and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the device or component must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. It should also be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can mean fixed, detachable, or integral; mechanical or electrical; direct, indirect through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0024] Example 1:

[0025] Refer to the attached Figure 1 A horizontally opposed two-cylinder aircraft engine has two exhaust manifolds 1, which are respectively connected to the exhaust ducts of two cylinder heads 7 for discharging combustion exhaust gas. In order to improve the exhaust efficiency of the aircraft engine, the cross-section of the exhaust duct is roughly rectangular.

[0026] Refer to the attached Figure 2 , Attachment Figure 3 and attached Figure 4 , attached Figure 2 The diagram shows the three-dimensional structure of the exhaust manifold 1. Figure 3 Shown is a top view of the exhaust manifold 1, Figure 4 Shown is a bottom view of the exhaust manifold 1. Figure 2 , Attachment Figure 3 and attached Figure 4As can be seen, the end of the exhaust manifold 1 connected to the exhaust duct has a variable cross-section tube 11 that gradually changes from rectangular to circular. The end face shape of the variable cross-section tube 11 is the same as the cross-section shape of the exhaust duct. The other end of the exhaust manifold 1 is a circular tube 12. Because the exhaust manifold 1 has a variable cross-section tube 11 that gradually changes from rectangular to circular, and the end face shape of the variable cross-section tube 11 is the same as the cross-section shape of the exhaust duct, exhaust gas can enter the exhaust manifold 1 from the exhaust duct unimpeded, which is beneficial to improving the exhaust efficiency of the aircraft engine.

[0027] Exhaust manifold 1 is formed by pressing a single round tube. One end of the tube is formed by a die into a variable-section tube 11 that gradually transitions from rectangular to circular. The other end remains unpressed, forming a circular tube 12. Therefore, the cross-sectional area of ​​exhaust manifold 1 gradually increases from variable-section tube 11 toward circular tube 12, further reducing exhaust resistance.

[0028] A connecting plate 13 is fixed to the end of the variable-section duct. It features a rectangular hole and two connecting holes. The rectangular hole is located midway between the two connecting holes and has a cross-sectional shape slightly larger than that of the exhaust duct. The variable-section pipe 11 is inserted into the rectangular hole and welded to it. The function of the connecting plate 13 is to bolt the exhaust manifold 1 to the cylinder head 7 and ensure smooth communication between the exhaust duct and the variable-section pipe 11.

[0029] Typically, the exhaust manifold 1 needs to be connected to the exhaust header 2 to facilitate overall engine layout and unified exhaust. However, for some applications, a two-cylinder or four-cylinder aircraft engine can omit the exhaust header 2 and exhaust directly through the exhaust manifold 1.

[0030] Example 2:

[0031] Refer to the attached Figure 5 and attached Figure 6 In this embodiment, multiple exhaust manifolds 1 are detachably connected to a single exhaust manifold 2. An annular ring 3 is coaxially welded to the outer wall of a circular tube 12, and hooks 4 are welded to both the exhaust manifold 2 and the circular tube 12. The exhaust manifold 2 has multiple butt joints 21 corresponding to the circular tubes 12. When the exhaust manifolds 1 and 2 are connected, the end faces of the butt joints 21 press against the annular ring 3, and tension springs 5 ​​are installed between the hooks 4.

[0032] Due to space constraints, the exhaust manifold 1 and exhaust manifold 2 need to be bent into complex spatial shapes. They must be manufactured separately. Multiple docking tubes 21 are installed on the exhaust manifold 2. During assembly, the exhaust manifold 1 is inserted into the docking tubes 21. Due to the gaps between the connections, exhaust gas can leak from the connection. An annular ring 3, hook 4, and tension spring 5 are provided. When the circular tube 12 is connected to the docking tube 21, the tension of the tension spring 5 presses the end face of the docking tube 21 against the annular ring 3 to form a sealing surface, preventing exhaust gas leakage.

[0033] In order to improve the sealing performance, an asbestos gasket 6 is installed between the annular ring 3 and the end surface of the butt pipe 21 .

[0034] Example 3:

[0035] Refer to the attached Figure 7 In this embodiment, an annular ring 3 is coaxially welded to the outer wall of the butt joint 21, and hooks 4 are welded to the exhaust manifold 2 and the circular tube 12. When the exhaust manifold 1 and the exhaust manifold 2 are connected, the end face of the circular tube 12 presses against the annular ring 3, and a tension spring 5 is installed between the hooks 4. To improve sealing, an asbestos gasket 6 is installed between the annular ring 3 and the end face of the circular tube 12.

[0036] Compared with Example 2, this embodiment can also prevent the exhaust gas from leaking out.

[0037] Parts not described in detail are prior art. Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An aircraft engine exhaust pipe, comprising an exhaust manifold and an exhaust header, wherein multiple exhaust manifolds are detachably connected to the exhaust header, and the exhaust manifold is used to connect to the exhaust duct of the aircraft engine cylinder head, and wherein: The cross-sectional shape of the exhaust duct is rectangular. The end where the exhaust manifold is connected to the exhaust duct has a variable-section tube that gradually changes from rectangular to circular. The end face shape of the variable-section tube is the same as the cross-sectional shape of the exhaust duct. The end where the exhaust manifold is connected to the exhaust main pipe is a circular tube.

2. The aircraft engine exhaust pipe according to claim 1, wherein: A connecting plate is fixed at the end of the variable-section channel, two connecting holes are provided on the connecting plate, and the variable-section pipe is located in the middle of the two connecting holes.

3. The aircraft engine exhaust pipe according to claim 1, wherein: An annular ring is coaxially welded on the outer wall of the circular tube, and hooks are welded on the exhaust main pipe and the circular tube; the exhaust main pipe has a plurality of butt joints corresponding to the circular tubes. When the exhaust manifold is connected to the exhaust main pipe, the end faces of the butt joints are pressed against the annular ring, and tension springs are installed between the hooks.

4. The aircraft engine exhaust pipe according to claim 3, characterized in that: An asbestos gasket is installed between the annular ring and the end face of the butt pipe.

5. The aircraft engine exhaust pipe according to claim 1, characterized in that: The exhaust manifold has multiple butt joints corresponding to the circular tubes, annular rings are coaxially welded on the outer walls of the butt joints, and hooks are welded on the exhaust manifold and the circular tubes; when the exhaust manifold is connected to the exhaust manifold, the end face of the circular tube is pressed against the annular ring, and a tension spring is installed between the hooks.

6. The aircraft engine exhaust pipe according to claim 5, characterized in that: An asbestos gasket is installed between the annular ring and the end face of the circular tube.

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