JP2009228586A - Control device of internal combustion engine with motor-driven turbocharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance drivability by suppressing torque reduction as much as possible at the time of restricting a motor operation in a motor-driven turbocharger. <P>SOLUTION: There are provided a first map for setting a target air-fuel ratio of an internal combustion engine when the operational range of the internal combustion engine is in a supercharging range, and a second map for setting a target air-fuel ratio of the internal combustion engine at the time of restricting a turbocharger operation. When it is determined that the operational temperature of the turbocharger is in a predetermined temperature range, the target air-fuel ratio of the internal combustion engine is set by using the second map irrespective of the operational range of the internal combustion engine. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for an internal combustion engine provided with an electric supercharger that performs supercharging according to the operating state of the internal combustion engine.

2. Description of the Related Art Conventionally, a turbocharger has been provided with a compressor that supercharges intake air in an intake passage of an internal combustion engine (engine), and this compressor is operated by the energy of exhaust gas to increase the amount of intake air and improve engine torque (Exhaust turbochargers) are widely used (see, for example, Patent Document 1).
In recent years, various types of electric superchargers or electric compressors in which the compressor is driven by a motor have been proposed in addition to those utilizing the energy of the exhaust gas.

An engine equipped with such a supercharging system using an electric compressor is generally provided with an electronically controlled throttle valve as a throttle valve, and the actuator of this throttle valve and the motor of the electric compressor are integratedly controlled. Yes.
For example, when the accelerator position sensor detects the accelerator depression amount (accelerator opening) of the driver, the electronic control unit (ECU) calculates the intake air amount required for the engine based on the detected accelerator opening information. At the same time, the rotational speed of the compressor and the opening of the throttle valve are calculated so as to meet the required intake air amount. Based on these calculation results, the ECU outputs a control signal to the motor of the electric compressor and the actuator of the throttle valve to control the amount of intake air taken into the engine.

A bypass passage that bypasses the electric compressor is provided upstream of the throttle valve. And when supercharging to the engine is necessary, the electric compressor is operated without using the bypass passage to perform supercharging, and when supercharging to the engine is not necessary (when naturally aspirating or NA), the electric compressor The natural intake from the bypass passage is performed without operating (or idling).
JP 2002-30974 A

Here, FIG. 5 is a diagram showing the target air-fuel ratio characteristics and the operating characteristics of the electric compressor in the supercharging region using the load (accelerator opening) and the engine speed as parameters, and the solid line (line a in FIG. ) Is a line indicating the characteristic of the target air-fuel ratio, and a broken line (line b: 0 boost line) is a line indicating the boundary between the supercharging region and the non-supercharging region, and corresponds to a fully open output during natural intake.
When the operating point obtained from the accelerator opening and the engine speed exceeds the line b (0 boost line), the supercharging region is reached and the compressor operates. That is, in this case, since the required torque cannot be output by natural intake, the compressor is operated to ensure the output torque.

  Further, if the operating point obtained from the accelerator opening and the engine speed is below the line b (0 boost line), it becomes a non-supercharging region (that is, a natural intake region or NA region), and the compressor is It becomes idle driving. That is, in this case, since it is an operating range in which sufficient output torque can be ensured without supercharging, the compressor is in an operating state in which it is not supercharged as idle operation. In this case (in the case of the non-supercharged region), naturally, no supercharging pressure is applied, so that it can be regarded as an engine without a supercharger (naturally-intake engine or NA engine).

  On the other hand, focusing on the air-fuel ratio, when the compressor is operated, that is, at the time of supercharging, when the operating point obtained from the engine speed and the load exceeds the line a in FIG. 5, the air-fuel ratio is made rich (enriched), and the line a If it is lower than, the air-fuel ratio is set to stoichiometric (stoichio or stoichiometric air-fuel ratio). Therefore, when operating at point c in FIG. 5 during supercharging, the air-fuel ratio becomes rich (enriched), whereas when operating at point d, the air-fuel ratio becomes stoichiometric.

  By the way, in the electric supercharger (ESS) as described above, if the motor is continuously operated at a high speed, the bearing temperature for supporting the motor winding and the rotating shaft of the compressor increases, and the durability may be reduced. For this reason, the ECU constantly monitors the temperature of the motor winding and the shaft bearing, and if the temperature exceeds the judgment value, it limits the operation of the motor (the compressor speed is extremely low, that is, the motor is idled). This reduces the temperature of the turbocharger.

  However, when the operation of the motor is restricted, the supercharging pressure is not applied even if the required torque obtained from the accelerator opening of the driver is in the supercharging region, and the state becomes the non-supercharging state. In this case, the engine output is the fully open output (corresponding to the 0 boost line) of the naturally aspirated engine (NA engine), so that the operating point is limited when the operation of the motor is restricted at point c in FIG. Will shift from point c to point c ', and the air-fuel ratio will be set to stoichiometric.

Therefore, when the motor operation is restricted, the supercharging pressure is not applied and the air-fuel ratio is set from rich to stoichiometric, and when the compressor operation is restricted, the output torque is greatly reduced, impairing the acceleration performance. There was a problem.
Patent Document 1 described above discloses a technique in which the lean operation region is changed to a low load side when a turbocharger abnormality is detected. In such a technique, the air-fuel ratio is limited when the operation of the compressor is limited. Was changed to the lean side, and the above-mentioned problems could not be solved.

  The present invention has been devised in view of such a problem, and provides a control device for an internal combustion engine with an electric supercharger that suppresses torque reduction at the time of motor operation restriction as much as possible and improves drivability. The purpose is to provide.

  For this reason, the control device for an internal combustion engine with an electric supercharger according to the present invention includes a motor-driven supercharger that is interposed in an intake passage of the internal combustion engine and pressurizes intake air in the intake passage, and a request for the internal combustion engine A load sensor that detects a load, and a determination unit that determines, based on information from the load sensor, whether the operating region of the internal combustion engine is a supercharging region that supercharges intake air or a non-supercharging region that does not perform supercharging A first map for setting a target air-fuel ratio of the internal combustion engine during normal operation of the supercharger, and a second map for setting a target air-fuel ratio of the internal combustion engine when operation of the supercharger is limited And an air-fuel ratio setting means for detecting the temperature of the supercharger including the motor, and the air-fuel ratio setting means is provided on the basis of information from the temperature sensor. If it is determined that the operating temperature is within a predetermined temperature range, the second map is There are is characterized by setting a target air-fuel ratio of the internal combustion engine (claim 1).

Further, when it is determined that the operating temperature of the supercharger is within a predetermined temperature range, it is preferable to limit the rotation speed of the motor to a low speed or idle rotation (Claim 2).
In addition, a rotation speed sensor for detecting the rotation speed of the internal combustion engine is provided, and the first and second maps are maps for setting the target air-fuel ratio based on the load and the rotation speed. 2 is a rich air-fuel ratio in which a region on a lower load side than the maximum output characteristic line of the non-supercharged internal combustion engine makes the target air-fuel ratio richer than the stoichiometric air-fuel ratio. The area is preferably set (claim 3).

  With this configuration, the second map has a rich effect of suppressing torque reduction because the target air-fuel ratio is set to a rich air-fuel ratio on a predetermined low load side of the maximum output characteristic line of the internal combustion engine.

  According to the control device for an internal combustion engine with an electric supercharger of the present invention, if the operating temperature of the supercharger is within a predetermined temperature range, the target air-fuel ratio is set using the second map, so the supercharger The target air-fuel ratio is set in consideration of the operation limit. Thereby, even when the temperature of the supercharger falls within a predetermined temperature range, an appropriate target air-fuel ratio can be set, and a decrease in torque associated with the operation restriction of the supercharger can be suppressed. Therefore, drivability is improved.

Hereinafter, a control device for an internal combustion engine with an electric supercharger according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the overall configuration thereof.
In FIG. 1, 9 indicates an engine mounted on the vehicle. An intake passage 1 is connected to the engine 9, and an electric compressor (electric supercharger) 3 and an electronically controlled throttle valve (throttle valve) 4 are interposed in the intake passage 1. An air cleaner 8 for removing dust in the air sucked into the engine 9 is provided upstream of the electric compressor 3.

  In addition to the above-described electric compressor 3 and the like, an ECU (electronic control unit) 20 as control means for controlling the operation of the electric compressor 3 and the throttle valve 4 and the driving power of the electric compressor 3 are provided around the engine 9. A battery 10 to be supplied, an accelerator position sensor 7 as a load sensor for detecting the depression amount of the accelerator pedal 6 by the driver, an engine speed sensor (engine speed detecting means) 13 for detecting the speed of the engine 9, and an intake passage An intake pressure sensor (referred to as an intake manifold pressure sensor or a manifold pressure sensor) 12 for detecting the actual intake pressure is provided.

  Among these, the accelerator position sensor 7 is interposed in the vicinity of the accelerator pedal 6, detects the amount of depression of the driver's accelerator pedal 6 (accelerator opening information), and outputs this detection information to the ECU 20 described later. It has become. The accelerator opening information detected by the accelerator position sensor 7 is treated as a parameter representing the output requested by the driver from the vehicle. That is, it is determined whether or not the driver is accelerating the vehicle (acceleration determination) from the time change amount (time increase amount) of the accelerator opening information. The accelerator opening information is detected as one of the parameters indicating the load state of the engine 9, and in particular, in this embodiment, the accelerator opening is used as the engine load.

  In this embodiment, a throttle position sensor 5 that detects the opening of the throttle valve 4 is provided. The valve opening information of the throttle valve 4 detected by the throttle position sensor 5 is output to the ECU 20. Further, the engine speed sensor 13 detects information on the number of revolutions of the engine 9, and this speed information is outputted to the ECU 20.

  The opening degree of the throttle valve 4 provided in the intake passage 1 of the engine 9 is controlled based on a control signal from the ECU 20, thereby adjusting the amount of intake air taken into the engine 9. It has become so. In addition, the intake air amount sucked into the engine 9 is calculated based on accelerator opening information detected by the accelerator position sensor 7 in the ECU 20.

  The electric compressor 3 is provided upstream of the throttle valve 4 so that intake air can be supercharged as necessary. Further, whether or not supercharging is necessary is determined by a map (see FIG. 2) stored in the ECU 20. Specifically, the compressor 3 is operated depending on whether the current operation state determined by the accelerator opening and the engine speed is in a supercharging region or a non-supercharging region (NA region) set in advance on the map. Or not is determined.

Further, the electric compressor 3 includes an electric motor (electric motor) 31 and a compressor main body 32, and the compressor main body 32 rotates integrally with the motor 31 being driven to rotate. The driving power of the electric motor 31 is supplied from the battery 10 via the supercharger driver 11.
When the ECU 20 determines that the engine operating state is in the supercharging region, the ECU 20 obtains a required supercharging pressure based on the accelerator opening, and the electric motor 31 of the electric motor 31 through the supercharger driver 11 so as to obtain the required supercharging pressure. The operating rotational speed is controlled. The supercharger driver 11 controls the rotational speed of the electric motor 31 by controlling the current from the battery 10. Further, the rotational speed of the motor 31 is feedback controlled based on information from an intake pressure sensor 12 described later.

The motor 31 is provided with a motor temperature sensor 33 that detects the temperature of the motor. In this embodiment, the motor temperature sensor 31 is attached to a housing (not shown) of the motor 31 and is configured to detect the housing temperature of the motor 31. The temperature information detected by the temperature sensor 31 is output to the ECU 20.
In place of the temperature sensor 33 as described above, means for detecting or estimating the temperature of a place where the motor 31 is likely to become hot during continuous operation, such as a winding of the motor 31 and a shaft bearing (both not shown), are provided. Also good. Further, the overall operating temperature of the compressor (supercharger) 3 may be detected or estimated.

  Further, a bypass passage 14 for bypassing the electric compressor 3 is provided upstream of the throttle valve 4 in parallel with the electric compressor 3, and the reed valve 2 is interposed on the bypass passage 14. Thus, when the engine 9 needs to be supercharged, the intake air is supercharged via the electric compressor 3 described above, while when the engine 9 does not need to be supercharged (that is, during natural intake), the electric compressor Natural intake is performed through the reed valve 2 without the operation of 3. The reed valve 2 is configured as a one-way valve that allows only the flow of intake air to the engine 9 and prohibits the reverse flow.

  When supercharging is not required (during natural intake), the compressor 3 is not completely stopped, but is maintained in an idle operation state at a predetermined rotation speed (for example, about 5000 rpm). The predetermined number of revolutions in the idling state is set as high as possible in a range where no boost pressure is generated (0 boost), and intake air is supplied to the engine 9 by the action of the negative pressure generated when the piston descends. Then, by performing idle operation without stopping the motor 31 during operation in the non-supercharging region, the rotational speed of the compressor main body 32 is quickly increased when the engine operating state shifts to the supercharging region due to depression of the accelerator. Therefore, the delay in the rise of the supercharging pressure (turbo lag) can be greatly reduced.

  An intake pressure sensor (intake manifold pressure sensor) 12 is a sensor that detects an intake pressure in the vicinity of a surge tank (not shown) in the intake passage 1 or an intake manifold, and is a sensor that detects the pressure of the intake air actually supplied to the engine 9. is there. Therefore, since the supercharging pressure (boost pressure) of the supercharged intake air is detected when the electric compressor 3 is operating, the intake pressure sensor 12 is referred to as a supercharging pressure sensor (boost pressure sensor). You can also.

Further, the ECU 20 performs feedback control on the supercharging pressure of the electric compressor 3 based on the supercharging pressure detected by the intake pressure 12.
Next, the configuration of the main part of the present apparatus will be described. Detection information of various sensors such as the throttle position sensor 5, the accelerator position sensor 7, the intake pressure sensor 12, the engine speed sensor 13 and the motor temperature sensor 33 described above is sent to the ECU 20. It is input and processed.

The ECU 20 includes a determination unit (determination unit) 21, a calculation unit (air-fuel ratio setting unit) 22, a motor control unit (motor operation control unit) 23, and a throttle valve control unit (throttle valve operation control unit) 24. It is configured.
Among these, the determination part 21 is based on the information from the accelerator position sensor 7 as a load sensor, and the information from the engine speed sensor 13, and the operating state of the engine 9 is the supercharging area which supercharges intake air, or supercharging. A non-supercharging region that is not to be determined is determined, and is provided as a map having the accelerator opening and the engine speed as parameters as shown in FIG.

If the operating point obtained from the accelerator opening and the engine speed is above the 0 boost line (high load side) shown in the map of FIG. 2, the motor 31 is driven to operate the compressor 3. It has become. That is, in this case, since the required torque cannot be output by natural intake, the compressor is operated to ensure the output torque.
Further, if the operating point obtained from the accelerator opening and the engine speed is below the 0 boost line (low load side), the natural intake area (NA area) is entered, and the compressor is in idle operation. That is, in this case, since it is an operating range in which sufficient output torque can be ensured without supercharging, the compressor is in an operating state in which it is not supercharged as idle operation. In this case (in the case of the non-supercharged region), naturally, no supercharging pressure is applied, so that it can be regarded as an engine without a supercharger (naturally-intake engine or NA engine).

  The determination unit 21 determines whether or not the operation of the motor 31 can be restricted based on the motor temperature Tm obtained from the motor temperature sensor 33. Here, the determination unit 21 stores in advance a first predetermined value T1 and a second predetermined value T2 (> T1) as threshold values relating to the motor temperature Tm, and either Tm <T1 or Tm ≧ T2. When the above condition is satisfied, the rotation of the motor 31 is limited to protect the motor 31 even if the operating state of the engine 13 is in the supercharging region.

Note that T1 is a temperature lower than 0 ° C., for example, and is set assuming an operation at an extremely low temperature. It is conceivable that the motor 31 is frozen and does not operate at such a low temperature, and if a load is applied forcibly, the motor 31 may be damaged. Therefore, the motor 31 is not operated in such a range below the threshold T1 on the low temperature side.
Further, T2 is a threshold value on the high temperature side, and is set to suppress the seizure of the bearing of the motor 31 and the excessive temperature rise of the motor winding. Under such a high temperature, the motor 31 is idled to prevent the motor 31 from being damaged.

  The calculation unit 22 calculates the target boost pressure Pt, the required intake air amount Qt, and the target rotational speed Nt of the motor 9 based on information from the accelerator position sensor 7 as a load sensor. More specifically, when the determination unit 21 determines that the engine 9 is in the supercharging region, the required intake air amount Qt is calculated based on a supercharging map (not shown), and the target supercharging is calculated from the required intake air amount Qt. The pressure Pt is obtained. Further, when the target boost pressure Pt is obtained, the target rotational speed Nt of the motor 31 is calculated based on the target boost pressure Pt. Further, feedback information from the intake pressure sensor 12 is added to the target rotational speed Nt. The setting method and calculation method of the required intake air amount Qt, the target boost pressure Pt, and the target rotation speed Nt are not particularly limited, and can be determined by various known methods.

  In addition to this, the calculation unit 22 has a function of setting a target air-fuel ratio (A / F) for the engine 9. Here, the calculation unit 22 sets the target air-fuel ratio based on the load (accelerator opening) and the engine speed. When the target air-fuel ratio is set by the calculation unit 22, the set target air-fuel ratio is set. The drive time of an injector (not shown) is set so that the air-fuel ratio is obtained.

  Hereinafter, the setting of the target air-fuel ratio will be described in detail. The calculation unit 22 is provided with two maps 201 and 202 as shown in FIGS. The target air-fuel ratio is set using one of these maps 201 and 202 according to the state. Of the two maps, a map 201 shown in FIG. 3A is a map (first map) 201 for setting a target air-fuel ratio during normal operation (when the operation of the compressor 3 is permitted). The map shown in b) is a map (second map) 202 for setting the target air-fuel ratio when the compressor 3 is at a high temperature (when the operation of the compressor 3 is limited).

Here, the characteristics of these maps 201 and 202 will be described. The operation permission map 201 of the compressor 3 shown in FIG. 3A reliably guarantees the operation of the compressor 3 (or the motor 31) by the temperature of the motor 31. It is a map for normal operation applied when it exists in the temperature range which can be set, ie, when motor temperature Tm is more than T1 and less than T2.
In this map 201, a characteristic line a that divides the rich region and the stoichiometric region is set on the higher load side than the 0 boost line in substantially the entire rotational region excluding a partial region on the high rotational side of the engine speed. When the vehicle is operating above the line a, that is, at a higher load side than the line a (see, for example, the point c), the target air-fuel ratio is set to a rich air-fuel ratio. When the vehicle is operating below the line a, that is, at a lower load side than the line a (see, for example, the point d), the target air-fuel ratio is set to stoichiometric.

On the other hand, the operation restriction map 202 of the compressor 3 shown in FIG. 3B is used when the temperature of the supercharger is equal to or higher than T2 as described above, that is, when the operation of the compressor 3 is restricted to idle operation. In this map, since the supercharging pressure is not applied when this map is used, the target air-fuel ratio is not set in a higher load region than the 0 boost line shown in the figure.
As shown in the drawing, the target air-fuel ratio is set to be rich within a predetermined range on the low load side of the 0 boost line, and the target air-fuel ratio is set to stoichiometric in a lower load range than this predetermined range. ing.

As described above, the determination unit 21 determines whether the load, the rotational speed, and the operating state of the engine 9 are in the supercharged region or the non-supercharged region, and the calculation unit 22 determines that the temperature Tm of the supercharger 3 is the predetermined temperature T1. The two maps 201 and 202 are switched based on whether the temperature is less than or less than the predetermined temperature T2, and the target air-fuel ratio is set according to the engine operating state.
This is because when the temperature is in the predetermined temperature range (Tm <T1 or Tm ≧ T2) as described above, the operation of the motor 31 is limited, and the output characteristics of the engine are the same as those of a naturally aspirated engine. Here, when the temperature of the motor 31 becomes equal to or higher than the predetermined temperature T2 during operation at the point c in FIG. 3A, the operation of the motor 31 is limited to idle operation or the like, and the boost pressure against the intake air of the engine 9 is increased. Becomes substantially zero. As a result, the operating point at point c shifts to the operating point at point c ′ on the 0 boost line. In this first map 201, however, the target air-fuel ratio is set to stoichiometric at the 0 boost line. If the target air-fuel ratio is simply set using the first map 201, the air-fuel ratio becomes leaner than the target air-fuel ratio (enrich) during the natural intake operation, resulting in a relatively low torque and poor acceleration. become.

Therefore, in the present apparatus, when the temperature of the motor 31 is in the temperature range subject to the operation restriction, the second map 202 is basically selected, and the target air-fuel ratio is set using the second map. It has become.
When the target boost pressure Pt, the required intake air amount Qt, the target rotational speed Nt of the motor 31 and the target air-fuel ratio of the engine 9 are obtained in the calculation unit 22 as described above, the motor control unit 23 of the ECU 20 calculates the above-described calculation. A current value for the motor 31 is obtained from the target rotational speed Nt calculated by the unit 22, and a control signal for the driver 11 is output so that this current value is obtained. And the operating rotational speed of the compressor 3 is controlled by such control.

Further, the throttle valve control unit 24 sets the throttle opening of the throttle valve 4 according to the depression amount of the accelerator pedal of the driver, and an actuator (not shown) of the throttle valve 4 so as to become the set throttle opening. The operation of is controlled.
Further, the ECU 20 obtains an injector drive pulse (not shown) from the intake air flow rate and the target air-fuel ratio, and outputs an operation control signal for the injector so as to execute fuel injection with this drive pulse.

Since the control device for an internal combustion engine with an electric supercharger according to an embodiment of the present invention is configured as described above, its operation will be described below with reference to the flowchart of FIG.
First, in step S1, the motor temperature Tm is compared with the predetermined temperatures T1 and T2, and it is determined whether or not T1 ≦ Tm <T2. If T1 ≦ Tm <T2, the process proceeds from step S1 to step S2, the operation permission map (first map) 201 of the compressor 3 is selected as the target air-fuel ratio map, and the target sky is used using this map 201. Set the fuel ratio.

  Further, if T1 ≦ Tm <T2 is not satisfied in step S1, that is, if the predetermined temperature range is reached, the process proceeds to step S3, where the operation restriction map of the compressor 3 (second map) is used as the target air-fuel ratio map. ) 202 is selected, and the target air-fuel ratio is set using this map 202. That is, in this case, the second map 202 is selected instead of the first map 201 as the air-fuel ratio setting map.

Thereafter, normal control of the compressor 3 and air-fuel ratio control are executed, and the engine 9 is operated.
Thus, according to the present apparatus, when the motor temperature is in the predetermined temperature range (Tm <T1, or Tm ≧ T2), the second map 202 for restricting the operation of the compressor is applied as the target air-fuel ratio. . In the second map 202, the target air-fuel ratio is set to be enriched in a predetermined region below the 0 boost line including the 0 boost line, so that the operation of the motor 31 is limited and the boost pressure is sufficiently increased. Even under such conditions, at least the air-fuel ratio can be made richer than the stoichiometric rich air-fuel ratio, and the reduction in torque due to the operation restriction of the turbocharger 3 can be suppressed or offset by enriching the air-fuel ratio. can do. Therefore, there is an advantage that a decrease in drivability when the operation of the motor 31 is restricted can be suppressed as much as possible.

In addition, this device can be realized with a simple configuration in which only the control logic is changed without adding new parts or devices to the control device for the conventional electric supercharger, which may increase the cost. Absent.
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the type of the electric compressor 3 is not particularly limited as long as the electric compressor 3 compresses and supercharges intake air by the motor 31.

1 is a schematic diagram illustrating an overall configuration of a control device for an internal combustion engine with an electric supercharger according to an embodiment of the present invention. It is a figure for demonstrating the supercharging characteristic of the control apparatus of the internal combustion engine with an electric supercharger concerning one Embodiment of this invention. 1 is a diagram showing a target air-fuel ratio characteristic in a control device for an internal combustion engine with an electric supercharger according to an embodiment of the present invention, wherein (a) is a diagram showing a target air-fuel ratio characteristic when the operation of the supercharger is permitted; (B) is a figure which shows the target air fuel ratio characteristic at the time of the operation | movement limitation of a supercharger. It is a figure for demonstrating a supercharging characteristic. It is a flowchart for demonstrating an effect | action of the control apparatus of the internal combustion engine with an electric supercharger concerning one Embodiment of this invention. It is a figure which shows the target air fuel ratio characteristic of the internal combustion engine according to the operating state of the electric supercharger devised in the creation process of this invention, Comprising: It is a figure which shows a target air fuel ratio characteristic.

Explanation of symbols

1 Intake passage 2 Reed valve 3 Electric compressor (supercharger)
4 Throttle valve (electronically controlled throttle valve)
5 Throttle position sensor 6 Accelerator pedal 7 Accelerator opening sensor or APS (load sensor) constituting actual intake air amount detecting means
9 Engine (Internal combustion engine)
12 Intake Pressure Sensor Constructing Actual Intake Amount Detection Unit 13 Engine Speed Sensor 21 Determination Unit (Determination Unit)
22 Calculation unit (air-fuel ratio setting means)
23 Motor controller (motor operation control means)
24 Throttle valve control unit (Throttle valve operation control means)
31 Motor 32 Compressor body 33 Motor temperature sensor (temperature sensor)
201 Supercharger operation permission map (first map)
202 Supercharger operation restriction map (second map)

Claims (3)

A motor-driven supercharger interposed in the intake passage of the internal combustion engine and pressurizing the intake air in the intake passage;
A load sensor for detecting a required load on the internal combustion engine;
Determination means for determining whether the operating region of the internal combustion engine is a supercharging region in which intake air is supercharged or a non-supercharging region in which supercharging is not performed based on information from the load sensor;
A first map for setting a target air-fuel ratio of the internal combustion engine during normal operation of the supercharger, and a second map for setting a target air-fuel ratio of the internal combustion engine when operation of the supercharger is limited Provided air-fuel ratio setting means;
A temperature sensor for detecting the temperature of the supercharger including the motor;
When the air-fuel ratio setting means determines that the operating temperature of the supercharger is within a predetermined temperature range based on information from the temperature sensor, the target air-fuel ratio of the internal combustion engine is determined using the second map. A control device for an internal combustion engine with an electric supercharger, wherein the control device is set. The internal combustion engine with an electric supercharger according to claim 1, wherein when the operating temperature of the supercharger is determined to be within a predetermined temperature range, the rotational speed of the motor is limited to a low speed or an idle speed. Control device. A rotational speed sensor for detecting the rotational speed of the internal combustion engine;
The first and second maps are maps that set the target air-fuel ratio based on the load and the rotational speed,
The second map shows a rich air-fuel ratio in which the target air-fuel ratio is richer than the stoichiometric air-fuel ratio in a predetermined low load side area from the maximum output characteristic line of the non-supercharged internal combustion engine. 3. The intake control apparatus for an internal combustion engine according to claim 1, wherein the intake control apparatus is set in an air-fuel ratio region.