JP2009035117A - Exhaust cleaning controller for internal combustion engine in hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently carry out catalyst activation or regeneration processing when an exhaust path 3 of a diesel engine 1 is provided with an exhaust cleaning device 22 configured by making a filter (DPF) for PM collection carry a NOx trap catalyst and an oxidation catalyst in a hybrid vehicle. <P>SOLUTION: Whether the operation of an engine is needed or not is decided on the basis of required driving force for vehicle traveling and the remaining capacity of a battery 50. Then, a cylinder control means (intake shut-off valve 6) for stopping a part of cylinders by stopping both the inflow/outflow of gas and the supply of fuel in each cylinder of the engine is used to determine and control the number of stop cylinders and the outputs of operating cylinders when the improvement of catalyst activation is required, NOx regeneration is required, PM regeneration or S poisoning regeneration is required according to those requirements, the required driving force and the remaining capacity. Also, the air-fuel ratio of exhaust discharged from the operating cylinders and flowing into the exhaust cleaning device 22 is controlled. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an exhaust purification control device for an internal combustion engine (particularly a diesel engine) in a hybrid vehicle.

  A compression ignition type internal combustion engine such as a diesel engine has attracted attention from the viewpoint of improving the fuel consumption rate or reducing CO2. As an exhaust emission control device for a diesel engine, an oxidation catalyst that oxidizes HC, CO (and PM) in exhaust gas, and a NOx trap catalyst that adsorbs NOx when the exhaust air-fuel ratio is lean are known. The NOx trap catalyst desorbs and purifies adsorbed NOx (that is, NOx regeneration) by periodically making the exhaust air-fuel ratio rich and reducing atmosphere before the NOx adsorption amount saturates. Further, since the purification performance of the NOx trap catalyst is deteriorated by poisoning with S (sulfur) contained in the fuel, the S poisoning is periodically released (ie, S poisoning regeneration) at a high temperature and in a stoichiometric atmosphere. Yes.

  On the other hand, particulate matter PM (Particulate Matter) is contained in the exhaust of a diesel engine, and a filter (DPF; Diesel Particulate Filter) for collecting PM is known. Since this DPF causes fuel consumption and power performance deterioration due to an increase in exhaust pressure caused by PM accumulation, it is necessary to periodically remove and collect (that is, regenerate PM) the collected PM. In recent years, an exhaust emission control device (catalyst DPF) in which the above-described oxidation catalyst and NOx trap catalyst are supported on this DPF to simultaneously reduce HC, CO, PM, and NOx contained in exhaust gas has been developed. It has been proposed (Patent Document 1).

  When this exhaust purification device is disposed in the exhaust passage, it is necessary to periodically perform the NOx regeneration, S poison regeneration, and PM regeneration in order to maintain good exhaust purification performance. In addition, when performing such regeneration processing, or in order to maintain good exhaust purification performance, it is necessary to control the exhaust temperature (exhaust purification device temperature) and exhaust air-fuel ratio appropriate for each situation. is there.

  As a method of raising the temperature of the exhaust gas purification device, some cylinders are stopped by cylinder control (stopping inflow and out of working gas and stopping fuel injection), and the remaining working cylinders per cylinder are stopped. The exhaust temperature is raised by increasing the load, and the amount of oxygen flowing into the exhaust purification device is estimated when performing such cylinder control to perform NOx regeneration, S poison regeneration, and PM regeneration. A method of determining the number of cylinders to stop based on the estimated oxygen amount has been proposed (Patent Document 2).

Further, in a hybrid vehicle using a diesel engine and a motor generator as a drive source, when a DPF is provided as an exhaust gas purification device for a diesel engine, the motor generator is switched to a generator operation on condition that power generation is necessary. A configuration has been proposed in which the DPF self-regenerates by operating the diesel engine at an output higher than the driving force necessary for traveling and maintaining the exhaust gas temperature flowing into the DPF above the oxidation combustion temperature of the PM (patent) Reference 3).
JP 2003-190793 A JP 2005-220880 A Japanese Patent No. 2585179

  When an exhaust purification device for simultaneously reducing HC, CO, PM, and NOx is disposed in the exhaust passage, the activity of the catalyst is improved (promoted) or maintained regularly to maintain its exhaust purification performance. Therefore, NOx regeneration, S poisoning regeneration, and PM regeneration need to be carried out, and it is necessary to control the exhaust temperature (exhaust purification device temperature) and the exhaust air / fuel ratio appropriate for each process.

  Specifically, the oxidation activity of HC and CO is lean at about 200 ° C. or more, the adsorption activity of NOx is lean in the range of about 200 to 500 ° C., and the NOx regeneration is rich in the range of about 250 to 450 ° C. (λ ≦ 0). .8) S poison regeneration is stoichiometric or rich at about 600 ° C. or higher (λ ≦ 1), and PM regeneration is lean at about 400 ° C. or higher with catalyst (600 to 700 ° C. or higher without catalyst). It works most effectively when it is controlled.

  Further, in Patent Document 2, when some cylinders are stopped to raise the temperature, the intake / exhaust amount per cylinder of the remaining working cylinders increases, exhaust pulsation increases, and flows into the exhaust purification device. The amount of oxygen also pulsates and the peak value rises, and the reaction of HC and the like is promoted, which may cause an excessive temperature rise in the exhaust purification device.

  However, in the research by the present inventors, the processing such as catalyst activity improvement and PM regeneration is performed in a state where the exhaust air-fuel ratio is lean, so that the oxygen concentration remaining in the exhaust gas is high and the amount of oxygen is large. . On the other hand, since processing such as NOx regeneration and S poisoning regeneration is performed in a state where the exhaust air-fuel ratio is stoichiometric or rich, oxygen remaining in the exhaust does not theoretically exist and is actually extremely low. It exists only in concentration.

  Therefore, when processing such as catalyst activity improvement or PM regeneration is performed, although the oxygen concentration flowing into the exhaust purification device is relatively high and large in volume, some cylinders are stopped and the remaining working cylinders are stopped. When the load is increased, in the case of a naturally-charged engine, the change in the air filling rate due to the load is small and the increase in the exhaust pulsation peak is not so large. As the oxygen concentration decreases and the oxygen concentration decreases, the amount of oxygen also decreases.

  On the other hand, even in the case of an engine with a supercharger, if the load increases, the fuel injection amount increases and the exhaust temperature rises. Therefore, in order to increase the supercharging effect, the intake / exhaust amount per cylinder of the working cylinder is To increase. However, since the increase in the fuel injection amount accompanying the increase in the load exceeds the increase in the air filling rate due to supercharging, the excess air rate decreases and the oxygen concentration decreases, so the oxygen amount also decreases. Further, since the combustion temperature rises and the amount of HC decreases, even in the case of processing such as improvement of catalyst activity or PM regeneration, the reaction of HC or the like is promoted by the cylinder stop control, although the exhaust temperature increases. This will not cause an excessive increase in the temperature of the exhaust gas purification device.

  The condition for causing the exhaust purification device to overheat is when PM regeneration is started and immediately after that the state shifts to a deceleration state. At this time, the oxygen concentration in the exhaust gas rises to close to the atmospheric concentration, and PM undergoes an oxidation reaction (reburning) in an instant. Therefore, when a large amount of PM accumulates in the exhaust gas purification device (DPF), an excessive temperature rise may occur. There is sex.

  However, in order to prevent such an excessive temperature increase due to abnormal combustion and to prevent deterioration of power performance and fuel consumption due to an increase in back pressure due to PM deposition, generally, the amount of PM deposited on the exhaust purification device (DPF) Is set to about several grams per liter of the exhaust purification device (DPF). In comparison with this, the amount of exhaust gas flowing into the exhaust purification device is, for example, several hundred times to several thousand times per minute, which is overwhelmingly larger than the PM combustion amount.

  Moreover, the oxygen concentration under exhaust conditions where the exhaust temperature is higher than the oxidation reaction temperature of PM (400 ° C. with catalyst, about 600 ° C. without catalyst) is as low as about 10% or less. Under these conditions, the cylinder is stopped. Regardless of whether or not it is implemented, the PM oxidation reaction is slow (generally, it takes several minutes to regenerate PM), and the temperature of the exhaust purification device (DPF) rises slightly due to the reaction heat of PM. It is. On the other hand, even if the PM regeneration starts and immediately shifts to the deceleration state, there is no problem as long as the PM accumulation amount is within the specified range. However, if a large amount of PM accumulates due to some trouble or the like, the transition to deceleration is performed in an instant, so it is difficult to prevent the occurrence of excessive temperature rise by detecting the oxygen concentration.

  Therefore, the number of cylinders to be stopped is determined based on the estimated amount of oxygen flowing into the exhaust purification device while performing cylinder control for the catalyst activity improvement, NOx regeneration, S poison regeneration, PM regeneration, and the like. It is meaningless to perform cylinder control so as to obtain appropriate exhaust purification device temperature and exhaust air-fuel ratio control in accordance with the state of the exhaust purification device or various regeneration processes to be performed and the required driving force. Should.

  In addition, the configuration described in Patent Document 3 is performed in a state where the remaining charge (SOC) of the battery is relatively small, that is, in a state where the battery is discharged to some extent and the generated power can be charged. .

  For this reason, when it is not necessary to charge the battery, the vehicle is operated by a motor generator, a diesel engine, or a combination of a diesel engine and a motor generator. The exhaust gas temperature that flows into the DPF after being operated cannot be maintained above the oxidation combustion temperature of PM, and PM accumulates on the DPF until the battery needs to be charged.

  As a result, there is a possibility that the amount of PM deposited on the DPF becomes excessive before the power generation operation capable of self-regeneration of the DPF is reached.

  In such a case, if a power generation operation capable of self-regeneration of the DPF is performed, the amount of generated heat may be excessive and the DPF may overheat. Also, if the battery is fully charged and the power generation operation is stopped during the regeneration of the DPF, a vicious cycle in which the amount of PM accumulated on the DPF becomes excessive is caused, and conversely, the power generation is continued until the regeneration of the DPF is completed. When the operation is performed, the battery may be overcharged.

  In view of such a situation, an object of the present invention is to provide an exhaust gas purification control device for an internal combustion engine capable of improving exhaust gas purification performance and improving efficiency of various regenerations in a hybrid vehicle.

  For this reason, in the hybrid vehicle, the present invention determines whether or not the internal combustion engine needs to be operated on the basis of the driving force necessary for traveling of the vehicle and the remaining amount of charge of the battery, and in the exhaust passage of the internal combustion engine. A request for an exhaust gas temperature or an exhaust air / fuel ratio based on the state of the exhaust gas purification device arranged is detected. Then, it is determined that the operation of the internal combustion engine is necessary by using cylinder control means capable of stopping some cylinders by stopping the inflow and outflow of gas and the fuel supply in each cylinder of the internal combustion engine. When the engine is operated, the number of stop cylinders and the output of the working cylinders according to the request for the exhaust temperature or the exhaust air-fuel ratio based on the state of the exhaust purification device, the required driving force, and the remaining charge amount, At the same time, the exhaust air-fuel ratio discharged from the working cylinder of the internal combustion engine and flowing into the exhaust purification device is controlled.

  According to the present invention, when it is determined that the operation of the internal combustion engine is necessary and the internal combustion engine is operated, the request based on the state of the exhaust purification device provided in the exhaust passage, and the driving force necessary for traveling of the vehicle, Since the number of stopped cylinders of the internal combustion engine, the load of the working cylinder, and the exhaust air / fuel ratio flowing into the exhaust purification device are appropriately controlled according to the remaining charge of the battery, the battery is charged or the exhaust purification is performed. It is possible to prevent the battery from being overcharged or overdischarged when performing a process aimed at improving or recovering the exhaust gas purification performance of the apparatus. In this case, the exhaust gas purification device does not overheat, and the exhaust gas purification performance is not impaired. In addition, the energy consumed for various processing controls, that is, the loss of fuel consumption can be minimized.

  Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

  FIG. 1 is a system configuration diagram showing an embodiment of an exhaust gas purification control device for an internal combustion engine (particularly a diesel engine) in a hybrid vehicle according to the present invention, and in particular, a parallel hybrid vehicle (Parallel Hybrid Electric Vehicle; P-). HEV).

  In FIG. 1, the hybrid vehicle travels with the power of a diesel engine 1 and a motor generator 53 (hereinafter referred to as “MG2”) that serves as both a vehicle drive motor and a power generator.

  The output of the diesel engine 1 is transmitted to a motor generator 51 (hereinafter referred to as “MG1”) for power generation, and a differential gear 54 is transmitted from a power transmission mechanism (for example, a continuously variable transmission with an electromagnetic clutch; CVT) 52 for vehicle travel. To the drive wheels 55a and 55b.

  When the vehicle is decelerated and braked, MG1 · 51 and MG2 · 53 are effectively used as generators, and the vehicle braking force is converted into electric energy and collected, and the battery 50 is charged.

  The output distribution of the diesel engine 1 for power generation and vehicle travel is controlled by the hybrid control unit 40. The hybrid control unit 40 also controls the supply of electric power from the battery 50 to the MGs 2 and 53 and, conversely, the recovery of regenerative electric power from the MGs 1 and 51 and the MG 2 and 53 to the battery 50 during deceleration.

  In order to monitor vehicle running (stop) information, the hybrid control unit 40 has a signal from the accelerator sensor 41 (L: an output signal proportional to the amount of depression of the accelerator pedal), a signal from the start key 42 (STA: Acc position and Signal corresponding to the ON position), signal from the shift lever position sensor 43 (SFT), signal from the brake operation switch 44 (BR), signal from the vehicle speed sensor 45 (vehicle speed V), signal from the remaining battery sensor 46 (remaining charge) SOC) or the like is input to determine whether or not the engine 1 needs to be started and output sharing is performed, and a start command and output sharing command are issued to the engine control unit 30. In accordance with the command, the engine control unit 30 sets the operating point of the diesel engine 1 and controls the start, stop, and output.

  Here, the characteristics of the operation region of the general diesel engine 1 will be roughly described in FIG.

  If the engine uses a power transmission mechanism such as CVT, for example, the engine performs shift control suitable for the driving state of the vehicle at that time, and follows the point ab-c-d-e line for output. appear.

  Point a is idling.

  Point b means a low output point at which sufficient catalytic activity can be obtained, and in region A below point b, the exhaust temperature flowing into an exhaust purification device to be described later is approximately 200 ° C. or less, so that sufficient catalytic activity is achieved. In order to obtain the above, it is necessary to assist in raising the temperature.

  Point c means the best fuel consumption point. Generally, the load factor is about 70 to 80%, the rotation speed is low to medium, and the exhaust temperature is about 400 ° C. A region F centering on the point c means a good fuel consumption region of the engine, and the exhaust temperature is in a range of about 300 to 500 ° C.

  Point d means the point where the maximum output is obtained in the fuel-efficient region F of the engine. Generally, the load factor is about 80 to 90%, the rotation speed is medium, and the exhaust purification device is About 500 ° C. is obtained as the exhaust gas temperature flowing in.

  The point e means the rated maximum output point of the engine, and the exhaust temperature flowing into the exhaust purification device is approximately 600 ° C. or higher.

  In the region D from the output point slightly below the point b to the point c, the exhaust temperature flowing into the exhaust purification device is approximately 200 to 400 ° C. However, in order to regenerate PM, it is necessary to increase the temperature rising assistance even for the DPF with catalyst.

  The region C from the output point slightly below the point b to the point d is a region where high NOx adsorption activity is obtained because the exhaust temperature flowing into the exhaust purification device is approximately 200 to 500 ° C.

  In the region E from the point c to the point e, the exhaust temperature flowing into the exhaust purification device is approximately 400 to 600 ° C. Therefore, if the DPF is configured with a catalyst, the PM collected in the DPF is reburned. Therefore, it is a temperature region suitable for PM regeneration.

  And the area | region B containing the said area | regions C, D, and E is an area | region from which the high oxidation activity is acquired since the exhaust gas temperature which flows in into an exhaust gas purification device is obtained about 200-600 degreeC. Further, in order to perform S poisoning regeneration, it is necessary to perform temperature increase assistance throughout this region.

  In the HEV diesel engine of the present invention, the engine is mainly operated in the fuel efficiency region F. However, the fuel efficiency is relatively high, high oxidation activity and high NOx adsorption activity are obtained, and NOx regeneration, PM regeneration, As long as the operation region is also suitable for S and S poisoning regeneration, the operation region may vary.

  Returning to FIG. 1, the exhaust system and the like of the diesel engine 1 will be described.

  The diesel engine 1 includes an exhaust purification post-treatment device 20 that purifies the exhaust gas of the engine in the exhaust passage 3. The exhaust purification post-treatment device 20 includes a diesel particulate filter (DPF) that collects particulate matter PM in exhaust gas, and a NOx trap catalyst (LNT; Lean that adsorbs NOx when the air-fuel ratio of the exhaust gas is lean). NOx Trap Catalyst) and an oxidation catalyst that oxidizes HC, CO (and PM) in the exhaust, and includes an exhaust purification device 22 that reduces HC, CO, PM, and NOx in the exhaust.

  DPF is a honeycomb structure made of porous ceramics, and a plurality of parallel cell spaces extending in the exhaust flow direction are adjacent to each other, one on the outlet side and the other on the inlet side, alternately with a sealing material. By sealing, the exhaust gas passes through the cell wall (its pores) and flows, and PM in the exhaust gas is collected by the cell wall.

  This DPF (particularly the surface of the cell wall facing the exhaust inflow side cell space) carries LNT and an oxidation catalyst.

  LNT adsorbs NOx in the exhaust when the exhaust air-fuel ratio is lean, and desorbs and purifies the adsorbed NOx when the exhaust air-fuel ratio is rich. As NOx adsorbents, Ba, Mg, Cs or the like is used.

  The oxidation catalyst oxidizes HC, CO (and PM) in the exhaust, and uses a noble metal such as Pt, Pd, Rh.

  Here, with respect to DPF, fuel consumption and power performance are deteriorated due to an increase in exhaust pressure caused by accumulation of collected PM. Therefore, the collected PM is periodically removed by combustion at high temperatures (that is, PM Need to play). Further, for LNT, it is necessary to desorb and purify (that is, NOx regeneration) the adsorbed NOx by periodically making the exhaust air-fuel ratio rich to make a reducing atmosphere before the NOx adsorption amount is saturated. In addition, since LNT also deteriorates the adsorption performance due to poisoning by S (sulfur) contained in the fuel, it is necessary to periodically release S poisoning (ie, S poison regeneration) at a high temperature and a stoichiometric atmosphere.

  Further, the exhaust purification post-treatment device 20 is a heating means for assisting the performance of the exhaust purification device 22 on the upstream side of the exhaust purification device 22, and an electric heating type for enhancing the catalyst performance in the exhaust purification post-treatment device 20. A catalyst (EHC) 21 is arranged. The EHC 21 is obtained by carrying an oxidation catalyst or a three-way catalyst on a metal carrier that can be energized.

  A temperature sensor 35 is provided at the inlet of the exhaust purification device 22 so as to be close to the exhaust purification device 22 and the EHC 21, and the EHC temperature when the engine 1 is stopped, and the exhaust temperature during operation of the engine 1, Detect as Tex. An oxygen concentration sensor 36 for detecting the oxygen concentration O2 is provided at the outlet of the exhaust purification device 22.

  A turbocharger turbine 3a is disposed in the middle of the exhaust passage 3 (upstream from the exhaust purification post-treatment device 20), and an EGR valve 5 is provided in the EGR passage 4 branched from the upstream. The EGR valve 5 is driven by an actuator such as a stepping motor, for example, and returns a part of the exhaust gas to the intake pipe 2 d of the intake passage 2.

  The intake passage 2 includes, from upstream, an air cleaner 2a, a supercharger compressor 2b, an intercooler 2c, an intake throttle valve 7 that is driven to open and close by an actuator such as a stepping motor, and an intake pipe 2d. In the branch pipe, there is provided an intake shut-off valve 6 that independently opens and closes each branch pipe by an actuator (for example, a stepping motor).

  Here, in order to stop the inflow / outflow of the working gas in the cylinder stop control, the simplest intake shutoff valve 6 is arranged in the present embodiment. However, as a method for stopping the inflow / outflow of the working gas, Regardless, a known valve timing variable mechanism that can arbitrarily control the valve timing may be applied to the valve operating mechanism of the intake valve (and the exhaust valve).

  The fuel supply system includes a fuel tank 60 for storing diesel fuel (light oil), a fuel supply passage 16 for supplying fuel from the fuel tank 60 to the fuel injection device 10 of the engine, and a return fuel from the fuel injection device 10 of the engine. A fuel return passage 19 for returning (spill fuel) to the fuel tank 60 is provided.

  The fuel injection device 10 of the diesel engine 1 is a well-known common rail type fuel injection device, and includes a supply pump 11, a common rail (accumulation chamber) 14, and a fuel injection valve 15 provided for each cylinder. The fuel pressurized by the supply pump 11 is temporarily stored in the common rail 14 through the fuel supply passage 12 in a high pressure state, and then distributed to the fuel injection valves 15 corresponding to the number of cylinders.

  The pressure of the common rail 14 is controlled by the pressure control valve 13. That is, the pressure control valve 13 has an overflow passage 17 that returns part of the fuel discharged from the supply pump 11 to the fuel supply passage 16 via the one-way valve 18 in response to a duty signal from the engine control unit 30. By changing the flow path area, the fuel discharge amount to the common rail 14 is adjusted, and the pressure of the common rail 14 is controlled.

  The fuel injection valve 15 is an electronic injection valve that opens and closes a fuel passage to the engine combustion chamber in response to an ON-OFF signal from the engine control unit 30, and injects fuel into the combustion chamber in response to an ON signal. To stop the injection. The fuel injection amount increases as the ON signal to the fuel injection valve 15 is longer and the fuel pressure of the common rail 14 is higher.

  Further, a glow plug 24 for assisting engine start is provided facing the combustion chamber of each cylinder of the diesel engine 1.

  The engine control unit 30 communicates with the hybrid control unit 40, the signal (Tw) of the water temperature sensor 31, the signal of the crank angle sensor 32 (engine rotational speed and crank angle detection Ne), and the signal of the cam angle sensor 33. (Cylinder discrimination signal Cyl), a signal (PCR) of the pressure sensor 34 for detecting the common rail pressure, a signal (Tex) of the temperature sensor 35, and a signal (O2) of the oxygen concentration sensor 36 are input. The specific control of the engine control unit 30 will be described later.

  The exhaust purification control apparatus of the present invention is controlled by the hybrid control unit 40 and the engine control unit 30, which will be described with reference to the flowcharts of FIGS.

  FIG. 8 is a basic control routine of the hybrid system, and FIGS. 9 to 18 are subroutines relating to the output control of the diesel engine 1 performed by the engine control unit 30 in accordance with a command from the hybrid control unit 40 and the exhaust purification control of the present invention. Indicates.

  In the basic control routine of the hybrid system of FIG. 8, in step 100, the signal (L) of the accelerator sensor 41, the signal (STA) of the start key 42, the signal (SFT) of the shift lever position sensor 43, the signal of the brake operation switch 44 (BR), a signal (V) of the vehicle speed sensor 45, a signal (SOC) of the battery remaining amount sensor 46, and a signal (Tw) of the water temperature sensor 31 and a signal of the crank angle sensor 32 (engine speed and crank angle detection). Ne), a signal from the cam angle sensor 33 (cylinder discrimination signal Cyl), a signal from the pressure sensor 34 that detects common rail pressure (PCR), a signal from the temperature sensor 35 that detects EHC temperature or exhaust temperature (Tex), and an oxygen concentration sensor 36 signal (O2) is read and the routine proceeds to step 200.

  In step 200, as shown in FIG. 2 to FIG. 6, the necessary driving force for driving the vehicle according to the depression amount (L) of the driver's accelerator pedal (Prun: the line at point ae in the figure), That is, the driving force required for vehicle travel (requested vehicle driving force Prun) calculated by the driver by the accelerator operation is calculated, and the process proceeds to step 110.

  In step 110, it is determined whether a regeneration process (S poisoning regeneration, PM regeneration, or NOx regeneration) to be described later is being performed. If this determination is Yes and the regeneration process is being performed, the process proceeds to step 400. On the other hand, if the determination is No and the regeneration process is not being performed (including the case where the catalyst activity is being improved), the process proceeds to step 120.

  In step 120, it is determined whether or not the engine is in a brake state (for example, a deceleration state such as when the accelerator pedal depression amount L is 0 but the vehicle speed V is not 0). If this determination is Yes, the process proceeds to step 300 to stop all the cylinders of the engine (stopping the working gas inflow and outflow and fuel injection), and the process proceeds to step 6000. If the determination is No, the process proceeds to step 400.

  In step 400, the driving pattern of the engine and motor generator (MG) for driving the vehicle is determined according to the subroutine of FIG.

  In step 130, it is determined whether or not the engine 1 needs to be operated (there is an engine sharing request). If this determination is No and engine operation is not required, the process proceeds to step 1000, and stop control of the engine 1 is performed according to a subroutine of FIG.

  That is, the hybrid control unit 40 issues a stop command to the engine control unit 30. The engine control unit 30 performs stop control of the engine 1 in accordance with the stop command.

  If the determination in step 130 is yes and the engine 1 needs to be operated, the process proceeds to step 140.

  In step 140, it is determined whether or not the engine 1 has already been started (engine is running). When this determination is Yes and the engine 1 is already in operation, that is, the output command has already been transmitted from the hybrid control unit 40 to the engine control unit 30, and the engine control unit 30 performs the engine operation according to the command. When the output control 1 is being performed, the process proceeds to step 900.

  In step 900, engine operation control is performed according to a subroutine shown in FIG. That is, for the purpose of S poison regeneration, PM regeneration, NOx regeneration, and improvement of catalyst activity, the number of cylinders that are activated (stopped) and the load (output) of the activated cylinders are determined and controlled, and In order to obtain the vehicle driving force (Prun) or the engine sharing output (Pe) determined in Step 200 and Step 400 described above, including exhaust air-fuel ratio control for controlling the exhaust air-fuel ratio to be discharged (inflow into the exhaust purification device) The output control of the engine 1 is continued or started.

  On the other hand, if the determination in step 140 is No and the engine 1 has not yet been started, the process proceeds to step 800 where start control of the engine 1 is performed (a start command is issued) according to a subroutine shown in FIG.

  This starting operation is also controlled by the hybrid control unit 40 and the engine control unit 30.

  After performing the engine operation control in step 900, the engine start operation control in step 800, and the engine stop operation control in step 1000, the process proceeds to step 6000.

  In step 6000, the hybrid control unit 40 performs power generation control using one or both of MG1 · 51 and MG2 · 53 based on the engine power generation output (Pdiv), which will be described later, determined in step 400, or during engine braking. Perform regenerative power generation control.

  In the next step 7000, a motor driving force (Pm) described later determined in step 400 is output using one or both of MG1 · 51 and MG2 · 53.

  In the final step 8000, speed ratio control and ON-OFF control of the power transmission mechanism 52 (for example, CVT with an electromagnetic clutch) are performed based on the drive pattern, vehicle speed (V), and the like.

  FIG. 9 is a flowchart showing a subroutine for determining the engine and MG drive patterns performed in step 400 (FIG. 8).

  In the drive pattern determination routine of FIG. 9, in step 410, it is determined that S poison regeneration of the exhaust purification device 22 is necessary by the S poison regeneration timing determination in step 500 described later, and an S poison regeneration command is issued. Judge whether it is.

  If YES in step 410 and S poisoning regeneration is necessary, the process proceeds to step 2000.

  In step 2000, target values for engine control (cylinder control, exhaust air-fuel ratio control) and MG drive control for S poisoning regeneration control and MG drive control are determined according to a subroutine shown in FIG.

  Then, the process proceeds to step 440, and it is determined whether the S poisoning regeneration is completed (for example, a predetermined time has elapsed). If NO in step 440 and S poisoning regeneration is not completed, the process returns. If YES and S poisoning regeneration is terminated, the process proceeds to step 450 and S poisoning regeneration end processing (for example, a regeneration command flag). It returns after performing OFF, playback time counter reset).

  If NO in step 410 and S poisoning regeneration is not necessary, the process proceeds to step 420.

  In step 420, it is determined by the PM regeneration timing determination in step 600 described later that PM regeneration of the exhaust purification device 22 is necessary, and it is determined whether a PM regeneration command is issued.

  If Yes in step 420 and PM regeneration is necessary, the process proceeds to step 3000.

  In step 3000, target values for engine control (cylinder control, exhaust air / fuel ratio control) and MG drive control for PM regeneration control are determined according to a subroutine shown in FIG.

  Then, the process proceeds to step 460, and it is determined whether PM regeneration has ended (for example, a predetermined time has elapsed). If NO in step 460 and PM regeneration has not ended, the process returns. If YES and PM regeneration has ended, the process proceeds to step 470, where PM regeneration end processing (for example, regeneration command flag OFF, regeneration time counter reset) ) To return.

  If No in step 420 and PM regeneration is not necessary, the process proceeds to step 430.

  In step 430, it is determined that NOx regeneration of the exhaust purification device 22 is necessary by NOx regeneration timing determination in step 700 described later, and it is determined whether a NOx regeneration command is issued.

  If YES in step 430 and NOx regeneration is necessary, the process proceeds to step 4000.

  In step 4000, target values for engine control (cylinder control, exhaust air-fuel ratio control) and MG drive control for NOx regeneration control are determined according to a subroutine shown in FIG.

  Then, the process proceeds to step 480, where it is determined whether the NOx regeneration is completed (for example, a predetermined time has elapsed). If NO in step 480 and NOx regeneration has not ended, the process returns. If NO and NOx regeneration has ended, the process proceeds to step 490, where NOx regeneration end processing (for example, regeneration command flag OFF, regeneration time counter reset). ) To return.

  If NO in step 430 and NOx regeneration is not necessary, the process proceeds to step 5000.

  In step 5000, target values for engine control (cylinder control, exhaust air / fuel ratio control) and MG drive control for catalyst activity improvement control are determined according to a subroutine shown in FIG.

  In step 500, the S poisoning regeneration time determination of the exhaust purification device 22 is performed. Here, the S poisoning regeneration time determination is performed by searching from predetermined data stored in the ROM of the control unit 30 in advance using, for example, the engine speed Ne and the fuel injection amount Qmain as parameters, and purifying exhaust gas per unit time. The amount of S poisoning of the device 22 is obtained, integrated, and it is determined whether or not the accumulated amount of S poisoning exceeds a predetermined S poisoning limit amount. It is possible to determine whether this is a necessary time.

  After performing the S poisoning regeneration time determination of the exhaust purification device 22 in step 500, the process proceeds to step 600.

  In step 600, the PM regeneration timing of the exhaust purification device 22 is determined. Here, the PM regeneration timing determination is performed by searching from predetermined data stored in the ROM of the control unit 30 in advance using, for example, the engine rotational speed Ne and the fuel injection amount Qmain as parameters, and the exhaust purification device 22 per unit time. PM regeneration amount (deposition amount) is obtained, and this is integrated, and PM regeneration is determined by determining whether the integrated PM collection amount exceeds a predetermined collection limit amount (PM oxidation combustion removal) It is possible to determine whether this is a necessary time.

  After determining the PM regeneration timing of the exhaust purification device 22 in step 600, the process proceeds to step 700.

  In step 700, the NOx regeneration timing of the exhaust purification device 22 is determined, and the process returns. Here, the NOx regeneration timing determination is performed by searching from predetermined data stored in the ROM of the control unit 30 in advance using, for example, the engine speed Ne and the fuel injection amount Qmain as parameters, and the exhaust purification device 22 per unit time. This is the time when NOx regeneration (NOx desorption reduction purification) is necessary by determining the NOx adsorption amount of the NOx, integrating the NOx adsorption amount, and determining whether the accumulated NOx adsorption amount exceeds a predetermined adsorption limit amount. Can be determined.

  FIG. 10 shows engine control, exhaust air-fuel ratio control, cylinder control, and MG drive for S poison regeneration (stoichiometric combustion control, λ ≦ 1) of the exhaust purification device 22 performed in the above-described step 2000 (FIG. 9). It is a flowchart which shows the subroutine for determining the target value of control.

  In the S poisoning regeneration target value determination routine of FIG. 10, in step 2100, in accordance with the subroutine of FIG. 12 described later, a cylinder stop pattern common to S poisoning regeneration and PM regeneration, the output of the engine operating cylinder, and the MG output or power generation An output target value (cylinder control pattern A) is determined, and the process proceeds to step 2600.

  In step 2600, predetermined data set in advance corresponding to the rotational speed Ne and the working cylinder output Pe ′ is searched, and the main injection amount Qmain and the main injection timing ITmain for performing the main injection control of the working cylinder are obtained. And go to step 2700.

  In step 2700, predetermined data set in advance corresponding to the rotational speed Ne and the output Pe ′ of the working cylinder is retrieved, and the post injection amount Qpost and post for the purpose of performing the post injection for the purpose of S-poisoning regeneration. The injection timing ITpost is obtained and the process proceeds to step 2800.

  In step 2800, an EGR target value (driving signal for the EGR valve 5) aimed at S poison regeneration in addition to the exhaust control is obtained, and the process proceeds to step 2900.

  In step 2900, in addition to the exhaust control, an intake throttle target value (drive signal for the intake throttle valve 7) for the purpose of S poison regeneration is obtained, and the process returns.

  As will be described later, the exhaust temperature flowing into the exhaust purification device is about 250 ° C. or higher, particularly when the temperature rise for regeneration and the exhaust control are not performed and the cylinder stop control is not performed. When the cylinder control pattern A, which will be described later, determined in the S poisoning regeneration target value determination routine, is performed, the exhaust temperature flowing into the exhaust purification device is about 400 ° C. or higher. Accordingly, it is possible to reduce the enhancement of post-injection, EGR, intake throttle, etc., which are determined to assist the temperature increase for the above-described S poisoning regeneration, and to reduce the deterioration of fuel consumption caused by the S poison regeneration. .

  FIG. 11 determines target values for engine control, exhaust air-fuel ratio control, cylinder control, and MG drive control for PM regeneration (lean combustion control) of the exhaust purification device 22 performed in the above-described step 3000 (FIG. 9). It is a flowchart which shows the subroutine for performing.

  In the PM regeneration target value determination routine of FIG. 11, in step 2100, the cylinder stop pattern common to S poison regeneration and PM regeneration, the output of the engine operating cylinder, and the MG output or power generation output are determined in accordance with the subroutine of FIG. A target value (cylinder control pattern A) is determined, and the process proceeds to step 3100.

  In step 3100, predetermined data set in advance corresponding to the rotational speed Ne and the output Pe ′ of the working cylinder is retrieved, and the main injection amount Qmain and the main injection timing ITmain for performing the main injection control of the working cylinder are obtained. And go to step 3200.

  In step 3200, predetermined data set in advance corresponding to the rotational speed Ne and the output Pe ′ of the working cylinder is retrieved, and the post injection amount Qpost and post injection timing for performing post injection for the purpose of PM regeneration. Determine ITpost and go to step 3300.

  In step 3300, in addition to exhaust control, an EGR target value (drive signal for the EGR valve 5) for the purpose of PM regeneration is obtained, and the process proceeds to step 3400.

  In step 3400, in addition to exhaust control, an intake throttle target value (drive signal for the intake throttle valve 7) for the purpose of PM regeneration is obtained, and the process returns.

  Further, as in the case of the S poisoning regeneration, by performing a cylinder control pattern A, which will be described later, determined in the PM regeneration target value determination routine, the exhaust temperature flowing into the exhaust purification device is about 400 ° C. or more. If the DPF with catalyst is obtained, the PM reburning temperature can be obtained. Therefore, the post-injection, EGR, intake air throttle, and the like that are determined to assist the temperature increase for the above-described PM regeneration can be stopped slightly even if implemented, but if there is no catalyst, it is appropriate. Therefore, it is desirable to change each set target value depending on the presence or absence of a catalyst.

  FIG. 12 is a flowchart showing a subroutine for determining a cylinder control pattern A common to S poisoning regeneration and PM regeneration performed in step 2100 (FIGS. 10 and 11) described above.

  The cylinder control pattern A determination routine of FIG. 12 will be described with reference to the characteristic diagrams shown in FIGS. In this embodiment, the engine is configured as a four-cylinder engine.

  In step 2110, it is determined whether the vehicle driving force Prun is equal to or greater than the set maximum output when the cylinder stop shown as Pe5 in FIGS. 2 to 6 is not performed. If yes, the process proceeds to step 2160.

  In step 2160, the output to be generated by each cylinder of engine 1 and MG2 · 53 is determined as follows. Then, in step 2300, the cylinder control pattern 0, that is, the four-cylinder operation is determined and a return is made.

Each cylinder output Pe ′ = Pemax → 4 × Pemax = Pe5
Motor output Pm = Prun-Pe5
Here, Pe5 corresponds to each cylinder output Pemax at the point d in FIG. 7, and the exhaust temperature is about 500 ° C. in the normal operation without performing the temperature increase or exhaust control for each regeneration.

  If No in step 2110, the process proceeds to step 2120, where it is determined whether the vehicle driving force Prun is equal to or higher than the best fuel consumption setting output when the cylinder stop shown as Pe4 in FIGS. Proceeding to step 2170, it is determined whether the remaining charge (SOC) of the battery 50 is higher than a predetermined value SOC1 at which stable power can be supplied. If yes, the process proceeds to step 2180. Proceed to step 2190.

  In step 2180, each cylinder of engine 1 and the output to be generated by MG2 · 53 are determined as follows. In step 2300, cylinder control pattern 0 is determined.

Each cylinder output Pe ′ = Pemed → 4 × Pemed = Pe4
Motor output Pm = Prun-Pe4
In step 2190, the output to be generated by each cylinder of the engine 1 is determined as follows, and the surplus output of the engine 1 is applied to the power generation of the MG1 · 51 and MG2 · 53. In step 2300, the cylinder control pattern 0 is determined.

Each cylinder output Pe ′ = Pemax → 4 × Pemax = Pe5
Power generation output Pdiv = Pe5-Prun
Here, Pe4 corresponds to each cylinder output Pemed at point c, which is the best fuel consumption setting point in FIG. 7, and the exhaust temperature is about 400 ° C. in the normal operation without performing the temperature increase or exhaust control for each regeneration. It is done.

  If NO in step 2120, the process proceeds to step 2130, and the vehicle driving force Prun exceeds the set output corresponding to the aforementioned Pemed when the one-cylinder stop (three-cylinder) operation shown as Pe7 in FIGS. If yes, the process proceeds to step 2140, where it is determined whether the remaining charge (SOC) of the battery 50 is higher than the predetermined value SOC1, and if yes, the process proceeds to step 2150 and No. If yes, go to Step 2200.

  In step 2150, the output to be generated by each cylinder of engine 1 and MG2 · 53 is determined as follows. In step 2400, the cylinder control pattern 1, that is, the one-cylinder stop (three-cylinder) operation is determined and the process returns.

Each cylinder output Pe ′ = Pemed → 3 × Pemed = Pe7
Motor output Pm = Prun-Pe7
In step 2200, the output to be generated by each cylinder of the engine 1 is determined as follows, and the surplus output of the engine 1 is applied to the power generation of the MG1 · 51 and MG2 · 53. In step 2300, the cylinder control pattern 0 is determined.

Each cylinder output Pe ′ = Pemed → 4 × Pemed = Pe4
Power generation output Pdiv = Pe4-Prun
If NO in step 2130, the process proceeds to step 2210, where the vehicle driving force Prun exceeds the set output corresponding to the aforementioned Pemed when the two-cylinder stop (two-cylinder) operation shown as Pe6 in FIGS. If yes, the process proceeds to step 2220, where it is determined whether the remaining charge (SOC) of the battery 50 is higher than the predetermined value SOC1, and if yes, the process proceeds to step 2230 and No. If so, go to Step 2240.

  In step 2230, each cylinder of engine 1 and the output to be generated by MG2 · 53 are determined as follows. In step 2500, the cylinder control pattern 2, that is, the two-cylinder stop (two-cylinder) operation is determined and the process returns.

Each cylinder output Pe ′ = Pemed → 2 × Pemed = Pe6
Motor output Pm = Prun-Pe6
In step 2240, the output to be generated by each cylinder of the engine 1 is determined as follows, and the surplus output of the engine 1 is applied to the power generation of the MG1 · 51 and MG2 · 53. In step 2400, the cylinder control pattern 1 is determined.

Each cylinder output Pe ′ = Pemed → 3 × Pemed = Pe7
Power generation output Pdiv = Pe7-Prun
If NO in step 2210, the process proceeds to step 2250, where the output to be generated by each cylinder of the engine 1 is determined as follows, and the surplus output of the engine 1 is applied to the power generation of the MG1, 51, MG2, 53. In step 2500, the cylinder control pattern 2 is determined.

Each cylinder output Pe ′ = Pemed → 2 × Pemed = Pe6
Power generation output Pdiv = Pe6-Prun
Here, the minimum value of the vehicle driving force Prun in the cylinder control pattern A is set to Pe6 regardless of the level of the remaining charge (SOC) of the battery 50. When the required driving force Prun is equal to or less than Pe6, S poisoning regeneration or PM The surplus output (Pdiv = Pe6-Prun) continues to be applied to charging the battery 50 until the reproduction is completed. Pe6 corresponds to the above-mentioned Pemed when the two-cylinder stop (two-cylinder) operation is performed, but when the four-cylinder operation is performed, the point b in FIG. The exhaust temperature flowing into the exhaust purification device at the low output point obtained corresponds to about 250 ° C.).

  On the other hand, by performing cylinder stop control, the exhaust temperature flowing into the exhaust purification device can be about 400 ° C. or higher. Therefore, at the time of S poisoning regeneration and PM regeneration, it is possible to reduce the enhancement of post injection, EGR, intake throttle, etc., which are determined to assist in raising the temperature. In particular, in the case of a DPF with a catalyst, the enhancement of post injection, EGR, intake throttle, etc., which are determined to assist in raising the temperature during PM regeneration, can be minimized. In addition, since each cylinder output for obtaining Pe4, Pe7, and Pe6 is based on Pemed of the best fuel efficiency point, it is possible to minimize deterioration in fuel efficiency caused by performing S poisoning regeneration or PM regeneration.

  In addition, since the minimum value of the vehicle driving force Prun until the end of regeneration can be set to a low output, that is, the surplus output applied to the charging of the battery 50 can be set to a low output, overcharge can be prevented.

  Note that Pemed does not necessarily need to be pinpointed, and the operating point may be changed between when one cylinder is stopped and when two cylinders are stopped or when all cylinders are operated as long as the required driving force and exhaust purification requirements are satisfied. .

  FIG. 13 shows engine control, exhaust air-fuel ratio control, cylinder control, and MG drive for NOx regeneration (rich combustion control, λ ≦ 0.8) of the exhaust purification device 22 performed in the above-described step 4000 (FIG. 9). It is a flowchart which shows the subroutine for determining the target value of control.

  In the NOx regeneration target value determination routine of FIG. 13, in step 4100, in accordance with a subroutine of FIG. 15 described later, a cylinder stop pattern common to NOx regeneration and catalyst activity improvement, engine operating cylinder output, and MG output or power generation output target The value (cylinder control pattern B) is determined, and the process proceeds to step 4400.

  In step 4400, predetermined data preset in correspondence with the rotational speed Ne and the output Pe ′ of the working cylinder is retrieved, and the main injection amount Qmain and the main injection timing ITmain for performing the main injection control of the working cylinder are obtained. And go to step 4500.

  In step 4500, a predetermined data set in advance corresponding to the rotational speed Ne and the working cylinder output Pe ′ is retrieved, and the post injection amount Qpost and the post injection timing for performing the post injection for the purpose of NOx regeneration. Determine ITpost and go to step 4600.

  In step 4600, in addition to exhaust control, an EGR target value (driving signal for the EGR valve 5) for NOx regeneration is obtained, and the process proceeds to step 4700.

  In step 4700, in addition to exhaust control, an intake throttle target value (drive signal for the intake throttle valve 7) for the purpose of NOx regeneration is obtained, and the process returns.

  As will be described later, the exhaust temperature flowing into the exhaust purification device is about 200 ° C. or more, particularly when the temperature rise for regeneration and the exhaust control are not performed and the cylinder stop control is not performed. When a cylinder control pattern B, which will be described later, determined in the NOx regeneration target value determination routine, is performed, the exhaust temperature flowing into the exhaust purification device is about 300 ° C. or higher. Accordingly, it is possible to reduce the enhancement of post injection, EGR, intake throttle, etc., which are determined for the above-described temperature rise assistance for NOx regeneration, and to reduce the deterioration of fuel consumption caused by NOx regeneration.

  FIG. 14 shows target values for engine control, exhaust air-fuel ratio control, cylinder control, and MG drive control for improving the catalyst activity (lean combustion control) of the exhaust purification device 22 performed in step 5000 (FIG. 9). It is a flowchart which shows the subroutine for determining.

  In the catalyst activity improvement target value determination routine of FIG. 14, in step 4100, according to the subroutine of FIG. 15 described later, the cylinder stop pattern common to NOx regeneration and catalyst activity improvement, the output of the engine operating cylinder, and the MG output or power generation output A target value (cylinder control pattern B) is determined, and the process proceeds to step 5100.

  In step 5100, predetermined data preset in correspondence with the rotational speed Ne and the output Pe ′ of the working cylinder is retrieved, and the main injection amount Qmain and the main fuel injection timing ITmain for performing the main injection control of the working cylinder. To step 5200.

  In step 5200, it is determined whether the exhaust temperature Tex is below a predetermined temperature Tex1 (for example, 250 ° C.) that provides sufficient catalytic activity. If yes, the process proceeds to step 5300, and if no, the process returns.

  In step 5300, predetermined data set in advance corresponding to the rotational speed Ne and the output Pe ′ of the working cylinder is retrieved, and the post injection amount Qpost and post injection for performing post injection for the purpose of improving the catalyst activity. Time ITpost is obtained and the process proceeds to step 5400.

  In step 5400, in addition to the exhaust control, an EGR target value (drive signal for the EGR valve 5) for the purpose of improving the catalyst activity is obtained, and the process proceeds to step 5500.

  In step 5500, in addition to exhaust control, an intake throttle target value (drive signal for the intake throttle valve 7) for the purpose of improving the catalyst activity is obtained, and a return is obtained.

  As in the case of NOx regeneration, by performing a cylinder control pattern B, which will be described later, determined in the catalyst activity improvement target value determination routine, the exhaust temperature flowing into the exhaust purification device is about 300 ° C. or higher. It is done. Therefore, it is desirable and usually only to implement post-injection, EGR, intake throttle, etc., which are determined to assist the temperature increase for improving the catalyst activity described above, only immediately after the engine is started. But it can be stopped very slightly.

  FIG. 15 is a flowchart showing a subroutine for determining a cylinder control pattern B common to NOx regeneration and catalyst activity improvement performed in step 4100 (FIGS. 13 and 14) described above.

  The cylinder control pattern B determination routine of FIG. 15 will be described with reference to the characteristic diagrams shown in FIGS. 2 to 6 as well, but the same parts as the cylinder control pattern A determination routine will be described briefly.

  In step 4110, it is determined whether or not the vehicle driving force Prun is greater than or equal to the set maximum output in the four-cylinder operation shown as Pe5 in FIGS.

  In step 4160, the output to be generated by each cylinder of engine 1 and MG2 · 53 is determined as follows. Then, in step 2300, the cylinder control pattern 0, that is, the four-cylinder operation is determined and a return is made.

Each cylinder output Pe ′ = Pemax → 4 × Pemax = Pe5
Motor output Pm = Prun-Pe5
If No in step 4110, the process proceeds to step 4120, and it is determined whether the vehicle driving force Prun is equal to or greater than the best fuel consumption setting output in the four-cylinder operation shown as Pe4 in FIGS. It is determined whether the remaining charge (SOC) of the battery 50 is higher than a predetermined value SOC1 at which power can be stably supplied. If Yes, the process proceeds to Step 4180. If No, the process proceeds to Step 4190. Proceed to

  In step 4180, each cylinder of engine 1 and the output to be generated by MG2 · 53 are determined as follows. In step 2300, cylinder control pattern 0 is determined.

Each cylinder output Pe ′ = Pemed → 4 × Pemed = Pe4
Motor output Pm = Prun-Pe4
In step 4190, the output to be generated by each cylinder of the engine 1 is determined as follows, and the surplus output of the engine 1 is applied to the power generation of the MG1 · 51 and MG2 · 53. In step 2300, the cylinder control pattern 0 is determined.

Each cylinder output Pe ′ = Pemax → 4 × Pemax = Pe5
Power generation output Pdiv = Pe5-Prun
If No in step 4120, the process proceeds to step 4130, where the vehicle driving force Prun is greater than or equal to the set output corresponding to the lower limit value of the fuel efficiency range F of FIG. 7 in the four-cylinder operation shown as Pe3 in FIGS. If YES, the process proceeds to step 4200, where it is determined whether the remaining charge (SOC) of the battery 50 is higher than the predetermined value SOC1, and if YES, the process proceeds to step 4210. Then go to step 4220.

  In step 4210, the output to be generated by each cylinder of engine 1 and MG2 · 53 is determined as follows. In step 2300, the cylinder control pattern 0 is determined.

Each cylinder output Pe ′ = Pemin → 4 × Pemin = Pe3
Motor output Pm = Prun-Pe3
In step 4220, the output to be generated by each cylinder of the engine 1 is determined as follows, and the surplus output of the engine 1 is applied to the power generation of the MG1 · 51 and MG2 · 53. In step 2300, the cylinder control pattern 0 is determined.

Each cylinder output Pe ′ = Pemed → 4 × Pemed = Pe4
Power generation output Pdiv = Pe4-Prun
Here, Pe3 corresponds to each cylinder output Pemin at an intermediate point between b and c, which is a point corresponding to the lower limit value of the fuel efficiency range F of FIG. 7, and normal temperature control and exhaust control for each regeneration are not performed. During operation, an exhaust temperature of about 300 ° C. is obtained.

  If NO in step 4130, the process proceeds to step 4140, and the vehicle driving force Prun exceeds the set output corresponding to the aforementioned Pemin when the one-cylinder stop (three-cylinder) operation shown as Pe2 in FIGS. If yes, the process proceeds to step 4230, where it is determined whether the remaining charge (SOC) of the battery 50 is higher than the predetermined value SOC1, and if yes, the process proceeds to step 4240, and No. If so, go to Step 4250.

  In step 4240, the output to be generated by each cylinder of engine 1 and MG2 · 53 is determined as follows. In step 2400, the cylinder control pattern 1, that is, the one-cylinder stop (three-cylinder) operation is determined and the process returns.

Each cylinder output Pe ′ = Pemin → 3 × Pemin = Pe2
Motor output Pm = Prun-Pe2
In step 4250, the output to be generated by each cylinder of the engine 1 is determined as follows, and the surplus output of the engine 1 is applied to the power generation of the MG1 · 51 and MG2 · 53. In step 2300, the cylinder control pattern 0 is determined.

Each cylinder output Pe ′ = Pemin → 4 × Pemin = Pe3
Power generation output Pdiv = Pe3-Prun
If NO in step 4140, the process proceeds to step 4150, where the vehicle driving force Prun exceeds the set output corresponding to the aforementioned Pemin when the two-cylinder stop (two-cylinder) operation shown as Pe1 in FIGS. If YES in step 4260, the flow advances to step 4260 to determine whether the remaining charge (SOC) of the battery 50 is higher than the predetermined value SOC1. If YES in step 4260, the flow advances to step 4270. If yes, go to Step 4280.

  In step 4270, the output to be generated by each cylinder of engine 1 and MG2 · 53 is determined as follows. In step 2500, the cylinder control pattern 2, that is, the two-cylinder stop (two-cylinder) operation is determined and the process returns.

Each cylinder output Pe ′ = Pemin → 2 × Pemin = Pe1
Motor output Pm = Prun-Pe1
In step 4280, the output to be generated by each cylinder of the engine 1 is determined as follows, and the surplus output of the engine 1 is applied to the power generation of the MG1 · 51 and MG2 · 53. In step 2400, the cylinder control pattern 1 is determined.

Each cylinder output Pe ′ = Pemin → 3 × Pemin = Pe2
Power generation output Pdiv = Pe2-Prun
If NO in step 4150, the process proceeds to step 4290 to determine whether the remaining charge (SOC) of the battery 50 is higher than the predetermined value SOC1, and if YES, the process proceeds to step 4300, and if NO The process proceeds to step 4310. In step 4300, it is determined whether NOx regeneration is in progress. If yes, the process proceeds to step 4310, and if no, the process proceeds to step 4320.

  In step S4310, the output to be generated by each cylinder of the engine 1 is determined as follows, and the surplus output of the engine 1 is used for power generation of the MG1 · 51 and MG2 · 53. In step 2500, the cylinder control pattern 2 is determined.

Each cylinder output Pe ′ = Pemin → 2 × Pemin = Pe1
Power generation output Pdiv = Pe1-Prun
In step 4320, the output to be generated by MG2 · 53 is determined as follows, and the process returns.

Motor output Pm = Prun
As described above, the minimum value of the vehicle driving force Prun in the cylinder control pattern B is set to Pe1. When the required driving force Prun is equal to or less than Pe1, if the remaining charge of the battery 50 exceeds a predetermined value SOC1 at which stable power can be supplied and if NOx regeneration is not being performed, motor driving operation is performed (step 4320).

  Further, the surplus output (Pdiv = Pe1-Prun) is applied to the charging of the battery 50 until the remaining charge of the battery 50 is SOC1 or less, or during NOx regeneration and the NOx regeneration is completed (step 4310). . Note that Pe1 corresponds to the above-described Pemin when the two-cylinder stop (two-cylinder) operation is performed, but when the four-cylinder operation is performed, the catalytic activity assisting region falls below the point b in FIG. This corresponds to the upper limit point of A (the region where the temperature rise assist is necessary to obtain sufficient catalytic activity since the temperature of the exhaust gas flowing into the exhaust purification device is approximately 200 ° C. or lower).

  On the other hand, by performing cylinder stop control, the exhaust temperature flowing into the exhaust purification device can be about 300 ° C. or higher. Therefore, at the time of NOx regeneration, it is possible to reduce the enhancement of post injection, EGR, intake throttle, and the like determined for temperature increase assistance and exhaust control. Further, when the catalyst activity is improved, the enhancements such as post injection, EGR, intake throttle, etc., which are determined to assist in raising the temperature, can be minimized. In addition, each cylinder output that obtains Pe3, Pe2, and Pe1 is based on the Pemin of the output point corresponding to the lower limit value of the fuel efficiency range F, so that the deterioration in fuel efficiency caused by performing the NOx regeneration or the catalyst activity improving process is minimized. It can be stopped to the limit.

  In addition, since the minimum value of the vehicle driving force Prun until the end of NOx regeneration can be set to a low output, that is, the surplus output applied to the charging of the battery 50 can be set to a low output, overcharge can be prevented similarly to the cylinder control pattern A. it can.

  Note that Pemin does not necessarily need to be pinpointed, and the operating point may be changed between when one cylinder is stopped and when two cylinders are stopped or when all cylinders are operated as long as the required driving force and exhaust purification requirements are satisfied. .

  FIG. 16 is a flowchart showing a subroutine for engine start control in step 800 (FIG. 8).

  In the engine start control routine of FIG. 16, in step 810, energization control of the glow plug 24 is performed, and the process proceeds to step 820.

  Here, the energization control of the glow plug 24 stops the energization if the temperature is sufficient to ignite the injected fuel on the basis of the temperature of the glow plug 24 that can be obtained by the energization current, for example, and is insufficient for ignition. If the temperature is low, control such as energization may be performed.

  In step 820, it is determined whether or not the remaining charge (SOC) of the battery 50 is higher than a predetermined value SOC1 at which power can be stably supplied. If Yes, the process proceeds to step 830. Proceeding to 870, the EHC 21 is deenergized to prevent overdischarge of the battery 50, and the process proceeds to step 850.

  In step 830, energization control of the EHC 21 is performed, and the process proceeds to step 840.

  Here, the energization control of the EHC 21 is performed, for example, at a temperature at which the exhaust temperature (EHC temperature when the engine is stopped) Tex detected based on a signal from the temperature sensor 35 exceeds a predetermined temperature Tex1 (for example, 250 ° C.) at which the catalyst is sufficiently activated. If it exists, the energization is stopped, and if the temperature is lower, the energization may be performed.

  In step 840, it is determined whether the EHC 21 has reached a predetermined heating stage (determined based on the EHC temperature or the exhaust temperature Tex). If yes, the process proceeds to step 850. If No, it is a return.

  In Step 850, it is determined whether or not the glow plug 24 has reached a predetermined heating stage (determined by the glow plug temperature or the like).

  If Yes in step 850, that is, if both the EHC 21 and the glow plug 24 have reached a predetermined heating stage, the routine proceeds to step 860, where the engine 1 is started.

  In this starting operation, for example, first, motoring of the engine 1 is started by MG1 · 51. Next, when the motoring rotational speed of the engine 1 reaches a predetermined stable level, the pressure control valve 13 and the fuel injection valve 15 of the supply pump 11 are driven, and fuel suitable for starting is supplied to reach a complete explosion. Perform the operation.

  FIG. 17 is a flowchart showing a subroutine for engine operation control performed in the aforementioned step 900 (FIG. 8). The vehicle driving force (Prun) or engine determined in the aforementioned steps 200 and 400 (FIG. 8) is shown. For the purpose of output control of the engine 1 to obtain a shared output (Pe), S poison regeneration, PM regeneration, NOx regeneration, and catalytic activity improvement, the number of operating (stopped) cylinders of the engine and the load (output) of the working cylinders are set. This includes cylinder control that is determined and controlled, and control of the exhaust air-fuel ratio that is discharged from the working cylinder (flows into the exhaust purification catalyst).

  In the engine operation control routine of FIG. 17, in step 830, the above-described energization control of the EHC 21 is performed, and the process proceeds to step 910.

  In step 910, the pressure control of the common rail 14 and the drive control of the fuel injection valve 15 are performed based on the determined working cylinder and the target values of the main injection and the post injection, and the process proceeds to step 920.

  In step 920, the EGR valve 5 is controlled to open and close based on the determined EGR target value, and the process proceeds to step 930.

  In step 930, the intake throttle valve 7 is controlled to open and close based on the determined intake throttle target value, and the process proceeds to step 940.

  In step 940, the intake cutoff valve 6 is controlled to open and close based on the determined target values of the stopped cylinder and the operating cylinder, and the process returns.

  FIG. 18 is a flowchart showing a subroutine for engine stop control performed in the above-described step 1000 (FIG. 8) when the engine 1 does not need to be operated.

  In the engine stop control routine of FIG. 18, in step 1010, energization of the EHC 21 is stopped and the process proceeds to step 1020.

  In step 1020, the fuel injection valve 15 is stopped and the process proceeds to step 1030.

  In Step 1030, the EGR valve 5 is closed and the process proceeds to Step 1040.

  In step 1040, the intake throttle valve 7 is opened and the routine proceeds to step 1050.

  In step 1050, the intake shutoff valve 6 is opened and the process returns.

  As described above, according to the present invention, in the hybrid vehicle, the required driving force calculating means for calculating the driving force (Prun) necessary for traveling of the vehicle and the remaining charge (SOC) of the battery 50 are detected. A remaining charge detection means, an operation necessity determination means for determining whether or not the engine needs to be operated based on the required driving force (Prun) and the remaining charge (SOC), and an exhaust passage 3 of the engine 1 Exhaust purification device (especially an exhaust purification device configured to include DPF, LNT, and oxidation catalyst) 22 and an exhaust temperature or exhaust air-fuel ratio requirement based on the state of the exhaust purification device 22 (especially a catalyst) An exhaust purification device request detecting means for detecting an activity improvement request, a NOx regeneration request, a PM regeneration request, and an S poisoning regeneration request), and a gas in each cylinder of the engine. By stopping the inflow and outflow of fuel and the fuel supply, some cylinders can be stopped, and when the engine is required to be operated by the operation necessity determining means and the engine is operated, the exhaust The number of stop cylinders and the output of the working cylinder are determined according to the exhaust temperature or exhaust air / fuel ratio request based on the state of the purification device 22, the required driving force (Prun), and the remaining charge (SOC). And an exhaust air-fuel ratio control means for controlling the exhaust air-fuel ratio that is discharged from the working cylinder of the engine and flows into the exhaust purification device 22 to constitute the exhaust purification control device. As a result, overcharging and overdischarging of the battery 50 can be prevented when performing various processes for the purpose of charging the battery 50 or improving or recovering the exhaust purification performance of the exhaust purification device 22. Further, at that time, an excessive temperature rise of the exhaust purification device 22 does not occur, and the exhaust purification performance is not impaired. In addition, the energy consumed for various processing controls, that is, the loss of fuel consumption can be minimized.

  The operation necessity determination means is configured to operate the engine when the remaining charge amount exceeds a predetermined remaining amount (SOC1) and the required driving force is lower than a predetermined driving force (Pe1). When it is determined unnecessary, the engine is stopped and the remaining charge amount is lower than a predetermined remaining amount (SOC1), or when the required driving force is higher than a predetermined predetermined driving force (Pe1), It is determined that the engine needs to be operated and the engine is operated. During such operation, cylinder control is performed according to the state of the exhaust purification device, the required driving force, and the remaining charge.

  The cylinder control means determines the output of each working cylinder so that the sum of the outputs of each working cylinder during the cylinder stop operation is equal to the sum of the outputs of each cylinder during the all cylinder operation. The number of stopped cylinders is determined so that the output of each of the working cylinders does not exceed a predetermined value (Pemin, Pemed).

  More specifically, the number of stopped cylinders is determined so that the output of each working cylinder at the time of cylinder stop operation becomes a predetermined value (Pemin, Pemed), and the shortage of output is compensated by motor assist, The surplus will be generated.

  Here, as shown in FIG. 19 and FIG. 20, the predetermined value is changed depending on whether it is a catalyst activity improvement request, a NOx regeneration request, a PM regeneration request, or an S poison regeneration request, thereby improving the catalyst activity. It is set to the low load side at the time of request or NOx regeneration request (Pemin), whereas it is set to the high load side at the time of PM regeneration request or S poisoning regeneration request (Pemed). Thereby, it can drive | operate in the area | region suitable for each request | requirement.

  The exhaust air-fuel ratio control means keeps the exhaust air-fuel ratio of the working cylinder lean when the catalyst activity improvement request is made. When NOx regeneration is requested, the exhaust air-fuel ratio of the working cylinder is enriched. When PM regeneration is requested, the exhaust air-fuel ratio of the working cylinder is kept lean. When the S poisoning regeneration request is made, the exhaust air-fuel ratio of the working cylinder is controlled to be stoichiometric or rich.

  Further, the cylinder control means stops all the cylinders in a deceleration state (engine brake state) except when NOx regeneration request, PM regeneration request, and S poisoning regeneration request are made. That is, the engine is determined to be required to be operated by the operation necessity determination means, and the cylinder is controlled (cylinder stop control) and the exhaust according to the state of the exhaust gas purification device, the required driving force, and the remaining charge amount. When air-fuel ratio control is performed, when the vehicle shifts to a deceleration state (engine brake state), all the cylinders are stopped when the catalyst activity is being improved (FIG. 8). However, when the regeneration process is being performed, that is, when the NOx regeneration, the PM regeneration, or the S poisoning regeneration is being performed, these processes are continued until the process for a predetermined time is completed.

  Further, the exhaust air / fuel ratio control means has at least one of post injection, intake throttle strengthening, and EGR strengthening performed in an expansion stroke or an exhaust stroke after the main injection of fuel for generating a drive output to the working cylinder. By selecting one of them, the air-fuel ratio of the exhaust gas discharged from the working cylinder of the internal combustion engine and flowing into the exhaust gas purification device is controlled.

The system block diagram which shows one Embodiment of the exhaust gas purification control apparatus of this invention Cylinder stop control characteristic chart for improving catalyst activity Cylinder stop control characteristic chart for NOx regeneration Cylinder stop control characteristic chart for catalyst activity improvement and NOx regeneration when charging is insufficient Cylinder stop control characteristic diagram for PM regeneration and S poison regeneration Cylinder stop control characteristic diagram for PM regeneration and S poison regeneration when charging is insufficient Diesel engine operating area characteristics chart Flow chart of basic control routine of hybrid system Flow chart of drive pattern determination routine Flow chart of S poisoning regeneration target value determination routine Flow chart of PM regeneration target value determination routine Cylinder control pattern A determination routine flowchart Flow chart of NOx regeneration target value determination routine Flow chart of catalyst activity improvement target value determination routine Flowchart of cylinder control pattern B determination routine Flow chart of engine start control routine Flow chart of engine operation control routine Flow chart showing engine stop control routine Cylinder stop pattern for catalyst activity improvement and NOx regeneration Cylinder stop pattern for PM regeneration and S poison regeneration

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Diesel engine 2 Intake passage 2a Air cleaner 2b Supercharger compressor 2c Intercooler 2d Intake pipe 3 Exhaust passage 3a Turbocharger turbine 4 EGR passage 5 EGR valve 6 Intake shut-off valve 7 Intake throttle valve 10 Fuel injection device 11 Supply pump 12 Fuel supply passage 13 Pressure control valve 14 Common rail (accumulation chamber)
15 Fuel injection valve 16 Fuel supply passage 17 Overflow passage 18 One-way valve 19 Fuel return passage 20 Exhaust purification post-treatment device 21 EHC
22 Exhaust gas purification device (DPF + LNT + oxidation catalyst)
24 Glow plug 30 Engine control unit 31 Water temperature sensor 32 Crank angle sensor 33 Cam angle sensor 34 Pressure sensor 35 Temperature sensor 36 Oxygen concentration sensor 40 Hybrid control unit 41 Accelerator sensor 42 Start key 43 Shift lever position sensor 44 Brake operation switch 45 Vehicle speed sensor 46 Battery remaining amount sensor 50 Battery 51 Motor generator (MG1)
52 Power transmission mechanism (CVT)
53 Motor generator (MG2)
54 Differential gear 55a, 55b Drive wheel 60 Fuel tank

Claims (13)

An internal combustion engine, a motor generator that also serves as a generator, and a battery that can supply power to the motor generator and charge the generated power of the motor generator. The output of at least one of the internal combustion engine and the motor generator In a hybrid vehicle that drives a vehicle by generating a driving force,
A required driving force calculating means for calculating a driving force required for traveling of the vehicle;
Remaining charge detection means for detecting the remaining charge of the battery;
Driving necessity determination means for determining whether or not the internal combustion engine needs to be operated based on the required driving force and the remaining charge amount;
An exhaust purification device disposed in an exhaust passage of the internal combustion engine;
An exhaust purification device request detecting means for detecting a request for an exhaust temperature or an exhaust air-fuel ratio based on a state of the exhaust purification device;
By stopping the inflow and outflow of gas and the fuel supply in each cylinder of the internal combustion engine, some cylinders can be stopped, and the internal combustion engine is determined to be required to be operated by the operation necessity determining means. When the engine is operated, the number of stop cylinders and the output of the working cylinders according to the request for the exhaust temperature or the exhaust air-fuel ratio based on the state of the exhaust purification device, the required driving force, and the remaining charge Cylinder control means for determining and controlling,
Exhaust air-fuel ratio control means for controlling the exhaust air-fuel ratio discharged from the working cylinder of the internal combustion engine and flowing into the exhaust purification device;
An exhaust gas purification control apparatus for an internal combustion engine in a hybrid vehicle.   The operation necessity determination means determines that the operation of the internal combustion engine is unnecessary when the remaining charge amount exceeds a predetermined predetermined remaining amount and the required driving force is lower than a predetermined predetermined driving force. The internal combustion engine is stopped and the internal combustion engine is determined to be required to operate when the remaining charge amount is less than a predetermined predetermined remaining amount or when the required driving force exceeds a predetermined predetermined driving force. The exhaust gas purification control apparatus for an internal combustion engine in a hybrid vehicle according to claim 1, wherein the internal combustion engine is operated.   The exhaust purification device is a filter that collects PM in exhaust gas, adsorbs NOx in exhaust gas when the exhaust air-fuel ratio is lean, and NOx that desorbs and reduces adsorbed NOx when the exhaust air-fuel ratio is rich. The exhaust purification control device for an internal combustion engine in a hybrid vehicle according to claim 1 or 2, comprising a trap catalyst and an oxidation catalyst for oxidizing HC and CO in the exhaust.   The exhaust purification device request detection means includes a catalyst activity improvement request that needs to increase the exhaust gas temperature to improve the catalyst activity, and a NOx regeneration request that needs to desorb and purify NOx adsorbed on the NOx trap catalyst. At least one of the PM regeneration request that needs to burn and remove PM collected by the PM trapping filter and the S poison regeneration request that needs to burn and remove S poisoned by the NOx trap catalyst The exhaust gas purification control apparatus for an internal combustion engine in a hybrid vehicle according to claim 3, wherein:   The cylinder control means determines the output of each working cylinder so that a sum of outputs of each working cylinder during cylinder stop operation is equal to a sum of outputs of each cylinder during all cylinder operation. Item 6. An exhaust gas purification control apparatus for an internal combustion engine in a hybrid vehicle according to Item 4.   6. The internal combustion engine in a hybrid vehicle according to claim 5, wherein the cylinder control means determines the number of stopped cylinders so that the output of each working cylinder during cylinder stop operation does not exceed a predetermined value. Exhaust purification control device.   The predetermined value is changed depending on whether it is a catalyst activity improvement request, a NOx regeneration request, a PM regeneration request, or an S poison regeneration request, and is set to a low load side when a catalyst activity improvement request or a NOx regeneration request is made. On the other hand, the exhaust gas purification control apparatus for an internal combustion engine in a hybrid vehicle according to claim 6, wherein the exhaust gas purification control device is set to a high load side at the time of PM regeneration request or S poisoning regeneration request.   The internal combustion engine in a hybrid vehicle according to any one of claims 4 to 7, wherein the exhaust air / fuel ratio control means holds the exhaust air / fuel ratio of the working cylinder lean when a catalyst activity improvement request is made. Exhaust purification control device.   The exhaust gas of the internal combustion engine in the hybrid vehicle according to any one of claims 4 to 8, wherein the exhaust air / fuel ratio control means enriches the exhaust air / fuel ratio of the working cylinder when NOx regeneration is requested. Purification control device.   The internal combustion engine of the hybrid vehicle according to any one of claims 4 to 9, wherein the exhaust air / fuel ratio control means keeps the exhaust air / fuel ratio of the working cylinder lean when PM regeneration is requested. Exhaust gas purification control device.   The hybrid vehicle according to any one of claims 4 to 10, wherein the exhaust air / fuel ratio control means controls the exhaust air / fuel ratio of the working cylinder to be stoichiometric or rich when an S poisoning regeneration request is made. An exhaust purification control apparatus for an internal combustion engine in   5. The cylinder control unit according to claim 4, wherein the cylinder control unit stops all cylinders when the engine is in a decelerating state except when NOx regeneration is requested, when PM regeneration is requested, and when S poison regeneration is requested. Item 12. The exhaust gas purification control device for an internal combustion engine in the hybrid vehicle according to any one of Items 11 to 11.   The exhaust air-fuel ratio control means performs at least one of post-injection, intake throttle strengthening, and EGR strengthening performed in an expansion stroke or an exhaust stroke after the main injection of fuel for generating a drive output for the working cylinder. The air-fuel ratio of the exhaust gas discharged from the working cylinder of the internal combustion engine and flowing into the exhaust gas purification device is controlled by being selected and executed, according to any one of claims 1 to 12. An exhaust purification control device for an internal combustion engine in a hybrid vehicle.

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