JP2003239754A - Supercharging pressure control device - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide an electric motor turbocharger having an electric motor that rotationally drives a turbine of a turbocharger, to correct the supply power for controlling the electric motor by learning, and to always optimize the supercharging. Provided is a supercharging pressure control device capable of performing pressure control. SOLUTION: A supercharging pressure control device according to the present invention includes an electric motor 11b capable of changing a supercharging pressure by rotating a compressor 11a of a turbocharger 11, and a target supercharging pressure determining means 16.
And a supercharging pressure detecting means 19 for detecting an actual supercharging pressure, and a control for the electric motor 11b based on a predetermined power determination criterion that defines a relation between a target supercharging pressure, an actual supercharging pressure and power supplied to the motor 11b. There is provided a supply power determining means 16 for determining the supply power, and a learning correction means 16 for learning the actual supercharging pressure variation with respect to the supply power to the electric motor 11b and correcting the power determination reference of the supply power determination means 16. It is characterized by:

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supercharging pressure control device for controlling a supercharging pressure by using a turbocharger with an electric motor in which a compressor of a turbocharger can be driven by an electric motor.

[0002]

2. Description of the Related Art An attempt to obtain a high output (or low fuel consumption) by supercharging the intake air amount of an engine (internal combustion engine) with a turbocharger has been in common use. One of the demands for improvement of the turbocharger is that the boost pressure rise in the low speed range is poor and the engine output characteristics in the low speed range are not good. This is a phenomenon that occurs in a low rotation speed range where exhaust energy is low, based on the principle of a turbocharger that uses intake energy to supercharge intake air. In order to improve this, a twin turbo system is generally used, but an attempt is made to incorporate a motor into the turbine / compressor and forcibly drive the turbine / compressor to obtain a desired boost pressure. Attempts have also been made. In such a case, it is possible to cause the electric motor to perform regenerative power generation using the exhaust energy. An example of such a turbocharger with an electric motor is described in Japanese Patent Application Laid-Open No. 8-182382.

[0003]

The characteristics of turbochargers with electric motors vary due to the difference in performance among individual electric motors and environmental differences such as temperature. It is sufficient that the initial performance difference for each individual be corrected once, but it is also necessary to respond to changes in characteristics due to aging. Further, variations in characteristics due to environmental differences do not have to be corrected only once because the environment such as temperature changes. Due to such a characteristic difference, even if the same electric power is applied, the output of the electric motor is not constant and the same supercharging assist amount cannot be obtained in many cases. Even in the turbocharger with an electric motor described in the above-mentioned publication, no consideration is given to such a point.

Therefore, an object of the present invention is, in an electric motor turbocharger having an electric motor that rotationally drives a turbine of a turbocharger, corrects electric power supplied for controlling the electric motor by learning and always performs optimum supercharging pressure control. It is an object of the present invention to provide a supercharging pressure control device capable of performing the above.

[0005]

According to a first aspect of the present invention, there is provided a supercharging pressure control device, wherein a turbocharger compressor is rotated to change the supercharging pressure and a target supercharging pressure is determined. Pressure determining means, a power supply determining means for determining the power supplied to the electric motor based on a predetermined power determining standard that defines the relationship between the target supercharging pressure and the power supplied to the electric motor, and an actual power detecting means for detecting the actual supercharging pressure. It is characterized by comprising supercharging pressure detecting means and learning correction means for learning the actual supercharging pressure fluctuation with respect to the electric power supplied to the electric motor and correcting the electric power determination standard of the electric power supply determining means.

According to a second aspect of the present invention, in the supercharging pressure control device according to the first aspect, the learning correction means sets the frequency at which the difference between the target supercharging pressure and the actual supercharging pressure falls outside the predetermined range. It is characterized in that the power determination standard of the supply power determining means is corrected when the power is above a predetermined level.

According to a third aspect of the present invention, in the supercharging pressure control device according to the first or second aspect, the learning correction means is
It is characterized in that the power determination reference of the supply power determining means is corrected only when the frequency at which the difference between the target supercharging pressure and the actual supercharging pressure is out of the predetermined range is not less than the predetermined value within the predetermined continuous period.

According to a fourth aspect of the present invention, in the supercharging pressure control device according to any one of the first to third aspects, the supply power determining means determines the difference between the target supercharging pressure and the actual supercharging pressure. The power supply to the electric motor is determined based on a predetermined power determination standard.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the supercharging pressure control device of the present invention will be described below. An engine 1 having a supercharging pressure control device of this embodiment is shown in FIG.

The term "supercharging pressure" may be used as a term indicating a differential pressure with respect to atmospheric pressure.
On the other hand, the term "supercharging pressure" may be used as a term indicating the absolute pressure in the intake pipe. In the following, when it is necessary to clearly explain the two, the points will be clarified. For example, when performing supercharging pressure control based on the output of the pressure sensor that detects the pressure in the intake pipe,
If this pressure sensor detects a differential pressure with respect to atmospheric pressure, the boost pressure control can be easily controlled based on the boost pressure as a difference with respect to atmospheric pressure, and the pressure sensor detects absolute pressure. If it is a sensor, it is easy to control the supercharging pressure based on the intake pressure as an absolute pressure.

The engine 1 described in this embodiment is a multi-cylinder engine, but only one of the cylinders is shown in FIG. 1 as a sectional view. The engine 1 is an engine of a type in which fuel is injected by an injector 2 onto the upper surface of a piston 4 in a cylinder 3. The engine 1 is capable of stratified combustion and is a so-called lean burn engine. By supercharging more intake air and performing lean burn by a turbocharger described later, not only high output but also low fuel consumption can be realized.

In the engine 1, the air sucked into the cylinder 3 through the intake passage 5 is compressed by the piston 4, and the fuel is injected into the recess formed in the upper surface of the piston 4 to inject a rich mixture into the spark plug. It is collected in the vicinity of 7, and is ignited by the spark plug 7 and burned. An intake valve 8 opens and closes the inside of the cylinder 3 and the intake passage 5.
The exhaust gas after combustion is exhausted to the exhaust passage 6. An exhaust valve 9 opens and closes the inside of the cylinder 3 and the exhaust passage 6. On the intake passage 5, from the upstream side, the air cleaner 10, the turbo unit 11, the intercooler 12,
A throttle valve 13 and the like are arranged.

The air cleaner 10 is a filter for removing dust and dirt from the intake air. Turbo unit 11
Is disposed between the intake passage 5 and the exhaust passage 6 to perform supercharging. In the turbo unit 11 of the present embodiment, the turbine-side impeller and the compressor-side impeller are connected by a rotating shaft (hereinafter, this portion will be simply referred to as turbine / compressor 11a). Further, the turbocharger of the present embodiment uses the electric motor 1 so that the rotating shaft of the turbine / compressor 11a serves as the output shaft.
1b is a turbocharger with an electric motor incorporated therein. The electric motor 11b is an AC motor and can also function as a generator. The turbo unit 11 can also function as a normal supercharger that supercharges only by the exhaust energy, but the turbine / compressor 1 is operated by the electric motor 11b.
Further supercharging can be performed by forcibly driving 1a.

It is also possible to utilize the exhaust energy to regenerate electric power by rotating the electric motor 11b via the turbine / compressor 11a and recover the generated electric power. Although not shown, the electric motor 11b has a rotor fixed to the rotating shaft of the turbine / compressor 11a and a stator arranged around the rotor as main components. Turbo unit 1 on intake passage 5
An air-cooling intercooler 12 that lowers the temperature of intake air that has increased in temperature due to pressure increase due to supercharging by the turbo unit 11 is disposed on the downstream side of 1. The intercooler 12 lowers the temperature of the intake air and improves the charging efficiency.

A throttle valve 13 for adjusting the amount of intake air is arranged downstream of the intercooler 12. The throttle valve 13 of the present embodiment is a so-called electronically controlled throttle valve, and includes an accelerator pedal 14
Is detected by the accelerator positioning sensor 15, and the ECU 16 is detected based on the detection result and other information amount.
Determines the opening of the throttle valve 13.
The throttle valve 13 is opened / closed by a throttle motor 17 arranged in association therewith. A throttle positioning sensor 18 for detecting the opening of the throttle valve 13 is also provided.

A pressure sensor 19 for detecting the pressure in the intake passage 5 (intake pressure) is arranged downstream of the throttle valve 13. These sensors 15, 18, 19 are E
It is connected to the CU16, and the detection result is connected to the ECU16.
Have been sent to. The ECU 16 includes a CPU, ROM, RA
It is an electronic control unit composed of M and the like. The injector 2, the ignition plug 7, the electric motor 11b, and the like described above are connected to the ECU 16, and these are controlled by a signal from the ECU 16. In addition to the above, the ECU 16 is also connected to the hydraulic pressure of the variable valve timing mechanism 20 that controls the opening / closing timing of the intake valve 8, the controller 21 connected to the electric motor 11b, the battery 22, and the like.

The controller 21 not only controls the drive of the electric motor 11b, but also has a function as an inverter for converting the voltage of the electric power regenerated by the electric motor 11b. The electric power generated by the regenerative electric power is converted into a voltage by the controller 21 and then charged in the battery 22.

On the other hand, an exhaust gas purification catalyst 23 for purifying exhaust gas is mounted on the exhaust passage 6 on the downstream side of the turbo unit 11. Then, an EGR (Exhaust Gas Recirculatio) for recirculating the exhaust gas from the exhaust passage 6 (upstream of the turbo unit 11) to the intake passage 5 (surge tank formed on the downstream side of the pressure sensor 19).
n) A passage 24 is provided. On the EGR passage 24,
An EGR valve 25 for adjusting the exhaust gas recirculation amount is attached. The opening control of the EGR valve 25 is also the above-mentioned E
It is performed by CU16.

A rotation speed sensor 26 for detecting the engine rotation speed is attached near the crankshaft of the engine 1. Further, although not shown, the turbo unit 11 of this embodiment is also a so-called variable nozzle turbo. The variable nozzle turbo has a plurality of movable vanes disposed in a nozzle portion located outside the turbine / compressor 11a on the exhaust side, and variably controls an exhaust flow rate flowing from the turbine nozzle toward the turbine / compressor 11a. . The supercharging pressure can be changed by controlling the variable nozzle.

The actuator for driving the variable nozzle is connected to the ECU 16 and is controlled by the ECU 16. This variable nozzle mechanism functions as a supercharging pressure changing means other than the electric motor 11b. Other than the electric motor 11b, examples of the supercharging pressure control means that can be used include the variable nozzle mechanism described here and a mechanism that variably controls the turbine capacity (A / R variable mechanism). Further, the ECU 16 functions as a target supercharging pressure determining unit, a supply power determining unit, and a learning correction unit. Further, the pressure sensor 19 functions as an actual boost pressure detecting means.

Further, although not shown, the exhaust passage 6
A flow path that bypasses the turbo unit 11 is also provided above, and a waste gate valve is arranged on this flow path. The waste gate valve opens when the boost pressure exceeds a predetermined pressure, and the turbine / compressor 11
The supercharging pressure is controlled by reducing the exhaust flow rate to a. Although the waste gate valve of this embodiment is a passive valve that opens and closes by using intake pressure, a solenoid valve or the like may be used to actively control the opening and closing by the ECU 16. In such a case, it can be one of the means (supercharging pressure control means) for positively controlling the supercharging pressure.

The basic part of the supercharging pressure control using the above-mentioned electric motor 11b will be described. FIG. 2 shows a flowchart of the basic part of control. The control of the flowchart shown in FIG. 2 is repeatedly executed every predetermined time (for example, every 32 ms).

First, the engine speed is the speed sensor 26.
And the engine load is estimated from the intake air amount (estimated by the pressure sensor 19) and the throttle opening (detected by the throttle positioning sensor 18) (step 200). Next, the base target boost pressure B is calculated from the engine speed and the engine load (step 205). The base target supercharging pressure B is a supercharging pressure expected at a predetermined engine speed and a predetermined engine load during steady operation, and is acquired in advance by experiments or the like and stored as a map in the ROM in the ECU 16. ing. The control of the variable nozzle described above is performed based on this base target boost pressure B.

Next, the engine rotational speed detected by the rotational speed sensor 26 and the accelerator positioning sensor 15
The supercharging pressure P to be increased by the electric motor 11b is determined based on the accelerator opening detected by (step 210). The relationship between the engine speed, the accelerator opening, and the boost pressure P for raising the height has been determined in advance through experiments and the like, and is a ROM in the ECU 16 as a map.
It is stored in. This map is shown in FIG. As shown in FIG. 3, here, a region in which the engine speed is equal to or lower than a predetermined speed and the accelerator opening is equal to or higher than a predetermined opening is set as a specific operation region, and the state of the engine 1 is Only when operating within a specific operating area,
The above-mentioned raised supercharging pressure P is set as a positive value, and the electric motor 11b assists. Even in the specific operation region, the boost supercharging pressure P becomes larger as the rotation speed becomes lower and the accelerator opening becomes larger.

When the state of the engine 1 is outside the specific operating range, the above-mentioned raised supercharging pressure P is set to a negative value instead of 0, so that the assist by the electric motor 11b is substantially prohibited. Has been done. The meaning of setting the raised supercharging pressure P as a negative value will be described later. After step 210, the target supercharging pressure B is calculated by adding the supercharging pressure P for raising the electric motor 11b to the base target supercharging pressure B (step 210). The target supercharging pressure T is a control target value set for supercharging control by the electric motor 11b, and may not match the supercharging pressure originally desired.

For example, as can be seen from the map in FIG.
When the accelerator opening is large at low speed, the amount of increase P
Is set large, and the target supercharging pressure T is set large.
However, the target supercharging pressure T at this time may be a supercharging pressure that cannot be actually achieved. By setting the target supercharging pressure T in this way, it is possible to ensure that the full assist of the supercharging pressure by the electric motor 11b is continuously performed. In particular, when the raised amount P is set to be positive, that is,
In a situation in which it is considered that the supercharging by the electric motor 11b should be positively performed, the target supercharging pressure T is set to be slightly larger than the supercharging pressure which is originally desired, via the raised amount P. The supercharging by 11b is ensured.

After step 21, the pressure sensor 19 detects the pressure in the intake pipe as the actual supercharging pressure C (step 2
20), The difference ΔP between the target boost pressure T and the detected actual boost pressure C is calculated (step 225). Next, it is judged whether or not the calculated difference ΔP is larger than 0 (step 2
30) If the difference ΔP is less than or equal to 0, the assist flag Fassist indicating whether or not the electric motor 11b assists is set to 0, and the flow chart of FIG. 2 is temporarily exited without supercharging assist by the electric motor 11b. Here, even if the above-mentioned raised supercharging amount P is a positive value, if the difference ΔP is 0 or less, supercharging by the electric motor 11b is not performed. On the other hand, if step 230 is affirmative, that is, if the difference ΔP is larger than 0, the instruction value for performing the supercharging assist by the electric motor 11b is determined based on the difference ΔP, and this command value is given to the controller 21. And output (step 235).

FIG. 4 shows the relationship between the difference ΔP and the command value given to the controller 21. As shown by the solid line in FIG.
The command value to the controller 21 is a voltage value. The larger the difference ΔP, the larger the voltage value sent to the controller 21. The range of the voltage value is 0 to 4.3V here. When the voltage of 4.3 V is sent to the controller 21, the controller 21 fully drives the electric motor 11b to fully assist the supercharging. After sending the instruction value to the controller 21, the assist flag Fass
ist is set to 1 (step 240), and the controller 21
The electric motor 11b is controlled based on the instruction value received by (step 245).

In this embodiment, the controller 21 supplies the electric current determined based on the given instruction value to the electric motor 11
It is sent to b. The electric motor 11b changes the output torque according to the applied current, and is controlled via the current to be sent. It should be noted that in the present embodiment, only the electric current based on the instruction value is given to the electric motor 11b, and the feedback control of the electric motor 11b is not performed.
After that, the current value given to the electric motor 11b is changed by repeating the control of the flowchart of FIG. However, feedback control of the electric motor 11b may be performed, for example, a rotation speed sensor may be provided in the turbine / compressor 11a, and feedback control of current supplied to the electric motor 11b may be performed based on the turbine rotation speed.

By supercharging by the electric motor 11b in this manner, the shortage of the supercharging pressure in the low rotation speed range is compensated to improve the rising of the supercharging pressure, and the turbo unit can achieve high output or high efficiency at low rotation speed. It becomes possible to obtain from the range to the high rotation range. Then, here, the supercharging pressure control by the variable nozzle mechanism is performed with priority over the supercharging pressure control by the electric motor 11b. For this reason,
Since the priority is set for the two boost pressure controls, both boost pressure controls do not interfere with each other, and stable boost pressure control can be performed.

Further, here, the variable nozzle mechanism is controlled on the basis of the base target supercharging pressure B, while the electric motor 11b is not the base target supercharging pressure B, but the supercharging pressure P for raising it. It is controlled based on the added target supercharging pressure T. In this way, each control has a different target (control map). Therefore, even if the assist by the electric motor 11b becomes excessive, another supercharging pressure control that is independent from this does not stop working. Are less likely to interfere. Note that the supercharging pressure control by the variable nozzle mechanism in the present embodiment is P from the relationship with the actual supercharging pressure C.
Known supercharging pressure control such as ID feedback control is performed.

Further, as described above, here, the boosted supercharging amount P is set as a negative value outside the specific operation range. By doing so, the calculated target supercharging pressure T is calculated to be smaller, and as a result, the difference ΔP is also calculated to be smaller. Electric motor 11b
Whether or not to perform the supercharging pressure control based on the difference ΔP is determined based on the magnitude of the difference ΔP. Therefore, the fact that the difference ΔP is calculated to be smaller means that the supercharging pressure control by the electric motor 11b is less likely to be performed. become. The difference ΔP is the difference between the actual supercharging pressure C and the target supercharging pressure T that is calculated to be small, so that the actual supercharging pressure is eventually determined when determining whether or not the supercharging pressure control by the electric motor 11b is necessary. A certain degree of variation with respect to C will be secured.

In this way, when it is not desired to start the assist by the electric motor 11b, such as when the actual supercharging pressure C fluctuates due to a disturbance or the like, it becomes difficult to perform the supercharging pressure by the electric motor 11b. The supercharging pressure control can be stably performed. For example, when the actual supercharging pressure C fluctuates by repeating a slight increase or decrease due to a disturbance or the like, the electric motor 11b
If the start and stop of the supercharging due to is frequently repeated, the supercharging pressure control becomes rather rough. That is, the electric motor 11b
Unnecessary supercharging pressure control will be performed. Therefore, when it seems that supercharging by the electric motor 11b is not necessary (outside the specific operation region), it is made difficult to start supercharging by the electric motor 11b to stabilize the supercharging pressure control. .

Furthermore, if the electric motor 11b is used as a generator, it is possible to recover electric energy.
While the electric power is being recovered from the electric motor 11b, the electric motor 11
b suppresses the rotation of the turbine / compressor 11a. That is, the electric motor 11b not only consumes electric energy to increase the rotation speed of the turbine / compressor 11a, but also regenerates power to suppress the rotation of the turbine / compressor 11a.
The control range of the rotation control (supercharging pressure control) of the turbine / compressor 11a by the electric motor 11b is wide. The electric motor 1
When 1b is not rotationally driven and is not performing regenerative power generation (not connected to the battery 22),
The turbine / compressor 11a is rotated only by the exhaust energy. In this case, the electric motor 11
b does not prevent the turbine / compressor 11a from rotating (cogging torque is negligibly small).

Next, the control for correcting / learning the above-mentioned basic supercharging pressure control will be described.

As described above, the characteristics of the electric motor 11b vary due to the difference in performance and the difference in environment such as temperature. By correcting and learning this, it becomes possible to perform more accurate supercharging pressure control. A flowchart of the control described here is shown in FIG. The control of the flowchart shown in FIG. 5 is also repeatedly executed at the same predetermined intervals (for example, every 32 ms) in parallel with the control of the flowchart of FIG. This control determines whether the basic control that is repeatedly performed tends to control the supercharging pressure to a lower level or to control the supercharging pressure to a higher level.

If any of the tendencies occurs at a predetermined frequency, the boost pressure is corrected in the control being executed. If the same tendency still continues and a further predetermined frequency is reached, the reference itself for driving the electric motor 11b is corrected through this learning. As shown in FIG. 5, first, whether the motor assist flag Fassist is 1 or not,
That is, it is determined whether or not the supercharging pressure control by the electric motor 11b is being performed at that time (step 500). The motor assist flag Fassist is set during the basic control of boost pressure shown in FIG. 2 (steps 240 and 25 in FIG. 2).
0). Since the tendency of the supercharging pressure control by the electric motor 11b is observed, when the step 500 is denied, the flow chart shown in FIG. 5 is left as it is.

On the other hand, when step 500 is affirmative and the supercharging pressure control by the electric motor 11b is being performed, it is judged whether or not the difference ΔP at that time is larger than a predetermined value α (for example, 10 [kPa]). (Step 505). Difference ΔP
2 is held / updated in the memory in the ECU 16 every time it is calculated in step 225 of the flowchart of FIG. 2, so this value is read and judged. Since the difference ΔP indicates how much the target supercharging pressure T and the actual supercharging pressure C deviate from each other, the affirmative determination in Step 505 means that the target supercharging pressure T is actually supercharged. It means that the pressure C tends to be too low (the target is not easily reached). In this case, the counter Cb is first cleared (step 51
0), the counter Ca is incremented by +1 (step 515).

The counter Ca is a counter for counting the frequency at which the actual supercharging pressure C is too low with respect to the target supercharging pressure T, and the counter Cb is the actual supercharging pressure with respect to the target supercharging pressure T. This is a counter for counting the frequency at which the supply pressure C is too high. In step 510, since the actual supercharging pressure C is too low with respect to the target supercharging pressure T, the actual supercharging pressure C is counted up under the situation where the actual supercharging pressure C is too high with respect to the target supercharging pressure T before that. The existing counter Cb has been cleared because the situation has changed.

After step 515, it is determined whether the actual supercharging pressure C is too low with respect to the target supercharging pressure T at a high frequency, based on whether the counter Ca is larger than 40 (step). 520). If step 520 is denied,
For the time being, only by counting up the counter Ca in step 515, the flow chart of FIG. 5 is temporarily exited. However, if step 520 is affirmative, it can be determined that the actual supercharging pressure C tends to be lower than the target supercharging pressure T in the supercharging pressure control shown in FIG. 2, that is,
It can be judged that the supercharging by the electric motor 11b is not effective than expected.

In such a case, the command voltage to the controller 21 determined by the supercharging pressure control shown in FIG. 2 is increased, that is, the electric power supplied to the electric motor 11b is increased to improve the supercharging effect of the electric motor 11b. Correction for enhancement is performed (step 525). Here, a correction of +0.1 [V] is applied. Since the command voltage value to the controller 21 is between 0 and 4.3 V as described above, it is determined whether the corrected command voltage is greater than 4.3 [V] (step 530). If it is larger, the upper limit is guarded by setting it to 4.3 [V] (step 535).

Thus, even if the command voltage value to the controller 21 determined during the supercharging pressure control is corrected, the actual supercharging pressure C tends to be lower than the target supercharging pressure T. Then, the counter Ca keeps counting up. Following steps 530 and 535, the counter Ca is 100.
Is determined (step 540), and it is determined whether or not the situation is not improved even if the correction is performed in this way. If step 540 is denied (while the counter Ca is greater than 40 and 99 or less), it is not possible to determine that the situation is still improved even if the correction is performed, and the process in FIG. 5 is temporarily exited. .

However, if step 540 is affirmed (the counter Ca has reached 100), the controller 2 determined in the supercharging pressure control as described above.
It is determined that the correction of the command voltage value to 1 is not sufficient, and the reference itself for determining the command voltage value to the controller 21 is corrected (step 545). This is said to be corrected based on learning here.

Specifically, the relationship between the difference ΔP shown in FIG. 4 and the command voltage value to the controller 21 is shown by a solid line to a dotted line (A) in FIG. Correct so that the effect is remarkable. Dotted line (A)
In the graph shown by, a part of the solid line is translated upward by a predetermined voltage (however, the upper limit is 4.3 V). After step 545, since the reference itself has been corrected based on the learning, the counter C is newly added to see the tendency of the boost pressure control.
After clearing a, the flow chart shown in FIG. 5 is exited.

On the other hand, when step 505 is denied, the difference ΔP at that time is the predetermined value β (for example, 5).
[KPa]) is determined (step 5
55). Contrary to the above-mentioned situation, the affirmative of step 555 means that the actual supercharging pressure C is too close to the target supercharging pressure T (the supercharging effect by the electric motor 11b is too effective). It means that there is a tendency. As described above, the target supercharging pressure T set here for supercharging by the electric motor 11b is set to be slightly larger, so the actual supercharging pressure C becomes the target supercharging pressure T. It can be determined that the motors 11b are too close to each other because the supercharging effect by the electric motor 11b is too effective. That is, steps 505 and 55
When both 5 are denied (β ≦ ΔP ≦ α), it can be determined that the supercharging by the electric motor 11b is appropriately performed.

Therefore, if step 555 is positive, the counter Ca is first cleared (step 56).
0), the counter Cb is incremented by +1 (step 565). The subsequent steps are similar to steps 510 to 550 described above except that the tendency is reversed, and therefore only a brief description will be given. After step 565, the target boost pressure T
On the other hand, the actual supercharging pressure C is close, and it is determined whether the frequency of the situation where the supercharging effect by the electric motor 11b is too strong is high or not depending on whether the counter Cb is greater than 20 (step 570). ). When step 570 is denied, the flow chart of FIG. 5 is temporarily exited. But step 5
When 70 is affirmed, it can be determined that the situation where the supercharging effect by the electric motor 11b is too effective continues.

In such a case, the command voltage to the controller 21 is reduced, that is, the electric power supplied to the electric motor 11b is reduced to correct the supercharging effect of the electric motor 11b (step 575). Here, -0.02
[V] is being corrected. Note that it is determined whether the corrected instruction voltage is smaller than 0 [V] (step 58).
0), and if smaller than 0 [V] (step 585), the lower limit is guarded. Step 580,
Subsequent to 585, it is determined whether or not the counter Cb has reached 100 (step 590), and it is determined whether or not the situation is not improved even if the correction is performed in this way.

If step 590 is denied (while the counter Cb is greater than 20 and less than or equal to 99), it cannot be determined that the situation is still improved even if the correction is performed, and the flowchart of FIG. Exit once. However, if step 590 is affirmative (counter Cb has reached 100), it is not sufficient to correct the command voltage value to the controller 21 determined during the supercharging pressure control. It is determined and the reference itself for determining the command voltage value to the controller 21 is corrected (step 595).

Specifically, the relationship between the difference ΔP shown in FIG. 4 and the command voltage value to the controller 21 is shown by a solid line to a dotted line (B) in FIG. Correct so that the effect is suppressed. Dotted line (B)
In the graph shown by, a part of the solid line is translated downward by a predetermined voltage (however, the upper limit finally reaches 4.3 V). After step 595, the counter Cb is cleared to newly see the tendency of the supercharging pressure control, and the flow chart shown in FIG. 5 is temporarily exited.

If step 555 is denied,
That is, when the difference ΔP is within the predetermined range (predetermined value β ≦ ΔP ≦ predetermined value α), it can be determined that the effect of the supercharging pressure control in the flowchart of FIG. The flowchart shown in 5 is exited. As described above, by correcting the reference itself for determining the electric power supplied to the electric motor through learning, it is possible to always perform optimum supercharging pressure control.

In particular, as described above, only when the frequency at which the difference between the target supercharging pressure and the actual supercharging pressure is out of the predetermined range is not less than the predetermined value (particularly, when the difference is not less than the predetermined value in the predetermined continuous period) It is possible to suppress the deterioration of the control accuracy due to unnecessary learning correction.

The present invention is not limited to the above embodiment. In the above-described embodiment, the supercharging pressure control device of the present invention is applied to the direct injection gasoline engine, but it may be applied to a non-direct injection gasoline engine, a diesel engine, or the like. Further, the supercharging pressure determining means, the supplied power determining means, etc. do not have to be configured by a single component, but a plurality of components (for example, E
CU, actuator, sensor, etc.).

Further, in the above-described embodiment, the turbine-side impeller and the compressor-side impeller are integrated by the rotating shaft, and both are necessarily rotated integrally. However, the present invention can be applied to, for example, a turbocharger having a turbine / compressor in which a clutch is arranged in the middle of a rotating shaft. In this case, the rotary shaft on the compressor side is in a state of being rotationally driven by the electric motor when supercharging is performed by the electric motor, and the rotary shaft on the turbine side and the electric motor are connected when regenerative power generation is performed by the electric motor. ing. Alternatively, a mode in which an electric motor for rotationally driving a turbine and an electric motor for rotationally driving a compressor are provided side by side can be considered.

Further, in the above-mentioned embodiment, the throttle valve 13 is an electronically controlled throttle valve,
The throttle valve is not necessarily electronically controlled, and may be a throttle valve of another form such as a normal throttle valve connected to the accelerator pedal by a wire. Furthermore, although the turbocharger has the variable nozzle mechanism in the above embodiment, it does not necessarily have to have such a mechanism.

[0055]

According to the boost pressure control device of the present invention, the optimum boost pressure control can always be performed by correcting the reference itself for determining the electric power supplied to the electric motor through learning. it can.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of an engine having a supercharging pressure control device of the present invention.

FIG. 2 is a flowchart showing basic control of supercharging pressure control.

FIG. 3 is a map for determining a boost pressure boost amount by an electric motor.

FIG. 4 is a map for determining an instruction value for a controller of an electric motor.

FIG. 5 is a flowchart showing learning correction control.

[Explanation of symbols]

1 ... Engine, 2 ... Injector, 3 ... Cylinder, 4 ...
Piston, 5 ... Intake passage, 6 ... Exhaust passage, 7 ... Spark plug, 8 ... Intake valve, 9 ... Exhaust valve, 10 ... Air cleaner, 11 ... Turbo unit, 11a ... Turbine, 11
b ... Electric motor, 12 ... Intercooler, 13 ... Air cleaner, 13 ... Throttle valve, 14 ... Accelerator pedal, 15 ... Accelerator positioning sensor, 16 ... EC
U, 17 ... Throttle motor, 18 ... Throttle positioning sensor, 19 ... Pressure sensor, 20 ... Variable valve timing mechanism, 21 ... Controller, 22 ... Battery, 23 ... Exhaust gas purification catalyst, 24 ... EGR passage, 25 ... E
GR valve, 26 ... Revolution sensor.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02D 23/00 F02D 23/00 N F02B 37/12 301Z (72) Inventor Osamu Igarashi Toyota Town, Aichi Prefecture 1st in Toyota Motor Corporation (72) Inventor Hironari Hashimoto 1st Toyota Town in Toyota City, Aichi Prefecture 1st Toyota Motor Corporation (72) Inventor Chika Kamiwa 1st Town in Toyota City, Aichi Toyota Motor Corporation F-term (reference) 3G005 EA04 EA16 EA20 FA06 GA00 GA04 GD14 GD17 GE03 GE09 JA02 JA06 JA24 JA39 JA40 JA45 JB02 JB25 3G092 AA01 AA06 AA09 AA18 BA02 DB03 DB04 DC03 DG08 EA09 EC01 EC05 FA48ZXHA16 HE01 HA16

Claims (4)

[Claims] 1. A motor capable of changing a supercharging pressure by rotating a compressor of a turbocharger, a target supercharging pressure determining means for deciding a target supercharging pressure, a target supercharging pressure and an electric power supplied to the electric motor. Supply power determination means for determining the supply power to the electric motor based on a predetermined electric power determination criterion that defines the relationship, actual supercharging pressure detection means for detecting the actual supercharging pressure, and actual for the electric power supplied to the electric motor. And a learning correction unit that corrects the power determination reference of the supplied power determination unit by learning the supercharging pressure fluctuation of the above. 2. The learning correction means corrects the power determination reference of the supply power determination means when the frequency at which the difference between the target boost pressure and the actual boost pressure is out of a predetermined range is a predetermined value or more. The supercharging pressure control device according to claim 1, which is characterized in that. 3. The learned correction means determines the power of the supplied power determination means only when the frequency at which the difference between the target supercharging pressure and the actual supercharging pressure is out of a predetermined range is a predetermined value or more within a predetermined continuous period. The supercharging pressure control device according to claim 1, wherein the reference is corrected. 4. The supply power determining means determines the supply power to the electric motor based on a difference between the target boost pressure and the actual boost pressure and a predetermined power determination standard. The supercharging pressure control device according to any one of 1 to 3.