JP2009299505A - Device and method for controlling turbocharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the power performance of a vehicle while suppressing an excessive increase of supercharging pressure by appropriately setting an allowed region of transitional control that accelerates the startup of supercharging pressure than normally. <P>SOLUTION: An ECU controls a variable nozzle type turbocharger installed in a vehicle equipped with an engine and a transmission. When a value obtained by subtracting actual supercharging pressure Pin from target supercharging pressure Ptrg exceeds a threshold (YES at S104), the ECU calculates a transitional control allowed upper limit value NE(N) corresponding to a shift gear stage formed of an automatic transmission (S108). When an engine speed NE is higher than an idling speed and lower than the transitional control allowed upper limit value NE(N) (YES at S110), the ECU executes the transitional control of a nozzle vane (S114). The transitional control allowed upper limit values NE(N) are set according to startup characteristics of the supercharging pressure of respective shift gear stages. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to control of a variable nozzle type turbocharger including a variable nozzle that increases or decreases the effective area of a flow path formed inside an exhaust turbine, and more particularly to control of the opening degree of a nozzle vane.

  There are two types of internal combustion engines for automobiles: naturally aspirated engines and supercharged engines. As the supercharging mechanism, an exhaust turbine drive type generally called a turbocharger and a mechanical drive type generally called a supercharger have been put into practical use. A turbocharger rotates a turbine with the energy of exhaust gas, compresses intake air with a compressor directly connected thereto, and supplies the compressed air to an engine.

  In an engine with a turbocharger, when the engine is in a low speed rotation range, the rise of the supercharging pressure is delayed because the flow rate of the exhaust gas is small, and supercharging by the turbocharger becomes insufficient. As a countermeasure, a turbocharger that increases the kinetic energy given to the turbine rotor by reducing the opening, that is, the area of the turbine nozzle, has been developed.

  The variable nozzle type turbocharger is a kind of such a turbocharger, and is provided with a plurality of rotatable nozzle vanes (hereinafter also referred to as “variable nozzles” and “variable nozzles”), and a turbine formed between the nozzle vanes. The opening degree of the turbine nozzle when the exhaust gas of the engine is guided from the nozzle to the turbine rotor can be changed.

  However, even when the opening of the variable nozzle is reduced and the boost pressure rises earlier when the engine is in the low speed range, it is formed with the engine load at this time and the gear stage connected to the engine. Depending on the transmission gear speed, the exhaust pressure may exceed the intake pressure, the engine output may decrease, and the acceleration performance may deteriorate. A technique for solving such a problem is disclosed in, for example, Japanese Patent Laid-Open No. 63-29026 (Patent Document 1).

  A control device disclosed in Japanese Patent Application Laid-Open No. 63-29026 includes an opening / closing part that opens and closes an exhaust bypass passage that bypasses the exhaust turbine, an exhaust inlet nozzle area variable part that changes an area of the exhaust inlet nozzle of the exhaust turbine, A variable displacement exhaust turbocharger comprising: a supercharging pressure detection unit that detects a supercharging pressure; and a supercharging pressure control unit that controls an opening / closing unit and an exhaust inlet nozzle area variable unit according to the detected supercharging pressure. The supercharging pressure of the internal combustion engine is controlled. The control device includes a gear position detecting unit that detects a gear position of a transmission connected to the internal combustion engine, and an opening / closing unit or an exhaust inlet in preference to the supercharging pressure control unit according to the detected gear position of the transmission. A gear position control unit that controls the nozzle area variable unit.

According to the control device disclosed in Japanese Patent Application Laid-Open No. 63-29026, when the exhaust pressure rises rapidly when the exhaust pressure rises rapidly by narrowing the exhaust nozzle area, the internal combustion due to the supercharging effect occurs. Considering that the engine output improvement effect cannot be obtained, the exhaust inlet nozzle area and the bypass exhaust amount are controlled according to the gear position that indirectly indicates the tendency of the exhaust pressure increase. Therefore, a decrease in engine output due to an increase in exhaust pressure can be prevented, a good boost pressure rise can be obtained, and the acceleration performance of the internal combustion engine can be improved.
JP-A-63-29026 Japanese Utility Model Publication No. 62-29445

  By the way, conventionally, an upper limit value of the engine speed (hereinafter also referred to as “permitted upper limit value”) that permits execution of transient control that makes the rise of the boost pressure faster than usual is uniformly set for all shift speeds. Was. However, the rising characteristic of the supercharging pressure by the above-described variable nozzle turbocharger differs depending on the gear stage formed by the transmission. Therefore, in order to suppress the excessive increase of the supercharging pressure at all gears (to guarantee the reliability of the turbo), it is adjusted to the gear with the lowest engine speed when the supercharging pressure starts to increase rapidly. It is necessary to set the allowable upper limit. However, when the allowable upper limit value is set in this way, in the case where another gear stage is formed, the execution of the transient control is unnecessarily limited, and the rising of the boost pressure is not optimal, and the vehicle power The performance cannot be improved accurately.

  However, Japanese Patent Laid-Open No. 63-29026 makes no mention of the relationship between the upper limit of permission and the gear position. The same applies to Japanese Utility Model Publication No. 62-29445.

  The present invention has been made in order to solve the above-described problems, and its purpose is to appropriately set an allowable region for transient control that accelerates the rise of the boost pressure more than usual, and to overcharge the boost pressure. It is an object to provide a turbocharger control device and control method capable of improving the power performance of a vehicle while suppressing an increase.

  A control device according to a first invention controls a turbocharger mounted on a vehicle including an engine and a transmission having a plurality of shift stages. The turbocharger includes a nozzle whose opening is adjusted by an actuator, a turbine driven by engine exhaust guided by the nozzle, and a compressor driven by the turbine to compress intake air of the engine. The control device is formed of a transmission among storage means for storing a plurality of permission upper limit values set so as to respectively correspond to a plurality of shift speeds, and a plurality of permission upper limit values stored in the storage means. A selection means for selecting a permitted upper limit value corresponding to the gear position being determined, and a determination for determining whether or not the engine speed is included in a permitted area having the permitted upper limit value selected by the selecting means as an upper limit. And when the intake boost pressure is changed, the change speed of the intake boost pressure is greater when the determination means determines that the engine speed is included in the permitted range than when it is not determined. And a control means for controlling an actuator for adjusting the opening of the nozzle.

  In the control device according to the second aspect of the invention, in addition to the configuration of the first aspect, the plurality of permitted upper limit values are set according to the rising characteristics of the supercharging pressure by the turbocharger at each corresponding shift stage. .

  In the control device according to the third aspect of the invention, in addition to the configuration of the second aspect of the invention, the control apparatus corresponds to the first shift stage having the first characteristic that the supercharging pressure starts to increase rapidly at the first engine speed. The first allowable upper limit value is a second gear corresponding to a second gear having a second characteristic in which the supercharging pressure starts to increase rapidly at a second engine speed lower than the first engine speed. Is set to a value larger than the allowable upper limit value.

  In the control device according to the fourth invention, in addition to the configuration of any one of the first to third inventions, the permission area is higher than a predetermined idle rotation speed and higher than a selected permission upper limit value. It is a low area.

  In the control device according to the fifth invention, in addition to the configuration of any one of the first to fourth inventions, when the control means increases the supercharging pressure, the engine speed is higher than the permitted upper limit value selected. Is higher, the nozzle opening is adjusted to the first opening, and when the engine speed is lower than the selected permitted upper limit, the second opening is smaller by a predetermined amount than the first opening. adjust.

  The control device according to a sixth aspect of the invention further includes a calculation means for calculating a target boost pressure of intake air based on the state of the engine in addition to the configuration of any one of the first to fourth aspects of the invention. When changing the actual boost pressure of the intake air to the target boost pressure calculated by the calculation means, the control means is more effective when the engine speed is lower than the selected allowable upper limit than when it is higher. The opening degree of the nozzle is adjusted so that the supply pressure is rapidly changed to the target supercharging pressure.

  The control methods according to the seventh to twelfth inventions have the same requirements as the control devices according to the first to sixth inventions.

  According to the present invention, when the rotation speed of the internal combustion engine is included in the permitted region, the control (transient control) is performed to adjust the opening of the nozzle so that the change rate of the supercharging pressure is increased. The upper limit value of the permission area is set to a permission upper limit value corresponding to a gear stage formed by the transmission among a plurality of permission upper limit values set to correspond to the plurality of gear speeds, respectively. In this way, the transient control permission region can be optimally set for each gear position. Therefore, the power performance of the vehicle can be improved while suppressing an excessive increase in the supercharging pressure.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  FIG. 1 schematically shows a vehicle equipped with a variable nozzle turbocharger control device according to the present embodiment.

  The engine body 500 is an internal combustion engine that burns a mixture of fuel and air injected from an injector (not shown) in a combustion chamber of a cylinder. The piston in the cylinder is pushed down by the combustion, and the crankshaft is rotated.

  Air necessary for combustion in the engine body 500 is filtered by the air cleaner 100, compressed by the compressor 320 of the turbocharger 300, cooled by the intercooler 120, and guided to the intake manifold 140. The intake air flow rate GA is adjusted by the intake throttle valve 130.

  Intake manifold 140 distributes intake air to each cylinder of engine body 500. The exhaust gas generated in each cylinder is collected by the exhaust manifold 160, then passed through the turbine 340 of the turbocharger 300, and finally purified by the catalytic converter 700 and discharged. In order to prevent an excessive supercharging effect by the turbocharger 300, an exhaust bypass passage 800 and a waste gate valve (WGV) 900 are provided so that the exhaust gas can bypass the turbine 340.

  In the turbine 340 of the turbocharger 300, a turbine rotor (also called a turbine wheel, a turbine blade, or the like) 350 is rotated by exhaust gas. Since the compressor blade 330 of the compressor 320 is connected to the turbine rotor 350 by the rotating shaft 310, the compressor blade 330 rotates with the turbine rotor 350 to compress the intake air, that is, has a supercharging action. As will be described in detail later, the turbine 340 is provided with a plurality of rotatable nozzle vanes 360 so that the opening, that is, the area of the turbine nozzle formed between the nozzle vanes 360 can be changed. Yes. Therefore, the turbine nozzle is called a variable nozzle. The opening degree of the variable nozzle is adjusted by an actuator (DC servo motor) 370.

  Automatic transmission 600 is connected to engine body 500 via torque converter 610. The automatic transmission 600 forms a forward travel gear stage (for example, 1st to 6th gear stage) and a reverse travel gear stage, thereby shifting the rotational speed of the crankshaft to a desired rotational speed and driving wheels (see FIG. (Not shown). In addition, as long as there are a plurality of forward travel gear stages, it is not limited to the 1st to 6th gear stages.

  The ECU (Electronic Control Unit) 8000 includes an air flow meter 110, a pressure sensor 220, an intake pipe temperature sensor 230, an oxygen sensor 240, a water temperature sensor 510, an engine speed sensor 520, a vehicle speed sensor 8002, a position switch 8006, and an accelerator opening sensor. Each signal from 8010 and stroke sensor 8014 is input.

  The air flow meter 110 detects the intake air amount GA. The pressure sensor 220 detects an actual supercharging pressure (actual pressure in the intake pipe) Pin. The intake pipe temperature sensor 230 detects the intake pipe temperature T. The oxygen sensor 240 detects the excess air ratio λ. Water temperature sensor 510 detects engine coolant temperature TE. The engine speed sensor 520 detects the engine speed NE. The vehicle speed sensor 8002 detects the vehicle speed VS. The position switch 8006 detects the position (shift position) SP of the shift lever operated by the driver. The accelerator opening sensor 8010 detects an accelerator pedal opening (accelerator opening) ACC. The stroke sensor 8014 detects the stroke amount BS of the brake pedal. These sensors output a detection result to ECU 8000.

  ECU 8000 controls actuator 370 so as to adjust the opening of the variable nozzle based on the detection results from these sensors. Further, the ECU 8000 controls the injector of the engine body 500 to adjust the fuel injection amount Qfin, or controls the intake throttle valve 130 to adjust the intake air amount GA.

  Further, ECU 8000 automatically controls the shift gear stage formed by automatic transmission 600 in correspondence with shift position SP. ECU 8000, when shift position SP is located at the D (drive) position, based on a shift line determined from vehicle speed VS and accelerator opening degree ACC, shift gear of any one of first to sixth gears. The automatic transmission 600 is controlled so that a stage is formed. ECU 8000 controls automatic transmission 600 in a neutral state (a state in which no power is transmitted) when shift position SP is in the N (neutral) position.

  FIG. 2 shows a cross-sectional view of a turbocharger 300 that is a variable nozzle turbocharger. FIGS. 3A and 3B show a state in which the nozzle vane 360 in the turbocharger 300 is opened. FIGS. 4A and 4B show a state in which the nozzle vane 360 in the turbocharger 300 is closed.

  With reference to these drawings, nozzle opening control of the turbocharger 300 will be described. A nozzle vane 360 provided on the turbine 340 side is an object of nozzle opening degree control. A plurality of (13 in this embodiment) rotatable nozzle vanes 360 are provided in the gas passage at the turbine inlet for introducing the exhaust gas to the turbine rotor 350. The opening degree of the variable nozzle formed between the nozzle vanes 360 is adjusted by rotating the drive arm 382 via the link 390. The lift amount of the link 390 is controlled by the actuator 370. Connected to the rod 392.

  The driving force from the actuator 370 controlled by the ECU 8000 is transmitted in the order of the rod 392, the link 390, the unison ring 380, and the driving arm 382. The rod 392 expands and contracts by the action of the actuator 370. The unison ring 380 is rotated by the driving force transmitted from the rod 392. When the driving arm 382 rotates around the point X (see FIG. 3) by the rotation of the unison ring 380, the nozzle vane 360 disposed on the back side of the driving arm 382 similarly rotates around the point X. Thereby, the flow velocity and pressure of the exhaust gas input to the turbine 340 can be adjusted.

  For example, in the engine low and medium speed rotation region, the nozzle passage is throttled (the nozzle opening is reduced) and the exhaust gas flow rate is increased to increase the supercharging pressure, thereby reducing black smoke and improving torque. . On the other hand, in the engine high-speed rotation range, the nozzle passage is opened (the nozzle opening is increased) to lower the exhaust pressure, thereby improving fuel consumption and output and preventing the turbine 340 from over-rotating.

  As shown in FIG. 2, ECU 8000 outputs an opening degree command signal corresponding to a target opening degree of nozzle vane 360 (hereinafter also simply referred to as “target opening degree”) V to actuator driver 372. The actuator driver 372 sets a target lift amount (target position) of the rod 392 according to the target opening degree V, and the actuator 370 so that the actual lift amount of the rod 392 input from the actuator 370 becomes the target lift amount. The drive current is supplied to the motor.

  FIG. 5 shows the relationship between the target opening degree V of the nozzle vane 360 and the lift amount of the rod 392. As shown in FIG. 5, the lift amount of the rod 392 decreases the target opening V in the region where the target opening V is larger than the predetermined value V (1) (the region on the left side of V (1) in FIG. 5). The value is different between when the nozzle vane 360 is closed (when the nozzle vane 360 is closed) and when the target opening degree V is increased (when the nozzle vane 360 is opened).

  Further, a region where the target opening V is smaller than the predetermined value V (1) (region on the right side of V (1) in FIG. 5), that is, the fully closed opening Vmin when the nozzle vane 360 is fully closed is set to the predetermined value V ( In the region up to 1), the lift amount is maintained at the maximum value. In this region, the actual boost pressure Pin does not change. In the following description, the difference between the predetermined value V (1) and the fully closed opening degree Vmin is also referred to as “VN hiss amount”.

  FIG. 6 shows a functional block diagram of ECU 8000 which is a control device according to the present embodiment. ECU 8000 includes an input interface 8100, a calculation processing unit 8200, a storage unit 8300, and an output interface 8400.

  The input interface 8100 includes an actual boost pressure Pin from the pressure sensor 220, an engine speed NE from the engine speed sensor 520, a vehicle speed VS from the vehicle speed sensor 8002, a shift position SP from the position switch 8006, and an accelerator opening sensor 8010. Accelerator opening degree ACC from is received and transmitted to arithmetic processing unit 8200.

  Various information, programs, threshold values, maps, and the like are stored in the storage unit 8300, and data is read from or stored in the arithmetic processing unit 8200 as necessary.

  The storage unit 8300 stores a transient control permission upper limit value map. In this transient control permission upper limit value map, the control (hereinafter, also referred to as “transient control”) in which the target opening V of the nozzle vane 360 is rapidly reduced rapidly to make the actual boost pressure Pin rise earlier than usual. The upper limit value of the permitted engine rotation range (hereinafter also referred to as “transient control permission rotation range”) is stored for each transmission gear stage. That is, in the present embodiment, the transient control permission upper limit value NE (1) corresponding to the first speed gear stage, the transient control permission upper limit value NE (2) corresponding to the second speed gear stage, and the third speed gear stage are supported. Transient control permission upper limit value NE (3) Transient control permission upper limit value NE (4) corresponding to 4th gear stage Transient control permission upper limit value NE (5) corresponding to 5th gear stage, corresponding to 6th gear stage The transient control permission upper limit value NE (6) to be stored is stored.

  This transient control permission upper limit value NE (N) (NE (1) to NE (6)) is a boost characteristic of the boost pressure at each corresponding gear stage (engine speed when the boost pressure starts to increase rapidly). ). Specifically, the transient control permission upper limit value corresponding to the shift gear stage having a high engine speed at which the boost pressure starts to increase rapidly is the transient control corresponding to the shift gear stage having a low engine speed at which the boost pressure starts to increase rapidly. It is set to a value larger than the permitted upper limit value.

  The reason for setting the transient control permission upper limit NE (N) in this way is that the engine speed range in which the transient control described later is permitted is changed in consideration of the fact that the rising characteristic of the boost pressure differs for each transmission gear stage. This is to optimally set for each gear stage.

  Arithmetic processing unit 8200 includes target boost pressure calculation unit 8210, transient state determination unit 8220, transient control permission determination unit 8230, transient control unit 8240, and normal control unit 8250.

  Target boost pressure calculation unit 8210 calculates target boost pressure Ptrg based on the state of engine body 500 (for example, engine speed NE, actual boost pressure Pin, fuel injection amount Qfin, etc.).

  The transient state determination unit 8220 determines whether or not the above-described transient control is necessary. The transient state determination unit 8220 determines whether or not a value obtained by subtracting the actual boost pressure Pin from the target boost pressure Ptrg exceeds a threshold value, and if the threshold value is exceeded, transient control is necessary. Judged to be in a state.

  The transient control permission determination unit 8230 determines whether or not the above-described transient control permission condition is satisfied. The transient control permission determination unit 8230 determines whether or not the automatic transmission 600 is not in the neutral state and whether or not the engine speed NE is included in the above-described transient control permission rotation range, and the automatic transmission 600 is in the neutral state. Otherwise, when the engine speed NE is included in the transient control permission rotation range, it is determined that the transient control permission condition is satisfied.

  The transient control permission determination unit 8230 refers to the transient control permission upper limit value map stored in the storage unit 8300, and the transient control permission upper limit value NE (N) corresponding to the shift gear stage formed by the automatic transmission 600. And the selected transient control permission upper limit value NE (N) is set to the upper limit value of the transient control permission rotation range. The lower limit value of the transient control permission rotation range is set to the idle rotation speed. That is, the transient control permission rotation region is a region that is higher than the idle rotation speed and lower than the transient control permission upper limit value NE (N).

  The transient control unit 8240 executes the transient control of the nozzle vane 360 when the transient control permission determination unit 8230 determines that the engine speed NE is included in the upper transient control permission rotation range. Specifically, the transient control unit 8240 sets the target opening V to a value obtained by subtracting a predetermined amount from the normal target opening VR (transient target opening VT), and an opening command corresponding to the transient target opening VT. A signal is output to the actuator driver 372. The normal target opening VR is the target opening V of the nozzle vane 360 when normal control is performed (when transient control is not performed).

  The normal control unit 8250 executes normal control of the nozzle vane 360 when the transient control permission determination unit 8230 does not determine that the engine speed NE is included in the upper transient control permission rotation range. Specifically, the target opening V is set to the normal target opening VR, and an opening command signal corresponding to the normal target opening VR is output to the actuator driver 372.

  In the present embodiment, target boost pressure calculation unit 8210, transient state determination unit 8220, transient control permission determination unit 8230, transient control unit 8240, and normal control unit 8250 are all arithmetic processing units 8200. Although the description will be made assuming that the CPU functions as software, which is realized by executing a program stored in the storage unit 8300, it may be realized by hardware. Such a program is recorded on a storage medium and mounted on the vehicle.

  With reference to FIG. 7, a control structure of a program executed by ECU 8000 which is the control device according to the present embodiment will be described. Note that this program is repeatedly executed at a predetermined cycle time.

  In step (hereinafter, step is abbreviated as S) 100, ECU 8000 determines the target boost pressure based on the state of engine body 500 (for example, engine speed NE, actual boost pressure Pin, fuel injection amount Qfin, etc.). Ptrg is calculated.

  In S102, ECU 8000 calculates normal target opening VR based on target boost pressure Ptrg.

  In S104, ECU 8000 determines whether or not a value obtained by subtracting actual supercharging pressure Pin from target supercharging pressure Ptrg exceeds a threshold value. The case where the value obtained by subtracting the actual supercharging pressure Pin from the target supercharging pressure Ptrg exceeds the threshold is, as described above, when the target opening degree V needs to be rapidly reduced transiently. It is. If the value obtained by subtracting actual boost pressure Pin from target boost pressure Ptrg exceeds the threshold value (YES in S104), the process proceeds to S106. Otherwise (NO in S104), the process proceeds to S116.

  In S106, ECU 8000 determines whether automatic transmission 600 is not in the neutral state. If automatic transmission 600 is not in the neutral state (YES in S106), the process proceeds to S108. If automatic transmission 600 is in the neutral state (NO in S106), the process proceeds to S116.

  In S108, ECU 8000 calculates transient control permission upper limit NE (N) corresponding to the transmission gear stage formed by automatic transmission 600. As described above, ECU 8000 refers to the transient control permission upper limit value map stored in storage unit 8300, and calculates transient control permission upper limit value NE (N) corresponding to the transmission gear stage.

  In S110, ECU 8000 determines whether engine speed NE is included in the above-described transient control permission rotation range (that is, engine speed NE is higher than idle rotation speed or higher than transient control permission upper limit value NE (N)). Whether it is low or not. If engine speed NE is included in the transient control permission rotation range (YES in S110), the process proceeds to S112. Otherwise (NO in S110), the process proceeds to S116.

  In S112, ECU 8000 calculates transient target opening VT. ECU 8000 calculates a value obtained by subtracting a predetermined amount from normal target opening VR as transient target opening VT. The predetermined amount is set, for example, to the above-described VN hiss amount (see FIG. 5).

  In S114, ECU 8000 executes transient control of nozzle vane 360. The ECU 8000 sets the target opening V of the nozzle vane 360 to the transient target opening VT, and outputs an opening command signal corresponding to the transient target opening VT to the actuator driver 372.

  In S116, ECU 8000 executes normal control of nozzle vane 360. The ECU 8000 sets the target opening V of the nozzle vane 360 to the normal target opening VR, and outputs an opening command signal corresponding to the normal target opening VR to the actuator driver 372.

  A change in actual supercharging pressure Pin controlled by ECU 8000 serving as the control apparatus according to the present embodiment based on the above-described structure and flowchart will be described with reference to FIG.

  As shown in FIG. 8, the target boost pressure Ptrg starts to increase rapidly at time t1 when the vehicle is traveling in the N-speed gear stage, and at time t2, the actual boost pressure Pin is changed from the target boost pressure Ptrg. Assume that the reduced value exceeds the threshold value (YES in S104).

  In this case, since automatic transmission 600 is not in the neutral state (YES in S106), transient control permission upper limit value NE (N) corresponding to the Nth gear stage is calculated with reference to the transient control permission upper limit value map. (S108).

  As shown in FIG. 8, engine speed NE at time t2 is included in the transient control permission rotation range (region higher than idle rotation speed and lower than transient control permission upper limit NE (N)) (YES in S110). ), The execution of the transient control of the nozzle vane 360 is started (S112, S114). Thereby, the target opening degree V of the nozzle vane 360 is rapidly reduced, and the rise of the actual supercharging pressure Pin is made earlier than in the normal control (see the two-dot chain line in FIG. 8).

  Here, conventionally, the upper limit value of the transient control permission rotation range is the permission upper limit value corresponding to the gear position having the lowest engine speed when the supercharging pressure starts to increase rapidly regardless of the gear position (FIG. 8). NEmin). For this reason, even if the N-speed gear stage is a shift stage in which the boost pressure does not increase excessively even if the upper limit value of the transient control permission rotational range is increased above NEmin, the engine speed NE reaches NEmin at time t3. Transient control was unnecessarily limited. Therefore, as shown by the one-dot chain line in FIG. 8, the follow-up performance of the actual boost pressure Pin with respect to the target boost pressure Ptrg is not improved after time t3.

  On the other hand, in the present embodiment, the upper limit value of the transient control permission rotation range is set for each transmission gear stage. That is, during traveling at the N-speed gear stage, the upper limit value of the transient control permission rotation range is set to the transient control permission upper limit value NE (N) corresponding to the N-speed gear stage. As a result, the transient control time is lengthened without unnecessarily restricting the transient control at time t3, so that the followability of the actual boost pressure Pin with respect to the target boost pressure Ptrg can be improved after time t3. . Thereby, the time when the actual boost pressure Pin reaches the target boost pressure Ptrg can be shortened from the conventional time t5 to the time t4 without excessively increasing the actual boost pressure Pin. Therefore, the power performance of the vehicle can be improved while ensuring the reliability of the turbo.

  As described above, according to the control device according to the present embodiment, when the engine speed is included in the transient control permission region, the transient control that makes the rise of the actual boost pressure Pin faster than usual is executed. The upper limit value of the transient control permission area is set for each transmission gear stage formed by the transmission. Accordingly, in consideration of the fact that the rising characteristic of the supercharging pressure differs for each gear position, the permission region for transient control can be set optimally for each gear position. Therefore, it is possible to improve the power performance of the vehicle as compared with the case where the upper limit value of the transient control permission region is uniformly set while suppressing the excessive increase in the supercharging pressure.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic block diagram of a vehicle provided with the control apparatus of a variable nozzle type turbocharger. It is sectional drawing of a variable nozzle type turbocharger. It is FIG. (1) for demonstrating the function of a variable nozzle type turbocharger. It is FIG. (2) for demonstrating the function of a variable nozzle type turbocharger. It is a figure which shows the relationship between the target opening degree V of a nozzle vane, and the lift amount of a rod. It is a functional block diagram of the control apparatus of a variable nozzle type turbocharger. It is a flowchart which shows the control structure of ECU which is a control apparatus of a variable nozzle type turbocharger. It is a timing chart of the actual supercharging pressure Pin controlled by the control device of the variable nozzle turbocharger.

Explanation of symbols

  100 air cleaner, 110 air flow meter, 120 intercooler, 130 intake throttle valve, 140 intake manifold, 150 passage, 160 exhaust manifold, 220 intake pipe pressure sensor, 230 intake pipe temperature sensor, 240 oxygen sensor, 300 turbocharger, 310 rotating shaft, 320 compressor, 330 compressor blade, 340 turbine, 350 turbine rotor, 360 nozzle vane, 370 actuator (DC servo motor), 372 actuator driver, 380 unison ring, 382 drive arm, 390 link, 392 rod, 500 engine body, 510 temperature sensor 520 Engine speed sensor, 600 Automatic transmission, 610 Torque converter, 700 Catalytic converter, 800 Exhaust bypass passage, 900 waste gate valve (WGV), 8000 ECU, 8002 vehicle speed sensor, 8006 position switch, 8010 accelerator opening sensor, 8014 stroke sensor, 8100 input interface, 8200 arithmetic processing unit, 8210 target boost pressure calculation unit, 8220 Transient state determination unit, 8230 Transient control permission determination unit, 8240 Transient control unit, 8250 Normal control unit, 8300 Storage unit, 8400 Output interface.

Claims (12)

A turbocharger control device mounted on a vehicle including an engine and a transmission having a plurality of shift stages, wherein the turbocharger includes a nozzle whose opening is adjusted by an actuator, and the nozzle guided by the nozzle A turbine driven by engine exhaust; and a compressor driven by the turbine to compress intake air of the engine;
The controller is
Storage means for storing a plurality of permitted upper limit values set to respectively correspond to the plurality of shift speeds;
Selecting means for selecting a permission upper limit value corresponding to a shift speed formed by the transmission among the plurality of permission upper limit values stored in the storage means;
Determination means for determining whether or not the engine speed is included in a permission region having an upper limit of the permission upper limit value selected by the selection means;
When changing the supercharging pressure of the intake air, the rate of change of the supercharging pressure of the intake air is greater than when the engine speed is determined not to be determined by the determining means. And a control unit for controlling the actuator for adjusting the opening degree of the nozzle.   2. The turbocharger control device according to claim 1, wherein the plurality of permissible upper limit values are set according to rising characteristics of the supercharging pressure by the turbocharger at each corresponding shift stage.   The first allowable upper limit value corresponding to the first shift stage having the first characteristic in which the supercharging pressure starts to increase rapidly at the first engine speed is lower than the first engine speed. The set value is larger than a second allowable upper limit value corresponding to a second shift stage having a second characteristic in which the supercharging pressure starts to increase rapidly at an engine speed of 2. Turbocharger control device.   The turbocharger control device according to any one of claims 1 to 3, wherein the permission area is an area that is higher than a predetermined idle rotation speed and lower than the selected permission upper limit value.   The control means, when increasing the supercharging pressure, adjusts the opening of the nozzle to a first opening when the rotational speed of the engine is higher than the selected allowable upper limit value, The turbocharger control according to any one of claims 1 to 4, wherein when the rotational speed is lower than the selected allowable upper limit value, the second opening is adjusted to be a predetermined amount smaller than the first opening. apparatus. The control device further includes a calculation unit for calculating a target boost pressure of the intake air based on the state of the engine,
When the control means changes the actual boost pressure of the intake air to the target boost pressure calculated by the calculation means, when the engine speed is lower than the selected permitted upper limit value, 5. The turbocharger control device according to claim 1, wherein an opening degree of the nozzle is adjusted so that the actual supercharging pressure is rapidly changed to the target supercharging pressure. A control method performed by a control device for controlling a turbocharger mounted on a vehicle including an engine and a transmission having a plurality of shift stages, wherein the turbocharger includes a nozzle whose opening is adjusted by an actuator; A turbine driven by the exhaust of the engine guided by the nozzle, and a compressor driven by the turbine to compress the intake air of the engine;
The control method is:
Storing a plurality of permitted upper limit values set to respectively correspond to the plurality of shift speeds;
A selection step of selecting a permission upper limit value corresponding to a shift speed formed by the transmission among the plurality of permission upper limit values stored in the storage step;
A determination step of determining whether or not the engine speed is included in a permission region whose upper limit is the permission upper limit value selected in the selection step;
When changing the supercharging pressure of the intake air, the rate of change of the supercharging pressure of the intake air is greater than when the engine speed is determined to be included in the permission region in the determination step, compared to when it is not determined. And a control step of controlling the actuator that adjusts the opening of the nozzle.   The turbocharger control method according to claim 7, wherein the plurality of permitted upper limit values are set according to rising characteristics of the supercharging pressure by the turbocharger at each corresponding shift speed.   The first allowable upper limit value corresponding to the first shift stage having the first characteristic in which the supercharging pressure starts to increase rapidly at the first engine speed is lower than the first engine speed. 9. The value according to claim 8, wherein the boost pressure is set to a value larger than a second permitted upper limit value corresponding to a second shift stage having a second characteristic that starts to increase rapidly at an engine speed of 2. Turbocharger control method.   The turbocharger control method according to any one of claims 7 to 9, wherein the permission area is an area that is higher than a predetermined idle rotation speed and lower than the selected permission upper limit value.   In the control step, when increasing the supercharging pressure, when the engine speed is higher than the selected allowable upper limit value, the opening of the nozzle is adjusted to a first opening, The turbocharger control according to any one of claims 7 to 10, wherein when the rotational speed is lower than the selected upper limit value, the second opening is adjusted to be a predetermined amount smaller than the first opening. Method. The control method further includes a calculation step of calculating a target boost pressure of the intake air based on the state of the engine,
In the control step, when the actual boost pressure of the intake air is changed to the target boost pressure calculated in the calculation step, when the engine speed is lower than the selected allowable upper limit value, The turbocharger control method according to any one of claims 7 to 10, wherein an opening degree of the nozzle is adjusted so that the actual supercharging pressure is rapidly changed to the target supercharging pressure.

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