Fuel oil prefilter with exhaust structure and fuel oil assembly

Abstract

The utility model relates to a fuel oil prefilter and a fuel oil assembly with an exhaust structure, the fuel oil prefilter comprises a housing (1), a filter element arranged in the housing (1) and an upper end cover (2) arranged at the upper end of the filter element, the upper end cover (2) is provided with a kidney-shaped hole (3), a hydrophobic screen (4) is arranged on the kidney-shaped hole (3), the filter element comprises a central pipe (5), and the central pipe (5) is provided with an exhaust structure. A water-repellent central pipe (10) is arranged on the inner side of the central pipe (5), and a condensed water filter layer (6) and filter paper (7) are sequentially arranged on the outer side of the central pipe (5). Compared with the prior art, air, moisture and impurities in fuel oil can be efficiently separated through a three-layer filtering structure of a filtering material (filtering paper) with high performance and high dirt capacity, a water gathering filtering material (a water condensing filtering layer) and a water-repellent central pipe, and a waist-shaped hole and a hydrophobic screen structure on the upper end cover, and the filtering precision is improved.

Description

Technical Field

[0001] This utility model relates to the field of automotive engine fuel pre-filter technology, and in particular to a fuel pre-filter with an exhaust structure and a fuel assembly. Background Technology

[0002] Clean fuel can improve combustion efficiency, thereby saving fuel and reducing emissions; it can also reduce abnormal engine wear and extend engine life. In order to ensure the normal operation of the engine, the fuel must first be separated into oil and water and filtered for impurities before it can be sent to the engine. Generally, a fuel pre-filter is used for this process.

[0003] In the fuel supply system, the pre-filter, as a core component for protecting the engine, is generally installed between the fuel tank and the low-pressure fuel pump, and needs to efficiently intercept impurities and moisture in the fuel. For example, Chinese patent CN214513002U discloses a waterproof impurity removal filter element for fuel dispensers, which includes a central tube, a fuel filter paper layer, a non-woven fabric layer, and a steel mesh layer disposed on the outside of the central tube. From the outside to the inside, it realizes a three-stage filtration process of coarse filtration, medium filtration, and fine filtration, which greatly improves the filter element's ability to filter various impurities and colloids.

[0004] However, traditional fuel pre-filters have significant drawbacks under negative pressure conditions: when the pre-filter operates under negative pressure, due to Henry's Law, dissolved air in the fuel easily precipitates and forms bubbles. This precipitated air tends to accumulate on the unfiltered side (dirty side) of the pre-filter element, leading to a low fuel level. This can obstruct fuel flow, causing unstable fuel supply or even engine stalling. Existing filters often rely on a single filter medium and lack a separation structure for the air-fuel mixture. Bubbles easily become trapped in the filter layer gaps, reducing the effective filtration area. Furthermore, the gaseous fuel trapped on the dirty side may flow back to the clean side (filtered side) through the top of the filter element, carrying impurities and contaminating the filtered fuel, causing secondary pollution.

[0005] Therefore, there is an urgent need for a fuel pre-filter with an exhaust structure that can efficiently separate air from fuel. Utility Model Content

[0006] The purpose of this invention is to provide a fuel pre-filter and fuel assembly with an exhaust structure, which can effectively remove air, moisture and impurities from the fuel and has excellent filtration effect.

[0007] The objective of this utility model can be achieved through the following technical solutions:

[0008] This utility model provides a fuel pre-filter with an exhaust structure, including a housing, a filter element disposed inside the housing, and an upper end cap disposed on the upper end of the filter element. The upper end cap is provided with an oblong hole, and a hydrophobic screen is disposed on the oblong hole. The filter element includes a central tube, a water-repellent central tube is disposed inside the central tube, a condensate filter layer is disposed outside the central tube, and filter paper is disposed outside the condensate filter layer.

[0009] Preferably, the outer circumferential side of the filter paper of the filter element is the dirty oil side, the inner cavity of the central tube is the clean oil side, and the waist-shaped hole connects the dirty oil side and the clean oil side.

[0010] Preferably, the upper end cap has an oil outlet in the center, and the oil outlet is connected to the inner cavity of the central tube.

[0011] Preferably, a fuel flow chamber for fuel flow is provided between the cover and the filter element, and an oil inlet is provided on the cover, which is connected to the fuel flow chamber.

[0012] Preferably, the filter element is provided with a lower end cap, and the lower end cap is connected to a water collection cup for collecting water discharged from the fuel.

[0013] Preferably, the bottom of the water collecting cup is also provided with a water level sensor for detecting its water level.

[0014] Preferably, the lower end cap is provided with a water outlet, and a water flow chamber capable of condensing water is provided between the condensate filter layer and the water-repellent central tube. One end of the water outlet is connected to the water flow chamber, and the other end is connected to the water collection cup.

[0015] Preferably, a sealing ring placement groove is provided on the outer side of the lower end cover, and a sealing ring is provided in the sealing ring placement groove.

[0016] Preferably, the outer wall of the water-repellent central tube is provided with a hydrophobic mesh, which is made of PET (polyethylene terephthalate) or PA (polyamide). The water-repellent central tube is used to intercept residual moisture in the fuel.

[0017] Preferably, the condensate filter layer is made of a water-resistant plastic material, including PET, PA, and PES (polyethersulfone), used to agglomerate water in the fuel into droplets.

[0018] Preferably, the filter paper is made of non-woven fabric or meltblown fabric, used to remove impurity particles from fuel oil.

[0019] Preferably, the contact angle of the hydrophobic screen is >90°.

[0020] In this invention, the central tube also provides a certain structural strength support.

[0021] This utility model also provides a fuel assembly including the fuel pre-filter as described above.

[0022] Preferably, the inlet of the fuel pre-filter is connected to the inlet of the fuel assembly, and the outlet of the fuel pre-filter is connected to the fuel pump of the fuel assembly.

[0023] In existing technologies, fuel pre-filters are typically installed between the fuel tank and the fuel pump. The pre-filter operates under negative pressure, which causes a certain amount of air to dissolve in the fuel. When fuel enters the filter element, the filter medium is rapidly wetted within seconds of initial filling due to capillary force in its pore structure. At this point, the filter medium exhibits certain air-permeability resistance, the specific characteristics of which depend on its structure and physical properties. After the machine starts and runs for a period of time, the system gradually reaches a pressure differential equilibrium state. In this state, a portion of the dirty side of the filter element is covered with fuel, while the upper half of the filter element contains only air.

[0024] This utility model provides a fuel pre-filter with an exhaust structure. The upper end cap has a waist-shaped opening, which allows direct communication between the dirty and clean sides of the filter element, promoting the flow of air from the dirty side through the opening along with the fuel from the clean side. Simultaneously, considering that some dirty side fuel may remain on the upper surface of the upper end cap and enter the clean side with the air, this utility model uses a hydrophobic filter screen to ensure that the filtration accuracy is not significantly affected.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) This utility model provides a fuel pre-filter with an exhaust structure, including a filter element and an upper end cover disposed on the upper end of the filter element. The upper end cover is also provided with a waist-shaped hole with a hydrophobic screen, which can efficiently separate air, water and impurities in the fuel and improve the filtration effect.

[0027] (2) This utility model uses a three-layer filtration structure consisting of high-performance, high-pollution-capacity filter material (filter paper), water-repellent filter material (condensate filter layer), and water-repellent central tube to filter impurities and water particles from fuel, thereby achieving a clean and hygienic fuel.

[0028] (3) The upper end cover of this utility model has a waist-shaped hole, which directly connects the dirty oil side and the clean oil side of the fuel pre-filter, promotes air to flow out with the oil outlet, ensures the safety of the filter element's liquid level, and increases the usable area of ​​the filter element.

[0029] (4) The waist-shaped hole of this utility model is provided with a hydrophobic screen. The hydrophobic screen can effectively prevent some of the dirty fuel that remains on the surface of the upper end cap from entering the oil outlet with the air, effectively preventing contamination of clean fuel. The hydrophobic screen can ensure that the filtration accuracy is minimized.

[0030] (5) The hydrophobic screen on the waist-shaped hole of this utility model ensures low water content in fuel and promotes oil-water separation. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the fuel pre-filter with an exhaust structure in Embodiment 2 of this utility model;

[0032] Figure 2 This is a partial enlarged view of the upper end cover of this utility model;

[0033] Figure 3 This is an installation diagram and a diagram showing the flow routes of fuel, air, and water for this utility model (fuel route is indicated by red arrows, air route by green arrows, and water route by blue arrows).

[0034] In the diagram: 1-Cover; 2-Upper cap; 3-Oval hole; 4-Hydrophobic screen; 5-Central tube; 6-Condensate filter layer; 7-Filter paper; 8-Lower cap; 9-Water collection cup; 10-Water-repellent central tube; 11-Sealing ring. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. This embodiment is based on the technical solution of the present invention and provides detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following embodiments.

[0036] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0037] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0038] Unless otherwise specified, the functional components or structures in the following embodiments or examples are conventional components or structures used in the art to achieve the corresponding functions.

[0039] Example 1

[0040] This embodiment provides a fuel pre-filter with an exhaust structure, mainly composed of a housing 1, a filter element, and an upper end cap 2:

[0041] The filter element is installed inside the housing 1, and the upper cover 2 is set above the filter element. The upper cover 2 has a waist-shaped hole 3, and a hydrophobic screen 4 is fixedly installed inside the waist-shaped hole 3.

[0042] The filter element includes a central tube 5, with a condensate filter layer 6 and filter paper 7 arranged sequentially on the outer side of the central tube, and a water-repellent central tube 10 arranged on the inner side.

[0043] Example 2

[0044] This embodiment provides a fuel pre-filter with an exhaust structure, such as Figure 1-3 As shown, the fuel pre-filter consists of a housing 1, a filter element and an upper end cap 2. The filter element is placed inside the housing 1 and the upper end cap 2 is installed on the upper end. The filter element is composed of a central tube 5, and a condensate filter layer 6 for agglomerating water in the fuel into droplets and a filter paper 7 for removing impurity particles in the fuel are arranged in sequence on its outside. A water-repellent central tube 10 for intercepting residual water in the fuel is arranged inside.

[0045] In this embodiment, a hydrophobic mesh is provided on the outer wall of the water-repellent central tube 10. The hydrophobic mesh is made of PET or PA. The condensate filter layer 6 is made of plastic water-resistant material, including PET, PA, and PES. The filter paper 7 is made of non-woven fabric or meltblown fabric. The contact angle of the hydrophobic screen 4 is >90°.

[0046] In this embodiment, a fuel flow chamber for fuel flow is provided between the cover 1 and the filter element. The cover 1 is provided with an oil inlet hole that communicates with the fuel flow chamber. An oil outlet is provided in the center of the upper end cap 2, and the oil outlet communicates with the inner cavity of the central tube 5.

[0047] In this embodiment, a lower end cover 8 is provided at the lower end of the filter element, and a water outlet is provided on the lower end cover 8. A water flow chamber capable of condensing water is provided between the condensate filter layer 6 and the water-repellent central tube 10. The lower end cover 8 is also connected to a water collection cup 9 for collecting water discharged from fuel. One end of the water outlet is connected to the water flow chamber, and the other end is connected to the water collection cup 9. A water level sensor for detecting the water level is also provided at the bottom of the water collection cup 9.

[0048] In this embodiment, the outer circumferential side of the filter paper 7 of the filter element is the dirty oil side, the inner cavity of the central tube 5 is the clean oil side, and the upper end cover 2 is provided with a waist-shaped hole 3. A hydrophobic screen 4 is installed in the hole. The waist-shaped hole 3 connects the dirty oil side and the clean oil side, which promotes the air on the dirty side of the filter element to flow out with the fuel on the clean side through the waist-shaped hole 3. The hydrophobic screen 4 can effectively prevent some of the dirty side fuel that is stuck on the surface of the upper end cover 2 from entering the oil outlet along with the air.

[0049] In this embodiment, a sealing ring placement groove is also provided on the outer side of the lower end cover 8, and a sealing ring 11 is provided in the sealing ring placement groove.

[0050] Example 3

[0051] This embodiment provides a fuel assembly, including the fuel pre-filter with exhaust structure as described in Embodiment 2.

[0052] In this embodiment, the inlet of the fuel pre-filter is connected to the inlet of the fuel assembly, and the outlet of the fuel pre-filter is connected to the fuel pump of the fuel assembly.

[0053] In actual operation, this embodiment, such as Figure 3 As shown, it includes the following steps:

[0054] (1) Fuel enters the fuel pre-filter through the fuel inlet of the fuel assembly. Under the influence of gravity, the fuel falls and accumulates in the fuel flow chamber between the housing 1 and the filter element. At the same time, due to the influence of various factors such as changes in pipe diameter, the solubility of air dissolved in the fuel changes and begins to precipitate. Since the density of air is relatively low, it floats upward against the direction of fuel descent, eventually rising to the highest point of the fuel level.

[0055] (2) When the fuel level reaches the position of the filter paper 7, the filtration process officially begins: the fuel first passes through the filter paper 7 to initially remove impurity particles, then passes through the water-gathering filter material - condensate filter layer 6 to gather small water particles into larger water particles. Subsequently, the fuel enters the inner layer of the filter element through the central tube 5, and passes through the water-repellent central tube 10 with a hydrophobic mesh. The water-repellent central tube 10 intercepts the residual water in the fuel, and finally flows out from the fuel outlet. Due to the hydrophobic mesh on the outer wall of the water-repellent central tube 10 and the influence of gravity, the water discharged from the fuel falls into the water collection cup 9 at the bottom of the cover 1 through the water flow cavity between the condensate filter layer 6 and the water-repellent central tube 10.

[0056] (3) Under the negative pressure operation of the fuel pump in the fuel assembly, the filter element is under negative pressure. The clean fuel filtered by the filter element flows from the outlet to the next component. At the same time, because the oblong hole 3 connects the dirty fuel side and the clean fuel side, under the influence of the higher fuel flow rate and lower pressure at the outlet of the filter element, the air at the highest level of the filter element will enter the clean side of the filter element through the oblong hole 3 of the upper end cover 2 and the hydrophobic screen 4, and flow into the next component position along with the fuel. The hydrophobic screen 4 can effectively prevent some of the dirty fuel remaining on the surface of the upper end cover 2 from entering the outlet along with the air.

[0057] Ideally, the liquid level will be balanced below the highest plane of the upper cover 2, ensuring that only air is present at the waist-shaped hole 3 of the upper cover 2.

[0058] In summary, this utility model improves filtration accuracy and efficiently separates air, moisture and impurities from fuel through a three-layer filtration structure consisting of high-performance, high-pollution-capacity filter material (filter paper), water-repellent filter material (condensate filter layer) and a water-repellent central tube, as well as a waist-shaped hole and hydrophobic screen structure on the upper end cover.

[0059] The above description of the embodiments is provided to enable those skilled in the art to understand and use the utility model. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present utility model is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present utility model without departing from its scope should be within the protection scope of the present utility model.

Claims

1. A fuel prefilter with a vent structure, characterized by, The filter includes a housing (1), a filter element disposed inside the housing (1), and an upper end cap (2) disposed on the upper end of the filter element. The upper end cap (2) is provided with a waist-shaped hole (3), and a hydrophobic screen (4) is provided on the waist-shaped hole (3). The filter element includes a central tube (5), a water-repellent central tube (10) is provided inside the central tube (5), a condensate filter layer (6) is provided outside the central tube (5), and a filter paper (7) is provided outside the condensate filter layer (6).

2. The fuel pre-filter with exhaust structure according to claim 1, characterized in that, The filter paper (7) of the filter element has a dirty oil side on the outer circumference and a clean oil side inside the central tube (5). The waist-shaped hole (3) connects the dirty oil side and the clean oil side.

3. The fuel pre-filter with exhaust structure according to claim 1, wherein The upper end cap (2) has an oil outlet in the center, which is connected to the inner cavity of the central tube (5).

4. The fuel pre-filter with exhaust structure according to claim 1, wherein A fuel flow chamber for fuel flow is provided between the cover (1) and the filter element. An oil inlet hole is provided on the cover (1), and the oil inlet hole is connected to the fuel flow chamber.

5. The fuel prefilter with a venting structure according to claim 1, wherein The filter element is provided with a lower end cover (8) at the lower end, and the lower end cover (8) is connected to a water collection cup (9) for collecting water discharged from the fuel. The bottom of the water collection cup (9) is also provided with a water level sensor for detecting its water level.

6. The fuel prefilter with a venting structure according to claim 5, wherein The lower end cap (8) is provided with a water outlet. A water flow chamber capable of condensing water is provided between the water condensation filter layer (6) and the water repellent central tube (10). One end of the water outlet is connected to the water flow chamber, and the other end is connected to the water collection cup (9).

7. The fuel prefilter with a venting structure according to claim 5, wherein A sealing ring placement groove is provided on the outer side of the lower end cover (8), and a sealing ring (11) is provided in the sealing ring placement groove.

8. The fuel prefilter with a venting structure of claim 1, wherein, The outer wall of the water-repellent central tube (10) is provided with a hydrophobic mesh, which is selected from either PET or PA. The water-repellent central tube (10) is used to intercept residual water in the fuel.

9. A fuel pre-filter with an exhaust structure according to claim 1, characterized in that, The condensate filter layer (6) is made of any one of PET, PA or PES and is used to agglomerate water in fuel into droplets; the filter paper (7) is made of any one of non-woven fabric or meltblown fabric and is used to remove impurity particles in fuel; the contact angle of the hydrophobic screen (4) is >90°.

10. A fuel system comprising a fuel pre-filter with an exhaust structure as described in any one of claims 1-9, wherein the fuel pre-filter's inlet is connected to the fuel inlet of the fuel system, and the fuel pre-filter's outlet is connected to the fuel pump of the fuel system.

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