JP2010180765A - Control device of internal combustion engine - Google Patents

Abstract

An accurate fuel property determination is performed at an early stage by promoting homogenization of fuel properties in a fuel tank and a fuel supply path.
Whether or not refueling has been detected is detected (step S001), and the kinetic energy of the fuel flowing through the refueling pipe at the time of refueling is used to rotate the turbine provided in the refueling pipe, thereby being connected to the turbine. The agitator 25 is driven to agitate the fuel in the fuel tank, and the fuel pump is driven in accordance with the detection result of refueling to circulate the fuel in the fuel supply path that connects the fuel tank and the fuel injection valve ( Step S003). Thereby, the homogenization of the property of the fuel in a fuel tank and a fuel supply path can be promoted. Thus, after homogenizing the fuel properties, the fuel properties are determined (step S004).
[Selection] Figure 3

Description

  The present invention relates to a control device for an internal combustion engine, and more particularly to control of an internal combustion engine that can complete fuel property determination after refueling early without erroneous detection with respect to detection of fuel properties that have a large effect on combustion fluctuations of the internal combustion engine. Relates to the device.

  In recent years, in order to improve fuel efficiency, there is an increasing need for operation with an air-fuel ratio of an internal combustion engine diluted with respect to a theoretical air-fuel ratio. However, when the air-fuel ratio is diluted, when a fuel containing a mixture of many types of hydrocarbons such as gasoline is used, the state of the combustible mixture varies depending on the properties of gasoline and the deterioration or fluctuation of combustion occurs. It is known to be susceptible to The fuel properties of commercially available gasoline differ depending on the type of gasoline, and also differ depending on the region and season, and detection of fuel properties is essential to suppress problems such as combustion fluctuations.

  Therefore, a method for determining fuel properties from the difference in control variables such as the in-cylinder pressure state during combustion and the fuel correction coefficient has been proposed as a known technique, but transient states such as acceleration / deceleration during operation of the internal combustion engine are proposed. In many cases, in-cylinder pressure and control variables change due to factors other than fuel properties, and it is difficult to detect fuel properties. Further, as a method for detecting the fuel property immediately after start-up that is unlikely to be in a transient state, for example, in Patent Document 1 below, the rotational speed and the time until the peak of the rotational speed that differ depending on the fuel property are preset. A method for determining the fuel property by comparing with the comparison value is shown. However, the fuel before refueling remains in the fuel supply path and the fuel header immediately after refueling, not the newly refueled fuel. Therefore, when the fuel property of the residual fuel is determined instead of the new fuel, and the residual fuel is consumed during the operation of the internal combustion engine, the fuel property suddenly changes to the new fuel property, and combustion deterioration occurs.

  Therefore, in recent years, as an alcohol mixed fuel in which alcohol such as ethanol is mixed with gasoline, which has been attracting attention as an alternative fuel for gasoline in internal combustion engines, as a method for homogenizing the fuel during refueling, It is shown that the fuel pump is driven by the refueling operation detection signal, the fuel property in the fuel supply path is homogenized to the fuel property in the fuel tank, and then the fuel property is detected.

JP-A-3-26841 Japanese Utility Model Publication No. 5-66261

  However, the technique according to Patent Document 2 is homogenization using only the fuel pump, and the fuel in the fuel tank is not actively agitated. Therefore, the fuel properties in the fuel tank cannot be homogenized at an early stage. As a result, accurate fuel property determination is difficult at an early stage. Further, since the fuel pump is continuously driven during refueling in which the internal combustion engine is stopped in a state where the fuel pressure in the fuel supply path is high, there is a problem that the power consumption of the battery increases.

  The present invention has been made to solve such a problem, and by promoting the homogenization of fuel properties in the fuel tank and the fuel supply path, accurate fuel property determination can be performed at an early stage. It is an object of the present invention to obtain a possible control device for an internal combustion engine.

  The present invention relates to a control device for an internal combustion engine provided with a fuel supply detection means for detecting fuel supply to a fuel tank supplied from a fuel supply port, and a fuel property determination means for determining the property of the fuel. And a fuel supply path homogenizing means for homogenizing the fuel properties in a fuel supply path for supplying fuel from the fuel tank to a fuel injection valve. When the detecting means detects refueling, the fuel property determining means homogenizes the fuel property in the fuel tank by the in-tank homogenizing means, and the fuel in the fuel supply path by the supply path homogenizing means. A control device for an internal combustion engine, characterized in that fuel properties are determined after the properties are homogenized.

  The present invention relates to a control device for an internal combustion engine provided with a fuel supply detection means for detecting fuel supply to a fuel tank supplied from a fuel supply port, and a fuel property determination means for determining the property of the fuel. And a fuel supply path homogenizing means for homogenizing the fuel properties in a fuel supply path for supplying fuel from the fuel tank to a fuel injection valve. When the detecting means detects refueling, the fuel property determining means homogenizes the fuel property in the fuel tank by the in-tank homogenizing means, and the fuel in the fuel supply path by the supply path homogenizing means. Since the control device for an internal combustion engine is characterized in that the fuel property is determined after the property is homogenized, the homogenization of the fuel property in the fuel tank and the fuel supply path is promoted. , It is possible to perform an accurate fuel property determination at an early stage.

It is a schematic block diagram which shows the structure of the control apparatus of the internal combustion engine which concerns on this invention. 1 is a schematic configuration diagram showing a configuration of a fuel system device of an internal combustion engine according to the present invention. It is a flowchart used as the main body of Embodiment 1 and Embodiment 2 of this invention. It is a flowchart used for the oil supply detection calculation of Embodiment 1 of this invention. It is a flowchart used for the fuel pump drive calculation of Embodiment 1 of this invention. It is a flowchart used for the fuel property determination calculation of Embodiment 1 and Embodiment 2 of this invention. It is a flowchart used for the oil supply detection calculation of Embodiment 2 of this invention. It is a flowchart used for the fuel pump drive calculation of Embodiment 2 of this invention.

  In addition to the above-described lean combustion internal combustion engine, as an internal combustion engine that is susceptible to combustion fluctuations due to differences in fuel properties, an alcohol internal combustion engine that uses an alcohol-mixed fuel in which alcohol such as ethanol is mixed with gasoline is used as an alternative fuel for gasoline. However, in the present invention, an internal combustion engine capable of performing high-efficiency and ultra-low NOx compression self-ignition combustion, which is attracting attention as an internal combustion engine corresponding to future automobile exhaust gas regulations, is taken as an example. Compressed self-ignition combustion of a combustible mixture is a phenomenon mainly governed by the temperature of the combustible mixture, and it is achieved by increasing the compression of the combustible mixture in advance in the compression stroke of the Otto cycle. The combustible gas mixture is ignited by itself when the compression is completed, which is a condition for the combustible gas mixture to self-ignite. When using a fuel mixed with many types of hydrocarbons, such as gasoline, the temperature of self-ignition of the combustible mixture varies depending on the fuel properties, and combustion fluctuations occur. Become.

  FIG. 1 is an overall schematic diagram showing the configuration of a control device for an internal combustion engine according to Embodiments 1 and 2 of the present invention. FIG. 2 shows the configuration of a fuel system device for the internal combustion engine. FIG. A basic configuration related to the present invention will be described with reference to these drawings. In FIG. 1, 6 is an engine body. The engine 6 has an intake port for intake of air and an exhaust port for exhausting combustion gas (exhaust gas) after combustion. An intake pipe 5 is connected to the intake port, and an exhaust pipe 30 is connected to the exhaust port. The intake port and the exhaust port are provided with an intake valve 31 and an exhaust valve 32, respectively, so that each port is opened and closed.

  An air filter 1, an air flow sensor 2, a throttle valve 3, and an intake air temperature control device 4 are connected to the intake pipe 5. The air filter 1 is an air filter that removes dust contained in the air sucked into the engine 6. The air flow sensor 2 is composed of, for example, a hot-wire air flow sensor, and generates a voltage signal corresponding to the mass flow rate of intake air. The throttle valve 3 is linked to an accelerator pedal (not shown) and adjusts the intake air amount. Further, the throttle valve 3 is provided with, for example, a potentiometer and a throttle valve opening sensor 11 for detecting the throttle valve opening. The intake air temperature control device 4 is connected to an intake port of the engine 6 through an intake pipe 5, and based on a control signal from an ECU (Engine Control Unit) 19 described later, an operating point, fuel properties, etc. The intake air temperature is controlled according to.

  The intake pipe 5 is provided with a fuel header 10. One fuel injection valve 7 attached to the fuel header 10 is arranged for each cylinder of the engine 6, and as shown in FIG. The fuel injection valve 7 injects fuel according to a signal from the drive circuit 18, and the injected fuel and the air flowing in from the intake pipe 5 are mixed in the combustion chamber 9 of the engine 6 to form an air-fuel mixture. Is done. The air-fuel mixture is compressed self-ignited combustion in a predetermined operation region determined by the engine speed and load, which can be self-ignited, while it is attached to the engine 6 in an operation region where compression self-ignition is difficult. It is ignited by the spark plug 8 and burns.

  As shown in FIG. 1, the control device for the internal combustion engine is provided with a crank angle sensor 12 and a cam angle sensor 13. A crankshaft (not shown) is provided under the engine 6, and the crank angle sensor 12 outputs a pulse signal every time the crankshaft rotates a certain amount. A camshaft (not shown) for opening and closing the intake valve 31 and the exhaust valve 32 in accordance with the intake and exhaust timing is provided above the engine 6. The camshaft and the crankshaft are connected by a timing belt (not shown), and the rotation of the crankshaft is transmitted to the camshaft by belt transmission. The cam angle sensor 13 outputs a pulse signal every time the cam shaft of the engine 6 rotates at a constant speed. In this configuration, for example, the crank angle sensor 12 outputs a rotation angle detection pulse every 10 ° of the crank rotation angle. Since the cam angle sensor 13 outputs a different signal for each cylinder, the cylinder can be specified in combination with the signal of the crank angle sensor 12.

  On the other hand, the ECU 19 provided in the passenger compartment or the like is a microcomputer system that executes various controls, and includes an input / output interface 17, a central processing unit 14, a ROM 15, a RAM 16, and a drive circuit 18. Various sensors and switches are connected to the input side of the ECU 19, and outputs from these various sensors are A / D converted via the input / output interface 17 and taken into the ECU 19. The ECU 19 performs arithmetic processing based on the input signal. The ECU 19 outputs control signals for various actuators based on the calculation result, and controls actuators such as the fuel injection valve 7 and the spark plug 8.

  Next, the configuration and function of the fuel system that is the main component of the first and second embodiments of the present invention will be described with reference to FIG. The fuel supplied from the fuel supply port 20 through the fuel supply pipe 23 is stored in the fuel tank 21, and the amount of fuel in the fuel tank 21 is detected by the fuel tank gauge 22. The ECU 19 can detect the start of refueling, during refueling, or the end of refueling based on the change in the detected value of the remaining amount of fuel by the fuel tank gauge 22 (refueling detecting means). That is, if the amount of fuel in the fuel tank 21 increases, it can be detected that refueling has started, and while the state continues, refueling is in progress. When the increase in the amount of fuel in the fuel tank 21 stops, the end of refueling is detected. it can. A turbine 24 is provided in the oil supply pipe 23, and a stirrer 25 is provided so as to be disposed in the combustion tank 21. The stirrer 25 and the turbine 24 are connected by a connecting shaft, and the stirrer 25 also rotates in accordance with the rotation of the turbine 24. When refueling, the turbine 24 is rotated by the kinetic energy of the fuel flowing through the fuel supply pipe 23, whereby the agitator 25 provided in the fuel tank 21 is driven and the fuel in the fuel tank 21 is agitated. Thereby, homogenization of the fuel property in the fuel tank 21 is promoted. Further, by opening the electromagnetic valve 26 and the electromagnetic valve 27 provided for the fuel supply path 28 that connects the fuel tank 21 and the fuel header 10 provided with the fuel injection valve 7, Residual fuel is extracted, and the fuel pump 29 is driven by a signal from the drive circuit 18 to circulate the fuel from the fuel tank 21 into the fuel supply path 28 and the fuel header 10 to homogenize the fuel properties. After being homogenized in this way, the ECU 19 determines the fuel property (fuel property determination means). The determination of the fuel property depends on the difference in the fuel property, so that the speed increase immediately after starting the internal combustion engine (that is, the maximum rotation speed) differs. Based on this value, the fuel in the fuel tank 21 is the standard fuel. Or heavy fuel. In the present invention, fuel determination is performed with high accuracy using the homogenized fuel in this manner, and the occurrence of problems due to combustion fluctuations of the internal combustion engine is prevented. The fuel pump 29 incorporates a fuel pressure regulator (not shown) for adjusting the fuel pressure. When the internal combustion engine is started, the fuel pump 29 is driven, the fuel in the fuel tank 21 is pumped up, and is pumped to the fuel supply header 10 via the fuel supply path 28. The fuel pressure regulator incorporated in the fuel pump 29 causes the fuel header 10 to have a predetermined fuel pressure from the fuel pump 29, and the fuel injection valve 7 is driven according to a signal from the drive circuit 18.

  If comprised as mentioned above, the homogenization of the fuel property in a fuel tank and a fuel supply path can be accelerated | stimulated, and accurate fuel property determination can be performed at an early stage.

  Thus, in the present invention, the in-tank homogenizing means for promoting the homogenization of the fuel properties in the fuel tank 21 is provided. The in-tank homogenizing means is provided in the vicinity of the oil supply port 23 and is rotated by the connecting shaft to the turbine 24 that rotates by the kinetic energy of the oil flowing through the oil supply pipe 23, and is driven in accordance with the rotation of the turbine 24. The agitator 25 disposed in the fuel tank 21 is driven, and the agitator 25 disposed in the fuel tank 21 is driven by the rotation of the turbine 24 at the time of refueling. Promote homogenization.

  In the present invention, the ECU 19 includes supply path homogenizing means for promoting homogenization of the fuel properties of the fuel supply path. The supply path homogenizing means has a fuel pump control means and an electromagnetic valve control means. The fuel pump control means drives the fuel pump 29 to circulate the fuel in the fuel supply path 28 when the fuel supply detection means of the ECU 19 detects that there is fuel supply, and homogenizes the fuel properties in the fuel supply path 28. Promote. The electromagnetic valve control means controls the opening and closing of the electromagnetic valves 26 and 27 that are opened to return the fuel in the fuel supply path 28 to the fuel tank 21. When the refueling detection means of the ECU 19 detects the start of refueling, the solenoid valve control means opens the solenoid valves 26 and 27 to return the fuel in the fuel supply path 28 to the fuel tank 21, and in the fuel supply path 28. Drain the remaining fuel. Thereby, when fuel is circulated through the fuel supply path 28 by the fuel pump 29, homogenization of the fuel properties in the fuel supply path 28 is promoted.

Embodiment 1 FIG.
Hereinafter, specific contents of the first embodiment of the present invention will be described. The configuration of the control device for the internal combustion engine and the configuration of the fuel system device according to the first embodiment are as described with reference to FIG. 1 and FIG. 2 described above. Omitted.

  As described above, in the first embodiment, when refueling is performed from the refueling port 20, the turbine 24 provided in the refueling pipe 23 is rotated using the kinetic energy of the refueling fuel so that it is provided in the fuel tank 21. The stirrer 25 is driven, thereby agitating the fuel in the fuel tank 21 to promote homogenization of the fuel properties of the fuel supply and the remaining fuel. Further, by opening the solenoid valves 26 and 27 provided in the fuel supply path 28 to return the fuel in the fuel supply path 28 to the fuel tank 21, the fuel pump 29 is driven to drive the fuel supply path 28. The fuel in the fuel supply path 28 is homogenized at an early stage so as to have the same properties as the fuel in the fuel tank 21. In this way, in the first embodiment, the homogenization of the fuel properties in the fuel tank 21 and the fuel supply path 28 is promoted, and the property determination can be performed with the homogenized fuel, so that it can be done early. Accurate fuel properties can be implemented.

  FIG. 3 shows a control routine executed by the ECU 19 which is the main body of the first embodiment, and FIGS. 4, 5 and 6 show a control routine which is the next to the control routine of FIG. First, the main control routine of the first embodiment will be described with reference to FIG. 3, and the subsequent control routine will be described in order.

  In the control apparatus for an internal combustion engine according to the first embodiment, as shown in FIG. 3, first, in step S001, a refueling detection calculation related to refueling detection shown in FIG. 4 is executed, and then in step S003, The fuel pump drive calculation related to the homogenization of the fuel properties in the fuel supply path 28 shown in FIG. 5 is executed, and then the fuel property determination calculation related to the determination of the fuel properties shown in FIG. 6 is executed in step S004. .

  Details of the refueling detection calculation in step S001 of FIG. 3 will be described with reference to FIG. The refueling detection calculation in step S001 of FIG. 3 is executed by the refueling detection means provided in the ECU 19 according to the process flow shown in FIG. In the refueling detection calculation, as shown in FIG. 4, first, in step S101, the presence / absence of refueling is determined by increasing or decreasing the detected value of the fuel amount by the fuel tank gauge 22 when refueling. At this time, if refueling cannot be detected, it has not been refueled or after refueling is completed, the detection flag is cleared in step S108, and the process returns to the main control routine of FIG. On the other hand, if it is detected in step S101 that there is refueling, it is next determined in step S102 whether the detection flag is set. If not, refueling is started, so in step S103. Set the detection flag. In addition, the initialization process is mainly considered after step S103, and the process is performed only once immediately after the start of refueling. If refueling is detected in step S101, the fuel properties become inhomogeneous between the residual fuel originally in the fuel tank 21 and the newly refueled fuel due to fuel refueling. The property determination completion flag is cleared, and in step S105, the fuel property homogenization flag is cleared. Next, in step S106, the solenoid valve 26 and the solenoid valve 27 provided in the fuel supply path 28 are opened to return the fuel remaining in the fuel supply path 28 to the fuel tank 21, and in step S107, the solenoid valve 26 is opened. The solenoid valve 26 open timer (not shown) for confirming the waiting time is reset, and the process returns to the main control routine of FIG. The solenoid valve 26 open timer counts up immediately after the start of refueling and is held at the maximum value until refueling. On the other hand, if the detection flag is set in step S102, the initialization process at the start of refueling is completed, and the process returns to the main control routine of FIG.

  Next, details of the fuel pump drive calculation in step S003 of FIG. 3 will be described with reference to FIG. The fuel pump drive calculation in step S003 of FIG. 3 is executed by the fuel pump control means provided in the ECU 19 according to the process flow shown in FIG. In the fuel pump drive calculation, as shown in FIG. 5, first, in step S301, it is determined whether or not a detection flag signifying refueling is set. In S302, it is confirmed whether or not a solenoid valve 26 open timer indicating a time during which the solenoid valve 26 is open is longer than 1 second. In the first embodiment, the comparison value of the time during which the solenoid valve 26 is opened is 1 second. However, this time is taken into consideration for the shape and length of the fuel supply path 28 and the fuel header 10, and the residual fuel is removed from the fuel tank. The minimum time that can be returned to 21 is set as appropriate. If it is 1 second or less in step S302, the residual fuel remains, so the process returns to the main control routine of FIG.

  On the other hand, if it is longer than 1 second, it means that no residual fuel remains. Therefore, in step S303, the electromagnetic valve 26 is closed, and in step S304, the fuel properties of the fuel supply path 28 and the fuel header 10 are homogenized. The fuel pump 29 is driven to circulate the fuel from the fuel tank 21 to the fuel supply path 28, the fuel header 10, and the fuel supply pipe 23 in order. On the other hand, if the detection flag is not set in step S301, the fuel has not been supplied or has just been completed, and the fuel properties in the fuel tank 21 and the fuel supply path 28 are sufficiently homogenized. Therefore, in step S305, the fuel pump 29 is stopped, and in preparation for the start of the internal combustion engine, the electromagnetic valve 26 and the electromagnetic valve 27 are closed in step S306 so that the fuel pressure becomes a desired pressure. Next, in step S307, the current state is a state in which the fuel properties in the fuel tank 21 and the fuel supply path 28 are homogenized, so the homogenization flag is set and the main control routine of FIG. Return.

  Finally, details of the fuel property determination calculation in step S004 of FIG. 3 will be described with reference to FIG. The fuel property determination calculation in step S004 of FIG. 3 is executed by the fuel property determination means provided in the ECU 19 according to the process flow shown in FIG. In the fuel property determination calculation, first, it is cleared in the initialization process immediately after the start of refueling in step S401, and it is determined whether the fuel property determination completion flag set at the time of fuel property determination is cleared. Since the fuel property has changed due to refueling, the process proceeds to step S402, and it is determined whether the homogenization flag that is set when the fuel properties in the fuel tank 21 and the fuel supply path 28 are homogenized is set. To do. If it is set, the fuel property is homogenized and the fuel property determination can be executed without erroneous determination. Therefore, in the processing from step S403 to step S407, the rotational speed immediately after startup due to the difference in fuel property is increased, That is, the fuel property is determined from the difference in the maximum rotation speed.

  When the standard fuel is used, the maximum rotational speed is higher in the combustion state and higher than when the heavy fuel is used. Therefore, in step S403, it is determined whether or not it is a predetermined section after starting. As the predetermined section, a section in which the rotation speed immediately after start-up, that is, a section in which the maximum rotation speed appears, is set in advance. If it is not the predetermined section, the process returns to the main control routine of FIG. If it is a predetermined section, in step S404, the maximum rotation speed is compared with the comparison value. As the comparison value, an average value of the maximum rotation speed when the standard fuel is used and the maximum rotation speed when the heavy fuel is used is set in advance. If the maximum rotation speed is higher than the comparison value as a result of the comparison in step S404, it is determined as standard fuel in step S405. On the other hand, if it is lower than the comparison value, it is determined as heavy fuel in step S406. Finally, in step S407, a property determination completion flag indicating completion of fuel property determination is set, and the process returns to the main control routine of FIG. On the other hand, if it is determined in step S401 or step S402 that the fuel property cannot be determined, the process returns to the main control routine of FIG. 3 without performing the subsequent processing.

  As described above, in the first embodiment, the fuel tank 21 is agitated by the kinetic energy of the fuel supplied during refueling, and the fuel in the fuel supply path 28 and the fuel header 10 is returned to the fuel tank 21. By circulating the fuel through the supply path 28 and the fuel header 10, compared with the case where the fuel pressure in the fuel supply path 28 and the fuel header 21 is circulated at a high level, the power consumption of the battery is suppressed and the fuel properties are homogenized. And accurate fuel property determination can be executed at an early stage.

  That is, in the first embodiment, the ECU 19 detects the fuel supply to the fuel tank supplied from the fuel filler port, the fuel property determination means for determining the fuel property, and the fuel property in the fuel tank. The fuel property judging means comprises: a tank homogenizing means for promoting the homogenization of the fuel; and a supply path homogenizing means for promoting the homogenization of the fuel property of the fuel supply path. Since the fuel property in the fuel tank 21 is homogenized by the in-tank homogenizing means and the fuel property in the fuel supply path 28 is homogenized by the supply path homogenizing means, the fuel property is determined. It is possible to promote homogenization of fuel properties in the fuel supply passage 21 and the fuel supply path 28, and to perform accurate fuel property determination at an early stage.

  The tank homogenization means includes a turbine 24 provided in a fuel supply pipe 23 provided between the fuel supply port 20 and the fuel tank 21, and a stirrer 25 connected to the turbine 24 and provided in the fuel tank 21. The stirrer 25 is driven by the turbine 24 turning by the kinetic energy of the fuel flowing through the oil supply pipe 23 during refueling. The in-tank homogenization means drives the agitator 25 by the rotation of the turbine 24 during refueling to agitate the fuel in the fuel tank 21 to promote homogenization of the fuel properties. By using energy, it is possible to promote homogenization of the fuel properties in the fuel tank 21 while suppressing the power consumption of the battery.

  The supply path homogenizing means has a fuel pump control means and an electromagnetic valve control means. The fuel pump control means drives the fuel pump 29 when the fuel supply detection means of the ECU 19 detects fuel supply, thereby circulating the fuel through the fuel supply path 28 and homogenizing the fuel properties in the fuel supply path 28. Facilitate. The electromagnetic valve control means controls the opening and closing of the electromagnetic valves 26 and 27 that are opened to return the fuel in the fuel supply path 28 to the fuel tank 21. When the refueling detection means of the ECU 19 detects the start of refueling, the solenoid valve control means opens the solenoid valves 26 and 27 to return the fuel in the fuel supply path 28 to the fuel tank 21, and in the fuel supply path 28. Drain the remaining fuel. Thereby, when fuel is circulated through the fuel supply path 28 by the fuel pump 29, homogenization of the fuel properties in the fuel supply path 28 is promoted. In this way, the solenoid valve control means opens the solenoid valves 26 and 27 to return the fuel in the fuel supply path 28 to the fuel tank 21 and withdraws the fuel in the fuel supply path 28. Compared with the state where the fuel in the fuel supply path 28 remains and the fuel pressure is high, the power consumption of the battery required for fuel circulation can be suppressed.

Embodiment 2. FIG.
The second embodiment of the present invention will be described below. Although the content is basically the same as that of the first embodiment described above, the second embodiment is different in that the power consumption of the battery is suppressed by setting the effective driving time of the fuel pump. The configuration of the control device for the internal combustion engine and the configuration of the fuel system device according to the second embodiment are as described with reference to FIG. 1 and FIG. 2 described above. Description is omitted.

  Also in the second embodiment, the control routine executed by the ECU 19 as a main body is basically the same as the control routine of FIG. 3 described in the first embodiment. Hereinafter, each step of the control routine of FIG. 3 according to the second embodiment will be described with reference to FIGS. In the second embodiment, the processing flow of the fuel property determination calculation in step S004 in FIG. 3 is the same as that in the first embodiment described above, and the description thereof is omitted here. Therefore, in the following, the fuel supply detection calculation in step S001 and the fuel pump drive calculation in step S003 of FIG. 3 will be described in detail.

  First, the refueling detection calculation in step S001 of FIG. 3 will be described based on FIG. In the second embodiment, the refueling detection calculation in step S001 of FIG. 3 is executed by the refueling detection means provided in the ECU 19 according to the process flow shown in FIG. That is, in the second embodiment, in the refueling detection calculation, as shown in FIG. 7, first, in step S501, it is determined whether refueling is detected, and if detected, in step S502, which will be described later. A drive timer (not shown) indicating the drive time of the fuel pump 29 used for the drive condition of the fuel pump 29 in the fuel pump drive calculation is reset. The drive timer counts up from the completion of refueling and is held at the maximum value until refueling. The processing from step S503 to step S507 is an initialization process immediately after the start of refueling, similar to the first embodiment described above. First, if the detection flag is not set in step S503, the detection flag is set in step S504. Next, in step S505, the fuel property determination completion flag is cleared, and in step S506, the fuel property homogenization flag is cleared. In step S507, the solenoid valve 26 and the solenoid valve 27 provided in the fuel supply path 28 are opened, and the process returns to the main control routine of FIG. On the other hand, if the detection flag is set in step S503, the initialization process at the start of refueling is completed, and the process returns to the main control routine of FIG.

  On the other hand, if refueling is not detected in step 501, it is determined in step S508 whether the detection flag is set. If the detection flag is not set, that is, if fueling is not in progress, in step S509, the amount of fuel in the fuel tank 21 detected by the fuel tank gauge 22 is stored in the RAM 16 as the remaining amount of fuel before fueling. In step S510, the detection flag indicating refueling is cleared, and the process returns to the main control routine of FIG.

  On the other hand, if the detection flag is set in step S508 even though refueling is not detected in step S501, this indicates immediately after refueling is completed, so the process proceeds to step S511, and will be described later with reference to FIG. The amount of fuel used for the drive condition of the fuel pump 29 in the fuel pump drive calculation is calculated. Specifically, the fuel tank gauge 22 detects the fuel amount (current remaining amount) in the fuel tank 21 when refueling is completed, and the fuel amount and the fuel amount recorded before refueling in step S509 (remaining amount before refueling). The amount of fuel supply is calculated from the difference from the amount) (fuel supply amount = current remaining amount−remaining amount before refueling). After calculating the amount of oil supply in step S511, the process proceeds to step S510, the detection flag is cleared, and the process returns to the main control routine of FIG.

  Next, details of the fuel pump drive calculation in step S003 of FIG. 3 will be described with reference to FIG. In the second embodiment, the fuel pump drive calculation in step S003 of FIG. 3 is executed by the fuel pump control means provided in the ECU 19 according to the process flow shown in FIG. That is, in the second embodiment, in the fuel pump drive calculation, as shown in FIG. 8, first, in step S601, it is determined whether or not a detection flag meaning refueling is set. Since it is in the fuel supply state, the fuel pump 29 is stopped in step S602, and the process returns to the main control routine of FIG. On the other hand, if the detection flag is not set in step S601, it is determined in steps S603 and S604 whether or not it is necessary to circulate the fuel in the fuel supply path 28, thereby driving and stopping the fuel pump 29. Execute. First, in step S603, it is determined whether the difference between the amount of fuel calculated in the fuel supply detection calculation of FIG. 7 and the remaining amount of fuel before fueling is greater than a predetermined amount set to twice the remaining amount of fuel. If it is determined in step S603 that the amount is greater than the predetermined amount, the amount of fuel supply is large, that is, the kinetic energy of the fuel supply fuel is large, the fuel tank 21 is sufficiently agitated, and the fuel properties are homogenized. Further, the fuel in the fuel supply path 28 is almost returned to the fuel tank 21 by opening the solenoid valve 26 and the solenoid valve 27 in the fuel supply detection calculation of FIG. 7, and the returned fuel is sufficiently stirred in the fuel tank 21. Therefore, it is not necessary to circulate the fuel supply path 28. Therefore, if it is determined in step S603 that the difference between the fuel amount and the remaining fuel amount before fueling is greater than the predetermined amount, the electromagnetic valve 26 and the electromagnetic valve 27 are closed in step S607, and the fuel pump 29 is stopped in step S608. In step S609, the homogenization flag is set, and the process returns to the main control routine of FIG. In the second embodiment, the predetermined amount is set to be twice the remaining fuel amount, but may be set as appropriate as long as the fuel property in the fuel tank 21 is sufficiently homogenized.

  On the other hand, if it is determined in step S603 that the difference between the fuel supply amount and the remaining fuel amount before fuel supply is less than the predetermined amount, the homogenization of the fuel properties by the agitator 25 in the fuel tank 21 is insufficient. Then, it is necessary to drive the fuel pump 29 and circulate the fuel through the fuel supply path 28, the fuel header 10, and the fuel supply pipe 23 in order from the fuel tank 21. Therefore, in step S604, the drive timer of the fuel pump 29 is compared with a predetermined time, and if it is shorter than the predetermined time, the fuel property is inhomogeneous, so that in order to circulate the fuel, the solenoid valve is used in step S605. 26 is closed, the fuel pump 29 is driven in step S606, and the process returns to the main control routine of FIG. Note that the predetermined time is set in advance from the experimental results, the performance of the fuel pump 29, and the like, so that the fuel in the fuel tank 21 and the fuel supply path 28 is homogenized in advance, and the driving time of the fuel pump 29 is set longer than necessary. Increase in battery power consumption due to driving is suppressed. In the second embodiment, the predetermined time is used, but a predetermined amount corresponding to the predetermined time may be set.

  On the other hand, if the drive timer is longer than the predetermined time in step S604, the fuel in the fuel supply path 28 is sufficiently circulated and homogenized, so that the electromagnetic valve 26 and the electromagnetic valve 27 are closed in step S607, and step S608 is performed. In step S609, the homogenization flag is set, and the process returns to the main control routine of FIG.

  As described above, in the second embodiment, the fuel tank 21 is agitated by the kinetic energy of the fuel supplied during refueling, and further, the fuel pump 29 is considered in consideration of the necessity of homogenizing the fuel in the fuel supply path 28. Therefore, it is possible to accelerate the homogenization of the fuel property while suppressing the power consumption of the battery more efficiently, and to execute the accurate fuel property determination earlier.

  That is, also in the second embodiment, as in the first embodiment described above, the ECU 19 detects the fuel supply to the fuel tank supplied from the fuel filler and the fuel property for determining the fuel property. A determination unit; a tank homogenization unit that promotes homogenization of fuel properties in the fuel tank; and a supply path homogenization unit that promotes homogenization of fuel properties in the fuel supply path. When detected, the fuel property determining means homogenizes the fuel property in the fuel tank 21 by the in-tank homogenizing means, homogenizes the fuel property in the fuel supply path 28 by the supply path homogenizing means, and then the fuel property. Therefore, the homogenization of the fuel properties in the fuel tank 21 and the fuel supply path 28 can be promoted, and accurate fuel property determination can be executed at an early stage.

  Further, a turbine 24 provided in a fuel supply pipe 23 provided between the fuel supply port 20 and the fuel tank 21, and a stirrer 25 connected to the turbine 24 and provided in the fuel tank 21 are further provided. The stirrer 25 is driven when the turbine 24 is rotated by the kinetic energy of the fuel flowing in the fuel supply pipe 23 during refueling, and the in-tank homogenizer drives the stirrer 25 by the rotation of the turbine 24 during refueling. Since the homogenization of the fuel property in the fuel tank 21 is promoted, the homogenization of the fuel property in the fuel tank 21 can be promoted while suppressing the power consumption of the battery by using the kinetic energy of the fuel supply fuel.

  Further, electromagnetic valves 26 and 27 are provided in the fuel supply path 28 and return the fuel in the fuel supply path 28 to the fuel tank when the fuel supply path 28 is opened, and an electromagnetic valve control means for the ECU 19 to control opening and closing of the electromagnetic valves 26 and 27. And the solenoid valve control means opens the solenoid valves 26 and 27 to return the fuel in the fuel supply path 28 to the fuel tank 21 when the fuel supply detection means detects the start of fuel supply. The fuel in the supply path 28 can be removed, and the power consumption of the battery required for fuel circulation can be suppressed as compared with a state in which the fuel in the normal fuel supply path 28 remains and the fuel pressure is high.

  Further, in the present second embodiment, a drive timer for measuring the drive time of the fuel pump 29 from the end of refueling is further provided, and after the supply path homogenizing means detects the end of refueling by the refueling detection means, By driving the fuel pump 29 until the measurement time of the drive timer reaches a predetermined time, the fuel is circulated through the fuel supply path 28 and the fuel properties in the fuel supply path 28 are homogenized. When the fuel pump 29 is driven for a predetermined time after the detection of the above, homogenization of the fuel properties in the fuel supply path 28 can be promoted while minimizing the power consumption of the battery.

  In addition, the ECU 19 detects a remaining amount of fuel in the fuel tank 21, a refueling amount detecting unit that detects a refueling amount to the fuel tank 21 supplied from the refueling port 23, and before refueling Fuel amount storage means for storing the remaining fuel amount in the fuel tank 21 in the RAM 16 and detected by the remaining fuel amount in the fuel tank 21 stored in the remaining amount storage means and the refueling amount detection means. If the difference between them is less than or equal to the predetermined amount, the fuel properties are homogenized by the supply path homogenizing means. If the difference is greater than the predetermined amount, the supply path is homogenized. Since the fuel property is not homogenized by the fuelizing means, the remaining fuel amount in the fuel tank 21 before refueling and the amount of fuel are compared, and the fuel supply path 28 is not homogenized more than necessary. Efficient fuel pump 29 It can be driven.

  DESCRIPTION OF SYMBOLS 1 Air filter, 2 Air flow sensor, 3 Throttle valve, 4 Intake temperature control apparatus, 5 Intake pipe, 6 Engine, 7 Fuel injection valve, 8 Spark plug, 9 Combustion chamber, 10 Fuel header, 11 Throttle valve opening sensor, 12 Crank angle sensor, 13 cam angle sensor, 14 central processing unit, 15 ROM, 16 RAM, 17 input / output interface, 18 drive circuit, 19 ECU, 20 oil supply port, 21 fuel tank, 22 fuel tank gauge, 23 oil supply pipe, 24 turbine, 25 stirrer, 26, 27 solenoid valve, 28 fuel supply path, 29 fuel pump, 30 exhaust pipe, 31 intake valve, 32 exhaust valve, 33 piston.

Claims (6)

A control device for an internal combustion engine, comprising: a fuel supply detection unit that detects fuel supply to a fuel tank supplied from a fuel supply port; and a fuel property determination unit that determines a property of the fuel,
In-tank homogenizing means for homogenizing the fuel properties in the fuel tank;
Supply path homogenizing means for homogenizing the fuel properties in the fuel supply path for supplying fuel from the fuel tank to the fuel injection valve;
When the refueling detection means detects refueling, the fuel property determining means homogenizes the fuel properties in the fuel tank by the in-tank homogenizing means, and in the fuel supply path by the supply path homogenizing means. A control device for an internal combustion engine, wherein the fuel property is determined after the fuel property is homogenized. The in-tank homogenizing means includes
A turbine provided in a fuel supply pipe provided between the fuel filler port and the fuel tank;
A stirrer provided in the fuel tank, connected to the turbine, and driven by turning the turbine by kinetic energy of fuel flowing through the oil supply pipe when refueling;
The homogenization means in the tank performs homogenization of the fuel property by driving the agitator by rotation of the turbine during refueling to agitate the fuel in the fuel tank. The control apparatus for an internal combustion engine according to claim 1. An electromagnetic valve that is provided in the fuel supply path and returns the fuel in the fuel supply path to the fuel tank when opened;
The supply path homogenizing means has an electromagnetic valve control means for opening the electromagnetic valve when the oil supply detecting means detects the start of oil supply and closing the electromagnetic valve after a predetermined time has elapsed. The control apparatus for an internal combustion engine according to claim 1 or 2. A fuel pump for sending fuel from the fuel tank to the fuel supply path;
The said supply path | route homogenization means has a fuel pump control means which drives the said fuel pump, when oil supply is detected by the said oil supply detection means. The control apparatus of the internal combustion engine described in 1. A drive timer for measuring the drive time of the fuel pump from the end of refueling;
5. The internal combustion engine according to claim 4, wherein the supply path homogenizing unit drives the fuel pump until the measurement time of the drive timer reaches a predetermined time after the end of refueling is detected by the refueling detection unit. Engine control device. A remaining amount detecting means for detecting a remaining amount of fuel in the fuel tank;
A fuel amount detecting means for detecting a fuel amount of fuel supplied to the fuel tank supplied from the fuel filler;
Remaining amount storage means for storing the remaining amount of fuel in the fuel tank before refueling,
The supply path homogenizing unit compares the fuel amount detected by the fuel amount detecting unit with the fuel remaining amount in the fuel tank before refueling stored in the remaining amount storing unit, 6. The fuel property is homogenized when the difference is less than a predetermined amount, and the fuel property is not homogenized when the difference is greater than a predetermined amount. The control device for an internal combustion engine according to any one of the above.

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