A diesel fuel system

Abstract

The application discloses a diesel engine fuel system, which is used for preventing air from entering a fuel injection pump, reducing the influence of air on fuel supply of the fuel injection pump and improving starting efficiency of the diesel engine. The diesel engine fuel system comprises an oil tank, a fuel injection pump, a first control valve, a second control valve and a fuel injector. The oil tank is connected with an oil inlet and an oil return port of the fuel injection pump through oil pipes respectively, and the fuel injection pump is used for providing fuel with a preset pressure. The fuel injector is connected with the fuel injection pump, and the fuel injector is used for spraying the fuel provided by the fuel injection pump into a cylinder. The first control valve is located in front of the oil inlet of the fuel injection pump, and the first control valve is used for controlling opening and closing of the oil inlet of the fuel injection pump. The second control valve is located behind the oil return port of the fuel injection pump, and the second control valve is used for controlling opening and closing of the oil return port of the fuel injection pump.

Description

Technical Field

[0001] This application relates to the field of engine technology, and more particularly to a diesel engine fuel system. Background Technology

[0002] A diesel engine is an internal combustion engine that uses diesel fuel. When a diesel engine is working, it needs to inject and atomize the fuel. If air enters the fuel injection pump during this atomization process, it can cause malfunctions such as difficulty starting or stalling during operation. There are two ways air can enter the fuel injection pump: one is that when the diesel engine is running, the suction of the fuel pump on the injection pump creates a negative pressure in the fuel line. When the diesel engine stops, the air dissolved in the fuel will precipitate and enter the injection pump; the other is that when the diesel engine stops running, the air in the return fuel line will be drawn back into the injection pump and fuel filter, resulting in air in the injection pump but no fuel.

[0003] In existing technology, air is purged from the fuel injection pump and fuel lines to prevent air from affecting the fuel injection pump during diesel engine startup, thereby reducing engine malfunctions. In practice, this involves first opening the bleed valve on the fuel filter and manually pressing the fuel pump to expel air and some fuel through the bleed valve.

[0004] However, manually pressing the fuel pump to bleed air takes a certain amount of time, resulting in low starting efficiency of the diesel engine. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides a diesel engine fuel system that prevents air from entering the fuel injection pump, reduces the impact of air on the fuel injection pump, and improves the starting efficiency of the diesel engine.

[0006] This application provides a diesel engine fuel system, comprising:

[0007] The system comprises a fuel tank, a fuel injection pump, a first control valve, a second control valve, and a fuel injector. The fuel tank is connected to the fuel injection pump's inlet and outlet via fuel lines. The fuel injection pump provides fuel at a preset pressure. The fuel injector is connected to the fuel injection pump and injects the fuel supplied by the pump into the cylinder. The first control valve is located in front of the fuel injection pump's inlet and controls the opening and closing of the fuel inlet. The second control valve is located behind the fuel injection pump's outlet and controls the opening and closing of the fuel return.

[0008] Optionally, the diesel engine fuel system further includes a fuel filter;

[0009] The fuel filter is located between the fuel tank and the first control valve, and the fuel filter is used to filter impurities in the fuel.

[0010] Optionally, the fuel filter is provided with a vent plug, which is used to remove air from the fuel line when loosened.

[0011] Optionally, the first control valve is integrated into the fuel filter or the fuel injection pump.

[0012] Optionally, both the first control valve and the second control valve are one-way valves.

[0013] Optionally, the opening pressure range of the first control valve and the second control valve is 0-15 kPa.

[0014] Optionally, the diesel engine fuel system further includes a fuel distributor;

[0015] The fuel distributor is located between the fuel injection pump return port and the fuel tank, and the fuel distributor is used to store fuel and isolate air intake.

[0016] Optionally, the second control valve is integrated into the return port of the fuel injection pump.

[0017] Optionally, the diesel engine fuel system also includes a fuel pump;

[0018] The fuel pump is located between the fuel tank and the first control valve, and the fuel pump is used to increase the fuel flow rate.

[0019] Optionally, the oil pump is an electronic oil pump.

[0020] As can be seen from the above technical solutions, this application has the following effects:

[0021] The first control valve is located between the fuel tank and the fuel injection pump inlet, and the second control valve is located between the fuel tank and the fuel injection pump return port. By controlling the opening and closing of the first and second control valves, fuel can be controlled to flow only from the fuel tank to the fuel injection pump inlet and from the fuel injection pump return port back to the fuel tank. This prevents air released from negative pressure in the pipeline and air in the return pipeline from re-entering the fuel injection pump, reducing the impact of air on the fuel injection pump and improving the starting efficiency of the diesel engine. Attached Figure Description

[0022] Figure 1 A schematic diagram of a diesel engine fuel system provided in this application. Detailed Implementation

[0023] This application provides a diesel engine fuel system to prevent air released from negative pressure in the pipeline and air from the return fuel line from entering the fuel injection pump, thereby reducing the impact of air on the fuel injection pump's fuel supply and improving the diesel engine's starting efficiency. The specific implementation process of this application is described below.

[0024] Please see Figure 1 , Figure 1 This is a schematic diagram of the diesel engine fuel system provided in this application, which includes:

[0025] The system includes a fuel tank 2, a fuel injection pump 1, a first control valve 3, a second control valve 4, and a fuel injector 5. The fuel tank 2 is connected to the fuel inlet 11 and the fuel return port 12 of the fuel injection pump 1 via a fuel supply pipe 9. The fuel injection pump 1 is used to provide fuel at a preset pressure. The fuel injector 5 is connected to the fuel injection pump 1 and is used to inject the fuel provided by the fuel injection pump 1 into the cylinder. The first control valve 3 is located in front of the fuel inlet 11 of the fuel injection pump 1 and is used to control the opening and closing of the fuel inlet of the fuel injection pump 1. The second control valve 4 is located behind the fuel return port 12 of the fuel injection pump 1 and is used to control the opening and closing of the fuel return of the fuel injection pump 1.

[0026] One end of the injector 5 is connected to the injection pump 1, and the other end is directed into the working cylinder of the diesel engine. In actual use, the injection pump 1 increases the diesel fuel pressure to a preset pressure value, and then the injector 5 atomizes the fuel at the preset pressure value and injects it into the cylinder, so that the cylinder can successfully ignite according to the atomized fuel.

[0027] The fuel injection pump 1 is equipped with an inlet 11 and a return port 12. Fuel flows from the fuel tank 2 through the fuel supply pipe 9 and the first control valve 3 to the inlet 11 of the fuel injection pump 1; this line is called the inlet line. Fuel flows out from the return port 12 of the fuel injection pump 1, passes through the second control valve 4, and flows back to the fuel tank 2; this line is called the return line. In the inlet line, under the control of the first control valve 3, the fuel can only flow in the following directions: Figure 1 As shown by the upward arrow, fuel cannot flow from the injection pump 1 through the inlet 11 to the fuel tank 2; in the return line, fuel, under the control of the second control valve 4, can only flow in the direction indicated by the arrow. Figure 1 As shown by the downward arrow, fuel cannot flow from the fuel tank 2 through the return port 12 into the fuel injection pump 1.

[0028] Optionally, both the first control valve 3 and the second control valve 4 in this application are one-way valves. When the diesel engine changes from running to stopped, due to the action of the one-way valves, the fuel in the injection pump 1 on the pipeline will not flow back to the fuel tank 2 and the fuel supply pipe 9, and the fuel and air in the fuel supply pipe 9 and the fuel tank on the return pipeline will not flow back to the injection pump 1. This ensures that there is always fuel in the injection pump 1. When the diesel engine restarts, the presence of fuel in the injection pump 1 enables the diesel engine to start quickly, improving the starting efficiency of the diesel engine.

[0029] In this embodiment, by installing a first control valve 3 on the fuel inlet line of the fuel injection pump 1 and a second control valve 4 on the fuel return line, air released due to negative pressure in the fuel lines and air in the fuel return line will not flow into the fuel injection pump 1 when the diesel engine is stopped. This ensures that fuel is present in the fuel injection pump 1 for an extended period, reducing the impact of air on the diesel engine's starting process, improving starting efficiency, and enhancing starting performance. Furthermore, preventing air from entering the fuel injection pump 1 reduces the extent of damage caused by air and extends its service life.

[0030] Optionally, a fuel filter 6 is also installed on the fuel inlet line of this diesel engine fuel system. The fuel filter 6 is located between the first control valve 3 and the fuel tank 2. The fuel filter 6 is used to filter the fuel, removing impurities from it. In reality, when the fuel flows out of the fuel tank 2, there may be some solid residue. This solid residue may cause blockage of the fuel injection pump 1 and the fuel injector 5, leading to fuel line failure. Therefore, by passing this solid residue along with the fuel through the fuel filter 6, the solid residue will remain in the fuel filter 6, achieving the effect of fuel filtration and reducing the probability of fuel system failure.

[0031] Optionally, the fuel filter 6 is provided with a vent plug 61, which is used to block the vent hole on the fuel filter 6. When air needs to be vented through this vent hole, the vent plug 61 is opened to allow air to escape. When air does not need to be vented, the vent plug 61 blocks the vent hole to prevent dust from entering the fuel filter 6 through the vent hole. That is, air is vented when the vent plug 61 is loose, and air is not vented and dust is prevented when it is tightened.

[0032] In this embodiment, the fuel filter 6 filters the fuel, which can prevent solid residues from clogging the pipeline and ensure the normal operation of the diesel engine. Secondly, the fuel filter 6 is provided with an exhaust plug 61, which can reduce the entry of dust and other impurities into the fuel filter 6 from the exhaust hole, thereby improving the cleanliness of the fuel filter 6.

[0033] Optionally, a fuel distributor 8 is also provided on the return line of the diesel engine fuel system. The fuel distributor 8 is located behind the return port 12 of the injection pump 1 and is connected to the return port 12 of the injection pump 1 through the fuel supply line 9. The fuel distributor 8 is used to store fuel and isolate air intake. In fact, fuel is always present in the fuel distributor 8, so that the air in the fuel tank 2 and the fuel supply line 9 on the return line cannot pass through the fuel distributor 8, so the air cannot reach the injection pump 1, which can better isolate the air.

[0034] Optionally, the opening pressure range of the first control valve 3 and the second control valve 4 is 0-15 kPa. In actual use, it can be set according to the working requirements of the fuel injection pump 1. For example, it can be 5 kPa. That is, when the fuel is flowing, if the pressure generated by the fuel on the first control valve 3 or the second control valve 4 is greater than 5 kPa, the first control valve 3 or the second control valve 4 will open. This application does not limit the specific opening pressure value set for the first control valve 3 and the second control valve 4.

[0035] Optionally, the diesel engine fuel system provided in this application is further equipped with a fuel transfer pump 7, which is located between the fuel tank 2 and the fuel filter 6. The fuel transfer pump 7 can accelerate the fuel transport rate. In practice, the fuel transfer pump 7 pumps fuel out of the fuel tank 2. At this time, the pumped fuel has a certain rate and can pass through the fuel filter 6 and the first control valve 3 relatively quickly, and finally reach the fuel injection pump 1.

[0036] Optionally, the fuel pump 7 used in this application is an electronic fuel pump. The electronic fuel pump automatically starts working when the diesel engine is started and automatically expels air. In practice, the electronic fuel pump can accelerate the expulsion of air from the fuel line, eliminating the need for manual air venting and improving the user's experience with the diesel engine.

[0037] It should be noted that the oil pump 7 provided in this application is an electronic oil pump. In practice, the oil pump 7 can also be a manual oil pump, a pneumatic oil pump, etc. This application does not limit the specific type of oil pump 7 used.

[0038] In this embodiment, the fuel pump 7 is set between the fuel tank 2 and the fuel filter 6, which can accelerate the flow rate of fuel. When air is vented, it can quickly expel the air in the fuel line, increase the air venting rate, and thus accelerate the arrival of fuel without air into the fuel injection pump 1, thereby accelerating the start-up rate of the diesel engine.

[0039] Optionally, the first control valve 3 and the second control valve 4 can be installed separately in the pipeline or integrated into a specific component. For example, the first control valve 3 can be integrated into the inlet of the fuel injection pump 1 or into the fuel filter 6; the second control valve 4 can be integrated into the return port of the fuel injection pump 1.

[0040] It should be noted that when the second control valve 4 is installed separately on the return oil line, the second control valve 4 can be installed on the line between the fuel injection pump 1 and the fuel distributor 8, or on the fuel supply line 9 between the fuel distributor 8 and the fuel tank 2. The specific installation location is not limited here.

[0041] In this invention, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to describe the relative positional relationship between the components or parts and do not specifically limit the specific installation orientation of each component or part.

[0042] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0043] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0044] Furthermore, the structures, proportions, sizes, etc., drawn in the accompanying drawings of this application are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modification to the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects and purposes that this application can produce, should still fall within the scope of the technical content disclosed in this application.

Claims

1. A diesel engine fuel system, characterized in that, include: Fuel tank, fuel injection pump, first control valve, second control valve, and fuel injector; The fuel tank is connected to the fuel injection pump's inlet and outlet via fuel lines. The fuel injection pump provides fuel at a preset pressure. The fuel injector is connected to the fuel injection pump and injects the fuel supplied by the fuel injection pump into the cylinder. The first control valve is located in front of the fuel injection pump's inlet and controls the opening and closing of the fuel injection pump's inlet. The second control valve is located behind the fuel injection pump's outlet and controls the opening and closing of the fuel injection pump's outlet. Both the first control valve and the second control valve are one-way valves; The opening pressure range of the first control valve and the second control valve is 0-15 kPa.

2. The diesel engine fuel system according to claim 1, characterized in that, The diesel engine fuel system also includes a fuel filter; The fuel filter is located between the fuel tank and the first control valve, and the fuel filter is used to filter impurities in the fuel.

3. The diesel engine fuel system according to claim 2, characterized in that, The fuel filter is equipped with a vent plug, which is used to remove air from the fuel line when loosened.

4. The diesel engine fuel system according to claim 2, characterized in that, The first control valve is integrated in the fuel filter or the fuel injection pump.

5. The diesel engine fuel system according to any one of claims 1 to 4, characterized in that, The diesel engine fuel system also includes a fuel distributor; The fuel distributor is located between the fuel injection pump return port and the fuel tank, and the fuel distributor is used to store fuel and isolate air intake.

6. The diesel engine fuel system according to any one of claims 1 to 4, characterized in that, The second control valve is integrated into the return port of the fuel injection pump.

7. The diesel engine fuel system according to any one of claims 1 to 4, characterized in that, The diesel engine fuel system also includes a fuel pump; The fuel pump is located between the fuel tank and the first control valve, and the fuel pump is used to increase the fuel flow rate.

8. The diesel engine fuel system according to claim 7, characterized in that, The oil pump is an electronic oil pump.

Images