JP7282448B2 - Control device for internal combustion engine - Google Patents

Description

The present invention relates to a control device that controls the operation of an internal combustion engine mounted on a vehicle.

When the driver depresses the accelerator pedal strongly and tries to accelerate the vehicle suddenly, the engine torque output from the internal combustion engine, which is the power source, suddenly increases, giving shock to the vehicle body, or There is a concern that hiccups (a phenomenon in which the vehicle body rocks back and forth) may occur.

Therefore, conventionally, when the accelerator opening suddenly increases from 0 or less than a threshold value close to 0, correction control is performed to temporarily retard the ignition timing of the air-fuel mixture in the cylinder of the internal combustion engine, thereby increasing the engine torque. The rise is moderated to avoid shocks to the vehicle body or hiccups (see, for example, the following patent documents).

JP 2015-121189 A

In the existing system, correction control was performed to temporarily retard the ignition timing only when the driver strongly depressed the accelerator pedal.

However, in reality, it is possible that the driver lightly depresses the accelerator pedal to start the vehicle, runs the vehicle for a certain period of time, and then strongly depresses the accelerator pedal to accelerate the vehicle. In this case, since correction control for retarding the ignition timing is not performed, shocks and jerks may occur in the vehicle body.

SUMMARY OF THE INVENTION The present invention has been made for the first time by paying attention to the above problems, and an intended object thereof is to appropriately suppress the shock or jerking phenomenon to the vehicle body to further improve the drivability.

In order to solve the above-described problems, in the present invention, the accelerator pedal is stepped on from a state where the accelerator opening is 0 or a threshold value close to 0 or less, the accelerator opening exceeds 0 or a threshold value close to 0, and the engine load factor is increased. A non-low-load state close to idling has continued for a first predetermined time or less , and the amount of increase in the engine load factor per unit time has exceeded a predetermined value within the first predetermined time during which the state continues. Moreover, the engine load factor exceeds the first predetermined value and the cooling water temperature of the internal combustion engine is higher than the predetermined value as a necessary condition. Correction control is performed, and the state in which the accelerator opening exceeds a threshold value of 0 or close to 0 and the engine load factor is close to idling and not low load without performing the first correction control is the first condition. It continues for a second predetermined time longer than the predetermined time, and the engine load factor exceeds the second predetermined value, and the engine load factor continues to increase, as a necessary condition. A control device for an internal combustion engine is configured that performs second correction control for retarding the ignition timing of the air-fuel mixture that has been adjusted.

With such a configuration, even if the driver depresses the accelerator pedal lightly to start the vehicle, and after running the vehicle for a certain amount of time, the driver depresses the accelerator pedal strongly, the sudden increase in the engine torque is suppressed by the second correction control. It becomes possible to effectively suppress the shock to the vehicle body or the hiccups.

More specifically, the first correction control is performed on the condition that the engine load factor exceeds a first predetermined value, and the engine load factor exceeds a second predetermined value. is a necessary condition for performing the second correction control, and the second predetermined value is preferably set to a higher value than the first predetermined value. As a result, when the accelerator pedal is strongly depressed from the state where the accelerator opening is 0 or less than the threshold close to 0, the first correction control can be quickly performed to suppress the occurrence of shock or hiccups in the vehicle body. When the accelerator pedal is strongly depressed in a state in which the accelerator opening is already opened to some extent, the second correction control is timely executed to suppress the shock or jerking of the vehicle body.

ADVANTAGE OF THE INVENTION According to this invention, a shock to a vehicle body or a jerking phenomenon can be suppressed appropriately, and drivability can be improved further.

1 is a diagram showing a schematic configuration of an internal combustion engine and a control device according to an embodiment of the present invention; FIG. FIG. 4 is a flow diagram showing an example of the procedure of processing executed by the control device according to the embodiment according to the program; FIG. 4 is a flow diagram showing an example of the procedure of processing executed by the control device according to the embodiment according to the program; FIG. 4 is a flow diagram showing an example of the procedure of processing executed by the control device according to the embodiment according to the program; FIG. 4 is a timing chart for explaining the contents of control performed by the control device of the embodiment; FIG. 4 is a timing chart for explaining the contents of control performed by the control device of the embodiment;

One embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of a vehicle internal combustion engine according to this embodiment. The internal combustion engine in this embodiment is a spark-ignited four-stroke gasoline engine, and includes a plurality of cylinders 1 (one of which is shown in FIG. 1). An injector 11 for injecting fuel toward the intake port is provided upstream of the intake valve of each cylinder 1 and in the vicinity of the intake port connected to each cylinder 1 . A spark plug 12 is attached to the ceiling of the combustion chamber of each cylinder 1 . The spark plug 12 receives an induced voltage generated by an ignition coil and induces spark discharge between a center electrode and a ground electrode. The ignition coil is integrally built into the coil case together with the igniter, which is a semiconductor switching element.

An intake passage 3 for supplying intake air takes in air from the outside and guides it to the intake port of each cylinder 1 . An air cleaner 31, an electronic throttle valve 32, a surge tank 33, and an intake manifold 34 are arranged in this order on the intake passage 3 from upstream.

An exhaust passage 4 for discharging exhaust guides the exhaust generated by burning fuel in the cylinder 1 from the exhaust port of each cylinder 1 to the outside. An exhaust manifold 42 and a three-way catalyst 41 for purifying exhaust gas are arranged on the exhaust passage 4 .

The exhaust gas recirculation device 2 realizes so-called high-pressure loop EGR, and is an external EGR device that communicates the upstream side of the catalyst 41 in the exhaust passage 4 and the downstream side of the throttle valve 32 in the intake passage 3. A passage 21 , an EGR cooler 22 provided on the EGR passage 21 , and an EGR valve 23 that opens and closes the EGR passage 21 to control the flow rate of EGR gas flowing through the EGR passage 21 are elements. The inlet of the EGR passage 21 is connected to the exhaust manifold 42 in the exhaust passage 4 or a predetermined location downstream thereof. The outlet of the EGR passage 21 is connected to a predetermined location downstream of the throttle valve 32 in the intake passage 3, specifically to a surge tank 33. As shown in FIG.

An ECU (Electronic Control Unit) 0, which is a control device for an internal combustion engine according to the present embodiment, is a microcomputer system having a processor, memory, input interface, output interface, and the like. The ECU 0 may be formed by connecting a plurality of ECUs or controllers so as to be able to communicate with each other via electric communication lines such as CAN (Controller Area Network).

The input interface of the ECU 0 receives a vehicle speed signal a output from a vehicle speed sensor that detects the actual vehicle speed, and a crank angle sensor that detects the rotation angle of the crankshaft, which is the output shaft of the internal combustion engine, and the engine speed. A crank angle signal b, an accelerator opening signal c output from a sensor that detects the amount of depression of the accelerator pedal or the opening of the throttle valve 32 as the accelerator opening (that is, the required engine load factor), the intake passage 3 (especially , intake air temperature and pressure signal d output from a temperature and pressure sensor that detects the intake air temperature and pressure in the surge tank 33), a sensor that detects the amount of depression of the brake pedal, or brake hydraulic fluid discharged from the master cylinder A brake pedaling amount signal e output from a sensor that detects the master cylinder pressure, which is the pressure of the engine, a cooling water temperature signal f output from a water temperature sensor that detects a cooling water temperature that indicates the temperature of the internal combustion engine, an intake camshaft or an exhaust cam A cam angle signal g output from a cam angle sensor at a plurality of cam angles of the shaft; Acceleration) signal h and the like are input.

From the output interface, an ignition signal i to the igniter of the spark plug 12, a fuel injection signal j to the injector 11, an opening operation signal k to the throttle valve 32, and an opening operation signal l to the EGR valve 23 etc.

The processor of the ECU 0 interprets and executes a program stored in memory in advance, calculates operating parameters, and controls the operation of the internal combustion engine. The ECU 0 acquires various types of information a, b, c, d, e, f, g, and h necessary for controlling the operation of the internal combustion engine via an input interface, Operation parameters such as the required fuel injection amount, fuel injection timing (including the number of fuel injections for one combustion), fuel injection pressure, ignition timing, and required EGR gas amount (or EGR rate) are determined. The ECU 0 applies various control signals i, j, k, l corresponding to the operating parameters through the output interface.

Further, the ECU 0 executes an idle stop for stopping the idle rotation of the internal combustion engine when a predetermined idle stop condition is satisfied. The ECU 0 determines that the amount of depression of the brake pedal or the master cylinder pressure is equal to or higher than a predetermined value (the brake pedal is depressed), the cooling water temperature of the internal combustion engine is higher than a predetermined value, and the charging amount or terminal voltage of the vehicle-mounted battery is equal to or higher than a predetermined value. is high, the shift range is the driving range, the absolute value of the slope of the road surface on which the vehicle is located is less than a predetermined value, the magnitude of the negative pressure stored in the brake booster is greater than a predetermined value, and the previous idle When all the conditions are satisfied, such as having a history of accelerating to a certain vehicle speed (for example, 10 km/h) or more after the end of the stop and the current vehicle speed is below a certain vehicle speed (for example, 9 km/h), the idle state is established. It is judged that the stop condition is satisfied.

After the idling stop condition is satisfied, the internal combustion engine is restarted when a predetermined idling stop end condition is satisfied. The ECU 0 determines that the amount of depression of the brake pedal or the master cylinder pressure has become 0 or less than the minimum value close to 0 (the brake pedal is no longer depressed), or conversely, the amount of depression of the brake pedal or the master cylinder pressure has further increased ( The brake pedal is stepped on more strongly), the accelerator opening increases (the accelerator pedal is stepped on), the amount of negative pressure stored in the brake booster drops below a predetermined value, or the idle stop state is maintained for a predetermined period of time. It is determined that the idling stop end condition has been met when a period of time (for example, 3 minutes) has elapsed.

When starting the stopped internal combustion engine (including not only recovery from idling stop but also cold start), the ECU 0 inputs a control signal o to the electric motor (starter or ISG (Integrated Starter Generator), not shown). Then, while the crankshaft is rotationally driven by the electric motor, cranking is performed by performing fuel injection from the injector 11 and spark ignition by the spark plug 12 . Cranking ends when the internal combustion engine goes from the first explosion to the continuous explosion and the engine speed exceeds the complete explosion judgment value. The complete explosion determination value, which is the condition for ending cranking, can fluctuate depending on the temperature of the internal combustion engine and the like. Specifically, the lower the cooling water temperature of the internal combustion engine, the higher the complete explosion determination value is set.

Thus, the ECU 0 of this embodiment causes a shock to the vehicle body or causes a hiccups such as the vehicle body to swing back and forth when the driver of the vehicle depresses the accelerator pedal to accelerate the vehicle. In order to appropriately suppress this, the ignition timing of the air-fuel mixture in cylinder 1 of the internal combustion engine is adjusted to the operating range of the internal combustion engine [engine speed, accelerator opening (or engine load factor, intake pressure in surge tank 33 , the amount of intake air charged into cylinder 1 or the amount of fuel injection)], etc., is performed to retard the base timing, thereby slowing the rise of the engine torque.

Hereinafter, correction control executed by the ECU 0 will be described in detail. 2 to 4 show an example of the procedure of processing executed by the ECU 0 of this embodiment. FIG. 2 shows processing for two counter values I and II that are constantly counted by the ECU 0 . Both the counter I and the counter II reach a first predetermined value corresponding to the current accelerator opening exceeding a threshold value of 0 or close to 0 and the current engine load factor corresponding to idle operation or low load operation close to it. As long as the precondition of exceeding is satisfied (step S1), it is increased by a predetermined amount per unit time (steps S2 and S4). The current accelerator opening is the amount of depression of the accelerator pedal or the opening of the throttle valve 32, as described above. The current engine load factor can be estimated from the current engine speed, the intake air pressure in the surge tank 33, the accelerator opening, and the like. The memory of the ECU 0 stores in advance map data or function formulas that define the relationship between the engine speed, intake pressure, accelerator opening, etc., and the engine load factor. The ECU 0 obtains the current engine load factor by searching the map using the current engine speed, intake pressure, accelerator opening, etc. as keys, or by substituting these into the function and performing calculations.

If the above preconditions are no longer satisfied, both the counters I and II are reset to their minimum values (especially 0) (steps S5 and S6). In addition, the ECU 0 determines that the current value of the counter II has increased to a predetermined value or more (in other words, the counter II has not been reset for a second predetermined time period (for example, 1.3 seconds). (longer than the first predetermined time ), the current engine load factor exceeds the second predetermined value, and the amount of increase in the engine load factor per unit time exceeds the predetermined value. When the specific condition of continuing for more than the time is met (step S3), only the counter II is reset to the minimum value (step S6). The second predetermined value in step S3 corresponds to operation with a load already higher than a certain level, and is a higher value than the first predetermined value in step S1.

It should be noted that the ECU 0 executes correction control for temporarily retarding the ignition timing, and after completing the correction control, when the precondition is not unsatisfied and remains satisfied (step S7), the counter I and counter II are set to their maximum values (step S8).

FIG. 3 shows processing for determining whether or not the ECU 0 should perform correction control for temporarily retarding the ignition timing. The ECU 0 detects that the current engine load factor exceeds a predetermined value (equal to or higher than the first predetermined value) (step S9), and that the amount of increase in accelerator opening per unit time exceeds a predetermined value ( Step S10), when the amount of increase in the engine load factor per unit time exceeds a predetermined value (step S11) and the vehicle is about to accelerate rapidly, other required conditions (for example, the current engine speed is idle) higher than the rotational speed during operation, the current vehicle speed exceeds a predetermined value (5 km/h), the vehicle is running, the coolant temperature of the internal combustion engine is higher than a predetermined value, etc.) is established (step S12), the current value of the counter I is equal to or less than the current value of the counter II (step S13), and the current value of the counter I is still equal to or less than a predetermined value (in other words, the counter I is not reset and continues to increment and decrement). is less than or equal to a first predetermined time (for example, 0.2 seconds) (step S14), corrective control is performed to temporarily retard the ignition timing of the air-fuel mixture (step S15).

The purpose of the first correction control in step S15 is to alleviate the sudden rise of the engine torque when the driver of the vehicle suddenly strongly depresses the accelerator pedal from the state where the accelerator pedal is not depressed. Execution of the correction control in step S15 is permitted when the condition that the current value of the counter I is equal to or less than a predetermined value in step S14 is established, that is, the accelerator opening degree equal to or less than a threshold value close to 0 or 0 is satisfied. exceeds this and the period immediately after the engine load factor exceeds the first predetermined value.

In addition, the ECU 0 determines that the current value of the counter II is lower than the current value of the counter I (step S13), and that the current value of the counter II is still equal to or less than the predetermined value (in other words, the counter II is not reset and cannot be incremented or incremented). When the length of time that the air-fuel mixture continues is less than or equal to a predetermined time (for example, 0.2 seconds) (step S16), correction control is also performed to temporarily retard the ignition timing of the air-fuel mixture (step S17).

The second correction control in step S17 is performed when the driver of the vehicle starts the vehicle by lightly stepping on the accelerator pedal from a state in which the accelerator pedal is not stepped on, and when the driver strongly steps on the accelerator pedal after driving for a certain amount of time, the engine torque increases. The purpose is to curb the rapid increase. A specific condition is established that the current value of the counter II has increased by a predetermined value or more, the current engine load factor exceeds a second predetermined value, and the amount of increase in the engine load factor per unit time exceeds the predetermined value. Then, the counter II is once reset to the minimum value, and as a result, the current value of the counter II falls below the current value of the counter I. Even if the condition of step S14 that the current value of the counter I is equal to or less than the predetermined value is not satisfied, if the condition that the current value of the counter II is equal to or less than the predetermined value is satisfied in step S16, step S17 is performed. Execution of correction control is permitted.

FIG. 4 shows a process of determining whether or not the ECU 0 terminates the correction control for temporarily retarding the ignition timing. When a predetermined time has passed since the execution of the correction control in step S15 or S17 was started (step S18), the ECU 0 determines that the amount of increase in the engine speed per unit time is equal to or less than a predetermined value (step S19), the engine load factor When at least one of conditions such as a deceleration state in which the amount of decrease per unit time is equal to or greater than a predetermined value (step S20) is satisfied, the correction control ends (step S21).

5 and 6 show patterns of correction control performed by the ECU 0 of this embodiment. In the figure, "idle" is ON during idling when the accelerator opening is equal to or less than a threshold value close to 0, and is OFF during non-idling operation when the accelerator opening is equal to 0 or above a threshold close to 0. "Load" is turned ON when the engine load factor exceeds a first predetermined value, and turned OFF when the engine load factor is equal to or less than the first predetermined value. "Idle" and "load" correspond to the preconditions referred to in step S1. "High load during acceleration" turns ON when the engine load factor exceeds a second predetermined value and the amount of increase in engine load factor per unit time exceeds a predetermined value, and turns OFF otherwise. "High load during acceleration" corresponds to the specific condition referred to in step S3. Time _t0 is the time when the engine speed and vehicle speed start to accelerate significantly, time _t1 is the time when the correction control for retarding the ignition timing is started, time _t2 is the time when the correction control is terminated, and time _t3 . is the point in time when the engine speed and vehicle speed are decelerated.

FIG. 5 shows a case in which the driver suddenly depresses the accelerator pedal strongly from a state in which the accelerator pedal is not depressed, and the first correction control in step S15 is performed. On the other hand, FIG. 6 shows the case where the driver depresses the accelerator pedal lightly from the state where the accelerator pedal is not depressed to start the vehicle, and after driving for some time, depresses the accelerator pedal strongly. This is the case where correction control is performed. In the latter, execution of correction control is started at time _t1 when a specific condition is satisfied and the counter II is reset to the minimum value. The time _t1 is later than the time when the precondition that the accelerator opening is not 0 and the engine load factor is greater than that during idling is satisfied.

After time t2 when the condition for ending the correction control is established, the retarded ignition timing is gradually advanced toward _the base timing corresponding to the operating range of the internal combustion engine.

In this embodiment, the accelerator pedal is stepped on from a state where the accelerator opening is 0 or less than a threshold close to 0, the accelerator opening exceeds 0 or a threshold close to 0, and the engine load factor is not low load close to idling. The air-fuel mixture filled in the cylinder 1, provided that the length of time that the state continues is within a predetermined value and that the amount of increase in the engine load factor per unit time exceeds a predetermined value. A first correction control for retarding the ignition timing is performed, and the accelerator opening exceeds a threshold value of 0 or close to 0 without performing the first correction control, and the engine load factor is idling Even if the length of time for which the low-load state continues exceeding a predetermined value, the engine load factor exceeds the predetermined value, and the amount of increase in the engine load factor per unit time exceeds the predetermined value. A control device 0 for an internal combustion engine is configured that performs a second correction control for retarding the ignition timing of the air-fuel mixture charged in the cylinder 1 on the condition that the ignition is continued.

According to this embodiment, even when the driver depresses the accelerator pedal lightly to start the vehicle, runs the vehicle for some time, and then strongly depresses the accelerator pedal, it is possible to perform the second correction control in a timely manner. This second correction control suppresses a rapid increase in engine torque and effectively suppresses a shock to the vehicle body or a jerking phenomenon.

The counter II, which triggers the start of execution of the second correction control, reaches its minimum value unless the current value of the counter II increases to a predetermined value or more and the specific condition that the engine load factor continues to increase does not hold. not reset. While the driver repeatedly depresses and depresses the accelerator pedal, the specific condition is not met, the counter II is not reset, and the second correction control is not performed. Therefore, it is possible to avoid unnecessary continuation of retardation correction of the ignition timing while the vehicle is running. Also, when the driver of a moving vehicle is depressing the accelerator pedal to overtake the preceding vehicle, the engine load factor is already saturated and does not continue to increase. , the second correction control is not performed. Overall, it is possible to ensure a response to the driver's acceleration request.

In addition, in this embodiment, the first correction control is performed on the condition that the engine load factor exceeds the first predetermined value, and the engine load factor exceeds the second predetermined value. The second correction control is performed with this as a necessary condition, and the second predetermined value is set to a higher value than the first predetermined value. As a result, when the accelerator pedal is strongly depressed from the state where the accelerator opening is 0 or less than the threshold close to 0, the first correction control can be quickly performed to suppress the occurrence of shock or hiccups in the vehicle body. When the accelerator pedal is strongly depressed in a state in which the accelerator opening is already opened to some extent, the second correction control can be performed to suppress the shock or jerking of the vehicle body.

The present invention is not limited to the embodiments detailed above. Various modifications can be made to the specific configuration of each part, the procedure of processing, and the like without departing from the scope of the present invention.

INDUSTRIAL APPLICABILITY The present invention can be applied to control of an internal combustion engine mounted on a vehicle.

0... Control unit (ECU)
DESCRIPTION OF SYMBOLS 1... Cylinder 12... Spark plug 3... Intake passage 32... Throttle valve a... Vehicle speed signal b... Crank angle signal c... Accelerator opening signal i... Ignition signal

Claims (2)

The first state is a state in which the accelerator pedal is stepped on from a state where the accelerator opening is 0 or less than a threshold value close to 0, the accelerator opening exceeds 0 or a threshold close to 0, and the engine load factor is not low load close to idling. It continues for a predetermined time or less , and during the first predetermined time during which the state continues, the amount of increase in the engine load factor per unit time exceeds a predetermined value, and the engine load factor exceeds the first predetermined value. and performing a first correction control for retarding the ignition timing of the air-fuel mixture filled in the cylinder on the condition that the cooling water temperature of the internal combustion engine is higher than a predetermined value,
again,
Without executing the first correction control, the accelerator opening exceeds 0 or a threshold close to 0 and the engine load factor is close to idling and not a low load state is longer than the first predetermined time. Ignition timing for the air-fuel mixture charged in the cylinder, on the condition that the engine load factor continues to exceed a second predetermined value and the engine load factor continues to increase. A control device for an internal combustion engine that performs a second correction control for retarding the 2. A control system for an internal combustion engine according to claim 1, wherein said second predetermined value is higher than said first predetermined value.

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