JP2007278252A - Turbocharger control unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turbocharger control unit capable of improving warm-up efficiency of a catalytic converter disposed downstream of a turbine installed in an engine exhaust system. <P>SOLUTION: When the catalytic converter 5 needs warming up, the turbocharger ECU 20 drives the turbine 2A of a turbocharger 2 for rotation at a target rotation speed. A pressure difference between exhaust gas inflow pressure and exhaust gas outflow pressure on a turbine 2A side therefore decreases into a predetermined range close to zero as much as possible in a short time, and consumption of exhaust gas heat energy by turbine 2A is inhibited. On this occasion, a group of variable vanes 2E of the turbocharger 2 is operated into a full open state so that a flow rate of exhaust gas passing the turbine 2A decreases and the exhaust heat energy acting on the turbine 2A is reduced. Exhaust gas having sufficient temperature is therefore quickly supplied to the catalytic converter 5, the catalytic converter 5 is efficiently warmed up in a short time and its warm-up efficiency is improved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a turbocharger control device, and more particularly, to a turbocharger control device in which a turbine capable of controlling the rotational speed is disposed upstream of a catalytic converter in an engine exhaust system.

  In an engine including a turbocharger that supercharges intake air to an engine and a catalytic converter that purifies engine exhaust, the turbine of the turbocharger is generally arranged upstream of the catalytic converter of the engine exhaust system. As this type of turbocharger, a turbocharger having an electric motor capable of controlling the rotational speed by directly rotating the compressor together with the turbine is generally known (see, for example, Patent Documents 1 and 2).

  By the way, the catalyst built in the catalytic converter normally increases its temperature gradually by the heat energy of the exhaust gas passing through the catalytic converter, and exhibits an exhaust purification function when it reaches a predetermined activation temperature. On the other hand, the turbocharger operates when the turbine is rotationally driven by exhaust heat energy.

  Therefore, if the turbocharger is in a normal operating state between the time when the catalyst reaches a predetermined activation temperature and the warm-up of the catalytic converter is completed, the turbine is supplied to the catalyst of the catalytic converter as much as the exhaust heat energy is consumed. The exhaust heat energy is reduced, the warm-up efficiency of the catalytic converter is lowered, and the warm-up time is lengthened.

In Patent Document 2, when the electric motor incorporated in the turbocharger is rotated by a turbine and used as a generator, the temperature of the exhaust purification device (catalytic converter) is lower than the appropriate range. A technology is disclosed in which the power generation amount is suppressed and the temperature of the exhaust purification device (catalytic converter) is maintained in an appropriate range.
JP 2004-340122 A JP 2004-143997 A

  By the way, the technique disclosed in Patent Document 2 suppresses the amount of power generated by a generator (electric motor) in order to maintain the temperature of an exhaust purification device (catalytic converter) within an appropriate range. It is not expected to shorten the warm-up time by increasing the warm-up efficiency when the converter is warmed up.

  Therefore, an object of the present invention is to provide a turbocharger control device capable of improving the warm-up efficiency of a catalytic converter disposed downstream of a turbine installed in an engine exhaust system.

  A turbocharger control device according to the present invention is a turbocharger control device in which a turbine capable of controlling the rotational speed is arranged upstream of a catalytic converter of an engine exhaust system, and determines when the catalytic converter needs to be warmed up. Further, when the catalytic converter needs to be warmed up, control means is provided for controlling the rotational speed of the turbine to reduce the pressure difference between the exhaust inlet pressure and the exhaust outlet pressure on the turbine side within a predetermined range.

  In the turbocharger control device according to the present invention, when the catalytic converter needs to be warmed up, the control means reduces the pressure difference between the exhaust gas inlet pressure and the exhaust gas outlet pressure on the turbine side of the turbocharger within a predetermined range. The resistance of the turbine is reduced, the exhaust heat energy for rotating the turbine is reduced, and the consumption of the exhaust heat energy by the turbine is suppressed. As a result, when the catalytic converter needs to be warmed up, exhaust gas having a sufficient temperature is supplied to the catalytic converter, so that the catalytic converter is efficiently warmed up in a short time and the warming up efficiency is improved.

  In the turbocharger control device of the present invention, the turbocharger preferably has an electric motor capable of rotating the turbine, and the control means is preferably configured to control the rotational speed of the turbine by controlling the electric motor. In this case, the rotation speed of the turbine can be quickly and accurately controlled by the electric motor, and exhaust gas having a sufficient temperature can be quickly supplied to the catalytic converter to efficiently warm up the catalytic converter in a short time. It becomes possible.

  The turbocharger preferably has a variable vane on the turbine side, and the control means is preferably configured to control the variable vane in the opening direction when the catalytic converter needs to be warmed up. In this case, when the catalytic converter needs to be warmed up, the flow rate of the exhaust gas passing through the turbine of the turbocharger is reduced, and the exhaust heat energy acting on the turbine is reduced. For this reason, it is possible to efficiently warm up the catalytic converter in a shorter time by supplying exhaust gas having a sufficient temperature to the catalytic converter.

  Here, the control means for controlling the variable vane in the opening direction when the catalytic converter needs to be warmed up may be configured to control the variable vane to the fully open state. In this case, when the catalytic converter needs to be warmed up, the variable vane is controlled to be fully open, the flow rate of the exhaust gas passing through the turbine of the turbocharger is greatly reduced, and the exhaust heat energy acting on the turbine is greatly reduced. For this reason, it becomes possible to warm up the catalytic converter more efficiently in a shorter time.

  Further, the control means may be configured to detect the actual temperature of the catalytic converter and to control the variable vane in the opening direction as the temperature difference between the actual temperature and the target temperature of the catalytic converter increases. In this case, when the catalytic converter needs to be warmed up, the lower the actually measured temperature of the catalytic converter, the more the variable vane is controlled in the opening direction, and the exhaust heat energy acting on the turbine is greatly reduced. Exhaust heat energy increases. For this reason, a catalytic converter having a low measured temperature can be efficiently warmed up in a short time.

  Further, the control means controls the supercharging pressure by the turbocharger compressor by controlling the opening degree of a bypass control valve installed in a bypass pipe that communicates the downstream side and the upstream side of the turbocharger compressor. It is preferable to be configured to control the pressure. In this case, an excessive increase in the supercharging pressure by the compressor is suppressed, the amount of compressed air supplied to the engine is reduced, and accordingly, the amount of exhaust discharged from the engine to the exhaust pipe is also reduced. Since the exhaust temperature rises, the catalytic converter can be efficiently warmed up in a shorter time.

  Here, in the turbocharger control device of the present invention, the control means determines when the in-vehicle battery needs to be charged and when the emission amount exceeds the reference value, and when the emission amount exceeds the reference value, It can be configured to stop the charging control of the in-vehicle battery corresponding to the need for charging. In this case, when the emission amount increases beyond the reference value, the on-board battery charging control by the alternator or the like is stopped, so that the engine load is reduced, the fuel consumption is suppressed, and further deterioration of the emission is suppressed. .

  In addition, the control means determines when the on-board battery needs to be charged and when the catalyst regeneration condition of the catalytic converter is met. When the catalyst regeneration condition of the catalytic converter is met, the control control of the on-vehicle battery corresponding to when the on-board battery needs to be charged is stopped. Can be configured to. In this case, when the catalyst regeneration condition of the catalytic converter is met, the on-board battery charging control by the alternator or the like is stopped, so that the engine load is reduced and the fuel consumption is suppressed.

  Further, the control means detects the actual temperature of the catalytic converter and the remaining amount of the on-vehicle battery, and sets the drive power of the motor to be larger as the temperature difference between the actual temperature and the target temperature of the catalytic converter is larger. It can be configured that the drive power of the electric motor is set to be smaller as the amount is smaller. In this case, when the catalytic converter needs to be warmed up, the drive power of the motor is set to be larger as the measured temperature of the catalytic converter is lower. Therefore, the rotational speed of the turbine is quickly and surely controlled by the electric motor so that the necessary exhaust heat energy is obtained. The catalytic converter can be quickly supplied to the catalytic converter, and the catalytic converter having a low measured temperature can be efficiently warmed up in a short time. Moreover, since the drive power of the electric motor is set to be smaller as the remaining amount of the in-vehicle battery is smaller, the decrease in the remaining amount of the in-vehicle battery is suppressed.

  In the turbocharger control device according to the present invention, when the catalytic converter needs to be warmed up, the control means reduces the pressure difference between the exhaust gas inlet pressure and the exhaust gas outlet pressure on the turbine side of the turbocharger within a predetermined range. The resistance of the turbine is reduced, the exhaust heat energy for rotating the turbine is reduced, and the consumption of the exhaust heat energy by the turbine is suppressed. Therefore, according to the present invention, exhaust having a sufficient temperature can be supplied to the catalytic converter when the catalytic converter needs to be warmed up, and the catalytic converter is efficiently warmed up in a short time to improve the warming up efficiency. Can be made.

  In the turbocharger control device of the present invention, when the turbocharger has an electric motor capable of rotationally driving the turbine, and the control means is configured to control the rotational speed of the turbine by controlling the electric motor, the rotational speed of the turbine is set. It becomes possible to control quickly and accurately by the electric motor, and it is possible to quickly supply exhaust gas having a sufficient temperature to the catalytic converter and efficiently warm up the catalytic converter in a short time.

  Further, in the turbocharger control device of the present invention, when the turbocharger has a variable vane on the turbine side and the control means is configured to control the variable vane in the opening direction when the catalytic converter needs to be warmed up, the catalyst When the converter needs to be warmed up, the flow rate of the exhaust gas that passes through the turbine of the turbocharger decreases, and the exhaust heat energy acting on the turbine decreases. It becomes possible to warm up efficiently in a short time.

  Furthermore, in the turbocharger control device of the present invention, the control means controls the opening degree of the bypass control valve installed in the bypass pipe that communicates the downstream side and the upstream side of the compressor of the turbocharger. When it is configured to control the supercharging pressure by the target supercharging pressure, an excessive increase in the supercharging pressure by the compressor is suppressed, and the amount of compressed air supplied to the engine is reduced. The amount of exhaust discharged from the engine to the exhaust pipe is also reduced, and the temperature of the exhaust gas is increased accordingly, so that the catalytic converter can be warmed up more efficiently in a shorter time.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS A preferred embodiment of a turbocharger control device according to the invention will be described below with reference to the accompanying drawings. In this description, the same or similar components are denoted by the same reference numerals, and redundant description may be omitted. Here, FIG. 1 of the attached drawings is a schematic diagram showing a schematic configuration of the turbocharger control device according to the first embodiment of the present invention, and FIG. 2 is a flowchart showing a processing procedure of the turbocharger control device according to the first embodiment. is there.

  First, the turbocharger control device according to the first embodiment will be described. The turbocharger control apparatus according to the first embodiment is a control apparatus for a turbocharger 2 attached to a fuel injection type engine 1 as shown in FIG.

  The turbocharger 2 shown in FIG. 1 is installed in the middle of a turbine 2A installed in the exhaust pipe 3 connected to the exhaust manifold 1A of the engine 1 and in the intake pipe 4 connected to the intake manifold 1B of the engine 1. A compressor 2B, a shaft 2C for transmitting the rotation of the turbine 2A to the compressor 2B, and a motor generator (motor / generator) 2D as an electric motor that can be rotationally driven using the shaft 2C as a rotor.

  On the inlet side of the turbine 2 </ b> A of the turbocharger 2, the exhaust heat energy acting on the turbine 2 </ b> A is increased or decreased by variably adjusting the flow velocity (pressure) of the exhaust flowing from the exhaust manifold 1 </ b> A of the engine 1 through the exhaust pipe 3. A group of variable vanes 2E for the purpose is incorporated. In the middle of the exhaust pipe 3 downstream of the turbine 2 </ b> A of the turbocharger 2, a catalytic converter 5 containing a catalyst for purifying exhaust gas is installed.

  On the other hand, an air cleaner 6 is installed in the middle of the suction pipe 4 upstream of the compressor 2B of the turbocharger 2. Further, an intercooler 7 for cooling the intake gas that has been compressed by the compressor 2B and raised in temperature is installed in the middle of the suction pipe 4 on the downstream side of the compressor 2B of the turbocharger 2, and an actuator (not shown) is provided on the downstream side. An electronically controlled throttle valve 8 operated by the above is installed.

  A bypass pipe 10 having a bypass control valve 9 is connected between the downstream portion of the intercooler 7 in the suction pipe 4 and the upstream portion of the compressor 2B. The bypass pipe 10 avoids the surge phenomenon of the turbocharger 2 by returning the compressed air downstream of the intercooler 7 to the upstream side of the compressor 2B according to the opening degree of the bypass control valve 9.

  Here, the turbocharger control device of the first embodiment includes a turbocharger ECU (Electric Control Unit) 20 that functions as a control means. The turbocharger ECU 20 includes an input / output interface I / O, an A / D converter, a ROM (Read Only Memory) that stores programs and data, a RAM (Random Access Memory) that temporarily stores input data and the like, and a CPU ( Central Processing Unit) etc.

  The turbocharger ECU 20 is input from a catalyst temperature sensor 21, an upstream exhaust pressure sensor 22, a downstream exhaust pressure sensor 23, a supercharging pressure sensor 24, an airflow sensor 25, a throttle opening sensor 26, and an engine speed sensor 27. Based on the detected signal, a predetermined control signal is output to the MG (motor generator) controller 30, the VV (variable vane) controller 31, and the BV (bypass control valve) controller 32.

  The catalyst temperature sensor 21 is attached to the catalyst converter 5 so as to indirectly detect the temperature of the catalyst built in the catalyst converter 5. The catalyst temperature sensor 21 measures the temperature of the catalytic converter 5 and outputs a detection signal of the measured temperature Tc to the turbocharger ECU 20.

  The upstream exhaust pressure sensor 22 is installed in the exhaust inflow portion or the exhaust pipe 3 upstream of the variable vane 2E of the turbocharger 2. The upstream exhaust pressure sensor 22 detects the pressure of the exhaust gas flowing through the installation site, and outputs a detection signal of the exhaust pressure Pgu to the turbocharger ECU 20.

  On the other hand, the downstream exhaust pressure sensor 23 is installed in the exhaust pipe 3 between the exhaust outlet portion downstream of the turbine 2 </ b> A of the turbocharger 2 or the catalytic converter 5. The downstream exhaust pressure sensor 23 detects the pressure of exhaust flowing through the installation site, and outputs a detection signal of the exhaust pressure Pgl to the turbocharger ECU 20.

  The supercharging pressure sensor 24 is installed in the suction pipe 4 downstream of the throttle valve 8, detects the supercharging pressure of the compressed air flowing through the installation site, and sends a detection signal of the supercharging pressure Pb to the turbocharger ECU 20. Output.

  The airflow sensor 25 is installed in the suction pipe 4 on the downstream side of the throttle valve 8, detects the intake air amount of the compressed air flowing through the installation site, and sends a detection signal of the intake air amount Q to the turbocharger ECU 20. Output.

  The throttle opening sensor 26 detects the opening of the throttle valve 8 and outputs a detection signal of the opening θ to the turbocharger ECU 20. The engine speed sensor 27 detects the speed of the output shaft of the engine 1 and outputs a detection signal of the speed Ne to the turbocharger ECU 20.

  The MG controller 30 rotationally drives the motor generator 2D of the turbocharger 2 using the in-vehicle battery 33 connected thereto as a power source. The MG controller 30 supplies the electric power regenerated by the motor generator 2D to the in-vehicle battery 33. As a circuit for that purpose, the MG controller 30 includes an inverter and a DC-DC converter.

  When an engine speed control signal for driving the motor generator 2D at the target engine speed Nt_trg is input from the turbocharger ECU 20, the MG controller 30 supplies a predetermined drive current from the in-vehicle battery 33 to the motor generator 2D. Then, the motor generator 2D is driven at the target rotational speed Nt_trg. In addition, when a regenerative control signal is input from the turbocharger ECU 20, the MG controller 30 supplies the electric power generated by the motor generator 2 </ b> D to the in-vehicle battery 33.

  When a predetermined opening degree control signal is input from the turbocharger ECU 20, the VV controller 31 outputs a predetermined control current corresponding to the opening degree control signal to the motor actuator 34. Then, the motor actuator 34 operates according to a predetermined control current input from the VV controller 31, thereby rotating the group of variable vanes 2E of the turbocharger 2 simultaneously through an appropriate link mechanism. The group of variable vanes 2E adjusts the opening degree of the variable nozzle formed between the variable vanes 2E to a predetermined opening degree according to the opening degree control signal output from the turbocharger ECU 20. Exhaust energy acting on 2A is increased or decreased.

  When a predetermined opening degree control signal is input from the turbocharger ECU 20, the BV controller 32 outputs a predetermined control current corresponding to the opening degree control signal to the motor actuator 35. The motor actuator 35 operates in accordance with a predetermined control current input from the BV controller 32, whereby the opening degree of the bypass control valve 9 is determined according to an opening degree control signal output from the turbocharger ECU 20. Adjust to.

  Here, the turbocharger ECU 20 cooperatively controls the operation of the motor generator 2D of the turbocharger 2, the group of variable vanes 2E, and the bypass control valve 9 on the bypass pipe 10 when the above-described catalytic converter 5 needs to be warmed up.

  Hereinafter, the cooperative control processing procedure executed by the turbocharger ECU 20 in the turbocharger control device of the first embodiment will be described with reference to the flowchart shown in FIG.

  First, in step S10, the turbocharger ECU 20 determines whether or not the catalytic converter 5 needs to be warmed up based on the detection signal of the measured temperature Tc of the catalytic converter 5 input from the catalyst temperature sensor 21. This determination is made by comparing the target temperature Tc_trg previously stored in the ROM or the like as the temperature of the catalytic converter 5 corresponding to the catalyst activation temperature with the measured temperature Tc.

  If the decision result in the step S10 is YES, the turbocharger ECU 20 outputs a fully open opening degree control signal to the VV controller 31 in a succeeding step S11. As a result, the VV controller 31 outputs a predetermined control current to the motor actuator 34 to rotate the group of variable vanes 2E of the turbocharger 2 all at once until they are fully opened. As a result, the opening of the variable nozzle formed between the variable vanes 2E is adjusted to full open, the exhaust pressure Pgu upstream of the turbine 2A of the turbocharger 2 decreases, and the flow velocity of the exhaust gas passing through the turbine 2A decreases. As a result, the exhaust heat energy acting on the turbine 2A is reduced.

  In the next step S12, based on the upstream exhaust pressure Pgu detection signal input from the upstream exhaust pressure sensor 22 and the downstream exhaust pressure Pgl detection signal input from the downstream exhaust pressure sensor 23, the upstream side The turbocharger ECU 20 outputs a control signal for the target rotational speed Nt_trg to the MG controller 30 so as to reduce the pressure difference (Pgu−Pgl) between the exhaust pressure Pgu of the engine and the downstream exhaust pressure Pgl within a predetermined range as close to zero as possible. To do. As a result, the MG controller 30 controls the rotational speed of the motor generator 2D to rotationally drive the turbine 2A at the target rotational speed Nt_trg, and the pressure difference (Pgu−Pgl) between the upstream exhaust pressure Pgu and the downstream exhaust pressure Pgl. ) Within a predetermined range as close to zero as possible.

  Here, the pressure difference (Pgu−Pgl) between the exhaust pressure Pgu upstream of the turbine 2A of the turbocharger 2 and the exhaust pressure Pgl downstream, that is, the pressure difference between the exhaust inflow pressure Pgu and the exhaust outflow pressure Pgl of the turbine 2A. As (Pgu−Pgl) is smaller, the resistance of the turbine 2A to the exhaust flow is reduced, and the exhaust heat energy for rotating the turbine 2A is reduced. In other words, as shown in FIG. 3, the exhaust heat energy consumed by the turbine 2A decreases as the pressure difference (Pgu−Pgl) decreases.

  Therefore, in the process of step S12 described above, as shown in FIG. 4, the rotational speed Nt of the turbine 2A is controlled from Nt_0 in a state where the motor generator 2D is not driven to the target rotational speed Nt_trg by driving the motor generator 2D. As a result, the pressure difference (Pgu−Pgl) between the exhaust inflow pressure Pgu and the exhaust outflow pressure Pgl of the turbine 2A is controlled to decrease within a predetermined range as close to zero as possible. The resistance is reduced and exhaust heat energy for rotating the turbine 2A is reduced, and consumption of the exhaust heat energy by the turbine 2A is suppressed.

  In the subsequent step S13, the turbocharger 2 is driven by the motor generator 2D to rotate the compressor 2B together with the turbine 2A, so that the supercharging pressure Pb is not excessively increased, so that the excessive pressure input from the supercharging pressure sensor 24 is avoided. Based on the detection signal of the supply pressure Pb, the turbocharger ECU 20 outputs a predetermined opening degree control signal to the BV controller 32. As a result, the BV controller 32 outputs a predetermined control current to the motor actuator 35 to adjust the opening of the bypass control valve 9 to a predetermined opening corresponding to the opening control signal output from the turbocharger ECU 20.

  As a result, the compressed air in the suction pipe 4 on the downstream side of the intercooler 7 is returned to the upstream side of the compressor 2B by the bypass pipe 10 according to the opening degree of the bypass control valve 9, and the excess air in the suction pipe 4 is returned. An excessive increase in the supply pressure is suppressed. As the amount of intake air supplied from the intake pipe 4 to the engine 1 via the intake manifold 1B decreases, the amount of exhaust discharged from the engine 1 to the exhaust pipe 3 via the exhaust manifold 1A also decreases. , Exhaust temperature rises.

  Here, when the determination result of step S10 described above is NO, the turbocharger ECU 20 executes control for operating the turbocharger 2 in the normal mode according to the operating state of the engine 1 (step S14).

  In the turbocharger normal mode control in step S14, the turbocharger ECU 20 sets the supercharging pressure Pb according to the operating state of the engine 1 based on the detection signal of the supercharging pressure Pb input from the supercharging pressure sensor 24. A predetermined opening degree control signal for controlling the supply pressure is output to the VV controller 31 and the BV controller 32, respectively. At this time, when the engine 1 is in the low speed rotation region and it is necessary to assist the rotation of the compressor 2B of the turbocharger 2, the turbocharger ECU 20 outputs a predetermined drive control signal to the MG controller 30.

  In step S14, the turbocharger ECU 20 detects the throttle opening θQ detection signal input from the throttle opening sensor 26, the intake air amount Q detection signal input from the airflow sensor 25, and the engine speed sensor 26. The operating state of the engine 1 is grasped based on the detection signal of the engine speed Ne input from. Then, the turbocharger ECU 20 searches the data map of the target supercharging pressure stored in advance corresponding to the operating state of the engine 1 to determine the target supercharging pressure corresponding to the operating state of the engine 1.

  Here, when the turbocharger ECU 20 outputs a predetermined opening degree control signal to the VV controller 31 in the process of step S <b> 14, the VV controller 31 outputs a predetermined control current to the motor actuator 34. When the motor actuator 34 simultaneously rotates the group of variable vanes 2E of the turbocharger 2, the opening of the variable nozzle formed between the group of variable vanes 2E is output from the turbocharger ECU 20. It is adjusted to a predetermined opening according to the control signal. As a result, the exhaust energy acting on the turbine 2A of the turbocharger 2 is appropriately increased or decreased, and the supercharging pressure Pb by the compressor 2B is controlled to the target supercharging pressure.

  In step S14, when the turbocharger ECU 20 outputs a predetermined opening control signal to the BV controller 32, the BV controller 32 outputs a predetermined control current to the motor actuator 35 to increase the opening of the bypass control valve 9. The predetermined opening degree is adjusted according to the opening degree control signal output from the turbocharger ECU 20. As a result, the compressed air in the suction pipe 4 on the downstream side of the intercooler 7 is returned to the upstream side of the compressor 2B by the bypass pipe 10 according to the opening degree of the bypass control valve 9, and the excess air in the suction pipe 4 is returned. An excessive increase in the supply pressure is suppressed, and the supercharging pressure Pb is controlled to the target supercharging pressure.

  Further, when the turbocharger ECU 20 outputs a predetermined drive control signal to the MG controller 30 in the process of step S14, the MG controller 30 rotationally drives the motor generator 2D of the turbocharger 2 at a predetermined rotation speed by using the on-vehicle battery 33 as a power source. To do. In this case, the rotation speed of motor generator 2D is controlled such that supercharging pressure Pb by compressor 2B becomes the target supercharging pressure.

  In the turbocharger 2 controlled by the turbocharger ECU 20 as described above, the turbine 2A is rotationally driven by the thermal energy of the exhaust discharged from the exhaust manifold 1A to the exhaust pipe 3 as the engine 1 is operated. At the same time, the compressor 2B is driven to rotate. The air drawn from the air cleaner 6 through the suction pipe 4 is pressurized by the compressor 2B, then cooled by the intercooler 7 and supercharged to the engine 1. At that time, the supercharging pressure Pb is controlled to a target supercharging pressure corresponding to the operating state of the engine 1.

  Here, in the turbocharger control device of the first embodiment, when the catalytic converter 5 needs to be warmed up when the measured temperature Tc of the catalytic converter 5 is lower than the target temperature Tc_trg, the turbocharger ECU 20 first opens the VV controller 31 to fully open. A degree control signal is output, and a group of variable vanes 2E of the turbocharger 2 are simultaneously rotated to a fully opened state by the motor actuator 34. As a result, the exhaust pressure Pgu on the upstream side of the turbine 2A of the turbocharger 2 decreases, the flow rate of the exhaust gas passing through the turbine 2A decreases, and the exhaust heat energy acting on the turbine 2A decreases.

  Further, the turbocharger ECU 20 outputs a control signal of the target rotational speed Nt_trg to the MG controller 30, and rotates the turbine 2A of the turbocharger 2 at the target rotational speed Nt_trg by the motor generator 2D. As a result, the pressure difference (Pgu−Pgl) between the exhaust inflow pressure Pgu and the exhaust outflow pressure Pgl on the turbine 2A side of the turbocharger 2 decreases within a predetermined range as close to zero as possible within a short time. The resistance of the turbine 2A to the flow is reduced, the exhaust heat energy for rotating the turbine 2A is reduced, and the consumption of the exhaust heat energy by the turbine 2A is suppressed.

  Further, the turbocharger ECU 20 outputs a predetermined opening degree control signal to the BV controller 32 and causes the motor actuator 35 to adjust the opening degree of the bypass control valve 9 to the predetermined opening degree. As a result, an excessive increase in the supercharging pressure in the suction pipe 4 on the downstream side of the compressor 2B is suppressed, and the amount of compressed air supplied to the engine 1 is reduced. The amount of exhaust exhausted also decreases, and the temperature of the exhaust increases accordingly.

  Therefore, according to the turbocharger control device of the first embodiment, exhaust gas having a sufficient temperature is quickly supplied to the catalytic converter 5 when the catalytic converter 5 needs to be warmed up, so that the catalytic converter 5 can be efficiently warmed up in a short time. The warm-up efficiency of the catalytic converter 5 can be greatly improved.

  In the turbocharger control device of the first embodiment, when the catalytic converter 5 needs to be warmed up, the group of variable vanes 2E are simultaneously rotated to the fully opened state. However, the actual measured temperature with respect to the target temperature Tc_trg of the catalytic converter 5 The larger the temperature difference of Tc, the larger the group of variable vanes 2E may be rotated in the opening direction.

  In this case, when the catalytic converter 5 needs to be warmed up, as the measured temperature Tc of the catalytic converter 5 is lower, the group of variable vanes 2E are rotated more greatly in the opening direction, so that the exhaust heat acting on the turbine 2A of the turbocharger 2 The energy is greatly reduced, and the exhaust heat energy supplied to the catalytic converter 5 is increased correspondingly. For this reason, the catalytic converter 5 having a low measured temperature Tc can be efficiently warmed up in a short time.

  Next, a turbocharger control device according to the second embodiment will be described. The turbocharger control device according to the second embodiment is a control device for a turbocharger 2 attached to a fuel injection type engine 1 as shown in FIG.

  Here, as shown in FIG. 5, a battery voltage sensor 36 that detects the voltage as the remaining battery level is attached to the in-vehicle battery 33. The detection signal of the actual measurement voltage Vm detected by the battery voltage sensor 36 is input to the turbocharger ECU 20.

  An exhaust sensor 37 that detects the amount of emissions (NOx, HC, CO, PM, etc.) in the exhaust flowing through the exhaust pipe 3 immediately downstream of the catalytic converter 5 is installed. A detection signal of the actually measured emission amount Em detected by the emission sensor 37 is inputted to the turbocharger ECU 20.

  The other components shown in FIG. 5 are the same as the components shown in FIG. 1, and therefore, the same reference numerals as those in FIG.

  Here, the turbocharger ECU 20 in the turbocharger control device of the second embodiment determines when the in-vehicle battery 33 needs to be charged, when the amount of emission exceeds a reference value, and when the catalyst converter 5 needs to be warmed up, respectively. When the amount exceeds the reference value, charging control of the in-vehicle battery 33 is stopped even when charging of the in-vehicle battery 33 is necessary. Then, when the catalytic converter 5 needs to be warmed up, control for promoting the warming up of the catalytic converter 5 is executed.

  Hereinafter, a control processing procedure executed by the turbocharger ECU 20 in the turbocharger control device of the second embodiment will be described with reference to a flowchart shown in FIG.

  First, in step S20, the turbocharger ECU 20 determines whether or not the in-vehicle battery 33 needs to be charged based on the detection signal of the actually measured voltage Vm of the in-vehicle battery 33 input from the battery voltage sensor 36. This determination is performed by comparing the lower limit voltage Vmin stored in advance in the ROM or the like as the lower limit value of the voltage of the in-vehicle battery 33 with the actually measured voltage Vm. When the actually measured voltage Vm is lower than the lower limit voltage Vmin, the in-vehicle battery 33 is It is determined that charging is necessary.

  If the decision result in the step S20 is YES, in a succeeding step S21, the turbocharger ECU 20 determines whether or not the emission amount is an increase over the reference value based on the detection signal of the actually measured emission amount Em inputted from the emission sensor 37. Judgment. This determination is performed by comparing a reference emission amount Er stored in advance in a ROM or the like as a reference value of the emission amount with an actually measured emission amount Em.

  Here, when the determination result of step S21 is NO, the process proceeds to step S23 via step S22. However, when the determination result of step S21 is YES and when the determination result of step S20 is NO, step S23 is performed as it is. Proceed to

  In step S22, the turbocharger ECU 20 outputs a charge command signal so that the in-vehicle battery 33 is charged by an alternator (not shown) attached to the engine 1 as an auxiliary machine. Thereby, the alternator starts power generation and charges the in-vehicle battery 33.

  In step S23, whether or not the catalytic converter 5 needs to be warmed up based on the detection signal of the measured temperature Tc of the catalytic converter 5 input from the catalyst temperature sensor 21 as in the processing of step S10 shown in FIG. The turbocharger ECU 20 determines whether or not.

  When the determination result of step S23 is YES, the processes of steps S24 to S26 are sequentially executed, and when the determination result of step S23 is NO, the process of step S27 is executed. Note that the processing content of steps S24 to S26 is the same as the processing content of steps S11 to S13 shown in FIG. 2, and the processing content of step S27 is the same as the processing content of step S14 shown in FIG. Therefore, detailed description of the processing contents of steps S24 to S27 is omitted.

  Here, according to the turbocharger control device of the second embodiment, since the turbocharger ECU 20 executes the processing of steps S23 to S26 shown in FIG. 6, as in the turbocharger control device of the first embodiment, the catalyst When the converter 5 needs to be warmed up, exhaust gas having a sufficient temperature can be quickly supplied to the catalytic converter 5 to efficiently warm up the catalytic converter 5 in a short time. Can be improved.

  In addition, in the turbocharger control device of the second embodiment, since the turbocharger ECU 20 executes the processes of steps S20 to S22 shown in FIG. 6, when the vehicle-mounted battery 33 needs to be charged, the actually measured emission amount Em becomes the reference emission. If the amount Er is less than the amount Er, the charging control of the in-vehicle battery 33 is executed, but if the actually measured emission amount Em increases to the reference emission amount Er or more, the charging control of the in-vehicle battery 33 is stopped.

  Therefore, according to the turbocharger control device of the second embodiment, when the actually measured emission amount Em increases to the reference emission amount Er or more, the alternator power generation is stopped to reduce the load on the engine 1 and the fuel consumption of the engine 1 The amount can be suppressed, and further deterioration of emission can be suppressed.

  In the turbocharger control device of the second embodiment, the turbocharger ECU 20 executes the turbine rotation drive process by the motor generator 2D in step S25 in a state where the charging control of the in-vehicle battery 33 shown in step S22 of FIG. 6 is stopped. In doing so, it is preferable to provide an upper limit value for the assist power supplied from the in-vehicle battery 33 to the motor generator 2D in order to reduce the consumption of the in-vehicle battery 33 as much as possible.

  FIG. 7 shows an example in which the upper limit value Wmax of the assist power W is set according to the emission amount E. As shown in the solid line graph in the figure, the assist power is within a range where the actually measured emission amount Em is equal to or larger than the reference emission amount Er. W is fixed to a predetermined upper limit value Wmax. In this case, consumption of the in-vehicle battery 33 due to the in-vehicle battery 33 supplying assist power to the motor generator 2D can be suppressed.

  FIG. 8 shows an example in which the upper limit value Wmax of the assist power W is set according to the remaining amount of the in-vehicle battery 33. As shown in the solid line graph in the figure, the remaining amount of the in-vehicle battery 33 is in a very small range. Thus, the assist power W is fixed to a predetermined upper limit value Wmax. In addition, the graph shown with a broken line in the figure has shown the electric power generation amount of the alternator. In this case, it is possible to avoid so-called battery exhaustion due to the vehicle-mounted battery 33 supplying assist power to the motor generator 2D.

  In addition, of the upper limit value Wmax of the assist power W set according to the amount of emission E as shown in FIG. 7 and the upper limit value Wmax of the assist power W set according to the remaining amount of the in-vehicle battery 33 as shown in FIG. Any smaller value may be used as the upper limit value Wmax of the assist power W.

  Subsequently, a turbocharger control device according to a third embodiment will be described. The turbocharger control device according to the third embodiment is a control device for the turbocharger 2 attached to the fuel injection type engine 1 shown in FIG. 5, similarly to the turbocharger control device of the second embodiment described above. .

Here, in the catalytic converter 5 shown in FIG. 5, the catalyst collects soot (carbon, PM) from the exhaust discharged from the engine 1, nitrogen oxide (NO _x ), sulfur component (S), and the like. Occlude. When the amount of soot (carbon, PM) collected or the amount of nitrogen oxide (NO _x ) or sulfur component (S) stored reaches the limit, the collected soot (carbon, PM) or the stored nitrogen Oxides (NO _x ) and sulfur components (S) are harmless components (CO ₂ , N ₂ ) by catalyst regeneration control (PM regeneration control, NOx reduction control, S regeneration control) separately executed by another ECU (not shown). ₂ , SO _x ) and released into the atmosphere.

  As means for executing such catalyst regeneration control (PM regeneration control, NOx reduction control, S regeneration control), as shown in FIG. 9, a catalyst for detecting the inlet temperature of the catalyst is provided on the inlet side of the catalytic converter 5. An inlet temperature sensor 40 is installed, and a catalyst outlet temperature sensor 41 for detecting the outlet temperature of the catalyst is installed on the outlet side of the catalytic converter 5.

  The exhaust pipe 3 immediately upstream and the exhaust pipe 3 immediately downstream of the catalytic converter 5 are provided with pressure outlets 42A and 42B, and these pressure outlets 42A and 42B are connected to the inlet side of the catalytic converter 5. A differential pressure sensor 42 is connected to detect the pressure difference between the exhaust pressure of the exhaust gas and the exhaust pressure on the outlet side.

  Further, an exhaust fuel addition valve 43 for adding fuel (HC) to the exhaust is installed in the exhaust pipe 3 upstream of the catalytic converter 5, and the exhaust air / fuel ratio is installed in the exhaust pipe 3 downstream of the catalytic converter 5. An exhaust air / fuel ratio sensor 44 for detecting (A / F) is installed.

  The other components shown in FIG. 5 are the same as the components shown in FIG. 1, and therefore, the same reference numerals as those in FIG.

  Here, the turbocharger ECU 20 in the turbocharger control device of the third embodiment determines when the in-vehicle battery 33 needs to be charged, when the catalyst regeneration condition of the catalytic converter 5 is met, and when the catalyst converter 5 needs to be warmed up. When the regeneration condition is met, the charging control of the in-vehicle battery 33 is stopped even when the in-vehicle battery 33 needs to be charged. Then, when the catalytic converter 5 needs to be warmed up, control for promoting the warming up of the catalytic converter 5 is executed.

The catalyst regeneration condition of the catalytic converter 5 refers to the start condition of the catalyst regeneration control (PM regeneration control, NOx reduction control, S regeneration control) described above. In PM regeneration control, the catalyst detected by the differential pressure sensor 42 is used. This is a condition where the pressure difference between the exhaust gas on the inlet side and the outlet side of the converter 5 exceeds a predetermined threshold value. Further, in the NOx reduction control, it means a condition in which the NOx emission amount calculated one by one by the NOx emission amount map according to the operating state of the engine 1 exceeds a predetermined threshold value. Furthermore, in the S regeneration control, it means a condition in which the SO _x emission amount calculated in proportion to the fuel consumption amount of the engine 1 exceeds a predetermined threshold value.

  Hereinafter, a processing procedure of control executed by the turbocharger ECU 20 in the turbocharger control device of the third embodiment will be described with reference to a flowchart shown in FIG.

  First, in step S30, whether or not the in-vehicle battery 33 needs to be charged based on the detection signal of the actually measured voltage Vm of the in-vehicle battery 33 input from the battery voltage sensor 36, as in the process of step S20 shown in FIG. The turbocharger ECU 20 determines whether or not.

  If the determination result in step S30 is YES, in the subsequent step S31, the turbocharger ECU 20 determines whether or not the state of the catalytic converter 5 is in a state that matches the catalyst regeneration condition, that is, whether or not the catalyst regeneration condition is met. judge. This determination is made based on a start command signal for catalyst regeneration control that is separately executed by another ECU (not shown). When this start command signal is input to the turbocharger ECU 20, the turbocharger ECU 20 is in a state where the catalyst regeneration condition is met. Is determined.

  Here, when the determination result of step S31 is NO, the process proceeds to step S33 via step S32. However, when the determination result of step S31 is YES and when the determination result of step S30 is NO, step S33 is performed as it is. Proceed to

  In step S32, the turbocharger ECU 20 outputs a charge command signal so that the in-vehicle battery 33 is charged by an alternator (not shown) attached as an auxiliary machine to the engine 1 as in the process of step S22 shown in FIG. . Thereby, the alternator starts power generation and charges the in-vehicle battery 33.

  In step S33, whether or not the catalytic converter 5 needs to be warmed up based on the detection signal of the actual temperature Tc of the catalytic converter 5 input from the catalyst temperature sensor 21 as in the process of step S10 shown in FIG. The turbocharger ECU 20 determines whether or not.

  When the determination result of step S33 is YES, the processes of steps S34 to S36 are sequentially executed, and when the determination result of step S33 is NO, the process of step S37 is executed. The processing contents of steps S34 to S36 are the same as the processing contents of steps S11 to S13 shown in FIG. 2, and the processing contents of step S37 are the same as the processing contents of step S14 shown in FIG. Therefore, detailed description of the processing contents of steps S34 to S37 is omitted.

  Here, according to the turbocharger control device of the third embodiment, since the turbocharger ECU 20 executes the processing of steps S33 to S36 shown in FIG. 10, the catalyst is the same as in the turbocharger control device of the first embodiment. When the converter 5 needs to be warmed up, exhaust gas having a sufficient temperature can be quickly supplied to the catalytic converter 5 to efficiently warm up the catalytic converter 5 in a short time. Can be improved.

  In addition, in the turbocharger control device of the third embodiment, since the turbocharger ECU 20 executes the processing of steps S30 to S32 shown in FIG. 10, the state of the catalytic converter 5 is changed to the catalyst when the in-vehicle battery 33 needs to be charged. When the regeneration condition is met, that is, when the catalyst regeneration condition is not met, charging control of the in-vehicle battery 33 is executed, but when the catalyst regeneration condition is met, charging control of the in-vehicle battery 33 is stopped.

  Therefore, according to the turbocharger control device of the third embodiment, when the state of the catalytic converter 5 matches the catalyst regeneration condition, power generation of the alternator is stopped to reduce the load on the engine 1 and the fuel consumption of the engine 1 Can be suppressed. For this reason, even when fuel is added to the exhaust pipe 3 from the exhaust fuel addition valve 43 or after-injection of fuel in the PM regeneration control, NOx reduction control, and S regeneration control described above, the fuel consumption can be minimized. .

  In the turbocharger control device of the third embodiment, the turbocharger ECU 20 executes the turbine rotation drive process by the motor generator 2D in step S35 in a state where the charge control of the in-vehicle battery 33 shown in step S32 in FIG. 10 is stopped. In doing so, it is preferable to provide an upper limit value for the assist power supplied from the in-vehicle battery 33 to the motor generator 2D in order to reduce the consumption of the in-vehicle battery 33 as much as possible.

  FIG. 11 shows an example in which the upper limit value Wmax of the assist power W is set according to the temperature difference of the measured temperature Tc with respect to the target temperature Tc_trg of the catalytic converter 5, and as shown by the solid line graph in the figure, (Tc_trg−Tc )> 0, that is, in a range where the measured temperature Tc is lower than the target temperature Tc_trg, the assist power W is fixed to a predetermined upper limit value Wmax. In this case, consumption of the in-vehicle battery 33 due to the in-vehicle battery 33 supplying assist power to the motor generator 2D can be suppressed.

  As shown in the solid line graph of FIG. 8, if the assist power W is fixed to a predetermined upper limit value Wmax when the remaining amount of the in-vehicle battery 33 is extremely small, the in-vehicle battery 33 supplies the assist power to the motor generator 2D. It is possible to avoid so-called battery exhaustion due to supply.

  The turbocharger control device according to the present invention is not limited to the above-described embodiments. For example, in the first to third embodiments, in the process of step S12 of FIG. 2, the process of step S25 of FIG. 6, and the process of step S35 of FIG. The assist electric power (driving electric power) supplied to can be set larger as the temperature difference of the measured temperature Tc with respect to the target temperature Tc_trg of the catalytic converter 5 is larger.

  In this case, the rotational speed of the turbine 2A can be quickly and surely controlled by the motor generator 2D to quickly supply the necessary exhaust heat energy to the catalytic converter 5, and the catalytic converter 5 whose measured temperature is low by Tc can be quickly reduced. It becomes possible to warm up efficiently.

  In the first to third embodiments, in the process of step S22 in FIG. 6 and the process of step S32 in FIG. 10 executed by the turbocharger ECU 20, the assist power supplied from the in-vehicle battery 33 to the motor generator 2D is actually measured for the in-vehicle battery. The voltage Vm may be set smaller as the remaining amount is lower. In this case, the lower the remaining amount of the in-vehicle battery 33, the lower the decrease in the remaining amount.

  Further, the assist power supplied from the in-vehicle battery 33 to the motor generator 2D may be set according to the cooling water temperature (or lubricating oil temperature) of the engine 1 as shown in FIG. In this case, in a state where the rotation speed of engine 1 is low and the cooling water temperature (or lubricating oil temperature) is also low, the assist power of motor generator 2D is set high, and the rotation speed of engine 1 is high and the cooling water temperature (or lubricating oil temperature) is also high. In the state, the assist power of the motor generator 2D is set low.

It is a schematic diagram which shows schematic structure of the turbocharger control apparatus which concerns on 1st Embodiment of this invention. It is a flowchart which shows the process sequence of the turbocharger control apparatus which concerns on 1st Embodiment. 2 is a graph showing a correlation between a pressure difference between an exhaust inflow pressure and an exhaust outflow pressure on the turbine side of the turbocharger shown in FIG. 1 and exhaust heat energy consumed by the turbine. It is a graph which shows the correlation with the rotation speed of the turbine of the turbocharger shown in FIG. 1, and the exhaust heat energy which a turbine consumes. It is a schematic diagram which shows schematic structure of the turbocharger control apparatus which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the process sequence of the turbocharger control apparatus which concerns on 2nd Embodiment. 6 is a graph showing an upper limit value of assist power of a motor generator (electric motor) set according to an emission amount detected by an emission sensor in FIG. 5. It is a graph which shows the upper limit of the assist electric power of the motor generator (electric motor) set according to the residual amount of the vehicle-mounted battery detected by the battery voltage sensor in FIG. It is a schematic diagram of the vicinity of the catalytic converter showing the catalyst regeneration control means in the turbocharger control device according to the third embodiment of the present invention. It is a flowchart which shows the process sequence of the turbocharger control apparatus which concerns on 3rd Embodiment. 6 is a graph showing an upper limit value of assist power of a motor generator (electric motor) set in accordance with a temperature difference of an actually measured temperature with respect to a target temperature of a catalytic converter detected by a catalyst temperature sensor in FIG. 5. It is a graph which shows the assist electric power of the motor generator (electric motor) set according to the cooling water temperature (or lubricating oil temperature) of an engine as other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Turbocharger, 2A ... Turbine, 2B ... Compressor, 2C ... Shaft, 2D ... Motor generator, 2E ... Variable vane, 3 ... Exhaust pipe, 4 ... Intake pipe, 5 ... Catalytic converter, 8 ... Throttle valve , 9 ... Bypass control valve, 10 ... Bypass pipe, 20 ... ECU, 21 ... Catalyst temperature sensor, 22 ... Upstream exhaust pressure sensor, 23 ... Downstream exhaust pressure sensor, 24 ... Supercharging pressure sensor, 25 ... Airflow sensor , 26 ... throttle opening sensor, 27 ... engine speed sensor, 30 ... MG controller, 31 ... VV controller, 32 ... BV controller, 33 ... vehicle battery, 34 ... motor actuator, 35 ... motor actuator.

Claims (9)

A turbocharger control device in which a turbine capable of controlling the rotational speed is disposed upstream of a catalytic converter of an engine exhaust system,
Control that determines when the catalytic converter needs to be warmed up, and controls the rotational speed of the turbine when the catalytic converter needs to be warmed up to reduce the pressure difference between the exhaust inlet pressure and the exhaust outlet pressure on the turbine side within a predetermined range A turbocharger control device comprising means.   The turbocharger includes an electric motor capable of rotationally driving the turbine, and the control means is configured to control the rotational speed of the turbine by the control of the electric motor. Turbocharger control device.   The turbocharger has a variable vane on the turbine side, and the control means is configured to control the variable vane in an opening direction when the catalytic converter needs to be warmed up. Or the turbocharger control device according to 2;   The turbocharger control device according to claim 3, wherein the control means is configured to control the variable vane to a fully open state when the catalytic converter needs to be warmed up.   The control means is configured to detect an actual temperature of the catalytic converter, and to control the variable vane in the opening direction as the temperature difference between the actual temperature and the target temperature of the catalytic converter increases. The turbocharger control device according to claim 3.   The control means controls a supercharging pressure by the turbocharger compressor by controlling an opening degree of a bypass control valve installed in a bypass pipe that communicates the downstream side and the upstream side of the turbocharger compressor. The turbocharger control device according to claim 1, wherein the turbocharger control device is configured to control the pressure.   The control means determines when the vehicle battery needs to be charged and when the emission amount exceeds a reference value, and when the emission amount exceeds the reference value, performs charge control of the vehicle battery corresponding to when the vehicle battery needs to be charged. The turbocharger control device according to any one of claims 2 to 6, wherein the turbocharger control device is configured to be stopped.   The control means determines when the on-board battery needs to be charged and when the catalyst regeneration condition of the catalytic converter is met, and when the catalyst regeneration condition of the catalytic converter is met, stops the on-board battery charging control corresponding to when the on-board battery needs to be charged The turbocharger control device according to any one of claims 2 to 6, wherein the turbocharger control device is configured as described above. The control means detects the measured temperature of the catalytic converter and the remaining amount of the in-vehicle battery, respectively, and sets the drive power of the motor to be larger as the temperature difference between the measured temperature and the target temperature of the catalytic converter is larger. The turbocharger control device according to claim 2, wherein the turbocharger control device is configured to set the drive power of the electric motor to be smaller as the amount is smaller.

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