Furl supply system

Abstract

To provide a fuel supply system capable of suppressing an increase in a temperature of fuel.SOLUTION: A fuel supply system includes: a first fuel injection valve provided in a cylinder of an internal combustion engine; a second fuel injection valve provided in the cylinder; a first delivery pipe for supplying fuel to the first fuel injection valve; a second delivery pipe for supplying fuel to the second fuel injection valve; and a fuel passage connected to a position downstream of a portion connected to the first fuel injection valve of the first delivery pipe and the second delivery pipe.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fuel supply system. [Background technology]

[0002] A fuel supply system having two fuel injection valves for one cylinder has been developed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-126024 Summary of the Invention [Problem to be solved by the invention]

[0004] One fuel injector injects fuel for ignition. The other fuel injector injects a larger amount of fuel. Two delivery pipes are provided to accommodate the two types of fuel injectors. Fuel that accumulates in the delivery pipe is heated by the heat of the internal combustion engine. As the fuel temperature rises, the cooling effect of fuel injection is reduced. Therefore, the objective of this invention is to provide a fuel supply system that can suppress the rise in fuel temperature. [Means for solving the problem]

[0005] The above object can be achieved by a fuel supply system comprising: a first fuel injection valve provided in a cylinder of an internal combustion engine, a second fuel injection valve provided in the cylinder, a first delivery pipe that supplies fuel to the first fuel injection valve, a second delivery pipe that supplies fuel to the second fuel injection valve, and a fuel passage connected to a position downstream of a portion of the first delivery pipe that is connected to the first fuel injection valve and the second delivery pipe. Effect of the Invention

[0006] A fuel supply system capable of suppressing an increase in fuel temperature can be provided. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram illustrating a fuel supply system according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram illustrating a fuel supply system according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the fuel supply system of the present embodiment will be described with reference to the drawings. However, in the drawings, the dimensions, ratios, etc. of each part may not be illustrated to be completely consistent with the actual ones. Also, in some drawings, some details may be omitted.

[0009] <Embodiment> 1 is a schematic diagram illustrating a fuel supply system 100 according to an embodiment. The fuel supply system 100 supplies fuel to an internal combustion engine 10. The fuel may be gasoline, diesel, ethanol, synthetic fuel, or the like. The fuel supply system 100 has a fuel pump 20, fuel passages 22 and 34, a delivery pipe 24 (first delivery pipe), fuel injection valves 26a to 26d (first fuel injection valves), a delivery pipe 30 (second delivery pipe), and fuel injection valves 32a to 32d (second fuel injection valves).

[0010] The internal combustion engine 10 may be, for example, a diesel engine or a gasoline engine. The internal combustion engine 10 may be, for example, a multi-cylinder in-line engine, and may have four cylinders, the cylinders being 12, 14, 16 and 18, in that order.

[0011] One end of the fuel passage 22 is connected to the fuel pump 20, and the other end is connected to one end of the delivery pipe 24. One end of the fuel passage 34 is connected to the other end of the delivery pipe 24, and the other end of the fuel passage 34 is connected to one end of the delivery pipe 30.

[0012] Of the delivery pipe 24, the portion connected to the fuel passage 22 is the most upstream side. Of the delivery pipe 24, the portion connected to the fuel passage 34 is the most downstream side. Of the delivery pipe 30, the portion connected to the fuel passage 34 is the most upstream side.

[0013] Fuel injection valves 26a, 26b, 26c, and 26d are connected to delivery pipe 24. Fuel injection valves 26a, 26b, 26c, and 26d are arranged in this order from upstream to downstream. Fuel injection valves 32a, 32b, 32c, and 32d are connected to delivery pipe 30. Fuel injection valves 32d, 32c, 32b, and 32a are arranged in this order from upstream to downstream.

[0014] Fuel injectors 26a and 32a are provided in cylinder 12 and inject fuel into cylinder 12. Fuel injectors 26b and 32b are provided in cylinder 14 and inject fuel into cylinder 14. Fuel injectors 26c and 32c are provided in cylinder 16 and inject fuel into cylinder 16. Fuel injectors 26d and 32d are provided in cylinder 18 and inject fuel into cylinder 18.

[0015] The ECU 40 includes a calculation device such as a central processing unit (CPU) and storage devices such as a random access memory (RAM) and a read only memory (ROM). The ECU 40 controls the fuel pump 20.

[0016] Fuel pump 20 pumps up fuel from a fuel tank (not shown). The fuel is supplied to delivery pipe 24 through fuel passage 22 and injected from fuel injection valves 26a, 26b, 26c, and 26d. Fuel is supplied to delivery pipe 30 from delivery pipe 24 through fuel passage 34 and injected from fuel injection valves 32d, 32c, 32b, and 32a.

[0017] The fuel injectors 26a, 26b, 26c, and 26d inject fuel for ignition. The fuel injectors 32d, 32c, 32b, and 32a perform the main spray. The injection amount from the fuel injectors 26a, 26b, 26c, and 26d is less than the injection amount from the fuel injectors 32d, 32c, 32b, and 32a. A mixture of fuel and air is generated in the cylinder. The mixture is burned to generate power. Supplying fuel from two fuel injectors to one cylinder improves ignition performance in a lean state.

[0018] (Comparative Example) 2 is a schematic diagram illustrating a fuel supply system 110 according to a comparative example. The fuel passage 34 is not provided. The fuel passage 42 branches off from the fuel passage 22 midway and is connected to the delivery pipe 30 near the fuel injection valve 32a. Fuel is supplied to the delivery pipe 24 through the fuel passage 22, and is supplied to the delivery pipe 30 through the fuel passage 42.

[0019] The two delivery pipes 24 and 30 are connected in parallel. Fuel tends to accumulate in the delivery pipes. In particular, the amount of fuel consumed in the delivery pipe 24 is less than the amount consumed in the delivery pipe 30. A large amount of fuel remains in the delivery pipe 24. The temperature of the fuel remaining in the delivery pipe 24 rises due to heat transmitted from the internal combustion engine 10. The cooling effect of the fuel is reduced, and deposits tend to accumulate on the fuel injection valves 26a to 26d.

[0020] According to this embodiment, as shown in FIG. 1, the fuel passage 34 is connected to the delivery pipe 24 and the delivery pipe 30. The fuel pump 20, the fuel passage 22, the delivery pipe 24, the fuel passage 34, and the delivery pipe 30 are connected in series, and the fuel flows in the above order. The fuel is supplied to the delivery pipe 24 through the fuel passage 22, and is discharged from the delivery pipe 24 through the fuel passage 34. Since the replacement of the fuel in the delivery pipe 24 is promoted, the fuel is less likely to stagnate. The temperature rise of the fuel can be suppressed. Since a cooling effect is obtained, the temperature of the fuel injection valves 26a, 26b, 26c, and 26d is less likely to rise, and the occurrence of deposits is suppressed.

[0021] 1, the fuel passage 34 is connected to the delivery pipe 24 at a position downstream of a portion where the four fuel injection valves 26a, 26b, 26c, and 26d are connected. The fuel passage 34 may be connected downstream of at least one of the fuel injection valves 26a to 26d. The fuel passage 34 is connected downstream of a position where the delivery pipe 24 is connected to the fuel passage 22.

[0022] 1, the fuel passage 34 may be connected to an end of the delivery pipe 24 in the direction in which the fuel injection valves are arranged. The fuel passage 34 may be connected to a position in the delivery pipe 24 between the fuel injection valves.

[0023] The number of fuel injection valves provided in one delivery pipe may be four or less, or may be four or more.

[0024] Although a preferred embodiment of the present invention has been described in detail above, the present invention is not limited to such a specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0025] 10 internal combustion engine, 12, 14, 16, 18 cylinder, 20 fuel pump, 24, 30 delivery pipe, 26a to 26d, 32a to 32d fuel injector, 22, 34, 42 fuel passage, 40 ECU, 100, 110 fuel supply system

Claims

[Claim 1] a first fuel injection valve provided in a cylinder of the internal combustion engine; A second fuel injection valve provided in the cylinder; a first delivery pipe that supplies fuel to the first fuel injection valve; a second delivery pipe that supplies fuel to the second fuel injection valve; a fuel passage connected to the second delivery pipe and located downstream of a portion of the first delivery pipe connected to the first fuel injection valve;

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