JP2009138609A - Fuel supply device and internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress knocking when knocking resistance performance of fuel supplied to an internal combustion engine is low. <P>SOLUTION: A fuel supply device 10 supplying fuel to the internal combustion engine 1 includes a fuel tank 13 storing fuel F, a property improved fuel vessel 11 storing property improved fuel FI mixing knocking resistance improving agent IL into the fuel F, and a selector valve 18. The fuel F is transferred to the property improved fuel vessel 11 from the fuel tank, and knocking resistance improving agent IL stored in an additive vessel 12 is transferred to the property improved fuel vessel 11 when knocking resistance performance of the fuel F is low. The property improved fuel FI in the property improved fuel vessel 11 is supplied to the internal combustion engine 1 in operation conditions where knocking of the internal combustion engine 1 easily occurs. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to fuel supply to an internal combustion engine.

  In an internal combustion engine such as a gasoline engine or a diesel engine, fuel is burned in a combustion space inside the engine. In an internal combustion engine, problems such as a decrease in output, an increase in fuel consumption, or an increase in noise may occur due to occurrence of knocking or poor ignitability depending on the properties of the fuel. Patent Document 1 discloses a technique for executing control for injecting an anti-knock agent into an air-fuel mixture when knocking of an internal combustion engine is detected and the temperature of the internal combustion engine is equal to or higher than a predetermined value.

Japanese Utility Model Publication No. 62-148752 (page 3)

  If an additive that changes the properties of the fuel, such as an anti-knock agent, is injected into the mixture as in the technique disclosed in Patent Document 1, it becomes difficult to control the mixing ratio between the additive and the mixture. The additive is consumed excessively, or the additive is insufficient.

  The present invention has been made in view of the above, and in improving the properties of the fuel supplied to the internal combustion engine, the fuel consumption is reliably suppressed while suppressing an increase in the consumption of the additive that changes the properties of the fuel. The purpose is to improve the properties.

  In order to solve the above-described problems and achieve the object, a fuel supply apparatus according to the present invention includes a fuel tank that stores fuel that is supplied to an internal combustion engine and combusts with combustion air in a combustion space of the internal combustion engine. A property-improving fuel container in which a property-improving fuel in which an additive that changes the property of the fuel is mixed is stored in the fuel, and the fuel supplied to the internal combustion engine is the fuel in the fuel tank. Or it can switch to the said property improvement fuel in the said property improvement fuel container.

  As a preferred aspect of the present invention, the fuel supply device includes a supply fuel switching means for switching the fuel supplied to the internal combustion engine to the fuel in the fuel tank or the property improving fuel in the property improving fuel container. It is desirable to be characterized.

  As a preferred aspect of the present invention, in the fuel supply device, a first fuel supply means for supplying the fuel in the fuel tank to the internal combustion engine, and the property improving fuel in the property improving fuel container are used as the internal combustion engine. And a second fuel supply means for supplying the engine.

  As a preferred aspect of the present invention, in the fuel supply device, it is desirable to determine the amount of the additive to be added to the fuel based on the property of the fuel.

  As a preferred aspect of the present invention, in the fuel supply apparatus, it is desirable that the additive is a knock resistance improving agent that improves a knock resistance performance of the fuel.

  As a preferred aspect of the present invention, in the fuel supply device, it is desirable to determine an input amount of the knock resistance improving agent to the fuel based on a knock resistance performance of the fuel.

  As a preferred aspect of the present invention, in the fuel supply apparatus, the additive is preferably an ignitability improver that improves the ignitability of the fuel.

  As a preferred aspect of the present invention, in the fuel supply device, it is desirable to determine an input amount of the ignitability improver for the fuel based on the ignitability of the fuel.

  In order to solve the above-described problems and achieve the object, an internal combustion engine according to the present invention is characterized in that fuel is supplied by the fuel supply device.

  According to the present invention, when improving the properties of the fuel supplied to the internal combustion engine, it is possible to reliably improve the properties of the fuel while suppressing an increase in the consumption of the additive that changes the properties of the fuel.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the best mode for carrying out the invention (hereinafter referred to as an embodiment). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, or those that are substantially the same, so-called equivalent ranges.

(Embodiment 1)
FIG. 1 is an apparatus configuration diagram illustrating an internal combustion engine and a fuel supply apparatus according to a first embodiment. In this embodiment, the fuel tank 13 for storing the fuel F of the internal combustion engine 1 and the fuel tank 13 are prepared separately, and the property improving fuel in which the fuel F is mixed with an additive that changes the property of the fuel F. And a property-improving fuel container 11 in which FI is stored. The fuel supplied to the internal combustion engine 1 can be switched to the fuel F in the fuel tank 13 or the property improving fuel FI in the property improving fuel container 11.

  Changing the property of the fuel F means changing the combustibility of the fuel F, that is, the knocking resistance and the ignitability. In the present embodiment, for the purpose of suppressing knocking of the internal combustion engine 1, a knocking resistance improver that improves resistance to knocking such as isopropyl alcohol is used as an additive that changes the properties of the fuel F.

  The internal combustion engine 1 is a so-called reciprocating internal combustion engine in which a piston 5 reciprocates in a cylinder 3. The cylinder 3 of the internal combustion engine 1 has one end attached to the cylinder head 2 and the other end attached to the crankcase 4. A space 3B surrounded by the inner surface of the cylinder 3, the top surface of the piston 5, and the inner surface of the cylinder head 2 is a space in which the fuel F supplied to the internal combustion engine 1 burns. This space 3B is referred to as a combustion space 3B. Hereinafter, the fuel F in the fuel tank 13, that is, the fuel before the additive that changes the property of the fuel F in the property improving fuel container 11 is mixed is referred to as the main fuel F.

  The main fuel F supplied to the internal combustion engine 1 is a fuel containing hydrocarbons. When the internal combustion engine 1 is a spark ignition engine, for example, gasoline is used, and the internal combustion engine 1 is a diesel engine. For example, light oil is used. Further, when the internal combustion engine 1 is an engine that can handle various types of fuel, oxygen-containing fuel such as alcohol, gasoline, LPG (Liquefied petroleum gas), or the like is used.

  The cylinder head 2 includes an intake port 8i that is an intake passage for introducing air (combustion air) A for combustion into the combustion space 3B, and a combustion gas (exhaust gas) after the fuel is burned in the combustion space 3B. ) An exhaust port 8e which is an exhaust passage for discharging Ex to the outside of the combustion space 3B is formed.

  The intake port 8i and the exhaust port 8e each open to the combustion space 3B, and the respective openings are formed in the cylinder head 2. An intake valve 9i is disposed at the opening of the intake port 8i, and an exhaust valve 9e is disposed at the opening of the exhaust port 8e. The intake valve 9i opens and closes the opening of the intake port 8i, and the exhaust valve 9e opens and closes the opening of the exhaust port 8e.

  The internal combustion engine 1 includes a fuel injection valve (hereinafter referred to as an in-cylinder injection valve) 31 in the cylinder head 2 as fuel supply means for injecting fuel into the combustion air A in the combustion space 3B. An ignition plug 30 is attached to the internal combustion engine 1 as ignition means for igniting an air-fuel mixture of fuel and combustion air A formed in the combustion space 3B in the cylinder head 2. The air-fuel mixture in the combustion space 3B is ignited by the discharge from the spark plug 30 and burns. Thus, the internal combustion engine 1 is a so-called direct injection spark ignition type internal combustion engine in which fuel is directly injected into the combustion space 3B by the in-cylinder injection valve 31.

  When the intake valve 9i is opened and the piston 5 moves to the bottom dead center, the combustion air A flows into the combustion space 3B from the opening of the intake port 8i (intake stroke). When performing homogeneous combustion, the in-cylinder injection valve 31 injects fuel into the combustion space 3B in the intake stroke. When the piston 5 passes through the bottom dead center and the piston 5 heads to the top dead center (that is, toward the cylinder head 2) with the intake valve 9i and the exhaust valve 9e closed, the fuel formed in the combustion space 3B The air-fuel mixture with the combustion air A is compressed and heated up (compression stroke). When stratified combustion is performed, the in-cylinder injection valve 31 injects fuel into the combustion space 3B in the compression stroke.

  Before the piston 5 reaches top dead center, the spark plug 30 discharges and ignites the compressed air-fuel mixture. Thereby, the air-fuel mixture in the combustion space 3B burns. Here, the in-cylinder injection valve 31 and the spark plug 30 are controlled by an engine ECU (Electronic Control Unit) 50.

  The piston 5 moves toward the bottom dead center by the combustion pressure when the air-fuel mixture burns (expansion stroke). The piston 5 that has passed through the bottom dead center moves again toward the top dead center. At this time, the exhaust valve 9e is opened, and the combustion gas (exhaust gas Ex) in the combustion space 3B is discharged to the exhaust port 8e (exhaust gas). Process). This completes one cycle of the internal combustion engine.

  When the piston 5 comes close to top dead center, the intake valve 9i is opened, the exhaust valve 9e is closed, and the next cycle of the internal combustion engine 1 is started. Thus, the internal combustion engine 1 is a four-stroke one-cycle internal combustion engine in which one cycle is completed while the piston 5 reciprocates twice within the cylinder 3. The reciprocating motion of the piston 5 is transmitted to the crankshaft 7 in the crankcase 4 via the connecting rod 6 and converted into rotational motion. Next, the fuel supply device 10 that supplies fuel to the internal combustion engine 1 will be described.

  The fuel supply device 10 is generated by mixing a fuel tank 13 that stores the main fuel F supplied to the internal combustion engine 1 and a knock resistance improving agent IL that improves the knock resistance of the main fuel F and the main fuel F. A property improving fuel container 11 in which the property improving fuel FI is stored. The fuel supplied to the internal combustion engine 1 is one of the main fuel F in the fuel tank 13 or the property improving fuel FI in the property improving fuel container 11.

  The fuel supplied to the internal combustion engine 1 is sent to the high-pressure pump 60, and after the pressure (fuel pressure) is further increased by the high-pressure pump 60, the fuel is sent to the fuel distribution pipe 61. The in-cylinder injection valve 31 is connected to the fuel distribution pipe 61, and the fuel in the fuel distribution pipe 61 pressurized to a predetermined pressure is supplied to the in-cylinder injection valve 31. Here, when the internal combustion engine 1 includes a plurality of cylinders 3, pistons 5 and in-cylinder injection valves 31, the in-cylinder injection valves 31 are connected to the fuel distribution pipes 61, and the combustion spaces 3 </ b> B in the respective cylinders 3. Is supplied with fuel.

  A fuel pressure adjustment valve 62 is attached to the fuel distribution pipe 61 as means for adjusting the fuel pressure in the fuel distribution pipe 61. The fuel pressure adjusting valve 62 is opened when the fuel pressure in the fuel distribution pipe 61 exceeds a preset pressure, and the fuel in the fuel distribution pipe 61 is supplied to the inlet side of the high-pressure pump 60 via the fuel relief passage 24. Return to. Thus, the fuel pressure adjustment valve 62 holds the fuel pressure in the fuel distribution pipe 61 at a preset value. The fuel pressure adjusting valve 62 may have a function of changing the set pressure by the engine ECU 50, or may be a valve that can be controlled to be opened and closed by the engine ECU 50.

  The fuel tank 13 is provided with a main fuel passage 21 for supplying the main fuel F to the internal combustion engine 1. Further, a property improving fuel passage 22 for supplying the property improving fuel FI to the internal combustion engine 1 is provided in the property improving fuel container 11. The property improving fuel container 11 is supplied with the main fuel F in the fuel tank 13 and a knock resistance improving agent IL for improving the knock resistance performance of the fuel F. As a result, the property improving fuel container 11 stores the property improving fuel FI mixed with the main fuel F added with the knock resistance improving agent IL.

  The knock resistance improving agent IL is stored in the additive container 12. The additive container 12 and the property-improving fuel container 11 are connected by an additive charging passage 19, and the fuel tank 13 is connected by a fuel transfer passage 20. The additive charging passage 19 is provided with an additive charging pump 16 as an additive introducing means. As a result, the knock resistance improving agent IL in the additive container 12 is supplied to the property improving fuel container 11. The fuel transfer passage 20 is provided with a fuel transfer pump 17 as a fuel introduction means. As a result, the main fuel F in the fuel tank 13 is supplied to the property improving fuel container 11. Then, the main fuel F and the knock resistance improver IL are mixed in the property improving fuel container 11 to produce the property improving fuel FI.

  A fuel pump 14 is provided in the main fuel passage 21 connected to the fuel tank 13 as fuel supply means. The fuel pump 14 sends main fuel F in the fuel tank 13 to an in-cylinder injection valve 31 that injects fuel into the combustion space 3B of the internal combustion engine 1. The property improving fuel passage 22 is provided with a property improving fuel pump 15 as a property improving fuel supply means. The property improving fuel pump 15 sends the property improving fuel FI in the property improving fuel container 11 to an in-cylinder injection valve 31 that injects fuel into the combustion space 3B of the internal combustion engine 1.

  Between the fuel tank 13 and the property improving fuel container 11 and the in-cylinder injection valve 31, there is provided a switching valve 18 which is a supply fuel switching means for switching the fuel supplied to the internal combustion engine 1 to the main fuel F or the property improving fuel FI. It is done. The switching valve 18 has two inlets and one outlet. A property improving fuel passage 22 is connected to one of the inlets of the switching valve 18, and a main fuel passage 21 is connected to the other. A fuel supply passage 23 is connected to the outlet of the switching valve 18. The fuel supply passage 23 is connected to a high-pressure pump 60 that pressurizes the fuel supplied to the in-cylinder injection valve 31.

  The switching valve 18 makes the fuel supply passage 23 communicate with either the property improving fuel passage 22 or the main fuel passage 21 by making the outlet communicate with either one of the two inlets. As a result, either the main fuel F discharged from the fuel pump 14 or the property improving fuel FI discharged from the property improving fuel pump 15 is supplied to the high pressure pump 60. The high-pressure pump 60 supplies either the main fuel F or the property improving fuel FI to the fuel distribution pipe 61, and either the main fuel F or the property improving fuel FI is supplied from the fuel distribution pipe 61 to the in-cylinder injection valve 31. Supplied. The in-cylinder injection valve 31 injects either the main fuel F or the property improving fuel FI into the combustion space 3B.

  The fuel pump 14, the property improving fuel pump 15, the additive charging pump 16, the fuel transfer pump 17, and the switching valve 18 are controlled by a fuel supply control device 51 provided in the engine ECU 50. When necessary, the fuel supply control device 51 drives the additive charging pump 16 and the fuel transfer pump 17, so that the property improving fuel FI is created and stored in the property improving fuel container 11.

  The engine ECU 50 including the fuel supply control device 51 includes an input signal from a knock sensor 40 attached to the internal combustion engine 1, a property improving fuel pump 15, an additive charging pump 16, a fuel transfer pump 17, a switching valve 18, and the like. An input / output unit 54 for inputting / outputting an output signal to the engine, a processing unit 50P, and a storage unit 53 for storing various maps used for controlling the internal combustion engine 1.

  The processing unit 50P includes, for example, a memory and a CPU (Central Processing Unit). The processing unit 50P includes a fuel supply control device 51 that executes fuel supply control according to the present embodiment and an engine control unit 52 that controls the internal combustion engine 1. That is, in the present embodiment, the fuel supply control device 51 is realized as one function of the processing unit 50P. Here, the fuel supply control device 51 includes a control condition determination unit 51A, a fuel property determination unit 51B, and a fuel property adjustment unit 51C, which perform fuel supply control according to the present embodiment. The storage unit 53 is a nonvolatile memory such as a flash memory, a memory that can only be read such as a ROM (Read Only Memory), a memory that can be read and written such as a RAM (Random Access Memory), or a combination thereof. Can be configured.

  When the internal combustion engine 1 is operated under an operating condition in which knocking is likely to occur, the fuel supply control device 51 switches the switching valve 18 and drives the property improving fuel pump 15, so that the properties in the property improving fuel container 11 are The improved fuel FI is supplied to the internal combustion engine 1. For example, the internal combustion engine 1 is operated with the property-improving fuel FI, particularly during low-rotation, medium-high load operation where knocking resistance is a problem. As a result, the internal combustion engine 1 is less likely to cause knocking even under operating conditions where knocking resistance is a problem, and therefore, fuel consumption and output reduction of the internal combustion engine 1 can be suppressed.

  In the present embodiment, the property improving fuel FI is made in advance and stored in the property improving fuel container 11. Accordingly, when it is desired to suppress knocking of the internal combustion engine 1, the property improving fuel FI can be immediately supplied to the internal combustion engine 1. Further, since the volume of the property-improving fuel container 11 is smaller than the volume of the fuel tank, a small amount of knock resistance is obtained as compared with the case where the knock resistance improver IL is directly fed into the main fuel F in the fuel tank 13. With the improver IL, a property-improving fuel FI having the necessary anti-knocking performance can be obtained. Thereby, the consumption of the knock resistance improving agent IL can be suppressed. Further, since the main fuel F and the knock resistance improving agent IL are mixed in the property improving fuel container 11 having a volume smaller than that of the fuel tank 13, the mixing of both proceeds rapidly.

  FIG. 2 is an apparatus configuration diagram illustrating an internal combustion engine and a fuel supply apparatus according to a first modification of the first embodiment. This modification is substantially the same as that of the first embodiment, except that a port injection valve 32 for injecting fuel into the intake port 8i is provided as fuel supply means instead of the in-cylinder injection valve 31 shown in FIG. Since the other configuration of the present modification is the same as that of the first embodiment, the same reference numeral is given to the same configuration, and description thereof is omitted.

  The port injection valve 32 provided in the fuel supply device 10a is attached to the port injection valve fuel distribution pipe 63, and the operation is controlled by the engine ECU 50. The port injection valve 32 is supplied with fuel from the port injection valve fuel distribution pipe 63 and injects the fuel into the combustion air A in the intake port 8i of the internal combustion engine 1a. Thereby, an air-fuel mixture in which the fuel and the combustion air A are sufficiently mixed can be formed.

  A property improving fuel passage 22 is connected to one of the inlets of the switching valve 18, and a main fuel passage 21 is connected to the other. A fuel supply passage 23 is connected to the outlet of the switching valve 18. The fuel supply passage 23 is connected to the fuel distribution pipe 63 for the port injection valve, and either the main fuel F discharged from the fuel pump 14 or the property improving fuel FI discharged from the property improving fuel pump 15 is supplied. The fuel is supplied to the port injector fuel distribution pipe 63.

  With such a configuration, when the internal combustion engine 1a is operated under operating conditions where knocking is likely to occur, the fuel supply control device 51 switches the switching valve 18 and drives the property improving fuel pump 15 to improve the property. The property improving fuel FI in the fuel container 11 is supplied to the port injector fuel distribution pipe 63. Accordingly, the port injection valve 32 supplies the property improving fuel FI to the internal combustion engine 1a when the internal combustion engine 1 is operated under an operation condition in which knocking is likely to occur. As a result, in this modified example as well as in the first embodiment, the internal combustion engine 1a is less likely to be knocked even under operating conditions where knocking resistance is a problem, so that fuel consumption and output reduction of the internal combustion engine 1a are suppressed. it can.

  FIG. 3 is an apparatus configuration diagram illustrating an internal combustion engine and a fuel supply apparatus according to a second modification of the first embodiment. The present modification is substantially the same as the first and second modifications, but includes the in-cylinder injection valve 31 shown in FIG. 1 and the port injection valve 32 shown in FIG. The difference is that the switching valve 18 is omitted by injecting the main fuel F from the in-cylinder injection valve 31 as the fuel supply means and injecting the property improving fuel FI from the port injection valve 32 as the second fuel supply means. . Since other configurations of the present modification are the same as those of the first embodiment and the first modification, the same reference numerals are given to the same configurations, and descriptions thereof are omitted.

  The fuel supply device 10b improves the property of supplying the main fuel F from the fuel tank 13 to the in-cylinder injection valve 31 and the property improving fuel FI from the property improving fuel container 11 to the port injection valve 32. Fuel is supplied to the internal combustion engine 1b by two systems including a fuel supply system. In the main fuel supply system, main fuel F discharged from the fuel pump 14 is supplied to the high-pressure pump 60, where the pressure is increased and supplied to the in-cylinder injection valve 31. In the property improving fuel supply system, the property improving fuel FI discharged from the property improving fuel pump 15 is sent to the port injector fuel distribution pipe 63 through the property improving fuel passage 22, and from here the port injector 32. Supplied to.

  The fuel pump 14 and the property improving fuel pump 15 are controlled by a fuel supply control device 51 provided in the engine ECU 50. With such a configuration, when the internal combustion engine 1b is operated under an operation condition in which knocking is likely to occur, the fuel supply control device 51 drives the property improving fuel pump 15 and the property in the property improving fuel container 11 is increased. The improved fuel FI is supplied to the fuel distribution pipe 63 for the port injection valve. Accordingly, the port injection valve 32 supplies the property improving fuel FI to the internal combustion engine 1b when the internal combustion engine 1 is operated under an operation condition in which knocking is likely to occur.

  As a result, in this modified example as well, as in the first and first modified examples, the internal combustion engine 1b is less likely to be knocked even under operating conditions in which anti-knocking performance is a problem. And output reduction can be suppressed. Further, since the property improving fuel FI is supplied to the internal combustion engine 1b by the port injection valve 32 that facilitates the mixing of the fuel and the combustion air A, the homogenization of the property improving fuel FI is promoted and the occurrence of knocking is further suppressed. it can. Next, fuel supply control according to the present embodiment will be described.

  FIG. 4 is a flowchart illustrating a procedure of fuel supply control according to the first embodiment. In the following description, the fuel supply device 10 and the internal combustion engine 1 shown in FIG. 1 are taken as an example in principle. However, the fuel supply devices 10a and 10b and the internal combustion engines 1a and 1b shown in FIGS. Used as In executing the fuel supply control according to the present embodiment, in step S101, the control condition determination unit 51A of the fuel supply control device 51 passes a predetermined time after supplying the main fuel F of the internal combustion engine 1 to the fuel tank 13. Determine whether or not. Thereby, it is determined whether or not the main fuel F supplied to the fuel tank 13 has spread to the main fuel passage 21 and the fuel supply passage 23.

  Further, when the main fuel F is refueled, the main fuel F remaining in the fuel tank 13 and the newly refueled main fuel F are mixed, and it takes a certain amount of time for the properties to become stable. The determination accuracy of the fuel property (anti-knocking performance in the present embodiment) may be reduced. For this reason, it is determined whether or not a predetermined time has elapsed after refueling in step S101, and when the predetermined time has not elapsed, the fuel supply control according to the present embodiment is not executed, so that the knock resistance improving agent IL is reduced. While avoiding excessive consumption, the knocking resistance performance of the main fuel F can be reliably improved.

  When it is determined No in step S101, that is, when the control condition determination unit 51A determines that a predetermined time has not elapsed after refueling, the fuel supply control according to the present embodiment is terminated. Here, the elapsed time after refueling can be counted by the control condition determination unit 51A using a counter function provided in the engine ECU 50. For example, the control condition determination unit 51A determines that there has been refueling when the fuel meter of the vehicle on which the fuel supply device 10 is mounted has increased from the current time, and counts the elapsed time after refueling based on that time. The predetermined time after refueling used for determining whether or not to execute the fuel supply control according to the present embodiment is determined in advance by an experiment or the like.

  When it is determined Yes in step S101, that is, when the control condition determining unit 51A determines that a predetermined time has elapsed after refueling, the process proceeds to step S102. In step S102, the control condition determination unit 51A compares the amount of property improving fuel FI (properties improving fuel amount) Qi in the property improving fuel container 11 with the property improving fuel amount threshold Qic. This is to determine the amount of the property improving fuel FI remaining in the property improving fuel container 11, and when a certain amount of the property improving fuel FI remains in the property improving fuel container 11, this is used. Because. In this way, excessive consumption of the knock resistance improving agent IL is suppressed. The property improving fuel amount threshold value Qic is determined in advance by an experiment or the like.

  When it is determined No in step S102, that is, when the control condition determination unit 51A determines that Qi ≧ Qic, the fuel supply control according to the present embodiment is terminated. If it is determined Yes in step S102, that is, if the control condition determination unit 51A determines that Qi <Qic, the process proceeds to step S103.

  In step S103, the fuel property determination unit 51B of the fuel supply control device 51 obtains a knock resistance index Cn. The knock resistance index threshold value Cno is an index indicating the knock resistance performance of the main fuel F in the fuel tank 13 supplied to the internal combustion engine 1. The smaller the knock resistance index Cn, the more the knock resistance performance of the main fuel F is. Lower. When knocking occurs in the internal combustion engine 1, the ignition timing of the internal combustion engine 1 is retarded. Therefore, the anti-knocking performance of the main fuel F used at that time is known depending on how much the ignition timing CAPn when the knocking of the internal combustion engine 1 is detected is retarded with respect to the original ignition timing CAP. be able to. Thus, for example, the retarded degree of the ignition timing of the internal combustion engine 1 when knocking occurs can be used as the knock resistance index Cn. Whether knocking has occurred in the internal combustion engine 1 can be detected by the knock sensor 40.

  If the knock resistance index Cn is obtained in step S103, the process proceeds to step S104. In step S104, the fuel property determination unit 51B compares the knock resistance index Cn obtained in step S103 with a predetermined knock resistance index threshold Cno. The knock resistance index threshold Cno is set to a value that allows the knock resistance of the main fuel F to be tolerated. Knock resistance index threshold Cno is determined in advance by experiments or the like.

  When it is determined No in step S104, that is, when the fuel property determination unit 51B determines that Cn ≧ Cno, it can be determined that the knocking resistance performance of the main fuel F is acceptable. In this case, the fuel supply control according to the present embodiment is terminated. When it is determined Yes in step S104, that is, when the fuel property determination unit 51B determines that Cn <Cno, it can be determined that the anti-knocking performance of the main fuel F is unacceptable. In this case, the knock resistance improver IL is added to the main fuel F to create a property improving fuel FI with improved knock resistance performance of the main fuel F, and stored in the property improving fuel container 11.

  In step S <b> 105, the fuel property adjusting unit 51 </ b> C of the fuel supply control device 51 drives the fuel transfer pump 17 to transfer the main fuel F in the fuel tank 13 into the property improving fuel container 11. Next, in step S106, the fuel property adjusting unit 51C calculates the amount (additive additive amount) Xn of the knock resistance improving agent IL to be introduced into the main fuel F in the property improving fuel container 11.

  The additive input amount Xn is, for example, the required concentration D of the knock resistance improving agent IL obtained based on the knock resistance index Cn, and the amount of the main fuel F transferred into the property improving fuel container 11 (fuel transfer amount). It can be obtained by the product (D × V2) with V2. The fuel transfer amount V2 can be obtained from the amount of main fuel F discharged by the fuel transfer pump 17. Usually, since the discharge amount per unit time of the fuel transfer pump 17 is constant, the fuel transfer amount V2 can be obtained by multiplying the discharge amount per unit time by the drive time of the fuel transfer pump 17.

  When Cn <Cno, the anti-knocking performance of the main fuel F may be improved by an amount corresponding to at least the difference ΔCn (= Cno−Cn) between Cno and Cn. The required concentration D of the knock resistance improving agent IL is equivalent to ΔCn, and is required for improving the knocking resistance performance of the main fuel F by the amount corresponding to ΔCn. Amount.

  The required concentration D of the knock resistance improving agent IL with respect to ΔCn (= Cno−Cn) is obtained and mapped in advance by experiment, analysis, etc., and stored in the storage unit 53 of the engine ECU 50. When the knock resistance index threshold Cno is a constant, the map is described in relation to the knock resistance index Cn and the required concentration D of the knock resistance improver IL. The fuel property adjusting unit 51C reads the map from the storage unit 53, gives the current knock resistance index Cn to the map, and obtains the necessary concentration D of the corresponding knock resistance improving agent IL. Then, the additive input amount Xn is obtained by the product (D × V2) of the necessary concentration D of the obtained knock resistance improving agent IL and the fuel transfer amount V2.

  Thus, in the present embodiment, the additive input amount Xn is obtained based on the properties of the main fuel F, that is, the combustion state of the fuel combusted in the internal combustion engine 1 during operation of the internal combustion engine 1. Necessary and sufficient knock resistance improving agent IL for improving the knocking performance can be introduced into the main fuel F. Thus, knocking of the internal combustion engine 1 can be reliably suppressed while suppressing excessive consumption of the knock resistance improving agent IL. That is, it is possible to suppress the excess or deficiency of the knock resistance improving agent IL to be introduced into the fuel.

  When the additive input amount Xn is obtained in step S106, the process proceeds to step S107. In step S107, the fuel property adjusting unit 51C drives the additive charging pump 16, and converts the knock resistance improving agent IL in the additive container 12 into the property improving fuel by the amount Xn of the additive charging obtained in step S106. The main fuel F in the container 11 is charged. As a result, the anti-knocking performance of the main fuel F in the property improving fuel container 11 is improved, so that knocking of the internal combustion engine 1 is suppressed. As a result, it is possible to suppress a decrease in output of the internal combustion engine 1 and an increase in fuel consumption due to knocking.

  In supplying the property improving fuel FI in the property improving fuel container 11 to the internal combustion engine 1, first, the control condition determining unit 51 </ b> A determines the operating condition of the internal combustion engine 1. When the internal combustion engine 1 is likely to be knocked, for example, when the internal combustion engine 1 is operated at a high load during low rotation, the fuel property adjusting unit 51C operates the switching valve 18 to generate the property improving fuel FI. Supply to the internal combustion engine 1. By doing in this way, while being able to suppress knocking reliably on the driving | running condition which is easy to generate | occur | produce knocking, consumption of property improvement fuel FI, ie, consumption of knock resistance improving agent IL, can be suppressed.

  As described above, in the present embodiment, a fuel tank that stores fuel for an internal combustion engine and a fuel that is prepared separately from the fuel tank and that mixes fuel and an additive that changes the properties of the fuel are stored. And a property improving fuel container. Thus, the property improving fuel can be produced in the property improving fuel container at a predetermined mixing ratio of the additive and the fuel, so that excess or deficiency of the additive to be added to the fuel can be suppressed. As a result, it is possible to reliably improve the properties of the fuel while suppressing an increase in the consumption of the additive that changes the properties of the fuel. In addition, since the amount of additive to be added is determined based on the properties of the fuel, that is, the combustion state of the fuel during operation of the internal combustion engine, the excess or deficiency of the additive to be added to the fuel can be more reliably avoided, The property of the fuel can be improved reliably while suppressing an increase in the consumption of the additive that changes the property.

(Embodiment 2)
FIG. 5 is an apparatus configuration diagram showing the internal combustion engine and the fuel supply apparatus according to the second embodiment. This embodiment has substantially the same configuration as that of the first embodiment, except that the internal combustion engine 1c is a diesel engine, and an ignitability improver that improves the ignitability of the main fuel F is used as an additive. Since the other configuration is the same as that of the first embodiment, the same reference numeral is given to the same configuration, and the description is omitted. In the present embodiment, in order to improve the ignitability of the main fuel F supplied to the internal combustion engine 1c, the combustibility of the main fuel F, that is, the ignitability is changed by the additive.

  An internal combustion engine 1c shown in FIG. 5 is a diesel internal combustion engine, and for example, light oil is used as the main fuel F. The internal combustion engine 1c includes a fuel injection valve 33 as fuel supply means for injecting fuel into the cylinder head 2 to the combustion air A in the combustion space 3B. When the intake valve 9i is opened and the piston 5 moves to the bottom dead center, the combustion air A flows into the combustion space 3B from the opening of the intake port 8i (intake stroke).

  When the piston 5 passes through the bottom dead center and the piston 5 moves toward the top dead center (that is, in the direction of the cylinder head 2) with the intake valve 9i and the exhaust valve 9e closed, the combustion air A in the combustion space 3B is The temperature is increased by compression (compression process). When the fuel injection valve 33 injects fuel into the combustion air A in the combustion space 3B that has been compressed and heated, the fuel spontaneously ignites. Here, the fuel injection valve 33 is controlled by an engine ECU (Electronic Control Unit) 50.

  The piston 5 moves toward the bottom dead center by the combustion pressure when the fuel burns (expansion stroke). The piston 5 that has passed through the bottom dead center moves again toward the top dead center. At this time, the exhaust valve 9e is opened, and the combustion gas (exhaust gas Ex) in the combustion space 3B is discharged to the exhaust port 8e (exhaust gas). Process). This completes one cycle of the internal combustion engine.

  When the piston 5 comes close to the top dead center, the intake valve 9i is opened, the exhaust valve 9e is closed, the combustion air A flows into the combustion space 3B from the intake port 8i, and the next cycle of the internal combustion engine 1 starts. To do. Thus, the internal combustion engine 1c is a four-stroke one-cycle internal combustion engine in which one cycle is completed while the piston 5 reciprocates twice within the cylinder 3. The reciprocating motion of the piston 5 is transmitted to the crankshaft 7 in the crankcase 4 via the connecting rod 6 and converted into rotational motion.

  The structure of the fuel supply device 10c that supplies fuel to the internal combustion engine 1c is the same as that of the fuel supply device 10 shown in FIG. 1, and the additive stored in the additive container 12 is the ignitability improver IP, and the fuel tank 13 is different in that the fuel stored in 13 is light oil or the like. Here, the ignitability improver IP is an additive for improving the cetane number, and for example, stabilized beta carotene or the like is used. Next, fuel supply control according to the present embodiment will be described.

  FIG. 6 is a flowchart illustrating a procedure of fuel supply control according to the second embodiment. Steps S201 and S202 of the fuel supply control are the same as steps S101 and S102 of the fuel supply control described above, and a description thereof will be omitted. In step S203, the fuel property determination unit 51B of the fuel supply control device 51 obtains a fuel ignitability index Ci.

  The fuel ignitability index Ci is an index indicating the ignitability of the main fuel F in the fuel tank 13 supplied to the internal combustion engine 1. The smaller the fuel ignitability index Ci, the lower the ignitability of the main fuel F. That is, the main fuel F becomes difficult to ignite, and the noise of the internal combustion engine 1c increases or the emission deteriorates. When the ignitability is lowered, the combustion pressure of the internal combustion engine 1c is reduced. For example, the ignitability of the main fuel F is changed by the change in the combustion pressure of the internal combustion engine 1c by the in-cylinder pressure sensor 41 attached to the cylinder head 2 of the internal combustion engine 1c. I can know. That is, the combustion pressure of the internal combustion engine 1 can be used as the fuel ignitability index Ci. Further, when the ignitability of the main fuel F decreases, the rotation fluctuation of the internal combustion engine 1c occurs, so that the ignitability of the main fuel F can be known from the rotation fluctuation of the crankshaft 7 of the internal combustion engine 1c. That is, the rotational fluctuation of the internal combustion engine 1 can be used as the fuel ignitability index Ci.

  If the fuel ignitability index Ci is obtained in step S203, the process proceeds to step S204. In step S204, the fuel property determination unit 51B compares the fuel ignitability index Ci obtained in step S203 with a predetermined fuel ignitability index threshold Cio. The fuel ignitability index threshold Cio is set to a value that allows the noise and emission of the internal combustion engine 1c. The fuel ignitability index threshold Cio is determined in advance by experiments or the like.

  If it is determined No in step S204, that is, if the fuel property determination unit 51B determines that Ci ≧ Cio, it can be determined that the ignitability of the main fuel F is acceptable. In this case, the fuel supply control according to the present embodiment is terminated. When it is determined Yes in step S204, that is, when the fuel property determination unit 51B determines that Ci <Cio, it can be determined that the ignitability of the main fuel F is unacceptable. In this case, the ignitability improver IP is added to the main fuel F to produce a property improving fuel FI in which the ignitability of the main fuel F is improved and stored in the property improving fuel container 11.

  In step S <b> 205, the fuel property adjusting unit 51 </ b> C of the fuel supply control device 51 drives the fuel transfer pump 17 to transfer the main fuel F in the fuel tank 13 into the property improving fuel container 11. Next, in step S206, the fuel property adjusting unit 51C calculates the amount (additive additive amount) Xn of the ignitability improver IP to be injected into the main fuel F in the property improving fuel container 11.

  The additive input amount Xn is, for example, the required concentration D of the ignitability improver IP obtained based on the fuel ignitability index Ci, and the amount of main fuel F transferred into the property improving fuel container 11 (fuel transfer amount) V2. (D × V2). The fuel transfer amount V2 can be obtained from the amount of main fuel F discharged by the fuel transfer pump 17. Usually, since the discharge amount per unit time of the fuel transfer pump 17 is constant, the fuel transfer amount V2 can be obtained by multiplying the discharge amount per unit time by the drive time of the fuel transfer pump 17.

  In the case of Ci <Cio, the ignitability of the main fuel F may be improved by an amount corresponding to at least the difference ΔCi (= Cio−Ci) between Cio and Ci. The required concentration D of the ignitability improver IP is the amount of the ignitability improver IP that is required to improve the ignitability of the main fuel F by an amount corresponding to ΔCi and that is supplied to the main fuel F per unit volume. .

  The necessary concentration D of the ignitability improver IP with respect to ΔCi (= Cio−Ci) is obtained and mapped in advance by experiment, analysis, etc., and stored in the storage unit 53 of the engine ECU 50. When the fuel ignitability index threshold Cio is a constant, the map is described in relation to the fuel ignitability index Ci and the required concentration D of the ignitability improver IP. The fuel property adjusting unit 51C reads the map from the storage unit 53, gives the current fuel ignitability index Ci to the map, and obtains the required concentration D of the corresponding ignitability improver IP. And additive addition amount Xn is calculated | required by the product (DxV2) of the required density | concentration D of the acquired ignitability improvement agent IP, and the fuel transfer amount V2.

  Thus, in the present embodiment, the additive input amount Xn is obtained based on the properties of the main fuel F, that is, the combustion state of the fuel combusted in the internal combustion engine 1 during operation of the internal combustion engine 1. In order to improve the ignitability, the necessary and sufficient ignitability improver IP can be introduced into the main fuel F. Thus, the ignitability of the main fuel F can be reliably improved while suppressing excessive consumption of the ignitability improver IP. That is, it is possible to suppress the excess and deficiency of the ignitability improver IP to be introduced into the fuel.

  When the additive input amount Xn is obtained in step S206, the process proceeds to step S207. In step S207, the fuel property adjusting unit 51C drives the additive charging pump 16, and supplies the ignitability improving agent IP in the additive container 12 by the amount of the additive charging amount Xn obtained in step S206. 11 to the main fuel F in the tank. As a result, the ignitability of the main fuel F in the property improving fuel container 11 is improved, so that deterioration of noise and emission of the internal combustion engine 1 due to low ignitability of the main fuel F can be suppressed.

  In supplying the property improving fuel FI in the property improving fuel container 11 to the internal combustion engine 1, first, the control condition determining unit 51 </ b> A determines the operating condition of the internal combustion engine 1. Then, the fuel property adjusting unit 51C operates the switching valve 18 to operate the internal combustion engine 1 in which the ignitability is a problem, for example, during cold operation or light load operation of the internal combustion engine 1, and the property improving fuel FI is obtained. Supply to the internal combustion engine 1. In this way, the ignitability can be reliably improved under the operating conditions where the ignitability is a problem, and the consumption of the property improving fuel FI, that is, the consumption of the ignitability improver IP can be suppressed.

  As described above, the fuel supply device and the internal combustion engine according to the present invention are useful for supplying fuel to a gasoline engine, a diesel engine, and the like, and are particularly suitable for improving the knocking resistance and ignition performance.

1 is an apparatus configuration diagram illustrating an internal combustion engine and a fuel supply apparatus according to Embodiment 1. FIG. FIG. 5 is a device configuration diagram illustrating an internal combustion engine and a fuel supply device according to a first modification of the first embodiment. FIG. 6 is a device configuration diagram illustrating an internal combustion engine and a fuel supply device according to a second modification of the first embodiment. 3 is a flowchart illustrating a procedure of fuel supply control according to the first embodiment. FIG. 3 is a device configuration diagram illustrating an internal combustion engine and a fuel supply device according to a second embodiment. 6 is a flowchart illustrating a procedure of fuel supply control according to the second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a, 1b, 1c Internal combustion engine 2 Cylinder head 3 Cylinder 3B Combustion space 4 Crankcase 5 Piston 6 Connecting rod 7 Crankshaft 10, 10a, 10b, 10c Fuel supply device 11 Property improvement fuel container 12 Additive container 13 Fuel tank DESCRIPTION OF SYMBOLS 14 Fuel pump 15 Property improvement fuel pump 16 Additive injection pump 17 Fuel transfer pump 18 Switching valve 19 Additive supply passage 20 Fuel transfer passage 21 Main fuel passage 22 Property improvement fuel passage 23 Fuel supply passage 24 Fuel relief Passage 30 Spark plug 31 In-cylinder injection valve 32 Port injection valve 33 Fuel injection valve 40 Knock sensor 41 In-cylinder pressure sensor 50 Engine ECU
50P processing unit 51 fuel supply control device 51A control condition determination unit 51B fuel property determination unit 51C fuel property adjustment unit 52 engine control unit 53 storage unit 54 input / output unit 60 high pressure pump 61 fuel distribution pipe 62 fuel pressure adjustment valve 63 port injection valve Fuel distribution pipe

Claims (9)

A fuel tank for storing fuel supplied to the internal combustion engine and combusted with combustion air in the combustion space of the internal combustion engine;
A property improving fuel container in which a property improving fuel in which an additive that changes the property of the fuel is mixed is stored in the fuel; and
A fuel supply device characterized in that the fuel supplied to the internal combustion engine can be switched to the fuel in the fuel tank or the property improving fuel in the property improving fuel container.   2. The fuel supply device according to claim 1, further comprising a supply fuel switching unit that switches the fuel supplied to the internal combustion engine to the fuel in the fuel tank or the property improving fuel in the property improving fuel container. .   First fuel supply means for supplying the fuel in the fuel tank to the internal combustion engine; and second fuel supply means for supplying the property improvement fuel in the property improvement fuel container to the internal combustion engine. The fuel supply device according to claim 1.   The fuel supply device according to any one of claims 1 to 3, wherein an amount of the additive to be added to the fuel is determined based on a property of the fuel.   The fuel supply device according to any one of claims 1 to 3, wherein the additive is a knock resistance improving agent that improves a knock resistance performance of the fuel.   6. The fuel supply apparatus according to claim 5, wherein an amount of the knock resistance improving agent to be introduced to the fuel is determined based on a knock resistance performance of the fuel.   The fuel supply device according to any one of claims 1 to 3, wherein the additive is an ignitability improver that improves the ignitability of the fuel.   The fuel supply device according to claim 7, wherein an input amount of the ignitability improver for the fuel is determined based on an ignitability of the fuel.   An internal combustion engine, wherein the fuel is supplied by the fuel supply device according to any one of claims 1 to 8.

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