JP2008230443A - Control device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device of an internal combustion engine capable of shortening S poisoning regeneration control time by early heating a catalyst. <P>SOLUTION: The control device of an internal combustion engine controls a hybrid vehicle that can distribute outputs from the internal combustion engine and an electric motor to driving force of a vehicle and charging and discharging of a battery. Specifically, in executing the S poisoning regeneration control to regenerate sulfur poisoning of a catalyst, the control device of an internal combustion engine controls output of the internal combustion engine so as to exceed a required output in the case that the required output of the internal combustion engine becomes a prescribed value or above. Thus, the catalyst can be heated earlier and the S poisoning regeneration control time can be shortened. Further, fuel consumption can be secured because a battery can be charged in controlling the S poisoning regeneration. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device for an internal combustion engine that is applied to a hybrid vehicle and performs control for recovering a catalyst provided in an exhaust passage.

  Conventionally, in order to recover sulfur (S) poisoning of the catalyst provided in the exhaust passage, S poisoning regeneration control has been executed so that the temperature of the catalyst is raised. For example, Patent Document 1 describes a technique for maintaining an engine output at a predetermined value or higher during S poisoning regeneration control in a hybrid vehicle. Patent Document 2 describes a technique for regenerating an increase in engine output during S poisoning regeneration control using a motor included in a hybrid vehicle.

JP 2004-278465 A JP 2001-241341 A

  However, with the techniques described in Patent Documents 1 and 2 described above, the temperature of the catalyst may decrease when the engine is under a low load or when it temporarily deviates from the execution condition of the S poisoning regeneration control. there were. For this reason, the S poisoning regeneration control may take time.

  The present invention has been made to solve the above-described problems, and provides an internal combustion engine control device capable of shortening the S-poisoning regeneration control time by raising the temperature of the catalyst early. The purpose is to do.

  In one aspect of the present invention, an internal combustion engine control device that controls a hybrid vehicle that can distribute outputs from an internal combustion engine and an electric motor to vehicle driving force and battery charge / discharge is provided in an exhaust passage. When the required output in the internal combustion engine exceeds a predetermined value during execution of the S poison regeneration control for recovering sulfur poisoning in the provided catalyst, the output of the internal combustion engine is set to be higher than the required output. Output control means for performing control to increase is provided.

  The control device for the internal combustion engine is preferably used for controlling a hybrid vehicle that can distribute the output from each of the internal combustion engine and the electric motor to the driving force of the vehicle and the charge / discharge of the battery. Specifically, the control device for the internal combustion engine executes S poisoning regeneration control so that the temperature of the catalyst is raised in order to recover sulfur (S) poisoning of the catalyst provided in the exhaust passage. In this case, the output control means performs control to increase the output of the internal combustion engine beyond the required output when the required output in the internal combustion engine becomes equal to or greater than a predetermined value during the execution of the S poisoning regeneration control. According to the control device for an internal combustion engine described above, in the region where the required output is equal to or greater than a predetermined value, the output of the internal combustion engine is increased and the S poisoning regeneration control is executed, so that the catalyst can be raised in temperature early. . Therefore, it is possible to shorten the S poisoning regeneration control time. In addition, during S poisoning regeneration control, the battery can be charged by regenerating output corresponding to the difference between the output of the internal combustion engine and the required output by the generator, so that fuel consumption can be ensured. .

  In one aspect of the control apparatus for an internal combustion engine, the output control means is configured to perform a predetermined time when the required output becomes less than the predetermined value during execution of the S poisoning regeneration control. The output is maintained higher than the required output.

  In this aspect, the output control means temporarily deviates from the execution condition of the S poisoning regeneration control when there is a short-term decrease in the required output during the S poisoning regeneration control, that is, during the S poisoning regeneration control. If this happens, the control to increase the output of the internal combustion engine above the required output is continued. Thereby, since the fall of catalyst temperature can be suppressed effectively, it becomes possible to shorten S poisoning reproduction | regeneration control time effectively.

  In another aspect of the control device for an internal combustion engine, when the S poisoning regeneration control is executed, the operation of the internal combustion engine is stopped rather than operating the internal combustion engine and flowing exhaust gas through the catalyst. When the required output is such that the temperature of the catalyst does not decrease, stop control means for stopping the operation of the internal combustion engine is further provided.

  In this aspect, the stop control means stops the operation of the internal combustion engine when the load of the internal combustion engine is in a considerably low region during the S poisoning regeneration control. Thereby, it can suppress that the exhaust gas from which temperature fell is supplied to a catalyst, and can suppress the fall of catalyst temperature appropriately.

  Preferably, in the control device for an internal combustion engine, the predetermined value can be set based on an output of the internal combustion engine necessary for raising the temperature of the catalyst and an output that can be regenerated by a generator. .

  Preferably, the output control means performs control to increase the output of the internal combustion engine above the required output when the charge amount of the battery is equal to or lower than a predetermined value and the temperature of the catalyst is lower than a predetermined temperature. Can do.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

[Vehicle configuration]
First, a hybrid vehicle to which the control device for an internal combustion engine according to the present embodiment is applied will be described with reference to FIG.

  FIG. 1 is a diagram illustrating a schematic configuration of the hybrid vehicle 10. The hybrid vehicle 10 mainly includes an axle 110, wheels 120, an ECU (Electronic Control Unit) 100, an engine (internal combustion engine) 200, motors MG1, MG2, a planetary gear 300, an inverter 400, and a battery 500. , An SOC (State Of Charge) sensor 600 and an accelerator opening sensor 700 are provided. The hybrid vehicle 10 is configured as a so-called series / parallel hybrid vehicle.

  The axle 110 is a part of a power transmission system that transmits the power of the engine 200 and the motor MG2 to the wheels 120. The wheels 120 are wheels of the hybrid vehicle 10, and only the left and right front wheels are particularly shown in FIG. 1 for simplification of description. The engine 200 is configured by a gasoline engine or the like, and functions as a main power source of the hybrid vehicle 10. The detailed configuration of engine 200 will be described later.

  The motor MG1 is configured to function mainly as a generator for charging the battery 500 or a generator for supplying electric power to the motor MG2. Motor MG2 is configured to function mainly as an electric motor that assists the output of engine 200. These motors MG1 and MG2 are configured as, for example, synchronous motor generators, and include a rotor having a plurality of permanent magnets on the outer peripheral surface, and a stator wound with a three-phase coil that forms a rotating magnetic field. Planetary gear (planetary gear mechanism) 300 is configured to be able to distribute the output of engine 200 to motor MG1 and axle 110, and functions as a power split mechanism.

  Inverter 400 is a DC / AC converter that controls input / output of electric power between battery 500 and motors MG1 and MG2. For example, the inverter 400 converts the DC power extracted from the battery 500 into AC power, or supplies AC power generated by the motor MG1 to the motor MG2, and converts the AC power generated by the motor MG1 into DC power. It can be converted to and supplied to the battery 500.

  The battery 500 is a rechargeable storage battery configured to be able to function as a power source for driving the motor MG1 and the motor MG2. The SOC sensor 600 is a sensor configured to be able to detect the charge state / charge amount of the battery 500 (hereinafter simply referred to as “SOC”). The SOC sensor 600 is electrically connected to the ECU 100, and the SOC of the battery 500 is always grasped by the ECU 100.

  The accelerator opening sensor 700 is a sensor configured to detect the amount of depression of the accelerator pedal (accelerator opening) by the driver. A detection signal corresponding to the accelerator opening detected by the accelerator opening sensor 700 is supplied to the ECU 100.

  The ECU 100 is an electronic control unit that includes an unshown CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory), and controls the entire operation of the hybrid vehicle 10. In the present embodiment, the ECU 100 performs output from the engine 200, charging of the battery 500 (regeneration by the motor MG1), and discharging of the battery 500 based on a request output from the driver or a request for S poisoning regeneration control described later. (Assist using the output of the motor MG2) is controlled. That is, ECU 100 performs control to distribute the output from each of engine 200 and motor MG2 to the driving force of the vehicle and the charging / discharging of the battery.

[Engine configuration]
Next, a specific configuration of the engine 200 described above will be described with reference to FIG.

  FIG. 2 is a diagram illustrating a schematic configuration of the engine 200. In FIG. 2, solid arrows indicate gas flows, and broken arrows indicate signal input / output. Moreover, the thick line in FIG. 2 has shown the channel | path (piping) through which gas passes.

  The engine 200 is configured as a V-type 6-cylinder engine in which three banks (cylinders) 8La and 8Ra are provided in each of the left and right banks (cylinder groups) 8L and 8R. The engine 200 is a device that generates power by burning a mixture of air and fuel supplied via an intake passage 3 and an intake manifold (not shown). The engine 200 is controlled by the control signals S8L and S8R supplied from the ECU 100, such as the fuel injection amount and the injection timing.

  An intercooler (IC) 5 and a throttle valve 6 are provided in the intake passage 3 for guiding intake air to the cylinders 8La and 8Ra. The intercooler 5 is a device that cools the intake air. The throttle valve 6 is controlled in throttle opening based on a control signal S 6 from the ECU 100, and controls the flow rate of intake air flowing through the intake passage 3. Further, in the intake passage 3, a compressor 4La of the turbocharger 4L and a compressor 4Ra of the turbocharger 4R are disposed.

  Further, exhaust passages 11L and 11R are connected to the banks 8L and 8R, respectively. A turbine 4Lb of the turbocharger 4L is disposed in the exhaust passage 11L, and a turbine 4Rb of the turbocharger 4R is disposed in the exhaust passage 11R. The exhaust passage 11L is provided with a start catalyst 12L, and the exhaust passage 11R is provided with a start catalyst 12R. For example, a three-way catalyst or the like can be used as the start catalysts 12L and 12R.

  Further, the exhaust passage 11L and the exhaust passage 11R join downstream of the start catalysts 12L and 12R. An underfloor catalyst (hereinafter referred to as “U / F catalyst”) 16 is provided in the exhaust passage 11 on the downstream side of the joined portion. For example, as the U / F catalyst 16, a NOx catalyst that can purify NOx can be used. Further, the U / F catalyst 16 is provided with a temperature sensor 17 configured to detect the temperature. The temperature sensor 17 detects the temperature of the U / F catalyst 16 (hereinafter simply referred to as “catalyst temperature”), and supplies a detection signal S17 corresponding to the detected catalyst temperature to the ECU 100.

  The ECU 100 mainly executes S poisoning regeneration control so that the temperature of the catalyst is raised in order to recover the sulfur (S) poisoning of the U / F catalyst 16. Specifically, the ECU 100 performs control so that the engine 200 outputs more than the required output during the S poison regeneration control (hereinafter, such control is referred to as “S poison regeneration regeneration temperature increase control”). Also called bank control. Here, the bank control means that one of the banks 8L and 8R is lean burned and the other is richly burned, so that the air-fuel ratio of the exhaust gas supplied to the U / F catalyst 16 is stoichiometric and the U / F catalyst 16 It is control for making it react with. By executing the S poisoning regeneration control as described above, the temperature of the U / F catalyst 16 is raised, and the S poisoning in the U / F catalyst 16 is recovered. Hereinafter, the bank control is also referred to as “S poisoning regeneration A / F control”.

  As described above, the ECU 100 functions as a control device for an internal combustion engine in the present invention. Specifically, the ECU 100 functions as output control means and stop control means in the present invention.

  In the above, the embodiment has been described in which the ECU 100 executes both the control on the engine 200 and the control on the motors MG1, MG2, and the battery 500. However, the present invention is not limited to this. In another example, when there are separate ECUs that control the engine 200 and ECUs that control the motors MG1, MG2, and the battery 500, these ECUs cooperate to perform the control described above. Can be executed.

  Below, the S poisoning reproduction | regeneration control method which concerns on embodiment of this invention is demonstrated.

[First Embodiment]
In the first embodiment, when the S-poisoning regeneration control is executed, the output of the engine 200 is output when the required output in the engine 200 is equal to or greater than a predetermined value (hereinafter referred to as “S-poisoning regeneration permission output”). Is controlled to be higher than the required output (S poisoning regeneration temperature increase control), and the battery 500 is charged by being regenerated by the motor MG1. The reason why the S poisoning regeneration temperature increase control is executed during the execution of the S poisoning regeneration control is to shorten the S poisoning regeneration control time by raising the temperature of the U / F catalyst 16 early.

  Here, the reason why the S poisoning regeneration temperature increase control is executed when the requested output is equal to or higher than the S poisoning regeneration permission output is as follows. The combined output of the requested output and the output regenerated by the motor MG1 generally corresponds to the output of the engine 200, but the output that can be regenerated by the motor MG1 (that is, the output that can be regenerated to the maximum by the motor MG1) is generally determined. Therefore, if the required output is not equal to or higher than a certain output (this output corresponds to the S poisoning regeneration permission output), the output of the engine 200 is necessary for effectively raising the temperature of the U / F catalyst 16. The output may not be reached. In other words, when the output required for effectively raising the temperature of the U / F catalyst 16 is output from the engine 200 when the required output is less than the S poisoning regeneration permission output, the output of the engine 200 is output. Even if the motor MG1 absorbs the maximum amount, the vehicle may generate an output that exceeds the required output. Therefore, in the present embodiment, control is performed to increase the output of the engine 200 above the requested output only when the requested output is equal to or greater than the S poisoning regeneration permission output. Note that the S poisoning regeneration permission output used for the determination with respect to the requested output is set based on the output of the engine 200 necessary for raising the temperature of the U / F catalyst 16 and the output that can be regenerated by the motor MG1.

  Next, with reference to FIG. 3, the S poisoning reproduction | regeneration control method which concerns on 1st Embodiment is demonstrated concretely. In the graph shown in FIG. 3, time is shown on the horizontal axis. Specifically, FIG. 3A shows on / off of an S poisoning regeneration flag that is set when there is a request for S poisoning regeneration control, FIG. 3B shows a load factor, and FIG. (C) shows the rotation speed of the engine 200, and FIG. 3 (d) shows the vehicle speed. 3 (e) shows the output of the engine 200, etc. FIG. 3 (f) shows the SOC of the battery 500, and FIG. 3 (g) shows the catalyst temperature of the U / F catalyst 16. Specifically, in FIG. 3E, the solid line P1 indicates the output of the engine 200, the alternate long and short dash line P2 indicates the drive wheel output, and the broken line indicates the S poisoning regeneration permission output.

  In this case, the requested output of the engine 200 becomes equal to or higher than the S poisoning regeneration permission output at time t10 while the S poisoning regeneration flag is on. Therefore, as indicated by the solid line P1 in FIG. 3, the ECU 100 executes control (S poisoning regeneration temperature increase control) that increases the output of the engine 200 from the required output at time t10. Specifically, the ECU 100 increases the load / rotation speed (see FIGS. 3B and 3C). Thereby, as shown in FIG.3 (g), after time t10, a catalyst temperature rises significantly. Furthermore, when the ECU 100 executes the control to increase the output of the engine 200 as described above, the motor MG1 regenerates an output corresponding to the difference between the output of the engine 200 and the requested output, and charges the battery 500. . Thereby, as shown in FIG.3 (f), SOC of the battery 500 rises after the time t10.

  Next, with reference to FIG. 4, the S poisoning regeneration control process according to the first embodiment will be described. FIG. 4 is a flowchart showing the S poisoning regeneration control process according to the first embodiment. This process is repeatedly executed by the ECU 100.

  First, in step S101, the ECU 100 determines whether or not there is an S poisoning regeneration control request. Here, the ECU 100 determines whether or not the S poisoning regeneration control is to be performed. In one example, the ECU 100 determines whether the sulfur poisoning regeneration control should be performed by estimating the amount of sulfur (S) in the U / F catalyst 16. In this case, the ECU 100 estimates the amount of sulfur (S) in the U / F catalyst 16 based on the travel distance, the amount of sulfur in the fuel, and the like. In another example, the ECU 100 determines whether or not the S poisoning regeneration control should be performed by estimating the purification ability of the U / F catalyst 16. In this case, the ECU 100 estimates the purification capability of the U / F catalyst 16 based on the output of a NOx sensor provided in the exhaust passage 11 and the like. If there is an S poisoning regeneration control request (step S101; Yes), the process proceeds to step S102. If there is no S poisoning regeneration control request (step S101; No), the process exits the flow.

  In step S102, the ECU 100 determines whether or not the SOC of the battery 500 is equal to or less than a predetermined value A. In this case, ECU 100 makes a determination based on a detection signal acquired from SOC sensor 600. This determination is made because the battery 500 is charged in the S poisoning regeneration control, and therefore it is desirable that the SOC of the battery 500 has some allowance in order to prevent overcharging of the battery 500 and the like. It is. If the SOC is equal to or less than the predetermined value A (step S102; Yes), the process proceeds to step S103. If the SOC is greater than the predetermined value A (step S102; No), the process exits the flow. Note that the determination in step S102 may be performed based on the battery voltage instead of the SOC of the battery 500.

  In step S103, the ECU 100 determines whether or not the request output from the driver is equal to or greater than the S poisoning regeneration permission output. In this case, the ECU 100 determines the required output based on the detection signal of the accelerator opening sensor 700 or the like. This determination is made because the output that can be regenerated to the maximum by the motor MG1 is generally determined. Therefore, if the required output is not more than a certain level, the output of the engine 200 causes the U / F catalyst 16 to This is because the output required to raise the temperature may not be reached. If the requested output is equal to or greater than the S poisoning regeneration permission output (step S103; Yes), the process proceeds to step S104. If the requested output is less than the S poisoning regeneration permission output (step S103; No), the process Exit the flow.

  In step S104, the ECU 100 determines whether or not the catalyst temperature of the U / F catalyst 16 is equal to or higher than a predetermined temperature. Here, ECU 100 determines whether or not the catalyst temperature is a temperature at which it is necessary to raise the temperature by performing S poisoning regeneration temperature raising control (control executed in subsequent step S105). In other words, when the S poisoning regeneration temperature increase control is already executed, the S poison regeneration temperature increase control may be terminated (a situation where the catalyst temperature does not need to be increased). It is determined whether or not. In this case, the ECU 100 makes a determination based on the temperature (corresponding to the detection signal S17) acquired from the temperature sensor 17. When the catalyst temperature is equal to or higher than the predetermined temperature (step S104; Yes), the process proceeds to step S106. In this case, it can be said that it is not necessary to execute S poisoning regeneration temperature increase control. On the other hand, when the catalyst temperature is lower than the predetermined temperature (step S104; No), the process proceeds to step S105. In this case, it can be said that S poisoning regeneration temperature increase control needs to be executed.

  In step S105, the ECU 100 executes S poisoning regeneration temperature increase control. Specifically, ECU 100 executes control to increase the output of engine 200 from the required output so that the catalyst temperature is raised to a predetermined temperature. In this case, ECU 100 increases the load / rotation speed of engine 200. Furthermore, ECU 100 causes battery 500 to be charged by causing motor MG1 to regenerate an output corresponding to the difference between the output of engine 200 and the required output. When the above process ends, the process proceeds to step S106.

  In step S106, the ECU 100 executes S poisoning regeneration A / F control. That is, the ECU 100 executes bank control. Specifically, the ECU 100 performs control to cause lean combustion of one of the banks 8L and 8R and rich combustion of the other to make the air / fuel ratio of the exhaust gas supplied to the U / F catalyst 16 stoichiometric and U / F React with F catalyst 16. Then, the process proceeds to step S107.

  In step S107, the ECU 100 calculates an S poisoning regeneration execution integrated gas amount. That is, the ECU 100 integrates the gas amount (corresponding to the intake air amount) from the start of the S poison regeneration control. Then, the process proceeds to step S108.

  In step S108, the ECU 100 determines whether or not the S poisoning regeneration execution integrated gas amount calculated in step S107 is equal to or greater than a predetermined value B. Here, the ECU 100 determines whether or not the execution of the S poisoning regeneration control may be terminated. If the S poisoning regeneration execution integrated gas amount is equal to or greater than the predetermined value B (step S108; Yes), the process proceeds to step S109. In step S109, the ECU 100 ends the execution of the S poisoning regeneration control. Then, the process exits the flow. On the other hand, if the S poisoning regeneration execution integrated gas amount is less than the predetermined value B (step S108; No), the process exits the flow. In this case, the S poisoning regeneration control is continued without ending the S poisoning regeneration control.

  According to the S poisoning regeneration control process according to the first embodiment described above, the temperature of the U / F catalyst 16 is increased quickly in order to perform the S poisoning regeneration temperature increase control when the S poison regeneration control is executed. It is possible to reduce the S poisoning regeneration control time. In addition, since the battery 500 is charged during the S poisoning regeneration control, fuel consumption can be ensured.

[Second Embodiment]
Next, an S poisoning regeneration control method according to the second embodiment will be described.

  Also in the second embodiment, as in the first embodiment, during the S poisoning regeneration control, the output of the engine 200 is requested output only when the requested output in the engine 200 is equal to or greater than the S poisoning regeneration permission output. S poisoning regeneration temperature increase control is executed. However, in the second embodiment, during the execution of the S poisoning regeneration control, when the requested output becomes less than the S poisoning regeneration permission output, the engine 200 output is increased from the requested output for a predetermined time. This is different from the first embodiment in that control to maintain is performed.

  That is, in the second embodiment, when there is a short-term decrease in the required output during the S poisoning regeneration control, that is, during the S poisoning regeneration control, the requested output is greater than or equal to the S poisoning regeneration permission output. When the condition (hereinafter, simply referred to as “regeneration condition”) is temporarily deviated, the S poisoning regeneration temperature increase control is continued without stopping the S poisoning regeneration temperature increase control. Specifically, the ECU 100 counts up the counter when the requested output becomes less than the S poisoning regeneration permission output, and continues the S poisoning regeneration temperature increase control when the counter is less than the predetermined value. If it is equal to or greater than the predetermined value, the S poisoning regeneration temperature increase control is stopped. The predetermined value used when determining the counter corresponds to the predetermined time described above. By performing such control, it is possible to suppress a decrease in the catalyst temperature.

  Here, with reference to FIG. 5, the S poisoning reproduction | regeneration control method which concerns on 2nd Embodiment is demonstrated concretely. In the graph shown in FIG. 5, time is shown on the horizontal axis. Specifically, FIG. 5A shows on / off of the S poisoning regeneration flag, FIG. 5B shows the load factor, FIG. 5C shows the rotation speed of the engine 200, and FIG. (D) has shown the vehicle speed. FIG. 5 (e) shows the output of the engine 200, FIG. 5 (f) shows the SOC of the battery 500, FIG. 5 (g) shows the catalyst temperature of the U / F catalyst 16, and FIG. ) Shows a counter that is counted up when the regeneration condition of the S poisoning regeneration control is not met. Specifically, in FIG. 5E, the solid line Q1 indicates the output of the engine 200, the alternate long and short dash line Q2 indicates the drive wheel output, and the broken line indicates the S poisoning regeneration permission output. In FIG. 5H, a broken line C indicates a predetermined value (hereinafter referred to as “predetermined value C”) used for determination of the counter.

  In this case, at time t20, the S poisoning regeneration flag is on, and the S poisoning regeneration temperature increase control is executed. Specifically, as indicated by a solid line Q1 in FIG. 5 (e), the ECU 100 executes control to maintain the output of the engine 200 at or above the required output at time t20. Thereafter, at time t21, the requested output of the engine 200 becomes less than the S poisoning regeneration permission output. Therefore, the ECU 100 starts counting up the counter as shown in FIG. In this case, since the counter has just started to be counted up (that is, because the counter is less than the predetermined value C), at time t21, the ECU 100 shows the engine 200 as indicated by the solid line Q1 in FIG. Keep the output up. That is, the S poisoning regeneration temperature increase control is continued.

  Thereafter, the state in which the requested output is less than the S poisoning regeneration permission output continues until time t22, and the requested output of the engine 200 becomes equal to or higher than the S poisoning regeneration permission output at time t22. Therefore, at time t22, the ECU 100 resets the counter (sets the counter to 0) as shown in FIG. In this case, from time t21 to time t22, the requested output is less than the S poisoning regeneration permission output, but the counter does not exceed the predetermined value C. Therefore, ECU 100 maintains a state where the output of engine 200 is increased from time t21 to time t22, as indicated by solid line Q1 in FIG. By executing such control, as shown in FIG. 5G, the catalyst temperature is maintained substantially constant from time t21 to time t22, that is, a decrease in the catalyst temperature is suppressed. Note that the drive wheel output decreases in accordance with the required output as indicated by the alternate long and short dash line Q2 in FIG. 5 (e), but the output of the engine 200 is maintained as indicated by the solid line Q1. ), The SOC of the battery 500 tends to increase.

  Next, with reference to FIG. 6, the S poisoning regeneration control process according to the second embodiment will be described. FIG. 6 is a flowchart showing the S poisoning regeneration control process according to the second embodiment. This process is repeatedly executed by the ECU 100. Note that the processing of steps S201 to S203 is the same as the processing of steps S101 to S103 shown in FIG. 4, and the processing of steps S207 to S212 is the same as the processing of steps S104 to S109 shown in FIG. The description of is omitted.

  Also in the second embodiment, it is determined whether or not the requested output is equal to or higher than the S poisoning regeneration permission output (step S203). If the requested output is equal to or greater than the S poisoning regeneration permission output (step S203; If yes, the process proceeds to step S204, and if the requested output is less than the S poisoning regeneration permission output (step S203; No), the process proceeds to step S205. In step S204, the ECU 100 resets the counter (that is, resets the counter) assuming that the regeneration condition is satisfied. Then, the process proceeds to step S207.

  On the other hand, in step S205, the ECU 100 counts up the counter on the assumption that the regeneration condition is not satisfied. Then, the process proceeds to step S206.

  In step S206, the ECU 100 determines whether or not the counter is less than a predetermined value C. Here, the ECU 100 determines whether or not the regeneration condition is temporarily out of the S poisoning regeneration control. In other words, it is determined whether or not the decrease in the required output is short-term. If the counter is less than the predetermined value C (step S206; Yes), the process proceeds to step S207. In this case, the ECU 100 determines that the decrease in the required output is short-term, and executes the processes after step S207. That is, the S poisoning regeneration temperature increase control is continued. On the other hand, when the counter is equal to or greater than the predetermined value C (step S206; No), the process exits the flow. In this case, the ECU 100 determines that the decrease in the required output is not short-term, and stops the S poisoning regeneration temperature increase control and the like.

  According to the S poisoning regeneration control process according to the second embodiment described above, since the S poisoning regeneration temperature increase control can be continued when temporarily deviating from the regeneration condition of the S poison regeneration control, the catalyst temperature is lowered. Can be effectively suppressed. Therefore, it is possible to effectively shorten the S poisoning regeneration control time.

  In addition, when temporarily deviating from the regeneration conditions in the S poison regeneration control, it is preferable to execute the S poison regeneration regeneration temperature control based on the SOC while monitoring the SOC of the battery 500. By doing so, it is possible to effectively prevent the battery 500 from being overcharged.

[Third Embodiment]
Next, an S poisoning regeneration control method according to the third embodiment will be described.

  Also in the third embodiment, as in the first and second embodiments, the engine 200 is used only when the required output in the engine 200 is equal to or higher than the S poisoning regeneration permission output during the S poisoning regeneration control. S poisoning regeneration temperature increase control is executed to raise the output of the output from the required output. Similarly to the second embodiment, if the regeneration condition in the S poison regeneration control is temporarily out of the S poison regeneration control, the S poison regeneration temperature increase control is continued. However, in the third embodiment, when the S poisoning regeneration control is executed, it is better to stop the operation of the engine 200 than to operate the engine 200 and flow exhaust gas to the U / F catalyst 16 (that is, U In the first embodiment and the second embodiment, the operation of the engine 200 is stopped when the required output is such that the temperature of the U / F catalyst 16 does not decrease). Different from form. Specifically, in the third embodiment, when the load of the engine 200 is in a considerably low region during the S poisoning regeneration control, the engine 200 is stopped and the EV traveling is executed by the motor MG2. By doing so, it is possible to prevent the exhaust gas whose temperature has been lowered due to the low load region from being supplied to the U / F catalyst 16, and it is possible to appropriately suppress the decrease in the catalyst temperature.

  More specifically, in the third embodiment, the ECU 100 stops the engine 200 and executes EV traveling when the required output becomes approximately 0 when the S poisoning regeneration control is executed. For example, the ECU 100 executes such control that stops the engine 200 when the request output temporarily becomes approximately 0 during the S poisoning regeneration control (when the vehicle stops due to a red light or the like). . On the other hand, when executing the S poisoning regeneration control, if the requested output is not substantially zero and the requested output is less than the S poisoning regeneration permission output, the ECU 100, as in the second embodiment described above, The count is incremented, and the S poisoning regeneration temperature increase control is continued or stopped based on whether or not the counter is less than a predetermined value C.

  Here, with reference to FIG. 7, the S poisoning reproduction | regeneration control method which concerns on 3rd Embodiment is demonstrated concretely. In the graph shown in FIG. 7, time is shown on the horizontal axis. Specifically, FIG. 7A shows on / off of the S poisoning regeneration flag, FIG. 7B shows the load factor, FIG. 7C shows the rotational speed of the engine 200, and FIG. (D) has shown the vehicle speed. 7E shows the output of the engine 200, FIG. 7F shows the SOC of the battery 500, FIG. 7G shows the catalyst temperature of the U / F catalyst 16, and FIG. ) Shows a counter that is counted up when the regeneration condition of the S poisoning regeneration control is not met. Specifically, in FIG. 7 (e), the solid line R1 indicates the output of the engine 200, the alternate long and short dash line R2 indicates the drive wheel output, and the broken line indicates the S poisoning regeneration permission output. In FIG. 7H, a broken line C indicates a predetermined value used for the counter determination.

  In this case, at time t30, the S poisoning regeneration flag is on, and the S poisoning regeneration temperature increase control is executed. Specifically, as indicated by the solid line R1 in FIG. 7 (e), the ECU 100 executes control for maintaining the output of the engine 200 at or above the required output at time t30. Thereafter, at time t31, the requested output of the engine 200 becomes less than the S poisoning regeneration permission output. Therefore, the ECU 100 starts counting up the counter as shown in FIG. In this case, since the counter has just started counting up (that is, because the counter is less than the predetermined value C), at time t31, the ECU 100 indicates that the engine 200 is in the state shown by the solid line R1 in FIG. Keep the output up. That is, the S poisoning regeneration temperature increase control is continued.

  Thereafter, the requested output becomes approximately 0 at time t32. Therefore, the ECU 100 sets the output of the engine 200 to approximately 0, that is, stops the engine 200, as indicated by a solid line R1 in FIG. Further, at time t32, ECU 100 stops counting up the counter as shown in FIG. 7 (h). Next, at time t <b> 33, the requested output is not substantially 0 (that is, becomes greater than 0). Therefore, ECU 100 resumes operation of engine 200. In this case, since the required output is not substantially 0 and the counter is less than the predetermined value C, the ECU 100 controls the output of the engine 200 to be higher than the required output as indicated by the solid line R1 in FIG. (S poisoning regeneration temperature increase control) is executed. Further, at time t33, the ECU 100 resumes counting up as shown in FIG. 7 (h).

  Thereafter, the state where the requested output is less than the S poisoning regeneration permission output continues until time t34, and the requested output of the engine 200 becomes equal to or higher than the S poisoning regeneration permission output at time t34. Therefore, at time t34, the ECU 100 resets the counter (sets the counter to 0) as shown in FIG. In this case, from time t33 to time t34, the requested output is less than the S poisoning regeneration permission output, but the counter does not exceed the predetermined value C. Therefore, ECU 100 maintains a state where the output of engine 200 is increased from time t33 to time t34, as indicated by solid line R1 in FIG. By executing the control as described above, as shown in FIG. 7G, the catalyst temperature is maintained substantially constant from time t31 to time t34, that is, a decrease in the catalyst temperature is suppressed.

  Next, the S poisoning regeneration control process according to the third embodiment will be described with reference to FIG. FIG. 8 is a flowchart showing the S poisoning regeneration control process according to the third embodiment. This process is repeatedly executed by the ECU 100. The processes in steps S301 to S304 are the same as the processes in steps S201 to S204 shown in FIG. 6, and the processes in steps S309 to S314 are the same as the processes in steps S207 to S212 shown in FIG. The description of is omitted. Here, the processing of steps S305 to S308 will be mainly described.

  The process of step S305 is executed when the requested output is less than the S poisoning regeneration permission output (step S303; No). Specifically, in step S305, ECU 100 determines whether or not the requested output is greater than zero. In other words, the ECU 100 determines whether or not it corresponds to a case where the operation is performed in a region where the load is considerably low. If the request output is greater than 0 (step S305; Yes), the process proceeds to step S306. If the request output is 0 or less (step S305; No), the process proceeds to step S308.

  In step S306, the ECU 100 counts up the counter without stopping the engine 200 because the requested output is less than the S poisoning regeneration permission output but greater than 0. Then, the process proceeds to step S307.

  In step S307, the ECU 100 determines whether or not the counter is less than the predetermined value C. Here, the ECU 100 determines whether or not the regeneration condition in the S poisoning regeneration control is temporarily deviated during the S poisoning regeneration control. In other words, it is determined whether or not the decrease in the required output is short-term. If the counter is less than the predetermined value C (step S307; Yes), the process proceeds to step S309. In this case, the ECU 100 determines that the decrease in the required output is short-term, and executes the processes after step S309. That is, the S poisoning regeneration temperature increase control is continued. On the other hand, when the counter is equal to or greater than the predetermined value C (step S307; No), the process exits the flow. In this case, the ECU 100 determines that the decrease in the required output is not short-term, and stops the S poisoning regeneration temperature increase control and the like.

  On the other hand, in step S308, since the required output is 0 or less (that is, the required output is 0), ECU 100 stops engine 200. Since this corresponds to a case where the operation is performed in a region where the load is considerably low, it is better to stop the operation of the engine 200 than to operate the engine 200 and flow exhaust gas to the U / F catalyst 16. This is because the temperature of the / F catalyst 16 is considered not to decrease. When ECU 100 is thus stopped, ECU 100 executes EV traveling by motor MG2. When the above processing ends, the processing exits the flow.

  According to the S poisoning regeneration control process according to the third embodiment described above, since the engine 200 is stopped when the required output becomes approximately zero during the S poison regeneration control, the exhaust gas whose temperature has decreased is reduced to U / F catalyst 16 can be suppressed, and a decrease in catalyst temperature can be appropriately suppressed. Therefore, it is possible to effectively shorten the S poisoning regeneration control time. Further, since the engine 200 is stopped when the required output becomes approximately 0, the sound and vibration of the engine 200 are hardly generated at this time, so that the driver can be prevented from feeling uncomfortable.

  In the above description, the example is shown in which the engine 200 is stopped when the required output becomes approximately zero during the S poisoning regeneration control. However, the present invention is not limited to this. In another example, the engine 200 can be stopped when the required output is reduced to a predetermined value larger than 0 during the S poisoning regeneration control. That is, when the engine 200 is operated and the exhaust gas is caused to flow through the U / F catalyst 16, the engine 200 is stopped so that the temperature of the U / F catalyst 16 does not decrease. The engine 200 may be stopped.

[Modification]
When performing the S poisoning regeneration control of any of the first to third embodiments described above, the catalyst temperature, the required output, and the battery 500 are set so that the S poisoning regeneration control is completed earliest. It is preferable to control the output of engine 200 based on the SOC or the like. For example, the ECU 100 can operate the engine 200 at a high output so that the temperature of the U / F catalyst 16 is raised earlier, for example, when the SOC of the battery 500 has a margin.

  Further, the present invention is not limited to application to a V-type engine as shown in FIG. 2, but can also be applied to an in-line engine. Furthermore, the present invention is not limited to application to an engine configured using a turbocharger, and can also be applied to a naturally aspirated type engine.

1 shows a schematic configuration of a hybrid vehicle to which an internal combustion engine control device according to an embodiment is applied. 1 shows a schematic configuration of an engine according to the present embodiment. It is a figure for demonstrating concretely the S poison reproduction | regeneration control method which concerns on 1st Embodiment. It is a flowchart which shows the S poison reproduction | regeneration control process which concerns on 1st Embodiment. It is a figure for demonstrating concretely the S poison reproduction | regeneration control method which concerns on 2nd Embodiment. It is a flowchart which shows the S poison reproduction | regeneration control process which concerns on 2nd Embodiment. It is a figure for demonstrating concretely the S poison reproduction | regeneration control method which concerns on 3rd Embodiment. It is a flowchart which shows the S poison reproduction | regeneration control process which concerns on 3rd Embodiment.

Explanation of symbols

3 Intake passage 4L, 4R Turbocharger 8L, 8R Bank (cylinder group)
11, 11L, 11R Exhaust passage 12L, 12R Start catalyst 16 U / F catalyst 100 ECU
200 engine (internal combustion engine)
500 Battery MG1, MG2 Motor

Claims (5)

In a control device for an internal combustion engine that controls a hybrid vehicle that can distribute the output from each of the internal combustion engine and the electric motor to the driving force of the vehicle and charge / discharge of the battery,
When the required output in the internal combustion engine exceeds a predetermined value during the execution of the S poison regeneration control for recovering sulfur poisoning in the catalyst provided in the exhaust passage, the output of the internal combustion engine is determined as the required output. A control apparatus for an internal combustion engine, comprising output control means for performing control to raise the output more than the output.   The output control means maintains a state in which the output of the internal combustion engine is raised above the required output for a predetermined time when the required output becomes less than the predetermined value during the execution of the S poisoning regeneration control. The control apparatus for an internal combustion engine according to claim 1, wherein:   When the S poisoning regeneration control is executed, the required output is such that the temperature of the catalyst does not decrease when the operation of the internal combustion engine is stopped rather than the exhaust gas flowing through the catalyst by operating the internal combustion engine. 3. The control apparatus for an internal combustion engine according to claim 1, further comprising stop control means for stopping the operation of the internal combustion engine in the case of   4. The predetermined value is set based on an output of the internal combustion engine necessary for raising the temperature of the catalyst and an output that can be regenerated by a generator. The control apparatus for an internal combustion engine according to the item.   The output control means performs control to increase the output of the internal combustion engine above the required output when the charge amount of the battery is equal to or less than a predetermined value and the temperature of the catalyst is lower than a predetermined temperature. The control apparatus for an internal combustion engine according to any one of claims 1 to 4.

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