JP2003269180A - Boost control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a boost control device with a motor for driving/rotating a compressor of a turbo-charger, capable of achieving an excellent output characteristic and driving feeling. <P>SOLUTION: The boost control device comprises the motor 11b capable of changing the boost pressure by rotating the compressor 11a of the turbo- charger 11, motor control means 16 and 21 for controlling the motor 11b, a situation determining means 16 for determining whether the motor 11b should be stopped or not, and an estimation means 16 for estimating whether the pressure-charging by the motor 11b will be necessary or not after a prescribed period of time elapses. When the estimation means 16 estimates that the pressure-charging by the motor 11b will be necessary after the prescribed period of time elapses, the motor control means 16 and 21 compulsorily controls the motor 11b to perform the pressure-charging even if the situation determining means 16 determines that the motor should be stopped. <P>COPYRIGHT: (C)2003,JPO

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. However, by incorporating an electric motor in the turbine / compressor to 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. As such a turbocharger with an electric motor, Japanese Patent Laid-Open No. 8-
There is one described in Japanese Patent No. 182382.

[0004]

In the turbocharger with electric motor described in the above publication, the actual supercharging pressure is compared with the target supercharging pressure to control the electric motor. When the supply pressure is reached, supercharging by the electric motor is stopped. However, immediately after that, when supercharging by the electric motor is required again, the rotation speed of the turbine / compressor is reduced, and therefore the supercharging pressure of the conventional supercharger is slightly smaller than that of the turbocharger without the electric motor. It takes time to rise. The present invention has been made to eliminate this slight turbo lag and further improve the output characteristics and the driving feeling.

Therefore, an object of the present invention is to provide a supercharging pressure control device capable of realizing good output characteristics and driving feeling in a supercharging pressure control device having an electric motor for rotationally driving a compressor of a turbocharger. To do.

[0006]

According to a first aspect of the present invention, there is provided a supercharging pressure control device, which is capable of changing a supercharging pressure by rotating a compressor of a turbocharger provided in association with an internal combustion engine. An electric motor control unit for controlling the electric motor, a condition judgment unit for judging whether or not the electric motor should be stopped, and a prediction unit for predicting necessity of supercharging by the electric motor after a predetermined time are provided. The motor control means is
When the predicting unit predicts that the electric motor needs to be supercharged after a predetermined time, the electric motor is forced to be supercharged even if the situation determining unit determines that the electric motor should be stopped. It is characterized by performing.

According to a second aspect of the present invention, in the supercharging pressure control device according to the first aspect, the actual supercharging pressure detecting means for detecting the actual supercharging pressure and the target supercharging pressure for calculating the target supercharging pressure. The electric motor control means further controls the electric motor based on the actual supercharging pressure detected by the actual supercharging pressure detecting means and the target supercharging pressure calculated by the target supercharging pressure calculating means. However, the situation determination means is a situation where the electric motor should be stopped when the actual supercharging pressure detected by the actual supercharging pressure detecting means is higher than the target supercharging pressure calculated by the target supercharging pressure calculating means. It is characterized by determining that.

The invention described in claim 3 is the invention according to claim 1 or 2.
In the supercharging pressure control device described in (1), the predicting means determines that a certain period of time elapses after the end of the acceleration state is a state in which supercharging by the electric motor is required after a predetermined period of time. Note that the acceleration state includes both a state where the acceleration state is maintained to some extent and an acceleration state for a very short time.

According to a fourth aspect of the present invention, in the supercharging pressure control device according to any of the first to third aspects, a throttle valve for adjusting the intake air amount and an intake air amount control for controlling the throttle valve are provided. The situation determination means determines that the situation is such that the electric motor should be stopped when the opening of the throttle valve is limited to a predetermined opening or less, and the prediction means determines the throttle valve When the required output of the internal combustion engine becomes equal to or higher than a predetermined value while the opening degree is limited to the predetermined opening degree or less, it is determined that the electric motor needs to be supercharged after a predetermined time.

[0010]

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 engine 1 described in the present embodiment is a cylinder injection type gasoline engine, but can be applied to a gasoline engine of a type that injects fuel into the intake passage and a diesel engine.

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: supercharging pressure) is arranged downstream of the throttle valve 13. Here, the pressure sensor 19 functions as an actual boost pressure detecting means. These sensors 1
5, 18, and 19 are connected to the ECU 16 and send the detection result to the ECU 16. ECU16 is C
It is an electronic control unit composed of PU, ROM, RAM 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. EC
In addition to the above, U16 also includes a hydraulic control mechanism of a variable valve timing mechanism 20 for controlling the opening / closing timing of the intake valve 8 and a controller 2 connected to the electric motor 11b.
1, a battery 22 and the like are also connected.

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.

Further, 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. What is a variable nozzle turbo?
A plurality of movable vanes are arranged in a nozzle portion located outside the turbine / compressor 11a on the exhaust side to variably control the 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 means for changing the supercharging pressure other than the electric motor 11b. The ECU 16 functions as a target supercharging pressure calculation means, a situation determination means, and a prediction means. In addition, the ECU 16
Also functions as a motor control unit together with the controller 21 and the like. As a supercharging pressure control means other than the electric motor 11b, in addition to the variable nozzle mechanism described here, a mechanism for variably controlling the turbine capacity (A / R)
Variable mechanism) and the like.

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
a) The supercharging pressure is controlled by reducing the exhaust flow rate to the turbine side impeller.

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 that is the supercharging pressure changing means other than the electric motor 11b is performed based on the base target supercharging 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 zero. The meaning of setting the raised supercharging pressure P as a negative value will be described later. After step 210, the target target boost pressure B is added with the boost pressure P for raising the electric motor 11b.
(Step 215). Next, the pressure sensor 19 detects the intake pipe pressure as the actual supercharging pressure C (step 220), and calculates the difference ΔP between the target supercharging pressure T and the detected actual supercharging pressure C (step 225). .

It is judged whether or not the calculated difference ΔP is larger than 0 (step 230). If the difference ΔP is 0 or less,
The assist flag Fassist indicating whether or not the electric motor 11b is assisted is set to 0, and the flowchart of FIG. 2 is temporarily exited without performing the 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 in FIG. 4, the command value to the controller 21 is based on the voltage value. Difference Δ
The larger P is, the larger voltage value is sent to the controller 21. The range of the voltage value is 0 to
It is in the range of 4.3V. When a voltage of 4.3 V is sent to the controller 21, the controller 21 causes the motor 11b to
Is fully driven to fully assist supercharging. After sending the instruction value to the controller 21, the assist flag Fassist is set to 1 (step 240), and the electric motor 11b is controlled based on the instruction value received by the controller 21 (step 245).

In this embodiment, the controller 21 supplies a 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 speed region is compensated to improve the rise of the supercharging pressure, and the turbo unit can achieve high output or high efficiency at low speed. It becomes possible to obtain from the range to the high rotation range.

Further, as described above, here, the boost supercharging amount P is set as a negative value outside the specific operating 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. Since the difference ΔP is the difference between the target boost pressure T and the actual boost pressure C that are calculated to be smaller, the difference ΔP with respect to the actual boost pressure C is determined when determining whether or not the boost pressure control by the electric motor 11b is necessary. Therefore, a certain range of fluctuation will be secured.

With this arrangement, when it is not desired to start assisting by the electric motor 11b, such as when the actual supercharging pressure C fluctuates due to 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).

As can be seen from the basic control shown in the flow chart of FIG. 2, the actual boost pressure C is the target boost pressure T.
If it becomes above, supercharging by electric motor 11b will not be performed. However, when it is necessary to recharge the electric motor 11b again after a predetermined time, it is convenient not to stop the electric motor 11b immediately. When supercharging is performed from the state in which the turbine / compressor 11a is once stopped (or reduced in rotation speed), turbo lag is generated due to the increase in rotation of the turbine / compressor 11a even if assisted by the electric motor 11b. Although this turbo lag is very small compared to a normal turbocharger that rotates a turbine / compressor only with exhaust energy, it is not preferable from the viewpoint of improving output characteristics and operating feeling.

As a specific example of the case where re-driving is predicted after a predetermined time, the actual boost pressure C becomes larger than the target boost pressure T when the accelerator pedal is released during the acceleration state. In some cases, after the supercharging by the electric motor 11b is once stopped, the accelerator pedal is immediately stepped on again to re-accelerate. In this case, if only the above-mentioned basic control is performed, if the actual supercharging pressure C exceeds the target supercharging pressure T when the accelerator pedal is once returned, the electric motor 11b.
Drive will be stopped. After that, when the accelerator pedal is depressed again to perform the re-acceleration, the turbine / compressor 11a is rotated at a low speed, so that the above-mentioned turbo lag is generated.

When supercharging by the electric motor 11b is required after a predetermined time, it is preferable to drive the electric motor 11b so that the supercharging after the predetermined time is promptly performed. The purpose is to deal with such situations. As described above, in the case where the accelerator pedal is once returned at the time of acceleration and re-acceleration is performed, the drive of the electric motor 11b, which is normally driven already, should be continued under the situation where the electric motor 11b should be temporarily stopped. Become. The situation of this embodiment described below is also explained based on this situation. However, it may be determined that supercharging by the electric motor 11b is necessary after a predetermined time while the electric motor 11b is stopped. In such a case, the driving of the electric motor 11b is started in advance in preparation for the predetermined time.

As described above, the acceleration state includes not only the state in which the acceleration state is maintained to some extent, but also the acceleration state in a very short time. However, in the present embodiment, it is assumed that the electric motor 11b needs to be supercharged after a predetermined period of time, in particular, the predetermined period of time B after the acceleration state in which the former has continued for a certain period of time A is finished. Than after a very short acceleration
It can be said that there is a higher probability that recharging will be necessary after the acceleration has continued to some extent. When such a probability is higher, the drive of the electric motor 11b is maintained.

In addition, it is not preferable from the viewpoint of electric energy consumption that the motor 11b is forcibly driven for every very short period of time under the condition that it should be stopped. Therefore, here, the drive of the electric motor 11b is continued only when the probability is higher. It should be noted that, as the invention, the certain time after the acceleration state for a very short time may be determined to be the situation in which the supercharging by the electric motor 11b is necessary after the predetermined time.

Hereinafter, it is determined that the electric motor 11b needs to be supercharged after a predetermined time until the constant time B elapses after the acceleration state continued for the predetermined time A is completed, and the driving of the electric motor 11b is maintained. The case will be described. A flow chart of this control is shown in FIG. The control of the flow chart of FIG. 5 is executed in parallel with the control of the flow chart of FIG. 2, and the control result of the flow chart of FIG. 5 is prioritized when finally driving or stopping the electric motor 11b. .

First, based on the output of the pressure sensor 19,
It is determined whether the intake pipe internal pressure (supercharging pressure) is equal to or higher than a predetermined value (step 500). When step 500 is affirmed, it is then determined by the throttle positioning sensor 18 whether or not the throttle opening is equal to or larger than a predetermined value (step 505). Further, when step 505 is affirmed, it is determined by the accelerator positioning sensor 15 whether or not the accelerator opening is equal to or larger than a predetermined value (step 510). When step 510 is affirmed, that is, when all of steps 500 to 510 are affirmed, it can be determined that the vehicle is in the acceleration state, and at this time, the acceleration state flag is turned on (step 515).

On the other hand, if any of the steps 500 to 505 is denied, it can be judged that the vehicle is not in the accelerating state, and at this time, the accelerating state flag is turned off (step 52).
0). It is determined that the vehicle is in an accelerating state, and the acceleration state flag is set to O.
After step 515 that is set to N, the state of the acceleration state flag ON is monitored, and it is determined whether or not this state has passed a predetermined time A or more (step 525). Step 525
If affirmative, the acceleration state continues to some extent (for a certain period of time A), and there is a high probability that the motor 11b will be re-driven immediately even in a situation where it is stopped. For this reason, the drive continuation flag used to judge this probability is turned on (step 530).

After step 530, normal electric motor control is performed (step 535). If the process goes to step 535 after passing through step 530, it means that the vehicle is always in an accelerating state.
It seems that supercharging is often performed by the electric motor 11b. On the other hand, after step 520 or step 525
After is denied, it is determined whether the above-mentioned drive continuation flag is ON (step 540).

Immediately after passing through step 530 once, as shown in FIG.
If the acceleration state has already ended when the control of the flowchart of FIG. 5 is executed again, step 540 is affirmed after passing through step 520. If it is in the acceleration state but does not reach A for a certain period of time, step 52
After going through 5, step 540 is denied. If the acceleration state continues for a certain period of time A or more, step 540 is affirmed after passing through step 525. If it is not in the acceleration state and the drive continuation flag is not ON,
After passing through step 520, step 540 is denied.

If step 540 is denied, the drive continuation flag is OFF no matter what step is performed as described above, so it cannot be said that there is a high probability that the electric motor 11b will be immediately re-driven. Therefore, in this case, normal electric motor control is performed (step 5).
35). On the other hand, if step 540 is affirmed, it is next determined whether or not a certain time B has passed since the acceleration state flag was turned off (step 545). If step 545 is positive, the drive continuation flag is set to O.
Although it is N, a sufficient time (constant time B) has already passed since the end of the acceleration state, and it can be said that the above-mentioned probability is low. Therefore, if step 545 is positive, the drive continuation flag is changed to OFF (step 550).
After that, normal electric motor control is performed (step 53).
5).

On the other hand, if step 545 is denied, it means that the driving continuation flag is turned on, and the predetermined time B has not elapsed since the end of the acceleration state. In such a case, as described above, even if the driving by the electric motor 11b is originally stopped, it is highly likely that the electric motor 11b will be re-driven, so the driving is continued without stopping the electric motor 11b. That is, when step 545 is denied, the drive of the electric motor 11b is maintained without stopping and the throttle opening control is performed (step 555).

The throttle control performed here will be described. When step 555 is reached, it is often the case that the electric motor 11b is to be continued although it is in a situation where it should be stopped. Therefore, it is necessary to reduce the output of the engine 1 by the amount by which the electric motor 11b is continuously driven. Here, this is performed by the above-mentioned throttle opening control, and the actual boost pressure C is reduced by reducing the throttle opening.
Control so that. Note that, here, the output for adjusting the drive of the electric motor 11b is adjusted by controlling the opening degree of the throttle valve 13, but it is also possible to adjust the output by opening the waste gate valve described above. Alternatively, the output adjustment may be performed by the variable nozzle described above or a supercharging pressure changing unit other than the variable nozzle, for example, a mechanism that variably controls the A / R.

When step 545 is denied, the case of passing through step 515 and the case of step 52
It is considered that the route goes through 0. In the case of passing through step 520, it is possible that the vehicle is not in the accelerating state during the certain period B after the accelerating state that continued for the certain period A is completed.
On the other hand, in the case of passing through step 515, it is possible that the acceleration state is resumed during a certain period B after the acceleration state that continued for a certain period A ends. Here, the effect obtained in the former case is assumed, and by doing so, the turbo lag when re-acceleration is performed can be eliminated.

When step 545 is denied after passing through step 515, the situation just assumed as described above (acceleration again during a certain period B after the acceleration state which continued for a certain period A is completed) is completed. Immediately after the situation). Here, control of step 555 is performed, but even if step 545 is denied, step 51
In the case of passing through 5, the control may be such that normal electric motor control is performed (shift to normal electric motor control).

Next, another example of the supercharging pressure control when it is determined that the supercharging by the electric motor 11b is necessary after a predetermined time will be described. Here, when the required output to the engine 1 becomes a predetermined value or more under the condition that the opening of the throttle valve 13 is limited to a predetermined opening or less, it is determined that supercharging by the electric motor 11b is necessary after a predetermined time. . As a situation where the opening degree of the throttle valve 13 is limited to a predetermined opening degree or less, there may be a case where the electronically controlled throttle valve 13 fails and the opening degree cannot be adjusted (is not performed).

In the case of a failure, the electronically controlled throttle valve 13 of the present embodiment travels (referred to as retreat travel) with the control by the throttle motor 17 turned off for safety. Control of the electronically controlled throttle valve at the time of retreat traveling is described in Japanese Patent Laid-Open No. 10-153142. In this evacuation traveling, the throttle valve 13 is fixed to an opening degree such that the minimum intake air required for low speed traveling is obtained. Although the throttle valve 13 is fixed, it is possible to drive to the nearest service base. However, the intake air amount cannot be changed (or cannot be changed sufficiently) depending on the driving condition (for example, when climbing a hill or traveling on a highway).
Therefore, there is a concern that sufficient output cannot be obtained.

Therefore, in the control of the present embodiment, the required output to the engine 1 is equal to or more than the predetermined value in such a situation that the opening of the throttle valve 13 is limited to the predetermined opening or less during the evacuation traveling. In such a case, it is determined that supercharging by the electric motor 11b is necessary after a predetermined time. As a result, the electric motor 11b is driven and the required output is obtained. In addition, the opening of the throttle valve 13 that is fixed during the evacuation traveling is adjusted to the opening (relatively large opening) that is adjusted when traveling uphill or traveling on a highway.
If so, such an opening degree is not suitable for low-speed traveling, which is not preferable due to the nature of evacuation traveling. Therefore, the opening degree of the throttle valve 13 is set to a relatively small opening degree during the evacuation traveling.

A flow chart of the control described here is shown in FIG. First, it is determined whether or not the vehicle is in the evacuation travel (step 600). If the vehicle is not in the evacuation mode, the intake air amount control by the throttle valve 13 and the supercharging pressure control by the electric motor 11b are performed as usual (step 60).
5). If the vehicle is running in the evacuation mode, it is determined whether or not the output of the engine 1 is insufficient and an output assistance request is issued (step 610). Here, as an example in which such an output assistance request is issued, a case of a climbing situation will be described. Here, when the accelerator opening is equal to or more than a predetermined opening and the engine speed is less than or equal to a predetermined speed, or when the accelerator opening is at least a predetermined rotation and the vehicle speed is less than or equal to a predetermined value. Is determined to be an uphill condition, and an output assistance request is generated.

If there is no output assistance request, normal evacuation traveling control is performed (step 615). In normal evacuation traveling, the throttle valve 13 is fixed, so control is performed via the ignition timing or the fuel injection amount, or combustion is performed according to the operation amount of the accelerator pedal 14 detected by the accelerator positioning sensor 15 of the driver. Output control is performed by changing the number of cylinders to be performed. However, such control has a narrow control range, and there is a concern that sufficient output cannot be obtained in the above-described climbing situation. Therefore, step 61
In the case where 0 is affirmed, the electric motor 11b is driven to increase the intake air amount to improve the output (step 62).
0).

Here, the supercharging by the electric motor 11b is variably controlled according to the operation amount of the accelerator pedal 14 detected by the accelerator positioning sensor 15. At this time, the ignition timing control, the fuel injection amount control, the cylinder variable control, etc. described above may be used together. By doing so, the output during the evacuation traveling can be secured.

The present invention is not limited to the above embodiment. Further, the supercharging pressure control means does not have to be configured by a single component, but may be configured by a plurality of components (for example, ECU, 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.

[0055]

According to the supercharging pressure control device of the present invention, when the predicting means predicts that supercharging by the electric motor is necessary after a predetermined time, the supercharging by the electric motor is forcibly performed. As a result, good output characteristics and driving feeling can be realized.

[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 a first example of electric motor control.

FIG. 6 is a flowchart showing a second example of electric motor 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.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Osamu Igarashi             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. (72) Inventor Hironari Hashimoto             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. (72) Inventor Chika Kamiwa             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. F-term (reference) 3G005 EA04 EA15 EA16 EA20 GA00                       GA04 GD02 GE01 GE04 GE08                       GE09 HA02 HA06 HA15 JA02                       JA06 JA24 JA39 JA45 JB02                       JB20                 3G092 AA01 AA02 AA06 AA09 AA18                       BA02 DB04 DC03 EA09 EA11                       EA14 EA17 EC07 FA03 FA06                       HA06Z HA16X HA16Z HE01Z

Claims (4)

[Claims] 1. An electric motor capable of rotating a compressor of a turbocharger arranged in association with an internal combustion engine to change a supercharging pressure, and an electric motor control means for controlling the electric motor.
The electric motor control means comprises a situation determination means for determining whether or not the electric motor should be stopped, and a prediction means for predicting the necessity of supercharging by the electric motor after a predetermined time. When the predicting means predicts that supercharging by the electric motor is necessary after a predetermined time,
A supercharging pressure control device forcibly performing supercharging by the electric motor even when the condition judging means judges that the electric motor should be stopped. 2. An actual supercharging pressure detecting means for detecting an actual supercharging pressure and a target supercharging pressure calculating means for calculating a target supercharging pressure are further provided, wherein the electric motor control means is provided with the actual supercharging pressure. The electric motor is controlled based on the actual supercharging pressure detected by the pressure detecting means and the target supercharging pressure calculated by the target supercharging pressure calculating means, and the situation determining means detects the actual supercharging pressure detecting means by the actual supercharging pressure detecting means. The method according to claim 1, wherein when the determined actual supercharging pressure is higher than the target supercharging pressure calculated by the target supercharging pressure calculating means, it is determined that the electric motor should be stopped. Supercharging pressure control device. 3. The predicting means determines that a condition in which supercharging by the electric motor is required after a lapse of a predetermined time until a predetermined time elapses after the acceleration state ends. 2. The boost pressure control device according to 2. 4. The throttle valve for adjusting the intake air amount, and the intake air amount control means for controlling the throttle valve are further provided, wherein the situation determining means has an opening of the throttle valve equal to or less than a predetermined opening. When it is limited to, it is determined that the electric motor is to be stopped, the predicting means, while the opening of the throttle valve is limited to a predetermined opening or less, the required output of the internal combustion engine The supercharging pressure control device according to any one of claims 1 to 3, characterized in that, when is greater than or equal to a predetermined value, it is determined that supercharging by the electric motor is necessary after a predetermined time.