JP2005188483A - Control device for engine with electric supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure superior electric power-saving performance and excellent acceleration response performance causing no response delay to accelerator operation of a driver, in a control device of an engine with a motor-driven supercharger. <P>SOLUTION: A target supercharging pressure setting means 21 sets target supercharging pressure of the motor-driven supercharger 3 on the basis of an engine load detected by an engine load detecting means 7 and an engine speed detected by an engine speed detecting means 13. A control means 20 substantially fully opens an electronic control throttle valve 4 by driving an electric motor 31 so as to become the target supercharging pressure when the engine load detected by the engine load detecting means 7 exceeds a preset first supercharging area determining load, by determining that a vehicle is an acceleration state by an acceleration state determining means 23. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control device for an engine with an electric supercharger that performs supercharging according to the running state of a vehicle.

Conventionally, the engine is supercharged as required by an electric compressor (electric supercharger) driven only by an electric motor that is not affected by exhaust pressure, crank rotation, etc., and a throttle valve is provided by an electronically controlled throttle valve (ETV). An intake system that controls the intake air to the engine has been developed.
In such an intake system, the accelerator position sensor (APS) detects the accelerator opening corresponding to the accelerator depression amount of the driver, and the engine position information is detected based on the accelerator opening information detected by the electronic control unit (ECU). The amount of intake air to be drawn into the engine is calculated, and the operation of the electric compressor and the opening of the electronically controlled throttle valve are controlled to match the required amount of intake air, thereby controlling the amount of intake air drawn into the engine It has come to be. Of course, from the viewpoint of operation feeling, the opening / closing of the electronically controlled throttle valve is basically controlled in accordance with the accelerator opening.

  In addition, a bypass passage that bypasses the electric compressor is provided in parallel with the electric compressor upstream of the electronically controlled throttle valve. When the engine needs to be supercharged, the electric compressor is operated to supercharge the engine. When supercharging is not necessary (at the time of natural intake), natural intake from the bypass passage can be performed without operating the electric compressor.

  By the way, generally, in such a conventional intake system, as shown in FIG. 6, the intake inertia is small when the engine speed is low, such as during high-load low-speed traveling (hill climbing / loading load). In addition, since the intake valve opening time is longer than when the engine speed is high, the air once taken into the cylinder during the intake stroke is returned to the intake port during the compression stroke, or leaks to the crankcase through the piston gap. There is a lot of air leakage. Therefore, even if the electronically controlled throttle valve is opened to some extent, the amount of air that can be sucked is unlikely to increase. Performance may not be obtained.

  On the other hand, in such a state where the engine intake capacity is low, it is conceivable to perform supercharging by operating the electric compressor so as to supplement the engine intake capacity. However, at the time of supercharging by the electric compressor, the electronically controlled throttle valve becomes a physical resistance on the intake passage. Although this resistance causes intake pressure loss, the smaller the opening of the electronically controlled throttle valve, the greater the resistance, and the greater the intake pressure loss, limiting the amount of intake to the engine. As a result, a sufficient supercharging effect may not be obtained, for example, when an acceleration operation is performed at a low engine speed.

  For example, Patent Document 1 discloses a control device for an internal combustion engine in which an electric pump is installed as a supercharger for intake air. A target intake air amount tQa of the internal combustion engine calculated based on inputs from various sensors including an accelerator operation amount is provided. Describes a configuration in which the throttle valve is held in the vicinity of the fully open position when it is an amount that requires supercharging. According to this technology, by holding the throttle valve in the vicinity of the fully open state when air is inhaled by the supercharger, friction loss due to the throttle valve can be reduced, and the maximum output can be increased while saving fuel consumption. It has become.

  Further, Patent Document 2 is provided in a bypass passage that bypasses the electric supercharger when a required load change due to acceleration operation of the accelerator pedal is smaller than a reference value (that is, in a steady operation state). With the bypass valve open to some extent, the rotational speed of the electric supercharger is controlled so that the target boost pressure can be obtained, and when the required load change exceeds the reference value (that is, rapid acceleration or rapid deceleration is required) When it is determined that there is a technology, a technique for reducing the opening of the bypass valve and controlling the rotational speed of the electric supercharger so as to achieve the target supercharging pressure is disclosed. According to this technology, the boost pressure can be quickly increased or decreased by increasing / decreasing the bypass valve opening, and good engine torque response performance can be obtained regardless of the response delay of the rotation speed of the electric supercharger. be able to.

Regarding the setting of the intake air amount by the electric supercharger, Patent Document 3 describes a configuration for calculating a target supercharging pressure to be supercharged by the turbocharger from data on the engine speed and the accelerator opening. Yes.
JP 2002-364571 A JP 2001-280145 A JP-A-8-121183

  However, in Patent Document 1 described above, the target boost pressure tPc is calculated from the target intake air amount tQa based on arbitrarily set table data, and supercharging is required according to the magnitude of the target boost pressure tPc. Whether or not is determined. That is, if the target intake air amount tQa for starting supercharging is set large, it is difficult to determine that the internal combustion engine needs supercharging (that is, it is difficult to start supercharging). As a result, sufficient acceleration response performance may not be obtained. On the other hand, if the target intake air amount tQa for starting supercharging is set small, the operating range due to super intake increases, and the supercharger operates frequently, so that the power consumption of the supercharger is reduced. This may increase the battery charge amount.

Moreover, also in the above-mentioned patent document 2, since the electric supercharger is always operated by controlling the rotation speed, the supercharger is operating even when supercharging to the engine is not necessary. As a result, there is a problem that the power consumption of the electric supercharger increases and the battery charge amount may decrease.
The present invention has been devised in view of such problems, and is capable of ensuring a good acceleration response performance without delay in response to the driver's accelerator operation, and having an excellent power saving performance. It is an object of the present invention to provide a control device for an attached engine.

  In order to achieve the above object, an engine control apparatus with an electric supercharger according to the present invention (Claim 1) is provided in an intake system of an engine mounted on a vehicle and driven by an electric motor to supercharge intake air. An electronic control throttle valve that is provided in the intake system of the engine and can be controlled independently of a driver's accelerator operation; an engine speed detecting means for detecting the engine speed; and the engine Engine load detection means for detecting the load of the vehicle, acceleration state determination means for determining the acceleration state of the vehicle, engine load detected by the engine load detection means, and engine rotation speed detected by the engine rotation speed detection means The target supercharging pressure setting means for setting the target supercharging pressure of the electric supercharger based on the above and the acceleration state determination means that the vehicle is in an acceleration state And when the engine load detected by the engine load detecting means exceeds a preset first supercharging region determination load, the electric motor is driven to achieve the target supercharging pressure and the electronic control is performed. And a control means for substantially fully opening the throttle valve.

Preferably, the engine load detecting means is an accelerator operation amount detecting means for detecting an accelerator operation amount by a driver as a parameter corresponding to the engine load state.
Further, as the information on the engine load, an opening degree of the electronically controlled throttle valve or an intake air amount to the engine may be used.

In addition, it is preferable that the acceleration state determination means determines the acceleration state of the vehicle based on an accelerator operation amount by a driver.
Further, the control means determines in advance that the vehicle is not in an acceleration state by the acceleration state determination means, and the engine load is preliminarily set to a value higher than the first supercharging region determination load by the engine load detection means. When it is detected that the set second supercharging region determination load is exceeded, the electric motor is driven so as to be the target supercharging pressure, and the electronically controlled throttle valve is fully opened or substantially fully opened. Preferred (claim 4).

  The engine further includes a supercharging region setting means for setting a supercharging region and a natural intake region of the engine based on the engine load and the engine speed, and the electric motor is set by the supercharging region setting unit. The electric supercharger is driven in an engine supercharging region, and when the acceleration state determination means determines that the vehicle is in an acceleration state, the electric motor is driven based on the setting of the supercharging region setting means. (Claim 5).

Further, it is preferable that the control means drives the electric motor to be the target supercharging pressure by feedback control.
The first supercharging area determination load and / or the second supercharging area determination load may be set as a boundary value between the supercharging area and the natural intake area in the supercharging area setting means. Preferred (claim 7).

  According to the control device for an engine with an electric supercharger of the present invention (Claim 1), when an engine load exceeding the first supercharging region determination load is detected in the acceleration state, the electric motor of the supercharger is driven. Thus, the electronically controlled throttle valve is controlled to be fully opened, so that the response performance of the boost pressure increase during vehicle acceleration can be improved. In addition, when the engine load is equal to or lower than the first supercharging determination load, the motor of the supercharger is not driven. Therefore, the supercharger is not operated too frequently, the proper operation frequency is maintained, and the supercharger is driven. Such power saving can be achieved.

Further, according to the control device for an engine with an electric supercharger of the present invention (Claim 2), the accelerator operation amount by the driver is a parameter corresponding to the state of the engine load, so that the engine load is properly grasped. be able to.
According to the control device for an engine with an electric supercharger of the present invention (Claim 3), since the determination of the acceleration state of the vehicle is based on the accelerator operation amount by the driver, the determination is based on the driver's acceleration intention. It is possible to achieve good control of feeling.

  Further, according to the control device for an engine with an electric supercharger according to the present invention (Claim 4), in the normal operation state, the response performance of the boost pressure rise with respect to the engine load can be improved, and the supercharger is driven. Such power saving can be achieved. Further, in the acceleration state, the supercharger can be driven with a smaller engine load than in the normal operation state, so that better response performance can be obtained.

Further, according to the control device for an engine with an electric supercharger according to the present invention (Claims 5 and 7), the supercharging region can be determined based on the accelerator operation amount that can directly reflect the driver's required torque. The reliability of supercharging control can be improved.
Further, according to the control device for an engine with an electric supercharger of the present invention (Claim 6), the actual supercharging pressure can be quickly brought close to the target supercharging pressure, and the acceleration response can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 6 show a control device for an engine with an electric supercharger as an embodiment of the present invention. FIG. 1 is a schematic diagram showing the overall configuration, and FIG. 2 shows an electric compressor according to this device. FIG. 3 is a map showing the throttle characteristic at the time of low engine rotation, (a) is a throttle characteristic chart during normal operation, (b) is a throttle characteristic chart during acceleration, and FIG. FIG. 5 is a characteristic map for determining whether or not to perform supercharging in this apparatus, (a) is a characteristic map during normal operation, (b) is a characteristic map during acceleration, and FIG. 5 is a supercharging control in this apparatus. FIG. 6 is a map for illustrating the throttle characteristics at the time of engine low rotation in the conventional control apparatus for an engine with an electric supercharger.

  As shown in FIG. 1, the control device 1 for an engine with an electric supercharger 1 of the present embodiment is an electric compressor (electric supercharger) provided on an intake passage to the engine 9 in a vehicle including the engine 9. 3 and an electronically controlled throttle valve (ETV) 4, an ECU (electronic control unit) 20 as a control means for controlling these operations, a battery 10 for supplying driving power to the electric compressor 3, and an accelerator pedal 6 by the driver An accelerator position sensor (accelerator operation amount detection means, engine load detection means) 7 for detecting the stepping operation amount of the engine, an engine speed sensor (engine speed detection means) 13 for detecting the rotation speed of the engine 9, and the electric compressor 3 And a supercharging pressure sensor 12 for detecting the supercharging pressure of the intake air supercharged by (i.e., the intake pressure in the intake pipe).

  The accelerator position sensor 7 detects accelerator opening information corresponding to the amount of depression of the accelerator pedal 6 by the driver. The accelerator opening information detected by the accelerator position sensor 7 is handled 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 position sensor 7 detects the accelerator opening information as one of parameters corresponding to the load state of the engine 9.

  In this embodiment, a throttle position sensor 5 for detecting the opening degree of the electronically controlled throttle valve 4 is provided. The throttle position sensor 5 detects throttle valve opening information of the electronically controlled throttle valve 4. Therefore, the throttle valve opening information detected here may be a parameter corresponding to the load state of the engine 9.

The engine speed sensor 13 is configured to detect engine speed information.
The electronically controlled throttle valve 4 provided on the intake passage of the engine 9 is adjusted in opening degree by an ECU 20 to be described later to adjust the intake air amount and supercharging pressure taken into the engine 9. The intake air amount and supercharging pressure sucked into the engine 9 are calculated based on accelerator opening information detected by the accelerator position sensor 7 in the ECU 20 described later. At this time, the ECU 20 can also control the opening degree of the electronically controlled throttle valve 4 independently of the driver's accelerator operation.

  The electric compressor 3 is provided upstream of the electronically controlled throttle valve 4 so that the intake air can be supercharged when the engine 9 needs to be supercharged. The electric compressor 3 includes an electric motor (electric motor) 31, and driving power of the electric motor 31 is supplied from the battery 10 via the supercharger driver 11. Then, the ECU 20 to be described later controls the operating rotational speed of the electric motor 31 through the supercharger driver 11 so that supercharging can be performed while adjusting the supercharging pressure of the intake air. The supercharger driver 11 controls the rotation speed of the electric motor 31 by controlling the voltage of the battery 10.

In the present embodiment, as shown in FIG. 2, the electric compressor 3 is a centrifugal compressor type supercharger that performs supercharging by rotating a turbine wheel 32 by an electric motor 31.
Further, a bypass passage 14 for bypassing the electric compressor 3 is provided upstream of the electronic control throttle valve 4 in parallel with the electric compressor 3, and the reed valve 2 is provided on the bypass passage 14. As a result, when the engine 9 needs to be supercharged, the above-described electric compressor 3 operates to perform supercharging, while when the engine 9 does not need supercharging (that is, during natural intake), the electric compressor 3 Without being operated, natural intake is performed through the reed valve 2. An air cleaner 8 is provided upstream of the electric compressor 3 and the reed valve 2, whereby dust in the air sucked into the engine 9 is removed.

  The supercharging pressure sensor 12 can detect the supercharging pressure of the intake air supercharged by the electric compressor 3. The ECU 20 can perform feedback control of the supercharging pressure by the electric compressor 3 in accordance with the supercharging pressure detected here. In the present embodiment, the supercharging pressure sensor 12 is provided on the intake side of the engine 9 to detect the air pressure in the intake pipe.

  Detection information of various sensors such as the throttle position sensor 5, the accelerator position sensor 7, the supercharging pressure sensor 12, and the engine speed sensor 13 described above is input to the ECU 20 for calculation processing. The ECU 20 includes a target intake pressure setting unit (target supercharging pressure setting unit) 21, a supercharging region setting unit (supercharging region setting unit) 22, and an acceleration state determination unit (acceleration state determination unit) 23. It is configured.

  The acceleration state determination unit 23 determines the acceleration state of the vehicle from the degree of change in the operation amount of the accelerator pedal 6 based on the accelerator operation amount by the driver. That is, it is determined from the time change amount (time increase amount) of the accelerator opening information detected by the accelerator position sensor 7 whether or not the driver is going to accelerate the vehicle. Specifically, a change amount ΔAPS per unit time (or unit cycle) of the accelerator opening APS calculated from the accelerator opening information is calculated, and the change amount is larger than a preset acceleration determination threshold K. It is determined whether or not.

If ΔAPS> K, it is determined that the driver is accelerating the vehicle, and “is in an accelerated state”. If ΔAPS ≦ K, the driver is not trying to accelerate the vehicle. And “determined to be in a normal operation state”.
Based on the accelerator opening APS detected by the accelerator position sensor 7 and the engine speed Ne detected by the engine speed sensor 13, the supercharge area setting unit 22 determines whether the intake control is in the supercharge area. It is determined whether the engine is in the intake region (NA region) (that is, whether or not the engine 9 needs to be supercharged), and control corresponding to each region is set.

  Specifically, based on the maps shown in FIGS. 4 (a) and 4 (b) stored in advance by the supercharging area setting unit 22, the supercharging area and the natural intake area are determined according to the operating state of the engine 9. Is determined. First, when it is determined by the acceleration state determination unit 23 that “it is in a normal operation state”, the setting based on the map shown in FIG. In this map, an accelerator opening threshold value a1 (second supercharging region determination load) that is a boundary (determination condition) between the supercharging region and the natural intake region is given as a value that varies in accordance with the engine speed Ne. It has been. When the accelerator opening APS is larger than the threshold value a1 at a certain engine speed Ne, it is determined that the engine 9 is in a supercharging region where supercharging is required, and the accelerator opening APS is set to the threshold value. In the case of a1 or less, it is determined as a “natural intake area” in which supercharging is not necessary.

  The threshold value a1 is set smaller as the engine speed Ne is smaller. Accordingly, the engine load (accelerator opening) is set to a “supercharging region” from a relatively small engine load (accelerator opening) when the engine 9 is at a low speed, such as at the start, and the engine load (accelerator opening) is relatively large when the engine 9 is at a high speed. The “natural intake area” is set up to the area. Here, the reduction rate of the threshold value a1 of the set accelerator opening APS is set to be larger as the engine speed Ne is smaller. This is because not only the intake air amount to the engine decreases as the engine speed Ne decreases, but also the intake inertia effect to the engine decreases, so that the “supercharging region” from the region where the engine load (accelerator opening) is smaller. It is because it is preferable to set to. On the other hand, when the engine speed Ne increases, the intake air amount increases with respect to the accelerator opening increase amount. Further, the intake air inertia effect can be expected to further increase the intake air amount. The increase rate of the threshold value a1 is reduced.

  If the acceleration state determination unit 23 determines that the state is “acceleration state”, the setting based on the map shown in FIG. 4B is made. In this map, engine threshold value b1 (first supercharging region determination load) serving as a boundary (determination condition) between the supercharging region and the natural intake region is always smaller than threshold value a1. It is given as a value that fluctuates according to the rotational speed. That is, when it is determined that the state is “accelerated state”, the “supercharging region” and “natural intake” are set based on the threshold value b1 that is smaller than the case where it is determined that “normally operated state” (threshold value a1). It is set so that it can be determined as “range”. Here, the characteristic curve of the threshold value b1 during acceleration is set by shifting the characteristic curve of the threshold value a1 during normal operation to the lower engine load.

Therefore, this threshold value b1 is also set smaller as the engine speed Ne is smaller. In other words, when accelerating when the engine 9 is running at a low speed, such as when climbing a slope, not only is it easy to set the “supercharging region” even in a region where the engine load is relatively small, but the tendency is stronger than during normal operation. It has become.
When it is determined by the supercharging area setting unit 22 that the engine is in the “supercharging area”, the ECU 20 drives the electric motor 31 via the supercharger driver 11 to operate the electric compressor 3, and supercharges the engine 9. Make a salary. If it is determined that the engine is in the “natural intake area”, the ECU 20 performs natural intake without supercharging the engine 9.

In the present embodiment, the “supercharging region” and the “natural intake region” are determined based on the accelerator opening, and this “supercharging region” and “natural intake region” This determination may be made based on throttle valve opening information of the electronically controlled throttle valve 4 detected by the throttle position sensor 5.
Specifically, a threshold value a2 corresponding to the threshold value a1 and a threshold value b2 corresponding to the threshold value b1 are set, and the throttle opening degree TPS calculated based on the throttle valve opening degree information is set in the normal operation state. Is greater than the threshold value a2, in the acceleration state, it is determined to be the “supercharging region” if it is greater than the threshold value b2, and otherwise determined to be the “natural intake region” (however, these This determination is limited to the case where the electronic control throttle valve 4 is not fully opened). These threshold values a2 and b2 of the throttle opening TPS are given as values that vary according to the engine speed Ne, similarly to the threshold values a1 and b1 of the accelerator opening APS. As described above, the determination of the “supercharging region” and the “natural intake region” may be performed based on the engine load condition, and parameters according to the engine load other than the accelerator position sensor 7 and the throttle position sensor 5 are set. You may perform based on the detection information from the means to detect (engine load detection means).

  As shown in FIG. 3, the target intake pressure setting unit 21 calculates an intake air amount and a target boost pressure Pt to be taken into the engine 9 based on the accelerator opening APS detected by the accelerator position sensor 7. In the calculation of the intake air amount and the target boost pressure Pt, when it is determined that the acceleration state determination unit 23 is “normal operation state”, the map shown in FIG. If it is determined that “is”, the map shown in FIG. 3B is used. In FIGS. 3A and 3B, the threshold values a1 and b1 indicating the boundary between the supercharging region and the natural intake region are shown in FIGS. 4A and 4B corresponding to the engine speed Ne. This corresponds to the threshold values a1 and b1. In the present embodiment, as shown in FIGS. 3A and 3B, when the accelerator opening APS is larger than these thresholds with the thresholds a1 and b1 as boundaries, the accelerator opening APS is increased. The intake air amount is set to increase in proportion.

  First, when it is determined as the “natural intake region” in the supercharging region setting unit 22 (that is, when the accelerator opening APS is equal to or smaller than the threshold value a1 in FIG. 3A, the accelerator opening in FIG. 3B). When the degree APS is equal to or less than the threshold value b1, supercharging by the electric compressor 3 is not performed, and the ECU 20 performs electronic control so that intake of the intake air amount set by the target intake pressure setting unit 21 can be secured by natural intake. The opening degree control of the throttle valve 4 is performed.

  Further, when the “supercharging region” is set in the supercharging region setting unit 22 (that is, when the accelerator opening APS is larger than the threshold value a1 in FIG. 3A, the accelerator in FIG. 3B). When the opening APS is larger than the threshold value b1, the target intake pressure setting unit 21 further calculates a target boost pressure Pt for securing the intake air amount set by the target intake pressure setting unit. In the ECU 20, the electric motor 31 of the electric compressor 3 is rotated so that the target supercharging pressure Pt is achieved, and the electronic control throttle valve 4 is fully opened to perform supercharging. And feedback control is performed based on the detection information of the supercharging pressure sensor 12 so that the target supercharging pressure Pt becomes equal to the supercharging pressure by the electric compressor 3. That is, the ECU 20 drives the electric compressor 3 so as to reach the target boost pressure Pt by feedback control.

  In other words, the target intake pressure setting unit 21 is detected by the detection information of the accelerator position sensor 7 (that is, the accelerator opening APS) or the detection information of the throttle position sensor 5 (that is, the throttle valve opening information) and the engine speed sensor 13. It functions as a target boost pressure setting means for setting the target boost pressure Pt of the electric compressor 3 based on the engine speed information (that is, the engine speed Ne).

Further, the ECU 20 determines that the vehicle is in an acceleration state by the acceleration state determination unit 23, and detects an engine load exceeding a threshold value b1 (first supercharging region determination load) by the accelerator position sensor 7. The electric motor 31 is driven so as to reach the target boost pressure, and the electronic control throttle valve 4 functions as a control means that is almost fully opened.
The control device for the engine with the electric supercharger according to the present embodiment is configured as described above, and is controlled as follows according to the flowchart shown in FIG. This flow is appropriately executed in a predetermined cycle in the ECU 20 when the engine 9 is started.

First, in step S10, from the throttle position sensor 5, the accelerator position sensor 7, the boost pressure sensor 12, and the engine speed sensor 13, the throttle valve opening TPS, the accelerator opening APS, the boost pressure (in the intake passage), respectively. Air pressure) P and engine speed Ne are input.
Next, the routine proceeds to step S20, where the time change ΔAPS of the accelerator opening APS is calculated, and it is determined whether or not this ΔAPS is larger than the acceleration determination threshold value K. This is determined by the acceleration state determination unit 23 of the ECU 20. That is, in this step, it is determined whether or not the vehicle is in an acceleration state.

  Here, if ΔAPS> K (the acceleration state), the process proceeds to step S30, and whether or not the accelerator opening APS is larger than the threshold value b1 (or whether or not the throttle opening TPS is larger than the threshold value b2). ) Is determined. This is determined by the supercharging region determination unit 22 of the ECU 20. That is, in this step, it is determined whether the intake control to be performed is supercharging control or natural intake control. In this determination, the determination condition in the “acceleration state” is used.

  If APS> b1 (or TPS> b2), the process proceeds to step S40 to start supercharging control. First, in step S50, the intake air amount is calculated based on the map shown in FIG. 3B, and the supercharging pressure required to inhale the intake air amount is calculated as the target supercharging pressure Pt. To do. This is calculated in the target intake pressure setting unit 21 of the ECU 20. Next, in step S60, the ECU 20 controls the rotational speed of the electric motor 31 to achieve the target boost pressure Pt, thereby controlling the electric compressor 3 and controlling the electronically controlled throttle valve 4 to be fully opened. Then, the process proceeds to step S70.

  In step S70, the ECU 20 determines whether or not the boost pressure P detected by the boost pressure sensor 12 is equal to the target boost pressure Pt. When P ≠ Pt, the target supercharging pressure required for the engine 9 has not been achieved. Therefore, this step is repeated and the supercharging by the electric compressor 3 is continued until the target supercharging pressure Pt is achieved. Then, when the target supercharging pressure is achieved and P = Pt, or when the target supercharging pressure Pt substantially coincides, this control is terminated.

  On the other hand, if ΔAPS ≦ K (in the normal operation state) in step S20, the process proceeds to step S80. In step S80, as in step S30, it is determined whether the intake control to be performed is supercharging control or natural intake control. Here, the determination condition in the “natural intake state” is It is used to determine whether the accelerator opening APS is larger than the threshold value a1 (or whether the throttle opening TPS is larger than the threshold value a2).

  If APS> a1 (or TPS> a2), the process proceeds to step S90 and supercharging control is started. In step S100, the intake air amount is calculated based on the map shown in FIG. 3A, and the intake pressure required to inhale the intake air amount is calculated as the target boost pressure Pt. The target boost pressure Pt calculated here is set based on a map different from the target air pressure calculated in step S50. And it progresses to step S60 and supercharging control is performed.

If it is determined in step S80 that APS> a1 (or TPS> a2) is not satisfied, the process proceeds to step S110 to perform natural intake control, and this control is terminated. In addition, also when it is not APS> b1 (or TPS> b2) in step S30, it progresses to step S80 and performs the above-mentioned control.
Specifically, the following effects are obtained by the control as described above.

  First, when the accelerator pedal 6 is strongly depressed by the driver and the time change ΔAPS of the accelerator opening APS becomes larger than the acceleration determination threshold K, that is, when the vehicle accelerates, the determination condition in the acceleration state is used. It is determined whether or not supercharging is performed. As shown in FIG. 3B and FIG. 4B, the determination condition in the acceleration state has a wider supercharging region than the determination condition in the normal operation state (that is, it is easily determined that it is the supercharging region). Since it is set, it becomes easier to supercharge in the acceleration state than in the normal operation state. Therefore, the response delay of the opening operation of the electronically controlled throttle valve 4 is reduced, and the response performance of the boost pressure increase during vehicle acceleration and the acceleration performance of the vehicle can be improved.

Further, when supercharging is started, the electronic control throttle valve 4 is controlled to be fully opened, so that no pressure loss due to the electronic control throttle valve 4 occurs, and the intake air amount can be increased. Output can be improved.
Further, since the electronically controlled throttle valve 4 is fully opened at the time of supercharging, the target supercharging pressure Pt can be set at an early stage with the accelerator opening APS representing the driver's required output, and then the target is controlled by feedback control. Since it is possible to quickly converge to the supercharging pressure, the acceleration response performance can be further improved.

  In addition, in this control device, supercharging is not performed immediately when the vehicle is accelerated, but is set so that the supercharging condition during normal operation is expanded, and supercharging is performed only when the condition is satisfied. Therefore, the electric motor 31 of the electric compressor 3 is not excessively operated and the battery 10 is not consumed, and the power consumption can be suppressed. When the above acceleration condition is satisfied, Acceleration with good response performance can be performed.

  On the other hand, when the accelerator pedal 6 is not so depressed by the driver and the time change ΔAPS of the accelerator opening APS is equal to or less than the acceleration determination condition K, that is, when the vehicle is in the normal driving state, it exceeds Since the supply range is set narrow (that is, it is easy to determine that it is a natural intake range), the engine 9 is not excessively charged, and the battery 10 is consumed due to frequent operation of the electric compressor 3. Can be suppressed.

  Even during such normal operation, once the supercharging region is set, the opening degree of the electronic control throttle valve 4 is fully opened, so that the pressure loss due to the electronic control throttle valve 4 can be reduced. The target boost pressure Pt can be set at an early stage with the accelerator opening APS representing the driver's required output, and then it can be quickly converged to the target boost pressure by feedback control. The performance can be further improved.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and various modifications can be made without departing from the spirit of the present invention.
In the above-described embodiment, the electric compressor 3 is a centrifugal compressor type supercharger that performs supercharging by rotating the turbine wheel 32 by the electric motor 31. For example, a roots type supercharger is used. May be configured.

  In the above-described embodiment, the supercharging region setting unit 22 is configured to set the supercharging control or the natural intake control by comparing the accelerator opening APS and a1 and b1, but during the natural intake control, Since a correlation is established between the accelerator opening APS and the opening of the electronically controlled throttle valve 4, this determination may be made using the throttle opening TPS instead of the accelerator opening APS. .

1 is a schematic diagram showing an overall configuration of a control device for an engine with an electric supercharger as an embodiment of the present invention. It is sectional drawing which shows the structure of the electric compressor concerning the control apparatus of the engine with an electric supercharger as one Embodiment of this invention. 1 is a map showing throttle characteristics at the time of engine low rotation of a control device for an engine with an electric supercharger as one embodiment of the present invention, (a) is a throttle characteristic diagram during normal operation, (b) is during acceleration FIG. FIG. 2 is a characteristic map for determining whether or not to perform supercharging in the control device for an engine with an electric supercharger as one embodiment of the present invention, wherein (a) is a characteristic map during normal operation, and (b) is acceleration It is a characteristic map at the time. It is a flowchart for demonstrating the supercharging control in the control apparatus of the engine with an electric supercharger as one embodiment of the present invention. In the control apparatus for an engine with an electric supercharger as a conventional example, it is a map showing a throttle characteristic at the time of engine low rotation.

Explanation of symbols

1 Control device for engine with electric supercharger 2 Reed valve 3 Electric compressor (electric supercharger)
4 Electronically controlled throttle valve 5 Throttle position sensor (engine load detection means)
6 Accelerator pedal 7 Accelerator position sensor (Accelerator operation amount detection means, engine load detection means)
DESCRIPTION OF SYMBOLS 8 Air cleaner 9 Engine 10 Battery 11 Supercharger driver 12 Supercharging pressure sensor 13 Engine speed sensor (engine speed detection means)
14 Bypass passage 20 ECU (electronic control unit, control means)
21 Target intake pressure setting unit (target boost pressure setting means)
22 Supercharging area setting section (Supercharging area setting means)
23 Acceleration state determination unit (acceleration state determination means)
31 Electric motor
32 Centrifugal compressor

Claims (7)

An electric supercharger provided in an intake system of an engine mounted on a vehicle and driven by an electric motor to supercharge intake air;
An electronically controlled throttle valve that is provided in the intake system of the engine and can be controlled independently of the driver's accelerator operation;
Engine rotation speed detection means for detecting the rotation speed of the engine;
Engine load detecting means for detecting the load of the engine;
Acceleration state determining means for determining the acceleration state of the vehicle;
Target boost pressure setting means for setting a target boost pressure of the electric supercharger based on the engine load detected by the engine load detection means and the engine rotation speed detected by the engine rotation speed detection means;
When it is determined by the acceleration state determination means that the vehicle is in an acceleration state and the engine load detected by the engine load detection means exceeds a preset first supercharging region determination load, the target supercharging A control device for an engine with an electric supercharger, comprising: a control means for driving the electric motor to be at a pressure and opening the electronically controlled throttle valve substantially fully. 2. The engine with an electric supercharger according to claim 1, wherein the engine load detecting means is an accelerator operation amount detecting means for detecting an accelerator operation amount by a driver as a parameter corresponding to a state of the engine load. Control device. 3. The control device for an engine with an electric supercharger according to claim 1, wherein the acceleration state determination means determines an acceleration state of the vehicle based on an accelerator operation amount by a driver. The control means determines that the vehicle is not in an accelerated state by the acceleration state determination means, and the engine load is preset by the engine load detection means as a value higher than the first supercharging region determination load. When it is detected that the second supercharging region determination load has been exceeded, the electric motor is driven so as to achieve the target supercharging pressure, and the electronically controlled throttle valve is fully opened or substantially fully opened. The control device for an engine with an electric supercharger according to any one of claims 1 to 3. Supercharging region setting means for setting a supercharging region and a natural intake region of the engine based on the engine load and the engine speed,
The electric motor drives the electric supercharger in the supercharging region of the engine set by the supercharging region setting means,
5. The motor according to claim 1, wherein when the acceleration state determination unit determines that the vehicle is in an acceleration state, the motor is driven based on the setting of the supercharging region setting unit. The engine control apparatus with an electric supercharger as described in 1. The control device for an engine with an electric supercharger according to any one of claims 1 to 5, wherein the control means drives the electric motor to be the target supercharging pressure by feedback control. . The first supercharging region determination load and / or the second supercharging region determination load is set as a boundary value between the supercharging region and the natural intake region in the supercharging region setting means. The control device for an engine with an electric supercharger according to claim 4.

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