Structure for eliminating water hammer of fuel pump outlet flap valve

Abstract

The utility model discloses a water hammer eliminating structure of a fuel pump outlet flap valve. A valve plate (5) is rotationally connected to the valve seat (1), and a channel of the valve seat (1) can be closed after the valve plate (5) is rotationally closed; a buffer cavity (2) is arranged beside a channel opening edge of the valve seat (1), a buffer piston (3) is movably connected in the buffer cavity (2), the top end of the buffer piston (3) extends out of the top end of the buffer cavity (2), and the bottom end of the buffer cavity (2) is communicated with a channel of the valve seat (1) through a flow limiting hole (4). And the valve plate (5) can be in contact with the buffer piston (3) when being rotationally closed, and pushes the buffer piston (3) to move along the buffer cavity (2). The speed of the final closing stroke of the valve can be reduced, the closing time of the valve is delayed, the pressure in front of and behind the valve is balanced, and the water hammer effect is eliminated.

Description

Technical Field

[0001] This utility model relates to the field of aviation fuel pump technology, and in particular to a structure for eliminating water hammer by a fuel pump outlet flap valve. Background Technology

[0002] The fuel pump is a core component of the aviation fuel system. To improve the reliability and maintainability of the fuel pump, it is generally designed as a split structure that can be disassembled into a pump housing and a pump core.

[0003] To achieve the self-sealing function during assembly and disassembly, the pump casing outlet is often equipped with a flap valve, which is a one-way valve structure. When the pump core is removed, the pump casing outlet flap valve closes, preventing external fuel from entering the pump casing. When the pump core is installed and in operation, the pump casing outlet one-way valve is pushed open by the high-pressure fuel to be pumped out, so as to deliver fuel to the outside of the pump.

[0004] Currently, pump casing outlet flap valves have the advantages of low opening pressure and low flow resistance. However, at the moment the pump closes, the high-pressure fuel suddenly disappears, and the valve plate of the outlet flap valve closes rapidly under the combined action of spring force and high-pressure fuel after the pump, causing a large fluid impact force, also known as water hammer. This causes significant impact on the fuel system pipelines, affecting the safety and lifespan of the fuel system. Therefore, in the design, it is desirable for the pump casing outlet flap valve to have the characteristics of rapid opening and slow closing (fast opening, slow closing). Utility Model Content

[0005] The purpose of this invention is to provide a structure for eliminating water hammer on a fuel pump outlet flap valve. This invention can reduce the speed of the valve's final closing stroke and delay the valve closing time, thereby balancing the pressure before and after the valve and eliminating the water hammer effect.

[0006] The technical solution of this utility model is: a structure for eliminating water hammer by a fuel pump outlet flap valve, including a valve seat, a valve plate rotatably connected to the valve seat, and the valve seat channel being closed after the valve plate is rotated closed; a buffer cavity is provided beside the valve seat channel opening, and a buffer piston is movably connected inside the buffer cavity, with the top of the buffer piston extending out of the top of the buffer cavity, and the bottom of the buffer cavity communicating with the valve seat channel through a flow limiting hole; when the valve plate is rotated closed, it can contact the buffer piston and push the buffer piston to move along the buffer cavity.

[0007] In the aforementioned structure for eliminating water hammer using a fuel pump outlet flap valve, the valve plate is closed and reset by a reset torsion spring located on the hinge shaft.

[0008] In the aforementioned structure for eliminating water hammer using a fuel pump outlet flap valve, a pressure ring is provided at the edge of the valve seat channel. After the valve plate rotates and closes, it is pressed against the pressure ring.

[0009] In the aforementioned structure for eliminating water hammer using a fuel pump outlet flap valve, the diameter of the flow-limiting orifice is smaller than the diameter of the buffer chamber.

[0010] In the aforementioned structure for eliminating water hammer using a fuel pump outlet flap valve, after the valve plate is rotated open, the top of the buffer piston is higher than the top end face of the pressure ring.

[0011] In the aforementioned structure for eliminating water hammer using a fuel pump outlet flap valve, a buffer pad is provided at the top of the buffer piston.

[0012] The advantages of this invention are: when the outlet flap valve is closed, the valve plate first presses on the buffer piston when it returns to its original position, reducing the speed of the valve's final closing stroke and delaying the valve's closing time. This allows the pressure before and after the valve to be balanced, eliminating the water hammer effect, reducing the impact force of water hammer on the fuel system pipeline, and improving the safety of the fuel system. Attached Figure Description

[0013] Figure 1 This is a structural cross-sectional view of the present invention;

[0014] Figure 2 This is a three-dimensional structural diagram of the present invention. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0016] Example 1. A structure for eliminating water hammer using a fuel pump outlet flap valve, configured as follows: Figure 1 and 2 As shown, it includes a valve seat 1, on which a valve plate 5 is rotatably connected. When the valve plate 5 is rotated and closed, it can close the channel of the valve seat 1. A buffer cavity 2 is provided next to the channel opening of the valve seat 1. A buffer piston 3 is movably connected in the buffer cavity 2. The top end of the buffer piston 3 extends out of the top end of the buffer cavity 2. The bottom end of the buffer cavity 2 is connected to the channel of the valve seat 1 through a flow limiting hole 4. When the valve plate 5 is rotated and closed, it can contact the buffer piston 3 and push the buffer piston 3 to move along the buffer cavity 2.

[0017] The aforementioned door panel 5 is closed and reset by a reset torsion spring 8 located on the hinge shaft 7.

[0018] The aforementioned valve seat 1 has a pressure ring 6 at the edge of the channel opening. After the valve plate 5 is rotated and closed, it is pressed onto the pressure ring 6.

[0019] The diameter of the aforementioned flow-limiting orifice 4 is smaller than the diameter of the buffer chamber 2.

[0020] After the aforementioned valve plate 5 is rotated open, the top of the buffer piston 3 is higher than the top end face of the pressure ring 6.

[0021] The aforementioned buffer piston 3 has a buffer pad at its top.

[0022] Valve closing process:

[0023] When the fuel pump is turned off, the high-pressure fuel output by the pump disappears, and the valve plate 5 rotates rapidly under the combined action of the spring force and the high-pressure fuel behind the valve, thus closing the valve.

[0024] The valve plate 5 first contacts the top of the buffer piston 3, and the buffer piston 3 is subjected to the pressure of the valve plate 5, and begins to move downward in a straight line within the buffer chamber 2.

[0025] The buffer chamber 2 contains fuel, and the buffer piston 3 moves down to compress the fuel and it flows out through the flow-limiting orifice 4.

[0026] Fuel is a fluid and can be approximated as incompressible. The diameter of the flow-limiting orifice 4 is much smaller than the diameter of the buffer piston 3, which limits the speed at which the fuel flows out, and thus limits the speed at which the buffer piston 3 moves downward.

[0027] The downward movement speed of the buffer piston 3 is limited, which restricts the closing speed of the valve plate 5.

[0028] After the fuel in the buffer chamber 2 is completely discharged, the buffer piston 3 moves down to the lowest end, the top of the buffer piston 3 disengages from the valve plate, and the valve plate presses on the pressure ring 6 of the valve seat 1, and the valve is completely closed.

[0029] The process of opening the valve:

[0030] When the fuel pump is turned on, the high-pressure fuel output by the pump is directly used on the valve plate 5 to open the valve and open the valve. This invention will not affect the opening of the valve.

[0031] At the same time, the high-pressure fuel output by the pump enters the buffer chamber 2 through the flow limiting hole 4, pushing the buffer piston 3 to move upward. The top of the buffer piston 3 is higher than the pressure ring of the valve seat 1, preparing to receive the valve plate 5 when the valve is closed.

Claims

1. A structure for eliminating water hammer at the outlet of a fuel pump, characterized in that, Includes a valve seat (1), on which a valve plate (5) is rotatably connected. When the valve plate (5) is rotated and closed, it can close the channel of the valve seat (1). A buffer cavity (2) is provided beside the channel opening of the valve seat (1). A buffer piston (3) is movably connected inside the buffer cavity (2). The top of the buffer piston (3) extends out of the top of the buffer cavity (2). The bottom of the buffer cavity (2) is connected to the channel of the valve seat (1) through a flow limiting hole (4). When the valve plate (5) is rotated and closed, it can contact the buffer piston (3) and push the buffer piston (3) to move along the buffer cavity (2).

2. The structure for eliminating water hammer at the fuel pump outlet flap valve according to claim 1, characterized in that: The valve plate (5) is closed and reset by a reset torsion spring (8) located on the hinge shaft (7).

3. The structure for eliminating water hammer at the fuel pump outlet flap valve according to claim 1, characterized in that: A pressure ring (6) is provided at the edge of the passage of the valve seat (1). After the valve plate (5) is rotated and closed, it is pressed onto the pressure ring (6).

4. The structure for eliminating water hammer at the fuel pump outlet flap valve according to claim 1, characterized in that: The diameter of the flow-limiting orifice (4) is smaller than the diameter of the buffer chamber (2).

5. The structure for eliminating water hammer at the fuel pump outlet flap valve according to claim 3, characterized in that: After the valve plate (5) is rotated open, the top of the buffer piston (3) is higher than the top end face of the pressure ring (6).

6. The structure for eliminating water hammer at the fuel pump outlet flap valve according to claim 1, characterized in that: The top of the buffer piston (3) is equipped with a buffer pad.

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