A four-point mounting structure for narrow-space aircraft engines

Abstract

This invention discloses a four-point mounting structure for a narrow-space aircraft engine. It includes an outer main mounting section (1) and an inner main mounting section (2) mounted on the forward fuselage frame, a transverse bracing assembly mounted on the rear fuselage frame (39), and a diagonal bracing assembly mounted on the rear fuselage central bulkhead (40). The rear fuselage frame (39) and the rear fuselage central bulkhead (40) are on the same cross-section. The outer and inner main mounting sections (1) are respectively connected to the engine's own outer and inner main mounting section connectors, and the transverse and diagonal bracing assemblies are respectively connected to the engine's own upper suspension connector (28) and diagonal suspension connector. This invention can reduce the stress level of engine mounting parts and effectively improve pilot comfort.

Description

Technical Field

[0001] This invention relates to the field of aircraft engine mounting structure technology, and in particular to a four-point mounting structure for a narrow-space aircraft engine. Background Technology

[0002] As one of the power sources of an aircraft, the installation and fixing method of the engine is a very important part of the aircraft structural design. Due to differences in the engine's mounting location, reserved space, and engine type, its installation method also varies. Engines are typically installed using a three-point mounting method. However, this method has the following disadvantages: the vibration transmitted from the engine to the fuselage structure is relatively large, the stress on the engine mounting parts is high, and it affects the pilot's comfort. Summary of the Invention

[0003] The purpose of this invention is to provide a four-point mounting structure for aircraft engines in narrow spaces. This invention can reduce the stress level of engine mounting components and effectively improve pilot comfort.

[0004] Technical Solution. A four-point mounting structure for a narrow-space aircraft engine includes an outer main mounting section and an inner main mounting section mounted on the forward fuselage frame, a transverse tie assembly mounted on the aft fuselage frame, and a diagonal tie assembly mounted on the aft fuselage center bulkhead; the aft fuselage frame and the aft fuselage center bulkhead are in the same cross-section; the outer and inner main mounting sections are respectively connected to the engine's own outer and inner main mounting section joints, and the transverse and diagonal tie assemblies are respectively connected to the engine's own upper suspension joint and diagonal suspension joint.

[0005] In the aforementioned four-point mounting structure of a narrow-space aircraft engine, the outer main mounting section includes a left thrust pin, a hinge clamp A, and an outer main mounting section support. One end of the left thrust pin with a fork lug structure A is connected to the outer main mounting section connector on the engine via a left bolt, and the other end is fixed to the outer main mounting section support via an annular boss A. One end of the hinge clamp A with a lug is connected to the outer main mounting section support via a pin A and can rotate around the pin A, while the other end is locked to the slot of the outer main mounting section support via a hinge bolt. The hinge bolt is rotatably connected to the slot of the outer main mounting section support via a pin B, and the outer main mounting section support is fixed to the forward fuselage frame.

[0006] In the aforementioned four-point mounting structure of a narrow-space aircraft engine, a bushing is added at the mating position between the fork lug structure of the left thrust pin and the left bolt.

[0007] In the aforementioned four-point mounting structure of the narrow-space aircraft engine, the left thrust pin is an integrated design, and the bottom of the cylinder connected to the outer main mounting section support is provided with a lightening recess. This not only reduces machining errors and facilitates disassembly and assembly, but also meets the requirements of lightweight design.

[0008] In the aforementioned four-point mounting structure of a narrow-space aircraft engine, the inner main mounting section includes a right thrust pin, an eccentric bushing, and an inner main mounting section support. One end of the right thrust pin, which has a fork lug structure, is connected to the inner main mounting section connector on the engine via a right bolt, and the other end is fitted with an eccentric bushing. The eccentric bushing is connected to the inner main mounting section support via an annular boss B and locked by a hinge clamp B. The right thrust pin can move axially and rotate around the axis within the eccentric bushing. The inner main mounting section support is fixed to the forward fuselage frame.

[0009] In the aforementioned four-point mounting structure for a narrow-space aircraft engine, the lateral tie rod assembly includes a lateral tie rod. One end of the lateral tie rod with a lifting ring is connected to the upper hanger connector on the engine, and the other end with a fork lug structure B is connected to the lateral tie rod support via a lateral tie rod bolt. The lateral tie rod support is fixed to the rear fuselage frame, and both the lifting ring and the fork lug structure B of the lateral tie rod can move axially along the sleeve of the lateral tie rod. Ball bearings A are installed at the lug connections at both ends of the lateral tie rod.

[0010] In the aforementioned four-point mounting structure for narrow-space aircraft engines, the reinforcing ribs around the tie rod support holes are all chamfered.

[0011] In the aforementioned four-point mounting structure for a narrow-space aircraft engine, the inclined tie assembly includes an inclined tie rod. One end of the inclined tie rod is connected to an inclined hanger connector on the engine, and the other end is fixed to a flat plate support by bolts on the inclined tie rod. Ball bearings B are installed in the lug holes of both lugs. The side wall of the flat plate support is fixed to the aircraft frame by side connecting bolts, and the base plate is connected to the rear fuselage mid-section plate by bottom connecting bolts.

[0012] Beneficial Effects: Compared to the three-point installation method, this invention employs a four-point installation, resulting in lower load on the mounting joints and less vibration transmitted from the engine to the fuselage structure. This not only reduces the stress level of engine mounting components but also effectively improves driver comfort. The thrust pin of the outer main mounting section adopts an integrated design, directly fixed to the support by designing an annular boss at the cylindrical end of the thrust pin, reducing the number of parts and improving assembly efficiency. Unlike the thrust pin of the outer main mounting section, the thrust pin of the inner main mounting section does not directly contact the support of the outer main mounting section but is fixed to the main mounting section support through an external bushing. The thrust pin of the inner main mounting section can move along the axis of the eccentric bushing and rotate around the axis, thereby eliminating thermal stress generated in the wingspan direction. Because the engine main mounting section is designed with a hinge bolt and clamp combination, and the rear and oblique suspensions use a tie rod and support combination, assembly is simple and can be quickly disassembled. In addition, the main mounting section support is designed with a lightening recess, and the tie rod is directly connected to the flat plate support on the middle partition by bolts, thus requiring less assembly space and lighter weight.

[0013] In summary, the four-point mounting structure for an aircraft engine provided by this invention facilitates assembly and disassembly, reduces the load and vibration transmitted from the engine to the fuselage structure, and lowers the overall stress level of the mounting structure. This effectively improves pilot comfort while ensuring aircraft safety. Furthermore, the main mounting section support features a light-reducing recess, and the tie rod support uses a flat plate design, requiring less assembly space and resulting in a lighter overall weight for the engine mounting structure. The thrust pin of the outer main mounting section adopts an integrated design, reducing machining errors and improving assembly efficiency. In addition, both the main and auxiliary mounting section supports are chamfered to effectively prevent stress concentration, thereby extending the service life of the components. Attached Figure Description

[0014] Figure 1 Assembly diagram for an aircraft engine using a four-point mounting configuration;

[0015] Figure 2 Schematic diagram of the external main installation section;

[0016] Figure 3 Sectional view of the outer main installation section

[0017] Figure 4 Schematic diagram of the inner main installation section;

[0018] Figure 5 This is a schematic diagram of the tie rod structure;

[0019] Figure 6 This is a schematic diagram of a tie rod structure. Detailed Implementation

[0020] Example 1. A four-point mounting structure for a narrow-space aircraft engine, see [reference]. Figures 1-6 It includes an outer main mounting section 1 and an inner main mounting section 2 installed on the front fuselage frame, a transverse tie assembly installed on the rear fuselage frame 39, and a diagonal tie assembly installed on the rear fuselage center partition 40; the rear fuselage frame 39 and the rear fuselage center partition 40 are in the same cross section; the outer and inner main mounting sections 1 are respectively connected to the outer and inner main mounting section joints on the engine, and the transverse and diagonal tie assemblies are respectively connected to the upper suspension joint 28 and the diagonal suspension joint on the engine.

[0021] The aforementioned outer main mounting section 1 includes a left thrust pin 7, a hinge clamp A8, and an outer main mounting section support 10. One end of the left thrust pin 7 with a fork lug structure A is connected to the outer main mounting section connector on the engine via a left bolt 15, and the other end is fixed to the outer main mounting section support 10 via an annular boss A41. The annular boss A41 is used to restrict the axial movement of the left thrust pin 7. One end of the hinge clamp A8 with a lug is connected to the outer main mounting section support 10 via a pin A9 and can rotate around the pin A9. The other end is locked to the slot of the outer main mounting section support 10 via a hinge bolt 12. The hinge bolt 12 is rotatably connected to the slot of the outer main mounting section support 10 via a pin B11. The outer main mounting section support 10 is fixed to the front fuselage frame.

[0022] A bushing 17 is installed at the mating position of the fork lug structure of the aforementioned left thrust pin 7 and the left bolt 15.

[0023] The aforementioned left thrust pin 7 is an integrated design, and the bottom of the cylinder connected to the outer main mounting section support 10 is provided with a lightening recess 42, which not only reduces machining errors and facilitates disassembly and assembly, but also meets the requirements of lightweight design.

[0024] The aforementioned inner main mounting section 2 includes a right thrust pin 18, an eccentric bushing 19, and an inner main mounting section support 20. One end of the right thrust pin 18 with a fork structure is connected to the inner main mounting section connector on the engine via a right bolt, and the other end is fitted with the eccentric bushing 19. The eccentric bushing 19 is connected to the inner main mounting section support 20 via an annular boss B43 and locked by a hinge clamp B44. The right thrust pin 18 can move axially and rotate around the shaft within the eccentric bushing 19. The inner main mounting section support 20 is fixed on the front fuselage frame.

[0025] The aforementioned tie rod assembly includes a tie rod. One end of the tie rod, equipped with a lifting ring 21, is connected to the upper suspension connector 28 on the engine. The other end, equipped with a fork lug structure B27, is connected to the tie rod support 25 via a tie rod bolt 23. The tie rod support 25 is fixed to the rear fuselage frame 39. Both the lifting ring 21 and the fork lug structure B27 of the tie rod can move axially along the sleeve 22 of the tie rod. Ball bearings A26 are installed at the lug connections at both ends of the tie rod.

[0026] The reinforcing ribs around the 25-hole edge of the aforementioned tie rod support are all chamfered.

[0027] The aforementioned inclined tie rod assembly includes an inclined tie rod 29. One end of the inclined tie rod 29 is connected to the inclined hanger joint on the engine, and the other end is fixed to the flat plate support 34 by the inclined tie rod bolt 33. Ball bearings B32 are installed in the lug holes of both lugs. The side wall of the flat plate support 34 is fixed to the aircraft frame by the side connecting bolts 30, and the bottom plate is connected to the rear fuselage central bulkhead 40 by the bottom connecting bolts 35.

[0028] External main installation section structure such as Figure 2 and 3 As shown, the internal main mounting section structure is as follows: Figure 4 As shown, the tie rod structure is as follows: Figure 5 As shown, the diagonal tie rod structure is as follows Figure 6 As shown. Since the installation methods of the left and right engines are exactly the same, only the installation positions differ, so only the installation and disassembly process of the left engine will be described. After confirming that the engine is securely fixed on the engine mounting vehicle, the engine mounting vehicle is slowly pushed under the rear fuselage of the aircraft, and the engine is raised to the appropriate position. First, connect one end of the left thrust pin 7 with the fork lug structure to the main mounting joint connector on the engine, and the other end is fixed to the main mounting joint support 10 by the annular boss. The left thrust pin adopts an integrated design, and the bottom of the cylinder connected to the support is designed with a lightening recess, which meets the requirements of lightweight design while reducing machining errors and facilitating disassembly and assembly. One side of the hinge clamp 8 with the lug is connected to the main mounting joint support 10 by the pin A9 and can rotate around the pin A9, while the other side is locked to the bottom of the slot of the support 10 by the hinge bolt 12, the washer 13 and the nut 14. The hinge bolt 12 is connected to the support 10 by the pin 11, and the support 10 is fixed to the fuselage frame by 4 bolts. To reduce friction between the left bolt 15 and the lugs of the thrust pin 7, bushings 17 are installed in both lug holes of the thrust pin 7, and the nut is connected to the thrust pin 7 via a washer 16. The installation methods of the left engine inner main mounting section and the outer main mounting section are basically the same. The main difference is that the thrust pin 18 of the inner main mounting section does not directly contact the inner main mounting section support 20, but is connected to the support 20 through an eccentric bushing 19 with an annular boss attached to the outside of the thrust pin 18. The thrust pin 18 can move and rotate axially within the eccentric bushing 19, thereby eliminating the thermal expansion phenomenon of the engine in the lateral direction.

[0029] One end of the tie rod with the lifting ring 21 is connected to the upper suspension connector 28 on the engine, while the other end with the fork lug structure 27 is connected to the tie rod support 25 via tie rod bolts 23. The tie rod support 25 is fixed to the rear fuselage frame 39 by three 8mm bolts 24. To reduce stress levels and extend service life, the reinforcing ribs around the holes of the tie rod support 25 are chamfered. The lifting ring 21 and the fork lug structure 27 can move along the axis of the sleeve 22, thereby changing the length of the tie rod and increasing the applicability of the structure. Ball bearings 26 are installed at the lug connections at both ends of the tie rod to compensate for engine installation errors. One lug of the diagonal tie rod 29 is connected to the diagonal suspension connector on the engine, while the other lug is fixed to the flat support 34 via bolts 33, nuts 36, bushings 31, perforated pins 37, and washers 38. Both sides of the lugs are fitted with ball bearings 32, which can compensate for installation errors and adjust the angle θ between the tie rod axis and the aircraft's horizontal reference line. To increase the ball bearing's wear resistance, low-temperature stability, and service life during rotation, a suitable amount of low-temperature grease is applied to the rotating parts of the ball bearing. The sidewalls of the flat plate support 34 are fixed to the aircraft frame with four bolts 30, and the base plate is connected to the rear fuselage central bulkhead with bolts 35. Compared to other support types, the flat plate support requires a smaller distance d between the two engines, is lighter, and is easier to install. When the engine needs to be removed, simply pull out the pins of the inner and outer main mounting sections, remove the perforated pins in the tie rod and diagonal tie rod structures, and loosen the corresponding fasteners.

Claims

1. A four-point mounting structure for a narrow-space aircraft engine, characterized in that, The main mounting section includes an outer main mounting section (1) and an inner main mounting section (2) mounted on the front fuselage frame, a transverse tie assembly mounted on the rear fuselage frame (39), and a diagonal tie assembly mounted on the rear fuselage center partition (40). The rear fuselage frame (39) and the rear fuselage center partition (40) are in the same cross section. The outer and inner main mounting sections are respectively connected to the outer and inner main mounting section joints on the engine. The transverse and diagonal tie assemblies are respectively connected to the upper suspension joint (28) and the diagonal suspension joint on the engine. The outer main mounting section (1) includes a left thrust pin (7), a hinge clamp A (8), and an outer main mounting section support (10). The left thrust pin (7) has a fork. One end of the ear structure A is connected to the external main mounting joint connector on the engine via a left bolt (15), and the other end is fixed to the external main mounting joint support (10) via an annular boss A (41); the end of the hinge clamp A (8) with the ear plate is connected to the external main mounting joint support (10) via a pin A (9) and can rotate around the pin A (9), and the other end is locked to the slot of the external main mounting joint support (10) via a hinge bolt (12); the hinge bolt (12) is rotatably connected to the slot of the external main mounting joint support (10) via a pin B (11), and the external main mounting joint support (10) is fixed to the front fuselage frame; The inner main mounting section (2) includes a right thrust pin (18), an eccentric bushing (19), and an inner main mounting section support (20). One end of the right thrust pin (18) with a fork structure is connected to the inner main mounting section connector on the engine via a right bolt, and the other end is fitted with the eccentric bushing (19). The eccentric bushing (19) is connected to the inner main mounting section support (20) via an annular boss B (43) and locked by a hinge clamp B (44). The right thrust pin (18) can move axially and rotate around the shaft within the eccentric bushing (19). The inner main mounting section support (20) is fixed on the front fuselage frame. The lateral tie rod assembly includes a tie rod with a lifting ring (21) at one end connected to the upper hanger joint (28) on the engine, and a tie rod with a fork structure B (27) at the other end connected to the tie rod support (25) via a tie rod bolt (23). The tie rod support (25) is fixed on the rear fuselage frame (39). Both the lifting ring (21) and the fork structure B (27) of the tie rod can move axially along the sleeve (22) of the tie rod. Ball bearings A (26) are installed at the lug connections at both ends of the tie rod. The inclined tie rod assembly includes an inclined tie rod (29). One end of the inclined tie rod (29) is connected to the inclined hanger joint on the engine, and the other end is fixed to the flat support (34) by the inclined tie rod bolt (33). Ball bearings B (32) are installed in the ear holes of both ends. The base plate is connected to the rear fuselage partition plate (40) by the bottom connecting bolt (35).

2. The four-point mounting structure for a narrow-space aircraft engine according to claim 1, characterized in that, A bushing (17) is installed at the mating position of the fork lug structure of the left thrust pin (7) and the left bolt (15).

3. The four-point mounting structure for a narrow-space aircraft engine according to claim 1, characterized in that, The left thrust pin (7) is an integrated design, and the bottom of the cylinder connected to the outer main mounting section support (10) is provided with a lightening recess (42), which not only reduces processing errors and facilitates disassembly and assembly, but also meets the requirements of lightweight design.

4. The four-point mounting structure for a narrow-space aircraft engine according to claim 1, characterized in that, All reinforcing ribs around the holes of the tie rod support (25) are chamfered.

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