Multifunctional pressure reduction valve combined structure for fuel oil supply pump

Abstract

The utility model discloses a multifunctional pressure reduction valve combined structure for a fuel oil supply pump. Comprising a decompression chamber shell, a pressure relief cavity and a pressure cavity are designed in the decompression chamber shell in the axial direction, the pressure relief cavity is communicated with an inlet of a fuel oil supply pump, and the pressure cavity is communicated with an outlet of the fuel oil supply pump; the decompression chamber shell is connected with the sealing cover; a sealing opening is formed in the joint of the pressure relief cavity and the pressure cavity, a pressure reduction valve is arranged at the sealing opening, one end of the pressure reduction valve is slidably connected with a sliding cavity A arranged in the pressure cavity, and the other end of the pressure reduction valve is connected with a diaphragm assembly arranged on the opening end face of the pressure relief cavity; the sealing cover is provided with a pressure sensing cavity, and the pressure sensing cavity is communicated with the atmosphere; the pressure sensing cavity, the pressure relief cavity and the pressure cavity are sequentially and coaxially arranged, and the pressure sensing cavity and the pressure relief cavity are isolated through the diaphragm assembly. The utility model meets the requirements of reliable work, small volume and light weight.

Description

Technical Field

[0001] The utility model belongs to the technical field of structural design of a fuel supply pump for a fuel system of a low-power engine, and particularly relates to a multifunctional pressure-reducing valve combination structure for a fuel supply pump. Background Art

[0002] The fuel supply pump is a major component of the engine's fuel system and is an indispensable functional component for the engine to function.

[0003] In current low-power engine fuel systems, the fuel pump has a low flow rate. To meet the fuel consumption requirements of the engine at high altitudes and at different engine speeds, a pressure relief valve is typically installed after the fuel pump to ensure stable flow output under different conditions. Due to the low output flow rate, a special pressure relief valve structure is required to achieve precise regulation. Utility Model Content

[0004] The purpose of this utility model is to provide a multifunctional pressure reducing valve assembly structure for a fuel supply pump. The utility model satisfies the requirements of reliable operation, small size and light weight, while solving the problem of accurate output of fuel flow in different states of existing small flow fuel pumps.

[0005] The technical solution of the utility model is: a multifunctional pressure reducing valve combination structure for a fuel supply pump, comprising a pressure reducing chamber housing, a pressure relief chamber and a pressure chamber designed axially in the pressure reducing chamber housing, the pressure relief chamber being connected to the inlet of the fuel supply pump, and the pressure chamber being connected to the outlet of the fuel supply pump; the pressure reducing chamber housing is connected to a sealing cover; the connection between the pressure relief chamber and the pressure chamber is a sealing port, a pressure reducing valve is provided at the sealing port, one end of the pressure reducing valve is slidably connected to a sliding chamber A arranged in the pressure chamber, and the other end is connected to a diaphragm assembly arranged on an opening end face of the pressure relief chamber; the sealing cover is provided with a pressure sensing chamber, and the pressure sensing chamber is connected to the atmosphere; the pressure sensing chamber, the pressure relief chamber and the pressure chamber are coaxially arranged in sequence, and the pressure sensing chamber and the pressure relief chamber are isolated by the diaphragm assembly.

[0006] In the aforementioned multifunctional pressure reducing valve combination structure for the fuel supply pump, exhaust holes that can connect the pressure relief chamber and the pressure chamber are distributed circumferentially on the pressure reducing valve sealing disk. In the initial state, the opening of the exhaust hole on the side of the pressure chamber is sealed by a sealing bushing. The sealing bushing can slide on the sliding end of the pressure reducing valve in the pressure chamber, and a pressure reducing spring is provided between the sealing bushing and the bottom surface of the pressure chamber.

[0007] In the aforementioned multifunctional pressure reducing valve assembly structure for the fuel supply pump, an adjusting component for adjusting the preload force of the pressure reducing valve is further provided in the pressure sensing chamber.

[0008] In the aforementioned multifunctional pressure reducing valve combination structure for the fuel supply pump, the adjustment assembly includes a threaded cavity and a sliding cavity B arranged in sequence in the axial direction from the outside to the inside in the cover; an adjusting nut is threadedly connected in the threaded cavity, and a spring seat is slidably connected in the sliding cavity B. The end face of the spring seat abuts against the diaphragm assembly and is coaxially arranged with the pressure reducing valve. A pressure regulating spring is provided between the adjusting nut and the spring seat.

[0009] In the aforementioned multifunctional pressure reducing valve assembly structure for the fuel supply pump, the center of the adjusting nut is slidably connected to the adjusting rod.

[0010] In the aforementioned multifunctional pressure reducing valve assembly structure for the fuel supply pump, the inner step plane of the end step of the adjusting rod abuts against the outer end surface of the threaded cavity, and the end step of the adjusting rod is covered with a cap, which is threadedly connected to the sealing cover.

[0011] The advantages of the utility model are:

[0012] The pressure reducing valve combination structure of the present invention, on the one hand, when exhausting the fuel system before starting the engine, only needs to introduce fuel of a certain pressure into the inlet of the fuel supply pump to fill the pressure relief chamber, open the sealing bushing, and let the fuel flow into the outlet of the fuel supply pump through the exhaust hole on the pressure reducing valve, without adding other accessories, thereby reducing the workload of the operator; on the other hand, the pressure reducing valve combination structure composed of the pressure regulating spring, the diaphragm assembly, the pressure reducing spring, etc., because the diaphragm assembly senses the atmospheric pressure and the fuel pressure at the same time, and the deformation value of the diaphragm assembly has little effect on the pressure change, it can meet the fuel consumption requirements of the engine under high altitude conditions, and realize the precise output of fuel flow of the small-flow fuel pump at different altitudes. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural diagram of the present utility model. DETAILED DESCRIPTION

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0015] Example 1. A multifunctional pressure reducing valve assembly structure for a fuel supply pump, see Figure 1, including a decompression chamber shell 1, in which a pressure relief chamber 2 and a pressure chamber 16 are designed axially, the pressure relief chamber 2 is connected to the inlet of the fuel supply pump, and the pressure chamber 16 is connected to the outlet of the fuel supply pump; the decompression chamber shell 1 is connected to the cover 4; the connection between the pressure relief chamber 2 and the pressure chamber 16 is a sealed port, and a pressure relief valve 5 is provided at the sealed port, one end of the pressure relief valve 5 is slidably connected to the sliding chamber A18 arranged in the pressure chamber 16, and the other end is connected to the diaphragm assembly 3 arranged on the open end face of the pressure relief chamber 2; the cover 4 is provided with a pressure sensing chamber 6, and the pressure sensing chamber 6 is connected to the atmosphere; the pressure sensing chamber 6, the pressure relief chamber 2 and the pressure chamber 16 are coaxially arranged in sequence, and the pressure sensing chamber 6 and the pressure relief chamber 2 are isolated by the diaphragm assembly 3.

[0016] When the outlet pressure of the fuel supply pump exceeds the pressure during engine startup, the pressure in the pressure chamber 16 connected to the outlet of the fuel supply pump also exceeds the pressure. At this time, the pressure pushes the pressure reducing valve 5 out of the sealing port, and the pressure chamber 16 is connected to the pressure relief chamber 2. The over-pressured fuel flows back to the fuel supply pump through the inlet of the fuel supply pump connected to the pressure relief chamber 2.

[0017] The diaphragm assembly 3 is designed to isolate the fuel and atmosphere, preventing the fuel in the fuel supply pump from flowing out; on the other hand, it senses the atmospheric pressure and fuel pressure. As the flight altitude increases, the atmospheric pressure decreases, but the performance of the fuel supply pump also decreases. Due to the presence of the diaphragm assembly 3, the outlet pressure of the fuel supply pump can still be maintained within the required range.

[0018] The aforementioned pressure reducing valve 5 sealing disk is circumferentially distributed with exhaust holes 14 that can connect the pressure relief chamber 2 and the pressure chamber 16. In the initial state, the exhaust hole 14 is located on the side of the pressure chamber 16 and is sealed by a sealing bushing 15. The sealing bushing 15 can slide on the sliding end of the pressure reducing valve 5 in the pressure chamber 16. A pressure reducing spring 17 is provided between the sealing bushing 15 and the bottom surface of the pressure chamber 16.

[0019] Before starting the engine, the fuel system is vented. The venting steps are as follows: the inlet of the fuel supply pump injects oil into the pressure relief chamber 2. When the pressure reaches the preset pressure, the fuel pushes open the sealing bushing 15 through the vent hole 14 and enters the pressure chamber 16. At this time, the pressure relief chamber 2 is connected to the pressure chamber 16, and the air in the system is discharged through the outlet of the fuel supply pump connected to the pressure chamber 16.

[0020] The aforementioned pressure sensing chamber 6 is also provided with an adjustment component for adjusting the preload force of the pressure reducing valve 5 .

[0021] The aforementioned adjustment assembly comprises a threaded cavity 7 and a sliding cavity B12, arranged axially inward from the outside in the cover 4. An adjusting nut 9 is threadedly connected to the threaded cavity 7, and a spring seat 13 is slidably connected to the sliding cavity B12. The end face of the spring seat 13 abuts against the diaphragm assembly 3 and is coaxially arranged with the pressure-reducing valve 5. A pressure-regulating spring 11 is interposed between the adjusting nut 9 and the spring seat 13. The adjustment assembly is used to adjust the overpressure threshold of the fuel supply pump's outlet pressure. The adjustment process is as follows: When the adjusting nut 9 is rotated, it moves axially along the threaded cavity 7, thereby compressing or relaxing the pressure-regulating spring 11, adjusting the preload force of the pressure-reducing valve 5 and ultimately adjusting the overpressure threshold of the fuel supply pump's outlet pressure.

[0022] The center of the aforementioned adjusting nut 9 is slidably connected to the adjusting rod 8.

[0023] The inner step plane of the end step of the aforementioned adjusting rod 8 abuts against the outer end surface of the threaded cavity 7, and the end step of the adjusting rod 8 is covered with a cap 10, which is threadedly connected to the cover 4. The cap 10 limits the displacement of the adjusting rod 8 to achieve the purpose of preventing loosening.

Claims

1. A multifunctional pressure reducing valve assembly structure for a fuel supply pump, characterized in that: The invention comprises a decompression chamber housing (1), wherein a pressure relief chamber (2) and a pressure chamber (16) are axially arranged in the decompression chamber housing (1), wherein the pressure relief chamber (2) is communicated with the inlet of the fuel supply pump, and the pressure chamber (16) is communicated with the outlet of the fuel supply pump; the decompression chamber housing (1) is connected to a cover (4); the connection between the pressure relief chamber (2) and the pressure chamber (16) is a sealed port, and a pressure relief valve (5) is provided at the sealed port, wherein one end of the pressure relief valve (5) is slidably connected to a sliding chamber A (18) provided in the pressure chamber (16), and the other end is connected to a diaphragm assembly (3) provided on the open end face of the pressure relief chamber (2); the cover (4) is provided with a pressure sensing chamber (6), and the pressure sensing chamber (6) is communicated with the atmosphere; the pressure sensing chamber (6), the pressure relief chamber (2) and the pressure chamber (16) are coaxially arranged in sequence, and the pressure sensing chamber (6) and the pressure relief chamber (2) are isolated by the diaphragm assembly (3).

2. The multifunctional pressure reducing valve assembly structure for a fuel supply pump according to claim 1, characterized in that: The sealing disk of the pressure relief valve (5) is provided with exhaust holes (14) which can communicate with the pressure relief chamber (2) and the pressure chamber (16). In the initial state, the opening of the exhaust hole (14) on the side of the pressure chamber (16) is sealed by a sealing bushing (15). The sealing bushing (15) can slide on the sliding end of the pressure relief valve (5) in the pressure chamber (16). A pressure relief spring (17) is provided between the sealing bushing (15) and the bottom surface of the pressure chamber (16).

3. The multifunctional pressure reducing valve assembly structure for a fuel supply pump according to claim 1, characterized in that: The pressure sensing chamber (6) is also provided with an adjustment component for adjusting the preload force of the pressure reducing valve (5).

4. The multifunctional pressure reducing valve assembly structure for a fuel supply pump according to claim 3, characterized in that: The regulating assembly comprises a threaded cavity (7) and a sliding cavity B (12) which are arranged in sequence in the axial direction from the outside to the inside in the sealing cover (4); an regulating nut (9) is threadedly connected to the threaded cavity (7), and a spring seat (13) is slidably connected to the sliding cavity B (12); the end face of the spring seat (13) abuts against the diaphragm assembly (3) and is coaxially arranged with the pressure reducing valve (5); a pressure regulating spring (11) is provided between the regulating nut (9) and the spring seat (13).

5. The multifunctional pressure reducing valve assembly structure for the fuel supply pump according to claim 4, characterized in that: The center of the adjusting nut (9) is slidably connected to the adjusting rod (8).

6. The multifunctional pressure reducing valve assembly structure for a fuel supply pump according to claim 5, characterized in that: The inner step plane of the end step of the regulating rod (8) abuts against the outer end surface of the threaded cavity (7), and the end step of the regulating rod (8) is covered with a cap (10), which is threadedly connected to the sealing cover (4).

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