Fuel oil supply device

Abstract

The fuel oil supply device comprises an oil way switching valve, the oil way switching valve comprises a valve body, a piston and a first elastic piece acting on the piston, the piston keeps the trend of moving towards a filtering cavity, in the initial state, a first oil outlet hole is located in a first cavity, the piston blocks a second oil outlet hole, and the second oil outlet hole is located in a second cavity. The oil inlet hole, the first channel and the first oil outlet hole are in fluid communication to supply oil to a starting oil way of an engine. In the running state, fuel pressure pushes the piston to overcome the elastic force of the first elastic piece to move towards the first cavity and block the first oil outlet, the second oil outlet is located in the second cavity, and the oil inlet and the second oil outlet are in fluid communication to supply oil to a main oil supply path of the engine. According to the device, the piston slowly moves in the fuel oil cavity, slow switching between the first oil outlet hole and the second oil outlet hole is achieved, sudden change of fuel oil pressure at the moment of oil way switching is avoided, the whole process is smooth in operation, the operation stability of an engine is improved, and the success rate of the generator is effectively increased.

Description

Technical Field

[0001] The utility model relates to the technical field of aviation engines, in particular to a fuel supply device. Background Art

[0002] The fuel flow supply system for modern small and medium-sized aircraft engines typically utilizes an electric fuel pump. Due to its high power density and fast response, this type of fuel pump has been a hot topic of research in recent years. Prior art electric fuel pumps include an oil circuit switching valve for controlling the switching of oil circuit channels and a controller for controlling the operation of the oil circuit switching valve. When starting a small and medium-sized aircraft engine, the engine's starting oil circuit is connected to the electric fuel pump's centrifugal starting nozzle. The nozzle atomizes the fuel, which is then ignited by a high-energy igniter, thereby starting the engine. After starting, the electric fuel pump's oil circuit switching valve switches the oil circuit, and the electric fuel pump's venturi nozzle supplies fuel to the engine's main oil supply circuit. However, this type of electric fuel pump has the following problems: at the moment of switching between the starting oil circuit and the main oil supply circuit, the starting oil circuit's pressure suddenly drops, reducing fuel supply and easily leading to engine starting failure. Utility Model Content

[0003] The technical problem to be solved by the present invention is to provide a fuel supply device with a compact structure and smooth switching between the starting oil circuit and the main oil supply circuit in response to the above-mentioned existing technical status, which is particularly suitable for modern small and medium-sized aircraft engines.

[0004] The technical solution adopted by the present invention to solve the above technical problems is as follows: the fuel supply device includes an oil circuit switching valve, which is characterized in that the oil circuit switching valve includes:

[0005] The valve body comprises a filter cavity for filtering fuel and a fuel cavity for accommodating the filtered fuel, wherein the filter cavity is provided with an oil inlet hole, and the fuel cavity is provided with a first oil outlet hole and a second oil outlet hole;

[0006] a piston disposed in the fuel cavity to divide the fuel cavity into a first cavity and a second cavity, the second cavity being in fluid communication with the filter cavity, the piston being provided with a first passage for fuel to flow from the second cavity into the first cavity, and movement of the piston being capable of blocking one of the first oil outlet and the second oil outlet;

[0007] The first elastic member acts on the piston to keep the piston moving toward the filter chamber: in the initial state, the first oil outlet is located in the first cavity, the piston blocks the second oil outlet, and the oil inlet, the first channel and the first oil outlet are fluidically connected to supply oil to the starting oil circuit of the engine; in the running state, the fuel pressure pushes the piston to overcome the elastic force of the first elastic member to move toward the first cavity and block the first oil outlet, the second oil outlet is located in the second cavity, and the oil inlet and the second oil outlet are fluidically connected to supply oil to the main oil supply circuit of the engine.

[0008] Furthermore, the first elastic member is a first spring, and the oil circuit switching valve further includes a housing connected to the valve body via a connector. The first spring is disposed within the housing, with its fixed end secured to the inner wall of the housing. The free end of the first spring is connected to a pressure block. Thus, the first spring presses against the pressure block, increasing the area of interaction with the piston and stabilizing piston movement. The housing can be removed from the valve body, facilitating replacement of different first springs based on the fuel supply characteristics of different engines.

[0009] In order to make the first spring act on the piston, the piston includes a head and a tail portion whose surface portion extends toward the first cavity. The head portion is used to block one of the first oil outlet hole and the second oil outlet hole, and the tail portion extends out of the valve body and is connected to the pressure block through a connecting bolt.

[0010] In order to balance the air pressure inside and outside the housing, preferably, an air vent is provided on the housing so that when the piston overcomes the elastic force of the first spring and moves toward the first cavity, the air in the housing can be discharged from the housing through the air vent.

[0011] In order to supply fuel to the engine, preferably, the first oil outlet is connected to a first connector for connecting to a starting oil circuit of the engine, and the second oil outlet is connected to a second connector for connecting to a main oil supply circuit of the engine.

[0012] To filter the fuel supplied to the engine, a filter element is preferably provided within the filter cavity. The filter element's oil inlet end is connected to the oil inlet port, and a seal is provided between the filter element and the valve body. The filter element removes solid impurities such as iron oxide and dust from the fuel, preventing clogging of the fuel system. The seal ensures that fuel entering the fuel inlet port completely passes through the filter element, preventing a gap between the filter element and the valve body, which could cause some fuel to pass through the gap and weaken the filtration effect.

[0013] To prevent insufficient fuel supply to the fuel system caused by filter clogs, a second elastic member is preferably included. This second elastic member acts on the filter, keeping it moving toward the fuel inlet. When the filter is clogged, fuel pressure pushes the filter away from the fuel inlet, overcoming the force of the second elastic member. This creates a gap between the filter and the valve body for fuel to pass through. In this state, the seal fails, allowing fuel to pass through the gap into the second cavity through the filter cavity, and an alarm is sounded to prompt filter replacement. The second elastic member only activates when the filter is clogged, ensuring an adequate fuel supply when the engine is running.

[0014] Furthermore, the regulating member is a second spring, a first end of the second spring is connected to the inner wall of the valve body, and a second end of the second spring is connected to the filter element.

[0015] Compared with the prior art, the advantages of the present invention are:

[0016] 1. This fuel supply device uses a first elastic member to act on the piston, causing it to maintain a tendency to move toward the filter chamber. Driven by fuel pressure, the piston slowly moves within the fuel chamber to block the second oil outlet, achieving a slow switch between the first and second oil outlets. This avoids sudden changes in fuel pressure during oil circuit switching, ensuring a smooth operation throughout the process, improving engine operation stability and effectively increasing the generator's success rate.

[0017] 2. The first spring acting on the piston and the second spring acting on the filter element are integrated into the oil circuit switching valve, and the device has a small size and weight and a compact structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of an embodiment of the present utility model;

[0019] Figure 2 An exploded view of an embodiment of the present utility model;

[0020] Figure 3 This is a front view of an embodiment of the utility model;

[0021] Figure 4 A top view of an embodiment of the present utility model;

[0022] Figure 5 When the fuel supply device in the embodiment of the utility model is in the initial state Figure 3 Cross-sectional view at point A;

[0023] Figure 6 When the fuel supply device in the embodiment of the utility model is in the initial state Figure 4 Cross-sectional view at point B;

[0024] Figure 7 When the fuel supply device in the embodiment of the utility model is in a stable operating state Figure 3 Cross-sectional view at point A;

[0025] Figure 8 When the fuel supply device in the embodiment of the utility model is in a stable operating state Figure 4 Cross-sectional view at point B;

[0026] Figure 9 When the filter element in the embodiment of the present utility model is in a blocked state Figure 3 Cross-sectional view at point A. DETAILED DESCRIPTION

[0027] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0028] like Figure 1-9 FIG. 1 is a preferred embodiment of the present invention. The fuel supply device of this embodiment includes an oil circuit switching valve 1 , which includes a valve body 2 , a piston 3 , and a first elastic member.

[0029] Among them, the valve body 2 includes a filter chamber 21 for filtering fuel and a fuel chamber 22 for accommodating the filtered fuel. The filter chamber 21 is provided with an oil inlet hole 23, and the fuel chamber 22 is provided with a first oil outlet hole 24 and a second oil outlet hole 25. The first oil outlet hole 24 is connected to a first connector 26 for connecting to the starting oil circuit of the engine, and the second oil outlet hole 25 is connected to a second connector 27 for connecting to the main oil supply circuit of the engine.

[0030] The piston 3 is disposed within the fuel chamber 22 and divides the fuel chamber 22 into a first chamber 221 and a second chamber 222. The second chamber 222 is in fluid communication with the filter chamber 21. The piston 3 is provided with a first channel 31 for fuel to flow from the second chamber 222 into the first chamber 221. The piston 3 includes a head portion 3a and a tail portion 3b extending from the surface of the head portion 3a toward the first chamber 221. The movement of the piston 3 enables the head portion 3a to block one of the first oil outlet 24 and the second oil outlet 25. Under the action of the first elastic member, the piston 3 maintains a tendency to move toward the filter chamber 21. In the initial state, as shown in FIG. Figure 5-6 As shown, the first oil outlet 24 is located in the first cavity 221, the head 3a blocks the second oil outlet 25, and the oil inlet 23, the first channel 31 and the first oil outlet 24 are fluidically connected to supply oil to the starting oil circuit of the engine; in the running state, as shown Figure 7-8 As shown, the fuel pressure pushes the piston 3 to overcome the elastic force of the first elastic member and move toward the first cavity 221. At this time, the head 3a blocks the first oil outlet 24, the second oil outlet 25 is located in the second cavity 222, and the oil inlet 23 and the second oil outlet 25 are fluidically connected to supply oil to the main oil supply circuit of the engine.

[0031] In this embodiment, the first elastic member is a first spring 42, which is disposed within a housing 41. The housing 41 is detachably connected to the valve body 2 via a connector 44. Depending on the engine's fuel supply pattern, the housing 41 can be disassembled to replace the appropriate first spring 42 to meet the desired fuel supply pattern. The fixed end 42a of the first spring 42 is fixed to the inner wall of the housing 41, and the free end 42b is connected to a pressure block 43. The tail portion 3b of the piston 3 extends out of the valve body 2 and is connected to the pressure block 43 via a connecting bolt 45. The first spring 42 presses against the pressure block 43, which acts on the piston 3, increasing the area of interaction with the piston 3 and making the movement of the piston 3 more stable. Furthermore, to balance the air pressure inside and outside the housing 41, an air vent 46 is provided on the housing 41. When the piston 3 moves, air can be discharged from the air vent 46 or enter the housing 41.

[0032] A filter element 211 for filtering fuel is located within the filter chamber 21. The oil inlet end 211a of the filter element 211 is connected to the oil inlet hole 23, and a seal 5 is provided between the filter element 211 and the valve body 2. The filter element 211 removes solid impurities such as iron oxide and dust from the fuel, preventing clogging of the fuel system. The provision of the seal 5 ensures that fuel entering through the oil inlet hole 23 completely passes through the filter element 211, preventing the formation of a gap 6 between the filter element 211 and the valve body 2, which could weaken the filtering effect if some fuel passes through the gap 6. Because the filter element 211 has a limited lifespan, if excessive solid impurities are absorbed, they can clog the filter element 211, reducing the amount of fuel passing through the filter element 211 and causing insufficient fuel supply to the engine. Therefore, the oil circuit switching valve is also provided with a second spring 7, with a first end 7a of the second spring 7 connected to the inner wall of the valve body 2 and a second end 7b connected to the filter element 211. The second spring acts on the filter element 211 to keep the filter element 211 moving toward the oil inlet 23. When the filter element 211 is blocked, Figure 9 As shown, fuel pressure pushes filter element 211 away from oil inlet 23, overcoming the elastic force of the second elastic member. A gap 6 is formed between filter element 211 and valve body 2, allowing fuel to pass through. At this point, seal 5 fails, allowing fuel to pass through gap 6 between filter element 211 and valve body 2, and an alarm is sounded, prompting the user to replace filter element 211. Second spring 7 only activates when filter element 211 is clogged to ensure an adequate fuel supply. After filter element 211 is replaced, the elastic force of second spring 7 causes filter element 211 to move toward oil inlet 23, eliminating gap 6 and allowing fuel to enter fuel chamber 22 after being filtered by filter element 211.

[0033] In summary, the oil circuit adjustment method of the fuel supply device is as follows:

[0034] In the initial state, the first spring 42 acts on the piston 3 to keep the piston 3 moving toward the filter chamber 21. At this time, the head 3a of the piston 3 blocks the second oil outlet 25, and the first oil outlet 24 is located in the first cavity 221. Figure 5-6 As shown, the oil inlet hole 23, the first channel 31 and the first oil outlet hole 24 are fluidically connected to supply oil to the starting oil circuit of the engine.

[0035] In the running state, as the fuel entering the oil circuit regulating device increases, and the oil output of the first oil outlet 24 is limited, the fuel pressure in the second cavity 222 increases, and the fuel pressure pushes the first compression spring 42 to compress, and the head 3a of the piston 3 moves toward the first cavity 221, and the second oil outlet 25 gradually enters the second cavity 222, while the head 3a gradually blocks the first oil outlet 24, and finally gradually reaches the state as shown in FIG. Figure 7-8The head 3a shown blocks the first oil outlet 24, and the second oil outlet 25 is located in the second cavity 222. At this time, the oil inlet 23 and the second oil outlet 25 are fluidically connected to supply oil to the main oil supply circuit of the engine.

[0036] It should be noted that in the description of this embodiment, the terms "front, back", "left, right", "inside, outside", "up, down", etc. indicating directions or positional relationships are all based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention. The terms "install", "connect", and "connected" should be understood in a broad sense. For example, they can be fixedly connected, detachably connected, or integrally connected; they can be directly connected, or indirectly connected through an intermediate medium, or they can be internal connections between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Claims

1. A fuel supply device, comprising an oil circuit switching valve (1), characterized in that: The oil circuit switching valve (1) comprises: The valve body (2) comprises a filter cavity (21) for filtering fuel and a fuel cavity (22) for accommodating filtered fuel, wherein the filter cavity (21) is provided with an oil inlet hole (23), and the fuel cavity (22) is provided with a first oil outlet hole (24) and a second oil outlet hole (25); A piston (3) is provided in the fuel cavity (22) to divide the fuel cavity (22) into a first cavity (221) and a second cavity (222), wherein the second cavity (222) is in fluid communication with the filter cavity (21), and the piston (3) is provided with a first passage (31) for fuel to flow from the second cavity (222) into the first cavity (221), and movement of the piston (3) can block one of the first oil outlet hole (24) and the second oil outlet hole (25); The first elastic member acts on the piston (3) to keep the piston (3) moving toward the filter chamber (21). In the initial state, the first oil outlet (24) is located in the first cavity (221), the piston (3) blocks the second oil outlet (25), and the oil inlet (23), the first channel (31) and the first oil outlet (24) are fluidically connected to supply oil to the engine's starting oil circuit. In the operating state, the fuel pressure pushes the piston (3) to overcome the elastic force of the first elastic member and move toward the first cavity (221) and block the first oil outlet (24). The second oil outlet (25) is located in the second cavity (222), and the oil inlet (23) and the second oil outlet (25) are fluidically connected to supply oil to the engine's main oil supply circuit.

2. The fuel supply device according to claim 1, characterized in that: The first elastic member is a first spring (42). The oil circuit switching valve (1) further comprises a housing (41). The housing (41) is connected to the valve body (2) by means of a connecting member (44). The first spring (42) is arranged in the housing (41) and its fixed end (42a) is fixed to the inner wall of the housing (41). The free end of the first spring (42) is connected to a pressure block (43).

3. The fuel supply device according to claim 2, characterized in that: The piston (3) comprises a head (3a) and a tail (3b) whose surface portion of the head (3a) extends toward the first cavity (221); the head (3a) is used to block one of the first oil outlet hole (24) and the second oil outlet hole (25); and the tail (3b) partially extends out of the valve body (2) and is connected to the pressure block (43) via a connecting bolt (45).

4. The fuel supply device according to claim 3, characterized in that: The housing (41) is provided with an air leakage hole (46).

5. The fuel supply device according to any one of claims 1 to 4, characterized in that: The first oil outlet hole (24) is connected to a first connector (26) for connecting to a starting oil circuit of an engine, and the second oil outlet hole (25) is connected to a second connector (27) for connecting to a main oil supply circuit of an engine.

6. The fuel supply device according to any one of claims 1 to 4, characterized in that: A filter element (211) is provided in the filter cavity (21), an oil inlet end (211a) of the filter element (211) is connected to the oil inlet hole (23), and a sealing member (5) is provided between the filter element (211) and the valve body (2).

7. The fuel supply device according to claim 6, characterized in that: The invention also includes a second elastic member, which acts on the filter element (211) to keep the filter element (211) moving toward the oil inlet hole (23). When the filter element (211) is blocked, the fuel pressure pushes the filter element (211) to overcome the elastic force of the second elastic member and move away from the oil inlet hole (23). A gap (6) for fuel to pass through is formed between the filter element (211) and the valve body (2).

8. The fuel supply device according to claim 7, characterized in that: The second elastic member is a second spring (7), the first end (7a) of the second spring (7) is connected to the inner wall of the valve body (2), and the second end (7b) is connected to the filter element (211).

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