JP2010090813A - Internal combustion engine control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine control system by which an unnecessary retard for ignition timing is restrained in controlling the engine so as to cause an actual torque of the engine to follow a command torque. <P>SOLUTION: In controlling the internal combustion engine, if specified operation conditions are established for allowing retard restriction on ignition timing, and at the same time, either of a rate of change of the command torque and a rate of change of estimated torque is negative, then, the amount of retard of the ignition timing is set at zero, even in such a state that the estimated torque is higher than the command torque. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for an internal combustion engine. More specifically, when the estimated torque when the ignition timing is set to the optimal ignition timing is larger than the target torque, the ignition timing is set so that the actual torque of the internal combustion engine approaches the target torque. The present invention relates to a control device for an internal combustion engine that retards the angle.

  As a method of controlling the torque of the internal combustion engine, the throttle is operated based on the target torque, the estimated torque realized under the optimum ignition timing is calculated from the actual throttle opening, and the estimated torque and the target torque are calculated. A method for adjusting the ignition timing in accordance with the deviation (hereinafter, a conventional method) is known. According to the conventional method, the actual torque of the internal combustion engine can be changed following the target torque.

  However, the conventional method has the following problems.

  In the process until the target torque is reflected in the estimated torque, various response delays such as a delay in calculation processing and signal transmission within the control device, a delay in the operation of the throttle, or a response delay in the sensor occur. In some cases, a certain delay time is provided from the setting of the throttle opening to the output timing of the command signal to the throttle. For this reason, there is always a time lag between the target torque and the estimated torque.

  A time lag between the target torque and the estimated torque causes a problem when the target torque changes, particularly when the target torque decreases. For example, when the target torque is reduced as shown in FIG. 5, the estimated torque is also reduced following that. At this time, a time lag accompanying delay control or the like appears as a phase lag between the target torque and the estimated torque. As a result, a period in which the estimated torque is larger than the target torque temporarily occurs.

  According to the conventional method, when the estimated torque is larger than the target torque, the ignition timing is retarded with respect to the optimum ignition timing. Such retarding of the ignition timing is automatically performed even when operation at the optimal ignition timing is required. That is, in the conventional method, the ignition timing is retarded even though it is not intended, and as a result, fuel consumption may be deteriorated.

Regarding the above-described problems in the conventional method, Japanese Patent Application Laid-Open No. 2008-155104 discloses a technique as a solution. In the control apparatus for an internal combustion engine described in Japanese Patent Application Laid-Open No. 2008-155104, when the change rate of the target torque is negative, the retard of the ignition timing is limited. According to this, an unnecessary retardation of the ignition timing when the target torque is reduced can be suppressed.
JP 2008-151054 A

  However, there is still room for improvement in the control device described in Japanese Patent Application Laid-Open No. 2008-155104. The unnecessary retard of the ignition timing is a problem that occurs when the estimated torque temporarily becomes larger than the target torque as the target torque decreases, but it is estimated that the target torque change rate is negative. This is because there is a difference between the period in which the torque is temporarily larger than the target torque. This deviation becomes particularly noticeable when throttle delay control is performed.

  The present invention has been made to solve the above-described problems, and suppresses an unnecessary retard of the ignition timing when controlling the internal combustion engine so that the actual torque of the internal combustion engine follows the target torque. 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 achieve the above object, a first aspect of the present invention is a control device for an internal combustion engine capable of controlling torque by the opening degree of an intake air amount adjustment valve and ignition timing.
Target torque setting means for setting the target torque;
An intake air amount adjusting valve operating means for operating the intake air amount adjusting valve based on the target torque;
Estimated torque calculating means for calculating a torque obtained when the ignition timing is set to the optimal ignition timing (hereinafter, estimated torque) based on the actual opening of the intake air amount adjusting valve;
An ignition timing retarding means for retarding an ignition timing so that an actual torque of the internal combustion engine approaches the target torque when the estimated torque is larger than the target torque;
Target torque change rate calculating means for calculating a change rate of the target torque;
Estimated torque change rate estimating means for calculating a change rate of the estimated torque;
The ignition timing is satisfied when a predetermined operating condition that allows the retard of the ignition timing is satisfied and either the rate of change of the target torque or the rate of change of the estimated torque is negative. Retardation limiting means for limiting the retardation of the ignition timing by the retardation means;
It is characterized by having.

According to a second invention, in the first invention,
The predetermined operating condition includes that a request for retarding the ignition timing is not issued from a host control device that controls the entire drive system of the vehicle.

According to a third invention, in the first or second invention,
The predetermined operating condition includes that the temperature of the exhaust purification catalyst disposed in the exhaust passage of the internal combustion engine exceeds a predetermined overheat determination temperature.

A fourth invention is any one of the first to third inventions,
The estimated torque change rate calculating means calculates a change rate of a signal obtained by passing the estimated torque through a low-pass filter.

Further, a fifth aspect of the invention is a control device for an internal combustion engine capable of controlling torque by the opening degree of the intake air amount adjustment valve and the ignition timing.
Target torque setting means for setting the target torque;
An intake air amount adjusting valve operating means for operating the intake air amount adjusting valve based on the target torque;
Estimated torque calculating means for calculating a torque obtained when the ignition timing is set to the optimal ignition timing (hereinafter, estimated torque) based on the actual opening of the intake air amount adjusting valve;
An ignition timing retarding means for retarding an ignition timing so that an actual torque of the internal combustion engine approaches the target torque when the estimated torque is larger than the target torque;
Estimated torque change rate estimating means for calculating a change rate of the estimated torque;
When predetermined operating conditions permitting the restriction of the ignition timing retardation are satisfied and the rate of change of the estimated torque is negative, the ignition timing retardation by the ignition timing retardation means is reduced. A retard angle limiting means for limiting,
It is characterized by having.

  According to the first invention, the estimated torque calculated based on the actual opening of the intake air amount adjusting valve changes following the change in the target torque. Therefore, when the target torque decreases, the target torque decreases. The estimated torque starts to decrease with a delay, and the decrease in the estimated torque stops with a delay after the target torque stops decreasing. During this time, the estimated torque temporarily becomes larger than the target torque, but this period is included in the period from when the target torque starts to decrease until the estimated torque stops decreasing. Therefore, if either the rate of change of the target torque or the rate of change of the estimated torque is negative, the ignition timing that is caused by the estimated torque temporarily becoming larger than the target torque is determined by limiting the retard of the ignition timing. Unnecessary timing delay can be reliably suppressed. Further, since the limitation on the retard of the ignition timing is performed only when it is permitted to limit the retard of the ignition timing, it is possible to prevent the adverse effects due to the limitation of the retard of the ignition timing.

  According to the second aspect of the invention, the request regarding the retard of the ignition timing issued from the host control device can be realized with certainty.

  According to the third aspect of the present invention, it is possible to suppress an increase in the temperature of the exhaust gas that accompanies the retard of the ignition timing, and consequently to suppress the deterioration of the exhaust purification catalyst due to overheating.

  According to the fourth aspect of the invention, the noise component included in the calculated value of the estimated torque is removed by the low-pass filter, so that the ignition timing retardation limit determination using the rate of change of the estimated torque is made accurate. Can do.

  According to the fifth aspect, it is possible to suppress an unnecessary retard of the ignition timing during a period in which the estimated torque is decreasing following the decrease in the target torque.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 3.

  FIG. 1 is a block diagram showing the overall configuration of an internal combustion engine control apparatus according to Embodiment 1 of the present invention. The control device of the present embodiment is applied to a spark ignition type internal combustion engine, and is configured as a control device that operates each of an electronic control throttle (hereinafter simply referred to as a throttle) that is an actuator of the spark ignition type internal combustion engine and an ignition device. Has been.

  The control device of the present embodiment is a so-called torque demand type control device that operates the throttle 10 and the ignition device 20 based on the target torque. Various torque requests are input to the control device from a powertrain manager (hereinafter referred to as PTM) (not shown) provided at the upper level of the control system. The torque request includes torque requests from various vehicle control systems in addition to torque requests from the driver. The target torque setting unit 2 of the control device arbitrates these multiple torque requests to one value and sets it as the target torque. The arbitration here is an operation of obtaining one numerical value from a plurality of numerical values in accordance with a predetermined calculation rule. Calculation rules include, for example, maximum value selection, minimum value selection, averaging, or superposition. The plurality of calculation rules may be appropriately combined.

  First, the control of the throttle 10 based on the target torque will be described. The target torque set by the target torque setting unit 2 is supplied to the target KL setting unit 4. The target KL setting unit 4 converts the target torque into an air amount (KL) using the KL map. Note that the air amount referred to here is the in-cylinder intake air amount per cycle, and may be replaced with a non-dimensional filling efficiency. The KL map is a multi-dimensional map with a plurality of parameters including torque as axes, and various operating conditions that affect the relationship between torque and air amount, such as ignition timing, engine speed, A / F, valve timing, and the like. Can be set as a parameter. Values obtained from the current operating state information are input to these parameters. However, the ignition timing is set to the optimal ignition timing (here, the more retarded ignition timing of the MBT and the trace knock ignition timing). The target KL setting unit 4 sets the air amount converted from the target torque as the target air amount (target KL), and outputs it to the throttle opening setting unit 6.

  The throttle opening setting unit 6 converts the target air amount into the throttle opening using an inverse model of the intake system air model. The air model is a physical model of the intake system, and the response of the air amount to the operation of the throttle 10 is modeled based on fluid dynamics or the like. In the inverse air model, which is the inverse model, operating conditions that affect the relationship between the air amount and the throttle opening, such as valve timing and intake air temperature, can be set as parameters. Values obtained from the current operating state information are input to these parameters. The throttle opening setting unit 6 outputs the throttle opening converted from the target air amount to the delay control unit 8.

  The delay control unit 8 receives the set value of the throttle opening from the throttle opening setting unit 6, generates a command signal from the delayed value by a predetermined delay time, and outputs the command signal to the throttle 10. That is, in the delay control unit 8, a delay time is provided from the setting of the throttle opening to the output timing of the command signal to the throttle 10. By performing such delay control, it becomes possible to predict the future throttle opening by the delay time. The predicted future throttle opening can be reflected in a control parameter value related to the air-fuel ratio control of the internal combustion engine, such as the fuel injection amount.

  Next, control of the ignition device 20 will be described. The signal used for ignition timing control in the control device of the present embodiment is torque efficiency. Torque efficiency is defined as the ratio of the target torque to the estimated torque of the internal combustion engine. The estimated torque used for calculating the torque efficiency is calculated based on the actual throttle opening realized by the throttle 10 as described below. The actual opening of the throttle 10 can be measured by a throttle opening sensor. It can also be calculated from the amount of rotation of the motor that drives the throttle 10.

  In calculating the estimated torque, first, the estimated KL calculating unit 12 calculates an air amount (estimated KL) that is estimated to be realized at the current throttle opening. The forward model of the aforementioned air model is used for calculating the estimated air amount. In addition, the air flow rate of the intake pipe measured by the air flow sensor is also used as correction data for the calculation using the air model.

  The estimated air amount calculated by the estimated KL calculating unit 12 is then converted into an estimated torque by the estimated torque calculating unit 14. The estimated torque calculation unit 14 converts the estimated air amount into torque using a torque map. The torque map is the reverse of the input and output of the KL map described above, with various operating conditions that affect the relationship between torque and air volume, such as ignition timing, engine speed, A / F, and valve timing, as parameters. Can be set. Values obtained from the current operating state information are input to these parameters, but the ignition timing is the optimum ignition timing. The estimated torque calculation unit 12 calculates the torque converted from the estimated air amount as the estimated torque at the optimal ignition timing.

  The torque efficiency is calculated by the torque efficiency calculator 16. The target torque is input from the target torque setting unit 2 to the torque efficiency calculation unit 16, and the estimated torque is input from the estimated torque calculation unit 14. The calculated torque efficiency is input to the ignition timing setting unit 18. The ignition timing setting unit 18 sets an ignition timing for making the actual torque of the internal combustion engine coincide with the target torque based on the torque efficiency, converts it into a command signal, and outputs it to the ignition device 20. The ignition device 20 performs an ignition operation in accordance with the input command signal.

  According to the configuration described above, priority is given to the adjustment of the intake air amount by the throttle 10 as a means for realizing the target torque. The ignition timing is adjusted with excellent torque response so as to compensate for the torque realization error caused by the delay in response of the intake air amount to the operation of the throttle 10. As a result, even when the target torque changes, the actual torque of the internal combustion engine can be changed so as to follow the change.

  Incidentally, there is a time lag, that is, a phase lag due to delay control or various response delays between the estimated torque and the target torque. For this reason, when the target torque changes in a decreasing direction, a period during which the estimated torque is larger than the target torque occurs temporarily, and the ignition timing is retarded so that the actual torque of the internal combustion engine approaches the target torque. Is done. Although the target torque can be realized with high accuracy by retarding the ignition timing, the fuel efficiency is deteriorated due to the decrease in efficiency.

  Therefore, the control device of the present embodiment includes a function for limiting the retard of the ignition timing in the ignition timing setting unit 18 when a predetermined operating condition is satisfied. The predetermined operating condition is an operating condition that allows the retard of the ignition timing to be limited, and includes, for example, that high torque accuracy is not required for the internal combustion engine. Hereinafter, a detailed configuration and function of the ignition timing setting unit 18 which is a main part for the control device of the present embodiment will be described.

  FIG. 2 is a block diagram showing a detailed configuration of the ignition timing setting unit 18 according to the present embodiment. The ignition timing setting unit 18 includes a retard amount calculation unit 32 that calculates the retard amount of the ignition timing from the torque efficiency. The retardation amount calculation unit 32 converts the torque efficiency into a retardation amount using the map. This map is a multi-dimensional map with a plurality of parameters including torque efficiency as axes, and various operating conditions that affect the setting of ignition timing, such as target torque, A / F, engine speed, valve timing, etc. Can be set as According to this map, when the torque efficiency is 1, which is the maximum efficiency, the retardation amount is set to zero, and as the torque efficiency is smaller than 1, the retardation amount is set to a larger value.

  The retardation amount calculated by the retardation amount calculation unit 32 is input to the retardation amount switching unit 46. The retard amount switching unit 46 can switch the output retard amount between the value calculated by the retard amount calculating unit 32 and zero. The retard amount output from the retard amount switching unit 46 is added to the optimum ignition timing in the ignition timing calculating unit 48. A value obtained by adding the retard amount to the optimum ignition timing is output from the ignition timing calculation unit 48 as the final ignition timing.

  The output switching by the retardation amount switching unit 46 is performed according to a switching signal input to the retardation amount switching unit 46. When the switching signal is OFF, the retard amount switching unit 46 outputs the value calculated by the retard amount calculating unit 32 to the ignition timing calculating unit 48. When the switching signal is turned on, the retardation amount switching unit 46 switches the retardation amount output to the ignition timing calculation unit 48 to zero until the switching signal is turned off again.

  The switching signal is output from the AND condition determination unit 44. The AND condition determination unit 44 determines whether the following two switching conditions A and B are satisfied / not satisfied. When one of the two switching conditions A and B is not satisfied, the switching signal output from the AND condition determination unit 44 is turned off. When the two switching conditions A and B are both satisfied, the switching signal output from the AND condition determination unit 44 is turned on.

  The switching condition A is that the estimated torque is temporarily larger than the target torque due to a phase shift between the estimated torque and the target torque. The switching condition B is that the current operating condition is an operating condition that is allowed to limit the retard of the ignition timing. By setting the retard amount to zero when the switching condition A is satisfied, it is possible to suppress an unnecessary retard of the ignition timing that occurs when the estimated torque temporarily becomes larger than the target torque. According to the switching condition B, the retard amount is switched to zero only when it is allowed to limit the retard of the ignition timing, so that it is possible to prevent the adverse effects due to the retard of the retard of the ignition timing. .

  The success or failure of the switching condition A is specifically determined from the change rate of the target torque and the change rate of the estimated torque. FIG. 3 is a graph showing changes over time in the estimated torque and the target torque. As shown in this graph, when there is a phase shift between the estimated torque and the target torque, the estimated torque temporarily becomes larger than the target torque in the process of decreasing the target torque. Then, for a while after the decrease in the target torque stops, the state where the estimated torque is larger than the target torque continues. As can be seen from FIG. 3, the period in which the estimated torque is larger than the target torque is included in the logical sum of the period in which the change rate of the target torque is negative and the period in which the change rate of the estimated torque is negative. . Therefore, if the retard amount is set to zero in the logical sum period, the unnecessary retard of the ignition timing can be surely limited. Therefore, the ignition timing setting unit 18 according to the present embodiment calculates the change rate of the target torque and the change rate of the estimated torque, respectively, and determines that one of them is negative as a condition for satisfying the switching condition A. To do.

  The ignition timing setting unit 18 determines whether or not the switching condition A is satisfied, so that the target torque change rate calculation unit 34, the magnitude determination unit 36, the estimated torque change rate calculation unit 38, the size determination unit 40, and the OR condition determination unit 42 are determined. It has. The target torque change rate calculation unit 34 calculates the change rate of the target torque. The magnitude determination unit 36 determines the magnitude relationship between the change rate of the target torque and zero. When the change rate of the target torque is smaller than zero, that is, when it is negative, the determination signal transmitted from the magnitude determination unit 36 to the OR condition determination unit 42 is turned on. The estimated torque change rate calculation unit 38 calculates the change rate of the estimated torque. The magnitude determination unit 40 determines the magnitude relationship between the rate of change of the estimated torque and zero. When the rate of change of the estimated torque is smaller than zero, that is, when it is negative, the determination signal transmitted from the magnitude determination unit 40 to the OR condition determination unit 42 is turned on. The OR condition determination unit 42 transmits a determination signal to be transmitted to the AND condition determination unit 44 when any of the input determination signals is on, that is, when either the target torque change rate or the estimated torque change rate is negative. turn on. The AND condition determination unit 44 determines that the switching condition A is satisfied if the determination signal from the OR condition determination unit 42 is on, and determines that the switching condition A is not satisfied if the determination signal is off. To do.

  In this embodiment, whether or not the switching condition B is satisfied is determined by the presence or absence of a retardation request signal from the PTM. PTM actively requests the internal combustion engine to retard the ignition timing when supplying high-temperature exhaust gas to the exhaust purification catalyst for warm air or when performing torque reserve control in preparation for acceleration, etc. To do. Since the retard request signal is a signal that is input from the PTM to the control device of the internal combustion engine in such a case, when the input of the retard request signal is on, the retard amount of the ignition timing cannot be switched to zero. It is not preferable. On the other hand, if the input of the retard angle request signal is off, there is no restriction from the PTM, so that it is allowed to make the retard amount of the ignition timing zero. The AND condition determination unit 44 determines that the switching condition B is satisfied if the retardation request signal from the PTM is OFF, and determines that the switching condition B is not satisfied if this determination signal is ON.

  According to the configuration and function of the ignition timing setting unit 18 described above, when either the target torque change rate or the estimated torque change rate is negative, the ignition timing retard amount is set to zero. Further, it is possible to reliably suppress an unnecessary retard of the ignition timing that occurs when the estimated torque is temporarily larger than the target torque. Further, since the restriction of the retard of the ignition timing is performed only when the retard request signal from the PTM is off, the request regarding the retard of the ignition timing issued from the PTM can be realized with certainty.

  The first embodiment of the present invention has been described above. The first embodiment embodies the first and second aspects of the present invention. Specifically, in the configuration shown in FIG. 1, the target torque setting unit 2 corresponds to the “target torque setting means” of the first invention. The electronically controlled throttle 10 corresponds to the “intake air amount adjusting valve” of the first invention, and the “intake air amount adjusting valve operating means” of the first invention by the target KL setting unit 4, the throttle opening degree setting unit 6 and the delay control unit 8. Is configured. The estimated KL calculator 12 and the estimated torque calculator 14 constitute the “estimated torque calculator” of the first invention. The torque efficiency calculation unit 16 and the ignition timing setting unit 18 constitute the “ignition timing retarding means” of the first invention. In the configuration shown in FIG. 2, the target torque change rate calculating unit 34 corresponds to the “target torque change rate calculating means” of the first invention, and the estimated torque change rate calculating unit 38 is the “estimated torque” of the first invention. It corresponds to “change rate calculation means”. The size determining unit 36, the size determining unit 40, the OR condition determining unit 42, the AND condition determining unit 44, and the retard amount switching unit 46 constitute the “retard angle limiting means” of the first and second inventions. .

Embodiment 2. FIG.
A second embodiment of the present invention will be described with reference to FIG.

  The control device for an internal combustion engine as the second embodiment of the present invention is different from the control device in the first embodiment in the configuration of the ignition timing setting unit 18. FIG. 4 is a block diagram showing a detailed configuration of the ignition timing setting unit 18 according to the present embodiment. In FIG. 4, elements common to the first embodiment are denoted by the same reference numerals. In the following, the description of the configuration common to the first embodiment is omitted or simplified, and the configuration different from the first embodiment is mainly described.

  The feature of the ignition timing setting unit 18 according to the present embodiment lies in the specific contents of the switching condition B in which establishment / non-establishment is determined by the AND condition determination unit 44. In the present embodiment, the switching condition B is the logical sum that the retardation request signal from the PTM is OFF and that the temperature of the exhaust purification catalyst exceeds a predetermined overheat determination temperature. The overheat determination temperature is related to the temperature at which the active point of the exhaust purification catalyst starts to deteriorate. By limiting the retard of the ignition timing when the catalyst temperature exceeds the overheat determination temperature, it is possible to suppress the exhaust gas temperature rise due to the retard of the ignition timing, and thereby suppress the deterioration of the exhaust purification catalyst due to overheating. it can.

  The ignition timing setting unit 18 according to the present embodiment includes a magnitude determination unit 50 and an OR condition determination unit 52 in order to determine whether or not the switching condition B is satisfied. The magnitude determination unit 50 determines the magnitude relationship between the catalyst temperature and the overheat determination temperature that is a threshold value. The catalyst temperature may be directly measured by attaching a temperature sensor to the exhaust purification catalyst, or may be calculated from the temperature of the exhaust gas. Alternatively, the catalyst temperature may be estimated by an exhaust gas model and a catalyst model. When the catalyst temperature is higher than the threshold value, the determination signal transmitted from the size determination unit 36 to the OR condition determination unit 52 is turned on. The OR condition determination unit 52 turns on the determination signal to be transmitted to the AND condition determination unit 44 when the retardation request signal from the PTM is off or the determination signal from the magnitude determination unit 36 is on. The AND condition determination unit 44 determines that the switching condition B is satisfied if the determination signal from the OR condition determination unit 52 is on, and determines that the switching condition B is not satisfied if the determination signal is off. To do.

  Embodiment 2 of the present invention embodies the first and third aspects of the present invention. Specifically, in the configuration shown in FIG. 4, the target torque change rate calculating unit 34 corresponds to the “target torque change rate calculating means” of the first invention, and the estimated torque change rate calculating unit 38 is “estimated” of the first invention. This corresponds to “torque change rate calculation means”. The size determination unit 36, the size determination unit 40, the OR condition determination unit 42, the size determination unit 50, the OR condition determination unit 52, the AND condition determination unit 44, and the retardation amount switching unit 46 of the first and third inventions. The “retarding angle limiting means” is configured. Note that other correspondence between the second embodiment and the present invention is common to the correspondence between the first embodiment and the present invention.

Others.
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the following modifications may be made.

  When the switching conditions A and B are satisfied, the retard amount calculated by the retard amount calculator 32 may be multiplied by a correction coefficient less than 1 instead of setting the retard amount of the ignition timing to zero. . That is, limiting the retard of the ignition timing is to make the retard amount used in the ignition timing calculation unit 48 smaller than the retard amount calculated by the retard amount calculation unit 32. One example is to make it zero. Instead of correcting the retard amount calculated by the retard amount calculating unit 32 to the decreasing side, the torque efficiency input to the retard amount calculating unit 32 may be corrected to the increasing side.

  Only that the temperature of the exhaust purification catalyst exceeds the overheat determination temperature may be determined as a condition for satisfying the switching condition B. In addition, other operating conditions that are allowed to limit the retard of the ignition timing may be added to the conditions for satisfying the switching condition B. Regarding the switching condition A, it may be determined that the switching condition A is satisfied only when the estimated torque change rate is negative.

  In the above-described embodiment, the estimated torque change rate calculating unit 38 may be provided with a low-pass filter to calculate the change rate of the signal obtained by passing the estimated torque through the low-pass filter. By doing so, the noise component included in the calculated value of the estimated torque can be removed, and the determination of the ignition timing retardation restriction using the rate of change of the estimated torque can be made accurate. The same applies to the calculation of the change rate of the target torque, and a low pass filter may be provided in the target torque change rate calculation unit 34 to calculate the change rate of the signal obtained by passing the target torque through the low pass filter. .

  In the above-described embodiment, the throttle is used as the intake air amount adjustment valve. However, an intake valve with a variable valve lift mechanism may be used as the intake actuator. Further, an intake valve with a variable valve mechanism may be combined with the throttle.

1 is a block diagram showing the overall configuration of a control device for an internal combustion engine as Embodiment 1 of the present invention. FIG. It is a block diagram which shows the detailed structure of the ignition timing setting part concerning Embodiment 1 of this invention. It is a figure for demonstrating the effect by the ignition timing setting part concerning Embodiment 1 of this invention. It is a block diagram which shows the detailed structure of the ignition timing setting part concerning Embodiment 2 of this invention. It is a figure for demonstrating the problem which arises by the time gap between a target torque and an estimated torque.

Explanation of symbols

2 Target torque setting unit 4 Target KL setting unit 6 Throttle opening setting unit 8 Delay control unit 10 Electronic control throttle 12 Estimated KL calculation unit 14 Estimated torque calculation unit 16 Torque efficiency calculation unit 18 Ignition timing setting unit 20 Ignition device 32 Delay angle Quantity calculation unit 34 Target torque change rate calculation unit 36 Size determination unit 38 Estimated torque change rate calculation unit 40 Size determination unit 42 OR condition determination unit 44 AND condition determination unit 46 Delay amount switching unit 48 Ignition timing calculation unit 50 Size determination unit 52 OR condition determination unit

Claims (5)

In a control device for an internal combustion engine capable of controlling the torque by the opening degree of the intake air amount adjustment valve and the ignition timing,
Target torque setting means for setting the target torque;
An intake air amount adjusting valve operating means for operating the intake air amount adjusting valve based on the target torque;
Estimated torque calculating means for calculating a torque obtained when the ignition timing is set to the optimal ignition timing (hereinafter, estimated torque) based on the actual opening of the intake air amount adjusting valve;
An ignition timing retarding means for retarding an ignition timing so that an actual torque of the internal combustion engine approaches the target torque when the estimated torque is larger than the target torque;
Target torque change rate calculating means for calculating a change rate of the target torque;
Estimated torque change rate estimating means for calculating a change rate of the estimated torque;
The ignition timing is satisfied when a predetermined operating condition that allows the retard of the ignition timing to be retarded is satisfied and either the rate of change of the target torque or the rate of change of the estimated torque is negative. Retardation limiting means for limiting the retardation of the ignition timing by the retardation means;
A control device for an internal combustion engine, comprising:   2. The control of an internal combustion engine according to claim 1, wherein the predetermined operating condition includes that a request for retarding the ignition timing is not issued from a host control device that controls the entire drive system of the vehicle. apparatus.   The internal combustion engine according to claim 1 or 2, wherein the predetermined operating condition includes that a temperature of an exhaust purification catalyst disposed in an exhaust passage of the internal combustion engine exceeds a predetermined overheat determination temperature. Engine control device.   The control apparatus for an internal combustion engine according to any one of claims 1 to 3, wherein the estimated torque change rate calculation means calculates a change rate of a signal obtained by passing the estimated torque through a low-pass filter. . In a control device for an internal combustion engine capable of controlling the torque by the opening degree of the intake air amount adjustment valve and the ignition timing,
Target torque setting means for setting the target torque;
An intake air amount adjusting valve operating means for operating the intake air amount adjusting valve based on the target torque;
Estimated torque calculating means for calculating a torque obtained when the ignition timing is set to the optimal ignition timing (hereinafter, estimated torque) based on the actual opening of the intake air amount adjusting valve;
An ignition timing retarding means for retarding an ignition timing so that an actual torque of the internal combustion engine approaches the target torque when the estimated torque is larger than the target torque;
Estimated torque change rate estimating means for calculating a change rate of the estimated torque;
When predetermined operating conditions permitting the restriction of the ignition timing retardation are satisfied and the rate of change of the estimated torque is negative, the ignition timing retardation by the ignition timing retardation means is reduced. A retard angle limiting means for limiting,
A control device for an internal combustion engine, comprising:

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