JP2017180627A - Control device of engine with turbo supercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of an engine with a turbo supercharger capable of controlling an engine to execute smooth gear change without causing shift shock.SOLUTION: A control device of an engine (10) with a turbo supercharger has PCM (60) for determining driver request driving force requested by a driver on the basis of an operation state of a vehicle including an operation of an accelerator pedal, estimating an upper limit torque outputtable by the engine in a shift stage after gear change by an automatic transmission, on the basis of a present operation state of the engine, making the automatic transmission execute gear change when the driver request driving force is available by the upper limit torque after the gear change by the automatic transmission, and making the automatic transmission keep a present shift stage when the driver request driving force is not available due to the upper limit torque after the gear change by the automatic transmission.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a control device for an engine with a turbocharger, and more particularly, to a control device for an engine with a turbocharger that controls an engine having an automatic transmission and a turbocharger to output a target torque. About.

  2. Description of the Related Art Conventionally, in a control device that has an automatic multi-stage forward transmission and controls the output of an engine so that a target driving force set based on the vehicle speed and the accelerator opening is obtained, it has been prepared for each shift stage of the automatic transmission. One that calculates a target driving force from a map is known (see, for example, Patent Document 1).

JP 2008-164158 A

  By the way, in an internal combustion engine such as a gasoline engine or a diesel engine, a turbocharger is provided in order to improve the engine output, and the operation state of the vehicle (for example, various operations such as an accelerator pedal, a brake pedal, and a steering by a driver, a vehicle speed) The supercharging pressure by the turbocharger is controlled in accordance with the target torque determined based on the travel torque such as the air temperature, the atmospheric pressure, the road gradient, and the road surface μ. The turbocharger rotates the turbine with the exhaust gas of the engine, drives a compressor provided in the intake passage of the engine by this rotation, and supercharges the air supplied to each cylinder of the engine.

  When the engine control device as described in Patent Document 1 is applied to an engine with a turbocharger as described above, the supercharging pressure is caused by the rotational inertia of the turbine and compressor of the turbocharger. Due to the delay in the change of the actual output torque, the actual output torque may be excessive or insufficient with respect to the target torque, and the target driving force may not be obtained at the shift stage after the shift. In this case, a shock occurs before and after the shift.

  The present invention has been made to solve the above-described problems of the prior art, and is equipped with a turbocharger that can control an engine so that a smooth shift can be performed without causing a shift shock. An object of the present invention is to provide an engine control device.

In order to achieve the above object, an engine control apparatus according to the present invention is an engine control apparatus with a turbocharger that controls an engine having an automatic transmission and a turbocharger to output a target torque. The driver requested driving force determining means for determining the driver requested driving force requested by the driver based on the driving state of the vehicle including the operation of the accelerator pedal, and the shift by the automatic transmission based on the current operating state of the engine. Upper limit torque prediction means for predicting an upper limit torque that can be output by the engine at a later shift stage, and if the driver-requested driving force can be realized by the upper limit torque after shifting by the automatic transmission, causes the automatic transmission to perform a shift, If the driver's requested driving force cannot be achieved with the upper limit torque after shifting by the automatic transmission, the automatic transmission will retain the current gear position. And having a that shift control means.
In the present invention configured as described above, the upper limit torque predicting means predicts the upper limit torque that can be output by the engine at the shift stage after the shift by the automatic transmission based on the current operating state of the engine, and the shift control means. If the driver-requested driving force can be realized by the upper limit torque after the shift by the automatic transmission, the automatic transmission is caused to execute the shift, and if the driver-requested driving force cannot be realized by the upper limit torque after the shift, the current shift Since the speed is maintained, it is possible to prevent a shift shock from being caused by executing a gear shift even in a driving state where the driver requested driving force cannot be obtained at the gear position after the gear shift due to a rise in the boost pressure or the like. And the engine can be controlled so that a smooth speed change is performed.

In the present invention, it is preferable that the upper limit torque predicting unit predicts the upper limit torque based on the engine speed at the speed stage after the shift and the current supercharging pressure by the turbocharger.
In the present invention configured as described above, for example, even when the engine speed is low and sufficient supercharging pressure cannot be obtained, the upper limit torque that the engine can output after shifting is accurately predicted by reflecting the state. Thus, it is accurately determined whether or not the driver-requested driving force can be realized by the upper limit torque after the shift by the automatic transmission, and the engine is controlled so that a smooth shift can be performed without causing a shift shock. be able to.

  According to the control apparatus for an engine with a turbocharger according to the present invention, the engine can be controlled so that a smooth shift can be performed without causing a shift shock.

1 is a schematic configuration diagram of an engine system to which a control device for an engine with a turbocharger according to an embodiment of the present invention is applied. It is a block diagram which shows the electric constitution of the control apparatus of the engine with a turbocharger by embodiment of this invention. It is a flowchart of the engine control process by embodiment of this invention. It is a flowchart of the shift control process by embodiment of this invention. It is an example of the shift control map of the automatic transmission according to the embodiment of the present invention. It is an example of the time chart at the time of performing the shift control process by embodiment of this invention.

  Hereinafter, a control device for an engine with a turbocharger according to an embodiment of the present invention will be described with reference to the accompanying drawings.

<System configuration>
First, an engine system to which a control device for an engine with a turbocharger according to an embodiment of the present invention is applied will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic configuration diagram of an engine system to which a control device for an engine with a turbocharger according to an embodiment of the present invention is applied, and FIG. 2 is a control of the engine with a turbocharger according to an embodiment of the present invention. It is a block diagram which shows the electric constitution of an apparatus.

  As shown in FIGS. 1 and 2, the engine system 100 mainly includes an intake passage 1 through which intake air (air) introduced from the outside passes, intake air supplied from the intake passage 1, and fuel injection to be described later. An engine 10 (specifically, a gasoline engine) that generates fuel for the vehicle by burning an air-fuel mixture supplied from the valve 13 and an exhaust passage 25 that discharges exhaust gas generated by combustion in the engine 10. And sensors 40 to 54 for detecting various states relating to the engine system 100, and a PCM 60 (control device for an engine with a turbocharger) for controlling the entire engine system 100.

  In the intake passage 1, in order from the upstream side, the air cleaner 3 that purifies the intake air introduced from the outside, the compressor 4 a of the turbocharger 4 that boosts the intake air that passes through, and the outside air or cooling water cools the intake air. An intercooler 5, a throttle valve 6 that adjusts the amount of intake air (intake air amount) that passes through, and a surge tank 7 that temporarily stores intake air supplied to the engine 10 are provided.

  The intake passage 1 is provided with an air bypass passage 8 for returning a part of the intake air supercharged by the compressor 4a to the upstream side of the compressor 4a. Specifically, one end of the air bypass passage 8 is connected to the intake passage 1 downstream of the compressor 4a and upstream of the throttle valve 6, and the other end of the air bypass passage 8 is downstream of the air cleaner 3 and The intake passage 1 is connected to the upstream side of the compressor 4a.

  The air bypass passage 8 is provided with an air bypass valve 9 that adjusts the flow rate of intake air flowing through the air bypass passage 8 by an opening / closing operation. The air bypass valve 9 is a so-called on / off valve that can be switched between a closed state in which the air bypass passage 8 is completely closed and an open state in which the air bypass passage 8 is completely opened.

  The engine 10 mainly supplies an intake valve 12 for introducing the intake air supplied from the intake passage 1 into the combustion chamber 11, a fuel injection valve 13 for injecting fuel toward the combustion chamber 11, and a supply to the combustion chamber 11. Spark plug 14 for igniting the mixture of the intake air and fuel, a piston 15 reciprocating by combustion of the air-fuel mixture in the combustion chamber 11, a crankshaft 16 rotated by reciprocating motion of the piston 15, and combustion And an exhaust valve 17 that exhausts exhaust gas generated by combustion of the air-fuel mixture in the chamber 11 to the exhaust passage 25.

  Further, the engine 10 uses the variable intake valve mechanism 18 and the variable exhaust valve as the variable valve timing mechanism, with the operation timings of the intake valve 12 and the exhaust valve 17 (corresponding to the opening / closing timing of the valve) as the variable valve timing mechanism. The mechanism 19 is variably configured. As the variable intake valve mechanism 18 and the variable exhaust valve mechanism 19, various known types can be applied. For example, the operation of the intake valve 12 and the exhaust valve 17 is performed using a mechanism configured in an electromagnetic or hydraulic manner. Timing can be changed.

  The exhaust passage 25 is rotated by exhaust gas passing through in order from the upstream side, and the turbine 4b of the turbocharger 4 that drives the compressor 4a by this rotation, such as a NOx catalyst, a three-way catalyst, an oxidation catalyst, etc. Catalyst devices 35a and 35b having an exhaust gas purification function are provided. Hereinafter, when these catalyst devices 35a and 35b are used without being distinguished from each other, they are simply referred to as “catalyst device 35”.

  Further, an EGR device 26 is provided on the exhaust passage 25 to recirculate a part of the exhaust gas to the intake passage 1 as EGR gas. The EGR device 26 includes an EGR passage 27 having one end connected to the exhaust passage 25 upstream of the turbine 4b and the other end connected to the intake passage 1 downstream of the compressor 4a and downstream of the throttle valve 11; An EGR cooler 28 that cools the gas and an EGR valve 29 that controls the amount (flow rate) of EGR gas flowing through the EGR passage 27 are provided. The EGR device 26 corresponds to a so-called high pressure EGR device (HPL (High Pressure Loop) EGR device).

  The exhaust passage 25 is provided with a turbine bypass passage 30 that bypasses the exhaust gas without passing through the turbine 4b of the turbocharger 4. The turbine bypass passage 30 is provided with a waste gate valve (hereinafter referred to as “WG valve”) 31 for controlling the flow rate of the exhaust gas flowing through the turbine bypass passage 30.

  Further, in the exhaust passage 25, a passage between an upstream connection portion of the EGR passage 27 and an upstream connection portion of the turbine bypass passage 30 is branched into a first passage 25a and a second passage 25b. . The first passage 25a has a larger diameter than the second passage 25b. In other words, the second passage 25b has a smaller diameter than the first passage 25a, and an opening / closing valve 25c is provided in the first passage 25a. When the opening / closing valve 25c is open, the exhaust gas basically flows into the first passage 25a, and when the opening / closing valve 25c is closed, the exhaust gas flows only into the second passage 25b. Therefore, when the opening / closing valve 25c is closed, the flow rate of the exhaust gas becomes larger than when the opening / closing valve 25c is open. The on-off valve 25c is closed in the low rotation speed region, and the exhaust gas whose flow rate has been increased is supplied to the turbine 4b of the turbocharger 4, so that the turbocharger 4 can perform supercharging even in the low rotation region. ing.

The engine system 100 is provided with sensors 40 to 54 that detect various states relating to the engine system 100. Specifically, these sensors 40 to 54 are as follows. The accelerator opening sensor 40 detects an accelerator opening that is an accelerator pedal opening (corresponding to an amount by which the driver has depressed the accelerator pedal). The air flow sensor 41 detects an intake air amount corresponding to the flow rate of the intake air passing through the intake passage 1 between the air cleaner 3 and the compressor 4a. The temperature sensor 42 detects the temperature of intake air passing through the intake passage 1 between the air cleaner 3 and the compressor 4a. The pressure sensor 43 detects the supercharging pressure. The throttle opening sensor 44 detects the throttle opening that is the opening of the throttle valve 6. The pressure sensor 45 detects intake manifold pressure (pressure in the surge tank 7) corresponding to the pressure of intake air supplied to the engine 10. The crank angle sensor 46 detects the crank angle in the crankshaft 16. The intake side cam angle sensor 47 detects the cam angle of the intake camshaft. The exhaust side cam angle sensor 48 detects the cam angle of the exhaust camshaft. The temperature sensor 49 detects the temperature (water temperature) of the cooling water of the engine 10. The WG opening degree sensor 50 detects the opening degree of the WG valve 31. The O ₂ sensor 51 detects the oxygen concentration in the exhaust gas upstream of the catalyst device 35a, and the O ₂ sensor 52 detects the oxygen concentration in the exhaust gas between the catalyst device 35a and the catalyst device 35b. The vehicle speed sensor 53 detects the speed of the vehicle (vehicle speed). The knock sensor 54 is provided, for example, in a cylinder block of the engine 10 and detects vibration caused by knocking of the engine 10. These various sensors 40 to 54 output detection signals S140 to S154 corresponding to the detected parameters to the PCM 60, respectively.

  The PCM 60 also receives various information about the automatic transmission from the TCM 70 (Transmission Control Module) that controls the automatic transmission of the vehicle (for example, whether the current shift stage, the shift point at which the shift is performed has been reached, The engine speed at the time of shifting is input.

  The PCM 60 controls the components in the engine system 100 based on the detection signals S140 to S154 input from the various sensors 40 to 54 described above and various information related to the automatic transmission input from the TCM 70. Specifically, as shown in FIG. 2, the PCM 60 supplies a control signal S106 to the throttle valve 6, controls the opening / closing timing and throttle opening of the throttle valve 6, and sends a control signal S109 to the air bypass valve 9. To supply the control signal S131 to the WG valve 31, to control the opening of the WG valve 31, to supply the control signal S113 to the fuel injection valve 13, The injection amount and the fuel injection timing are controlled, the control signal S114 is supplied to the spark plug 14, the ignition timing is controlled, and the control signals S118 and S119 are supplied to the variable intake valve mechanism 18 and the variable exhaust valve mechanism 19, respectively. Then, the operation timing of the intake valve 12 and the exhaust valve 17 is controlled, and the control signal S129 is supplied to the EGR valve 29, so that the EGR valve Controlling the 9 opening.

  In particular, in the present embodiment, the PCM 60 predicts the upper limit torque that can be output by the engine 10 at the shift stage after the shift by the automatic transmission based on the current operating state of the engine 10, and shifts the driving force requested by the driver. If it is possible to achieve the upper limit torque at a later shift stage, the automatic transmission is caused to perform a shift by the TCM 70, and if the driver-requested driving force cannot be achieved, the automatic transmission is caused to hold the current shift stage, If the driver-requested driving force cannot be obtained after a shift, the current shift stage is maintained even when the shift point is reached, and the occurrence of a shift shock is prevented. The PCM 60 corresponds to the “control device for an engine with a turbocharger” in the present invention, and functions as “driver required driving force determining means”, “upper limit torque predicting means”, and “shift control means” in the present invention.

  Each component of the PCM 60 includes a CPU, various programs that are interpreted and executed on the CPU (including basic control programs such as an OS and application programs that are activated on the OS to realize specific functions), programs, and various types It is constituted by a computer having an internal memory such as a ROM or RAM for storing data.

<Engine control processing>
Next, basic control of the engine 10 performed in the embodiment of the present invention will be described with reference to FIG. FIG. 3 is a flowchart of the engine control process according to the embodiment of the present invention. This engine control process is activated and executed repeatedly when the ignition of the vehicle is turned on and the PCM 60 is powered on.

  When the engine control process is started, as shown in FIG. 3, in step S <b> 1, the PCM 60 acquires various types of information related to the driving state of the vehicle. Specifically, the PCM 60 detects the accelerator opening detected by the accelerator opening sensor 40, the intake air amount detected by the air flow sensor 41, the vehicle speed detected by the vehicle speed sensor 53, the presence or absence of knocking detected by the knock sensor 54, Acquires the gear stage currently set for the transmission.

  Next, in step S2, the PCM 60 sets a target acceleration based on the driving state of the vehicle acquired in step S1. Specifically, the PCM 60 determines the acceleration corresponding to the current vehicle speed and gear position from acceleration characteristic maps (created in advance and stored in a memory or the like) defined for various vehicle speeds and various gear speeds. A characteristic map is selected, and a target acceleration corresponding to the accelerator opening detected by the accelerator opening sensor 40 is determined with reference to the selected acceleration characteristic map.

  Next, in step S3, the PCM 60 determines a target torque of the engine 10 for realizing the target acceleration determined in step S2. In this case, the PCM 60 determines a target torque within the range of torque that can be output by the engine 10 based on the current vehicle speed, shift speed, road surface gradient, road surface μ, and the like.

In parallel with the processing in steps S2 to S3, in step S4, the PCM 60 determines whether knocking has been detected based on the detection signal acquired from the knock sensor 54 in step S1.
As a result, when knocking is detected, the process proceeds to step S5, and the PCM 60 increases the correction amount (ignition retard amount) when correcting the ignition timing to the retard side in order to suppress knocking. On the other hand, if knocking is not detected, the process proceeds to step S6, and the PCM 60 decreases the ignition retard amount. Thus, every time knocking is detected by the knock sensor 54, the ignition timing is gradually corrected to the retard side, and when knocking is not detected, the ignition timing is returned to the advance side. However, the ignition retard amount is set so as not to exceed the retard limit determined in advance by experiments from the viewpoint of combustion stability in consideration of significant deterioration in combustion efficiency and misfire.

  After step S3 and step S5 or S6, the process proceeds to step S7, where the PCM 60 performs ignition according to the operating state of the engine 10 including the current engine speed acquired in step S1 and the target torque determined in step S3. The reference ignition timing by the plug 14 is set. Specifically, the PCM 60 calculates a target indicated torque by adding a loss loss due to friction loss or pumping loss to the target torque, and defines the relationship between the ignition timing and the indicated torque for various charging efficiencies and various engine speeds. Range corresponding to the current engine speed and in which knocking does not occur (the knock limit ignition set in advance in each ignition advance map) from the ignition advance map (prepared and stored in a memory or the like). The ignition advance map is selected so that the target indicated torque can be obtained when the ignition timing is as close as possible to the MBT in the retarded angle range), and the target indicated torque is obtained by referring to the selected ignition advance map. The corresponding ignition timing is set as the reference ignition timing. Then, the PCM 60 corrects the set reference ignition timing to the retard side by the ignition retard amount set in step S5 or S6.

  Next, in step S8, the PCM 60 sets a target charging efficiency for causing the engine 10 to output the target torque determined in step S3. Specifically, the PCM 60 obtains a heat amount (required heat amount) necessary for outputting the target indicated torque, and obtains a target charging efficiency necessary for generating the required heat amount. When the reference ignition timing is retarded by the ignition retard amount set in step S5 or S6 in step S7, the PCM 60 increases the target charging efficiency in accordance with the ignition retard amount, and the target torque is appropriately adjusted from the engine 10. To be output.

  Next, in step S9, the PCM 60 opens the throttle valve 6 in consideration of the air amount detected by the air flow sensor 31 so that air corresponding to the target charging efficiency set in step S8 is introduced into the engine 10. And the opening / closing timing of the intake valve 12 via the variable intake valve mechanism 18 is determined.

  Next, in step S10, the PCM 60 controls the throttle valve 6 and the variable intake valve mechanism 18 based on the throttle opening determined in step S10 and the opening / closing timing of the intake valve 12, and also according to the operating state of the engine 10, etc. The fuel injection valve 13 is controlled based on the target equivalence ratio determined in this way and the actual air amount estimated based on the detection signal S141 of the airflow sensor 41 and the like.

  In parallel with the processing in steps S9 to S10, in step S11, the PCM 60 acquires the target supercharging pressure by the turbocharger 4. For example, a map indicating the relationship between the target torque and the target supercharging pressure for various engine speeds is stored in advance in a memory or the like, and the PCM 60 refers to the map to determine the current engine speed and the step S3. A target boost pressure corresponding to the determined target torque is acquired.

  Next, in step S12, the PCM 60 determines the opening degree of the WG valve 31 for realizing the target boost pressure acquired in step S11.

  Next, in step S13, the PCM 60 controls the actuator of the WG valve 31 based on the opening set in step S12. In this case, the PCM 10 controls the actuator of the WG valve 31 according to the opening set in step S12, and brings the boost pressure detected by the pressure sensor 43 closer to the target boost pressure acquired in step S11. The actuator is feedback controlled.

In parallel with the processing in steps S9 to S10 and steps S11 to S13, in step S14, the PCM 60 controls the spark plug 14 so that ignition is performed at the ignition timing set in step S7.
After steps S10, S13, and S14, the PCM 60 ends the engine control process.

<Transmission control process>
Next, with reference to FIG. 4, the shift control process of the automatic transmission performed in the embodiment of the present invention will be described. FIG. 4 is a flowchart of the shift control process according to the embodiment of the present invention. This shift control process is repeatedly executed by the PCM 60 at a predetermined cycle, and is executed in parallel with the engine control process shown in FIG.

  When the shift control process is started, first, in step S21, the PCM 60, based on detection signals input from the accelerator opening sensor 40, the crank angle sensor 46, the pressure sensor 43, and the like, Get the number and supercharging pressure.

  Next, in step S22, the PCM 60 determines that the engine speed immediately after the shift when the automatic transmission shifts the shift stage from the current shift stage to the next shift stage at the current vehicle speed (hereinafter referred to as “next shift stage if necessary”). The engine speed is called from the TCM 70. The next gear stage engine speed is obtained based on the current vehicle speed and the speed reduction ratio of the next gear stage.

Next, in step S23, the PCM 60 determines whether the engine 10 has a predetermined speed at the next gear stage engine speed based on the accelerator opening degree and the boost pressure obtained in step S21 and the next gear stage engine speed obtained in step S22. The predicted torque that can be output ahead of the predicted time is calculated. The predicted time is a time until the output torque of the engine 10 responds when the throttle valve 6 and the variable intake valve mechanism 18 are controlled based on the target torque, and is 200 ms, for example.
For example, the PCM 60 acquires the target torque determined in step S3 of the engine control process illustrated in FIG. Then, refer to a map corresponding to the current engine speed from among supercharging pressure maps (preliminarily created and stored in a memory or the like) showing the relationship between the supercharging pressure and the output torque for various engine speeds. Then, the boost pressure corresponding to the target torque is calculated as the target boost pressure. Further, a value between the current supercharging pressure and the target supercharging pressure (for example, a value obtained by internally dividing the current supercharging pressure and the target supercharging pressure into 1: 9) is set to 200 ms ahead. Calculated as the predicted boost pressure, and the output torque corresponding to the predicted boost pressure in the boost pressure map corresponding to the next gear stage engine speed is calculated as the predicted torque that can be output 200 ms ahead at the next speed engine speed. To do.

Next, in step S24, the PCM 60 determines whether or not the driving state of the vehicle has reached a shift point at which a shift by the automatic transmission is executed based on the information input from the TCM 70.
FIG. 5 is an example of a shift control map that is referred to when the TCM 70 controls the automatic transmission. In this shift control map, the horizontal axis represents the vehicle speed, and the vertical axis represents the accelerator opening. The TCM 70 refers to the shift control map illustrated in FIG. 5 and sets the shift speed corresponding to the current vehicle speed and accelerator opening as the target shift speed. Then, the TCM 70 outputs a signal indicating that the driving state of the vehicle has reached the shift point to the PCM 60 when the target shift stage changes due to a change in the vehicle speed or the accelerator opening.

In step S24, if the driving state of the vehicle has reached the shift point, the process proceeds to step S25, and the PCM 60 can realize the driving force requested by the driver after the shift by the automatic transmission based on the predicted torque calculated in step S23. Determine whether.
Specifically, the PCM 60 drives the driving force required by the driver who operates the accelerator pedal (driver-requested driving) for the driving force necessary to realize the target acceleration determined in step S2 of the engine control process illustrated in FIG. Power). Further, based on the predicted torque calculated in step S23 and the speed reduction ratio of the next gear, a predicted driving force that can be output after the shift is calculated. If the calculated predicted driving force is greater than or equal to the driver required driving force, it is determined that the driver required driving force can be realized after the shift, and if the predicted driving force is less than the driver required driving force, the driver required driving force is realized after the shift. Can't judge.

As a result, when the driver-requested driving force can be realized after the shift with the predicted torque calculated in step S23, the process proceeds to step S26, and the PCM 60 outputs a signal to the TCM 70 to instruct the start of the shift control.
On the other hand, if the driving state of the vehicle has not reached the shift point in step S24, or if the driver requested driving force cannot be realized after the shift by the predicted torque in step S25, the process proceeds to step S27, and the PCM 60 performs the shift control. A signal indicating that the current gear position is to be maintained without performing the operation is output to the TCM 70.
After step S26 or S27, the PCM 60 ends the shift control process.

<Engine operation>
Next, with reference to FIG. 6, the operation of the engine when the shift control process according to the embodiment of the present invention is executed will be described. FIG. 6 is an example of a time chart when the shift control process according to the embodiment of the present invention is executed. Specifically, FIG. 6 shows, in order from the top, the accelerator opening, the engine speed, the current boost pressure, the output torque, the shift speed, the next shift speed, the engine speed, and the predicted torque at the next shift speed. .

  As shown in FIG. 6, when the accelerator opening starts to increase at time t0, the engine 10 is controlled to increase the output torque accordingly, and the engine speed gradually increases. Further, the next gear stage engine speed (in FIG. 6, the engine speed immediately after the shift when the automatic transmission shifts the gear stage from the first speed to the second speed at the current vehicle speed) is also the current gear stage (the first speed in FIG. 6). ) In the same manner as the engine speed at

  When the driving state of the vehicle reaches the shift point at time t1, the PCM 60 obtains the next gear stage engine speed Nea at the vehicle speed at time t1 from the TCM 70, and sets the accelerator opening APO and the boost pressure Pn at time t1. Based on this, a predicted torque Tqa that can be output 200 ms ahead at the next gear stage engine speed Nea is calculated. Then, based on the predicted torque Tqa and the reduction ratio of the next gear (second speed), a predicted driving force that can be output after the shift is calculated, and it is determined whether or not the predicted driving force is equal to or greater than the driver requested driving force.

  If the predicted driving force is equal to or greater than the driver request driving force, the PCM 60 outputs a signal to the TCM 70 to instruct the start of the shift control. The TCM 70 starts the shift control of the automatic transmission, and the gear position is switched to the next gear position (second gear) at time t2. In this case, since the driving force that can be output by the engine 10 immediately after the shift is equal to or greater than the driver-requested driving force, a shift shock does not occur due to insufficient driving force.

  On the other hand, when the predicted driving force is less than the driver required driving force, the PCM 60 outputs a signal to the TCM 70 instructing to maintain the current gear position without performing the shift control. Therefore, the TCM 70 does not perform the shift control of the automatic transmission, and the shift speed is maintained at the current shift speed (first speed) even at time t2. That is, when the driver-requested driving force cannot be obtained at the shift stage after the shift due to the increase in the boost pressure or the like, the shift is not performed, so that it is possible to prevent a shift shock from occurring due to the insufficient driving force.

<Effect>
Next, the effect of the control apparatus for the turbocharged engine according to the above-described embodiment of the present invention will be described.

  First, the PCM 60 predicts the upper limit torque that can be output by the engine 10 at the shift stage after the shift by the automatic transmission based on the current operating state of the engine 10, and determines it based on the operating state of the vehicle including the operation of the accelerator pedal. If the driver requested driving force can be realized by the upper limit torque after the shift by the automatic transmission, the automatic transmission is caused to execute the shift, and if the driver requested driving force cannot be realized by the upper limit torque after the shift, the automatic transmission To maintain the current gear position, causing a gear shift shock by executing a gear shift even though the driver requested driving force cannot be obtained at the gear position after the gear shift due to a delay in the boost pressure rise. Therefore, the engine can be controlled so that smooth shifting is performed.

  Further, since the PCM 60 predicts the upper limit torque based on the engine speed at the speed stage after the shift and the current supercharging pressure by the turbocharger 4, for example, a sufficient supercharging pressure is obtained with a low engine speed. Even if it is not possible, it is possible to accurately predict the upper limit torque that can be output by the engine 10 reflecting the state, and whether or not the driver requested driving force can be realized by the upper limit torque after shifting by the automatic transmission. Can be accurately determined, and the engine can be controlled so that a smooth shift can be performed without causing a shift shock.

1 intake passage 4 turbocharger 4a compressor 4b turbine 6 throttle valve 10 engine 13 fuel injection valve 14 spark plug 18 variable intake valve mechanism 25 exhaust passage 31 WG valve 40 accelerator opening sensor 43 pressure sensor 53 vehicle speed sensor 60 PCM
70 TCM
100 engine system

Claims (2)

A control device for an engine with a turbocharger that controls an engine having an automatic transmission and a turbocharger so as to output a target torque,
Driver requested driving force determining means for determining a driver requested driving force requested by the driver based on a driving state of the vehicle including an operation of an accelerator pedal;
Upper limit torque predicting means for predicting an upper limit torque that can be output by the engine at a shift stage after the shift by the automatic transmission based on the current operating state of the engine;
When the driver-requested driving force can be realized by the upper limit torque after shifting by the automatic transmission, the automatic transmission is caused to perform a shift, and the driver-requested driving force is changed by the upper limit torque after the shifting by the automatic transmission. If not feasible, a control device for an engine with a turbocharger comprising shift control means for causing the automatic transmission to maintain a current gear position.   2. The turbocharged engine according to claim 1, wherein the upper limit torque predicting unit predicts the upper limit torque based on an engine speed at a gear stage after a shift and a current supercharging pressure by the turbocharger. Control device.

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