JP2007023837A - Control device of internal combustion engine having supercharger with electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To optimally control an internal combustion engine in consideration of a pressure difference between intake pressure and exhaust pressure increased with operation of an electric motor. <P>SOLUTION: A valve-overlapping period B in operation of the electric motor (when the electric motor is tuned on) is controlled by controlling operation timing of an intake valve by a VVT mechanism so that it is longer than a valve-overlapping period A in non-supercharging and shorter than a valve-overlapping period C in non-operation of the electric motor (when the electric motor is turned off). When output of the electric motor is large, the valve-operating period B is controlled to be short as compared with when the output is small. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control device for an internal combustion engine having a supercharger with an electric motor.

  2. Description of the Related Art An internal combustion engine with a supercharger that increases the amount of air blown from an intake passage to an exhaust passage by expanding a valve overlap period during a transition is known (see, for example, Patent Document 1). According to this internal combustion engine, by reburning the unburned HC in the exhaust gas, the exhaust energy can be increased and the transient performance can be improved.

  An internal combustion engine having a supercharger with an electric motor is known (for example, refer to Patent Document 2). According to this internal combustion engine, the turbo lag in the low rotation range can be eliminated.

JP 2004-245104 A JP 2003-328861 A JP 2003-269203 A

  When the electric motor is operated, the exhaust pressure relative to the intake pressure is relatively lower than when supercharging is performed without operating the electric motor. That is, by operating the electric motor, the differential pressure between the intake pressure and the exhaust pressure becomes very large. In such a case, if the valve overlap period is extended as described above in order to improve the transient performance, the amount of air and fuel blown from the intake passage to the exhaust passage is significantly increased. As a result, fuel consumption and emissions may be deteriorated.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to optimally control an internal combustion engine in consideration of a differential pressure between intake pressure and exhaust pressure that has increased with the operation of an electric motor. To do.

In order to achieve the above object, a first invention is a control device for an internal combustion engine having a supercharger with an electric motor,
A supercharger having a rotating portion of a compressor provided in an intake passage of the internal combustion engine, and an electric motor capable of driving the rotating portion;
A valve overlap control means for controlling the valve overlap period by changing the operation timing of the intake valve or the exhaust valve,
The valve overlap control means shortens the valve overlap period when the electric motor is operating, compared to when the electric motor does not operate and is supercharged by the supercharger. It is characterized by doing.

  In a second aspect based on the first aspect, the valve overlap control means shortens the valve overlap period when the output of the electric motor is large compared to when the output is small. Features.

Further, in a third invention according to the second invention, an external EGR passage for circulating a part of the exhaust gas to the intake passage;
An external EGR valve that opens and closes the external EGR passage;
External EGR valve opening that increases the opening of the external EGR valve when the motor is operating and when the motor does not operate and is supercharged by the supercharger And a control means.

The fourth invention is a control device for an internal combustion engine having a supercharger with an electric motor,
A supercharger having a rotating portion of a compressor provided in an intake passage of the internal combustion engine, and an electric motor capable of driving the rotating portion;
An ignition timing control means for advancing the ignition timing when the electric motor is operating as compared to when the electric motor is not operating and is supercharged by the supercharger; It is characterized by.

  Further, a fifth invention is characterized in that, in the fourth invention, the ignition timing control means advances the ignition timing when the output of the electric motor is large compared to when the output is small. To do.

  According to the first invention, when the electric motor is operating, the valve overlap period is shortened compared to the case where the electric motor does not operate and supercharging is performed. As a result, it is possible to suppress excessive blowout of fuel and air from the intake passage to the exhaust passage during the valve overlap period. Therefore, sufficient transient performance can be obtained when the electric motor is operating.

  According to the second aspect of the invention, the optimal valve overlap period can be controlled according to the output of the electric motor.

  According to the third invention, when the electric motor is operating, the opening degree of the external EGR valve is made larger than when the electric motor does not operate and supercharging is performed. Thereby, when the electric motor is operating, a sufficient amount of external EGR can be obtained, and a sufficient NOx reduction effect can be obtained.

  According to the fourth invention, when the electric motor is operating, the differential pressure between the intake pressure and the exhaust pressure is sufficiently large, so that a good knocking characteristic can be obtained. Therefore, when the electric motor is operating, the ignition timing can be advanced and sufficient output torque can be obtained compared to the case where supercharging is performed without operating the electric motor.

  According to the fifth aspect, it is possible to control the output torque to be optimum according to the output of the electric motor.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted.

Embodiment 1 FIG.
[Description of system configuration]
FIG. 1 is a diagram showing a system configuration according to Embodiment 1 of the present invention. The system according to the first embodiment is an internal combustion engine having a supercharger with a motor (motor-assisted turbocharger).
The internal combustion engine 1 according to the first embodiment includes a cylinder block 2. Although not shown, the cylinder block 2 is provided with, for example, four cylinders 4 in series. FIG. 1 shows only one cylinder 4.

  A piston 6 is provided inside each cylinder 4. The piston 6 is connected to the crankshaft 8 via a crank mechanism. A crank angle sensor 10 is provided in the vicinity of the crankshaft 8. The crank angle sensor 10 is configured to detect the rotation angle of the crankshaft 8 (hereinafter referred to as “crank angle”).

  The cylinder block 2 is provided with a water temperature sensor 12. The water temperature sensor 12 is configured to detect a cooling water temperature circulating in the internal combustion engine 1.

  A cylinder head 14 is assembled to the upper part of the cylinder block 2. A space from the upper surface of the piston 6 to the cylinder head 14 forms a combustion chamber 16. The cylinder head 14 is provided with a spark plug 18 that ignites the air-fuel mixture in the combustion chamber 16.

  The cylinder head 14 includes an intake port 20 that communicates with the combustion chamber 16. An intake valve 22 is provided at a connection portion between the intake port 20 and the combustion chamber 16. The intake valve 22 is connected to a variable valve timing mechanism (hereinafter referred to as “VVT mechanism”) 23. The VVT mechanism 23 can change the operation timing of the intake valve 22.

  An injector 24 for injecting fuel is provided in the vicinity of the intake port 20. An intake passage 26 is connected to the intake port 20. An intake pressure sensor 28 is provided in the intake passage 26. The intake pressure sensor 28 is configured to measure the pressure of air supercharged by a compressor 42a (to be described later) (hereinafter referred to as “intake pressure”). A surge tank 30 is provided upstream of the intake pressure sensor 28.

  A throttle valve 32 is provided upstream of the surge tank 30. The throttle valve 32 is an electronically controlled valve that is driven by a throttle motor 34. The throttle valve 32 is driven based on the accelerator opening AA detected by the accelerator opening sensor 36. In the vicinity of the throttle valve 32, a throttle opening sensor 38 is provided. The throttle opening sensor 38 is configured to detect the throttle opening TA.

  An intercooler 40 is provided upstream of the throttle valve 32. The intercooler 40 is configured to cool the supercharged air.

A compressor 42 a of a turbocharger with an electric motor (hereinafter referred to as “MAT”) 42 is provided upstream of the intercooler 40. The impeller as the rotating portion 42e of the compressor 42a is connected to the turbine 42b via a connecting shaft 42c. The turbine 42b is provided in an exhaust passage 54 described later. The turbine 42b is rotationally driven by the exhaust energy, so that the impeller 42e is rotationally driven.
An AC motor that is an electric motor 42d is provided between the compressor 42a and the turbine 42b. The electric motor 42 d is connected to the motor controller 43. The motor controller 43 is configured to supply electric power to the electric motor 42d. The drive shaft of the electric motor 42d also serves as the connecting shaft 42c. Therefore, the impeller 42e is configured to be forcibly driven to rotate by the electric motor 42d.

  An air flow meter 46 is provided upstream of the compressor 42a. The air flow meter 46 is configured to detect the intake air amount GA. An air cleaner 47 is provided upstream of the air flow meter 46. The upstream of the air cleaner 47 is open to the atmosphere.

  One end of an intake bypass passage 44 is connected between the compressor 42 a and the air flow meter 46. The other end of the intake bypass passage 44 is connected between the compressor 42 a and the intercooler 40. An intake bypass valve 45 is provided in the intake bypass passage 44. When the intake bypass valve 45 is opened, a part of the air supercharged by the MAT 42 is returned to the intake side of the compressor 42a through the intake bypass passage 44. Thereby, the pressure of the compressor 42a can be reduced.

  In addition, the cylinder head 14 includes an exhaust port 48 that communicates with the combustion chamber 16. An exhaust valve 50 is provided at a connection portion between the exhaust port 48 and the combustion chamber 16. The exhaust valve 50 is connected to the VVT mechanism 51. The VVT mechanism 51 is configured to be able to change the operation timing of the exhaust valve 50. An exhaust passage 52 is connected to the exhaust port 48. An air-fuel ratio sensor 54 is provided in the exhaust passage 52. The air-fuel ratio sensor 54 is configured to detect the exhaust air-fuel ratio. A turbine 42 b of the MAT 42 is provided downstream of the air-fuel ratio sensor 54. The turbine 42b is configured to be rotationally driven by the energy of the exhaust gas flowing through the exhaust passage 52. A catalyst 56 for purifying exhaust gas is provided downstream of the turbine 42b.

  In addition, one end of an external EGR passage 57 is connected to the exhaust passage 52. The other end of the external EGR passage 57 is connected to the surge tank 30. An external EGR valve 58 is provided in the external EGR passage 57. When the external EGR valve 58 is opened, a part of the exhaust gas is returned to the intake passage 26 through the external EGR passage 57. Since the exhaust gas has a smaller amount of oxygen than air, the amount of NOx produced can be reduced.

The system according to the first embodiment includes an ECU (Electronic Control Unit) 60 that is a control device.
The crank angle sensor 10, the coolant temperature sensor 12, the intake pressure sensor 28, the accelerator opening sensor 36, the throttle opening sensor 38, the air flow meter 46, the air-fuel ratio sensor 54, and the like are connected to the input side of the ECU 60.
Further, the injector 18, the VVT mechanisms 23 and 51, the injector 24, the throttle motor 34, the motor controller 43, the intake bypass valve 45, the external EGR valve 58, and the like are connected to the output side of the ECU 60.
The ECU 60 calculates the engine speed NE based on the output of the crank angle sensor 52.
The ECU 60 calculates the supply voltage to the electric motor 42d so that the desired intake pressure is obtained. Further, the ECU 60 instructs the motor controller 43 to supply the calculated electric power to the electric motor 42d.
The ECU 60 controls the drive of the VVT mechanism 23 so that a desired overlap period is reached, as will be described later.

[Features of Embodiment 1]
The system can perform supercharging by rotating the impeller 42e of the compressor 42a by exhaust energy (that is, by driving the turbine 42b). Further, not only supercharging by the exhaust energy, but supercharging can be performed by operating the electric motor 42d to forcibly rotate the impeller 42e. Thereby, the turbo lag in the low rotation region where the exhaust energy is small can be eliminated.

By the way, when supercharging is performed by operating the motor 42d, the intake pressure relative to the exhaust pressure becomes very high compared to when supercharging is performed only with exhaust energy without operating the motor 42d. That is, when the electric motor 42d is operated, the differential pressure between the intake pressure and the exhaust pressure increases.
If the valve overlap period is increased when the differential pressure is large, the amount of fuel and air blown from the intake passage 26 to the exhaust passage 52 is significantly increased. As a result, sufficient transient performance could not be obtained, and conversely, there was a possibility that fuel consumption and emissions would deteriorate.

Therefore, in the first embodiment, the valve overlap period when the motor 42d is operated for supercharging is longer than when the motor 42d is not supercharged, and when the motor 42d is not operated for supercharging. shorten.
FIG. 2 is a diagram showing operating characteristics of the intake valve 22 and the exhaust valve 50 and a valve overlap period in the first embodiment. In FIG. 2, the operating characteristic of the intake valve 22 when the motor 42d is operated to perform supercharging (hereinafter referred to as “when the motor is ON”) is shown by a straight line. Further, the operating characteristics of the intake valve 22 when supercharging is performed only with exhaust energy without operating the motor 42d (hereinafter referred to as “when the motor is OFF”) are indicated by a one-dot chain line. Furthermore, the operating characteristic of the intake valve 22 when supercharging is not performed (hereinafter referred to as “non-supercharging”) is indicated by a wavy line. The operating characteristics of the exhaust valve 50 are the same when the motor is ON, when the motor is OFF, and when the motor is not supercharged.

As shown in FIG. 2, when the electric motor is ON, the valve opening timing of the intake valve 22 is set to the advance side as compared with the non-supercharging state. For this reason, the valve overlap period B when the motor is ON is longer than the valve overlap period A when non-supercharging. Therefore, the flow of fuel and air from the intake passage 26 to the exhaust passage 52 can be secured. Thereby, unburned HC can be burnt most and exhaust energy can be increased.
Further, when the motor is ON, the opening timing of the intake valve 22 is set to the retarded side compared to when the motor is OFF. For this reason, the valve overlap period B when the motor is ON is shorter than the valve overlap period C when the motor is OFF. Therefore, an excessive flow of fuel and air from the intake passage 26 to the exhaust passage 52 can be suppressed.

  Therefore, according to the first embodiment, the valve overlap period B when the motor is ON is longer than the valve overlap period A when the motor is not supercharged and shorter than the valve overlap period C when the motor is OFF. It will be lost. Thereby, even when the motor 42d is operated, it is possible to suppress an excessive flow of fuel and air from the intake passage 26 to the exhaust passage 52. Therefore, even when supercharging is performed by operating the electric motor 42d, it is possible to obtain the optimum amount of fuel and air blown from the intake passage 26 to the exhaust passage 52, and to obtain sufficient transient performance.

Further, the larger the output (%) of the electric motor 42d, that is, the larger the electric power supplied from the motor controller 43 to the electric motor 42d, the higher the intake pressure relative to the exhaust pressure. Therefore, the greater the output of the motor 42d, the greater the differential pressure between the intake pressure and the exhaust pressure. As described above, the greater the differential pressure, the more excessive the flow of fuel and air from the intake passage 26 to the exhaust passage 52 occurs.
Therefore, in the first embodiment, when the output of the electric motor 42d is large, the retard amount of the operation timing of the intake valve 22 is reduced as compared with the case where the output is small. That is, the valve overlap period B is shortened as the output of the electric motor 42d increases. Accordingly, the optimum operation timing of the intake valve 22 is calculated in consideration of the increase in the differential pressure between the intake pressure and the exhaust pressure accompanying the operation of the electric motor 42d, and the optimum valve overlap period B is calculated.

[Specific Processing in Embodiment 1]
FIG. 3 is a flowchart showing a routine executed by the ECU 60 in the first embodiment.
According to the flow shown in FIG. 3, first, the engine speed NE (rpm), the intake pressure PIM (kPa), and the power supply value to the motor 42d are acquired (step 100).

  Next, it is determined whether or not the intake pressure PIM is greater than a predetermined value (step 102). In this step 102, it is determined whether or not supercharging is performed by the supercharger 42. If it is determined in step 102 that the intake pressure PIM is less than or equal to the predetermined value, for example, if the accelerator is not depressed by the vehicle driver and the throttle opening TA is fully closed, this routine is terminated. In this case, the ECU 60 calculates the operation timing of the intake valve 22 during non-supercharging based on the engine speed NE and the intake pressure PIM in a routine different from this routine. As shown in FIG. 2, the calculated operation timing of the intake valve 22 at the time of non-supercharging is on the retard side with respect to the operation timing when the motor is ON. Therefore, the valve overlap period A when non-supercharging is shorter than the valve overlap period B when the motor is ON.

If it is determined in step 102 that the intake pressure PIM is greater than the predetermined value, that is, if supercharging is performed by the supercharger 42, it is determined whether or not the electric motor 42d is operating. A determination is made (step 104). If it is determined in step 104 that the electric motor 42d is in operation, the operation timing of the intake valve 22 when the electric motor is operated is calculated with reference to a map stored in advance in the ECU 60 (step 106). That is, the advance angle target value of the intake system VVT 23 when the electric motor is operated is calculated.
In this map, the operation timing of the intake valve 22 is set according to the engine speed NE, the intake pressure PIM, and the supply power value acquired in step 100. According to the map, an operation timing that is retarded (that is, the amount of advance angle is smaller) than the operation timing when the motor is not operated, which will be described later, is calculated. This is because when the motor is operating, the differential pressure between the intake pressure and the exhaust pressure is larger than when the motor is not operating, and if the valve overlap period is lengthened, the amount of fuel and air blown from the intake passage 26 to the exhaust passage 52 is increased. This is because of the increase.
Further, according to the map, when the supply power value to the electric motor 42d is large, the operation timing on the retard side is calculated more than when the supply power value is small. For this reason, when the supply power value is large, the valve overlap period is shortened compared to when the supply power value is small.

On the other hand, when it is determined in step 104 that the electric motor 42d is not operating, that is, when supercharging is performed only with the exhaust energy, the process of step 108 is executed. In step 108, the operation timing of the intake valve 22 when the motor is not operated is calculated with reference to a map stored in advance in the ECU 60. That is, the advance angle target value of the intake system VVT 23 when the electric motor is not operated is calculated. The map for when the motor is not operated referred to in step 108 is a map different from the map for when the motor is operated referred to in step 106.
In the map for when the electric motor is not operated, the operation timing of the intake valve is set according to the engine speed NE, the intake pressure PIM, and the supplied power acquired in step 100 above. According to the map, the operation timing on the advance side (that is, the amount of advance angle is larger) than the operation timing when the electric motor is operated is calculated. This is because when the motor is not operating, the differential pressure between the intake pressure and the exhaust pressure is smaller than when the motor is operating, and even if the valve overlap period is extended, excessive fuel and air flow from the intake passage 26 to the exhaust passage 52 is caused. This is because there is no blowing flow.
Further, according to the map, similarly to the map for operating the electric motor, when the supply power value to the motor 42d is large, the operation timing on the retard side is larger than when the supply power value is small. Is calculated. For this reason, when the supply power value is large, the valve overlap period is shortened compared to when the supply power value is small.

Thereafter, the intake system VVT 23 is driven so that the operation timing calculated in step 106 or 108 is reached. Thereby, a desired overlap period is set.
When this routine is started after the next time, the operation timing of the intake valve 22 is calculated according to the operation or non-operation of the electric motor 42d.

  As described above, according to the routine shown in FIG. 3, when the electric motor 42d is operating and when the electric motor 42d is inactive and supercharging is performed only with exhaust energy, The operation timing of the intake valve 22 is calculated with reference to a different map. As a result, the valve overlap period during operation of the electric motor is made longer than the valve overlap period during non-supercharging, and is also made shorter than the valve overlap period during supercharging using only exhaust energy when the electric motor is not operating. Further, when the power supply value to the electric motor 42d is large, the operation timing on the more retarded side is calculated and the valve overlap period is made shorter than when the power supply value is small. Therefore, the valve overlap period can be optimally controlled in accordance with the increase in the differential pressure accompanying the operation of the electric motor 42d.

In the first embodiment, the system for controlling the valve overlap period by controlling the advance amount of the operation timing of the intake valve 22 by the VVT 23 has been described. However, the present invention is not limited to this, and the operation of the exhaust valve 50 is not limited thereto. The valve overlap period may be controlled by controlling the timing retard amount (hereinafter referred to as “retard amount”) by the VVT 51. In this case, the retard amount of the exhaust valve operation timing when the motor is activated is larger than the retard amount when non-supercharging, and is smaller than the retard amount when supercharging only with exhaust energy when the motor is not activated. By doing so, the same effect as in the first embodiment can be obtained.
Further, instead of a system that changes the operation timing of the intake valve 22 by the VVT 23, a system that changes the operation timing by an electromagnetically driven valve mechanism can be used. Also in this case, the same effect as in the first embodiment can be obtained.

In Patent Document 1 described above, transient performance is improved by enlarging the valve overlap, but engines other than the three-cylinder supercharged engine (in-line three-cylinder, V-type six-cylinder) (in-line four Cylinders, V-type 8-cylinders, in-line 6-cylinders, etc.) are not applicable. In these engines, due to exhaust interference (exhaust pulsation from other cylinders), the exhaust pressure becomes higher than the intake pressure at the time of valve overlap, and the blow-through cannot be realized. In order to realize the blow-through, a special improvement of the exhaust system is required, and the cost is remarkably increased.
On the other hand, the present invention can be applied to all engines because the intake pressure is sufficiently higher than the exhaust pressure during valve overlap.

  In the first embodiment, the “valve overlap control means” in the first and second inventions is realized by the ECU 60 executing the process of step 106.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIG. The system of the second embodiment can be realized by causing the ECU 60 to execute a routine shown in FIG. 4 to be described later using the hardware configuration shown in FIG.

[Features of Embodiment 2]
In the system shown in FIG. 1, a part of the exhaust gas can be circulated to the intake passage 26 via the external EGR passage 57 by opening the external EGR valve 58. Thereby, the amount of NOx discharged from the internal combustion engine can be reduced.

  By the way, when the motor is operated, the exhaust pressure relative to the intake pressure is lower than when the motor is not operated. That is, when the motor is operated, the differential pressure between the intake pressure and the exhaust pressure is larger than when the motor is not operated. Therefore, when the intake pressure is the same, the amount of external EGR is smaller when the motor is operating than when the motor is not operating. For this reason, a sufficient NOx reduction effect may not be obtained.

  Therefore, in the second embodiment, the opening degree of the external EGR valve 58 when the electric motor 42d is operated and supercharged is made larger than when the electric motor 42d is operated without being operated. That is, considering the relative exhaust pressure drop due to the operation of the electric motor 42d, the opening degree of the external EGR valve 58 when the electric motor is operating is made larger than the opening degree when the electric motor is not operating. As a result, a sufficient amount of external EGR can be ensured even when the motor is operating, and a sufficient NOx reduction effect can be obtained.

[Specific Processing in Second Embodiment]
FIG. 4 is a flowchart showing a routine executed by the ECU 60 in the second embodiment.
In the routine shown in FIG. 4, step 110 is added after step 106 in the first embodiment, and step 112 is added after step 108.

That is, according to this routine, after the intake valve operation timing at the time of motor operation is calculated in step 106, the processing of step 110 is executed. In step 110, the opening degree of the external EGR valve 58 when the electric motor is operated is calculated with reference to a map stored in advance in the ECU 60. In the map, the opening degree of the external EGR valve 58 is set according to the engine speed NE, the intake pressure PIM, and the supply power value acquired in step 100. According to this map, an opening degree larger than the opening degree of the external EGR valve 58 when the electric motor described later is not operated is calculated. This is because the exhaust pressure relative to the intake pressure is greatly reduced when the motor is operating, and the amount of external EGR is smaller than when the motor is not operating.
Further, according to the map, when the power supply value to the electric motor 42d is large, the opening degree of the external EGR valve 58 is made larger than when the power supply value is small. This is because, as the output of the electric motor 42d is larger, the exhaust pressure is greatly reduced, so that the external EGR amount becomes smaller.

On the other hand, after the intake valve operating timing when the motor is not operated is calculated in step 108, the processing of step 112 is executed. In step 112, the opening degree of the external EGR valve 58 is calculated with reference to a map stored in advance in the ECU 60 when the motor is not operating (that is, when supercharging is performed only with exhaust energy). The map for when the motor is not operated referred to in step 112 is a map different from the map for when the motor is operated referred to in step 110.
In the map for when the electric motor is not operated, the opening degree of the external EGR valve 58 is set according to the engine speed NE, the intake pressure PIM, and the supplied power acquired in step 100. According to the map, an opening smaller than the opening of the external EGR valve 58 when the electric motor is operated is calculated. This is because when the motor is not operated, the relative exhaust pressure drop is smaller than when the motor is operated.
Further, according to the map, as in the map for operating the motor, when the supply power value to the motor 42d is large, the external EGR valve 58 is opened compared to when the supply power value is small. The degree is increased. For this reason, when the output of the motor 42d is large, the opening degree is calculated smaller than when the output is small.

Thereafter, the external EGR valve 58 is opened so that the opening calculated in step 110 or 112 is reached.
When this routine is started after the next time, the opening degree of the external EGR valve 58 is calculated in accordance with the operation or non-operation of the electric motor 42d.

  As described above, according to the routine shown in FIG. 4, the opening degree of the external EGR valve 58 is calculated with reference to different maps when the electric motor 42d is operating and when it is not operating. Therefore, the opening degree of the external EGR valve 58 can be optimally controlled according to the increase in the differential pressure accompanying the operation of the electric motor 42d, and a sufficient amount of external EGR can be obtained.

  In the second embodiment, the “external EGR valve opening degree control means” according to the third aspect of the present invention is realized by the ECU 60 executing the process of step 110.

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described with reference to FIG. The system of the third embodiment can be realized by causing the ECU 60 to execute a routine shown in FIG. 5 described later using the hardware configuration shown in FIG.

[Features of Embodiment 3]
As described in the first embodiment, when the supercharging is performed by operating the electric motor 42d, the intake pressure and the exhaust pressure are reduced as compared with the case where the supercharging is performed only with the exhaust energy without operating the electric motor 42d. The differential pressure increases. When this differential pressure increases, the burnt gas in the combustion chamber 16 is efficiently discharged into the exhaust passage 52, and the residual amount of burnt gas in the combustion chamber 16 is reduced. As a result, good knocking characteristics can be obtained.
In the third embodiment, the ignition timing when the motor is operated is advanced more than when the motor is not operated. As described above, when the motor is operated, the amount of burned gas remaining in the cylinder is small, and therefore the ignition timing can be greatly advanced. Thereby, sufficient output torque can be obtained without causing knocking.

[Specific Processing in Embodiment 3]
FIG. 5 is a flowchart showing a routine executed by the ECU 60 in the third embodiment.
First, similarly to the first embodiment, the processing up to step 104 is executed.
If it is determined in step 104 that the motor 42d is in operation, the ignition timing when the motor is operated is calculated with reference to a map stored in advance in the ECU 60 (step 114).
In the map, the ignition timing of the spark plug 18 is set according to the engine speed NE, the intake pressure PIM, and the supply power value acquired in step 100 above. According to the map, the ignition timing that is retarded from the ignition timing when the motor is not operated, which will be described later, is calculated. In other words, if the engine is operating under the same operating conditions (engine speed NE and intake pressure PIM) and the engine is supercharged, the ignition timing when the motor is operating is advanced than the ignition timing when the motor is not operating. On the side. This is because when the motor is activated, the differential pressure between the intake pressure and the exhaust pressure is larger than when the motor is not activated, and the residual amount of burned gas in the cylinder is small, so the amount of advance is increased without causing knocking. Because it can.
Further, according to the map, when the supply power value to the motor 42d is large, the ignition timing on the more advanced side is calculated as compared with the case where the supply power value is small. This is because when the supply power value to the motor 42d is large, that is, when the output of the motor 42d is large, the differential pressure between the intake pressure and the exhaust pressure is larger than when the output is small, so the margin for knocking is large. Because.

On the other hand, when it is determined in step 104 that the electric motor 42d is not operating, that is, when supercharging is performed only with the exhaust energy, the process of step 116 is executed. In step 116, the ignition timing when the motor is not operated is calculated with reference to a map stored in advance in the ECU 60. The map for when the motor is not operated referred to in Step 116 is a map different from the map for when the motor is operated referred to in Step 114.
In the map, the ignition timing of the spark plug 18 is set according to the engine speed NE, the intake pressure PIM, and the supply power value acquired in step 100 above. According to the map, the ignition timing that is retarded from the ignition timing when the motor is operated is calculated. Further, according to the map, similarly to the map for operating the electric motor, when the supply power value to the motor 42d is large, the ignition on the more advanced side than the case where the supply power value is small. The time is calculated.

Thereafter, ignition is performed by the spark plug 18 at the ignition timing calculated in step 114 or 116.
When this routine is started after the next time, the ignition timing by the spark plug 18 is calculated according to the operation or non-operation of the electric motor 42d.

  As described above, according to the routine shown in FIG. 5, the ignition timing of the spark plug 18 is calculated with reference to different maps depending on whether the motor 42d is operating or not. Thereby, in the same operation state, the ignition timing at the time of operating the motor is set to the ignition timing on the advance side with respect to the ignition timing at the time of non-operation of the motor. Furthermore, when the value of the power supplied to the motor 42d is large, the ignition timing is set to a more advanced side than when it is small. Therefore, the ignition timing can be optimally controlled according to the increase in the differential pressure accompanying the operation of the electric motor 42. Therefore, a sufficient output can be obtained without causing knocking when the electric motor is operated.

  The third embodiment can be executed in combination with the first embodiment. That is, step 114 can be executed after step 106 of the routine shown in FIG. 3, and step 116 can be executed after step 108.

  In the third embodiment, the “ignition timing control means” according to the fourth and fifth aspects of the present invention is realized by the ECU 60 executing the process of step 110.

It is a figure which shows the system configuration | structure by Embodiment 1 of this invention. In Embodiment 1 of this invention, it is a figure which shows the operating characteristic and valve overlap amount of an intake valve and an exhaust valve. 5 is a flowchart showing a routine that is executed by the ECU 60 in the first embodiment of the present invention. In Embodiment 2 of this invention, it is a flowchart which shows the routine which ECU60 performs. In Embodiment 3 of this invention, it is a flowchart which shows the routine which ECU60 performs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Cylinder block 4 Cylinder 6 Piston 8 Crankshaft 10 Crank angle sensor 12 Water temperature sensor 14 Cylinder head 16 Combustion chamber 18 Spark plug 20 Intake port 22 Intake valve 23 VVT mechanism 24 Injector 26 Intake passage 28 Intake pressure sensor 30 Surge tank 32 Throttle valve 34 Throttle motor 36 Accelerator opening sensor 38 Throttle opening sensor 40 Intercooler 42 MAT
42a Compressor 42b Turbine 42c Connecting shaft 42d Electric motor 42e Rotating part 43 Motor controller 44 Intake bypass passage 45 Intake bypass valve 46 Air flow meter 47 Air cleaner 48 Exhaust port 50 Exhaust valve 51 VVT mechanism 52 Exhaust passage 54 Air-fuel ratio sensor 56 Catalyst 57 External EGR passage 58 External EGR valve 60 ECU

Claims (5)

A control device for an internal combustion engine having a supercharger with an electric motor,
A supercharger having a rotating portion of a compressor provided in an intake passage of the internal combustion engine, and an electric motor capable of driving the rotating portion;
A valve overlap control means for controlling the valve overlap period by changing the operation timing of the intake valve or the exhaust valve,
The valve overlap control means shortens the valve overlap period when the electric motor is operating, compared to when the electric motor does not operate and is supercharged by the supercharger. A control device for an internal combustion engine having a supercharger with an electric motor. In the control apparatus for an internal combustion engine having the supercharger with an electric motor according to claim 1,
The valve overlap control means controls the internal combustion engine having a supercharger with an electric motor when the output of the electric motor is large and shortens the valve overlap period as compared with a case where the output is small. apparatus. In the control apparatus for an internal combustion engine having the supercharger with an electric motor according to claim 2,
An external EGR passage for circulating a part of the exhaust gas to the intake passage;
An external EGR valve that opens and closes the external EGR passage;
External EGR valve opening that increases the opening of the external EGR valve when the motor is operating and when the motor does not operate and is supercharged by the supercharger And a control means for an internal combustion engine having a supercharger with an electric motor. A control device for an internal combustion engine having a supercharger with an electric motor,
A supercharger having a rotating portion of a compressor provided in an intake passage of the internal combustion engine, and an electric motor capable of driving the rotating portion;
An ignition timing control means for advancing the ignition timing when the electric motor is operating as compared to when the electric motor is not operating and is supercharged by the supercharger; A control apparatus for an internal combustion engine having a supercharger with an electric motor. In the control apparatus of the internal combustion engine having the supercharger with electric motor according to claim 4,
The control device for an internal combustion engine having a supercharger with an electric motor, wherein the ignition timing control means advances the ignition timing when the output of the electric motor is large as compared with a case where the output is small.

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