A soft fuel tank fuel system with an aircraft-like shape

Abstract

The present invention provides a soft fuel tank fuel system imitating the shape of an aircraft, which includes a front fuel tank, a middle fuel tank, and a rear fuel tank. One end of the front fuel tank is correspondingly provided with a ventilation pipeline. The top ends of the front fuel tank, the middle fuel tank, and the rear fuel tank are all correspondingly provided with a nipple connection block. A fuel tank inter-pipe is correspondingly installed at the nipple connection block, and the interiors of the front fuel tank, the middle fuel tank, and the rear fuel tank are connected through the fuel tank inter-pipe; a fuel filling pipeline is correspondingly installed at the nipple connection block of the rear fuel tank; the bottoms of the front fuel tank, the middle fuel tank, and the rear fuel tank are connected through an inter-tank fuel pipeline, and a check valve is correspondingly installed on the inter-tank fuel pipeline. By integrating the fuel pipeline, the ventilation pipeline, and the fuel tank accessories, the present invention facilitates the matching of the fuel tank shape with the airframe shape, improves the space utilization rate, and reduces the stress on the fuel tank.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft fuel, and mainly relates to a soft fuel tank fuel system imitating the shape of an aircraft. Background Art

[0002] The aircraft fuel tank is an important structural component of modern aircraft, and its main function is to store the fuel required for aircraft flight. According to different structural forms, aircraft fuel tanks can be roughly divided into three categories: soft fuel tanks, hard fuel tanks, and integral fuel tanks. The main characteristics of soft fuel tanks are as follows: they can be put into the fuel tank compartment of the aircraft through a small hatch, make full use of various available spaces of different shapes inside the aircraft, increase the fuel storage capacity, and are not affected by vibration, and are not prone to cracks or damage. The wall of a common soft fuel tank is composed of an inner lining of oil-resistant rubber and an outer layer of coated fabric. The thickness of some fuel tanks is even less than one millimeter, and the weight is relatively light. Moreover, after being hit by a bullet, the bullet holes are small. Therefore, soft fuel tanks are widely used.

[0003] Currently, the known fuel tank structure is composed of a split fuel tank (front, middle, and rear three split fuel tanks) shell, a fuel filling pipeline, an air pipeline, a fuel tank connector, a pipeline pagoda joint, an oil extractor, and a drain pipeline. The fuel tank shell is connected to the fuel pipeline through a pagoda joint. The fuel tank is filled with fuel through the fuel filling pipeline, and the fuel is filled into multiple split fuel tanks through the fuel tank connector. The internal pressure of the fuel tank is kept balanced with the external atmosphere through the air pipeline; when transporting fuel, the oil extractor is connected to the drain pipeline to transport fuel to specific equipment. However, for the fuel systems of many soft fuel tanks, the fuel filling pipeline and the air pipeline are both distributed outside the fuel tank shell, and fuel filling and ventilation to the atmosphere are realized through external connection. Generally, fuel tanks with pipelines outside need to leave a certain space to arrange the oil pipeline and the air pipeline, and the shape of the fuel tank cannot completely fit the shape of the aircraft body, resulting in low space utilization rate, complex shape, and when the aircraft is overloaded, the oil pipeline and the air pipeline are under pressure, and local stress on the fuel tank is too large. Summary of the Invention

[0004] The present invention provides a soft fuel tank fuel system imitating the shape of an aircraft, which internally arranges the fuel pipeline, the ventilation pipeline, and the fuel tank accessories, facilitating the matching of the fuel tank shape with the aircraft body shape, improving the space utilization rate, and reducing the stress of the fuel tank.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A soft fuel tank fuel system imitating the shape of an aircraft includes a front fuel tank, a middle fuel tank, and a rear fuel tank. A ventilation pipeline is correspondingly provided at one end of the front fuel tank. Pagoda joint connection blocks are correspondingly provided at the tops of the front fuel tank, the middle fuel tank, and the rear fuel tank. A fuel tank interconnection air pipe is correspondingly installed at the pagoda joint connection block, and the interiors of the front fuel tank, the middle fuel tank, and the rear fuel tank are connected and communicated through the fuel tank interconnection air pipe; a fuel filling pipeline is correspondingly installed at the pagoda joint connection block of the rear fuel tank; the bottoms of the front fuel tank, the middle fuel tank, and the rear fuel tank are connected through an inter-tank fuel pipeline, and a one-way valve is correspondingly installed on the inter-tank fuel pipeline.

[0006] Preferably, an oil collecting box for the front fuel tank is correspondingly provided at the bottom end of the front fuel tank, an oil collecting box for the middle fuel tank is correspondingly provided at the bottom end of the middle fuel tank, and an oil collecting box for the rear fuel tank is correspondingly provided at the bottom end of the rear fuel tank.

[0007] Preferably, a lower vent head is correspondingly provided at the bottom of the oil collecting box for the front fuel tank, and the lower vent head is connected to the vent pipeline through Pipeline 15.

[0008] Preferably, an oil drain port is correspondingly provided at the bottom of the oil collecting box for the middle fuel tank, an oil extractor is correspondingly installed in the oil collecting box for the middle fuel tank, and an oil pipeline is correspondingly installed at one end of the oil extractor.

[0009] Preferably, a fuel filling interface is correspondingly installed at one end of the fuel filling pipeline.

[0010] Preferably, an upper vent head is correspondingly installed at one end of the vent pipeline, and the vent pipeline is connected to the inside of the front fuel tank through a gas path three-way joint.

[0011] Preferably, an inverted fuel tank is correspondingly installed inside the middle fuel tank.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0013] In the present invention, by providing a pagoda joint connecting block at the tops of the front fuel tank, the middle fuel tank, and the rear fuel tank, both ends of the gas pipe between the fuel tanks are installed on the pagoda joint connecting block through pagoda joints and are connected to the inside of the fuel tanks, so as to connect the inside of the front fuel tank, the middle fuel tank, and the rear fuel tank. When refueling, fuel is added from the fuel filling interface, and the rear fuel tank is first filled through the fuel filling pipeline; when the rear fuel tank is full, the gas pipe between the fuel tanks on the left side of the top of the rear fuel tank injects the fuel at the top end of the rear fuel tank into the middle fuel tank; when the middle fuel tank is full, the gas pipe between the fuel tanks on the left side of the top of the middle fuel tank injects the fuel at the top end of the middle fuel tank into the front fuel tank until the fuel is full, and the refueling is completed. A gas path three-way joint is provided at the left top of the front fuel tank. One end of the gas path three-way joint is connected to the inside of the front fuel tank, the other end is externally connected to the upper vent head, and the last end is connected to the lower vent head through a pipeline. By controlling the closing state of the upper vent head, the flow of the gas path of the entire fuel tank device is controlled. The pagoda joint connecting block, the gas pipe between the fuel tanks, and the fuel filling pipeline are connected and matched. By connecting the tops of the front fuel tank, the middle fuel tank, and the rear fuel tank, the effect of serving as both an oil path and a gas path is achieved.

[0014] The connection between the gas pipe in the fuel tank compartment and the fuel tank is integrated into the top of the fuel tank, without occupying the space of the fuel tank, with high space utilization rate and simple structure. By setting the flare fitting connection block, the gas pipe in the fuel tank compartment is received in the recess of the flare fitting connection block. When the fuel tank is full of fuel, using the characteristic that the soft fuel tank material is prone to deformation, the flare fitting connection block also deforms. At this time, the gas pipe in the fuel tank compartment is jacked up, and the entire split fuel tank, the gas pipe in the fuel tank compartment and the fuselage are closely attached, matching the shape of the aircraft. When the fuel tank is overloaded, the force received by the fuel tank shell is evenly distributed to the fuselage, and the thin film of the fuel tank shell closely adheres to the inner wall of the fuselage, equivalent to the inner membrane of the fuselage, and no secondary stress will be generated on the fuel tank shell.

[0015] On the other hand, a one-way valve is set on the fuel pipeline between the fuel tanks. By setting the one-way valve, it is ensured that during the fuel transfer and discharge operations of the aircraft, the fuel can only flow from the front fuel tank and the rear fuel tank into the middle fuel tank for fuel transfer or discharge operations, preventing backflow and avoiding affecting the fuel transfer or discharge operation process. Description of the Drawings

[0016] Figure 1 is the overall structural schematic diagram of the soft fuel tank of the present invention;

[0017] Figure 2 is the bottom view structural schematic diagram of the soft fuel tank of the present invention;

[0018] Figure 3 is the front cross-sectional view of the soft fuel tank of the present invention.

[0019] In the figure: 1, front fuel tank; 2, middle fuel tank; 3, rear fuel tank; 4, lower ventilation head; 5, fuel pipeline; 6, fuel filling interface; 7, fuel pipeline between fuel tanks; 8, oil extractor; 9, upper ventilation head; 10, ventilation pipeline; 11, gas path tee joint; 13, gas pipe in the fuel tank compartment; 14, flare fitting connection block; 15, pipeline; 16, fuel filling pipeline; 17, one-way valve; 19, front fuel tank oil collecting box; 20, middle fuel tank oil collecting box; 21, rear fuel tank oil collecting box; 22, fuel discharge port. Detailed Embodiment

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0021] Embodiment, please refer to Figures 1-3, A soft fuel tank fuel system imitating the shape of an airplane, including a front fuel tank 1, a middle fuel tank 2, and a rear fuel tank 3. The fuel tank structure is set as a split fuel tank of the front fuel tank 1, the middle fuel tank 2, and the rear fuel tank 3, making full use of the limited space structure inside the airplane, facilitating the placement of the split fuel tanks inside the fuselage, and better fitting the inner wall of the airplane.

[0022] One end of the front fuel tank 1 is correspondingly provided with a ventilation pipeline 10; a lower ventilation head 4 is correspondingly provided at the bottom of the front fuel tank oil collecting box 19, and the lower ventilation head 4 is connected to the ventilation pipeline 10 through a pipeline 15; an upper ventilation head 9 is correspondingly installed at one end of the ventilation pipeline 10, and the ventilation pipeline 10 is connected to the inside of the front fuel tank 1 through a gas path tee joint 11. By setting a gas path tee joint 11 at the top of the front fuel tank 1, one end of the gas path tee joint 11 is communicated with the inside of the front fuel tank 1, the second end is installed with a ventilation pipeline 10, and the third end is inserted into the front fuel tank 1 and connected to the lower ventilation head 4 through a pipeline 15. Under the action of the gas path tee joint 11, the upper ventilation head 9, the ventilation pipeline 10, the fuel tank inter-pipe 13, and the fuel filling pipeline 16 form an oil pipeline with the top inside each split fuel tank. Specifically, when refueling, refueling is carried out from the fuel filling interface 6, and the rear fuel tank 3 is first filled through the fuel filling pipeline 16; when the rear fuel tank 3 is full, the fuel tank inter-pipe 13 on the left side of the top of the rear fuel tank 3 injects the fuel at the top of the rear fuel tank 3 into the middle fuel tank 2; when the middle fuel tank 2 is full, the fuel tank inter-pipe 13 on the left side of the top of the middle fuel tank 2 injects the fuel at the top of the middle fuel tank 2 into the front fuel tank 1 until the fuel is full, and the refueling is completed. At the same time, under the action of the gas path tee joint 11, the upper ventilation head 9, the ventilation pipeline 10, the fuel tank inter-pipe 13, and the fuel filling pipeline 16 also form a gas pipeline with the top inside each split fuel tank. Specifically, a gas path tee joint 11 is set at the top left of the front fuel tank 1, one end of the gas path tee joint 11 is communicated with the inside of the front fuel tank 1, the other end is externally connected to the upper ventilation head 9, and the last end is connected to the lower ventilation head 4 through a pipeline 15. By controlling the closing state of the upper ventilation head 9, the flow of the gas path of the entire fuel tank device is controlled. Therefore, the pagoda joint connecting block 14, the fuel tank inter-pipe 13, and the fuel filling pipeline 16 are connected and matched, and by connecting the tops of the front fuel tank 1, the middle fuel tank 2, and the rear fuel tank 3, the effect of serving as both an oil pipeline and a gas pipeline is achieved.

[0023] At the top of the front fuel tank 1, middle fuel tank 2, and rear fuel tank 3, there are corresponding tower joint connection blocks 14. At the tower joint connection blocks 14, there are corresponding fuel tank interconnection gas pipes 13 installed. The interiors of the front fuel tank 1, middle fuel tank 2, and rear fuel tank 3 are connected through the fuel tank interconnection gas pipes 13. The inner wall of the tower joint connection block 14 is a bit thinner than the fuel tank wall. By setting the tower joint connection blocks 14 at the top of each split fuel tank, the fuel tank interconnection gas pipes 13 are accommodated in the recesses of the tower joint connection blocks 14 and installed on the inner wall of the aircraft. Specifically, due to the material characteristics of the flexible fuel tank (it is prone to deformation), when the fuel tank is filled with fuel, the inner wall of the tower joint connection block 14, which is a bit thinner than the fuel tank wall, is more likely to deform and bulge upward in the full fuel state. At the same time, the fuel tank interconnection gas pipes 13 accommodated in the recesses of the tower joint connection blocks 14 are pushed upward to closely fit the inner wall of the aircraft, enabling the entire fuel tank to better fit the inner wall of the aircraft and making full use of the limited space of the aircraft.

[0024] The bottoms of the front fuel tank 1, middle fuel tank 2, and rear fuel tank 3 are connected through the fuel tank interconnection oil pipelines 7. One-way valves 17 are correspondingly installed on the fuel tank interconnection oil pipelines 7; at the bottom end of the front fuel tank 1, there is a corresponding front fuel tank oil collecting box 19, at the bottom end of the middle fuel tank 2, there is a corresponding middle fuel tank oil collecting box 20, and at the bottom end of the rear fuel tank 3, there is a corresponding rear fuel tank oil collecting box 21; at the bottom of the middle fuel tank oil collecting box 20, there is a corresponding oil drain port 22. One end of the fuel tank interconnection oil pipeline 7 is connected to the front fuel tank oil collecting box 19, and the other end is connected to the middle fuel tank oil collecting box 20; the other fuel tank interconnection oil pipeline 7 has one end connected to the middle fuel tank oil collecting box 20 and the other end connected to the rear fuel tank oil collecting box 21. The fuel inside the front fuel tank 1, middle fuel tank 2, and rear fuel tank 3 respectively flows into the front fuel tank oil collecting box 19, middle fuel tank oil collecting box 20, and rear fuel tank oil collecting box 21 under the action of gravity. When it is necessary to drain the fuel tank, open the upper ventilation head 9. The fuel in the front fuel tank oil collecting box 19 and rear fuel tank oil collecting box 21 flows into the middle fuel tank oil collecting box 20 through the fuel tank interconnection oil pipeline 7 under the action of gravity, and then open the oil drain port 22 in the middle fuel tank oil collecting box 20 to drain the fuel outwards. By setting the one-way valves 17, it is ensured that the fuel can only flow from the front fuel tank oil collecting box 19 / rear fuel tank oil collecting box 21 into the middle fuel tank oil collecting box 20, preventing backflow and affecting the fuel draining operation.

[0025] A fuel extractor 8 is correspondingly installed inside the middle fuel tank oil collecting box 20. One end of the fuel extractor 8 is correspondingly installed with an oil pipeline 5. One end of the oil pipeline 5 is correspondingly installed with a fuel pump (not shown in the figure). When it is necessary to conduct an oil transfer operation on the fuel tank, open the upper ventilation head 9. The fuel in the front fuel tank oil collecting box 19 and rear fuel tank oil collecting box 21 flows into the middle fuel tank oil collecting box 20 through the fuel tank interconnection oil pipeline 7 under the action of gravity. The fuel concentrated in the middle fuel tank oil collecting box 20 is pumped to the equipment through the fuel extractor 8 under the action of the fuel pump, completing the oil transfer operation.

[0026] A fuel filling pipe 16 is correspondingly installed at the position of the flare fitting connection block 14 of the rear fuel tank 3; one end of the fuel filling pipe 16 is correspondingly installed with a fuel filling interface 6. By providing a flare fitting connection block 14 at one end of the top of the rear fuel tank 3, one end of the fuel filling pipe 16 is inserted into the rear fuel tank 3 through the flare fitting connection block 14, and a fuel filling interface 6 is installed at the other end. Fuel is injected into the front fuel tank 1, the middle fuel tank 2, and the rear fuel tank 3 by filling fuel at the fuel filling interface 6. When the rear fuel tank 3 is full of fuel, the inner wall of the flare fitting connection block 14 deforms and jacks up, and at the same time, the fuel filling pipe 16 stored in the recess of the flare fitting connection block 14 is jacked up to closely fit the inner wall of the aircraft, so that the rear fuel tank 3 better fits on the inner wall of the aircraft.

[0027] An inverted fuel tank is correspondingly installed in the middle fuel tank 2. By specially providing an inverted fuel tank at the lower part of the middle fuel tank 2, during normal flight, the inverted fuel tank is filled with fuel. When the aircraft flies inverted, the fuel in the oil collecting box 20 of the middle fuel tank flows to the upper part of the middle fuel tank 2 and cannot continue to supply fuel. Instead, the inverted fuel tank faces upward and the fuel does not leak. Then the aircraft turns on the inverted fuel tank system and switches to being supplied with fuel by the inverted fuel tank.

[0028] Working principle: When it is necessary to perform a fuel filling operation on the fuel tank, open the lower vent head 4, block the vent head 9 and the drain port 22, and fill fuel from the fuel filling interface 6. First, fill the rear fuel tank 3 through the fuel filling pipe 16; when the rear fuel tank 3 is full, the fuel tank inter-pipe 13 on the left side of the top of the rear fuel tank 3 injects the fuel at the top of the rear fuel tank 3 into the middle fuel tank 2; when the middle fuel tank 2 is full, the fuel tank inter-pipe 13 on the left side of the top of the middle fuel tank 2 injects the fuel at the top of the middle fuel tank 2 into the front fuel tank 1 until fuel leaks out from the lower vent head 4, then stop fuel filling. At the same time, open the upper vent head 9. After stopping the leakage, block the lower vent head 4 and the upper vent head 9, and the fuel filling is completed. When it is necessary to perform a fuel draining operation on the fuel tank, open the upper vent head 9. The fuel in the front fuel tank oil collecting box 19 and the rear fuel tank oil collecting box 21 flows into the middle fuel tank oil collecting box 20 through the fuel tank inter-pipe 7 under the action of gravity, and open the drain port 22 in the middle fuel tank oil collecting box 20 to drain the fuel out, completing the fuel draining. When it is necessary to perform a fuel transfer operation on the fuel tank, open the upper vent head 9. The fuel in the front fuel tank oil collecting box 19 and the rear fuel tank oil collecting box 21 flows into the middle fuel tank oil collecting box 20 through the fuel tank inter-pipe 7 under the action of gravity, and the fuel concentrated in the middle fuel tank oil collecting box 20 is transported to the equipment by the oil extractor 8 under the action of the oil pump, completing the fuel transfer operation.

[0029] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A soft fuel tank fuel system with an aircraft-like shape, comprising a front fuel tank (1), a middle fuel tank (2), and a rear fuel tank (3), characterized in that: One end of the front fuel tank (1) is correspondingly provided with a ventilation pipeline (10). The top ends of the front fuel tank (1), the middle fuel tank (2), and the rear fuel tank (3) are all correspondingly provided with a flare fitting connection block (14). A fuel tank inter-pipe (13) is correspondingly installed at the flare fitting connection block (14), and the interiors of the front fuel tank (1), the middle fuel tank (2), and the rear fuel tank (3) are connected through the fuel tank inter-pipe (13). A fuel filling pipeline (16) is correspondingly installed at the flare fitting connection block (14) of the rear fuel tank (3). The bottoms of the front fuel tank (1), the middle fuel tank (2), and the rear fuel tank (3) are connected through a fuel tank inter-oil pipeline (7), and a check valve (17) is correspondingly installed on the fuel tank inter-oil pipeline (7). A front fuel tank oil sump (19) is correspondingly provided at the bottom end of the front fuel tank (1). A middle fuel tank oil sump (20) is correspondingly provided at the bottom end of the middle fuel tank (2). A rear fuel tank oil sump (21) is correspondingly provided at the bottom end of the rear fuel tank (3). A lower ventilation head (4) is correspondingly provided at the bottom of the front fuel tank oil sump (19), and the lower ventilation head (4) is connected to the ventilation pipeline (10) through a pipeline (15). An upper ventilation head (9) is correspondingly installed at one end of the ventilation pipeline (10), and the ventilation pipeline (10) is connected to the interior of the front fuel tank (1) through an air path tee joint (11). The connection of the fuel tank inter-pipe (13) to the fuel tank is integrated into the top end of the fuel tank. By setting the flare fitting connection block (14), the fuel tank inter-pipe (13) is received in the recess of the flare fitting connection block (14). When the fuel tank is full of fuel, the flare fitting connection block (14) also deforms.

2. The soft fuel tank fuel system with an aircraft-like shape according to claim 1, characterized in that: A drain port (22) is correspondingly provided at the bottom of the middle fuel tank oil sump (20). An oil extractor (8) is correspondingly installed in the middle fuel tank oil sump (20), and an oil pipeline (5) is correspondingly installed at one end of the oil extractor (8).

3. The fuel system of a flexible fuel tank with an aircraft-like shape according to claim 1, characterized in that: A fuel filling interface (6) is correspondingly installed at one end of the fuel filling pipeline (16).

4. A soft fuel tank fuel system with an aircraft-like shape according to claim 1, characterized in that: An inverted fuel tank is correspondingly installed in the middle fuel tank (2).

Images