JP2011208570A - Control apparatus of restarting - Google Patents

Abstract

[PROBLEMS] To suppress the deterioration of fuel efficiency while suppressing the occurrence of self-ignition of an engine mounted on a vehicle.
A restart control device (100) is mounted on a vehicle (1) having an engine (11), and temperature detecting means (21) for detecting the temperature of the engine, and fuel supply capable of supplying fuel to the engine. The engine (115) is configured to start the engine on the condition that the detected temperature is higher than a first predetermined value and the amount of fuel leakage from the fuel supply means is larger than a second predetermined value when the engine is stopped. Control means (20) for controlling the engine.
[Selection] Figure 2

Description

  The present invention relates to a technical field of a restart control device that performs automatic restart control of an engine mounted on a vehicle such as an automobile.

  In this type of apparatus, for example, self-ignition caused by fuel leak can be prevented. For example, Patent Document 1 describes a device that acquires engine water temperature and engine intake air temperature while the engine is stopped, and immediately restarts the engine if the acquired water temperature and intake air temperature are within the auto-ignition generation region. Has been. In particular, it is described that the possibility of the occurrence of self-ignition is influenced by the charging efficiency in addition to the air-fuel ratio of the air-fuel mixture introduced into the combustion chamber of the engine.

  Alternatively, for example, Patent Document 2 discloses a device that restarts an engine by combustion in a stop-time expansion stroke cylinder that is in an expansion stroke when the engine is stopped when a condition for restarting the engine after automatic stop is satisfied. Are listed. Here, in particular, when the in-cylinder temperature of each cylinder is estimated when the engine is stopped and a predetermined warm state is detected, if the measured value of the fuel leak amount is greater than or equal to a predetermined threshold value, the fuel is discharged in the middle of the compression stroke of the cylinder. It is described that the fuel is over-rich by jetting.

JP 2007-120448 A JP 2007-270806 A

  However, in the said patent document 1, the amount of fuel leaks is not considered. Then, even when the amount of fuel leakage is relatively small, there is a technical problem that the engine is frequently started due to the relatively high engine water temperature and the like, and the fuel efficiency may deteriorate. . Moreover, in the said patent document 2, since the fuel is injected in order to suppress generation | occurrence | production of self-ignition, there exists a technical problem that a fuel consumption efficiency may deteriorate.

  This invention is made | formed in view of the said problem, for example, and makes it a subject to propose the restart control apparatus which can suppress deterioration of fuel consumption efficiency, suppressing generation | occurrence | production of self-ignition.

  In order to solve the above problems, a restart control device of the present invention is mounted on a vehicle having an engine, temperature detection means for detecting the temperature of the engine, fuel supply means capable of supplying fuel to the engine, When the engine is stopped, the engine is started so that the detected temperature is higher than a first predetermined value and the amount of fuel leakage from the fuel supply means is larger than a second predetermined value. And control means for controlling.

  According to the restart control device of the present invention, the restart control device is mounted on a vehicle having an engine. Here, the “engine” may take various modes regardless of physical, mechanical or electrical configuration, such as fuel type, fuel supply mode, fuel combustion mode, intake / exhaust system configuration, and cylinder arrangement. . The vehicle is not limited to a vehicle having only an engine, and may be a hybrid vehicle having a motor for driving the vehicle and an engine, for example.

  For example, temperature detection means such as a temperature sensor detects the temperature of the engine. It should be noted that the engine temperature is not limited to being detected directly, but for example, a physical quantity or parameter related to the engine temperature is detected and estimated based on the detected physical quantity or parameter (that is, indirectly) Detection). The “engine temperature” is not limited to the temperature of the engine itself (for example, the temperature in the cylinder), but also includes physical quantities or parameters (for example, cooling water temperature, intake air temperature, etc.) that change in conjunction with the temperature of the engine itself. It's okay.

  For example, fuel supply means such as an injector can supply fuel to the engine. “Supplying fuel to the engine” is not limited to supplying fuel directly into the combustion chamber of the engine (so-called in-cylinder injection) but also supplying fuel to the intake passage of the engine (so-called port injection). May also be included.

  For example, the control means comprising a memory, a processor, etc. is provided on condition that the detected temperature is higher than a first predetermined value and the amount of fuel leakage from the fuel supply means is higher than a second predetermined value when the engine is stopped. And controlling the engine to start it.

  Here, “starting the engine” is not limited to obtaining a normal combustion state in the combustion chamber of the engine, but to move components of the engine toward the operation of the engine (for example, , Cranking the crankshaft of the engine, etc.). That is, it means that the constituent members of the engine are operated regardless of whether or not the engine is finally operated. Further, “controlling the engine” means controlling at least a part of members (for example, a cranking motor, a spark plug, etc.) necessary for engine operation.

  The amount of fuel leakage from the fuel supply means may be determined based on, for example, the fuel pressure that is the pressure applied to the fuel before being injected from the fuel supply means.

  The “first predetermined value” and the “second predetermined value” are values that determine whether or not to control the engine so as to start the engine. The first predetermined value and the second predetermined value are set in advance as fixed values or according to some physical quantity or parameter. It is set as a variable value.

  The first predetermined value and the second predetermined value are obtained experimentally, empirically, or by simulation, for example, by determining a region where self-ignition occurs on two-dimensional coordinates using the engine temperature and the fuel leak amount as parameters, What is necessary is just to set each as the value of the area | region side which self-ignition does not generate | occur | produce only predetermined value from the boundary line (namely, boundary line of the area | region where self-ignition does not occur) of the calculated | required area | region.

  On the other hand, on the condition that the detected temperature is lower than the first predetermined value and / or the fuel leak amount is smaller than the second predetermined value, the control means controls the engine so as not to start the engine. It should be noted that when the detected temperature is “equal” to the first predetermined value and when the fuel leak amount is “equal” to the second predetermined value, they may be included in either of them.

  According to the inventor's research, the following matters have been found. That is, for example, in a vehicle that performs automatic engine stop control when stopping (so-called idling stop control), a hybrid vehicle, or the like, when the engine is restarted, the engine coolant temperature or intake air temperature is equal to or higher than a predetermined value. If the amount of leaked fuel is greater than or equal to a predetermined value, self-ignition occurs in the first compression stroke, and noise and shock may occur.

  In particular, in a vehicle with a relatively low engine operation frequency such as a range extender type hybrid vehicle, there is a possibility that self-ignition may occur due to repeated high-speed operation (that is, travel using the engine and the drive motor). is there. This is because the interval between the engine stop and the next operation is relatively long, the amount of fuel leaked from the injector is relatively large, and the engine temperature is increased by high load operation (ie, high speed operation). This is because the temperature is relatively high.

  However, in the present invention, as described above, on the condition that, when the engine is stopped, the detected temperature is higher than the first predetermined value and the amount of fuel leakage from the fuel supply means is higher than the second predetermined value. The engine is controlled to start the engine.

  Specifically, for example, when the above condition is satisfied, the engine is operated for a relatively short period by the control means. As a result, since the amount of fuel existing in the cylinder of the engine after operation is reduced, it is possible to suppress the occurrence of self-ignition when the engine is started next time. When the vehicle is a hybrid vehicle, when the engine is operated to suppress the occurrence of self-ignition, the deterioration of fuel consumption can be suppressed by rotating the generator with the engine, which is very practical. Is advantageous.

  Alternatively, when the above condition is satisfied, the engine is cranked by the control means (at this time, fuel injection and ignition are not performed). As a result, the fuel present in the cylinder is discharged due to the cranking, so that the occurrence of self-ignition can be suppressed when the engine is started next time.

  In one aspect of the restart control apparatus of the present invention, the control means obtains the fuel leak amount based on the fuel pressure of the fuel.

  According to this aspect, the amount of fuel leakage can be obtained relatively easily, which is very advantageous in practice. Note that “determining” means “estimating” or “calculating” the fuel leak amount by an algorithm or arithmetic expression using the fuel pressure as a parameter, or “specifying” the fuel leak amount from a map using the fuel pressure as a parameter. It is a comprehensive concept that includes

  In another aspect of the restart control apparatus of the present invention, the control means rotates the crankshaft of the engine while controlling the fuel supply means so that the fuel is not supplied when the engine is started. The engine is controlled as follows.

  According to this aspect, since the fuel existing in the cylinder is discharged due to the cranking, it is possible to suppress the occurrence of self-ignition when the engine is started next time. In particular, when the vehicle is a hybrid vehicle, it is possible to increase the period of EV (Electric Vehicle) travel, which can improve fuel consumption and is very advantageous in practice.

  Note that “controlling the engine so that the crankshaft rotates” means, for example, controlling an engine control motor, a cell motor, or the like so that the crankshaft rotates.

  In this aspect, the control means controls the fuel supply means so that the fuel is not supplied when the engine is started, so that the crankshaft rotates while the exhaust valve of the engine is closed. The engine may be controlled.

  If configured in this manner, the fuel in the cylinder is not discharged into the exhaust passage, so that deterioration of emissions can be suppressed, which is very advantageous in practice.

  In an aspect in which the exhaust valve is closed, the control means controls the fuel supply means to supply the fuel on the condition that the amount of fuel in intake air is larger than a third predetermined value, and the engine The engine may be controlled to operate.

  If comprised in this way, when the engine is started next time, the misfire of the engine can be suppressed, which is very advantageous in practice. Note that “the engine is operating” means that a normal combustion state is obtained in the combustion chamber of the engine, or that the engine is in a complete explosion state.

  According to the inventor's research, the following matters have been found. That is, the amount of fuel in the intake system increases due to the fuel in the cylinder being exhausted to the intake side (that is, in the surge tank). If the amount of scavenged fuel to the intake system increases excessively, the amount of fuel in the intake air will exceed the flammable range and become misfired at the next engine start.

  However, in the present invention, as described above, the engine is operated with the control means controlling the fuel supply means to supply the fuel on condition that the amount of fuel in the intake air is larger than the third predetermined value. The engine is controlled. For this reason, since the amount of fuel existing in the cylinder of the engine after operation is reduced, misfire can be suppressed when the engine is started next time.

  Alternatively, in an aspect in which the exhaust valve is closed, the control unit may calculate the amount of fuel to be supplied by the fuel supply unit based on the amount of fuel in the intake air.

  If comprised in this way, when the engine is started next time, the misfire of the engine can be suppressed, which is very advantageous in practice.

  Here, specifically, the control means, for example, changes the fuel amount supplied from the fuel supply means when the engine is started next time (that is, the injection amount at the start) from the original fuel amount into the intake air. Calculated by subtracting the amount of fuel contained. As a result, it is possible to prevent the amount of fuel in the intake air from exceeding the combustible range and becoming excessive at the next engine start.

  In another aspect of the restart control device of the present invention, the vehicle is a hybrid vehicle.

  According to this aspect, since the period during which the hybrid vehicle travels EV can be increased, fuel consumption can be improved while suppressing the occurrence of self-ignition.

  The effect | action and other gain of this invention are clarified from the form for implementing demonstrated below.

It is a block diagram which shows the structure of the vehicle by which the restart control apparatus which concerns on 1st Embodiment is mounted. It is a flowchart which shows the engine restart control process which ECU which concerns on 1st Embodiment performs. It is an example of the map which defines the relationship between intake air temperature and / or water temperature, and predetermined time Tth. (A) is an example of a self-ignition region on a two-dimensional coordinate using the compression end temperature and the in-cylinder fuel amount as parameters, and (b) is a relationship between the elapsed time after the engine is stopped and the in-cylinder fuel amount. (C) is an example of the relationship between water temperature or intake air temperature, and compression end temperature. It is an example of the relationship between time and vehicle speed. It is a flowchart which shows the engine restart control process which ECU which concerns on 2nd Embodiment performs. It is an example of the map which defines the relationship between a fuel pressure and a fuel pressure correction coefficient. It is an example of the relationship between a fuel pressure and the amount of fuel leaks from the direct injection injector per unit time. It is a flowchart which shows the engine restart control process which ECU which concerns on 3rd Embodiment performs. It is an example of the map which defines the relationship between the injector integration injection frequency and the correction coefficient kinjn with the injection frequency. It is a flowchart which shows the engine restart control process which ECU which concerns on 4th Embodiment performs. It is a flowchart which shows the engine restart control process which ECU which concerns on 5th Embodiment performs. It is a flowchart which shows the engine restart control process which ECU which concerns on 6th Embodiment performs. It is an example of the relationship between the number of scavenging times and the integrated value of the scavenged fuel amount. It is a flowchart which shows the engine restart control process which ECU which concerns on 7th Embodiment performs. It is an example of the relationship between the number of scavenging times and the starting injection amount.

  An embodiment of a restart control device according to the present invention will be described with reference to the drawings.

<First Embodiment>
A first embodiment of a restart control device according to the present invention will be described with reference to FIGS. 1 to 5. In the present embodiment, a hybrid vehicle is taken as an example of the “vehicle” according to the present invention.

  First, the configuration of a vehicle on which the restart control device according to this embodiment is mounted will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of a vehicle on which the restart control device according to the present embodiment is mounted. In FIG. 1, dotted lines indicate electrical connection, and alternate long and short dash lines indicate signals. In FIG. 1, for convenience of explanation, only members that are directly related to the present embodiment are shown, and other members are not shown.

  In FIG. 1, a vehicle 1 includes an engine (ENG) 11, motor generators MG1 and MG2, a battery (BAT) 12, a PCU (Power Control Unit) 13, and an ECU (Electronic Control Unit) 20. .

  The engine 11 includes an intake passage 111, an exhaust passage 112, an intake valve 113, an exhaust valve 114, and an injector 115 as an example of the “fuel supply means” according to the present invention. The injector 115 supplies fuel directly into the combustion chamber of the engine 11. That is, the engine 11 is a direct injection engine.

  For example, the battery 12 such as a lithium ion battery can supply power to the motor / generators MG1 and MG2 via the PCU 13, and the regenerative power of the motor / generators MG1 and MG2 is supplied via the PCU 13. It can be charged.

  The motor generator MG1 has a rotor connected to the drive shaft of the engine 11. The motor / generator MG1 generates electric power when the rotor rotates as the drive shaft of the engine 11 rotates. On the other hand, the motor / generator MG1 can crank the engine 11 when electric power is supplied from the battery 12 via the PCU 13.

  The motor / generator MG2 has a rotor connected to a power transmission mechanism. The motor / generator MG2 is supplied with power from the battery 12 or the motor / generator MG1 via the PCU 13, or is supplied with power from the battery 12 and the motor / generator MG1, via the power transmission mechanism. Driving force is output to the driving wheel 14. On the other hand, the motor / generator MG2 also functions as a regenerative brake.

  The vehicle 1 is a series-type hybrid vehicle that uses the engine 11 only for power generation and uses the motor / generator MG2 as a drive source of the hybrid vehicle 1.

  The restart control device 100 includes a temperature sensor 21 that detects the temperature of the engine 11 (for example, the temperature of cooling water, the temperature of intake air, etc.), a pressure sensor 22 that detects a fuel pressure that is a pressure applied to the fuel, and the engine 11. The ECU 20 is configured to start the engine 11 on the condition that the detected temperature is higher than a predetermined value and the amount of fuel leakage from the injector 115 is larger than the predetermined value. Here, the “temperature sensor 21” and the “ECU 20” according to the present embodiment are examples of the “temperature detection unit” and the “control unit” according to the present invention, respectively. In the present embodiment, a part of the ECU 20 for various electronic controls of the vehicle 1 is used as a part of the restart control device 100.

  Next, an engine restart control process executed by the ECU 20 during traveling of the vehicle 1 equipped with the restart control device 100 configured as described above will be described with reference to a flowchart of FIG. This engine restart control process is executed regularly or irregularly or continuously while the vehicle 1 is mainly traveling.

  In FIG. 2, first, the ECU 20 determines whether or not the intake air temperature and / or the water temperature detected by the temperature sensor 21 is equal to or higher than a predetermined value as an example of the “first predetermined value” according to the present invention. (Step S101). When it is determined that the detected intake air temperature and / or water temperature is lower than the predetermined value (step S101: No), the ECU 20 once ends the process.

  When it is determined that the detected intake air temperature and / or water temperature is equal to or higher than a predetermined value (step S101: Yes), the ECU 20 calculates a predetermined time Tth determined by the water temperature or the intake air temperature (step S102). Here, the predetermined temperature Tth is calculated from, for example, a map as shown in FIG. FIG. 3 is an example of a map that defines the relationship between the intake air temperature and / or water temperature and the predetermined time Tth. In FIG. 3, the area on the upper right side of the solid line is a self-ignition area.

  The map shown in FIG. 3 may be constructed as follows, for example. That is, for example, as shown in FIG. 4 (a), the self-ignition region (“self-ignition present” in FIG. 4 (a)) is described on the two-dimensional coordinates using the compression end temperature and the in-cylinder fuel amount as parameters. Specified area). Here, the in-cylinder fuel amount at which self-ignition is generated is found to be about 9 to 18 in terms of air-fuel ratio, according to the research of the present inventor.

  Next, based on the relationship between the elapsed time after the engine stop and the in-cylinder fuel amount as shown in FIG. 4 (b), the self-ignition in FIG. 4 (a) occurs in the elapsed time after the engine stop. Specify the range for the in-cylinder fuel amount. Here, the in-cylinder fuel amount increases with time because the fuel pipe pressure remains even after the engine is stopped, and thus fuel leakage from the injector occurs.

  On the other hand, based on the relationship between the water temperature or the intake air temperature and the compression end temperature as shown in FIG. 4C, the water temperature or the intake air temperature is the compression end temperature at which self-ignition occurs in FIG. Specify a range. Finally, a map as shown in FIG. 3 is constructed on the basis of the elapsed time after the engine is stopped at which self-ignition occurs and the water temperature or intake air temperature at which self-ignition occurs.

  Returning to FIG. 2 again, after the process of step S102, the ECU 20 determines whether or not the elapsed time T since the previous stop of the engine 11 is Tth-α or more (step S103). Here, “α” is a margin appropriately determined according to the configuration of the engine 11 and the vehicle 1 or the like. In the present embodiment, as shown in FIG. 3, the predetermined time Tth is determined as the boundary line of the self-ignition region, so that self-ignition occurs even if some control is performed when the predetermined time Tth is reached. there's a possibility that. Therefore, the self-ignition is surely avoided by reducing the predetermined time Tth by α and performing the process of step S104 described later.

  Note that “Tth−α” according to the present embodiment is an example of the “second predetermined value” according to the present invention. This is because, as described above, the amount of in-cylinder fuel (that is, the amount of fuel leakage from the injector 115) is taken into account when calculating the predetermined time Tth.

  When it is determined that the elapsed time T is less than Tth−α (step S103: No), the ECU 20 once ends the process. On the other hand, when it is determined that the elapsed time T is equal to or greater than Tth−α (step S103: Yes), the ECU 20 controls the engine 11 so that the engine 11 operates only for a short time (step S104).

  Specifically, for example, as shown in FIG. 5, since the amount of fuel existing in the cylinder of the engine 11 is reduced by operating the engine 11 at the time Tth, self-ignition is performed when the engine is started next time. Can be suppressed. FIG. 5 is an example of the relationship between time and vehicle speed.

Second Embodiment
A second embodiment of the restart control device of the present invention will be described with reference to FIGS. The second embodiment is the same as the configuration of the first embodiment except that the engine restart control process executed by the ECU 20 is partially different. Specifically, the second embodiment is different from the first embodiment in that the amount of fuel leakage from the injector is corrected by the fuel pressure. Therefore, in the second embodiment, the description overlapping with that in the first embodiment is omitted, and the common portions in the drawings are denoted by the same reference numerals, and only FIGS. 6 to 8 are basically different only. The description will be given with reference.

  In FIG. 6, the ECU 20 calculates a fuel pressure correction coefficient kpr from a map as shown in FIG. 7, for example, based on the fuel pressure detected by the pressure sensor 22 after the process of step S102 shown in FIG. 2 (step S201). ). FIG. 7 is an example of a map that defines the relationship between the fuel pressure and the fuel pressure correction coefficient kpr.

  The map shown in FIG. 7 may be constructed based on the relationship between the fuel pressure and the amount of fuel leak from the direct injection injector per unit time, for example, as shown in FIG. Here, the reason why the fuel leak amount per unit time has a peak is as follows. That is, when the fuel pressure is relatively low, the amount of fuel leak per unit time increases according to the fuel pressure. However, as shown in FIG. 8B, when the fuel pressure becomes high, the injector blanker is pressed against the wall surface of the injector, and the gap through which the fuel flows becomes small. For this reason, when the fuel pressure increases to some extent, the amount of fuel leak per unit time decreases.

  Returning to FIG. 6 again, after step S201, the ECU 20 determines whether or not an elapsed time T since the previous stop of the engine 11 is equal to or greater than Tth * kpr-α (step S202).

  When it is determined that the elapsed time T is equal to or greater than Tth * kpr−α (step S202: Yes), the ECU 20 executes the process of step S104 described above. On the other hand, when it is determined that the elapsed time T is less than Tth * kpr−α (step S202: No), the ECU 20 once ends the process.

  Particularly in the present embodiment, the amount of fuel leak from the injector is corrected by the fuel pressure, so that self-ignition when the engine 11 is started can be reliably avoided.

<Third Embodiment>
A third embodiment according to the restart control device of the present invention will be described with reference to FIGS. 9 and 10. The third embodiment is the same as the configuration of the second embodiment except that the engine restart control process executed by the ECU 20 is partially different. Specifically, the third embodiment is different from the second embodiment in that the amount of fuel leakage from the injector is further corrected by the cumulative number of injections of the injector. Therefore, the description of the third embodiment that is the same as that of the second embodiment is omitted, and common portions in the drawings are denoted by the same reference numerals, and only the points that are basically different are shown in FIGS. 9 and 10. The description will be given with reference.

  In FIG. 9, the ECU 20 calculates a correction coefficient kinjn from a map as shown in FIG. 10, for example, based on the cumulative number of injections of the injector 115 after the process of step S201 shown in FIG. 6 (step S301). FIG. 10 is an example of a map that defines the relationship between the injector cumulative number of injections and the correction coefficient kinjn with the number of injections. It has been found by the inventor's research that when the cumulative number of injections of the injector 115 increases, the amount of fuel leakage decreases due to the running-in effect.

  Next, the ECU 20 determines whether or not the elapsed time T since the previous stop of the engine 11 is equal to or greater than Tth * kpr * kinjn-α (step S302). When it is determined that the elapsed time T is equal to or greater than Tth * kpr * kinjn−α (step S302: Yes), the ECU 20 executes the process of step S104 described above. On the other hand, when it is determined that the elapsed time T is less than Tth * kpr * kinjn−α (step S302: No), the ECU 20 once ends the process.

  Particularly in the present embodiment, the amount of fuel leakage from the injector is corrected by the cumulative number of injections of the injector, so that it is possible to reliably avoid self-ignition when the engine 11 is started, and to prevent the engine 11 from self-ignition. The number of times of starting can be reduced.

<Fourth embodiment>
A fourth embodiment according to the restart control device of the present invention will be described with reference to FIG. The fourth embodiment is the same as the configuration of the first embodiment except that the engine restart control process executed by the ECU 20 is partially different. Accordingly, the description of the fourth embodiment that is the same as that of the first embodiment will be omitted, and common parts in the drawings will be denoted by the same reference numerals, and only the points that are basically different will be described with reference to FIG. explain.

  In FIG. 11, first, the ECU 20 determines whether or not the intake air temperature and / or the water temperature detected by the temperature sensor 21 is equal to or higher than a predetermined value (step S401). When it is determined that the detected intake air temperature and / or water temperature is lower than the predetermined value (step S401: No), the ECU 20 once ends the process.

  When it is determined that the detected intake air temperature and / or water temperature is equal to or higher than a predetermined value (step S401: Yes), the ECU 20 calculates a predetermined time Tth determined by the water temperature or the intake air temperature (step S402). Next, the ECU 20 determines whether or not an elapsed time T since the previous stop of the engine 11 is Tth−α or more (step S403).

  When it is determined that the elapsed time T is less than Tth−α (step S403: No), the ECU 20 once ends the process. On the other hand, when it is determined that the elapsed time T is equal to or greater than Tth−α (step S403: Yes), the ECU 20 controls the injector 115 so as not to supply fuel, and controls the motor 11 to crank the engine 11. The generator MG1 is controlled (step S404).

  Since the fuel present in the cylinder is scavenged due to the cranking of the engine 11, the occurrence of self-ignition can be suppressed when the engine 11 is started next time.

<Fifth Embodiment>
A fifth embodiment of the restart control device of the present invention will be described with reference to FIG. The fifth embodiment is the same as the configuration of the fourth embodiment except that the engine restart control process executed by the ECU 20 is partially different. Accordingly, the description of the fifth embodiment that is the same as that of the fourth embodiment is omitted, and common portions in the drawing are denoted by the same reference numerals, and only the points that are fundamentally different refer to FIG. explain.

  In FIG. 12, when it is determined in the process of step S403 shown in FIG. 11 that the elapsed time T is equal to or greater than Tth−α (step S403: Yes), the ECU 20 stops the exhaust valve 114 in the closed state. For example, a variable valve timing mechanism (not shown) or the like is controlled (step S501). Next, the ECU 20 executes the process of step S404 described above.

  Particularly in the present embodiment, when the engine 11 is cranked, the exhaust valve 114 is closed, so that the fuel in the cylinder can be prevented from being scavenged to the exhaust passage 112 side. As a result, it is possible to suppress the deterioration of emission, which is very advantageous in practice.

<Sixth Embodiment>
A sixth embodiment according to the restart control device of the present invention will be described with reference to FIGS. 13 and 14. The sixth embodiment is the same as the configuration of the fourth embodiment except that the engine restart control process executed by the ECU 20 is partially different. Accordingly, the description of the sixth embodiment that is the same as that of the fourth embodiment is omitted, and common portions in the drawing are denoted by the same reference numerals, and only FIGS. 13 and 14 are basically different. The description will be given with reference.

  In FIG. 13, when it is determined in the process of step S403 shown in FIG. 11 that the elapsed time T is equal to or greater than Tth−α (step S403: Yes), the ECU 20 determines that the integrated value Qsouki of the scavenged fuel amount is Then, as an example of the “third predetermined value” according to the present invention, it is determined whether or not it is equal to or larger than a predetermined value (step S601).

  Here, the predetermined value is, for example, a ratio between the air amount Vs in the surge tank (not shown) and the integrated value Qsuki (that is, Vs / Qsuki) is an excess of the air-fuel ratio when the fuel is supplied from the injector 115. It is set as a value that is smaller by a predetermined value than a value that is rich (that is, a state in which the air-fuel ratio is richer than the air-fuel ratio in the combustible range of about 9 to 18).

  When it is determined that the integrated value Qsuki is greater than or equal to the predetermined value (step S601: Yes), the ECU 20 controls the injector 115 so as to supply fuel so that the engine 11 operates only for a short time. Is controlled (step S602), and the integrated value Qsuki is cleared (step S603).

  Specifically, for example, as shown by a solid line a in FIG. 14, when the integrated value Qsukii increases with time, the engine 11 is operated at a timing at which the solid line a intersects with a dotted line (that is, a predetermined value). The amount of fuel present in the fuel is reduced. After the engine 11 is stopped, the integrated value Qsuki increases with time as indicated by the solid line b in FIG. FIG. 14 is an example of the relationship between the number of scavenging times (that is, time) and the integrated value of the scavenged fuel amount.

  Returning to FIG. 13 again, when it is determined that the integrated value Qsuki is less than the predetermined value (step S601: No), the ECU 20 controls, for example, a variable valve timing mechanism or the like so that the exhaust valve 114 stops in the closed state. (Step S604). Subsequently, the ECU 20 controls the injector 115 so as not to supply fuel, controls the motor / generator MG1 to crank the engine 11 (step S605), and integrates the scavenged fuel amount (step S605). S606).

  In the present embodiment, in particular, since the engine 11 is operated when it is determined that the integrated value Qsuki is equal to or greater than a predetermined value, misfire can be suppressed when the engine 11 is started next time.

<Seventh embodiment>
A seventh embodiment according to the restart control device of the present invention will be described with reference to FIGS. 15 and 16. The seventh embodiment is the same as the first embodiment except that the engine restart control process executed by the ECU 20 is partially different. Accordingly, the description of the seventh embodiment that is the same as that of the first embodiment is omitted, and common portions in the drawings are denoted by the same reference numerals, and only the points that are basically different are shown in FIGS. 15 and 16. The description will be given with reference.

  In FIG. 15, first, the ECU 20 determines whether or not the intake air temperature and / or the water temperature detected by the temperature sensor 21 is equal to or higher than a predetermined value (step S701). When it is determined that the detected intake air temperature and / or water temperature is lower than the predetermined value (step S701: No), the ECU 20 once ends the process.

  When it is determined that the detected intake air temperature and / or water temperature is equal to or higher than the predetermined value (step S702: Yes), the ECU 20 determines whether there is a request to start the engine 11 (step S702). When it is determined that there is no request for starting the engine 11 (step S702: No), the ECU 20 calculates a predetermined time Tth determined by the water temperature or the intake air temperature (step S703). Next, the ECU 20 determines whether or not an elapsed time T since the previous stop of the engine 11 is equal to or greater than Tth−α (step S704).

  When it is determined that the elapsed time T is less than Tth−α (step S704: No), the ECU 20 once ends the process. On the other hand, when it is determined that the elapsed time T is equal to or greater than Tth−α (step S704: Yes), the ECU 20 controls, for example, a variable valve timing mechanism or the like so that the exhaust valve 114 stops in a closed state (step S704). S705).

  Subsequently, the ECU 20 controls the injector 115 so as not to supply fuel, controls the motor / generator MG1 to crank the engine 11 (step S706), and integrates the scavenged fuel amount (step S706). S707).

  In the process of step S702, when it is determined that there is a request for starting the engine 11 (step S702: Yes), the ECU 20 considers the scavenging fuel and is the amount of fuel supplied from the injector 115 when the engine 11 is started. The starting injection amount is calculated (step S708). As a result, when the engine 11 is started, the amount of fuel in the intake air can be suppressed from exceeding the combustible range and becoming excessive.

  Specifically, for example, as shown in FIG. 16, the ECU 20 determines the amount of fuel contained in the intake air from the base injection amount Qbase that is the original starting injection amount (intake amount × integrated value Qsouki / surge tank capacity Vs). The value obtained by subtracting only is calculated as the starting injection amount. FIG. 16 is an example of the relationship between the number of scavenging times (that is, time) and the starting injection amount.

  Returning to FIG. 15 again, after the processing of step S708, the ECU 20 controls the engine 11 so that the engine 11 operates while controlling the injector 115 so as to supply the fuel by the calculated injection amount at the start. At the same time (step S709), the integrated value Qsuki is cleared (step S710).

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit or idea of the invention that can be read from the claims and the entire specification, and restart control with such a change. The apparatus is also included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 11 ... Engine, 20 ... ECU, 21 ... Temperature sensor, 22 ... Pressure sensor, 100 ... Restart control device, 111 ... Intake passage, 112 ... Exhaust passage, 113 ... Intake valve, 114 ... Exhaust valve, 115 ... Injector, MG1, MG2 ... Motor / Generator

Claims (7)

Mounted in a vehicle with an engine,
Temperature detecting means for detecting the temperature of the engine;
Fuel supply means capable of supplying fuel to the engine;
When the engine is stopped, the engine is started so that the detected temperature is higher than a first predetermined value and the amount of fuel leakage from the fuel supply means is larger than a second predetermined value. A restart control device comprising: control means for controlling   The restart control device according to claim 1, wherein the control unit obtains the fuel leak amount based on a fuel pressure of the fuel.   The control means controls the engine so that a crankshaft of the engine rotates while controlling the fuel supply means so that the fuel is not supplied when the engine is started. Item 3. The restart control device according to Item 1 or 2.   The control means controls the fuel supply means so that the fuel is not supplied when the engine is started, and controls the engine so that the crankshaft rotates while the exhaust valve of the engine is closed. The restart control device according to claim 3, wherein the restart control device controls the restart control device.   The control means controls the engine to operate while controlling the fuel supply means to supply the fuel on condition that the amount of fuel in the intake air is larger than a third predetermined value. The restart control device according to claim 4.   5. The restart control device according to claim 4, wherein the control unit calculates a fuel amount to be supplied by the fuel supply unit based on a fuel amount in intake air.   The restart control device according to any one of claims 1 to 6, wherein the vehicle is a hybrid vehicle.

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