JPH09287513A - Torque controller for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compatibly control the target air/fuel ratio and target torque of an engine by controlling an intake air quantity and a fuel supply quantity so as to obtain the target engine torque and the target air/fuel ratio which meet the operation state of the engine. SOLUTION: The operation quantity of an accelerator APS and an engine speed Ne are inputted into a computting section A for a standard target intake air quantity, and the section A computes a standard target intake air quantity tTP so as to make a target engine torque corresponding to an operation state attain a value equivalent to an intake air quantity. In addition, a target equivalent ratio computing section B computes a target equivalent ratio tDML according to the target air/fuel ratio corresponding to an operation state. A target intake air quantity computing section C computes a target intake air quantity tTP' by dividing the standard target intake air quantity tTP by a target equivalent ratio tDML. Next a target throttle valve opening computing section D computes a target throttle valve opening tTPS from the target intake air quantity tTP' and the engine speed Ne to control the opening of the throttle valve through a throttle valve controller 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine torque control device.

[0002]

2. Description of the Related Art A conventional engine torque control device is disclosed in, for example, Japanese Patent Application Laid-Open No. Sho 62-110536.

[0003]

However, in such a conventional engine torque control device, the target throttle valve opening is directly searched for from the target engine torque and the engine rotation speed. This is because a predetermined air-fuel ratio (for example, a stoichiometric air-fuel ratio) is set as a premise, and there is a problem that the air-fuel ratio cannot be directly applied to an engine in which the air-fuel ratio is variably controlled according to an operating state.

That is, as shown in FIG. 12, in order to change the air-fuel ratio while maintaining the same engine operating performance, that is, the engine rotation speed and the engine torque, both the throttle valve opening and the fuel supply amount are changed. It is necessary to change, for example, when the air-fuel ratio is lean, the required intake air amount increases and the required fuel supply amount decreases compared to when the air-fuel ratio is the theoretical air-fuel ratio. It wasn't possible.

The present invention has been made in view of such conventional problems, and an object thereof is to control the engine torque to the target value while maintaining the air-fuel ratio at the target value. It is another object of the present invention to enable a simple calculation for a change in the target air-fuel ratio or control the engine torque to a target value with a small amount of data.

[0006]

Therefore, in the invention according to claim 1, the intake air amount and the fuel supply amount are set so that the target engine torque and the target air-fuel ratio according to the operating state of the engine can be obtained. It is characterized by controlling. In the invention according to claim 2, the control of the intake air amount is performed by a throttle valve control device that controls the opening degree of a throttle valve installed in an intake system of an engine to a target value. It is characterized by being performed by controlling.

The invention according to claim 3 is, as shown in FIG. 1, supplied to the engine and a throttle valve control device for controlling the opening of the throttle valve interposed in the intake system of the engine to a target value. In a torque control device for an engine, which includes a fuel supply amount control device for controlling a fuel amount to a target value, an accelerator operation amount detection means for detecting an accelerator operation amount, and an engine rotation speed detection means for detecting an engine rotation speed. And an intake air amount detecting means for detecting an intake air amount to the engine, and a reference target intake air amount corresponding to the reference air-fuel ratio is calculated based on the detected accelerator operation amount and the detected engine rotation speed. The reference target intake air amount calculation means, and the target intake air amount is corrected based on the detected accelerator operation amount and the detected engine speed. A target intake air amount calculating means for calculating a target intake air amount corresponding to the fuel ratio; and a target throttle valve opening calculating means for calculating a target throttle valve opening based on the target intake air amount and the engine speed. And a fuel supply amount calculation means for calculating a fuel supply amount based on the intake air amount detected by the intake air amount detection means, the engine rotation speed, and the target air-fuel ratio. Controls the opening of the throttle valve so that the calculated target throttle valve opening is obtained, and the fuel supply amount control device controls the fuel supply amount so as to reach the calculated fuel supply amount. , The engine torque is controlled to a target value.

The invention according to claim 4 is, as shown in FIG. 2, provided with a throttle valve control device for controlling the opening of a throttle valve interposed in the intake system of the engine to a target value, and the engine. In a torque control device for an engine, which includes a fuel supply amount control device for controlling a fuel amount to a target value, an accelerator operation amount detection means for detecting an accelerator operation amount, and an engine rotation speed detection means for detecting an engine rotation speed. And an intake air amount detecting means for detecting an intake air amount to the engine, and a target engine torque is calculated based on the detected accelerator operation amount and the detected engine rotation speed or by a command from the outside. Based on the target engine torque calculating means and the calculated target engine torque and engine rotation speed, a reference target intake torque corresponding to the reference air-fuel ratio. Reference target intake air amount calculation means for calculating the air amount, target intake air amount calculation means for correcting the reference target intake air amount to calculate the target intake air amount corresponding to the target air-fuel ratio, and the target intake air amount And target engine speed based on the engine speed and the target throttle valve opening calculation means, based on the intake air amount detected by the intake air amount detection means, the engine speed and the target air-fuel ratio. And a fuel supply amount calculating means for calculating a fuel supply amount, and the throttle valve control device controls the opening of the throttle valve so as to reach the calculated target throttle valve opening. The fuel supply amount control device controls the fuel supply amount so as to be the calculated fuel supply amount, and controls the engine torque to a target value.

Further, the invention according to claim 5 is a target equivalent for calculating a target equivalent ratio corresponding to a reference air-fuel ratio / target air-fuel ratio, based on the detected accelerator operation amount and the detected engine speed. The target intake air amount calculation unit calculates the target intake air amount by dividing the reference target intake air amount by the target equivalence ratio, and the fuel supply amount calculation unit includes the ratio calculation unit. The fuel supply amount is calculated by multiplying the fuel supply amount corresponding to the reference air-fuel ratio calculated based on the intake air amount detected by the intake air amount detection means and the engine rotation speed by the target equivalence ratio. And

Further, in the invention according to claim 6, the target equivalent ratio calculating means calculates a second target equivalent ratio having a delayed phase, and the fuel supply amount calculating means is detected by the intake air amount detecting means. It is characterized in that the fuel supply amount is calculated by multiplying the fuel supply amount corresponding to the reference air-fuel ratio calculated on the basis of the intake air amount and the engine speed, which are calculated, by the second target equivalence ratio.

Further, the invention according to claim 7 is configured to include a fuel consumption rate correction coefficient calculation means for calculating a fuel consumption rate correction coefficient in accordance with the target equivalent ratio, and the target throttle valve opening degree calculation means is The target throttle valve opening is calculated based on a second target intake air amount obtained by multiplying the target intake air amount by the fuel consumption rate correction coefficient and the engine rotation speed.

The invention according to claim 8 is, as shown in FIG. 3, supplied to an engine and a throttle valve control device for controlling the opening of a throttle valve interposed in an intake system of the engine to a target value. In a torque control device for an engine, which includes a fuel supply amount control device for controlling a fuel amount to a target value, an accelerator operation amount detection means for detecting an accelerator operation amount, and an engine rotation speed detection means for detecting an engine rotation speed. And an intake air amount detecting means for detecting an intake air amount to the engine, and a target intake air amount corresponding to the target air-fuel ratio is calculated based on the detected accelerator operation amount and the detected engine rotation speed. Target intake air amount calculation means, target throttle valve opening calculation means for calculating a target throttle valve opening based on the target intake air amount and engine speed, And a fuel supply amount calculating means for calculating a fuel supply amount based on the intake air amount detected by the intake air amount detecting means, the engine rotation speed and the target air-fuel ratio. While controlling the opening of the throttle valve so as to be the calculated target throttle valve opening, the fuel supply amount control device controls the fuel supply amount so as to be the calculated fuel supply amount, It is characterized in that the engine torque is controlled to a target value.

The invention according to claim 9 is, as shown in FIG. 4, supplied to the engine and a throttle valve control device for controlling the opening of the throttle valve interposed in the intake system of the engine to a target value. In a torque control device for an engine, which includes a fuel supply amount control device for controlling a fuel amount to a target value, an accelerator operation amount detection means for detecting an accelerator operation amount, and an engine rotation speed detection means for detecting an engine rotation speed. And an intake air amount detecting means for detecting an intake air amount to the engine, and a target engine torque is calculated based on the detected accelerator operation amount and the detected engine rotation speed or by a command from the outside. Target engine torque calculating means, and a target intake air amount corresponding to a target air-fuel ratio based on the calculated target engine torque and engine speed. A target intake air amount calculation means for calculating an amount, a target throttle valve opening calculation means for calculating a target throttle valve opening based on the target intake air amount and an engine speed, and the intake air amount detection means. And a fuel supply amount calculating means for calculating a fuel supply amount based on the detected intake air amount, engine rotation speed and target air-fuel ratio, wherein the throttle valve control device calculates the target throttle. The throttle valve opening is controlled to the valve opening, and the fuel supply control device controls the fuel supply to the calculated fuel supply to set the engine torque to the target value. It is characterized by controlling.

According to a tenth aspect of the present invention, the accelerator operation amount detecting means for detecting the accelerator operation amount, the engine rotation speed detecting means for detecting the engine rotation speed, and the detected accelerator operation amount are detected. A target engine torque calculating means for calculating a target engine torque based on the engine rotation speed or an external command, and a target intake air amount is calculated based on the calculated target engine torque and engine rotation speed. Target intake air amount calculating means, target throttle valve opening calculating means for calculating a target throttle valve opening based on the target intake air amount and engine speed, and a throttle installed in the intake system of the engine. In a torque control device for an engine that controls the opening of a valve to the calculated target throttle valve opening, at least Reference is made according to one or more inputs including the accelerator operation amount, and when the accelerator operation amount changes by a unit amount or more, the target engine torque map is set so that the absolute value of the target engine torque change amount for the accelerator operation amount becomes the minimum unit amount or more. A target opening area map in which a target opening area of the intake air passage is set on the basis of an operating state determined by the target engine torque map, and the target throttle valve opening calculation means calculates the intake air passage from the target opening area map. It is characterized in that the target throttle valve opening is calculated in accordance with the target opening area of the intake air passage referred to.

Further, the invention according to claim 11 is characterized in that the target engine torque calculating means calculates the target engine torque by referring to the target engine torque map based on the accelerator operation amount and the engine rotation speed. And Further, the invention according to claim 12 is characterized in that the target engine torque calculating means calculates the target engine torque based on a target driving force of a vehicle in which an engine is mounted and a shift position of a transmission.

The invention according to claim 13 is the invention according to claim 4,
The torque control device for an engine according to any one of claims 10 to 12 that satisfies any one of 5, 6, 7, and 9.

[0017]

According to the first aspect of the present invention, it is possible to obtain the required engine torque and ensure good driving performance while satisfying the exhaust gas purification performance while maintaining the target air-fuel ratio. According to the second aspect of the present invention, it is possible to perform the control that satisfies the target engine torque while maintaining the target air-fuel ratio with high responsiveness and high accuracy via the throttle valve control device.

Further, according to the third aspect of the invention, when setting the intake air amount and the fuel supply amount according to the engine operating condition so as to obtain the target engine torque, first, the reference air-fuel ratio is dealt with. This is a configuration in which the reference target intake air amount is calculated and then corrected by the target air-fuel ratio to calculate the final target intake air amount.

Here, since the reference target intake air amount is determined by the target engine torque and the engine rotation speed with respect to a constant reference air-fuel ratio, the change width (dynamic range) of data is small and the data required for calculation is small. The amount can be minimized and the reference target intake air amount can be corrected by a simple calculation. Here, since the reference target intake air amount is uniquely determined so that the target engine torque can be obtained with respect to the reference air-fuel ratio, when the target intake air amount is directly calculated from the target engine torque and the target air-fuel ratio. By comparison, the target intake air amount can be obtained with a data amount that is as small as possible.

According to the fourth aspect of the invention, first, the target engine torque is calculated based on the accelerator operation amount and the engine rotation speed, and then the reference intake air amount is calculated from the target engine torque and the engine rotation speed. This is different from the configuration of the invention of claim 3 in which the reference intake air amount corresponding to the target engine torque determined by the accelerator operation amount and the engine rotation speed is directly calculated. Since the other configurations are the same, the same effect as the effect of the invention of claim 3 is obtained.

According to the fifth aspect of the present invention, the value of reference air-fuel ratio / target air-fuel ratio is set in accordance with the target air-fuel ratio determined from the operating state based on the accelerator operation amount and the engine speed. It is possible to obtain the target intake air amount corresponding to the target air-fuel ratio by a simple calculation of the target equivalence ratio and dividing the reference target intake air amount by the target equivalence ratio.

Regarding the fuel supply amount, the fuel supply amount corresponding to the target air-fuel ratio can be obtained by a simple calculation by multiplying the actual intake air amount by the target equivalence ratio. According to the invention of claim 6, when the target air-fuel ratio changes, there is a delay in the change in the intake air amount due to the change in the target throttle valve opening, and when the target equivalent ratio is used as it is, the delay occurs. The engine torque deviates from the target value during the transient that is occurring.

Therefore, a second target equivalence ratio in which the phase of the target equivalence ratio is delayed corresponding to the delay of the target intake air amount is calculated, and the second target equivalence ratio is used to calculate the engine torque even in the transient state. Can be maintained close to the target value. Further, according to the invention of claim 7, the calculation using only the target equivalence ratio to obtain the target intake air amount from the reference target intake air amount is simple, but, for example, when the air-fuel ratio is made lean, Since it is not taken into consideration that the fuel supply amount can be reduced by improving the fuel consumption, it is set to a large amount, which causes a slight increase in engine torque. The engine torque increase can be adjusted by an accelerator operation, but the target intake air amount is corrected by using a fuel consumption rate correction coefficient,
By calculating the target intake air amount and calculating the target throttle valve opening based on the second target intake air amount,
Engine torque fluctuations are small and fuel consumption can be reduced as much as possible.

Further, according to the invention of claim 8, the target engine torque and the target air-fuel ratio are simultaneously determined based on the accelerator operation amount and the engine rotation speed, so the target air-fuel ratio is taken into consideration. The intake air amount can be directly calculated, the number of calculations can be reduced, and highly accurate calculation can be performed in consideration of all factors corresponding to each operating state.

Further, according to the invention of claim 9, the target air-fuel ratio is simultaneously determined on the basis of the target engine torque and the engine speed obtained from the accelerator operation amount and the engine speed. Similar to the invention described above, the target intake air amount can be directly calculated in consideration of the target air-fuel ratio, the number of calculations can be reduced, and highly accurate calculation considering all elements corresponding to each operating state. It can be performed.

According to the tenth aspect of the invention, the target engine torque map is set so that the target engine torque monotonically increases with a gradient of a certain value or more as the accelerator operation amount increases. The accuracy of the calculation of the target opening area of the intake air passage set based on the operating state determined by the is ensured, the accuracy of the throttle valve opening control is improved, and the throttle valve is reliably opened to the full operating range by the accelerator operation. The maximum torque can be secured.

According to the eleventh aspect of the present invention, the target engine torque referred to from the target engine torque map is used as it is, and the operating state determined by the target engine torque, specifically, the target intake air amount is used. The target opening area of the intake air passage is referred to from the target opening area map. Further, according to the invention of claim 12, from the driving force required based on the running state of the vehicle and the gear shift position of the transmission, a target engine torque that is more practical is obtained, and is determined by the target engine torque. The target opening area of the intake air passage is referred to from the target opening area map based on the operating state, specifically, the target intake air amount.

According to a thirteenth aspect of the present invention, in each of the fourth, fifth, sixth, seventh and ninth aspects of the present invention, the throttle valve opening control accuracy is improved, and the throttle valve is controlled by an accelerator operation. Can be reliably moved until the movable range is fully opened, and the fuel supply amount and the air-fuel ratio can be appropriately controlled while ensuring the maximum torque.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 5 shows a system configuration of one embodiment of the present invention (common to each control embodiment described later). Accelerator opening sensor 1 as accelerator operation amount detection means
Detects the amount of depression of the accelerator pedal depressed by the driver as the engine load (engine torque) desired by the driver.

The crank angle sensor 2 as an engine speed detecting means generates a position signal for each unit crank angle and a reference signal for each cylinder stroke phase difference, and measures the number of generated position signals per unit time. Due to
Or by measuring the reference signal generation period,
The engine speed can be detected. Air flow meter 3
Detects the intake air amount into the engine 4 (intake air amount per unit time = intake air flow rate).

The water temperature sensor 5 detects the cooling water temperature of the engine. The engine 4 is provided with a fuel injection valve 6 that is driven by a fuel injection signal to inject and supply fuel, and a spark plug 7 that is mounted in a combustion chamber and ignites.
A throttle valve 9 is provided in the intake passage 8 and a throttle valve control device 10 capable of electronically controlling the opening of the throttle valve 9 is provided.

Detection signals from the various sensors are input to the control unit 11, which controls the throttle valve control device 10 according to the operating state detected based on the signals from the sensors. Via the throttle valve 9, the fuel injection valve 6 is driven to control the fuel injection amount (fuel supply amount), the ignition timing is set, and the ignition plug 7 is ignited at the ignition timing. Take control.

FIG. 6 shows a functional configuration of the first embodiment according to the invention of claim 3. The accelerator operation amount APS and the engine rotation speed Ne are input to the reference target intake air amount calculation unit A which constitutes the reference target intake air amount calculation means, and the target engine torque corresponding to the operating state determined by the input values is input. Is the reference target intake air amount tTP as a value corresponding to the intake air amount obtained with the theoretical air-fuel ratio as the reference air-fuel ratio.
Is calculated. Specifically, the data of the reference target intake air amount tTP obtained experimentally in advance is used as the accelerator operation amount APS.
And the engine rotation speed Ne may be stored in a map and used as a parameter, and the map may be searched. The reference target intake air amount tTP is detected by the air flow meter 3 in addition to the basic fuel injection amount (pulse width) corresponding to the intake air amount for each intake stroke, as well as the intake air amount itself for each intake stroke. Any of the intake air amounts per unit time may be used.

The accelerator operation amount APS and the engine rotation speed Ne are input to a target equivalent ratio calculating unit B which constitutes a target equivalent ratio calculating means, and the target equivalent ratio is calculated according to the target air-fuel ratio corresponding to the operating condition. tDML is calculated. This target equivalence ratio tDML can also be calculated by searching the map. The target equivalent ratio tDML is basically calculated as reference air-fuel ratio (theoretical air-fuel ratio) / target air-fuel ratio, but this value may be corrected by the cooling water temperature Tw.

In the target intake air amount calculating section C as the target intake air amount calculating means, the reference target intake air amount tTP is set.
Is divided by the target equivalent ratio tDML to calculate a target intake air amount tTP ′ corresponding to the target air-fuel ratio. Here, the target intake air amount tTP 'corresponding to the target air-fuel ratio is the intake air amount determined so that the target engine torque can be obtained at the target air-fuel ratio.

The target intake air amount tTP 'and the engine speed Ne are input to a target throttle valve opening calculation unit D as a target throttle valve opening calculation means, and the target throttle valve opening tTPS is calculated. . The target throttle valve opening tTPS is a throttle opening such that a target intake air amount tTP 'can be obtained. The signal of the target throttle valve opening tTPS is input to the throttle valve control device 10, which causes the throttle valve control device 10 to move the throttle valve 8 to the target throttle valve opening tTPS.
Drive to become.

Next, the fuel supply amount will be described. The basic fuel supply amount calculating section E1 constituting the fuel supply amount calculating means.
And the correction calculation unit E2 calculates the fuel supply amount.
The intake air amount Q per unit time detected by the air flow meter 3 and the engine rotation speed Ne are input to the basic fuel supply amount calculation unit E1, and thereby the theoretical air-fuel ratio is obtained.
A basic fuel injection pulse width TP corresponding to the intake air amount per intake stroke at the time of (reference air-fuel ratio) is calculated.

The correction calculator E2 calculates the effective fuel injection pulse width TE by multiplying the basic fuel injection pulse width TP by the target equivalent ratio tDML, and calculates the effective fuel injection pulse width T.
The final fuel injection pulse width TI is calculated by adding the invalid pulse width TS corresponding to the battery voltage to E. An injection pulse signal having the fuel injection pulse width TI is output to the fuel injection valve 6, and the fuel injection valve 6 is driven to inject and supply a fuel amount corresponding to the target air-fuel ratio.

In this way, the intake air amount and the fuel supply amount by controlling the throttle valve opening are controlled to their respective target values, so that the target air-fuel ratio is maintained and the exhaust purification performance and the like are maintained. While satisfying the above condition, it is possible to obtain a necessary target engine torque and secure good driving performance. In addition, in the present embodiment, when obtaining the target intake air amount for obtaining the target engine torque with the target air-fuel ratio,
Since the reference target intake air amount that can obtain the target engine torque with the reference air-fuel ratio is calculated and then corrected, the amount of data required for the calculation can be small.

That is, the data for calculating the reference target intake air amount (data stored in the calculation formula or map) is 1
Since it is determined by the target engine torque and the engine speed with respect to one reference air-fuel ratio, the change width (dynamic range) of the data is small and the required data amount can be minimized. For example, 256 in the map (= 16 x 16)
If 256 reference target intake air amount data corresponding to the operating range of each of these areas are stored, and each of these areas is divided into areas having 16 target air-fuel ratios, it corresponds to the target air-fuel ratio. If 16 target equivalence ratio data is used, a total of 272 data will suffice, but if this data is set corresponding to the target air-fuel ratio for each operating region from the beginning, 256 × 16 = 4096 pieces of data are required.

Further, the correction of the reference target intake air amount can also be performed by an extremely simple calculation of only dividing by the target equivalence ratio. Next, a second embodiment will be described with reference to FIG. The target engine torque calculation unit F as a target engine torque calculation unit receives the accelerator operation amount APS and the engine rotation speed Ne, and calculates a target engine torque tTe according to the operating state determined by these. Here, the target engine torque tTe can be substituted with a value given by an external command.

In the reference target intake air amount calculation unit A and the target equivalent ratio calculation unit B, the difference from the first embodiment is that the calculated target engine torque is used instead of inputting the accelerator operation amount APS. tTe is input, and the target engine torque tTe and engine speed N
As in the first embodiment, the target intake air amount tTP at the theoretical air-fuel ratio and the target equivalence ratio tDML corresponding to the target air-fuel ratio are calculated corresponding to the operating state determined by e.

Hereinafter, in the target intake air amount calculation unit C and the target throttle opening calculation unit D, the target intake air amount tT corresponding to the target air-fuel ratio is exactly the same as in the first embodiment.
P ′, a target throttle valve opening tTPS that gives the target intake air amount tTP ′ is calculated, and the throttle valve control device 10
Accordingly, the throttle valve 9 changes the target throttle valve opening t
It is driven so as to be TPS, and thereby, the control in which the target air-fuel ratio and the target engine torque are compatible is performed.

Besides, the same effects as those of the above-described first embodiment can be obtained. Next, a third embodiment will be described with reference to FIG. In this embodiment, a phase operation unit is added to the configuration of the first embodiment. The phase operation unit G calculates a second target equivalent ratio tDML ′ whose phase is delayed with respect to the target equivalent ratio tDML calculated by the target equivalent ratio calculator B.

The correction calculation unit E2 multiplies the basic fuel injection pulse width TP calculated by the basic fuel supply amount calculation unit E1 by the second target equivalent ratio tDML 'input from the phase operation unit to calculate the effective fuel injection pulse width. TE is calculated, and this is corrected by the invalid pulse width TS to calculate the final fuel injection pulse width TI. To delay the phase, first-order lag processing such as weighted averaging is used.

As shown in FIG. 9, the second target equivalent ratio tDM in which the target equivalent ratio tDML is also delayed so as to correspond to the response delay of the intake air amount when the target air-fuel ratio changes.
By supplying the fuel according to L ′, it is possible to prevent the occurrence of the disturbance of the actual engine torque Te during the change of the air-fuel ratio. For example, consider a case where the accelerator operation amount APS or the target engine torque tTe is constant and the target air-fuel ratio is made lean. Since the accelerator operation amount APS or the target engine torque tTe is constant, the reference target intake air amount tT which is the intake air amount required at the stoichiometric air-fuel ratio.
Although P is constant, the target equivalence ratio tDML (= theoretical air-fuel ratio / target air-fuel ratio) becomes smaller as the target air-fuel ratio becomes leaner. Therefore, the target intake air amount tTP ′ corresponding to the target air-fuel ratio tTP / tDML. Becomes larger and the target throttle valve opening tTPS also becomes larger.

On the other hand, since the basic fuel injection pulse width TP increases with a delay due to the response delay of the intake air due to the volume of the intake system, the effective fuel injection pulse width TE obtained as TP × tDML once becomes small, The actual engine torque also decreases once. Here, if the effective fuel injection pulse width TE is TP × tDML ′, the target equivalence ratio tDML ′ is in phase with the response delay of the intake air, and thus such disturbance of the actual engine torque can be avoided.

A fourth embodiment obtained by adding the configuration of the phase operating unit G of the third embodiment to the second embodiment is shown in FIG.
Shown in 10. The effect is similar to that of the third embodiment. Next, a fifth embodiment will be described with reference to FIG. In the present embodiment, a fuel efficiency correction coefficient calculation unit H is added to the configuration of the first embodiment. The fuel consumption rate correction coefficient calculation unit H
The target equivalence ratio tDML is input, and the fuel consumption rate correction coefficient FCrate for correcting the fuel supply amount is calculated according to the lean fuel consumption rate (fuel consumption rate) improvement characteristic described later based on the value corresponding to this target air-fuel ratio. To do.

Then, the target intake air amount calculation unit C'multiplies the fuel consumption rate correction coefficient FCrate by the target intake air amount tTP 'obtained by dividing the reference target intake air amount tTP by the target equivalent ratio tDML. Second target intake air amount tT
P "is calculated. Also, target throttle valve opening calculation VD
Inputs the calculated second target intake air amount tTP "and the engine rotation speed Ne, and calculates the target throttle valve opening tTPS based on these input values.

That is, the amount of fuel required to generate the same engine torque is almost constant regardless of the air-fuel ratio, but as shown in FIG. The larger the air-fuel ratio, the smaller the required fuel amount. Therefore, the target throttle valve opening tTPS is set to the target intake air amount tTP 'by the fuel consumption rate correction coefficient FCrate.
By performing the calculation in accordance with the second target intake air amount tTP ″ obtained by multiplying by, it becomes possible to make a correction according to the improvement of the fuel consumption rate due to the leaning.

In this embodiment, the effect that the torque when the target air-fuel ratio changes can be stabilized with higher accuracy can be obtained. The fuel consumption rate correction coefficient FCrate calculated based on the target equivalent ratio tDML is used as another engine information,
For example, the reference target intake air amount tTP, the engine rotation speed Ne, and the cooling water temperature Tw may be used for correction.

FIG. 13 shows a sixth embodiment in which the configuration of the fuel consumption rate correction coefficient calculation unit H of the fifth embodiment is added to the second embodiment. The effect is similar to that of the fifth embodiment. FIG. 14 shows a seventh embodiment, which is different from the configuration of the first embodiment in that the configuration of the phase operating unit G shown in the third embodiment and the fuel consumption rate correction coefficient shown in the fifth embodiment. The configuration of the calculation unit H is added.

Therefore, in this embodiment, in addition to the basic effect of the first embodiment, the torque stabilizing effect during the change of the air-fuel ratio according to the third embodiment and the lean torque stabilizing effect according to the fifth embodiment. It is possible to obtain the effect. Fig. 15
Shows an eighth embodiment, in which the configuration of the phase operation unit G and the configuration of the fuel consumption rate correction coefficient calculation unit H are added to the configuration of the second embodiment.

The effects of this embodiment are similar to those of the seventh embodiment. Next, a ninth embodiment will be described with reference to FIG. In the present embodiment, the target intake air amount calculation unit X inputs the accelerator operation amount APS and the engine rotation speed Ne, and the target intake air amount tT corresponding to the target air-fuel ratio.
Calculate P'directly.

That is, since the target engine torque and the target air-fuel ratio are simultaneously determined by the accelerator operation amount APS and the engine speed Ne, these (engine speed Ne, target engine torque, target air-fuel ratio) are determined. The second target intake air amount tTP "that simultaneously satisfies the above can be experimentally obtained in advance. The second target intake air amount tTP" is searched from the map storing this data.

In the present embodiment, as described above, the second target intake air amount tTP "is added by the factor of changing the air-fuel ratio as compared with the method of obtaining the reference target intake air amount tTP at the constant reference air-fuel ratio. However, there is a problem that the amount of data increases because the change width (dynamic range) of the data value increases, but the target equivalence ratio tDML and the fuel consumption rate correction coefficient FCrate
Therefore, the number of calculations can be reduced.

It is also possible to increase the accuracy of the data. The fuel consumption rate correction coefficient FCra according to the target air-fuel ratio
This is because the data corrected by te is given, and as the fuel consumption rate correction coefficient FCrate, a value that finely corresponds to the target torque for each region can be used.
The tenth embodiment is shown in FIG.

In this embodiment, the target engine torque t is once calculated from the accelerator operation amount APS and the engine rotation speed Ne.
Te is calculated, and the second target intake air amount tTP ″ is obtained from the target engine torque tTe and the engine rotation speed Ne. Other configurations are the same as those in the ninth embodiment. , The same effect can be obtained.
Embodiments in which the configuration of the phase operating unit G is omitted in the ninth and tenth embodiments are also possible.

Next, an embodiment will be described in which the control accuracy is further improved in the case where the control is performed through the setting of the target engine torque. FIG. 18 shows the present embodiment, and the target engine torque calculation unit calculates the target engine torque tTe from the accelerator operation amount APS and the engine rotation speed Ne by referring to the map, as in the above embodiment. Then, the target engine torque map is the accelerator operation amount APS when the engine rotation speed Ne is constant.
When the accelerator operation amount APS changes by a unit amount or more as shown in the figure, the absolute value of the target engine torque tTe change amount for the target engine torque tTe
The target engine torque tTe is set to be equal to or larger than the (controllable) minimum unit amount.

Further, the target intake air amount calculation unit calculates the target intake air amount tTP based on the target engine torque tTe and the engine rotation speed Ne by referring to a map or the like. When fixed, the target intake air amount tTP is proportional to the target engine torque tTe. The target opening area calculator calculates the target opening area tATVO of the intake air passage from the map based on the target intake air amount tTP and the engine rotation speed Ne. The target opening area map is a constant engine rotation speed Ne. Is a monotonically increasing function with respect to the target intake air amount tTP, and the target intake air amount t
Where the TP is large, the increase rate of the target opening area tATVO (ΔtATVO / ΔtTP) increases, but
The rate of increase can be suppressed below a predetermined level.

The target throttle valve opening calculator calculates a target throttle valve that monotonically increases as shown with respect to the target opening area tATVO that monotonically increases with respect to the target intake air amount tTP or the target engine torque tTe as described above. The opening degree tTPS is calculated. In this way, the target engine torque tTe is not saturated even in the region where the accelerator operation amount APS is large with respect to the accelerator operation amount APS, and is monotonically increased, so that the control accuracy is improved. The reason is described below.

When the target torque map is set based on general engine performance as shown in FIG. 19, theoretically, the intake air amount is saturated when the throttle valve opening is a predetermined amount or more, and the engine torque is also saturated accordingly. To do. Therefore, if the relationship between the accelerator operation amount APS and the target engine torque tTe is set to a characteristic like the dotted line in the figure that is close to the relationship between the throttle valve opening and the engine torque, the accelerator operation amount A
If PS exceeds a certain value, the increase rate ΔtTe / ΔAPS of the target engine torque tTe becomes extremely small.

A computer for controlling the engine (hereinafter referred to as E
(CM) generally uses fixed-point arithmetic, so the smaller the absolute value of the numerical value to be handled, the smaller the number of significant digits. That is, the calculation accuracy decreases. As described above, in the saturation region of the target engine torque tTe, the increase rate ΔtTe becomes small, so that the calculation accuracy of ΔtTe decreases.

Further, since the target engine torque tTe and the target opening area tATVO have a substantially inverse function relationship,
When the target intake air amount tTP exceeds a certain value, the target opening area tATVO rises sharply as shown by the dotted line (ΔtATVO / ΔtTP becomes very large). Therefore, the error of the target intake air amount tTP is increased as ΔtATVO / ΔtTP increases, and the target opening area tATV is increased.
It appears in the error of O.

On the other hand, in the saturation region of the target engine torque tTe, the calculation accuracy of ΔtTe is low and the target engine torque tTe and the target intake air amount tTP are proportional to each other.
The calculation accuracy of TP is also reduced, and the accuracy of ΔtATVO is significantly reduced due to the synergistic effect with the above error expansion, and as a result, the calculation accuracy of the target opening area tATVO and thus the target throttle valve opening tTPS is also reduced.

From the above, the following problems occur. The accuracy of the throttle valve opening control in the target engine torque tTe saturation region is greatly reduced compared to the non-saturation region. The error in the actual engine torque due to this may be positive or negative, and it is considered that the influence on the drivability is not small such that the actual engine torque decreases even when the accelerator is stepped on.

Further, when the target opening area tATVO in the saturation region of the target engine torque tTe continues to cause an error, the throttle valve does not open until it is fully opened. As a result, the maximum torque cannot be generated, and the operation is stopped. It may affect sex. In view of such problems,
In the present embodiment, the target engine torque tTe is not saturated with respect to the accelerator operation amount APS even in a region where the accelerator operation amount APS is large, and is increased monotonically at a predetermined increase rate, so that the calculation accuracy of ΔtTe is improved. In addition, since the increase rate of ΔtATVO / ΔtTP decreases, the target opening area tATV accompanying the error of the target intake air amount tTP
The spread of O error can be suppressed low. Then, the synergistic effect of these can greatly improve the control accuracy of the target opening area tATVO and thus the target throttle valve opening tTPS.

Further, if the maximum value of the target engine torque tTe is set higher than the maximum value of the actual engine torque, the throttle valve can be reliably operated even if the detected value of the accelerator operation amount has a low error. It can be fully opened, and it is possible to reliably prevent unpleasant characteristics such as a decrease in torque even when the accelerator is depressed. As the target engine torque tTe used when the target intake air amount calculation unit obtains the target intake air amount tTP, the target engine torque tTe obtained from the target engine torque map may be used as it is, but the idle rotation control (ISC) and the like. When there is an electric load or the like, a value that is added to these is used as the target engine torque tTe, so that control that is more suitable for the required engine torque can be performed.

Further, the target engine torque map is
Target intake air amount t corresponding to target engine torque tTe
A target engine torque t that is used only to create a target opening area map via TP, and is used when the target intake air amount calculator calculates the target intake air amount tTP in actual control.
Te is a target engine torque tTe calculated based on the driving force and the gear shift position of the transmission, for example, based on the driving state of a vehicle equipped with the engine.
Can be used, and control can be performed according to a more actual state.

Further, in the present embodiment, only the control of the intake air amount by the throttle valve opening control is shown, but the control of the fuel supply amount may be performed in the same manner as the above-mentioned embodiment. Therefore, the present embodiment can also be applied to one including the target engine torque calculation unit in each of the above-described embodiments.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration and a function of an invention according to claim 3;

FIG. 2 is a block diagram showing the configuration and function of the invention according to claim 4;

FIG. 3 is a block diagram showing a configuration and a function of the invention according to claim 8;

FIG. 4 is a block diagram showing the configuration and function of the invention according to claim 9;

FIG. 5 is a diagram showing a system configuration of an embodiment of the present invention.

FIG. 6 is a block diagram showing a functional configuration of the first embodiment.

FIG. 7 is a block diagram showing a functional configuration of a second embodiment.

FIG. 8 is a block diagram showing a functional configuration of a third embodiment.

FIG. 9 is a time chart showing the operation of the third embodiment.

FIG. 10 is a block diagram showing a functional configuration of a fourth embodiment.

FIG. 11 is a block diagram showing a functional configuration of a fifth embodiment.

FIG. 12 is a diagram showing a relationship between an air-fuel ratio, a required air amount, and a required fuel amount.

FIG. 13 is a block diagram showing a functional configuration of a sixth embodiment.

FIG. 14 is a block diagram showing a functional configuration of a seventh embodiment.

FIG. 15 is a block diagram showing a functional configuration of an eighth embodiment.

FIG. 16 is a block diagram showing a functional configuration of a ninth embodiment.

FIG. 17 is a block diagram showing a functional configuration of a tenth embodiment.

FIG. 18 is a block diagram showing a functional configuration of an eleventh embodiment.

FIG. 19 is a diagram showing a relationship between engine torque and throttle valve opening and engine speed.

[Explanation of symbols]

 1 accelerator operation amount sensor 2 crank angle sensor 3 air flow meter 4 engine 5 water temperature sensor 6 fuel injection valve 9 throttle valve 10 throttle valve control device 11 control unit A reference target intake air amount calculation unit B target equivalent ratio calculation unit C target intake air Amount calculation unit C'Target intake air amount calculation unit D Target throttle valve opening calculation unit E1 Basic fuel supply amount calculation unit E2 Correction calculation unit F Target engine torque calculation unit G Phase operation unit H Fuel consumption correction coefficient calculation unit X Target intake air Quantity calculator

Claims (13)

[Claims] 1. A torque control device for an engine, which controls an intake air amount and a fuel supply amount so that a target engine torque and a target air-fuel ratio according to an operating state of the engine are obtained. 2. The control of the intake air amount is performed by controlling the opening of the throttle valve by a throttle valve control device that controls the opening of the throttle valve interposed in the intake system of the engine to a target value. The torque control device for an engine according to claim 1, wherein 3. A throttle valve control device for controlling the opening of a throttle valve interposed in an intake system of an engine to a target value,
A torque control device for an engine, comprising: a fuel supply amount control device for controlling an amount of fuel supplied to an engine to a target value; an accelerator operation amount detecting means for detecting an accelerator operation amount; and an engine for detecting an engine rotation speed. Based on the rotational speed detecting means, the intake air amount detecting means for detecting the intake air amount to the engine, and the reference target intake air corresponding to the reference air-fuel ratio based on the detected accelerator operation amount and the detected engine rotational speed. A reference target intake air amount calculation means for calculating an air amount, and a target corresponding to a target air-fuel ratio by correcting the reference target intake air amount based on the detected accelerator operation amount and the detected engine rotation speed. Target intake air amount calculation means for calculating the intake air amount, based on the target intake air amount and the engine speed,
A target throttle valve opening calculation means for calculating a target throttle valve opening, and a fuel for calculating a fuel supply amount based on the intake air amount, the engine speed and the target air-fuel ratio detected by the intake air amount detection means. Supply amount calculation means, and the throttle valve control device controls the opening of the throttle valve so as to reach the calculated target throttle valve opening, and the fuel supply amount control device A torque control device for an engine, which controls the engine torque to a target value by controlling the fuel supply amount so as to be the calculated fuel supply amount. 4. A throttle valve control device for controlling an opening of a throttle valve interposed in an intake system of an engine to a target value,
A torque control device for an engine, comprising: a fuel supply amount control device for controlling an amount of fuel supplied to an engine to a target value; an accelerator operation amount detecting means for detecting an accelerator operation amount; and an engine for detecting an engine rotation speed. A target engine based on the rotational speed detecting means, the intake air amount detecting means for detecting the intake air amount to the engine, the detected accelerator operation amount and the detected engine rotational speed, or by a command from the outside. Target engine torque calculating means for calculating torque, based on the calculated target engine torque and engine speed, reference target intake air amount calculating means for calculating a reference target intake air amount corresponding to the reference air-fuel ratio, Target intake air amount calculation for correcting the reference target intake air amount and calculating the target intake air amount corresponding to the target air-fuel ratio And stage, the based on the target intake air amount and the engine rotational speed,
A target throttle valve opening calculation means for calculating a target throttle valve opening, and a fuel for calculating a fuel supply amount based on the intake air amount, the engine speed and the target air-fuel ratio detected by the intake air amount detection means. Supply amount calculation means, and the throttle valve control device controls the opening of the throttle valve so as to reach the calculated target throttle valve opening, and the fuel supply amount control device A torque control device for an engine, which controls the engine torque to a target value by controlling the fuel supply amount so as to be the calculated fuel supply amount. 5. A target equivalence ratio computing means for computing a target equivalence ratio corresponding to a reference air-fuel ratio / target air-fuel ratio based on the detected accelerator operation amount and the detected engine speed. The target intake air amount calculating means calculates a target intake air amount by dividing the reference target intake air amount by the target equivalent ratio, and the fuel supply amount calculating means is detected by the intake air amount detecting means. 4. The fuel supply amount is calculated by multiplying the fuel supply amount corresponding to the reference air-fuel ratio calculated based on the intake air amount and the engine speed, by the target equivalence ratio. 4. The engine torque control device according to item 4. 6. The target equivalence ratio calculation means calculates a second target equivalence ratio with a delayed phase, and the fuel supply amount calculation means calculates the intake air amount and engine speed detected by the intake air amount detection means. The fuel supply amount corresponding to the reference air-fuel ratio calculated based on the speed and the second
The engine torque control device according to claim 5, wherein the fuel supply amount is calculated by multiplying the target equivalence ratio. 7. A fuel consumption rate correction coefficient calculation means for calculating a fuel consumption rate correction coefficient according to the target equivalence ratio is included, and the target throttle valve opening calculation means calculates the fuel consumption rate according to the target intake air amount. 7. The engine torque control device according to claim 5, wherein the target throttle valve opening is calculated based on the second target intake air amount and the engine speed obtained by multiplying the correction coefficient. . 8. A throttle valve control device for controlling an opening of a throttle valve interposed in an intake system of an engine to a target value,
A torque control device for an engine, comprising: a fuel supply amount control device for controlling an amount of fuel supplied to an engine to a target value; an accelerator operation amount detecting means for detecting an accelerator operation amount; and an engine for detecting an engine rotation speed. A rotation speed detecting means, an intake air amount detecting means for detecting an intake air amount to the engine, and a target intake air amount corresponding to a target air-fuel ratio based on the detected accelerator operation amount and the detected engine rotation speed. Target intake air amount calculation means for calculating the amount, based on the target intake air amount and the engine speed,
A target throttle valve opening calculation means for calculating a target throttle valve opening, and a fuel for calculating a fuel supply amount based on the intake air amount, the engine speed and the target air-fuel ratio detected by the intake air amount detection means. Supply amount calculation means, and the throttle valve control device controls the opening of the throttle valve so as to reach the calculated target throttle valve opening, and the fuel supply amount control device A torque control device for an engine, which controls the engine torque to a target value by controlling the fuel supply amount so as to be the calculated fuel supply amount. 9. A throttle valve control device for controlling the opening of a throttle valve interposed in an intake system of an engine to a target value,
A torque control device for an engine, comprising: a fuel supply amount control device for controlling an amount of fuel supplied to an engine to a target value; an accelerator operation amount detecting means for detecting an accelerator operation amount; and an engine for detecting an engine rotation speed. A target engine based on the rotational speed detecting means, the intake air amount detecting means for detecting the intake air amount to the engine, the detected accelerator operation amount and the detected engine rotational speed, or by a command from the outside. Target engine torque calculating means for calculating torque; target intake air amount calculating means for calculating a target intake air amount corresponding to a target air-fuel ratio based on the calculated target engine torque and engine speed; Based on the intake air amount and the engine speed,
A target throttle valve opening calculation means for calculating a target throttle valve opening, and a fuel for calculating a fuel supply amount based on the intake air amount, the engine speed and the target air-fuel ratio detected by the intake air amount detection means. Supply amount calculation means, and the throttle valve control device controls the opening of the throttle valve so as to reach the calculated target throttle valve opening, and the fuel supply amount control device A torque control device for an engine, which controls the engine torque to a target value by controlling the fuel supply amount so as to be the calculated fuel supply amount. 10. An accelerator operation amount detection means for detecting an accelerator operation amount, an engine rotation speed detection means for detecting an engine rotation speed, and based on the detected accelerator operation amount and the detected engine rotation speed, Alternatively, a target engine torque calculating means for calculating a target engine torque by a command from the outside, and a target intake air amount calculating means for calculating a target intake air amount based on the calculated target engine torque and engine rotation speed. , Based on the target intake air amount and the engine speed,
A target throttle valve opening calculation means for calculating a target throttle valve opening, and an engine torque control device for controlling the opening of a throttle valve interposed in an intake system of the engine to the calculated target throttle valve opening. , Reference is made according to one or more inputs including at least the accelerator operation amount, and when the accelerator operation amount changes by a unit amount or more, a target engine torque map in which the absolute value of the target engine torque change amount for this is a minimum unit amount or more is displayed. A target opening area map is set in which the target opening area of the intake air passage is set based on the operating state determined by the target engine torque map, and the target throttle valve opening calculation means calculates the intake air from the target opening area map. By referring to the target opening area of the passage, the target slot according to the referred target opening area of the intake air passage. Torque control system for an engine, characterized by calculating the torque valve opening. 11. The target engine torque calculating means calculates the target engine torque by referring to the target engine torque map based on an accelerator operation amount and an engine rotation speed. Engine torque control device. 12. The target engine torque calculation means calculates the target engine torque based on a target driving force of a vehicle equipped with an engine and a gear shift position of a transmission. Engine torque control device. 13. The engine torque control device according to claim 10, wherein any one of claims 4, 5, 6, 7 and 9 is satisfied.