JP5077045B2 - Control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress worsening of fuel costs while improving driveability by suppressing a torque change in the case of stopping an internal combustion engine in a high load operating state. <P>SOLUTION: The controller (1) of the internal combustion engine in a vehicle is provided with: an internal combustion engine (11) and a motor (22) which can output motive power to a driving shaft (252) independently of each other; a battery (32) for supplying power to the motor; and a fuel supply means (15) for supplying fuel (16a) to the internal combustion engine. The controller of the internal combustion engine is provided with: a residual charge amount detection means (42) for detecting the residual charge amount of the battery; and a control means (31) for, when the motive power is output from each of the internal combustion engine and the motor to a driving shaft, determining the supply amount of fuel to set engine torque of the internal combustion engine to prescribed engine torque on condition that the detected residual charge amount is larger than a charge threshold and for controlling the fuel supply means to approach the determined supply quantity, when stopping of the internal combustion engine is instructed. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a control device for an internal combustion engine in a vehicle such as a hybrid vehicle including an internal combustion engine and a motor / generator, and particularly to a case where the internal combustion engine is stopped when the vehicle is driven by the internal combustion engine and the motor / generator. The present invention relates to the technical field of control of internal combustion engines.

  In this type of control device, it is possible to improve drivability by suppressing a change in torque when the internal combustion engine in a high-load operation state is stopped. For example, in Patent Document 1, when braking power is required for the drive shaft, the internal combustion engine is once controlled to operate at zero torque, and then the ignition advance is gradually controlled to a predetermined amount to retard the engine. A technique for cutting the supplied fuel is disclosed.

JP 2004-169576 A

  However, the technique described in Patent Document 1 has a technical problem that fuel consumption may deteriorate because the internal combustion engine is driven from when the internal combustion engine is set to zero torque until fuel is cut. .

  The present invention has been made in view of the above problems, for example, and suppresses a change in torque when stopping an internal combustion engine in a high-load operation state, thereby improving drivability and suppressing deterioration of fuel consumption. It is an object of the present invention to provide a control device for an internal combustion engine that can be used.

  In order to solve the above-described problems, an internal combustion engine control apparatus according to the present invention includes an internal combustion engine and a motor that can output power independently to a drive shaft, a battery that supplies electric power to the motor, and the internal combustion engine. A control device for the internal combustion engine in a vehicle comprising fuel supply means capable of supplying fuel to the battery, the remaining charge detection means for detecting the remaining charge of the battery, and the drive from each of the internal combustion engine and the motor If there is an instruction to stop the internal combustion engine when the power is being output to the shaft, the engine torque of the internal combustion engine is a predetermined engine torque on the condition that the detected remaining charge is greater than a charging threshold. And a control means for controlling the fuel supply means so as to approach the determined supply amount.

  According to the control apparatus for an internal combustion engine of the present invention, a vehicle on which the control apparatus is mounted includes an internal combustion engine and a motor that can output power independently of each other to a drive shaft, a battery that supplies electric power to the motor, and And a fuel supply means capable of supplying fuel to the internal combustion engine. Here, the “motor” according to the present invention is a motor for driving a vehicle, but may be a motor realized in, for example, a motor generator (electric motor). That is, as long as it can function as a motor, it may typically mean a motor / generator used in a hybrid vehicle.

  The fuel supply means such as a fuel injection valve may supply fuel into the internal combustion engine (that is, into the cylinder) (that is, a direct injection type internal combustion engine) or connected to the internal combustion engine, for example. Fuel may be supplied into the intake passage.

  The remaining charge detection means detects the remaining charge of the battery. For example, the control means configured to include a memory, a processor, and the like may detect the remaining charge remaining when an instruction to stop the internal combustion engine is issued when power is output from the internal combustion engine and the motor to the drive shaft. On the condition that the engine torque of the internal combustion engine becomes a predetermined engine torque, the fuel supply means is controlled so as to approach the determined supply amount.

  Here, “power is output from each of the internal combustion engine and the motor to the drive shaft” means that the vehicle is driven by the internal combustion engine and the motor. In addition, “when there is an instruction to stop the internal combustion engine” means, for example, that the amount of depression of the accelerator pedal is small (that is, the accelerator opening is small) or the brake pedal is depressed so that the driving state of the vehicle Means that the internal combustion engine does not need to be operated, and for example, an internal combustion engine stop instruction signal is transmitted from an ECU (Electronic Control Unit).

  The “predetermined engine torque” according to the present invention is a torque shock caused by stopping the internal combustion engine (typically, a torque output by the motor by a torque output immediately before the internal combustion engine is stopped). This means torque that does not affect drivability. Alternatively, a torque shock (typically, a shock due to a change in torque output by the motor by the torque difference between the internal combustion engine before and after the torque change) due to a change in the current engine torque is a driver. This means torque that does not affect the performance.

  “To approach the determined supply amount” typically means that the torque change amount of the internal combustion engine in a minute time when the supply amount is decreased from the current supply amount to the determined supply amount is determined by the driver. This means that the current supply amount gradually approaches the determined supply amount so that the torque change amount does not affect the performance.

  The “remaining charge threshold value” according to the present invention determines whether or not to control the fuel supply means so as to approach the determined supply amount by determining the supply amount of fuel that becomes the predetermined engine torque. It is a value that is set in advance as a fixed value or as a variable value according to some parameter. Such a remaining charge threshold value is, for example, 80% of the total charge amount. For example, the relationship between the remaining charge amount and the period during which the motor can be operated is empirically or experimentally or simulated. What is necessary is just to set as a charge remaining amount which can operate a motor for a predetermined period based on the calculated | required relationship.

  The “predetermined period” typically means a period in which the period from when the internal combustion engine is stopped to when the internal combustion engine is started next does not give the driver an uncomfortable feeling or discomfort. Specifically, for example, it means a period in which vibration or the like due to repeated stop and start of the internal combustion engine does not cause the driver or the like to feel uncomfortable or uncomfortable.

  According to the research of the present inventor, when the vehicle is driven by an internal combustion engine and a motor, and the internal combustion engine outputs a large torque (that is, high load operation), the internal combustion engine is immediately If the engine is stopped, the torque output from the motor increases rapidly, and drivability may deteriorate. In addition, since the air-fuel ratio is not stable during high load operation of the internal combustion engine, for example, the fuel and oxygen concentration in the catalyst provided in the exhaust passage such as a three-way catalyst cannot be optimized, and the catalyst There is a risk of deterioration.

  On the other hand, a technique has been proposed in which the internal combustion engine is stopped after the internal combustion engine is idled for a certain period of time before the internal combustion engine is stopped. However, since torque is output from the internal combustion engine even in the idle state, drivability may be deteriorated when the internal combustion engine is stopped. Further, it has been found that there is a possibility that the fuel consumption may deteriorate by continuing the idle state for a certain period.

  However, in the present invention, when the stop means of the internal combustion engine is instructed when power is output from the internal combustion engine and the motor to the drive shaft by the control means, the detected remaining charge amount is greater than the charge threshold value. The fuel supply amount at which the engine torque of the internal combustion engine becomes a predetermined engine torque is determined on the condition, and the fuel supply means is controlled so as to approach the determined supply amount. As a result, the internal combustion engine can be stopped relatively early, and a torque shock caused by stopping the internal combustion engine can be suppressed.

  As a result of the above, according to the control device for an internal combustion engine of the present invention, it is possible to suppress a change in torque when stopping the internal combustion engine in a high-load operation state, thereby improving drivability and suppressing deterioration of fuel consumption. Can do.

  In one aspect of the control apparatus for an internal combustion engine of the present invention, the control means includes data for defining a relationship between torque detection means for detecting the engine torque, and the supply amount of the fuel that becomes the engine torque and the predetermined engine torque. The fuel supply amount to be the predetermined engine torque is determined from the data according to the detected engine torque.

  According to this aspect, it is possible to determine the amount of fuel to be supplied with a predetermined engine torque relatively easily, which is very advantageous in practice.

  For example, torque detection means such as a torque sensor detects the engine torque of the internal combustion engine. In a vehicle in which the internal combustion engine can output power to the drive shaft via a damper, the engine torque may be detected or estimated based on, for example, a torsion torque of the damper.

  For example, the storage means such as a non-volatile memory stores data that defines the relationship between the engine torque and the fuel supply amount that becomes the predetermined engine torque. The data is empirically or experimentally or by simulation, for example, the torque difference between the engine torque at the time when the stop instruction of the internal combustion engine is instructed and the predetermined engine torque, and the torque difference does not affect drivability. What is necessary is just to obtain | require the relationship with the supply amount which can operate an internal combustion engine without misfiring at least the period which can be made into zero, and to comprise based on this calculated | required relationship.

  The control means determines the supply amount of fuel that becomes the predetermined engine torque from the data according to the detected engine torque.

  Alternatively, in another aspect of the control device for an internal combustion engine of the present invention, the control means includes torque detection means for detecting the engine torque, and the predetermined engine torque is obtained based on the detected engine torque. Determine the fuel supply.

  According to this aspect, the control means determines the supply amount of fuel that becomes the predetermined engine torque, based on the detected engine torque. The torque detection means detects the engine torque periodically, irregularly or continuously, and the control means corrects the supply amount determined sequentially based on the detected engine torque. Also good.

  In another aspect of the control device for an internal combustion engine according to the present invention, the control means includes a supply amount determining means for determining a supply amount of the fuel that becomes the predetermined engine torque.

  According to this aspect, since the control means includes the supply amount determination means configured to include, for example, a memory, a processor, etc., it is relatively easy to determine the supply amount of fuel that becomes the predetermined engine torque. This is very advantageous in practice.

  In another aspect of the control device for an internal combustion engine of the present invention, the internal combustion engine can output the power to the drive shaft via a damper.

  According to this aspect, it is possible to reduce the torsional vibration of the drive system, and as a result, it is possible to reduce the booming noise and vibration in the vehicle interior. The “damper” according to the present invention is typically a transaxle damper.

  In another aspect of the control device for an internal combustion engine of the present invention, an exhaust passage connected to the internal combustion engine, a catalyst provided in the exhaust passage, temperature detecting means for detecting the temperature of the catalyst, and the internal combustion engine Ignition timing changing means capable of changing the ignition timing of the internal combustion engine when the power is being output from the internal combustion engine and the motor to the drive shaft. If the detected amount of charge remaining is greater than the charge threshold value and the detected temperature is lower than the temperature threshold value, the fuel supply means is adjusted so as to approach the determined supply amount. While controlling, the ignition timing changing means is controlled so that the ignition timing is retarded.

  According to this aspect, the exhaust passage connected to the internal combustion engine is provided with a catalyst such as a three-way catalyst. For example, temperature detection means that is a temperature sensor detects the temperature of the catalyst. For example, the ignition timing changing means configured to include a memory, a processor, and the like can change the ignition timing of the internal combustion engine.

  When power is being output from the internal combustion engine and the motor to the drive shaft, and when there is an instruction to stop the internal combustion engine, the control means detects that the remaining charge level is greater than the charge threshold and is detected. On the condition that the temperature is lower than the temperature threshold, the fuel supply means is controlled so as to approach the determined supply amount, and the ignition timing changing means is controlled so that the ignition timing is retarded.

  Thereby, a catalyst can be warmed up and deterioration of a catalyst can be suppressed. The “temperature threshold” according to the present invention is a value that determines whether or not to control the ignition timing changing means so that the ignition timing is retarded, and is previously set as a fixed value or variable according to some parameter. It is a value set as a value. Such a temperature threshold is obtained by empirically or experimentally or by simulation, for example, by obtaining the relationship between the temperature of the catalyst and the purification capability of the catalyst, and the purification capability of the catalyst is significantly reduced based on the obtained relationship. What is necessary is just to set as temperature to carry out, or a temperature higher by a predetermined value than this temperature.

  The operation and other advantages of the present invention will become apparent from the best mode for carrying out the invention described below.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment according to a control device for an internal combustion engine of the present invention will be described with reference to the drawings.

<First Embodiment>
A first embodiment of the control apparatus for an internal combustion engine according to the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing the configuration of the control device according to this embodiment. In addition, the dashed-dotted line in a figure has shown the flow of electric power.

  In FIG. 1, a vehicle on which the control device 1 according to this embodiment is mounted includes an engine 11, motor generators 21 and 22, a power distribution mechanism 23, a damper 24, and a battery 32.

  An intake passage 12 and an exhaust passage 13 are connected to the engine 11. The intake passage 12 is provided with a fuel injection valve 15 that can supply fuel 16a such as gasoline stored in a fuel tank 16 via a delivery pipe 15a. A catalyst 14 such as a three-way catalyst is provided in the exhaust passage 13.

  The “engine 11”, “fuel injection valve 15” and “motor / generators 21 and 22” according to the present embodiment are respectively the “internal combustion engine”, “fuel supply means” and “motor” according to the present invention. It is an example.

  The motor / generator 21 includes a rotor 211 and a stator 212, and the motor / generator 22 includes a rotor 221 and a stator 222.

  The power distribution mechanism 23 includes a planetary carrier 234, a sun gear 235, a planetary gear 236, a ring gear 237, and a power take-out gear 238. The carrier shaft 231 connected to the planetary carrier 234 is connected to the crankshaft 111 of the engine 11 via the damper 24. A sun gear shaft 232 connected to the sun gear 235 is connected to the rotor 211. A ring gear shaft 233 connected to the ring gear 237 is connected to the rotor 221. The power take-out gear 238 can transmit power to a power transmission gear 251 connected to one end of the drive shaft 252 via a chain belt (not shown).

  The control device 1 includes an ECU 31, a catalyst temperature sensor 41, a remaining charge sensor 42, and a torque sensor 43. Here, the “catalyst temperature sensor 41”, “remaining charge sensor 42”, and “torque sensor 43” according to the present embodiment are respectively referred to as “temperature detection means”, “remaining charge detection means”, and It is an example of “torque detection means”. The “ECU 31” according to the present embodiment is an example of the “control unit”, “storage unit”, “supply amount determining unit”, and “ignition timing changing unit” according to the present invention. In the present embodiment, a part of the ECU 31 for various electronic controls is used as a part of the control device 1.

  Next, while the vehicle equipped with the control device 1 configured as described above is traveling (typically, when the vehicle is driven by the engine 11 and the motor / generator 22), the engine stop executed by the ECU 31 is performed. The processing will be described with reference to the flowchart of FIG.

  In FIG. 2, first, the ECU 31 detects the operation state of the vehicle by detecting the number of revolutions of the engine 11, the amount of depression of an accelerator pedal (not shown), the amount of depression of a brake pedal (not shown), and the like. Obtain (step S101). Subsequently, the ECU 31 turns off the engine operation request flag (that is, issues an engine stop request) on the condition that the acquired operation state is a state where it is not necessary to operate the engine 11 (step S102). .

  Next, the ECU 31 determines whether or not the engine 11 is operating (step S103). When it is determined that the engine 11 is not operating (step S103: No), the process is temporarily terminated. On the other hand, when it is determined that the engine 11 is operating (step S103: Yes), the ECU 31 determines whether or not there is an idle request (that is, a request to place the engine 11 in an idle state) (step S104). .

  When it is determined that there is an idle request (step S104: Yes), the ECU 31 controls the engine 11 so as to continue the operation (step S111), and once ends the process. On the other hand, when it is determined that there is no idle request (step S104: No), the ECU 31 acquires the remaining charge of the battery 32 via the remaining charge sensor 42 (step S105).

  Next, the ECU 31 determines whether or not the acquired remaining charge is larger than a remaining charge threshold that is, for example, 80% of the total charge (step S106). When it is determined that it is smaller than the remaining charge threshold (step S106: No), the ECU 31 controls the engine 11 so as to continue the operation (step S111) and once ends the process.

  On the other hand, when it is determined that it is larger than the remaining charge threshold (step S106: Yes), the ECU 31 acquires the torsion torque of the damper 24 via the torque sensor 43, and based on the acquired torsion torque, the ECU 11 Get torque. Subsequently, the ECU 31 stores, for example, a data table 501 stored in a memory (not shown) according to the acquired torque, for example, from the data table 501 shown in FIG. The supply amount of the fuel 16a capable of operating is determined (step S107).

  FIG. 3 is a conceptual diagram of a data table that defines the relationship between the torque difference between the current torque of the engine 11 and the minimum torque stored in the ECU 31 according to the present embodiment, and the amount of fuel supplied at the minimum torque. It is. In the process of step S106, when the acquired remaining charge amount and the remaining charge threshold value are “equal”, they may be included in either case.

  Next, the ECU 31 controls the fuel injection valve 15 so that the amount of fuel 16a supplied from the fuel injection valve 15 approaches the determined supply amount (step S108). The ECU 31 gradually changes the supply amount so that the change amount of the torque of the engine 11 resulting from the change of the supply amount of the fuel 16a becomes a change amount that does not affect the drivability. The fuel injection valve 15 is controlled.

  In parallel with the process of step S108, the ECU 31 acquires the torsional torque of the damper 24 via the torque sensor 43, and acquires the torque of the engine 11 based on the acquired torsional torque. Subsequently, the ECU 31 determines whether or not the acquired torque has reached the minimum torque (step S109).

  When it is determined that the minimum torque has not been reached (step S109: No), the ECU 31 continues the process of step S108. On the other hand, when it is determined that the minimum torque has been reached (step S109: Yes), the ECU 31 stops the engine 11 (step S110), and once ends the process.

  Next, the operation state of the vehicle during the engine stop process described above will be described with reference to FIG. FIG. 4 is a conceptual diagram showing changes over time in the engine speed and torque and the amount of charge per unit time of the battery during the engine stop process according to the present embodiment. In addition, the dotted line in a figure has shown the time change of the rotation speed and torque of the engine in the engine stop process which concerns on the comparative example of this embodiment, and the charge amount per unit time of a battery.

  At time t0 in FIG. 4, for example, when the operator reduces the amount of depression of the accelerator pedal, the rotational speed and torque of the engine 11 decrease, and the operation state of the vehicle changes from the time t0 to the time t1. 11 shifts to a state where the operation is not necessary.

  The ECU 31 controls the fuel supply valve 15 from time t1 so that the supply amount of the fuel 16a becomes the supply amount determined in the process of step S107. As a result, the torque of the engine 11 gradually approaches the minimum torque while maintaining the rotation speed equivalent to that in the idle state. At time t2, the ECU 31 determines that the minimum torque has been reached, and the engine 11 is stopped.

  If the engine 11 is stopped after the engine 11 is idled for a certain period (for example, from time t1 to time t3 in FIG. 4) without changing the supply amount of the fuel 16a, Although the rotational speed is the same, torque corresponding to the idle state is output. Then, when the engine 11 is stopped at time t3, a torque shock caused by a change in the torque of the motor / generator 22 by an amount corresponding to the torque corresponding to the idle state may occur, and drivability may be deteriorated.

  By the way, due to the rotation of the engine 11, the rotor 211 of the motor / generator 21 is rotated and the battery 11 is charged. For this reason, there exists a possibility of becoming an overcharge state depending on the charge remaining amount of the battery 11. However, in this embodiment, when the torque of the engine 11 decreases, the amount of charge per unit time decreases, and the battery 11 can be prevented from being overcharged.

  In the present embodiment, the supply amount of the fuel 16a is determined from the data table 501, but instead of the data table 501, for example, the torque difference between the current engine torque and the minimum torque and the minimum torque are obtained. A map that defines the relationship with the fuel supply amount may be stored in a memory, and the fuel 16a supply amount may be determined from the stored map.

Second Embodiment
A second embodiment of the control device for an internal combustion engine of the present invention will be described with reference to FIG. The second embodiment is the same as the configuration of the first embodiment except that the engine stop process executed by the ECU is partially different. Therefore, in the second embodiment, the description overlapping with that of the first embodiment is omitted, and common portions on the drawing are denoted by the same reference numerals, and only fundamentally different points are described with reference to FIG. explain. FIG. 5 is a flowchart showing the engine stop process executed by the ECU according to this embodiment.

  In FIG. 5, after it is determined that the acquired remaining charge is larger than the remaining charge threshold (step S106: Yes), the ECU 31 acquires the temperature of the catalyst 14 via the catalyst temperature sensor 41 (step S201). . Subsequently, the ECU 31 determines whether or not the acquired temperature is higher than a temperature threshold (step S202).

  When it is determined that the temperature is higher than the temperature threshold value (step S202: Yes), the ECU 31 executes the processing after step S107 shown in FIG. On the other hand, when it is determined that the temperature is lower than the temperature threshold (that is, when the temperature of the catalyst 14 is relatively low and the purification capability may be deteriorated) (step S202: No), the ECU 31 receives a damper via the torque sensor 43. 24 torsional torques are acquired, and the torque of the engine 11 is acquired based on the acquired torsional torques.

  Subsequently, according to the acquired torque, the ECU 31 can operate the engine 11 with the minimum torque from the same data table as the data table 501 shown in FIG. 3 and can suppress the deterioration of the purification capacity. The supply amount of the fuel 16a is determined (step S203).

  When the acquired temperature and the temperature threshold are “equal”, they may be included in either case.

  In tandem with the process of step S203, the ECU 31 changes the ignition timing to the retard side within a range where the torque fluctuation amount of the engine 11 is allowed (step S204). Next, the ECU 31 controls the fuel injection valve 15 so that the amount of fuel 16a supplied from the fuel injection valve 15 approaches the determined supply amount (step S205).

  In parallel with the process of step S205, the ECU 31 acquires the torsional torque of the damper 24 via the torque sensor 43, and acquires the torque of the engine 11 based on the acquired torsional torque. Subsequently, the ECU 31 determines whether or not the acquired torque has reached the minimum torque (step S206).

  When it is determined that the minimum torque has not been reached (step S206: No), the ECU 31 continues the process of step S205. On the other hand, when it is determined that the minimum torque has been reached (step S206: Yes), the ECU 31 stops the engine 11 (step S110) and once ends the process.

<Third Embodiment>
A third embodiment of the control apparatus for an internal combustion engine of the present invention will be described with reference to FIG. The third embodiment is the same as the configuration of the first embodiment except that the engine stop process executed by the ECU is partially different. Therefore, the description of the third embodiment that is the same as that of the first embodiment is omitted, and common portions in the drawing are denoted by the same reference numerals, and only fundamentally different points are described with reference to FIG. explain. FIG. 6 is a flowchart showing the engine stop process executed by the ECU according to this embodiment.

  In FIG. 6, after it is determined that the acquired remaining charge amount is larger than the remaining charge threshold value (step S <b> 106: Yes), the ECU 31 acquires the torsion torque of the damper 24 via the torque sensor 43. The torque of the engine 11 is acquired based on the twisted torque.

  Subsequently, based on the acquired torque, the ECU 31 determines the supply amount of the fuel 16a so that the torque of the engine 11 after a minute time decreases within a range that does not affect drivability (step S301). . Next, the ECU 31 controls the fuel injection valve 15 so that the amount of the fuel 16a supplied from the fuel injection valve 15 approaches the determined supply amount (step S302).

  In parallel with the process of step S302, the ECU 31 acquires the torsion torque of the damper 24 via the torque sensor 43, and acquires the torque of the engine 11 based on the acquired torsion torque. Subsequently, the ECU 31 determines whether or not the acquired torque has reached the minimum torque (step S303).

  When it is determined that the minimum torque has not been reached (step S303: No), the ECU 31 determines whether or not the torque of the engine 11 has changed before and after controlling the fuel injection valve 15 in the process of step S302. (Step S304). When it is determined that the torque has not changed (step S304: No), the ECU 31 corrects the supply amount of the fuel 16a (step S307), and executes the processing after step S302.

  On the other hand, when it is determined that the torque has changed (step S304: Yes), the ECU 31 increases (typically +1) the value of a variation determination counter (not shown) included in the ECU 31 (step S305). ).

  Next, the ECU 31 determines whether or not the value of the variation determination counter is greater than or equal to a threshold value (step S306). This threshold value is a value that determines whether or not the engine 11 is to be stopped, and is a value that is set in advance as a fixed value or as a variable value according to some parameter. Such a threshold value is determined, for example, by the minimum torque difference (for example, a value slightly larger than the measurement error range) that the ECU 31 determines that the torque of the engine 11 has changed, empirically, experimentally, or by simulation. When the torque decreases, the value may be set so as to be lower than the torque output when the engine 11 is in the idle state.

  When it is determined that the value of the variation determination counter is equal to or greater than the threshold (step S306: Yes), the ECU 31 stops the engine 11 (step S110) and ends the process once. As described above, even when the torque of the engine 11 does not reach the minimum torque, when it is determined that the value of the variation determination counter is equal to or greater than the threshold value, the engine 11 is stopped, thereby FIG. By repeating the process shown, it is possible to suppress a deterioration in fuel consumption caused by an unnecessarily long engine stop process. In addition, if the value of the fluctuation determination counter is equal to or greater than the threshold value, it is smaller than at least the torque output in the idling state, so that torque shock caused by stopping the engine 11 can be suppressed.

  If it is determined in step S306 that the value of the fluctuation determination counter is smaller than the threshold value (step S306: No), the ECU 31 corrects the supply amount of the fuel 16a (step S307), and performs the processing after step S302. Run.

  In the process of step S303, when it is determined that the minimum torque has been reached (step S303: Yes), the ECU 31 stops the engine 11 (step S110) and once ends the process.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. An engine control device is also included in the technical scope of the present invention.

It is a block diagram which shows the structure of the control apparatus which concerns on 1st Embodiment. It is a flowchart which shows the engine stop process which ECU which concerns on 1st Embodiment performs. It is a conceptual diagram of the data table which defines the relationship between the torque difference between the present engine torque and the minimum torque stored in the ECU according to the first embodiment, and the supply amount of fuel that becomes the minimum torque. It is a conceptual diagram which shows the time change of the rotation speed and torque of an engine in the engine stop process which concerns on 1st Embodiment, and the charge amount per unit time of a battery. It is a flowchart which shows the engine stop process which ECU which concerns on 2nd Embodiment performs. It is a flowchart which shows the engine stop process which ECU which concerns on 3rd Embodiment performs.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Control apparatus, 11 ... Engine, 12 ... Intake passage, 13 ... Exhaust passage, 14 ... Catalyst, 15 ... Fuel supply valve, 16 ... Fuel tank, 21, 22 ... Motor generator, 23 ... Power distribution mechanism, 24 ... Damper, 31 ... ECU, 32 ... Battery, 41 ... Catalyst temperature sensor, 42 ... Remaining charge sensor, 43 ... Torque sensor

Claims (7)

Control of the internal combustion engine in a vehicle comprising an internal combustion engine and a motor capable of outputting power to the drive shaft independently of each other, a battery for supplying electric power to the motor, and fuel supply means capable of supplying fuel to the internal combustion engine A device,
Remaining charge detection means for detecting the remaining charge of the battery;
When the motive power is being output from each of the internal combustion engine and the motor to the drive shaft, if there is an instruction to stop the internal combustion engine, the detected remaining charge is greater than a charging threshold. And a control means for determining the supply amount of the fuel at which the engine torque of the internal combustion engine becomes a predetermined engine torque, and controlling the fuel supply means so as to approach the determined supply amount. Control device for internal combustion engine. The control means includes
Torque detecting means for detecting the engine torque;
Storage means for storing data defining a relationship between the engine torque and the supply amount of the fuel that becomes the predetermined engine torque;
2. The control device for an internal combustion engine according to claim 1, wherein an amount of the fuel that becomes the predetermined engine torque is determined from the data according to the detected engine torque. 3. The control means includes
Including torque detection means for detecting the engine torque,
2. The control device for an internal combustion engine according to claim 1, wherein a supply amount of the fuel that becomes the predetermined engine torque is determined based on the detected engine torque. 3.   4. The control device for an internal combustion engine according to claim 1, wherein the control unit includes a supply amount determination unit that determines a supply amount of the fuel that becomes the predetermined engine torque. 5.   5. The control device for an internal combustion engine according to claim 1, wherein the internal combustion engine is capable of outputting the power to the drive shaft via a damper. An exhaust passage connected to the internal combustion engine;
A catalyst provided in the exhaust passage;
Temperature detecting means for detecting the temperature of the catalyst;
Ignition timing changing means capable of changing the ignition timing of the internal combustion engine, and
When the power is being output from each of the internal combustion engine and the motor to the drive shaft, and when there is an instruction to stop the internal combustion engine, the control means determines that the detected remaining charge is the charge threshold value. The ignition is performed so that the ignition timing is retarded while controlling the fuel supply means so as to approach the determined supply amount on condition that the detected temperature is lower than a temperature threshold. The control device for an internal combustion engine according to any one of claims 1 to 5, wherein the timing changing means is controlled.   The control device for an internal combustion engine according to any one of claims 1 to 6, wherein the control means further stops the internal combustion engine immediately after the engine torque reaches the predetermined engine torque.

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