JP4911145B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine, and more particularly to a control device capable of controlling the torque of the internal combustion engine by the valve opening degree and the ignition timing of an intake air amount adjustment valve.

  The torque output from the internal combustion engine can be controlled by the amount of air taken into the cylinder. In order to adjust the intake air amount, a throttle valve is provided in the intake pipe of the internal combustion engine. The intake air amount increases as the throttle valve is opened. However, if the valve opening increases to a certain extent, the intake air amount does not change even if the throttle valve is opened further. The valve opening at this time is the maximum opening that maximizes the intake air amount, and the valve opening of the throttle valve is controlled within the range from this maximum opening to the minimum opening that can maintain the operation of the internal combustion engine. Yes.

However, the maximum opening of the throttle valve that maximizes the intake air amount varies depending on the individual difference of the throttle valve, and also changes over time. As a countermeasure against such an inconvenience, for example, it is conceivable that the valve opening of the throttle valve is fully opened when it is necessary to maximize the intake air amount. For example, Japanese Patent Application Laid-Open No. 2007-255204 discloses a technique for controlling the valve opening of a throttle valve to be fully open when full load operation is required. By fully opening the throttle valve, the intake air amount is surely maximized, and the maximum torque output is guaranteed regardless of individual differences in the throttle valve and changes over time.
JP 2007-255204 A

  Here, the control for changing the valve opening of the throttle valve within the range from the maximum opening to the minimum opening according to the target torque and the target intake air amount is called normal control of the throttle valve. Control for fixing the valve fully open is called throttle valve fully open control. Switching from normal control to full-open control is performed via the maximum opening, but switching from normal control to full-open control is possible if the intake air amount realized at the maximum opening is close to the maximum intake air amount. There is no sudden change in the intake air volume.

  However, since the throttle valve has individual differences and changes with time as described above, the intake air amount realized at the maximum opening is not necessarily the maximum intake air amount. When the intake air amount changes suddenly when switching from normal control to full open control, the torque output from the internal combustion engine also changes suddenly. The occurrence of such a torque step deteriorates drivability.

  The present invention has been made to solve the above-described problems, and is a control device for an internal combustion engine that can suppress a torque step caused by a sudden change in the intake air amount when switching from normal control to full-open control. The purpose is to provide.

In order to achieve the above object, a first invention provides a control apparatus for an internal combustion engine capable of controlling torque by the valve opening and ignition timing of an intake air amount adjusting valve for adjusting an intake air amount.
Target torque setting means for setting a target torque of the internal combustion engine;
A means for determining whether or not to open the valve opening of the intake air amount adjustment valve, and a fully open determining means for making the target torque equal to or greater than a predetermined fully open reference torque;
When the fully open condition is satisfied, the valve opening of the intake air amount adjusting valve is fully opened, and when the fully open condition is not satisfied, the valve opening of the intake air amount adjusting valve is set according to the magnitude of the target torque. A valve opening control means for changing;
Estimated torque calculating means for calculating an estimated torque of the internal combustion engine based on an intake air amount realized at a current valve opening of the intake air amount adjusting valve;
Ignition timing control means for retarding the ignition timing so as to compensate for the torque difference when the estimated torque exceeds the target torque,
When the ignition timing is retarded when the fully open condition is satisfied, the valve opening control means gradually changes the valve opening of the intake air amount adjustment valve from the fully opened opening to the closing direction. It is characterized by letting.

According to a second invention, in the first invention,
The valve opening control means gradually changes the valve opening of the intake air amount adjusting valve from the fully opened position to the closing direction when the delay of the ignition timing under the fully opened condition continues for a predetermined time. It is characterized by that.

According to a third invention, in the first or second invention,
The target torque is set based on the maximum torque that can be output by the internal combustion engine, and the fully open reference torque is set based on the maximum torque,
Learning means for learning a correction value of the maximum torque based on a difference between the estimated torque and the maximum torque when a retard of ignition timing occurs when the fully open condition is satisfied. It is characterized by.

According to a fourth aspect of the present invention, there is provided a control device for an internal combustion engine capable of controlling a torque by a valve opening degree and an ignition timing of an intake air amount adjusting valve for adjusting an intake air amount in order to achieve the above object.
Target torque setting means for setting a target torque of the internal combustion engine with reference to a maximum torque that can be output by the internal combustion engine;
A means for determining whether or not to open the valve opening of the intake air amount adjusting valve, wherein the target torque is a fully open condition that the target torque is not less than a fully open reference torque set based on the maximum torque. Means,
When the fully open condition is satisfied, the valve opening of the intake air amount adjusting valve is fully opened, and when the fully open condition is not satisfied, the valve opening of the intake air amount adjusting valve is set according to the magnitude of the target torque. A valve opening control means for changing;
Estimated torque calculating means for calculating an estimated torque of the internal combustion engine based on an intake air amount realized at a current valve opening of the intake air amount adjusting valve;
Ignition timing control means for retarding the ignition timing so as to compensate for the torque difference when the estimated torque exceeds the target torque;
Learning means for learning a correction value of the maximum torque based on a difference between the estimated torque and the maximum torque when a retard of ignition timing occurs when the fully open condition is satisfied;
It is characterized by having.

A fifth invention is the fourth invention,
The learning means learns the correction value of the maximum torque when the retardation of the ignition timing under the fully opened condition continues for a predetermined time.

  According to the first invention, the estimated torque calculated based on the intake air amount realized at the fully opened position, even if the intake air amount suddenly increases when the valve opening degree of the intake air amount adjusting valve is fully opened. When the engine exceeds the target torque, the ignition timing is retarded so as to compensate for the torque difference, so that the torque step due to the sudden increase in the intake air amount is suppressed. Further, after that, by gradually changing the valve opening of the intake air amount adjusting valve from the fully opened opening to the closing direction, the ignition timing is returned to the advance side by the amount of reduction of the intake air amount. Thereby, the deterioration of the fuel consumption caused by the retard of the ignition timing is suppressed. That is, according to the first aspect of the invention, the torque level difference that occurs when the valve opening of the intake air amount adjustment valve is switched to full open can be suppressed by retarding the ignition timing, and also caused by retarding the ignition timing. Deterioration of fuel consumption can be suppressed by changing the valve opening from the fully open position to the closing direction and returning the ignition timing to the advance side accordingly.

  According to the second invention, the valve opening is changed from the fully opened position to the closing direction on the condition that the ignition delay under the fully opened condition is continued for a predetermined time. By excluding the ignition delay due to the temporary deviation, it is possible to prevent the occurrence of a steady ignition delay during the full opening control.

  According to the third invention, when the ignition timing is retarded when the fully-open condition is satisfied, the correction value of the maximum torque is learned based on the difference between the estimated torque and the maximum torque. The target torque is set based on the corrected maximum torque. According to this, since the estimated torque does not exceed the target torque when the valve opening degree of the intake air amount adjustment valve is fully opened, the ignition timing is not retarded from the next time. Therefore, deterioration of fuel consumption due to the retard of the ignition timing is prevented, and the fully opened position can be maintained as it is, so that the output of the maximum torque can be ensured. In addition, since the fully open reference torque is set based on the maximum torque corrected by the correction value after the next time, sudden changes in the intake air amount before and after the valve opening is fully opened can be suppressed.

  According to the fourth aspect of the invention, even if the intake air amount suddenly increases when the valve opening of the intake air amount adjustment valve is fully opened, it is calculated based on the intake air amount realized at the fully open opening. When the estimated torque exceeds the target torque, the ignition timing is retarded so as to compensate for the torque difference, so that the torque step due to the sudden increase in the intake air amount is suppressed. Further, the correction value of the maximum torque is learned based on the difference between the estimated torque and the maximum torque, and the target torque is set based on the maximum torque corrected by the correction value from the next time onward. According to this, since the estimated torque does not exceed the target torque when the valve opening degree of the intake air amount adjustment valve is fully opened, the ignition timing is not retarded from the next time. Therefore, the deterioration of fuel consumption due to the retard of the ignition timing is prevented, and the fully open position can be maintained, so that the output of the maximum torque can be ensured. In addition, since the fully open reference torque is set based on the maximum torque corrected by the correction value after the next time, sudden changes in the intake air amount before and after the valve opening is fully opened can be suppressed.

  According to the fifth aspect of the present invention, learning of the correction value of the maximum torque is performed on the condition that the ignition delay under the fully open condition is continued for a predetermined time, so that the maximum torque and the target torque that can be actually realized are It is possible to accurately learn the deviation from the maximum torque that is set as a reference.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 4.

  FIG. 1 is a block diagram showing a configuration of a control device for an internal combustion engine as the first embodiment of the present invention. The control device of the present embodiment is configured as a torque demand type control device that controls the intake air amount and the ignition timing in a coordinated manner so that the target torque is set and the target torque is realized. As an intake air amount adjustment valve that adjusts the intake air amount, the internal combustion engine according to the present embodiment includes a throttle valve 2 disposed in an intake pipe. Hereinafter, the configuration of the control device for controlling the operation of the slot valve 2 and the function thereof will be described.

  The target torque is set by the target torque setting unit 4. An accelerator opening signal from an accelerator opening sensor (not shown) is input to the target torque setting unit 4. The accelerator opening signal is a signal reflecting the driver's accelerator operation, and the driver's torque request is included in the accelerator opening signal. The target torque setting unit 4 converts the input accelerator opening signal into the driver's request magnitude (represented by the driver request rate,%), and the internal combustion engine is operated under the current engine speed and valve timing. The driver request torque is calculated based on the maximum torque that can be output and the driver request rate. The maximum torque that can be output by the internal combustion engine is calculated from a map that uses engine speed and valve timing as parameters.

  The target torque setting unit 4 also receives signals from other control systems such as VSC (Vehicle Stability Control system) and TRC (Traction Control system). When the torque request is included in the signals from these control systems, the target torque setting unit 4 calculates the torque necessary for each control and obtains it as the other control request torque. And the target torque setting part 4 sets the value which added other control request torque to the above-mentioned driver request torque as a final target torque.

  Next, the control device converts the target torque into a target air amount. This conversion work is performed by the target air amount calculation unit 6. The target air amount calculation unit 6 converts the target torque into the intake air amount using the air amount map. The air amount map is a multi-dimensional map with a plurality of parameters including target torque as axes, and various operating states that affect the relationship between torque and intake air amount, such as ignition timing, engine speed, A / F, etc. And operating conditions are used as parameters. Although current values are input to these parameters, the ignition timing is the optimum ignition timing (ignition timing on either the MBT or the trace knock ignition timing). The target air amount calculation unit 6 calculates the intake air amount converted from the target torque as the target air amount of the engine.

  Next, the control device converts the target air amount into the valve opening of the throttle valve 2. This conversion work is performed by the target valve opening calculation unit 8. The target valve opening calculation unit 8 converts the target air amount into the throttle valve opening using an inverse model of an intake system model (air model). That is, the throttle valve opening that can realize the target air amount is calculated. The intake system model is a model of the response of the intake air amount to the operation of the throttle valve based on fluid dynamics and the like, which is expressed by a mathematical formula. By inputting the intake air amount to the inverse model of the intake system model, the operation of the throttle valve for realizing the intake air amount can be derived. The target valve opening calculation unit 8 calculates the throttle valve opening converted from the target air amount as the target valve opening of the throttle valve 2.

  The target valve opening degree of the throttle valve 2 calculated by the target valve opening degree calculation unit 8 is output to the throttle valve 2 via the throttle valve opening degree control unit 10. The throttle valve opening control unit 10 switches the control content of the throttle valve 2 in response to the fully open permission / prohibition signal. When the full-open prohibition signal is input, the throttle valve opening control unit 10 changes the valve opening of the throttle valve 2 according to the target valve opening calculated by the target valve opening calculation unit 8. On the other hand, when the fully open permission signal is input, the throttle valve opening control unit 10 controls the valve opening of the throttle valve 2 to fully open. By fully opening the throttle valve 2, it is possible to reliably maximize the intake air amount regardless of individual differences of the throttle valve 2 and changes with time, and as a result, it is possible to ensure the maximum torque of the internal combustion engine.

  The throttle valve opening control unit 10 has other characteristic functions in addition to the functions described above. The characteristic function is a function that works when a predetermined condition is satisfied in a situation where the fully open permission signal is input, and this will be described in detail later.

  The full open permission / prohibition signal is issued by the full open determination unit 12. The fully open determination unit 12 has a function of determining success or failure of a condition for controlling the throttle valve 2 to be fully open (hereinafter, fully open condition). The full open determination unit 12 determines that the full open condition is satisfied when the target torque set by the target torque setting unit 4 is equal to or greater than the full open reference torque. When the fully open condition is satisfied, the fully open determination unit 12 switches the signal supplied to the throttle valve opening control unit 10 from the fully open prohibition signal to the fully open permission signal. The fully open reference torque is a value obtained by multiplying the maximum torque of the internal combustion engine by a predetermined coefficient less than 1, and is set to a value close to the maximum torque. By fully opening the valve opening after the target torque is close to the maximum torque, it is possible to reliably output the maximum torque while preventing the occurrence of a torque step. The maximum torque used here is the maximum torque that can be output under the current operating conditions, and is calculated from a map that uses the engine speed and the valve timing of the intake and exhaust valves as parameters.

  Next, the ignition timing control performed in this embodiment will be described. An actuator used for ignition timing control is the ignition device 20, and an ignition timing (expressed by a crank angle) based on TDC is used as an operation amount. The control device calculates the ignition timing in the ignition timing calculation unit 26 and sets it in the ignition timing control unit 28.

  Torque efficiency is used to calculate the ignition timing in the ignition timing calculation unit 28. The torque efficiency is a ratio of the target torque to the estimated torque of the internal combustion engine, and is calculated by the torque efficiency calculation unit 24. The estimated torque is a torque obtained when the ignition timing is set to the optimum ignition timing based on the current throttle valve opening, and is calculated by the estimated torque calculation unit 22 described below. The torque efficiency calculation unit 24 divides the target torque set by the target torque setting unit 4 by the estimated torque, and calculates the calculation result as torque efficiency.

  In calculating the estimated torque, the estimated torque calculating unit 22 first calculates the intake air amount estimated to be realized with the current valve opening of the throttle valve 2. The forward model of the intake system model described above is used for calculating the estimated air amount. In addition, the air flow rate in the intake pipe measured by the air flow sensor is used as correction data for the calculation using the intake system model.

  Next, the estimated torque calculation unit 22 converts the calculated estimated air amount into torque. A torque map is used to convert the estimated air amount into torque. The torque map is the reverse of the input / output of the air amount map described above, and there are various operating conditions and operating conditions that affect the relationship between torque and intake air amount, such as ignition timing, engine speed, A / F, etc. Used as a parameter. Although current values are input to these parameters, the ignition timing is set to the optimum ignition timing. The estimated torque calculation unit 22 calculates the torque converted from the estimated air amount as the estimated torque at the optimal ignition timing.

  The ignition timing calculation unit 26 calculates an ignition delay amount with respect to the optimal ignition timing from the input torque efficiency. An ignition timing map is used to calculate the ignition retard amount. The ignition timing map is a multidimensional map with a plurality of parameters including torque efficiency as axes, and various operating conditions that affect the determination of the ignition timing, such as engine speed, are used as parameters. In the ignition timing map, the ignition delay amount when the torque efficiency is 1 or more is set to zero, and the smaller the torque efficiency is, the larger the ignition delay amount is set. Therefore, when there is a difference between the estimated torque and the target torque, an ignition delay amount is calculated for compensating the torque difference by torque adjustment based on the ignition timing retardation. The ignition timing calculation unit 26 calculates the final ignition timing from the ignition delay amount determined using the ignition timing map and the optimal ignition timing determined from the operating state of the internal combustion engine, and sends it to the ignition timing control unit 28. set.

  The ignition timing control based on the target torque is performed by the series of processes described above. According to such ignition timing control, a change in the target torque that cannot be dealt with by adjusting the intake air amount can be compensated by adjusting the ignition timing, so that a high target torque realization accuracy can be obtained.

  Further, such ignition timing control is also effective for a sudden increase in the intake air amount when the valve opening of the throttle valve 2 is fully opened. As described above, the throttle valve 2 is fully opened at the fully open reference torque. If the intake air amount obtained by the valve opening at that time is close to the maximum air amount, the intake air amount associated with the full opening of the throttle valve 2 is reduced. There is no sudden change. However, since the throttle valve 2 has individual differences and changes with time, the intake air amount corresponding to the fully open reference torque is not necessarily close to the maximum intake air amount. If the intake air amount changes suddenly when the throttle valve 2 is fully opened, the torque output from the internal combustion engine may also change suddenly. With regard to such a problem, in the present embodiment, when the estimated torque calculated based on the intake air amount realized at the fully opened opening degree exceeds the target torque, the ignition timing is automatically set so as to compensate for the torque difference. Be retarded.

  FIG. 2 is a graph showing changes over time in the target torque, estimated torque, throttle valve opening, and ignition timing immediately before and after the throttle valve 2 is fully opened. As shown in this figure, when the target torque exceeds the fully open reference torque, the valve opening of the throttle valve 2 is fully opened. As a result, the intake air amount increases rapidly, but the ignition timing is retarded so as to compensate for the torque difference between the estimated torque calculated from the intake air amount and the target torque. Is suppressed.

  However, one problem arises here. As shown in FIG. 2, the estimated torque calculated based on the throttle valve opening exceeds the “maximum torque”. As described above, the maximum torque of the internal combustion engine is calculated from the map based on the engine speed and the like, and the target torque is set based on the maximum torque. Although the map is created based on actual measurement data, there are individual differences and secular changes in the internal combustion engine. For this reason, it is sufficiently possible that the estimated torque calculated from the intake air amount when fully opened is larger than the maximum torque obtained from the map. In this case, while the throttle valve 2 is fully opened, a steady torque difference occurs between the estimated torque and the target torque (maximum torque), and the ignition timing is retarded to compensate for the torque difference. Will continue.

  The retard of the ignition timing is not preferable because it lowers the efficiency of the internal combustion engine and deteriorates the fuel consumption. Therefore, the control device of the present embodiment has a characteristic function in the throttle valve opening control unit 10. Hereinafter, this characteristic function will be described with reference to FIGS.

  The flowchart of FIG. 3 shows a control routine that is executed when the fully open condition is satisfied. When the fully open condition is satisfied in the fully open determination unit 12, the control device executes the routine shown in the flowchart of FIG. 3 at a constant cycle.

  In the first step S102 of the routine shown in FIG. 3, it is determined whether or not an ignition retardation for torque control has occurred due to the fully open control of the throttle valve 2. Whether or not an ignition delay for torque control has occurred is determined by the presence or absence of an ignition delay amount calculated by the ignition timing calculation unit 26 or a torque efficiency value calculated by the torque efficiency calculation unit 24 is 1. It can be judged by whether it is less than. If no ignition retardation has occurred, this routine ends.

  When the ignition retardation has occurred, the determination in step S104 is subsequently performed. In step S104, it is determined whether or not the state where the ignition timing is retarded continues for a predetermined time. The problem here is that the ignition timing is always retarded, and the temporary ignition timing is excluded. If there is no deviation between the maximum torque calculated from the map and the maximum torque that can actually be achieved, the estimated torque reaches its peak at the maximum torque and eventually matches the target torque, so the ignition timing automatically advances. It is returned to the corner side. On the other hand, when the maximum torque actually realizable is larger than the maximum torque calculated from the map, a steady ignition delay occurs due to the difference between the estimated torque and the target torque.

  If the ignition delay is not continued for a predetermined time, this routine ends. However, if the ignition timing is delayed for a predetermined time, the process of step S106 is performed. In step S106, the throttle valve opening control unit 10 performs a process for gradually changing the valve opening of the throttle valve 2 from the fully opened position to the closing direction. Specifically, the throttle valve opening control unit 10 calculates a valve opening correction amount ΔTA from a map using the engine speed as a parameter. Then, the throttle valve 2 is controlled with a value obtained by reducing the current valve opening TA by the valve opening correction amount ΔTA as a target valve opening.

  FIG. 4 illustrates the execution result of the above routine. FIG. 4 shows changes over time in the target torque, estimated torque, throttle valve opening, and ignition timing immediately before and after the throttle valve 2 is fully opened. As shown in FIG. 4, when the target torque reaches the fully open reference torque (time point t1), the throttle valve opening is fully opened. As a result, the estimated torque increases as the intake air amount increases, and a difference occurs between the estimated torque and the target torque. The ignition timing is retarded so as to eliminate this torque difference.

  Then, when a predetermined time elapses (time t2) from the time when the ignition timing is retarded (time t1), the valve opening of the throttle valve 2 is gradually controlled from the fully opened position to the closing direction. As a result, the estimated torque decreases as the intake air amount decreases, and the torque difference between the estimated torque and the target torque also decreases. Along with this, the ignition timing is returned to the advance side, and eventually the ignition delay amount becomes zero when the estimated torque coincides with the target torque. When the ignition retard amount becomes zero, the determination result in step S102 of the above routine is No, and the control in the closing direction of the throttle valve 2 performed in step S106 is completed.

  As is clear from the comparison between FIG. 2 and FIG. 4, if the routine shown in FIG. 3 is executed when the fully open condition is satisfied, the valve opening of the throttle valve 2 is changed from the fully open position to the closing direction, and the corresponding amount The ignition timing can be returned to the advance side. As a result, it is possible to suppress the deterioration in fuel consumption caused by the retard of the ignition timing while suppressing the torque step generated when the valve opening of the throttle valve 2 is switched to the fully open state.

  The control device as the first embodiment of the present invention has been described above. The correspondence relationship between the first embodiment and the present invention is as follows.

  In the configuration shown in FIG. 1, the target torque setting unit 4 corresponds to “target torque setting means” of the first invention. The full open determination unit 12 corresponds to the “full open determination unit” of the first invention. The estimated torque calculator 22 corresponds to the “estimated torque calculator” of the first invention. Further, the torque efficiency calculation unit 24, the ignition timing calculation unit 26, and the ignition timing control unit 28 constitute the “ignition timing control means” of the first invention. The target air amount calculator 6, the target valve opening calculator 8 and the throttle valve opening controller 10 constitute the “valve opening controller” of the first and second inventions.

Embodiment 2. FIG.
Embodiment 1 of the present invention will be described with reference to FIGS.

  FIG. 5 is a block diagram showing the configuration of the control device for the internal combustion engine as the first embodiment of the present invention. The control device of the present embodiment is a torque demand type control device as in the first embodiment, and is configured so as to be able to perform full-open control for fully opening the valve opening of the throttle valve 2 as in the first embodiment. Yes. In the configuration shown in FIG. 5, elements that are the same as those in the first embodiment are given the same reference numerals.

  The control device of the present embodiment is obtained by adding a new function to the control device of the first embodiment. The function added in the present embodiment is a function that corrects the “maximum torque” that serves as a reference for setting the target torque and also serves as a reference for the fully open reference torque. As described in the first embodiment, the maximum torque that can be output by the internal combustion engine is stored in the map in association with the engine speed and the valve timing. However, although the map is created based on actual measurement data, the internal combustion engine has individual differences and aging, so the maximum torque that can actually be realized may be larger than the maximum torque calculated from the map. . Since the target torque is set based on the maximum torque calculated from the map, when the throttle valve 2 is fully open, the estimated torque (maximum torque that can be actually realized) and the target torque (maximum torque calculated from the map) There is a difference between them, and the ignition timing is retarded according to the torque difference. For this reason, in the present embodiment, the relationship between the maximum torque stored in the map and the engine speed is corrected to a value that matches the actual relationship, thereby preventing the occurrence of unnecessary ignition delay. Decided to prevent.

  The function of correcting the maximum torque is realized by including a correction value learning unit 32 in addition to the maximum torque calculation unit 30. The maximum torque calculator 30 has a map that defines the relationship between the maximum torque and the engine speed, and calculates the maximum torque that the internal combustion engine can output under the current operating conditions based on the map. The maximum torque obtained by the maximum torque calculation unit 30 is supplied to the target torque setting unit 4 and the full open determination unit 12. The target torque setting unit 4 sets the target torque based on the maximum torque supplied from the maximum torque calculation unit 30. Further, the full open determination unit 12 calculates the full open reference torque by multiplying the maximum torque supplied from the maximum torque calculation unit 30 by a predetermined coefficient. Although illustration as a component is omitted in FIG. 1, the function of the maximum torque calculation unit 30 is also provided in the control device of the first embodiment.

  The correction value learning unit 32 learns the correction value of the maximum torque based on the difference between the estimated torque and the maximum torque at that time when the ignition delay occurs when the fully open condition is satisfied. The correction value is learned for each learning region defined by the engine speed or the like. The correction value may be the difference between the estimated torque and the maximum torque when the learning condition is satisfied, or the difference multiplied by a learning coefficient less than 1. The correction value learned by the correction value learning unit 32 is reflected in the calculation of the maximum torque in the maximum torque calculation unit 30. From the next time onward, the maximum torque corrected by the correction value is supplied to the target torque setting unit 4 and the fully open determination unit 12.

  The flowchart of FIG. 6 shows a control routine executed when the fully open condition is satisfied in the present embodiment. The above-described maximum torque correction is performed in the course of executing this routine. When the fully open condition is satisfied in the fully open determination unit 12, the control device executes the routine shown in the flowchart of FIG. 6 at a constant cycle.

  In the first step S202 of the routine shown in FIG. 6, it is determined whether or not an ignition retardation for torque control has occurred due to the fully open control of the throttle valve 2. If no ignition retardation has occurred, this routine ends.

  When the ignition retardation has occurred, the determination in step S204 is subsequently performed. In step S204, it is determined whether the state where the ignition timing is retarded continues for a predetermined time. If the ignition delay does not continue for a predetermined time, this routine ends.

  When the ignition timing is retarded for a predetermined time, steps S206 and S208 are performed. In step S206, a difference between the estimated torque currently calculated by the estimated torque calculation unit 22 and the maximum torque calculated from the map based on the engine speed or the like is calculated, and correction of the maximum torque is performed based on the difference. The value is learned. Then, the learning value of the correction value is stored in a learning area corresponding to the current engine speed or the like among a plurality of learning areas defined by the engine speed or the like. Note that the process of step S206 is executed only when the determination of step S204 is first established, and the process of step S206 is skipped for the second time and thereafter.

  In the next step S208, the throttle valve opening control unit 10 calculates the valve opening correction amount ΔTA from the map using the engine speed as a parameter, and reduces the current valve opening TA by the valve opening correction amount ΔTA. The throttle valve 2 is controlled using the obtained value as the target valve opening. As a result, the valve opening of the throttle valve 2 gradually changes from the fully opened position to the closing direction.

  FIG. 7 is a diagram showing temporal changes in the target torque, estimated torque, throttle valve opening, and ignition timing in the full-open control after the above-described routine is executed, that is, after the maximum torque is corrected. Hereinafter, the effect obtained by correcting the maximum torque will be described in more detail with reference to FIG. In addition, each time change of the target torque, the estimated torque, the throttle valve opening degree, and the ignition timing before the correction of the maximum torque is as shown in FIG. 4 as in the first embodiment. Since this has already been described in the first embodiment, a description thereof is omitted here.

  As shown in FIG. 7, the valve opening of the throttle valve 2 is fully opened when the target torque reaches the fully open reference torque (time point t1). However, since the fully open reference torque is also corrected to the large torque side with the correction of the maximum torque, the valve opening when the valve opening of the throttle valve 2 is switched to the fully open state shifts to the large opening side. Yes. That is, the difference in the valve opening before and after the full open control is reduced by correcting the maximum torque. As a result, the difference in the intake air amount before and after the valve opening is switched to full open is suppressed, and the ignition retard amount for absorbing the torque step can be small.

  Further, since the target torque is set based on the corrected maximum torque, the estimated torque does not exceed the target torque when the throttle valve opening is fully opened. That is, the estimated torque eventually converges to the maximum torque and matches the target torque. As a result, the ignition timing is temporarily retarded, but is immediately returned to the advance side. That is, in the full opening control after the maximum torque is corrected, the ignition delay can be eliminated without performing an operation of gradually closing the throttle valve opening from the full opening. Therefore, according to the control device of the present embodiment, not only can the deterioration of fuel consumption due to the retard of the ignition timing be prevented, but the internal combustion engine can truly output by maintaining the valve opening of the throttle valve 2 fully open. Maximum torque can be guaranteed.

  The control apparatus as the second embodiment of the present invention has been described above. The correspondence between the second embodiment and the present invention is as follows.

  In the configuration shown in FIG. 5, the target torque setting unit 4 corresponds to “target torque setting means” of the first and fourth inventions. The full open determination unit 12 corresponds to the “full open determination means” of the first and fourth inventions. The estimated torque calculation unit 22 corresponds to the “estimated torque calculation means” of the first and fourth inventions. The torque efficiency calculation unit 24, the ignition timing calculation unit 26, and the ignition timing control unit 28 constitute "ignition timing control means" according to the first and fourth aspects of the invention. The target air amount calculation unit 6, the target valve opening calculation unit 8, and the throttle valve opening control unit 10 constitute the “valve opening control means” of the first, second, and fourth inventions. The correction value learning unit 32 corresponds to the “learning means” of the fourth and fifth inventions.

Others.
The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the internal combustion engine provided with the throttle valve is the control target, but the internal combustion engine that can be controlled by the control device of the present invention is not limited to this. The throttle valve is an example of an intake air amount adjusting valve that adjusts the engine intake air amount, and the intake air amount adjusting valve may be an intake valve having a continuous VVL that can continuously change the lift amount.

It is a block diagram which shows the structure of the control apparatus of the internal combustion engine as Embodiment 1 of this invention. It is a figure for demonstrating a problem in case throttle valve full open control is performed in torque demand control. It is a flowchart which shows the routine of control performed when fully open conditions are satisfied in Embodiment 1 of this invention. It is a figure for demonstrating the effect when the routine shown in FIG. 3 is performed. It is a block diagram which shows the structure of the control apparatus of the internal combustion engine as Embodiment 2 of this invention. It is a flowchart which shows the routine of control performed when fully open conditions are satisfied in Embodiment 2 of this invention. It is a figure for demonstrating the effect when the routine shown in FIG. 6 is performed.

Explanation of symbols

2 throttle valve 4 target torque setting unit 6 target air amount calculation unit 8 target valve opening calculation unit 10 throttle valve opening control unit 12 full open determination unit 14 atmospheric pressure learning completion determination unit 20 ignition device 22 estimated torque calculation unit 24 torque efficiency Calculation unit 26 Ignition timing calculation unit 28 Ignition timing control unit 30 Maximum torque calculation unit 32 Correction value learning unit

Claims (5)

In a control device for an internal combustion engine capable of controlling torque by the valve opening and ignition timing of an intake air amount adjustment valve that adjusts the intake air amount,
Target torque setting means for setting a target torque of the internal combustion engine;
A means for determining whether or not to open the valve opening of the intake air amount adjustment valve, and a fully open determining means for making the target torque equal to or greater than a predetermined fully open reference torque;
When the fully open condition is satisfied, the valve opening of the intake air amount adjusting valve is fully opened, and when the fully open condition is not satisfied, the valve opening of the intake air amount adjusting valve is set according to the magnitude of the target torque. A valve opening control means for changing;
Estimated torque calculating means for calculating an estimated torque of the internal combustion engine based on an intake air amount realized at a current valve opening of the intake air amount adjusting valve;
Ignition timing control means for retarding the ignition timing so as to compensate for the torque difference when the estimated torque exceeds the target torque,
When the ignition timing is retarded when the fully open condition is satisfied, the valve opening control means gradually changes the valve opening of the intake air amount adjustment valve from the fully opened opening to the closing direction. A control device for an internal combustion engine, characterized by comprising:   The valve opening control means gradually changes the valve opening of the intake air amount adjusting valve from the fully opened position to the closing direction when the delay of the ignition timing under the fully opened condition continues for a predetermined time. The control apparatus for an internal combustion engine according to claim 1. The target torque is set based on the maximum torque that can be output by the internal combustion engine, and the fully open reference torque is set based on the maximum torque,
Learning means for learning a correction value of the maximum torque based on a difference between the estimated torque and the maximum torque when a retard of ignition timing occurs when the fully open condition is satisfied. The control apparatus for an internal combustion engine according to claim 1 or 2, characterized by the above-mentioned. In a control device for an internal combustion engine capable of controlling torque by the valve opening and ignition timing of an intake air amount adjustment valve that adjusts the intake air amount,
Target torque setting means for setting a target torque of the internal combustion engine with reference to a maximum torque that can be output by the internal combustion engine;
A means for determining whether or not to open the valve opening of the intake air amount adjusting valve, wherein the target torque is a fully open condition that the target torque is not less than a fully open reference torque set based on the maximum torque. Means,
When the fully open condition is satisfied, the valve opening of the intake air amount adjusting valve is fully opened, and when the fully open condition is not satisfied, the valve opening of the intake air amount adjusting valve is set according to the magnitude of the target torque. A valve opening control means for changing;
Estimated torque calculating means for calculating an estimated torque of the internal combustion engine based on an intake air amount realized at a current valve opening of the intake air amount adjusting valve;
Ignition timing control means for retarding the ignition timing so as to compensate for the torque difference when the estimated torque exceeds the target torque;
Learning means for learning a correction value of the maximum torque based on a difference between the estimated torque and the maximum torque when a retard of ignition timing occurs when the fully open condition is satisfied;
A control device for an internal combustion engine, comprising:   5. The control device for an internal combustion engine according to claim 4, wherein the learning means learns the correction value of the maximum torque when the retardation of the ignition timing under the fully opened condition continues for a predetermined time. .

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