JP2016065502A - Fuel supply apparatus and fuel supply apparatus control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel supply apparatus capable of realizing the atomization, wide diffusion, and low penetration of fuel spray injected and supplied to an internal combustion engine.SOLUTION: A fuel supply apparatus 1 for an internal combustion engine pressurizes fuel pumped up from a fuel tank 2 by a fuel pressurization pump 3 and injects the fuel to the internal combustion engine from an injector 10. A needle valve of the injector 10 and a nozzle main body acting as electrodes charge the fuel injected from the injector 10. A fuel physical property sensor 23 detects permittivity or electric conductivity of the fuel. An additive agent stored in an additive agent supply passage 41 is supplied by the additive agent supply passage 41 to the fuel flowing in a fuel route. An ECU 30 adjusts the quantity of the additive agent mixed with the fuel on the basis of the permittivity and electric conductivity detected by the fuel physical property sensor 23. The ECU 30 can thereby increase a charge amount of the fuel injected from the injector 10 at high pressure.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fuel supply device that supplies fuel to an internal combustion engine and a control method thereof.

Conventionally, the fuel supplied to the internal combustion engine is charged, and the surface of the charged fuel is sheared by the charge of the charged charge, or the repulsive force acts on the atomized particles to spray the fuel. A fuel supply device for atomizing is known.
The fuel supply device described in Patent Document 1 forms a vortex in the fuel flowing through the injection nozzle that injects the fuel, and quickly separates the fuel injected from the nozzle orifice from the injection nozzle. Thereby, it is suppressed that the electric charge attached to the fuel is discharged to the outer wall of the injection nozzle. Therefore, the fuel injected from the injector is maintained in a charged state, and atomization by electrostatic force is promoted.

JP-A-4-325770

However, in general, the upper limit value of the charge amount of the fuel is determined by the dielectric constant and electric conductivity of the fuel. For this reason, in the fuel supply device described in Patent Document 1, if the dielectric constant of the fuel is large and the electrical conductivity is small, it is difficult to increase the charge amount of the fuel injected at high pressure. Further, when the fuel injected from the injector becomes high pressure and the flow rate of the fuel flowing through the injector increases, the time for the fuel to pass between the electrodes forming the electric field is shortened, so that it becomes difficult to sufficiently charge the fuel. .
As a result, when the penetration force (penetration) increases without the fuel spray injected into the internal combustion engine spreading widely, combustion worsens and carbon monoxide (CO), hydrocarbons (HC), particulate matter ( There is a risk that the amount of emissions such as Particulate Matter) will increase.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a fuel supply device capable of realizing atomization / wide diffusion and low penetration of fuel spray injected and supplied to an internal combustion engine, and a control method thereof. And

  The fuel supply device for an internal combustion engine according to the first invention pressurizes the fuel pumped up from the fuel tank by a fuel pressurizing pump and sprays the fuel from the injector onto the internal combustion engine. The charging means charges the fuel injected from the injector. The fuel property sensor detects the dielectric constant or electric conductivity of the fuel flowing through the fuel path from the fuel tank to the injector. The additive mixing means mixes the fuel flowing through the fuel path with an additive that changes the dielectric constant and electrical conductivity of the fuel. The control means adjusts the amount of the additive mixed with the fuel by the additive mixing means based on the dielectric constant and electric conductivity of the fuel detected by the fuel physical property sensor.

  The relaxation time during which the fuel can be charged varies depending on the dielectric constant and electrical conductivity of the fuel. That is, τ = ε / κ, where τ is relaxation time, ε is dielectric constant, and κ is electrical conductivity. Therefore, the control means shortens the relaxation time for charging the fuel by adjusting the amount of the additive so as to reduce the dielectric constant of the fuel and increase the electric conductivity, and charge the fuel injected at high pressure. It is possible to increase the amount. Therefore, this fuel supply device can atomize and spread the fuel spray injected from the injector to the internal combustion engine by electrostatic force, and can realize low penetration.

The second invention is an invention of a control method of the fuel supply device. This control method sets the amount of additive mixed with the fuel by the additive mixing means based on the dielectric constant or electrical conductivity of the fuel detected by the fuel physical property sensor and the dielectric constant or electrical conductivity of the additive.
Thus, even after the additive is mixed with the fuel, even when the fuel is returned to the fuel tank or the like as surplus fuel, the control means again calculates the amount of the additive to be mixed with the fuel, and the injector It is possible to accurately adjust the dielectric constant and electrical conductivity of the fuel injected from the fuel.

It is a block diagram of the fuel supply apparatus by 1st Embodiment of this invention. It is a principal part enlarged view of the injector with which the fuel supply apparatus by 1st Embodiment is provided. It is a table | surface which shows the difference in the electrical conductivity and relaxation time by refinement | purification of a fuel. It is a table | surface which shows the electrical conductivity and relaxation time of the fuel which mixed the additive. It is a flowchart of electrostatic spray control by a 1st embodiment. It is explanatory drawing of the fuel supply apparatus by 2nd Embodiment. It is a flowchart of electrostatic spray control by 2nd Embodiment. It is explanatory drawing of the fuel supply apparatus by 3rd Embodiment. It is a time chart of the multistage injection by 4th Embodiment. It is a schematic diagram of the fuel spray of the multistage injection by 4th Embodiment. It is a time chart of multistage injection by a 5th embodiment. It is a schematic diagram of the fuel spray of the multistage injection by 5th Embodiment. It is a time chart of multistage injection by a 6th embodiment. It is a schematic diagram of the fuel spray of the multistage injection by 6th Embodiment. It is a time chart of multistage injection by a 7th embodiment. It is a time chart of the multistage injection by 8th Embodiment.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In the description of the plurality of embodiments, substantially the same configuration is denoted by the same reference numeral, and redundant description is omitted.
(First embodiment)
A first embodiment of the present invention is shown in FIGS. The fuel supply device 1 according to the first embodiment supplies fuel to an internal combustion engine such as a deal engine or a gasoline engine (not shown).
First, the configuration of the fuel supply device 1 will be described with reference to FIGS. 1 and 2.
The fuel tank 2 corresponds to the type of the internal combustion engine and stores light oil, gasoline, biofuel, or the like.
The fuel pressurization pump 3 pressurizes the fuel pumped up from the fuel tank 2 via the low pressure fuel pipe 4 and pumps it from the high pressure fuel pipe 5 to the common rail 6. The fuel stored in the common rail 6 is directly injected and supplied to the combustion chamber of the internal combustion engine from the injector 10 connected to the common rail 6 via the connection pipe 61.
Excess fuel discharged from the fuel pressurizing pump 3, the common rail 6, and the injector 10 passes through the first return passage 7, the second return passage 8, and the third return passage 9, respectively, and is returned to the fuel tank 2.

In the additive tank 40, an additive capable of changing the dielectric constant and electric conductivity of the fuel is stored. (A) Biofuel containing aldehyde, alcohol or ketone, (b) Liquid fuel additive containing aldehyde, alcohol or ketone, (c) Ionic liquid containing physical properties of aldehyde, alcohol or ketone, (d Or a solid or gas that becomes an ionic liquid containing the properties of aldehyde, alcohol or ketone after dissolution. These additives can be mixed in a small amount with the fuel to reduce the dielectric constant of the fuel and increase the electrical conductivity.
Additives are also described in JP-A-2006-83391.

An additive supply path 41 is connected between the fuel path through which fuel flows from the fuel tank 2 to the injector 10 and the additive tank 40.
In FIG. 1, a first additive supply path 411 connecting the low pressure fuel pipe 4 and the additive tank 40, a second additive supply path 412 connecting the high pressure fuel pipe 5 and the additive tank 40, and The several 3rd additive supply path 413 which connects the connection pipe 61 and the tank 40 for additives is illustrated. The fuel supply apparatus 1 of the present embodiment only needs to include any one of the first to third additive supply paths 411, 412, and 413, and the additive supply path 41 is The fuel tank 2 to the injector 10 may be connected to any part of the fuel path through which the fuel flows.

  An electromagnetic valve 42 for controlling the flow rate of the additive flowing through the additive supply path 41 is provided in the middle of the additive supply path 41. This makes it possible to accurately adjust the amount of additive supplied to the fuel path. The electromagnetic valve 42 is driven and controlled by an electronic control device (hereinafter referred to as “ECU”) 30 of the vehicle. The ECU 30 corresponds to an example of a “control unit” recited in the claims.

Further, an additive pressurizing pump 43 (see FIG. 6) 43 for pressurizing the additive can be installed in the additive tank 40 or the additive supply path 41. Thereby, even when the fuel pressure flowing through the fuel path is higher than the atmospheric pressure, the additive can be reliably supplied to the fuel.
In addition, when the additive supply path 41 is connected to the fuel tank 2, the additive pressurizing pump 43 may be eliminated.
Further, when the additive supply path 41 is connected to the low-pressure fuel pipe 4 connecting the fuel tank 2 and the fuel pressurizing pump 3, the pressure applied to the additive by the additive pressurizing pump 43 is reduced. Also good.
In the present embodiment, the additive tank 40, the additive supply path 41, the electromagnetic valve 42, and the additive pressurizing pump 43 correspond to an example of “additive mixing means” described in the claims.

As shown in FIG. 2, the injector 10 includes a nozzle body 11 and a needle valve 12 provided so as to be capable of reciprocating in the axial direction inside the nozzle body 11. The nozzle body 11 is formed in a bottomed cylindrical shape, and has a fuel passage 13 inside. A valve seat 14 on which the needle valve 12 can be seated and separated is formed on the inner wall of the nozzle body 11. The nozzle body 11 has an injection hole 15 downstream of the valve seat 14.
When the needle valve 12 is separated from the valve seat 14, fuel is injected from the injection hole 15. On the other hand, when the needle valve 12 is seated on the valve seat 14, the fuel injection from the nozzle hole 15 is stopped.

In the injector 10 of this embodiment, the needle valve 12 is electrically connected to the anode of the booster circuit 20, and the nozzle body 11 is electrically connected to the ground. The injector 10 may be configured such that the nozzle body 11 is electrically connected to the anode of the booster circuit 20 and the needle valve 12 is electrically connected to the ground.
The booster circuit 20 boosts the voltage of the battery or the storage battery 22 and gives a potential difference to the needle valve 12 and the nozzle body 11 included in the injector 10. The needle valve 12 and the nozzle body 11 function as an electrode that gives an electric charge to the fuel. Thereby, an electric field is formed in the fuel passage 13 between the needle valve 12 and the nozzle body 11. Therefore, the injector 10 can charge the fuel flowing through the fuel passage 13.
In the present embodiment, the booster circuit 20 and the needle valve 12 and the nozzle body 11 functioning as electrodes correspond to an example of “charging means” described in the claims.

In the present embodiment, the inner wall of the fuel passage 13 or the inner wall of the injection hole 15 positioned downstream of the needle valve 12 and the nozzle body 11 functioning as electrodes are surface-treated with the insulating material 16. . The insulating material 16 suppresses the discharge of electric charges charged in the fuel. Examples of the insulating material 16 include yttria, alumina, quartz, zirconia, silicon nitride, aluminum nitride, cordierite, diamond-like coating (DLC), and intrinsic carbon film coating (ICF). For example, when the areas of the needle valve 12 and the nozzle body 11 that function as electrodes are ensured over a wide range, the places where the surface treatment with the insulating material 16 is performed may be limited. In this case, it is preferable to perform the surface treatment of the insulating material 16 only on the inner wall of the injection hole 15 where the cross-sectional area of the fuel passage 13 is the smallest.
Further, instead of the surface treatment with the insulating material 16, the inner wall of the fuel passage 13 or the inner wall of the injection hole 15 located on the downstream side of the fuel from the needle valve 12 and the nozzle body 11 functioning as electrodes is formed from the insulating material 16. May be.

As shown in FIG. 1, the fuel tank 2 is provided with a fuel property sensor 23. The fuel physical property sensor 23 has a pair of electrodes (not shown) immersed in the fuel, and detects the dielectric constant or electric conductivity of the fuel interposed between the electrodes. The fuel property sensor 23 outputs a signal corresponding to the dielectric constant or electric conductivity of the fuel to the ECU 30.
The fuel property sensor 23 is not limited to the fuel tank 2 and may be provided at any location in the fuel path from the fuel tank 2 to the injector 10. Thereby, the fuel property sensor 23 can detect the dielectric constant or electric conductivity of the fuel flowing through the fuel path from the fuel tank 2 to the injector 10.

  In the ECU 30 of this embodiment, data relating to the specifications of the injector 10 and data relating to basic physical properties of the fuel stored in the fuel tank 2 are stored in advance as map information. The ECU 30 stores the dielectric constant of the fuel as one of data relating to the basic physical properties of the fuel. Therefore, the fuel physical property sensor 23 of the present embodiment only needs to detect only the electric conductivity of the fuel. This is because, in general, in the case of the same kind of fuel, the change in the dielectric constant of the fuel is small compared to the electric conductivity.

On the other hand, as shown in FIG. 3, even if the electric conductivity of the fuel is the same light oil, the electric conductivity varies greatly depending on, for example, the sulfur content. Moreover, when the electric conductivity is different, the relaxation time required for charging the fuel is greatly different.
Therefore, the ECU 30 applies the fuel from the booster circuit 20 to the fuel via the needle valve 12 and the nozzle body 11 based on the dielectric constant of the fuel stored in advance and the electric conductivity detected by the fuel physical property sensor 23. Control voltage and voltage application time.

  Furthermore, as shown in FIG. 4, the electrical conductivity of the fuel is greatly changed by mixing a small amount of additive. As the electrical conductivity increases, the fuel relaxation time is significantly shortened. Therefore, the ECU 30 of the present embodiment adjusts the amount of additive mixed with the fuel based on the dielectric constant of the fuel stored in advance and the electric conductivity detected by the fuel physical property sensor 23. Thereby, even in the multistage injection in which the fuel injection of the injector 10 is performed a plurality of times in one cycle of the internal combustion engine, the ECU 30 can charge the fuel in a short time.

  As shown in FIG. 1, a signal related to the engine speed and a signal related to the accelerator opening are input to the ECU 30 as signals for detecting the operating state of the internal combustion engine. With these signals, the ECU 30 sets the flow rate of the fuel flowing through the injector 10. The ECU 30 can control the voltage applied to the fuel and the voltage application time from the booster circuit 20 via the needle valve 12 and the nozzle body 11 as electrodes based on the flow rate of the fuel.

Next, a method in which the ECU 30 controls the voltage applied to the fuel and the voltage application time will be described based on the flowchart of FIG. In the flowchart, “step” is displayed as “S”.
In this electrostatic spray control, the ECU 30 causes the CPU to execute a program stored in the memory, whereby the addition amount calculating means 31, the target time calculating means 32, the target voltage calculating means 33, the allowable voltage calculating means 34, the voltage setting. It functions as the means 35, the time setting means 36, etc. (refer FIG. 1).

When the electrostatic spray control is started, the ECU 30 detects the electric conductivity of the fuel based on the input signal from the fuel property sensor 23 in step 10.
In step 11, the ECU 30 reads the dielectric constant of the fuel stored in advance in the memory.
In step 12, the ECU 30 detects the flow rate of the fuel flowing through the injector 10 based on the engine speed and the accelerator opening.

  Next, in step 13, the ECU 30 functions as the addition amount calculation means 31, and determines the amount of additive mixed with the fuel from the dielectric constant of the fuel, the electric conductivity of the fuel, and the dielectric constant and electric conductivity of the additive. Calculate and set. Then, the electromagnetic valve 42 provided in the additive supply path 41 is opened in order to mix the set amount of the additive with the fuel. Thus, the additive stored in the additive tank 40 is supplied from the additive supply path 41 to the fuel flowing through the low-pressure fuel pipe 4 and the like.

Subsequently, in step 14, the ECU 30 functions as the target time calculation means 32, and sufficiently charges the fuel based on the flow rate of the fuel flowing through the injector 10, the electric conductivity and the dielectric constant of the fuel mixed with the additive. Calculate the possible target application time.
The target application time is set to a relaxation time τ that can give the fuel the charge necessary for performing desired fuel injection from the injector 10.
The relaxation time τ can be calculated by τ = ε / κ. Here, ε is a dielectric constant, and κ is an electrical conductivity.

  In step 14, the ECU 30 functions as the target voltage calculation means 33, and performs desired fuel injection from the injector 10 based on the flow rate of the fuel flowing through the injector 10, the electrical conductivity and the dielectric constant of the fuel mixed with the additive. A target applied voltage capable of giving the fuel a necessary charge for performing the calculation is calculated. Further, the ECU 30 sets the target applied voltage to a higher value as the flow rate is higher. As the target applied voltage is higher, the charge amount of the fuel can be increased.

  Next, in step 15, the ECU 30 functions as the allowable voltage calculation means 34 and reads the distance between the needle valve 12 that functions as an electrode and the nozzle body 11 from the data related to the specifications of the injector 10. The ECU 30 causes dielectric breakdown between the needle valve 12 functioning as an electrode and the nozzle body 11 from the relationship between the distance between the needle valve 12 and the nozzle body 11 and the electrical conductivity of the fuel mixed with the additive. An allowable applied voltage that can be prevented from occurring is calculated.

  Subsequently, in step 16, the ECU 30 functions as the voltage setting means 35, and the voltage applied to the fuel from the needle valve 12 and the nozzle body 11 functioning as electrodes is set to the lower of the target applied voltage and the allowable applied voltage. Set to voltage. Specifically, when the target applied voltage is lower than the allowable applied voltage (step 16: YES), the process proceeds to step 17. On the other hand, when the allowable applied voltage is equal to or lower than the target applied voltage (step 16: NO), the process proceeds to step 18.

Next, in step 17, the ECU 30 functions as the time setting means 36, and the time from the end of the immediately preceding fuel injection by the injector 10 to the end of the fuel injection and the target application time calculated by the target time calculating means 32. The voltage application time is set to one of the shorter times. The time from the end of the immediately preceding fuel injection by the injector 10 to the end of the fuel injection is referred to as a limit time during which voltage can be applied from the electrode to the fuel.
Specifically, when the target application time is shorter than the limit time (step 17: YES), the process proceeds to step 19. On the other hand, when the limit time is equal to or shorter than the target application time (step 17: NO), the process proceeds to step 20.

  In step 19, the ECU 30 sets the applied voltage V1, the frequency f1, and the pulse width d1. In step 19, the applied voltage V1 is a target applied voltage. The frequency f1 and the pulse width d1 are set such that the total time for applying the voltage to the fuel becomes the target application time.

  In step 20, the ECU 30 sets the applied voltage V1, the frequency f2, and the pulse width d2. In step 20, the applied voltage V1 is a target applied voltage. Further, the frequency and the duty ratio are set so that the total time for applying the voltage to the fuel becomes the limit time or a time close to the limit time for the frequency f2 and the pulse width d2.

  In step 16 described above, when the allowable applied voltage is equal to or lower than the target applied voltage (step 16: NO), the process proceeds to step 18. In step 18, the ECU 30 functions as the time setting means 36 and sets the voltage application time to the shorter one of the target application time and the limit time. Specifically, when the target application time is shorter than the limit time (step 18: YES), the process proceeds to step 21. On the other hand, when the limit time is equal to or shorter than the target application time (step 18: NO), the process proceeds to step 22.

  In step 21, the ECU 30 sets the applied voltage V2, the frequency f1, and the pulse width d1. In step 21, the applied voltage V2 is an allowable applied voltage. The frequency f1 and the pulse width d1 are set such that the total time for applying the voltage to the fuel becomes the target application time.

In step 22, the ECU 30 sets the applied voltage V2, the frequency f2, and the pulse width d2. In step 22, the applied voltage V2 is an allowable applied voltage. Further, the frequency and the duty ratio are set so that the total time for applying the voltage to the fuel becomes the limit time or a time close to the limit time for the frequency f2 and the pulse width d2.
In this manner, the ECU 30 can set the voltage applied to the fuel and the voltage application time.
In the present embodiment, the process of step 10 described above corresponds to an example of the “physical property detection step” recited in the claims, and the process of step 13 described above is described as “addition amount setting” described in the claims. This corresponds to an example of “step”.

(Function and effect)
The fuel supply device 1 of the first embodiment has the following operational effects.
(1) In the first embodiment, the ECU 30 adjusts the amount of additive mixed with the fuel based on the dielectric constant and electric conductivity of the fuel detected by the fuel physical property sensor 23.
The relaxation time during which the fuel can be charged varies depending on the dielectric constant and electrical conductivity of the fuel. Therefore, the control means shortens the relaxation time for charging the fuel by adjusting the amount of the additive so as to reduce the dielectric constant of the fuel and increase the electric conductivity, and charge the fuel injected at high pressure. It is possible to increase the amount. Therefore, the fuel supply device 1 can atomize and spread the fuel spray injected from the injector 10 to the internal combustion engine by electrostatic force, and can realize low penetration.

(2) In the first embodiment, the ECU 30 determines the fuel from the electric conductivity of the fuel detected by the fuel physical property sensor 23 and the dielectric constant of the fuel stored in the ECU 30 and the dielectric constant and electric conductivity of the additive. Calculate the amount of additive to be mixed.
Thus, even after the additive is mixed with the fuel, even if the fuel is returned to the fuel tank 2 or the like as surplus fuel, the ECU 30 again calculates the amount of the additive to be mixed with the fuel, and the injector It is possible to accurately adjust the dielectric constant and electric conductivity of the fuel injected from the fuel cell 10.

(3) In the first embodiment, the ECU 30 stores in advance the dielectric constant of the fuel stored in the fuel tank 2. The fuel property sensor 23 outputs only a signal corresponding to the electrical conductivity to the ECU 30.
In general, in the case of the same type of fuel, the change in the dielectric constant of the fuel is small compared to the electrical conductivity. Therefore, the ECU 30 can adjust the amount of additive mixed with the fuel based on the dielectric constant stored in advance and the electrical conductivity detected by the fuel property sensor 23. Therefore, the fuel supply device 1 can be simplified in configuration by including the fuel physical property sensor 23 that detects only the electric conductivity.

(4) In the first embodiment, the additive supply path 41 can be connected to the low-pressure fuel pipe 4 that connects the fuel tank 2 and the fuel pressurization pump 3.
Thereby, the fuel supply apparatus 1 can mix an additive with a fuel, without giving a pressure to an additive, or giving a small pressure to an additive.

(5) In the first embodiment, as an additive, (a) a biofuel containing aldehyde, alcohol or ketone, (b) a liquid fuel additive containing aldehyde, alcohol or ketone, (c) aldehyde, alcohol or ketone Examples include ionic liquids containing physical properties, (d), or solids or gases that become ionic liquids containing physical properties of aldehyde, alcohol or ketone after dissolution.
By mixing a small amount of these additives into the fuel, the dielectric constant and electrical conductivity of the fuel can be greatly changed.

(6) In the first embodiment, the needle valve 12 functioning as an electrode and the fuel passage 13 or the injection hole 15 located on the downstream side of the fuel from the nozzle body 11 are surface-treated with an insulating material 16.
Further, in the first embodiment, the needle valve 12 functioning as an electrode and the fuel passage 13 or the injection hole 15 located on the downstream side of the fuel from the nozzle body 11 can be formed from the insulating material 16.
As a result, the discharge of charges charged in the fuel is suppressed. Therefore, the fuel supply device 1 can realize atomization / wide diffusion and low penetration of the fuel spray.

(7) In the first embodiment, the ECU 30 controls the voltage applied to the fuel and the voltage application time based on the dielectric constant or electric conductivity of the fuel.
The relaxation time during which the fuel can be charged varies depending on the dielectric constant and electrical conductivity of the fuel. In addition, as the voltage is increased, the charge amount of the fuel can be increased. Therefore, the control means can sufficiently charge the fuel injected at a high pressure by controlling the voltage and the voltage application time based on the dielectric constant or electric conductivity of the fuel.

(8) In the first embodiment, the ECU 30 controls the voltage applied to the fuel and the voltage application time based on the flow rate of the fuel flowing through the injector 10.
As the fuel pressure injected from the injector 10 increases, the flow rate of the fuel flowing through the injector 10 increases, and the time for the fuel to pass between the electrodes decreases. In that case, the ECU 30 can sufficiently charge the fuel by increasing the voltage applied to the fuel or extending the voltage application time.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the additive supply path 41 has one end connected to the additive tank 40 and the other end connected to the injector 10. The additive supply path 41 supplies the additive to the fuel flowing through the fuel passage 13 formed inside the nozzle body 11 included in the injector 10.
The additive supply path 41 is provided with an electromagnetic valve 42 for adjusting the flow rate of the additive flowing through the additive supply path 41. This makes it possible to supply an accurate amount of additive to the fuel flowing through the fuel path.
An additive pressurizing pump 43 for pressurizing the additive is installed in the additive supply path 41. Thus, even when the fuel pressure flowing through the fuel passage 13 inside the injector 10 is several tens to several hundreds of MPa, the additive can be reliably supplied to the fuel.

In the second embodiment, a pair of electrodes 44 and 45 are provided in the additive tank 40. One electrode 44 is electrically connected to the anode of the booster circuit 20, and the other electrode 45 is electrically connected to the ground. As a result, the additive stored in the additive tank 40 can be charged. The electrodes 44 and 45 are not limited to the additive tank 40 and may be provided in the additive supply path 41.
The periphery of the additive supply path 41 is covered with an insulating member 46. Thereby, it is suppressed that the electric charge charged in the fuel is released before reaching the fuel passage 13.
In the second embodiment, the booster circuit 20 and the electrodes 44 and 45 described above correspond to an example of “charging means” recited in the claims.

  Also in the second embodiment, the ECU 30 adjusts the amount of the additive mixed with the fuel based on the flow rate, dielectric constant, and electrical conductivity of the fuel. In this embodiment, the whole fuel is charged by mixing the additive with the fuel.

Next, a method in which the ECU 30 according to the second embodiment controls the voltage applied to the fuel and the voltage application time will be described based on the flowchart of FIG.
In the electrostatic spray control of the second embodiment, steps 10 to 12 are the same as the processing of the first embodiment.
In step 13, the ECU 30 functions as the addition amount calculation means 31, and calculates and sets the amount of additive mixed with the fuel from the fuel flow rate, electrical conductivity, and dielectric constant. At this time, the ECU 30 increases the flow rate of the additive as the flow rate of the fuel flowing through the injector 10 increases. Thereby, the ECU 30 can make the ratio of the additive to the fuel correspond to the target value.

Thereafter, in step 30, the ECU 30 sets a timing for mixing the additive with the fuel. Specifically, the ECU 30 mixes the additive with the fuel in accordance with the timing of fuel injection that requires low penetration and wide diffusion of the fuel spray according to the operating state of the internal combustion engine. Charge.
In addition, in the multistage injection in which the injection is performed a plurality of times in one cycle of the internal combustion engine, the ECU 30 uses the additive as the fuel in accordance with the timing of performing the pre-injection or the main injection that requires low penetration and wide diffusion of fuel spray. It is also possible to mix and charge the fuel.

  Subsequent steps 14 to 22 are substantially the same as the control of the first embodiment. However, the allowable applied voltage in step 15 is a voltage that can prevent dielectric breakdown from occurring when a voltage is applied to the additive.

(Function and effect)
The fuel supply device 1 of the second embodiment has the following operational effects.
(1) In 2nd Embodiment, an additive is mixed with the fuel which flows through the injector 10 from the additive supply path 41 connected to the injector 10. FIG. The ECU 30 sets the time when the additive is mixed with the fuel.
Thereby, in the injection control in which the fuel is intermittently injected from the injector 10, the additive mixed with the fuel injected at the predetermined fuel injection timing affects the fuel injected at the fuel injection timing before and after that. Is prevented. Therefore, it is possible to control the combustion position in the combustion chamber of the internal combustion engine for each fuel spray injected from the injector 10.

(2) In the second embodiment, the ECU 30 adjusts the amount of additive mixed with the fuel based on the flow rate of the fuel flowing through the injector 10.
The ECU 30 can make the ratio of the additive to the fuel correspond to the target value by increasing the flow rate of the additive as the flow rate of the fuel flowing through the injector 10 increases.

(3) In the second embodiment, the electrodes 44 and 45 provided in the additive tank 40 or the additive supply path 41 apply a voltage to the additive.
Thereby, the fuel can be charged in a short time by mixing the precharged additive and the fuel.

(Third embodiment)
A third embodiment of the present invention will be described with reference to FIG. The third embodiment is a combination of the first embodiment and the second embodiment.
In the third embodiment, the additive supply path 41 supplies the additive to the fuel flowing through the fuel passage 13 inside the injector 10. In the third embodiment, the needle valve 12 and the nozzle body 11 included in the injector 10 function as electrodes that give electric charge to the fuel.

  The ECU 30 adjusts the amount of additive mixed with the fuel based on the flow rate of the fuel flowing through the injector 10. Specifically, as the flow rate of the fuel flowing through the injector 10 increases, the time during which the fuel contacts the needle valve 12 functioning as an electrode and the nozzle body 11 is shortened. Increase the amount. As a result, the ECU 30 can shorten the relaxation time for charging the fuel and sufficiently charge the fuel to be injected at high pressure.

(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to FIGS. In the fourth to eighth embodiments described below, in the multistage injection in which the fuel injection of the injector 10 is performed a plurality of times in one cycle of the diesel engine, the timing for applying the voltage to the fuel and the fuel spray formed thereby This state is exemplified.
As shown in FIG. 9A, in the fourth embodiment, the first pre-injection is performed during the time t1-t2, the second pre-injection is performed during the time t4-t6, and the time t8-t10. Main injection is performed during this period.
Further, as shown in FIG. 9B, voltage is applied to the second pre-injection fuel during time t3-t5, and voltage is applied to the main injection fuel during time t7-t9. Is done.

In this case, as shown in FIG. 10A, since the fuel spray for the first pre-injection is not charged, the penetration is high and the combustion chamber 54 is defined by the piston head 51, the cylinder head 52, and the cylinder liner 53. The fuel is injected to the position far from the injector 10.
Next, as shown in FIG. 10B, since the fuel spray for the second pre-injection is charged, it has low penetration and wide diffusion, and fuel is injected close to the injector 10. As a result, an optimal premixed state of fuel spray and air is formed in the combustion chamber 54. In FIG. 10B, the fuel spray injected by the first pre-injection is indicated by a broken line.
Subsequently, as shown in FIG. 10C, since the fuel spray for main injection is charged, it has low penetration and wide diffusion, and ignites and burns. In FIG. 10C, fuel sprays injected by the first pre-injection and the second pre-injection are indicated by broken lines, respectively.

The fuel supply device 1 according to the fourth embodiment has the following effects.
(1) In the fourth embodiment, the ECU 30 controls the voltage applied to the fuel and the voltage application time according to the combustion position of the fuel spray in the combustion chamber 54 of the internal combustion engine.
As a result, the fuel spray can be burned at a desired position in the combustion chamber 54 of the internal combustion engine.

(2) In the fourth embodiment, the ECU 30 controls the voltage applied to the fuel and the voltage application time for each fuel injection in the multi-stage fuel injection.
Thus, the fuel spray can be burned at a desired position in the combustion chamber 54 for each fuel injection.

(Fifth embodiment)
A fifth embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 11A, in the fifth embodiment, the first pre-injection is performed during the time t22-t24, the second pre-injection is performed during the time t25-t26, and the time t28-t30. Main injection is performed during this period.
Further, as shown in FIG. 11B, a voltage is applied to the first pre-injection fuel during time t21-t23, and a voltage is applied to the main injection fuel during time t27-t29. Is done.

In this case, as shown in FIG. 12 (A), the fuel spray for the first pre-injection is charged, so that immediately after the injection, low penetration and wide diffusion are achieved, atomization is promoted, and the central portion of the combustion chamber 54 Entrain air and burn.
Next, as shown in FIG. 12B, since the fuel spray for the second pre-injection is not charged, the penetration becomes high and the air near the wall surface of the combustion chamber 54 is entrained and burned.
Subsequently, as shown in FIG. 12 (C), the fuel spray for main injection is charged, resulting in low penetration and wide diffusion, and effectively using the air near the center and the wall surface of the combustion chamber 54. Burn.
The fuel supply device 1 of the fifth embodiment has the same operational effects as the fourth embodiment.

(Sixth embodiment)
A sixth embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 13A, in the sixth embodiment, pre-injection is performed between times t31 and t32, and main injection is performed between times t33 and t35.
Further, as shown in FIG. 13B, a voltage is applied to the fuel for main injection between times t34 and t36.

In this case, as shown in FIG. 14A, since the fuel spray for pre-injection is not charged, the penetration is high and the fuel sprays far from the injector 10.
Next, as shown in FIG. 14B, the fuel spray for main injection is not charged from time t33 to time t34 at the beginning of injection, and charged after time t34 after a predetermined time has elapsed from the start of injection. To do. Therefore, the initial stage of injection becomes high penetration, and the air near the wall surface of the combustion chamber 54 is entrained and burned. And after time t34, it becomes low penetration and wide diffusion, and combustion spreads. Therefore, as shown in FIG. 14C, combustion using the air near the center and the wall surface of the combustion chamber 54 is possible. In FIG. 14B, the fuel spray injected by the first pre-injection is indicated by a broken line.
The fuel supply device 1 of the sixth embodiment has the same operational effects as the fourth and fifth embodiments.

(Seventh embodiment)
A seventh embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 15A, in the seventh embodiment, pre-injection is performed during time t41-t42, and main injection is performed during time t44-t46.
Further, as shown in FIG. 15B, a voltage is applied to the fuel for main injection between times t43 and t45.

In the seventh embodiment, since the fuel spray for pre-injection is not charged, it has high penetration and flies far from the injector 10.
Next, the fuel spray for main injection is charged until the time t45 after the elapse of a predetermined time from the start of injection, resulting in low penetration and wide diffusion. After time t45, high penetration occurs and the air near the wall surface of the combustion chamber 54 is entrained and burned.
The fuel supply device 1 according to the seventh embodiment has the same effects as the fourth to sixth embodiments.

(Eighth embodiment)
An eighth embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 16A, in the eighth embodiment, pre-injection is performed during time t51-t52, and main injection is performed during time t54-t55.
Also, as shown in FIG. 16 (B), a voltage is applied to the fuel for main injection between times t53 and t55.

In the eighth embodiment, since the fuel spray for pre-injection is not charged, it has high penetration and flies far from the injector 10.
Next, the fuel spray for main injection is charged from the start of injection to the end of injection, resulting in low penetration and wide diffusion.
The fuel supply device 1 according to the eighth embodiment has the same effects as the fourth to seventh embodiments.

(Other embodiments)
(1) In the first and third embodiments described above, the fuel supply device 1 is configured to apply a voltage to the needle and the nozzle to directly charge the fuel. On the other hand, in another embodiment, the fuel supply device 1 may have a configuration in which a donut-shaped electrode is provided on the downstream side of the nozzle hole 15 and the fuel is charged by an induced magnetic field.

(2) In the first and third embodiments described above, the needle valve 12 and the nozzle body 11 are electrodes. On the other hand, in other embodiments, electrodes may be provided in the fuel passage 13 inside the injector 10 separately from the needle valve 12 and the nozzle body 11. In this case, the electrode corresponds to an example of “charging means” described in the claims.

(3) In the above-described embodiment, the ECU 30 stores the dielectric constant of the fuel stored in the fuel tank 2 in advance. On the other hand, in another embodiment, the fuel physical property sensor 23 may detect both the fuel dielectric constant and the electric conductivity without storing the fuel dielectric constant in the ECU 30 in advance.

(4) In the above-described embodiment, the ECU 30 controls both the voltage applied to the fuel and the voltage application time based on the dielectric constant or electrical conductivity of the fuel supplied to the injector 10. On the other hand, in other embodiments, the ECU 30 may control at least one of the voltage applied to the fuel and the voltage application time based on the dielectric constant or electrical conductivity of the fuel supplied to the injector 10. .

(5) In the embodiment described above, the ECU 30 controls both the voltage applied to the fuel and the voltage application time based on the flow rate of the fuel flowing through the injector 10. On the other hand, in other embodiments, the ECU 30 may control at least one of the voltage applied to the fuel and the voltage application time based on the flow rate of the fuel flowing through the injector 10.

(6) In the above-described embodiment, only the electric conductivity of the fuel is detected by the fuel physical property sensor 23. On the other hand, in other embodiments, the fuel physical property sensor 23 may detect the electric conductivity and dielectric constant of the fuel.

(7) In the above-described embodiment, the injector 10 is configured to directly inject and supply fuel to the combustion chamber of the internal combustion engine. On the other hand, in other embodiments, the injector 10 may inject and supply fuel to the intake passage or the exhaust passage of the internal combustion engine.
Thus, the present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1 ... Fuel supply apparatus 11 ... Nozzle main body (charging means)
12 ... Needle valve (charging means)
20 ... Booster circuit (charging means)
30 ... Electronic control unit (ECU, control means)
40 ... Additive tank (additive mixing means)
41,411,412,413 ... additive supply path (additive mixing means)
42 ... Solenoid valve (additive mixing means)
43 ... Additive pressurizing pump (additive mixing means)
44, 45 ... Electrodes (charging means)

Claims (13)

A fuel tank (2) for storing fuel;
A fuel pressurizing pump (3) for pressurizing the fuel pumped from the fuel tank;
An injector (10) for spraying fuel pressurized by the fuel pressurizing pump onto an internal combustion engine;
Charging means (11, 12, 20, 44, 45) for charging fuel injected from the injector;
A fuel property sensor (23) for detecting a dielectric constant or electric conductivity of fuel flowing through a fuel path from the fuel tank to the injector;
Additive mixing means (40, 41, 42, 43, 411, 412, 413) for mixing an additive that changes the dielectric constant and electric conductivity of the fuel flowing in the fuel path;
Control means (30) for adjusting the amount of the additive mixed with the fuel by the additive mixing means based on the dielectric constant or electrical conductivity of the fuel detected by the fuel physical property sensor, A fuel supply device (1) for an internal combustion engine.   The control means determines the amount of the additive that the additive mixing means mixes with the fuel from the dielectric constant or electrical conductivity of the fuel detected by the fuel physical property sensor and the dielectric constant and electrical conductivity of the additive. The fuel supply device for an internal combustion engine according to claim 1, wherein: The control means stores in advance a dielectric constant of fuel stored in the fuel tank,
3. The fuel supply device for an internal combustion engine according to claim 1, wherein the fuel property sensor outputs only a signal corresponding to electric conductivity to the control means.   The fuel for an internal combustion engine according to any one of claims 1 to 3, wherein the additive mixing means mixes the additive with the fuel flowing between the fuel tank and the fuel pressurizing pump. Feeding device.   The fuel supply device for an internal combustion engine according to any one of claims 1 to 3, wherein the additive mixing unit mixes the additive with the fuel flowing through the injector.   6. The fuel supply device for an internal combustion engine according to claim 5, wherein the control means adjusts an amount of the additive mixed with the fuel by the additive mixing means based on a flow rate of the fuel flowing through the injector. .   The fuel supply apparatus for an internal combustion engine according to claim 5 or 6, wherein the charging means applies a voltage to the additive. The additive is
Biofuels containing aldehydes, alcohols or ketones,
Liquid fuel additives including aldehydes, alcohols or ketones,
Ionic liquid containing physical properties of aldehyde, alcohol or ketone,
Alternatively, the fuel supply device for an internal combustion engine according to any one of claims 1 to 7, wherein the fuel supply device is a solid or gas that becomes a liquid containing physical properties of aldehyde, alcohol, or ketone after dissolution.   The fuel passage (13) or the nozzle hole (15) located on the downstream side of the charging means with respect to the charging means is subjected to surface treatment with an insulating material (16) capable of suppressing the discharge of electric charges charged in the fuel. 9. The fuel supply device for an internal combustion engine according to claim 1, wherein the fuel supply device is an internal combustion engine.   9. The fuel passage or the nozzle hole located on the downstream side of the fuel with respect to the charging means is formed of an insulating material capable of suppressing discharge of electric charges charged in the fuel. The fuel supply device for an internal combustion engine according to one item.   The said control means controls at least any one of the voltage applied to the said charging means, or voltage application time based on the dielectric constant or electrical conductivity of a fuel, The any one of Claim 1 to 10 characterized by the above-mentioned. A fuel supply device for an internal combustion engine according to claim 1.   The said control means controls at least any one of the voltage applied to the said charging means, or voltage application time based on the flow volume of the fuel which flows through the said injector, The Claim 1 characterized by the above-mentioned. A fuel supply device for an internal combustion engine as described. A control method for controlling driving of the fuel supply device according to any one of claims 1 to 13,
A physical property detection step (S10) for detecting a dielectric constant or electric conductivity of the fuel by the fuel physical property sensor;
Addition for setting the amount of the additive mixed with the fuel by the additive mixing means based on the dielectric constant or electrical conductivity of the fuel detected by the physical property detection step and the dielectric constant or electrical conductivity of the additive And a quantity setting step (S13).

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