JP2001355501A - Engine control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the intake air flow controllability by controlling each actuator of an intake air flow adjusting means and a supercharger to each target value. SOLUTION: A supercharger 31 is driven by an actuator suitable for the revolving speed control. A computing means 34 computes a target air flow on the basis of the accelerator operated variable, and a computing means 35 sets a target supercharge pressure in response to the target air flow. A computing means 36 computes a target value of an intake air flow adjusting means 32 on the basis of the target air flow and the target supercharge pressure, and a computing means 37 computes a target revolving speed of the supercharger 31 on the basis of the target air flow and the target supercharge pressure. The described target value is given to the actuator of the intake air flow adjusting means 32 so as to drive a driving means 38, and a driving means 39 drives the actuator of the supercharger 31 at the target revolving speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an engine control device.

[0002]

2. Description of the Related Art When a centrifugal supercharger (turbocharger) is provided, the supercharging action of the supercharger does not work in a low rotation range, and a high rotation range side in which a throttle valve is opened to a predetermined opening degree or more. By operating the throttle valve, the target air amount is calculated based on the accelerator operation amount when the accelerator operation amount is equal to or less than a predetermined value, and the throttle valve opening is controlled to obtain the target air amount. When the accelerator operation amount exceeds a predetermined value,
There has been proposed a system in which a target supercharging pressure is calculated based on an accelerator operation amount with a throttle valve fully opened, and a supercharging pressure of a supercharger is controlled so as to obtain the target supercharging pressure ( See JP-A-61-83460).

[0003]

In the conventional device, the non-supercharging region and the supercharging region are divided depending on whether the accelerator operation amount is equal to or less than a predetermined value. Since the intake air amount is controlled only by the supercharging pressure in the supercharging region, the supercharging pressure control accuracy and responsiveness when connecting from the non-supercharging region to the supercharging region are reduced. If not, it is difficult to control the amount of intake air. If the control fails, a step or delay in torque is generated, resulting in poor drivability. On the other hand, in order to control the intake air amount in the supercharging region with the same control accuracy and responsiveness as in the non-supercharging region, the demand for a mechanism for adjusting the supercharging pressure becomes severe and the cost and weight increase. I will.

Accordingly, the present invention calculates a target air amount based on an accelerator operation amount for a turbocharger driven by an actuator (for example, an AC motor) of a type suitable for controlling the rotational speed. And set the target boost pressure according to the target air amount,
Based on the target air amount and the target supercharging pressure, a target value of the intake air amount adjusting means (target opening of the throttle valve) and a target rotation speed of the supercharger are simultaneously calculated, and the intake air amount adjusting means, the supercharger It is an object of the present invention to improve the controllability of the intake air amount and improve the torque operability by performing cooperative control of the respective actuators according to the respective target values.

In the case of a supercharger driven by an actuator (for example, a DC motor having no rotation speed control mechanism) that is not suitable for performing the rotation speed control, a passage that bypasses the supercharger is used. By providing a bypass valve that can adjust the amount of air flowing through the actuator by an actuator, and controlling the opening degree of this bypass valve to replace the rotation speed control of the turbocharger, the actuator of the turbocharger controls the rotation speed. It is an object of the present invention to improve the controllability of the intake air amount and improve the torque operability even in a case where the type is not suitable for the operation.

[0006]

According to a first aspect of the present invention, as shown in FIG. 15, a supercharger 31 driven by an actuator (for example, an AC motor) suitable for controlling the rotational speed, A means (for example, a throttle valve) 32 capable of adjusting the air amount by an actuator, a means 33 for detecting an accelerator operation amount, a means 34 for calculating a target air amount tQa based on the accelerator operation amount, Means 35 for setting the target supercharging pressure tPc in response thereto, and means for calculating the target value (the target opening of the throttle valve) of the intake air amount adjusting means 32 based on the target air amount tQa and the target supercharging pressure tPc. 36, means 37 for calculating a target rotational speed of the supercharger 31 based on the target air amount tQa and the target supercharging pressure tPc, and the intake air amount adjusting means 32. It provided with means 38 for driving the actuator by applying the target value, and means 39 for driving the actuator of the turbocharger 31 at the target rotation speed.

In a second aspect of the present invention, a target supercharging pressure ratio ηpc which is a ratio to a standard pressure is used in place of the target supercharging pressure in the first aspect.

A third aspect of the present invention, as shown in FIG. 16, is a type of actuator not suitable for controlling the rotational speed (for example, a DC motor without a rotational speed control mechanism).
, A bypass valve 52 capable of adjusting the amount of air flowing through a passage bypassing the supercharger 51 by an actuator, and a means (eg, a throttle valve) 32 capable of adjusting the amount of intake air by an actuator.
Means 33 for detecting the accelerator operation amount, and means 34 for calculating the target air amount tQa based on the accelerator operation amount
Means 35 for setting a target supercharging pressure tPc in accordance with the target air amount tQa, and a target value (a throttle valve setting) of the intake air amount adjusting means 32 based on the target air amount tQa and the target supercharging pressure tPc. Means 36 for calculating target opening)
A target opening degree of the bypass valve 52 based on the target air amount tQa in the non-supercharging region and the total air flow amount passing through the supercharger 51 in the supercharging region. 53, and the intake air amount adjusting means 32
Means 3 for driving the actuator by giving the target value to the actuator
8 and means 54 for driving the actuator of the bypass valve 52 by giving the target opening degree.

According to a fourth aspect of the present invention, in the third aspect, the means for calculating the total flow rate of air passing through the supercharger 51 includes a means for detecting a rotational speed of the supercharger 51, From the supercharging pressure ratio when the turbocharger is operated in the supercharging range and the supercharger rotation speed detected by the detection means.
Means for calculating the total air flow rate passing through.

According to a fifth aspect of the present invention, in the third or fourth aspect, a target supercharging pressure ratio ηpc which is a ratio to a standard pressure is used instead of the target supercharging pressure.

In a sixth aspect based on the second or fifth aspect, the actuator of the supercharger is a motor.

In a seventh aspect, in the sixth aspect, when the target value of the intake air amount adjusting means 32 is the target opening degree of the throttle valve, the means for calculating the target opening degree of the throttle valve is: Means for calculating a target air amount when the throttle valve upstream is in a standard state using the target air amount and the target supercharging pressure ratio; and a target opening degree of the throttle valve based on the target air amount when the throttle valve upstream is in a standard state. And means for calculating.

According to an eighth aspect, in the sixth aspect, the target boost pressure ratio is set to 1 when the target air amount is equal to or less than the maximum air amount during natural intake.

In a ninth aspect, in the second aspect, the means for calculating the target rotational speed of the supercharger includes: means for calculating a total air flow rate passing through the supercharger based on the target air amount; Means for calculating a target rotational speed of the supercharger by searching a supercharger characteristic map from the total air flow rate and the supercharging pressure ratio.

According to a tenth aspect, in any one of the first to ninth aspects, the means for calculating the target air amount is means for calculating a target driving force based on an accelerator operation amount and a vehicle speed. It comprises means for converting the target driving force into a target gear ratio for the transmission and a target engine torque, and means for calculating a target air amount based on the target engine torque.

[0016]

According to the first and second aspects of the present invention, a supercharger driven by an actuator of a type suitable for controlling the rotational speed is targeted based on a target air amount and a target supercharging pressure. The target value of the intake air amount adjustment means and the target rotation speed of the supercharger are simultaneously calculated, and the intake air amount adjustment means and the actuators of the supercharger are cooperatively controlled according to the respective target values. In addition to being free, the controllability of the amount of intake air is improved, thereby improving the torque operability.

According to the third, fourth and fifth aspects of the present invention, when a turbocharger driven by an actuator which is not suitable for controlling the rotational speed is targeted, the opening degree of the bypass valve is controlled. According to the third and fourth aspects of the present invention, a case where a turbocharger driven by an actuator that is not suitable for performing the rotational speed control is targeted for replacing the turbocharger rotational speed control. The same effects as those of the first and second inventions can be obtained.

According to the motor, the supercharger can be driven with good response, and the controllability of the intake air amount is further improved. Therefore, in the sixth aspect, the connection from the non-supercharged region to the supercharged region is further smoothed.

According to the seventh aspect, the setting of the supercharging pressure in the supercharging region and the setting of the throttle valve opening can be performed in a coordinated manner, whereby the connection from the non-supercharging region to the supercharging region can be achieved. Is performed more smoothly.

If the supercharger is operated until the target air amount is obtained by natural aspiration, the supercharged work is wasted as much as the supercharged work. However, according to the eighth aspect, the supercharged work may be wasted. Supercharging can be performed efficiently without any problems.

According to the ninth aspect, since the characteristics of the turbocharger alone can be used as it is, adaptation such as setting of the target supercharging pressure ratio according to the target air amount can be easily performed.

According to the tenth aspect, since the driving force required by the driver can be realized, driving performance and power performance can be improved.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, 1 is an engine body, 2 is an intake passage, 3 is an exhaust passage, 4 is a fuel injection valve provided directly facing a combustion chamber 5, and 6 is a spark plug.

In the intake passage 2 of the engine, a so-called electronically controlled throttle device for opening and closing a throttle valve 8 (intake air amount adjusting means) by a DC motor 9 or the like is interposed, and is detected by a throttle sensor (not shown). The throttle valve 8 is driven such that the actual opening degree coincides with the target opening degree command from the control unit 21.
The amount of air taken into the engine is adjusted according to the opening of the throttle valve 8 determined at this time.

The control unit 21 has a position signal and a reference position signal for each unit crank angle from the crank angle sensor 23, a signal of the amount of intake air from the air flow meter 24, a signal of the cooling water temperature from the water temperature sensor 25, and the exhaust passage 3. Signals from an oxygen concentration sensor (not shown) are input to the control unit 21 so that a fuel mixture having a predetermined air-fuel ratio (stoichiometric air-fuel ratio or lean air-fuel ratio) is obtained based on these signals. An injection pulse width is calculated, and fuel is injected from the fuel injection valve 4 according to the calculated value.

An AC motor 12 is provided upstream of the throttle valve 8.
Is provided, and the supercharger 11 supercharges air taken into the engine.

A bypass passage 13 is provided which bypasses the supercharger 11 and joins upstream of the throttle valve 8.
A bypass valve 14 driven by a step motor 15 is interposed in the bypass passage 13.

The control unit 21 also receives a signal of an accelerator operation amount from the accelerator sensor 22. The control unit 21 calculates a target air amount based on the accelerator operation amount signal and sets a target air amount in accordance with the target air amount. A supercharging pressure ratio is set, and a target opening of the throttle valve 8 and a target rotation speed of the supercharger 11 are simultaneously calculated based on the target air amount and the target supercharging pressure ratio. The actuators are cooperatively controlled according to the respective target values.

The contents of the cooperative control executed by the control unit 21 will be described with reference to the following flowchart.

FIG. 2 shows respective target values of the DC motor 9 as the throttle valve actuator, the AC motor 12 as the supercharger actuator, and the step motor 15 as the bypass valve actuator (the target opening of the throttle valve 8, the supercharger 11). Target rotation speed, target opening of bypass valve 14)
Is calculated at regular intervals (for example, 10 m
s).

In step 1, the accelerator operation amount and the engine rotation speed Ne are read. In step 2, a map having the contents shown in FIG. 3 is retrieved from them to obtain the target air amount tQa per cycle and per cylinder.
Calculate [kg / cycle cylinder]. This amount of air is hereinafter simply referred to as “target air amount”.

The method of calculating the target air amount tQa is not limited to this. As shown in FIG. 4, a target driving force determined from the driving performance / power performance is obtained based on the accelerator operation amount and the vehicle speed. A target speed ratio for a continuously variable transmission (automatic transmission) such as a CVT and a target engine torque are converted to a target engine torque, and an air amount for realizing the target engine torque is converted to a target air amount t.
It may be calculated as Qa. More specifically, the target driving force calculating means 11 calculates the target driving force by searching a map having the contents shown in FIG. 5 from the accelerator operation amount and the vehicle speed (both are detected by sensors). The target gear ratio calculating means 12 calculates the target gear ratio by searching a map having the contents shown in FIG. 6 from the accelerator operation amount and the vehicle speed. In the target engine torque calculating means 13 to which the target gear ratio and the target driving force are input,

[0033]

## EQU1 ## The target engine torque tTe is calculated by the following equation: target engine torque = target driving force / (target gear ratio × final gear ratio × tire effective radius), and the target air amount is calculated from the target engine torque tTe and the engine rotation speed Ne. The calculating means 14 calculates the target air amount tQa by searching a map having the contents shown in FIG.

FIG. 6 is a shift control map in which the target gear ratio is determined in advance by the accelerator operation amount and the vehicle speed. In the figure, the characteristic of the constant gear ratio is a straight line having a certain slope. For example, assuming that the straight line L is a target gear ratio, and a point U determined by the vehicle speed and the accelerator operation amount is taken on the straight line L, the value on the vertical axis with respect to this point U becomes the target input rotation speed (= engine rotation speed) of the transmission. Become. Therefore, when the automatic transmission is controlled to attain this target rotational speed, a target gear ratio is obtained.

Returning to FIG. 2, in step 3, as shown in FIG. 8, the target supercharging pressure ratio ηpc is set according to the target air amount tQa. The target supercharging pressure ratio ηpc is a value obtained by dividing the target supercharging pressure tPc by the pressure P0 in a standard state (temperature is 20 ° C., pressure is 1 atm) (that is, 1 atm). In FIG. 8, when it is desired to minimize the power loss due to the supercharging, the supercharging pressure ratio ηpc = 1 may be set so as to set the non-supercharging region to the maximum air amount at the time of NA (natural intake) (see the solid line). And, in order to respond to the demand of the air amount more than that, the boost pressure ratio ηpc is set to 1.0.
(See solid line).

On the other hand, if it is desired to always set the supercharging pressure to the maximum, the pressure is set as shown by a one-dot chain line. At this time, the target air amount is obtained by controlling the throttle valve opening.

In FIG. 8, the maximum air amount at NA is determined by the engine displacement, and the maximum air amount is determined by the actual performance of the engine.

Returning to FIG. 2, steps 4 and 5 are for calculating the target throttle valve opening. First, in step 4,
From the target air amount tQa and the target supercharging pressure ratio ηpc

[0039]

The virtual target air amount tQa0 is calculated by the equation tQa0 = tQa / ηpc. Since the amount of air taken into the engine is proportional to the supercharging pressure upstream of the throttle valve 8, the value obtained by dividing the target air amount tQa by the supercharging pressure ratio ηpc is the target value when the upstream of the throttle valve 8 is in the standard state. Since the air amount is obtained, the target air amount when the upstream of the throttle valve 8 is in the standard state is obtained as the virtual target air amount tQa0.

In step 5, this virtual target air amount tQa
The target throttle valve opening for realizing the virtual target air amount tQa0 is calculated by searching a map having the contents shown in FIG. 9 from 0 and the engine speed Ne.

Steps 6 and 7 are for calculating the target rotational speed of the supercharger 11. In general, as shown in FIG. 10, in the positive displacement supercharger, the target air amount tQa is determined in step 6 because the supercharger rotation speed is determined by the total air flow rate passing through the supercharger and the supercharging pressure ratio. From [kg / cycle / cylinder] and engine speed Ne [rpm]

[0042]

## EQU3 ## Total air flow rate [kg / s] = tQa × (Ne / 6
0) × (CYL / 2), where CYL is the number of cylinders, and the total air flow rate is calculated. From the total air flow rate and the target supercharging pressure ratio ηpc, a map having the contents shown in FIG. Thereby, the target rotation speed of the supercharger 11 is calculated.

In step 8, the target bypass valve opening is calculated. This calculation will be described with reference to the flowchart of FIG. In FIG. 11, in step 21, the target supercharging pressure ratio ηp
c, the target throttle valve opening is read, and the target supercharging pressure ratio ηpc is compared with 1.0 in step 22. When the target supercharging pressure ratio ηpc is greater than 1.0 (supercharging range), the target bypass valve opening is set to zero in step 23, that is, the bypass valve 14 is fully closed.
When c is 1.0 or less (non-supercharging region), the bypass valve 14
In step 24, the target bypass valve opening is calculated by searching a predetermined table from the target throttle valve opening so that the throttle does not become the throttle. The table characteristics are not shown because they cannot be unambiguously determined, but the point is that the table characteristics are set so as to satisfy the relationship shown in FIG. That is, FIG.
2, if the straight line L1 is a characteristic when the throttle valve opening area and the bypass valve opening area are 1: 1, the target throttle valve is adjusted so as to satisfy the relationship of the straight line L2 raised by a certain area increase ΔA. The characteristic of the target bypass valve opening degree with respect to the opening degree is set.

The reason why the target bypass valve opening is set depending on the target throttle valve opening in the non-supercharging region and the bypass valve 14 is not fully opened for the following reason is as follows. When the bypass valve 14 is always fully opened in the non-supercharged region, and when the accelerator pedal is greatly depressed to make a transition from the non-supercharged region to the supercharged region, the bypass valve 14 is completely closed from the fully open state to the fully closed state. It takes time, and during this time, the boost pressure does not develop and the rise of the intake air amount (engine torque) is delayed. Therefore, in the non-supercharging region, the bypass valve opening area is set slightly larger than the opening area of the throttle valve 8 so that the bypass valve 14 does not become a throttle and the air passing through the throttle valve 8 flows sufficiently. It was made. Note that the area increase ΔA in FIG. 12 depends on the layout of the intake passage, the intake passage volume, and the intake passage diameter, and may be determined by matching.

The target throttle valve opening, target rotational speed, and target bypass valve opening calculated in this manner are controlled variables given to the actuators of the throttle valve 8, the supercharger 11, and the bypass valve 14 in a flow (not shown). And this control amount is output to each actuator.

Here, the operation of the present embodiment will be described with reference to FIG. 13. FIG. 13 shows the throttle valve opening of the present embodiment when the accelerator operation is performed in three stages from slight to large. In addition to the changes in the turbocharger rotation speed and the bypass valve opening, actual changes in the supercharging pressure and the intake pressure are also modeled.

<1> When the accelerator operation amount APO of the driver is small: Since the target air amount tQa is also small and the non-supercharging region is set, the supercharger 11 stops rotating and the bypass valve 14 is turned off. The opening of the throttle valve 8 is set to be larger than the opening area. The opening of the throttle valve 8 is small, and the amount of intake air is controlled by the opening of the throttle valve at this time.

The supercharging pressure Pc upstream of the throttle valve 8 is equal to the atmospheric pressure, and the intake pressure Pm is throttled by the throttle valve 8 and is lower than the atmospheric pressure.

<2> When the accelerator operation amount APO is increased: Although the target air amount tQa is increased as compared with the case of <1>, the supercharger 11 stops rotating because the non-supercharge area is still set. . The throttle valve 8 is opened more than the accelerator operation amount in order to increase the air amount in the NA state, and the intake air amount is controlled by the throttle valve opening at this time.
The bypass valve 14 is also opened to near full open so as to have an area larger than the opening area of the throttle valve 8.

At this time, the supercharging pressure Pc upstream of the throttle valve 8 is equal to the atmospheric pressure due to the NA state, and the intake pressure Pm
Increases in response to the opening of the throttle valve 8.

<3> When the accelerator operation amount APO further increases: When the target air amount tQa also increases and enters the supercharging region, the bypass valve 14 is fully closed, and the supercharger 11 is driven at the target rotation speed. . The intake air amount is controlled by the supercharging pressure while keeping the opening of the throttle valve 8 almost unchanged. At this time, the supercharging pressure Pc and the intake pressure Pm become equal,
The value is larger than the atmospheric pressure.

As described above, in the present embodiment, the provision of the motor-driven supercharger 11 enables the supercharger 11 to be driven responsively, and the target air amount tQa is determined based on the accelerator operation amount indicating the driver's request. The target supercharging pressure ratio ηpc is set in accordance with the target air amount tQa, and the target opening degree of the throttle valve 8 and the target rotation speed of the supercharger 11 are calculated based on the target air amount tQa and the target supercharging pressure ratio ηpc. At the same time, and the actuators of the throttle valve 8 and the supercharger 11 are coordinately controlled in accordance with their respective target values. Therefore, the controllability of the intake air amount is improved, the torque operability is improved, and the The connection from the supply area to the supercharge area can be performed smoothly.

By setting the target supercharging pressure ηpc according to the target air amount tQa, the supercharging region can be set freely (see FIG. 8).

The target air amount tQa and the target supercharging pressure ratio η
The target air amount upstream of the throttle valve 8 in the standard state is calculated as a virtual target air amount tQa0 using the pc, and the target opening of the throttle valve 8 is calculated based on the virtual target air amount tQa0. The setting of the supercharging pressure and the setting of the throttle valve opening in the region can be performed in cooperation with each other, whereby the connection from the non-supercharging region to the supercharging region is further smoothed.

Further, if the supercharger is operated until the target air amount is obtained by natural aspiration, the supercharger is wasted as much as the supercharging work. However, the target air amount tQa is less than the maximum air amount in the natural aspiration. At this time, since the target supercharging pressure ratio ηpc is set to 1.0, supercharging can be performed efficiently without waste of supercharging work.

Further, a total air flow rate passing through the supercharger 11 is calculated based on the target air amount tQa, and a supercharger characteristic map (FIG. 10) is retrieved from the total air flow rate and the supercharging pressure ratio ηpc. Since the target rotation speed of the turbocharger 11 is calculated, the characteristics of the turbocharger alone can be used as it is, and thereby the target supercharging pressure ratio ηp according to the target air amount tQa.
Adaptation such as setting of c can be easily performed.

Further, a target driving force is calculated based on the accelerator operation amount and the vehicle speed, and the target driving force is converted into a target speed ratio for the continuously variable transmission and a target engine torque. By calculating the air amount, the driving force required by the driver can be realized, so that the driving performance and the power performance can be improved.

In the embodiment, an actuator (for example, an AC motor) suitable for controlling the rotation speed is used.
Has been described, but if the actuator of the supercharger 11 is a DC motor, rotation speed control cannot be performed. In this case, the bypass valve 14
By controlling the opening degree, the rotation speed control may be performed.

It should be noted that the rotation speed can be controlled by controlling the voltage with a DC motor, as in the case of a PWM, but in the present embodiment, it is assumed that such a rotation speed control mechanism is not provided. ing. That is, the power supply to the DC motor is cut off in the non-supercharged region, and a constant voltage (battery voltage) is applied directly to the DC motor when it is determined that the current is in the supercharged region. At this time, the rotation speed of the DC motor is determined according to the flow rate (load) passing through the supercharger.

A description will be given of another embodiment. A means for detecting the rotational speed of the supercharger is provided, and the turbocharger rotational speed detected by the target supercharging pressure ratio and the turbocharger detected by the detecting means is provided in the supercharging region. The total air flow passing through the turbocharger is calculated by searching a map containing 10. If the total air flow is differentiated as “total air flow 1” and the total air flow calculated in step 6 in FIG. 2 as “total air flow 2”, when the total air flow 1 is larger than the total air flow 2, The target air amount tQa can be obtained by opening and bypassing the bypass passage by the air flow rate. Therefore, a table containing the contents shown in FIG. 14 is retrieved from the value obtained by subtracting the total air flow 2 from the total air flow 1 to calculate the target opening area of the bypass valve. And the bypass valve is driven to this target opening.

The method of calculating the target bypass valve opening in the non-supercharged region is the same as in the first embodiment.

According to this other embodiment, even when the supercharger is driven by an actuator (for example, a DC motor having no rotation speed control mechanism) which is not suitable for performing the rotation speed control, the first operation can be performed. The same effect as the embodiment is obtained.

In the embodiment, the case where the target supercharging pressure ratio is set according to the target air amount has been described. However, the target supercharging pressure itself may be set according to the target air amount.

Although the embodiment has been described with reference to the case of a positive displacement supercharger, a centrifugal supercharger is not excluded.

[Brief description of the drawings]

FIG. 1 is a control system diagram of an embodiment.

FIG. 2 is a flowchart for explaining calculation of three target values.

FIG. 3 is a characteristic diagram of a target air amount.

FIG. 4 is a block diagram for calculating a target air amount.

FIG. 5 is a characteristic diagram of a target driving force.

FIG. 6 is a characteristic diagram of a target gear ratio.

FIG. 7 is a characteristic diagram of a target air amount.

FIG. 8 is a characteristic diagram of a supercharging pressure ratio with respect to a target air amount.

FIG. 9 is a characteristic diagram of a target throttle valve opening.

FIG. 10 is a characteristic diagram of a supercharger.

FIG. 11 is a flowchart for explaining calculation of a target bypass valve opening.

FIG. 12 is a characteristic diagram illustrating a relationship between a bypass valve opening area and a throttle valve opening area.

FIG. 13 is a waveform chart for explaining the operation of the present embodiment.

FIG. 14 is a characteristic diagram of a target bypass valve opening area according to another embodiment.

FIG. 15 is a diagram corresponding to claims of the first invention.

FIG. 16 is a diagram corresponding to claims of the third invention.

[Explanation of symbols]

 Reference Signs List 8 throttle valve 9 DC motor 11 positive displacement supercharger 12 AC motor 14 bypass valve 15 step motor 21 control unit 22 accelerator sensor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B60K 41/06 B60K 41/06 F02D 23/00 F02D 23/00 DFNP 41/02 310 41/02 310D (72) Inventor Isamu Kazama 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Inside Nissan Motor Co., Ltd. (72) Inventor Yasuhito Suzuki 2 Takara-cho, Kanagawa-ku, Yokohama City, Kanagawa Prefecture Nissan Motor Co., Ltd. F-term (reference) 3D041 AA31 AA66 AB01 AC01 AC15 AC19 AD02 AD05 AD10 AD14 AD31 AD51 AE05 AE10 AE31 AF01 3G084 BA03 BA04 BA05 BA07 BA32 DA04 EC05 FA05 FA06 FA07 FA10 FA12 FA18 FA20 FA29 FA32 FA38 3G092 AA01 AA06 AA18 BA01 BA04 BB01 DC03 GA03 DC03 HA01Z HA06X HA06Z HA16X HA17X HA17Z HD05Z HE03Z HE06X HE08Z HF08Z HF12X HF21Z 3G301 HA01 HA04 HA11 JA03 KA06 LA03 L B04 LC04 MA11 MA18 NC02 PA01Z PA09Z PA11Z PA16Z PA17Z PB03Z PB05Z PD02Z PE03Z PE06Z PE08Z PF01Z PF03Z PF07Z PG02Z

Claims (10)

[Claims] 1. A supercharger driven by an actuator of a type suitable for performing rotation speed control, a means capable of adjusting an intake air amount by an actuator, a means for detecting an accelerator operation amount, and an accelerator operation amount Means for calculating a target air amount based on the target air amount; means for setting a target supercharging pressure according to the target air amount; and a target value of the intake air amount adjusting means based on the target air amount and the target supercharging pressure. Means for calculating the target rotation speed of the supercharger based on the target air amount and the target supercharging pressure, and means for giving the target value to the actuator of the intake air amount adjusting means and driving the actuator. And a means for driving an actuator of the supercharger at the target rotational speed. 2. The engine control device according to claim 1, wherein a target supercharging pressure ratio, which is a ratio to a standard pressure, is used instead of the target supercharging pressure. 3. A supercharger driven by an actuator which is not suitable for controlling the rotational speed, a bypass valve capable of adjusting the amount of air flowing through a passage bypassing the supercharger by the actuator, and a suction valve. Means for adjusting the air amount by an actuator, means for detecting an accelerator operation amount, means for calculating a target air amount based on the accelerator operation amount, and means for setting a target supercharging pressure according to the target air amount Means for calculating a target value of the intake air amount adjusting means based on the target air amount and the target supercharging pressure; and a target air amount in a supercharging region based on the target air amount in a non-supercharging region. Means for calculating a target opening of the bypass valve based on the total flow rate of air passing through the supercharger, and driving the actuator of the intake air amount adjusting means by giving the target value to the actuator. That means a control device of an engine, characterized in that it comprises a means for driving giving the target opening in the actuator of the bypass valve. 4. A means for calculating a total air flow rate passing through the supercharger includes means for detecting a rotation speed of the supercharger, and a supercharging pressure ratio when the supercharger is operated in a supercharge region. 4. The engine control device according to claim 3, further comprising: means for calculating a total air flow rate passing through the supercharger from a turbocharger rotation speed detected by the detection means. 5. The engine control device according to claim 3, wherein a target supercharging pressure ratio that is a ratio to a pressure in a standard state is used instead of the target supercharging pressure. 6. The control device for an engine according to claim 2, wherein the actuator of the supercharger is a motor. 7. When the target value of the intake air amount adjusting means is the target opening degree of the throttle valve, the means for calculating the target opening degree of the throttle valve determines the target air amount and the target supercharging pressure ratio. And means for calculating a target air amount when the throttle valve upstream is in a standard state, and means for calculating a target opening of the throttle valve based on the target air amount in a standard state when the throttle valve is upstream. The control device for an engine according to claim 6, wherein 8. The engine control device according to claim 6, wherein the target boost pressure ratio is set to 1 when the target air amount is equal to or less than the maximum air amount in natural intake. 9. A means for calculating a target rotation speed of the supercharger includes: means for calculating a total air flow rate passing through the supercharger based on the target air amount; and a means for calculating the total air flow rate and the supercharging pressure ratio. The engine control device according to claim 2, further comprising means for calculating a target rotational speed of the supercharger by searching a supercharger characteristic map from the engine. 10. The means for calculating the target air amount includes means for calculating a target driving force based on an accelerator operation amount and a vehicle speed, and converting the target driving force into a target gear ratio for a transmission and a target engine torque. The engine control device according to any one of claims 1 to 9, further comprising means for calculating a target air amount based on the target engine torque.