JP2003278591A - Torque control device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve torque controllability without increase in the number of maps of ignition timing efficiency curves in torque compensation caused by a change in combustion form of an internal combustion engine. <P>SOLUTION: As for the ignition timing efficiency to a lag amount from MBT (Minimum Spark Advance for Best Torque), a curvature of an ignition timing efficiency curve corresponding to a change of an operating condition is corrected by a control unit 10 according to the ignition lag time due to heat generation rate characteristic at the combustion time of an internal combustion engine and the subsequent main combustion time. Thus, the torque controllability at the change of the operating condition is improved by correction for the curvature of the ignition timing efficiency curve in the simple constitution. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque control device for an internal combustion engine, which controls torque in consideration of ignition timing efficiency with respect to a required torque of the internal combustion engine by a driver.

[0002]

2. Description of the Related Art Conventionally, as a prior art document relating to a torque control device for an internal combustion engine, Japanese Patent Publication No. 10-503259 is available.
The one disclosed in the publication is known. In this prior art document, the MBT in a predetermined operating condition of the internal combustion engine
A technique for realizing torque compensation by an internal combustion engine using a quadratic curve (parabolic relationship) representing ignition timing efficiency as torque efficiency associated with a change in the retard angle amount from is shown.

[0003]

In recent years, a direct injection engine for directly injecting fuel into a cylinder of an internal combustion engine has been developed and put into practical use for the purpose of improving fuel efficiency and emission. In order to achieve the same purpose, swirl and external EGR
Control systems such as (Exhaust Gas Recirculation), variable valve timing for intake and exhaust valves, and variable valve lift have been introduced.

In such an internal combustion engine, for example,
Fig. 14 (a) shows the effect of A / F (air-fuel ratio), Fig. 14 (b)
The swirl effect and the external EGR effect are shown in FIG. 14C, respectively. As shown in FIG. 14C, the torque accompanying the change in the retard angle amount from the MBT depending on the A / F, the swirl, and the external EGR that change the combustion mode of the internal combustion engine. It can be seen that the ignition timing efficiency as efficiency changes.

That is, under the influence of the A / F shown in FIG. 14A, when the A / F is 12 (rich), the MBT is larger than when the A / F is 14.7 (theoretical air-fuel ratio). It can be seen that the drop in the ignition timing efficiency with respect to the retard angle amount is small, and conversely, when A / F = 16 (lean), the drop in the ignition timing efficiency with respect to the retard amount from the MBT is large. Further, as for the influence of the swirl shown in FIG. 14B, when the swirl is weak, the decrease in the ignition timing efficiency with respect to the retard amount from the MBT is small, and when the swirl is strong, the decrease in the ignition timing efficiency with respect to the retard amount from the MBT is decreased. You can see that it is very complicated. As for the influence of the external EGR shown in FIG. 14C, when EGR = 0 [step] and there is no external EGR, the ignition timing efficiency greatly decreases with respect to the retard amount from the MBT, and when the external EGR increases, the external EGR increases. It can be seen that the decrease in the ignition timing efficiency with respect to the retard amount of is small.

By the way, the above-mentioned special table 10-50325.
No. 9 discloses that the torque is quickly compensated with the change of the combustion mode of the internal combustion engine, but the torque controllability due to the change of the ignition timing efficiency is not described, and one ignition timing is set under all operating conditions. When trying to compensate the torque using the efficiency curve, there is a problem that the required torque cannot be realized and the torque controllability deteriorates. On the contrary, if an ignition timing efficiency curve corresponding to all operating conditions is to be provided, there is a problem that the number of maps increases, the number of matching man-hours increases, and the calculation load in the control unit increases.

Therefore, the present invention has been made in order to solve such a problem, and can improve the torque controllability without increasing the number of maps of the ignition timing efficiency curve at the time of torque compensation accompanying the change of the combustion mode of the internal combustion engine. An object of the present invention is to provide a torque control device for an internal combustion engine.

[0008]

According to the torque control device for an internal combustion engine of claim 1, the required shaft torque required for the drive shaft of the internal combustion engine is based on the accelerator operation of the driver calculated by the required shaft torque calculation means. Is corrected by the ignition timing efficiency correction means with the torque efficiency corresponding to the retard amount based on the retard amount from the MBT under the operating condition of the internal combustion engine, and the internal combustion engine is controlled by the control means based on the corrected required shaft torque. At this time, the ignition delay period calculation means calculates the ignition delay period from the ignition timing to the time when combustion is started in the heat release rate characteristics during combustion of the internal combustion engine. The main combustion period until the generation rate decreases is calculated by the main combustion period calculation means, and is used by the ignition timing efficiency correction means based on the ignition delay period and the main combustion period. Torque efficiency corresponding to the angular amount is corrected by the torque efficiency correcting means. That is, the torque efficiency corresponding to the retard amount is corrected by the ignition delay period and the main combustion period corresponding to the change in the operating condition of the internal combustion engine. With such a simple configuration, the torque control is performed based on the corrected torque efficiency corresponding to the change in the operating condition of the internal combustion engine.
The effect that the torque controllability is improved is obtained.

According to another aspect of the present invention, there is provided a torque control device for an internal combustion engine, wherein the required torque shown in the required torque calculation means is calculated by the required torque calculated by the required torque calculation means by the driver and the mechanical loss torque of the internal combustion engine. Is calculated and the required indicated torque is corrected by the ignition timing efficiency correction means with the torque efficiency corresponding to the retard angle amount. Thereby, the required indicated torque calculated based on the required shaft torque and the mechanical loss torque is suitably corrected by the torque efficiency corresponding to the retard amount.

In the torque control device for an internal combustion engine according to claim 3, the ignition delay period or the main combustion period is set on the basis of the A / F, the swirl, the external EGR, etc., which change the combustion mode of the internal combustion engine. The curvature of the ignition timing efficiency curve corresponding to the change of is suitably corrected.

In the torque control device for an internal combustion engine according to a fourth aspect of the present invention, the ignition delay period is set based on the swirl that changes the air flow in the combustion chamber of the internal combustion engine, so that the curvature of the ignition timing efficiency curve corresponding to the change in the operating condition. Is preferably corrected.

According to another aspect of the present invention, there is provided a torque control device for an internal combustion engine, wherein the main combustion period changes the combustion speed of the internal combustion engine by A /
By setting based on F and the external EGR, the curvature of the ignition timing efficiency curve corresponding to the change in the operating condition is suitably corrected.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on Examples.

FIG. 1 is a block diagram showing a schematic configuration of a torque control device for an internal combustion engine according to an embodiment of the present invention.

In FIG. 1, reference numeral 10 is a control unit for an internal combustion engine. The control unit 10 is connected to an accelerator opening sensor (not shown) via an input line 31 and is operated by a driver (driver) to operate an accelerator pedal. The accelerator opening Ap from the accelerator opening sensor corresponding to the amount is input. Further, the control unit 10 is connected to various sensors (not shown) via input lines 32, 33, 34, 35, 36, ...
[Rpm], intake air amount GN [g / rev], A / F (air-fuel ratio), swirl, external EGR, etc. are input. The control unit 10 is connected via an output line 39 to a throttle mechanism 40 that can open and close the throttle valve of the internal combustion engine with an actuator.

The control unit 10 includes a CPU as a central processing unit for executing various well-known arithmetic processes, a ROM storing control programs and control maps, a RAM storing various data, a B / U (backup) RAM, It is configured as a logical operation circuit including an input circuit for inputting various sensor signals and the like from the input lines 31 to 36, ..., An output circuit for outputting control signals and the like to the output line 39, and a bus line connecting them. There is.

Next, each block of FIG. 1 showing individual control programs and program steps by the control unit 10 used in the torque control apparatus for an internal combustion engine according to one example of the embodiment of the present invention will be described in detail. explain.

In each block shown in FIG. 1, the required axial torque calculation processing 11 is a calculation processing for converting the torque requested by the driver into the axial torque to be generated by the crankshaft of the internal combustion engine based on the accelerator pedal depression amount by the driver. Is. In the required shaft torque calculation process 11, the accelerator opening Ap from an accelerator opening sensor (not shown) corresponding to the accelerator pedal depression amount of the driver is read. Further, the engine loss torque calculation process is a calculation process for calculating mechanical loss torque in the internal combustion engine. The required air amount calculation process is a calculation process for calculating the required air amount for obtaining the shaft torque required in the current operating state. Therefore, in the required air amount calculation process 13, the engine loss torque calculated in the engine loss torque calculation process 12 is added to the required shaft torque calculated in the required shaft torque calculation process 11, and the corrected ignition timing efficiency described later is used. The divided value and the engine speed NE are read.

On the other hand, the MBT calculation process 15 is a calculation process for calculating the optimum ignition timing in a predetermined operating state of the internal combustion engine. Further, the main combustion period calculation process of the main combustion period / actual retardation amount calculation process 17 under the current operating conditions corrects the change in the ignition timing efficiency caused by the change in the main combustion period. It is a calculation process for calculating the rate of change of the main combustion period with respect to the state.

The MBT calculation process 15 and the main combustion period / actual retard angle calculation process 17 under the current operating conditions include
Current engine speed NE, intake air amount GN, A / F for changing combustion mode, swirl, external E from various sensors
GR is read. Further, the ignition timing efficiency calculation process 16 under the standard operating condition corrects the torque change rate with respect to the retard angle amount from the MBT in the predetermined operating state.
In the calculation process, the indicated torque at T is set to "1" and the rate of change of the indicated torque with respect to the retard amount is calculated. In the ignition timing efficiency calculation processing 16 under the reference operating condition, MB
The control unit 1 from the MBT calculated in the T arithmetic processing 15
The value obtained by subtracting the actual ignition timing obtained within 0 is read. Main combustion period change rate calculation processing for standard operating conditions 1
Reference numeral 8 is a calculation process for calculating the rate of change of the main combustion period in the current operating state with respect to the standard operating condition. Then, the main combustion period change rate calculation process 18 for the reference operating condition is read with the main combustion period α1 calculated in the main combustion period / actual retardation amount calculation process 17 under the current operating condition. The actual retardation amount change rate calculation process 20 for the reference operating condition is a calculation process for calculating the change rate of the actual retardation amount under the current operating condition for the reference operating condition. Further, the actual retardation amount change rate calculation process 20 for the reference operating condition is read with the actual retardation amount α2 calculated in the main combustion period / actual retardation amount computing process 17 under the current operating condition.

Further, in the correction amount (correction coefficient) calculation process 19, the main combustion period change rate calculation process 1 for the standard operating condition is performed.
The main combustion period change rate β1 calculated in 8 is read. Further, the correction amount (correction coefficient) calculation process 21 reads the actual retardation amount α2 calculated in the actual retardation amount calculation process 20 for the reference operating condition. The corrected ignition timing efficiency calculation process 22 is a calculation process for calculating the corrected ignition timing efficiency described above. The corrected ignition timing efficiency calculation processing 22 includes the ignition timing efficiency calculated in the ignition timing efficiency calculation processing 16 under the standard operating condition, the correction amount (correction coefficient) k1 calculated in the correction amount (correction coefficient) calculation processing 19, and Correction amount (correction coefficient) calculation process 2
The correction amount (correction coefficient) k2 calculated in 1 is read.

The required throttle opening degree calculation process 14 is a calculation process for calculating the required throttle opening amount required for the throttle mechanism 40 to obtain the required air amount. In this way, the required throttle opening degree calculation process 14 takes into account the corrected ignition timing efficiency calculated in the corrected ignition timing efficiency calculation process 22, and the required air amount and the engine speed calculated in the required air amount calculation process 13 are taken into consideration. The speed NE is read. Then, the required throttle opening calculated in the required throttle opening calculation processing 14 is output to the throttle mechanism 40, and the throttle mechanism 40 is adjusted according to the required throttle opening.

Here, the inventor has clarified that the "ignition delay period" and "main combustion period" in the heat release rate waveform at the time of combustion change depending on the combustion mode as a factor that changes the ignition timing efficiency. did. In the heat release rate waveform shown in FIG. 2, the ignition delay period decreases from the ignition timing of the internal combustion engine to the time point when combustion is started, and the main combustion period decreases after the ignition delay period and before the completion of combustion. Up to the point in time, and the combustion lowering period is defined as after the main combustion period until the point at which the combustion is completed.

This phenomenon will be described in detail with reference to FIGS. 3 and 4 regarding A / F and swirl for changing the combustion mode. 3 and 4 indicate a TDC (Top Dead Cen) in piston movement of the internal combustion engine.
ter: compression top dead center).

First, as shown in FIG. 3 (a), MBT and 20 [° CA (Crank Angle: crank angle)] from MBT
Focusing on the main combustion period at the time of retard, A / F is lean (A
/ F = 16), from MBT to 20 [° C
A] At the time of retardation, the main combustion period tends to be long (see the difference in the length of the white arrow). And from the MBT 20
At the time of retardation of [° CA], as shown in FIG. 3B, the main combustion period [° CA] changes from A / F = 12 (rich) to A / F.
It turns out that it becomes longer as = 16 (lean). When the main combustion period becomes longer, the amount of afterburning in the expansion stroke increases and the effective torque amount decreases. That is, A /
The leaner F is, the larger the torque decrease rate from the MBT to the retard angle is. Therefore, as shown in FIG.
The leaner the A / F, the smaller the ignition timing efficiency (torque efficiency) on the side where the amount of retardation from the MBT is large may be corrected.

Further, as shown in FIG. 4 (a), focusing on the ignition delay period at the time of 20 [° CA] retardation from MBT and MBT, 2 MBT from MBT under the condition without swirl.
The ignition delay period tends to be shortened when 0 ° CA is retarded (see the difference in the length of the white arrow). And MBT
4 to 20 [° CA], as shown in FIG. 4 (b), the ignition delay period at the time of retard becomes shorter in the condition without swirl than in the condition with swirl, and the actual amount of retard [° CA]
It turns out that is shortened. When the ignition delay period is shortened, the actual ignition timing (main combustion period start timing) is advanced, and the actual retardation amount is shortened. That is, with respect to the retard amount from the same MBT, the torque reduction rate is smaller when the swirl is not provided than when the swirl is provided. Therefore, as shown in FIG. 4C, the stronger the swirl, the smaller the ignition timing efficiency (torque efficiency) on the side where the amount of retardation from the MBT is large may be corrected.

Next, based on the flowchart of FIG. 5, which shows the processing procedure of the required throttle opening degree calculation in the control unit 10 used in the torque control device for the internal combustion engine according to one example of the embodiment of the present invention, 6 to 12
Will be described with reference to. Here, FIGS. 6 to 12 are maps for calculating various control amounts in FIG. The required throttle opening calculation routine is repeatedly executed by the control unit 10 every predetermined time.

In FIG. 5, first, step S101.
Then, as the current operating condition, the engine speed NE [rp
m], intake air amount GN [g / rev], A / F (air-fuel ratio), swirl, external EGR, etc. are read as parameters for changing the combustion mode. Next, the process proceeds to step S102, and the actual ignition timing is read. Next in step S103
Then, the engine loss torque is added to the required shaft torque from the driver to calculate the required indicated torque value. Next, the process proceeds to step S104, and the MBT is read based on a map (not shown) using the current operating conditions read in step S101 as parameters. Next in step S10
5, the retard amount [° CA] from the MBT obtained by subtracting the actual ignition timing read in step S102 from the MBT read in step S104 is calculated.

Next, the routine proceeds to step S106, where the ignition timing efficiency (torque efficiency) with respect to the retard amount (MBT-actual ignition timing) from the MBT calculated in step S105 under the standard operating condition is read (FIG. 6). Refer to the map shown in). The ignition timing efficiency may be calculated by the formula (ax ² +1). Where a is the curvature of the ignition timing efficiency curve, x
Is the retard amount from MBT (MBT-actual ignition timing).
Next, the routine proceeds to step S107, where the main combustion period α1 for the A / F under the current operating conditions is read (see the map shown in FIG. 7), and the actual retardation amount α for the swirl is read.
2 is read (see the map shown in FIG. 8A). The actual retard amount is defined as the difference [° CA] between the end point of the ignition delay period in MBT and the end point of the ignition delay period in MBT-20 ° CA, as shown in FIG. 8 (b). .

Next, the process proceeds to step S108 and the A / F
The main combustion period change rate β1 with respect to the standard operation condition of is read (see the map shown in FIG. 9). Next in step S109
Then, the actual retardation angle change rate β2 with respect to the swirl reference operating condition is read (see the map shown in FIG. 10).
Next, the routine proceeds to step S110, where the main combustion period change rate β
The correction amount (correction coefficient) k1 for 1 is read (Fig. 1
See map 1). Next, the process proceeds to step S111, and the correction amount (correction coefficient) k for the actual retardation amount change rate β2.
2 is read (see the map shown in FIG. 12).

Next, in step S112, the ignition timing efficiency in the standard operating condition in step S106, the main combustion period α1 and the actual retardation amount α2 in step S107, and the main combustion period change rate β1 in step S108.
And the actual rate of change in the amount of retardation β2 in step S109,
The corrected ignition timing efficiency is calculated based on the correction amount (correction coefficient) k1 in step S110 and the correction amount (correction coefficient) k2 in step S111. Here, the corrected ignition timing efficiency is calculated by adding the correction amount or multiplying the correction coefficient to the ignition timing efficiency under the standard operating condition in step S106. The equation of ignition timing efficiency curve (ax ²
The curvature a in +1) may be multiplied by the correction coefficient.

Next, the routine proceeds to step S113, where the requested indicated torque value calculated at step S103 is
The corrected indicated required torque is calculated by dividing by the corrected ignition timing efficiency calculated in 112. Next step S1
14, the requested air amount is calculated based on the requested indicated torque calculated in step S113 and the engine rotation speed NE. Next, the process proceeds to step S115, and the required throttle opening is calculated based on the required air amount and the engine speed NE calculated in step S114. Next, in step S116, the requested throttle opening calculated in step S115 is output to the throttle mechanism 40,
This routine ends.

As described above, the ignition timing efficiency is corrected based on the ignition delay period and the main combustion period. Then, as shown in FIG.
Without the correction shown in (b), the ignition timing efficiency (torque efficiency) is large with an error of ± 14 [%] when the retard amount from the MBT is 25 [° CA], whereas in Fig. 13 (a). With the correction of the present embodiment shown, it is possible to suppress the error in ignition timing efficiency (torque efficiency) to ± 5% even if the retard amount from the MBT is 25 [° CA]. As a result, the ignition timing efficiency curve corresponding to changes in operating conditions is mapped (2
The following curve) does not have to be provided at all, and the curvature of the ignition timing efficiency curve is suitably corrected using the ignition delay period and the main combustion period, so that torque controllability can be improved with a simple configuration.

As described above, the torque control device for the internal combustion engine of this embodiment is achieved by the control unit 10 which calculates the required axial torque required for the drive shaft of the internal combustion engine (not shown) based on the accelerator operation of the driver. The required shaft torque calculating means and the control unit 10 for correcting the required shaft torque with the torque efficiency corresponding to the retard amount based on the retard amount from the MBT (optimal ignition timing) under a predetermined operating condition of the internal combustion engine. The ignition timing efficiency correction means to be achieved and the control means to be achieved by the control unit 10 for controlling the internal combustion engine based on the required shaft torque corrected by the ignition timing efficiency correction means are provided. Ignition delay period calculation means achieved by the control unit 10 for calculating the ignition delay period from the ignition timing to the timing when combustion is started in the heat release rate characteristic. The main combustion period calculation means achieved by the control unit 10 for calculating the main combustion period from the ignition delay period until the heat generation rate decreases before the completion of combustion, and the retard angle amount used by the ignition timing efficiency correction means. The torque efficiency correction means is provided in the control unit 10 for correcting the corresponding torque efficiency based on the ignition delay period and the main combustion period.

That is, the ignition timing efficiency (torque efficiency) with respect to the retard angle amount from the MBT under the predetermined operating condition of the internal combustion engine is corrected based on the ignition delay period and the main combustion period subsequent thereto. That is, the ignition timing efficiency is corrected by the ignition delay period and the main combustion period corresponding to the change in the operating condition of the internal combustion engine. With such a simple configuration, torque control is performed based on the corrected ignition timing efficiency based on the ignition timing efficiency curve whose curvature is corrected in response to changes in the operating conditions of the internal combustion engine, and therefore torque controllability can be improved.

Further, control for calculating the required indicated torque on the basis of the required axial torque by the driver calculated by the required axial torque calculating means achieved by the control unit 10 and the engine loss torque which is the mechanical loss torque of the internal combustion engine. The ignition timing efficiency correction means achieved by the control unit 10 is provided with a requested torque calculation means achieved by the unit 10, and the requested torque calculated by the requested torque calculation means is equivalent to the retard amount. It is corrected by the torque efficiency. Thus, the required indicated torque calculated based on the required shaft torque and the engine loss torque is suitably corrected by the torque efficiency corresponding to the retard angle amount as the ignition timing efficiency.

In the torque control system for an internal combustion engine of this embodiment, the ignition delay period or the main combustion period is set based on A / F, swirl, external EGR, etc. as parameters for changing the combustion mode of the internal combustion engine. It is a thing. Of these, the ignition delay period is set based on the swirl as a parameter that changes the air flow in the combustion chamber among the parameters that change the combustion mode of the internal combustion engine. Further, the main combustion period is set on the basis of the A / F and the external EGR as parameters that change the combustion speed among the parameters that change the combustion mode of the internal combustion engine.

That is, the ignition delay period or the main combustion period due to the heat release rate characteristic during combustion of the internal combustion engine is set based on the A / F, the swirl, the external EGR, etc., which change the combustion mode of the internal combustion engine. The ignition delay period is set based on the swirl that changes the air flow in the combustion chamber, and the main combustion period is set based on the A / F and the external EGR that change the combustion speed. By thus setting the ignition delay period or the main combustion period, it is possible to preferably correct the curvature of the ignition timing efficiency curve corresponding to the change in the operating condition.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a torque control device for an internal combustion engine according to an example of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an ignition delay period and a main combustion period in a heat release rate waveform used in a torque control device for an internal combustion engine according to an example of an embodiment of the present invention.

FIG. 3 is a diagram showing an ignition delay period by A / F as a parameter for changing the combustion mode as a factor for changing the ignition timing efficiency in the torque control device for the internal combustion engine according to one example of the embodiment of the present invention. FIG. 5 is an explanatory diagram showing changes in the main combustion period.

FIG. 4 is a diagram showing an ignition delay period due to a swirl as a parameter for changing a combustion mode as a factor for changing an ignition timing efficiency in a torque control device for an internal combustion engine according to an example of an embodiment of the present invention; It is explanatory drawing which shows the change of a combustion period.

FIG. 5 is a flowchart showing a processing procedure of a required throttle opening degree calculation in a control unit used in a torque control device for an internal combustion engine according to an example of an embodiment of the present invention.

FIG. 6 is a map for calculating the ignition timing efficiency in step S106 of FIG.

FIG. 7 is a map for calculating a main combustion period in step S107 of FIG.

FIG. 8 is a map for calculating an actual retard amount in step S107 of FIG.

9 is a map for calculating a main combustion period change rate in step S108 of FIG.

FIG. 10 is a map for calculating the actual retardation amount change rate in step S109 of FIG.

11 is a map for calculating a correction amount (correction coefficient) in step S110 of FIG.

FIG. 12 is a map for calculating a correction amount (correction coefficient) in step S111 of FIG.

FIG. 13 compares the relationship between the retard angle amount from the MBT and the ignition timing efficiency with no correction as an effect of correction with the torque control device for an internal combustion engine according to an example of the embodiment of the present invention. FIG.

FIG. 14 is a characteristic diagram showing that the relationship between the retard amount from a general MBT and the ignition timing efficiency is influenced by the parameter that changes the combustion mode.

[Explanation of symbols]

10 control unit

Claims (5)

[Claims] 1. A required shaft torque calculating means for calculating a required shaft torque required by a drive shaft of an internal combustion engine based on an accelerator operation of a driver, and an optimum ignition timing (MBT: Minimum Spark) under a predetermined operating condition of the internal combustion engine. Advance for
Best Torque) based on the retard amount from the ignition timing efficiency correction means for correcting the required shaft torque with a torque efficiency corresponding to the retard angle amount, and based on the required shaft torque corrected by the ignition timing efficiency correction means. In a torque control device for an internal combustion engine, which comprises a control means for controlling the internal combustion engine, ignition for calculating an ignition delay period from an ignition timing in a heat release rate characteristic during combustion of the internal combustion engine to a timing at which combustion is assumed to start. Delay period calculation means, main combustion period calculation means for calculating a main combustion period from the ignition delay period until the heat release rate decreases before combustion is completed, and the retard amount used by the ignition timing efficiency correction means Of the internal combustion engine, comprising: a torque efficiency correction means for correcting the torque efficiency corresponding to the above based on the ignition delay period and the main combustion period. Torque control device. 2. A requested indicated torque calculation means for calculating a requested indicated torque based on the requested axial torque calculated by the requested shaft torque calculating means and a mechanical loss torque of the internal combustion engine, the ignition timing efficiency The torque control device for an internal combustion engine according to claim 1, wherein the correction means corrects the requested indicated torque calculated by the requested indicated torque calculating means with a torque efficiency corresponding to a retard angle amount. 3. The torque of the internal combustion engine according to claim 1, wherein the ignition delay period or the main combustion period is set based on a parameter that changes a combustion mode of the internal combustion engine. Control device. 4. The torque of the internal combustion engine according to claim 3, wherein the ignition delay period is set based on a parameter that changes an air flow in the combustion chamber among parameters that change a combustion mode of the internal combustion engine. Control device. 5. The torque control of an internal combustion engine according to claim 3, wherein the main combustion period is set based on a parameter that changes a combustion speed among parameters that change a combustion mode of the internal combustion engine. apparatus.