JP7312373B2 - engine controller - Google Patents

Description

TECHNICAL FIELD The present invention relates to an engine control device, and more particularly to an engine control device having a turbocharger with movable vanes and control means capable of executing torque down control for reducing fuel injection quantity based on a shift command signal.

Conventionally, in a manual transmission vehicle equipped with a turbocharger, it is known that when shifting gears, the flow rate of exhaust gas supplied to the turbine decreases when the driver depresses the accelerator pedal, causing the rotation speed of the turbine and compressor to decrease.
A variable geometry turbocharger (VGT) with a movable vane exists as one of the effective techniques for improving acceleration responsiveness degradation caused by the turbo lag.

The turbocharger control device of Patent Document 1 includes a variable vane that can adjust the flow rate of exhaust gas supplied to the turbine, detects a shift-up state of an automatic transmission, sets the opening of the variable vane to the closed side, increases the exhaust pressure of the exhaust system, while supercharging during the shift, reduces the engine speed, and sets the opening of the variable vane to the open side when the shift-up is completed.
As a result, at the start of shift-up, the amount of closing of the variable vanes is increased to increase the flow velocity of the exhaust gas and increase the rotational speed of the turbine, thereby ensuring the energy of the exhaust gas.
In addition, when the shift-up is completed, the amount of closing of the variable vanes is reduced, thereby suppressing an excessive increase in the rotational speed of the turbine and eliminating an increase in exhaust resistance.

JP-A-10-331650

The turbocharger control device of Patent Document 1 improves acceleration responsiveness due to turbo lag by increasing the flow velocity of the exhaust gas and increasing the rotation speed of the turbine during shifting.
However, with the technique disclosed in Patent Document 1, there is a possibility that sufficient acceleration responsiveness cannot be ensured when the occupant depresses the accelerator pedal again during gear shifting.

As shown in FIG. 8, in an automatic transmission vehicle equipped with a VGT, when the accelerator pedal is continuously depressed, the running speed of the vehicle continuously increases, and shift-up to a high gear (power-on upshift) is continuously performed based on a predetermined shift map.
For example, when the shift change line of the shift map is crossed at time t1, the shift control unit outputs the shift command signal from time t1 to time t7. At the same time as outputting the shift command signal, the shift control section calculates time t3 as the inertia phase start timing and time t5 as the inertia phase end timing. During the inertia phase (from time t3 to time t5), in order to synchronize the engine speed and the frictional engagement element speed, the shift control unit outputs a torque down request signal, and the engine reduces the fuel injection amount to match the torque down request signal to execute shift torque down.

On the other hand, during the inertia phase of the automatic transmission, during the inertia phase of the automatic transmission, the movable vanes in the turbine chamber are controlled to decrease their target opening, and then at time t6, the target opening returns to the predetermined reference opening.
Since the rotational speed of the turbine is interlocked with the amount of closing of the movable vanes, the actual boost pressure of the intake air supplied to the combustion chamber of the engine decreases with substantially the same tendency as the target opening of the movable vanes.
Although the movable vanes are controlled to the closing side from the first half of the inertia phase when the engine speed is high, the exhaust pressure does not rise sharply due to the delay in response to the closing operation.

As described above, during power-on upshifting, the actual supercharging pressure decreases in response to the torque-down request signal after the start of the shift torque down. Therefore, even if the driver depresses the accelerator pedal during the shift torque down or immediately after the shift torque down, the vehicle cannot physically accelerate until the actual boost pressure increases and reaches the target boost pressure.
That is, the technique of Patent Document 1 is not sufficient in terms of acceleration responsiveness in upshifting of the automatic transmission, and there is room for further improvement.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an engine control apparatus and the like capable of improving acceleration responsiveness during gear shifting.

An engine control apparatus according to claim 1, wherein the engine control apparatus comprises a turbocharger with movable vanes whose opening can be adjusted to change the passage area of exhaust gas supplied to the turbine, and control means capable of executing torque down control for reducing fuel injection amount based on a shift command signal of an automatic transmission capable of switching between a plurality of gear stages, wherein the control means has a first opening characteristic set such that when the energy of the exhaust gas is high, the opening of the movable vanes is greater than when the energy of the exhaust gas is low. and performs cooperative vane control for controlling the amount of closing of the movable vanes based on a second opening characteristic that is set so that the amount of closing of the movable vanes is larger than that of the first opening when the shift command signal is output.When the shift command signal is output, the control means generates a close request signal that starts at a point in time earlier than a predicted start timing of the inertia phase of the automatic transmission by an operation delay time of the movable vanes and ends at a time point earlier than the predicted end timing of the inertia phase of the automatic transmission by the operation delay time of the movable vanes, and performs the cooperative vane control while the close request signal is being output.It is characterized by

In this engine control device, the control means performs basic vane control for controlling the amount of closing of the movable vane based on the first opening characteristic set so that when the energy of the exhaust gas is large, the opening of the movable vane is larger than when the energy of the exhaust gas is small. Therefore, when the energy of the exhaust gas is small, the flow velocity of the exhaust gas is increased by increasing the amount of closing of the variable vane and the rotational speed of the turbine is increased, whereby the energy of the exhaust gas can be secured and the energy of the exhaust gas is small. Acceleration can be performed in response to the driver's depression of the accelerator pedal. Also, when the energy of the exhaust gas is large, the flow velocity of the exhaust gas is slowed down by reducing the closing amount of the variable vane, and the rotation speed of the turbine is lowered to lower the exhaust pressure, thereby improving fuel efficiency and output.
When the gear shift command signal is output, the control means performs cooperative vane control that controls the amount of closing of the movable vane based on the second opening characteristic set so that the amount of closing is greater than the first opening characteristic. Therefore, it is possible to suppress a decrease in the actual boost pressure during gear shifting, and shorten the time required for the actual boost pressure to return to the target boost pressure when the driver depresses the accelerator pedal during gear shifting.

Then, the increase in the exhaust gas energy due to the increase in the closing amount of the movable vanes can be started in consideration of the time constant delay related to the structural inertia of the movable vanes, and the decrease in the actual supercharging pressure can be suppressed to further improve the acceleration responsiveness.

The invention of claim 2 is characterized in that, in the invention of claim 1 , the control means reduces the closing amount of the movable vane as the engine torque increases while the closing request signal is being output.
According to this configuration, exhaust gas energy can be increased while suppressing an increase in exhaust pressure due to an increase in engine torque.

A third aspect of the invention is characterized in that, in the first aspect of the invention, the control means reduces the closing amount of the movable vane as the engine speed increases while the closing request signal is being output.
According to this configuration, exhaust gas energy can be increased while suppressing an increase in exhaust pressure due to an increase in engine speed.

The invention of claim 4 is the invention of any one of claims 1 to 3 , wherein the control means increases the closing amount of the movable vane when the engine torque starts to decrease while the closing request signal is being output.
According to this configuration, exhaust gas energy can be increased in synchronism with a decrease in engine torque.

The invention of claim 5 is the invention of any one of claims 1 to 3 , wherein the control means increases the closing amount of the movable vane when the engine speed starts to decrease while the closing request signal is being output.
According to this configuration, exhaust gas energy can be increased in synchronization with a decrease in engine speed.

The invention of claim 6 is the invention of any one of claims 1 to 5 , wherein the control means has first and second control maps that set the first and second opening characteristics, respectively, and controls the closing amount of the movable vane based on the first and second control maps.
According to this configuration, it is possible to simplify the configuration for controlling the amount of closing of the movable vanes during shifting and non-shifting.

According to the engine control device of the present invention, it is possible to improve the acceleration responsiveness during shifting in an automatic transmission vehicle equipped with a turbocharger with movable vanes.

1 is a schematic configuration diagram of an engine according to Embodiment 1; FIG. FIG. 2 is a vertical cross-sectional view of a turbine chamber of the turbocharger; 4 is a time chart showing how each element changes during shifting; It is a figure which shows a 1st opening characteristic map. It is a figure which shows a 2nd opening characteristic map. 4 is a flowchart showing a vane control processing procedure; FIG. 10 is a time chart showing changes in a closing request signal and a target opening degree according to a modification; FIG. 6 is a time chart showing how each element changes during gear shifting according to the prior art;

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated based on drawing. The following description of preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its applications or uses.

Embodiment 1 of the present invention will be described below with reference to FIGS. 1 to 6. FIG.
As shown in FIG. 1, the engine system S according to the first embodiment includes, for example, an engine 1 as a 6-cylinder diesel engine, an automatic transmission 20, a turbocharger 30, an ECU (Electronic Control Unit) 40 (control means) for controlling the engine system S, and various sensors 51 to 56 as main components.

First, the engine 1 will be explained.
As shown in FIG. 1, an engine 1 is provided with a fuel injection valve 3 for supplying fuel to a combustion chamber 2 for each cylinder. Each fuel injection valve 3 is connected to a common rail (not shown) through a distribution passage. The common rail stores fuel pressure-fed from a fuel pump (not shown). A rotation speed sensor 51 capable of detecting the rotation speed (rpm) of the engine 1 is provided in each cylinder. The engine 1 also includes intake and exhaust ports 1a and 1b communicating with the combustion chamber 2, an intake passage 4 connected to the intake port 1a, an exhaust passage 5 connected to the exhaust port 1b, an EGR passage 6 communicating the intake passage 4 and the exhaust passage 5, and the like.

An airflow sensor 52, a compressor 32 of a turbocharger 30, a throttle valve 7, an intercooler 8, a surge tank 9, and the like are arranged in the intake passage 4 in this order from the upstream side. The surge tank 9 is provided with an intake pressure sensor 53 .
The exhaust passage 5 is provided with a turbine 31 of the turbocharger 30 and a catalyst (not shown) arranged downstream of the turbine 31 . An exhaust pressure sensor 54 that detects the exhaust pressure is arranged upstream of the turbine 31 . An EGR valve 10 is arranged in the middle of the EGR passage 6 . The EGR valve 10 is operated to be partially opened or fully opened at least in a low rotation and low load region through a solenoid valve (not shown) capable of duty control.

Next, the automatic transmission 20 will be explained.
As shown in FIG. 1, the automatic transmission 20 is connected to the engine 1 via a starting device (not shown). The automatic transmission 20 has a forward traveling gear stage (for example, 1st to 6th gears in the D range) and a reverse traveling gear stage, thereby shifting the rotation speed of the crankshaft 11 to a desired rotation speed and transmitting it to the drive wheels (not shown). It should be noted that the number of forward traveling gear stages is not limited to the first to sixth gear stages as long as there are a plurality of them.

Next, the turbocharger 30 will be explained.
The turbocharger 30 is configured to be small in size so as to efficiently supercharge the intake air supplied to the combustion chamber 2 even when the exhaust gas energy is low (in the low rotation region or the low load region).
In addition, the turbocharger 30 is provided with a plurality of movable vanes 33 so as to surround the entire periphery of the turbine 31. The movable vanes 33 constitute a variable geometry turbocharger (VGT) capable of changing the flow path area of the exhaust gas toward the turbine 31.

As shown in FIG. 2, in a turbine chamber 34 formed in a turbine casing, a plurality of movable vanes 33 are arranged so as to surround a turbine 31 arranged substantially in the center. Each movable vane 33 is rotatably supported by a support shaft 35 passing through one side wall of the turbine chamber 34 . When each movable vane 33 rotates clockwise around the support shaft 35 and is inclined to approach each other, the opening degree (flow path area) formed between the movable vanes 33 is narrowed, and high supercharging efficiency can be obtained even when the exhaust gas flow rate is small. On the other hand, if the movable vanes 33 are rotated counterclockwise and tilted away from each other, the degree of opening is increased, so even when the exhaust gas flow rate is large, the exhaust resistance can be reduced and the supercharging efficiency can be increased.

The ring member 36 is drivingly connected to a rod 39 of an actuator 38 (see FIG. 1) via a link mechanism 37 , and each movable vane 33 is rotated via the ring member 36 by the operation of the actuator 38 . The link mechanism 37 is composed of a connecting pin 37a whose one end is rotatably connected to the ring member 36, a connecting plate member 37b whose one end is rotatably connected to the other end of the connecting pin 37a, a columnar member 37c which is connected to the other end of the connecting plate member 37b and penetrates the outer wall of the turbine casing, and a connecting plate member 37d whose one end is connected to the protruding end of the columnar member 37c which protrudes outside the turbine casing. The other end of the plate member 37d is rotatably connected to the rod 39 by a connecting pin (not shown).

Next, the ECU 40 will be explained.
The ECU 40 includes a central processing unit that executes various programs, memory (RAM, ROM), an input/output bus, and the like. As shown in FIG. 1, the ECU 40 has a fuel control section 41, a shift control section 42, a vane control section 43 and the like as main components.

First, the fuel control section 41 will be described.
The fuel control unit 41 reads the target torque of the engine through a target torque map (not shown) set in advance based on the opening (%) of the accelerator pedal (not shown) detected by the accelerator opening sensor 55 and the engine speed detected by the speed sensor 51, and reads the target fuel injection amount through a target fuel injection amount map (not shown) set in advance based on the target torque, the engine speed, and the actual fresh air amount detected by the air flow sensor 52. The fuel control unit 41 controls the fuel injection amount supplied to the combustion chamber 2 by adjusting the excitation time of the fuel injection valve 3 based on the set target fuel injection amount and the fuel pressure in the common rail.

During shifting, the fuel control unit 41 sets a fuel correction amount based on the torque down request signal (see FIG. 3) output from the shift control unit 42, and reduces the fuel correction amount from the target fuel injection amount.
Therefore, as shown in FIG. 3, the fuel control unit 41 sharply reduces the fuel injection amount at the inertia phase start timing (time t3) to start shift torque reduction, and finishes the shift torque reduction at the inertia phase end timing (time t5), thereby synchronizing the engine speed and the frictional engagement element speed.

Next, the shift control section 42 will be described.
The shift control unit 42 reads the gear stage to be switched to via a preset shift map (not shown) based on the traveling speed of the vehicle detected by the vehicle speed sensor 56 and the accelerator opening detected by the accelerator opening sensor 55 for each driving range selected by the driver's operation of the shift lever (not shown), and controls the ON/OFF of the shift solenoid valve (not shown). The shift control unit 42 switches the spool positions of the respective shift valves via the shift solenoid valves, and engages the respective frictional engagement elements so as to form a combination for each gear stage.

Further, the shift control unit 42 predicts and calculates the inertia phase simultaneously with the start of the shift.
The inertia phase is one of the phases that occur during shifting, and is a phase in which the transmission input rotation speed changes mainly due to changes in the inertia of the driving system. Therefore, normally, in the torque phase at the beginning of the shift, the engine speed changes according to the accelerator operation, and in the inertia phase at the end of the shift, the engine speed changes due to the shift.

As shown in FIG. 3, in the case of a power-on upshift in which the running state of the vehicle crosses the shift change line of the shift map, for example, the shift change line for switching from 5th speed to 6th speed while maintaining the accelerator depression state, the shift control unit 42 generates a shift command signal and a torque down request signal, and outputs the shift command signal and the torque down request signal to the fuel control unit 41, respectively.
The shift command signal is output at time t1 when the running state of the vehicle crosses the shift change line of the shift map, and output is stopped at time t7 when a predetermined time required for completion of operation of the peripheral elements has elapsed from actual shift end time t5, which is the inertia phase end timing. The torque down request signal is output at the actual shift start time t3, which is the inertia phase start timing, and is decreased from a predetermined time before the actual shift end time so that the output is stopped at the actual shift end time t5.

The shift control unit 42 generates a dedicated closing request signal for controlling the movable vanes 33 during shifting, and outputs this closing request signal to the vane control unit 43 . The output level of this closing request signal corresponds to the required torque calculated value corresponding to the torque down control by the movable vanes 33 .
As shown in FIG. 3, the start time t2 of the closing request signal output period is the time when the closing operation response delay of the movable vanes 33 is taken into consideration from the time t3 which is the inertia phase start timing, and the end time t4 of the closing request signal output period is the time when the opening operation response delay of the movable vanes 33 is taken into consideration from the time t5 which is the inertia phase end timing. In this embodiment, the term "at the time of shifting" includes at least the shift torque down period or the period in which the shift command signal including the period immediately after the shift torque down is output.

Next, the vane control section 43 will be described.
The vane control unit 43 sets the target boost pressure based on the operating state of the engine 1, sets the target opening (%) of each movable vane 33 so that the actual boost pressure converges to the target boost pressure, and adjusts each movable vane 33 so that it reaches the target opening. The vane control unit 43 controls the movable vanes 33 under the conditions of the first mode during periods other than the closing request signal output period, and controls the movable vanes 33 under the conditions of the second mode during the closing demand signal output period.

The vane control unit 43 has first and second opening characteristic maps M1 and M2 (first and second control maps) that define the opening of the movable vanes 33 according to the exhaust gas energy.
As shown in FIG. 4, the first opening characteristic map M1 is a map used in the first mode. This map defines the relationship between the engine speed and the opening of the movable vane 33 for each accelerator opening (eg, 100%, 50%, 25%) corresponding to a load greater than zero. These characteristics are set so that the opening increases as the accelerator opening increases, and the opening increases as the engine speed increases. The characteristic for each accelerator opening is that the opening increases at a predetermined rate of increase from the starting point to a predetermined number of revolutions, and increases at a rate lower than the predetermined rate of increase above the predetermined number of revolutions.

As shown in FIG. 5, the second opening characteristic map M2 is a map used in the second mode. This map defines the relationship between the engine speed and the opening of the movable vane 33 for each accelerator opening (eg, 100%, 50%, 25%) corresponding to a load greater than zero. The characteristic for each accelerator opening in the second opening characteristic map M2 is set to be closer to the closing side than the characteristic for each accelerator opening in the first opening characteristic map M1, that is, the closing amount is larger. Similar to the first opening characteristic map M1, these characteristics are set such that the opening increases as the accelerator opening increases, and the opening increases as the engine speed increases. The characteristic for each accelerator opening is that the opening increases at a predetermined rate of increase from the starting point to a predetermined number of revolutions, and increases at a rate lower than the predetermined rate of increase above the predetermined number of revolutions.

The vane control unit 43 is configured to be capable of executing feedforward (F/F) control using the first and second opening degree characteristic maps M1 and M2 and feedback (F/B) control comparing the target supercharging pressure and the actual supercharging pressure in order to suppress a temporary operation delay due to the structure of the movable vanes 33.
In F/F control, the accelerator opening corresponding to the load is obtained from the difference between the required torque calculated value represented by the closing request signal and the torque down request signal, and the opening θ1 of the movable vane 33 is calculated using this accelerator opening, the engine speed, and one of the first and second opening characteristic maps M1 and M2. Here, F/F control based on the first opening characteristic map M1 corresponds to basic vane control, and F/F control based on the second opening characteristic map M2 corresponds to cooperative vane control.

In the F/B control, the difference between the target boost pressure and the actual boost pressure and the F/B gain are used to calculate the correction opening θ2 of the movable vane 33 for converging the actual boost pressure to the target boost pressure (see FIG. 3). The F/B gain in the second mode is set to be larger (stronger) than the F/B gain in the first mode. This is because in the second mode, the closing amount of the movable vanes 33 is increased during a high load period in which the engine speed is high and fuel is supplied, so that the operational responsiveness of the movable vanes 33 is enhanced.

Further, the vane control unit 43 is configured to be able to execute exhaust pressure protection control (exhaust pressure vane control) for fail-safe of the exhaust system mechanism. In the exhaust pressure protection control, when the exhaust gas pressure (exhaust pressure) detected by the exhaust pressure sensor 54 is equal to or higher than the pressure determination threshold value (Pa), which is the exhaust pressure constraint condition, the corrective opening degree θ3 of the movable vane 33 for reducing the exhaust pressure on the upstream side of the turbine 31 is calculated.
As shown in FIG. 3, when the exhaust pressure rises to the determination threshold value or more between times t3 and t4, an opening degree θ3 that can reduce the closing amount of the movable vane 33 according to the pressure difference between the exhaust pressure and the determination threshold value is calculated. Basically, during the closing request signal output period (time t2 to t4), the target opening degree θ of the movable vane 33 is set to decrease at a predetermined decrease rate. However, when the exhaust pressure rises to the determination threshold value or more, the target opening degree θ of the movable vane 33 is corrected to the opening side by the opening degree θ3. After the closing request signal output period ends, the target opening degree θ increases sharply at time t4 because the coordinated vane control is switched to the basic vane control.

In the exhaust pressure protection control, in order to prevent hunting of the detected value of the exhaust pressure sensor 54, smoothing processing with low response is performed in the first mode. Specifically, in the first mode, the average value (moving average) of a plurality of exhaust pressure detection values for each detection cycle is compared with a predetermined determination threshold value. Moreover, the determination threshold for the second mode is set to a lower value than the determination threshold for the first mode. This is because the amount of closing of the movable vanes 33 is increased during the period in which the closing request signal is output, so that the effect of the exhaust pressure is increased.

As described above, the vane control unit 43 switches between the first and second modes according to the speed change state, and arbitrates the opening degree θ1 by F/F control with the opening degree θ2 by F/B control and the opening degree θ3 by exhaust pressure protection control for each mode, and calculates the final target opening degree θ of the movable vane 33. This target opening degree θ is output to the actuator 38 as a command signal.

Next, an example of the vane control processing procedure by the ECU 40 will be described with reference to the flowchart shown in FIG. In the figure, Si (i=1, 2, . . . ) indicates each step.

First, in S1, the ECU 40 reads various signals and various control maps input from the sensors 51 to 56, and proceeds to S2.
At S2, it is determined whether or not the occupant is depressing the accelerator pedal.
If the result of determination in S2 is that the occupant is depressing the accelerator pedal, the process proceeds to S3. If the result of determination in S2 is that the occupant has not stepped on the accelerator pedal, the process returns.

At S3, it is determined whether or not the automatic transmission 20 performs an upshift to a high speed gear.
As a result of the determination in S3, if an upshift is to be performed, a close request signal is generated and output (S4) because the upshift is to be performed while the accelerator is depressed.
As shown in FIG. 3, when a power-on upshift is executed, the shift control unit 42 outputs a close request signal that starts at a point (time t2) earlier than the inertia phase start timing (time t3) by the closing operation response delay time of the movable vanes 33 and ends at a point (time t4) earlier than the inertia phase end timing (time t5) by the opening operation response delay time of the movable vanes 33, based on the inertia phase of the automatic transmission 20.
If the result of determination in S3 is that the upshift to the high speed gear is not to be executed, the process returns.

Next, since it is the closing request signal output period, the second mode is set and the second opening characteristic map M2 is selected (S5). After the second mode is set, F/F control (S6), which is cooperative vane control, F/B control (S7), and exhaust pressure protection control (S8) are simultaneously processed in parallel.
After S6 to S8 are completed, the opening θ2 calculated in the F/B control process and the opening θ3 calculated in the exhaust pressure protection control process are adjusted with respect to the opening θ1 calculated in the F/F control process to calculate the target opening θ of the movable vane 33, and a command signal corresponding to this target opening θ is output to the actuator 38 (S9).

After S9, in S10, it is determined whether or not the closing request signal output period has ended.
If the closing request signal output period ends as a result of the determination in S10, the control mode is switched from the second mode to the first mode (S11), and the process returns. If the closing request signal output period continues (has not ended) as a result of the determination in S10, the process returns to S6 to S8 to calculate the next opening degrees θ1 to θ3.

Next, the operation and effects of the control device for the engine 1 will be described.
According to this control device for the engine 1, the ECU 40 performs basic vane control for controlling the amount of closing of the movable vanes 33 based on the first opening characteristic map M1, which is set so that the opening of the movable vanes 33 is larger when the energy of the exhaust gas is high than when the energy of the exhaust gas is small. Therefore, even when the energy of the exhaust gas is small, the vehicle can be accelerated in response to the driver's depression of the accelerator pedal. When the energy of the exhaust gas is large is when the engine speed is high, or when the engine load is high (when the accelerator opening is large, the amount of depression of the accelerator pedal is large), or the like.
Further, when the energy of the exhaust gas is large, the flow velocity of the exhaust gas is slowed down by reducing the closing amount of the movable vane 33, and the rotational speed of the turbine 31 is lowered to lower the exhaust pressure, thereby improving fuel efficiency and output. When the shift command signal is output, the ECU 40 performs cooperative vane control that controls the amount of closing of the movable vanes 33 based on the second opening characteristic map M2, which is set so that the closing amount is larger than that of the first opening characteristic map M1. Therefore, it is possible to suppress a decrease in the actual boost pressure during gear shifting, and shorten the time required for the actual boost pressure to return to the target boost pressure when the driver depresses the accelerator pedal during gear shifting.

The ECU 40 is characterized in that, when outputting the shift command signal, the close request signal is generated during the time t2, which is earlier than the predicted start timing t3 of the inertia phase of the automatic transmission 20 by the operation delay time of the movable vanes 33, and ends at the time t4, which is earlier than the predicted end time t5 of the inertia phase of the automatic transmission 20 by the operation delay time of the movable vanes 33, and cooperative vane control is performed while the close request signal is being output. As a result, an increase in exhaust gas energy due to an increase in the amount of closing of the movable vanes 33 can be started in consideration of the time constant delay associated with the structural inertia of the movable vanes 33, thereby suppressing a decrease in the actual supercharging pressure and further enhancing acceleration responsiveness.

Since the ECU 40 reduces the closing amount of the movable vane 33 as the engine torque (load) increases while the closing request signal is being output, exhaust gas energy can be increased while suppressing an increase in exhaust pressure accompanying an increase in engine torque.

Since the ECU 40 reduces the closing amount of the movable vane 33 as the engine speed increases while the closing request signal is being output, exhaust gas energy can be increased while suppressing an increase in exhaust pressure accompanying an increase in the engine speed.

The ECU 40 has first and second opening characteristic maps M1 and M2, respectively, and controls the amount of closing of the movable vanes 33 based on the first and second opening characteristic maps M1 and M2. Therefore, it is possible to simplify the configuration of the control of the amount of closing of the movable vanes 33 during shifting and non-shifting.

Next, a modified example in which the above embodiment is partially changed will be described.
1) In the above embodiment, an example of the automatic transmission 20 capable of shifting from 1st speed to 6th speed based on the shift map in the D range has been described.

2) In the above embodiment, the target opening degree θ of the movable vanes 33 is set to decrease at a predetermined rate during the closing request signal output period (t2 to t4).
As shown in FIG. 7, when the exhaust gas energy starts to decrease at time t3 during the closing request signal output period, the closing amount of the movable vane 33 may be increased, for example, the target opening θ may be set to a minimum value. In particular, when the ECU 40 increases the closing amount of the movable vanes 33 when the engine torque starts to decrease during the closing request signal output period, the exhaust gas energy can be increased in synchronization with the engine torque decrease. Further, when the ECU 40 increases the closing amount of the movable vane 33 when the engine speed starts to decrease during the closing request signal output period, the exhaust gas energy can be increased in synchronization with the decrease in the engine speed.

3) In the above-described embodiment, when the exhaust pressure rises above the judgment threshold value, the closing amount of the movable vanes 33 is set to the opening degree θ3 that decreases according to the pressure difference between the exhaust pressure and the judgment threshold value. As a result, the reliability of the exhaust system can be reliably ensured.

4) In addition, without departing from the scope of the present invention, those skilled in the art can implement various modifications to the above-described embodiment or combinations of the embodiments, and the present invention includes such modifications.

1 engine 20 automatic transmission 30 turbocharger 31 turbine 33 movable vane 40 ECU
M1 First opening characteristic map M2 Second opening characteristic map

Claims (6)

An engine control device comprising: a turbocharger with movable vanes whose opening can be adjusted to change the passage area of exhaust gas supplied to a turbine;
The control means performs basic vane control for controlling the amount of closing of the movable vane based on a first opening characteristic set so that the opening of the movable vane is larger when the energy of the exhaust gas is large than when the energy of the exhaust gas is small, and performs cooperative vane control of controlling the amount of closing of the movable vane based on a second opening characteristic set such that the amount of closing is larger than that of the first opening characteristic when the shift command signal is output.
The control device is characterized in that, when the gear shift command signal is output, the control means generates a closing request signal that starts at a point in time earlier than a predicted start timing of the inertia phase of the automatic transmission by an operation delay time of the movable vanes and ends at a time point earlier than the predicted end timing of the inertia phase of the automatic transmission by the operation delay time of the movable vanes, and performs the cooperative vane control while the close request signal is being output. 2. The engine control device according to claim 1, wherein said control means reduces the closing amount of said movable vane as the engine torque increases while said closing request signal is being output. 2. The engine control device according to claim 1, wherein said control means reduces the closing amount of said movable vane as the engine speed increases while said closing request signal is being output. The engine control device according to any one of claims 1 to 3, wherein the control means increases the closing amount of the movable vane when the engine torque starts to decrease while the closing request signal is being output. The engine control device according to any one of claims 1 to 3, wherein the control means increases the closing amount of the movable vane when the engine speed starts to decrease while the closing request signal is being output. The engine control device according to any one of claims 1 to 5, wherein the control means has first and second control maps that set the first and second opening characteristics, respectively, and controls the amount of closing of the movable vane based on the first and second control maps.

Images