Fuel supply device for internal combustion engine

Abstract

To provide a fuel supply device for an internal combustion engine that can exert a fuel efficiency improvement effect.SOLUTION: A fuel supply device 10 for an internal combustion engine 1 supplies a liquid fuel in a fuel tank 20 to the internal combustion engine 1 by a fuel pump 40. The fuel supply device 10 comprises an UFB supply device 50 constituted so as to supply ultra fine bubbles to the liquid fuel, a measuring device 60 for measuring the UFB density of the liquid fuel, and an electrode 70 provided near a fuel suction port 42 of the fuel pump 40. The fuel supply device 10 for the internal combustion engine 1 executes a process for energizing the electrode 70 when the UFB density of the liquid fuel is less than a threshold value.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to a fuel supply device for an internal combustion engine.

Background Art

[0002] A fuel supply device for an internal combustion engine that supplies gas to liquid fuel in a fuel tank is known. An example of the gas is ultra-fine bubbles (UFB). Patent Document 1 exemplifies a fuel supply device for an internal combustion engine provided with a UFB generator. Improvement in fuel consumption is expected in the internal combustion engine by including UFB in the liquid fuel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when the supply of UFB by the UFB generator is stopped, the UFB density of the liquid fuel decreases over time. When the UFB density of the liquid fuel decreases, the effect of improving fuel consumption by UFB decreases.

Means for Solving the Problems

[0005] A fuel supply device for an internal combustion engine for solving the above problems is a fuel supply device for an internal combustion engine that supplies liquid fuel in a fuel tank to the internal combustion engine by a fuel pump, and includes a UFB supply device configured to supply UFB to the liquid fuel, a measuring device that measures the UFB density of the liquid fuel, and an electrode provided near a fuel suction port of the fuel pump. When the UFB density of the liquid fuel is less than a threshold value, a process of energizing the electrode is executed.

Effects of the Invention

[0006] Since the UFBs in the liquid fuel are negatively charged, when an electric current is passed through the electrodes, the UFBs in the liquid fuel gather around the electrodes. Since the electrodes are provided near the fuel inlet of the fuel pump, the UFB density of the liquid fuel existing around the fuel inlet of the fuel pump becomes higher compared to the UFB density of the liquid fuel existing outside the surroundings. The fuel supply device energizes the electrodes when the UFB density in the liquid fuel is less than the threshold value. Accordingly, the UFB density of the liquid fuel supplied to the internal combustion engine becomes high. As a result, the effect of improving the fuel consumption by the UFBs can be exhibited.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0008] Hereinafter, an embodiment of a fuel supply device for an internal combustion engine will be described with reference to FIGS. 1 and 2. Referring to FIG. 1. The internal combustion engine 1 is an internal combustion engine that uses liquid fuel. The internal combustion engine 1 includes a cylinder head 2. An intake port 3 is provided in the cylinder head 2. The intake port 3 introduces intake air into the combustion chamber. The intake port 3 is connected to an air cleaner 5 via an intake supply pipe 4. A throttle valve 6 is disposed in the intake supply pipe 4.

[0009] The fuel supply device 10 supplies liquid fuel to the internal combustion engine 1. The fuel supply device 10 includes a fuel tank 20, a mixed gas section 30, and a fuel pump 40. The fuel supply device 10 supplies the liquid fuel in the fuel tank 20 to the internal combustion engine 1 by the fuel pump 40.

[0010] The fuel tank 20 is configured to store liquid fuel in its internal space. Liquid fuel is supplied to the internal space of the fuel tank 20 through a fuel supply pipe 22 that reaches a fuel filler port 21. Below the internal space of the fuel tank 20, a liquid region LA occupied by the liquid fuel is formed. Above the internal space of the fuel tank 20, a gas region GA occupied by vapor fuel and air is formed.

[0011] The mixed gas section 30 is configured to be filled with a mixed gas containing vapor fuel and air. In one example, the mixed gas section 30 is disposed outside the fuel tank 20. The mixed gas section 30 includes a breather pipe 31 that connects the gas region GA in the fuel tank 20 and the fuel supply pipe 22 to each other. In one example, the mixed gas section 30 is disposed in the gas region GA in the fuel tank 20.

[0012] The internal space of the mixed gas section 30 is filled with the mixed gas. The internal space of the mixed gas section 30 is composed of the internal space of the breather pipe 31. The mixed gas section 30 may be composed of the internal space of a canister (not shown) in addition to the internal space of the breather pipe 31. In this case, the internal space of the canister as the mixed gas section 30 is filled with the mixed gas by being connected to the gas region GA of the fuel tank 20.

[0013] The fuel pump 40 supplies the liquid fuel in the fuel tank 20 to the internal combustion engine 1. The fuel pump 40 includes a main body 41, a fuel suction port 42, and a fuel discharge port 43. In one example, the main body 41 is housed in the internal space of the fuel tank 20. In one example, the main body 41 is disposed outside the fuel tank 20. The fuel suction port 42 is connected to the main body 41. The fuel suction port 42 is disposed in the liquid region LA in the fuel tank 20. The fuel discharge port 43 is connected to the main body 41. The fuel discharge port 43 communicates with a fuel injection valve 46 through a fuel supply pipe 44 and a common rail 45 in sequence. The liquid fuel in the fuel tank 20 sucked from the fuel suction port 42 is discharged from the fuel discharge port 43 through the main body 41. The fuel discharged from the fuel discharge port 43 is sent to the fuel injection valve 46 through the fuel supply pipe 44 and the common rail 45 in sequence.

[0014] The fuel injection valve 46 is attached to the cylinder head 2 of the internal combustion engine 1. The fuel injection valve 46 is configured to inject the liquid fuel sent from the fuel pump 40. In one example, the fuel injection valve 46 injects the liquid fuel into the intake port 3 of the internal combustion engine 1. In one example, the fuel injection valve 46 injects the liquid fuel into the combustion chamber of the cylinder head 2.

[0015] The fuel supply device 10 includes an ultra-fine bubble (UFB) supply device 50, a measuring device 60, and an electrode 70. The UFB supply device 50 is configured to supply UFB to the liquid fuel. The UFB is a bubble having a diameter of less than 1 μm (ISO 20298-1). In the present disclosure, the liquid fuel containing UFB means a liquid fuel in which the diameter distribution of the bubbles contained in the liquid fuel peaks at a bubble diameter of less than 1 μm. Examples of methods for generating UFB include an ultrasonic method, a swirling flow method, a pressure dissolution method, and a micropore method. The UFB supply device 50 includes a main body 51, a fuel inlet 52, a gas inlet 53, and a fuel outlet 54.

[0016] In one example, the main body 51 is housed in the internal space of the fuel tank 20. In one example, the main body 51 is disposed outside the fuel tank 20. The fuel inlet 52 is connected to the main body 51. The fuel inlet 52 is disposed in the liquid region LA in the fuel tank 20. The gas inlet 53 is connected to the main body 51. In one example, the gas inlet 53 communicates with the internal space of the mixed gas section 30 via the gas supply pipe 55. In one example, the gas inlet 53 is disposed in the gas region GA in the fuel tank 20. The fuel outlet 54 is connected to the main body 51. The fuel outlet 54 is disposed in the internal space of the fuel tank 20.

[0017] The UFB supply device 50 is configured to be able to switch the power on and off. When the power of the UFB supply device 50 is on, the UFB supply device 50 generates liquid fuel containing UFB in the main body 51 from the liquid fuel inhaled from the fuel inlet 52 and the mixed gas inhaled from the gas inlet 53. The UFB supply device 50 discharges the generated liquid fuel containing UFB from the fuel discharge port 54 into the internal space of the fuel tank 20. When the liquid fuel containing UFB is discharged from the fuel discharge port 54, the UFB density of the liquid fuel in the fuel tank 20 increases. In the present disclosure, the UFB density is calculated as the number of UFBs contained in a predetermined volume of liquid fuel.

[0018] Since the diameter of the bubbles of UFB is extremely small, UFB is hardly affected by buoyancy in the liquid. For this reason, UFB can exist in the liquid for a long time. When the liquid fuel contains UFB, the combustion of the liquid fuel is promoted by effects such as atomization of the liquid fuel and introduction of oxygen into the liquid fuel, so that effects such as improvement in fuel consumption and improvement in exhaust performance of the internal combustion engine 1 can be expected.

[0019] The average UFB density of the liquid fuel in the fuel tank 20 changes over time. In one example, the UFB density increases while the UFB supply device 50 is operating and decreases over time while the UFB supply device 50 is not operating. In one example, the UFB density decreases when the liquid fuel in the fuel tank 20 increases due to refueling.

[0020] The measuring device 60 is configured to measure the UFB density of the liquid fuel in the fuel tank 20. The measuring device 60 outputs a signal regarding the measured UFB density. In one example, the measuring device 60 measures the UFB density of the liquid fuel in the fuel tank 20 by a method such as the quantitative laser diffraction / scattering method or the particle activation analysis method. In one example, the measuring device 60 calculates the UFB density of the liquid fuel in the fuel tank 20 from the operating time and the stop time of the UFB supply device 50. In one example, the measuring device 60 calculates the UFB density of the liquid fuel in the fuel tank 20 from the amount of change in the volume of the liquid fuel in the fuel tank 20 over time.

[0021] When the measuring device 60 measures the UFB density of the liquid fuel in the fuel tank 20, in one example, the measuring device 60 is configured to measure the UFB density of the liquid fuel in the vicinity of the fuel inlet 42 of the fuel pump 40. The measuring device 60 measures the UFB density in the liquid fuel sucked into the fuel inlet 42 of the fuel pump 40.

[0022] The electrode 70 is disposed in the liquid region LA in the fuel tank 20. The electrode 70 is provided in the vicinity of the fuel inlet 42 of the fuel pump 40. The distance between the fuel inlet 42 and the electrode 70 is shorter than the distance between the fuel outlet 54 and the electrode 70. In the fuel tank 20, the liquid fuel is sucked into the fuel inlet 42 after contacting the electrode 70. The electrode 70 is configured as an anode. Since the UFB is negatively charged, the UFB density of the liquid fuel sucked into the fuel inlet 42 increases when the electrode 70 is energized.

[0023] The fuel supply device 10 includes a detection device 80. The detection device 80 detects the startability of the internal combustion engine 1. The startability indicates a sign that the internal combustion engine 1 starts. In one example, the internal combustion engine 1 is configured as a power source of an automobile. In one example, the detection device 80 is a door sensor that detects the opening and closing of the door of the automobile. The door sensor outputs a signal indicating that there is startability when the door is opened. In one example, the detection device 80 is a seating sensor that detects that a passenger has seated on the seat of the automobile. The seating sensor outputs a signal indicating that there is startability when the passenger has seated on the seat. In one example, when the automobile is a hybrid vehicle, a plug-in hybrid vehicle, etc., the detection device 80 is a battery sensor that detects that the battery charge has decreased. The battery sensor outputs a signal indicating that there is startability when the battery charge has decreased.

[0024] The fuel supply device 10 includes a control device 90. The control device 90 performs various controls based on the UFB density measured by the measuring device 60 and the startability detected by the detection device 80. The control device 90 includes a CPU 91 and a memory 92. By the CPU 91 executing the program stored in the memory 92, various controls are performed in the control device 90.

[0025] In one example, the control device 90 controls the UFB supply device 50. In one example, the control device 90 is configured to operate the UFB supply device 50 when the internal combustion engine 1 is running. In one example, the control device 90 is configured not to operate the UFB supply device 50 when the internal combustion engine 1 is not running. The control device 90 determines the driving state of the internal combustion engine 1 based on the startability detected by the detection device 80.

[0026] In one example, the control device 90 controls the electrode 70. When there is a possibility of starting the internal combustion engine 1, the control device 90 energizes the electrode 70 when the UFB density measured by the measuring device 60 in the liquid fuel is less than the threshold value. The threshold value is set to a value corresponding to the UFB density at which effects such as improvement in fuel consumption and exhaust performance of the internal combustion engine 1 can be obtained due to the inclusion of UFB in the liquid fuel. That is, if the average UFB density of the liquid fuel is less than the threshold value, there is a risk that effects such as improvement in fuel consumption and exhaust improvement of the internal combustion engine 1 will decrease. When the electrode 70 is energized, even if the average UFB density of the liquid fuel is less than the threshold value, the UFB density of the liquid fuel sucked into the fuel inlet 42 increases.

[0027] Referring to FIG. 2. The fuel supply device 10 executes a process of energizing the electrode 70 when the average UFB density of the liquid fuel in the fuel tank 20 is less than the threshold value. The procedure of the process executed by the control device 90 will be described. The control device 90 repeats the process shown in FIG. 2 at regular intervals.

[0028] The control device 90 determines the presence or absence of startability based on the signal output from the detection device 80 (S100). When there is startability (S100: YES), the control device 90 turns on the power of the UFB supply device 50 (S110). When there is no startability (S100: NO), the control device 90 ends the process of FIG. 2.

[0029] After turning on the power of the UFB supply device 50, the control device 90 acquires the UFB density of the liquid fuel based on the output of the measuring device 60 (S120). The control device 90 determines whether the acquired UFB density of the liquid fuel is equal to or greater than the threshold value (S130). When the UFB density is equal to or greater than the threshold value (S130: YES), the control device 90 ends the process of FIG. 2.

[0030] When the UFB density is less than the threshold value (S130: NO), the control device 90 energizes the electrode 70 (S140). After energizing the electrode 70, the control device 90 determines whether the UFB density is equal to or greater than the threshold value (S150). When the UFB density is still less than the threshold value after energizing the electrode 70 (S150: NO), the control device 90 repeats the process of S150 until the UFB density becomes equal to or greater than the threshold value. When the UFB density is equal to or greater than the threshold value (S150: YES), the control device 90 stops energizing the electrode 70 (S160) and then ends the process of FIG. 2.

[0031] The operation and effects of this embodiment will be described. (1) When the UFB density of the liquid fuel is less than the threshold value, the fuel supply device 10 executes a process of energizing the electrode 70. Since the UFB in the liquid fuel is negatively charged, when the electrode 70 is energized, the UFB in the liquid fuel gathers around the electrode 70. Since the electrode 70 is provided near the fuel inlet 42 of the fuel pump 40, the UFB density of the liquid fuel existing around the fuel inlet 42 of the fuel pump 40 becomes higher compared to the UFB density of the liquid fuel existing outside the surroundings. The fuel supply device 10 energizes the electrode 70 when the UFB density of the liquid fuel is less than the threshold value. Therefore, the UFB density of the liquid fuel supplied to the internal combustion engine 1 becomes higher. As a result, the effect of improving fuel consumption by UFB can be exhibited.

[0032] (2) When the internal combustion engine 1 is not running, the power supply of the UFB supply device 50 is turned off, so the UFB density of the liquid fuel decreases. Therefore, at the start of the internal combustion engine 1, the average UFB density of the liquid fuel tends to be low. The fuel supply device 10 executes a process of energizing the electrode 70 when there is a possibility of starting the internal combustion engine 1 and the average UFB density of the liquid fuel is less than the threshold value. As a result, the startability of the internal combustion engine 1 is improved, such as shortening the start time.

Explanation of Signs

[0033] 1... Internal combustion engine, 10... Fuel supply device, 20... Fuel tank, 40... Fuel pump, 42... Fuel suction port, 50... UFB supply device, 60... Measuring device, 70... Electrode.

Claims

【Claim 1】 A fuel supply device for an internal combustion engine that supplies liquid fuel in a fuel tank to the internal combustion engine by a fuel pump, a UFB supply device configured to supply ultra-fine bubbles to the liquid fuel, a measuring device that measures the UFB density of the liquid fuel, and an electrode provided near a fuel suction port of the fuel pump, and performs a process of energizing the electrode when the UFB density of the liquid fuel is less than a threshold value Fuel supply device for an internal combustion engine.

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