JP2013129286A - Control device of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the performance of an exhaust purification catalyst immediately after starting of a hybrid vehicle by an internal combustion engine.SOLUTION: There is provided a control device of the hybrid vehicle that includes an internal combustion engine and an electric motor, wherein the internal combustion engine includes the catalyst to purify the exhaust gas exhausted from the combustion chamber, and the internal combustion engine is cooled by the cooling water. The control device of this hybrid vehicle is executable of intermittent control to drive the internal combustion engine intermittently. Here, at the starting of the hybrid vehicle, it is decided whether the execution of the intermittent control prohibited or not, based on the cooling water temperature decrease quantity from the engine operation stop immediately before the starting of this hybrid vehicle to the starting point of this hybrid vehicle, and the temperature of the cooling water of the starting point of the hybrid vehicle.

Description

  The present invention relates to a control device for a hybrid vehicle.

  Patent Document 1 discloses a hybrid vehicle including an internal combustion engine and an electric motor. In this hybrid vehicle, intermittent control for starting the internal combustion engine when starting the hybrid vehicle can be executed. The intermittent control described in Patent Document 1 is a control for continuously operating the internal combustion engine by prohibiting execution of intermittent engine operation control (that is, control for intermittently operating the internal combustion engine).

  By the way, the internal combustion engine of the hybrid vehicle described in Patent Document 1 includes a catalyst for purifying exhaust gas discharged from the internal combustion engine. Here, the increase in the temperature of the catalyst when the intermittent control is executed (hereinafter also referred to as “catalyst temperature”) is larger than the increase in the catalyst temperature when the execution of the intermittent control is prohibited. The fuel consumption of the internal combustion engine when is executed is lower than the fuel consumption of the internal combustion engine when execution of intermittent control is prohibited. Conversely, the increase in the catalyst temperature when the execution of the intermittent control is prohibited is smaller than the increase in the catalyst temperature when the intermittent control is executed, but the internal combustion when the execution of the intermittent control is prohibited. The fuel consumption of the engine is higher than the fuel consumption of the internal combustion engine when intermittent control is executed. Therefore, in order to increase the catalyst temperature and obtain high exhaust emission performance (that is, emission performance of exhaust gas discharged from the catalyst), it is preferable to prohibit the execution of intermittent control rather than performing intermittent control. In order to obtain a high fuel efficiency of the internal combustion engine, it is preferable to execute the intermittent control rather than prohibiting the execution of the intermittent control.

  Therefore, in the hybrid vehicle described in Patent Document 1, intermittent control is performed when the catalyst temperature is lower than its activation temperature (that is, the temperature at which the catalyst purifies exhaust gas with a sufficiently high purification rate) at the time of starting the hybrid vehicle. Is prohibited, and intermittent control is executed when the catalyst temperature is equal to or higher than the activation temperature at the start of the hybrid vehicle. That is, in the hybrid vehicle described in Patent Document 1, intermittent control is prohibited only when it is at least necessary to obtain sufficiently high catalyst exhaust purification performance (that is, the performance of the catalyst to purify exhaust gas). By doing so, it is intended to ensure sufficiently high catalyst exhaust purification performance and sufficiently high fuel consumption.

JP 2010-58745 A

  As described above, sufficiently high catalyst exhaust purification performance and sufficiently high in the start-up period of the hybrid vehicle including the internal combustion engine provided with the catalyst (that is, the period until the fixed period elapses from the start time of the hybrid vehicle). There is a demand to balance the fuel consumption of an internal combustion engine. Here, an object of the present invention is to reliably achieve both high catalyst exhaust purification performance and high fuel efficiency of an internal combustion engine during a start-up period of a hybrid vehicle including an internal combustion engine including a catalyst.

  The invention of the present application includes an internal combustion engine and an electric motor, the internal combustion engine includes a catalyst for purifying exhaust gas discharged from a combustion chamber of the internal combustion engine, and the internal combustion engine is cooled by cooling water. The present invention relates to a control device for a hybrid vehicle. And the control apparatus of this invention can perform the intermittent control which operates the said internal combustion engine intermittently. Here, in the present invention, at the time of starting the hybrid vehicle, the amount of decrease in the temperature of the cooling water from the time when the internal combustion engine is stopped immediately before starting the current hybrid vehicle to the time when the hybrid vehicle is started is started. Whether or not to prohibit the execution of the intermittent control is determined based on the cooling water temperature decrease amount and the starting cooling water temperature that is the temperature of the cooling water at the start of the current hybrid vehicle.

  According to the present invention, the following effects can be obtained. That is, the catalyst exhaust purification performance at the start of the hybrid vehicle depends on the catalyst activation partial volume at the start of the hybrid vehicle (that is, the volume of the portion activated in the catalyst). The larger the value, the higher the catalyst exhaust purification performance. Here, according to the research of the inventors of the present application, the catalyst activation partial volume at the start of the hybrid vehicle depends not only on the start-up coolant temperature but also on the start-up coolant temperature decrease, and the start-up coolant temperature decrease is It has been found that the catalyst activation partial volume at the start of the hybrid vehicle is smaller as it is larger. That is, according to the research of the inventors of the present application, even if the cooling water temperature at the start is the same, the catalyst activation partial volume at the start of the hybrid vehicle is smaller as the cooling water temperature decrease amount at the start is larger. It was found that the catalyst exhaust purification performance at the start of the vehicle is low. Here, in the present invention, it is determined whether or not to prohibit the execution of the intermittent control based on the cooling water temperature decrease amount at the start and the cooling water temperature at the start. That is, it is determined whether to prohibit the execution of the intermittent control in consideration of the catalyst exhaust purification performance at the start of the hybrid vehicle more accurately. For this reason, according to the present invention, it is possible to reliably achieve both high catalyst exhaust purification performance and high internal combustion engine fuel efficiency.

  In the above invention, when a threshold value related to the cooling water temperature decrease amount at start is set according to the cooling water temperature at start time, and when the cooling water temperature decrease amount at start time is larger than the threshold value when starting the hybrid vehicle Execution of the intermittent control may be prohibited, and the intermittent control may be performed when the start-up cooling water temperature drop amount is equal to or less than the threshold value when the hybrid vehicle is started.

  Alternatively, in the above invention, a threshold value related to the start-up coolant temperature is set according to the start-up coolant temperature decrease amount, and the start-up coolant temperature is lower than the threshold value when the hybrid vehicle is started. Execution of control may be prohibited, and the intermittent control may be executed when the start-up coolant temperature is equal to or higher than the threshold when the hybrid vehicle is started.

  Alternatively, in the above-described invention, when the volume of the activated part in the catalyst is referred to as a catalyst activated part volume, the amount of cooling water temperature decrease during start-up and the start-up cooling water temperature during start-up of the hybrid vehicle When the catalyst activation partial volume obtained from the above is smaller than a predetermined threshold value, the execution of the intermittent control is prohibited, and the start-up cooling water temperature drop amount and the start-up cooling water temperature are determined from the start of the hybrid vehicle. The intermittent control may be executed when the obtained catalyst activation partial volume is equal to or greater than the predetermined threshold.

  Further, another invention of the present application includes an internal combustion engine and an electric motor, the internal combustion engine includes a catalyst for purifying exhaust gas discharged from a combustion chamber of the internal combustion engine, and the internal combustion engine includes cooling water. It is related with the control apparatus of the hybrid vehicle cooled by. And the control apparatus of this invention can perform the intermittent control which operates the said internal combustion engine intermittently. Here, in the present invention, when the hybrid vehicle is started, the catalyst at the time of start which is the amount of decrease in the temperature of the catalyst from the time when the internal combustion engine is stopped immediately before the start of the current hybrid vehicle to the time when the hybrid vehicle is started this time Whether or not the execution of the intermittent control is prohibited is determined based on the temperature decrease amount and the starting catalyst temperature that is the temperature of the catalyst at the start of the current hybrid vehicle.

  According to the present invention, the following effects can be obtained. That is, as described above, the catalyst exhaust purification performance at the start of the hybrid vehicle depends on the catalyst activation partial volume at the start of the hybrid vehicle. The larger the catalyst activation partial volume, the higher the catalyst exhaust purification performance. Here, according to the research by the inventors of the present application, the catalyst activation partial volume at the start of the hybrid vehicle depends not only on the start catalyst temperature but also on the start catalyst temperature decrease, and the greater the start catalyst temperature decrease, the more hybrid It was found that the catalyst activation partial volume at the start of the vehicle was small. That is, according to the research of the inventors of the present application, even if the catalyst temperature at the start is the same, the catalyst activation partial volume at the start of the hybrid vehicle is smaller as the amount of decrease in the catalyst temperature at the start is larger. It turned out that the catalyst exhaust purification performance at the time of starting was low. Here, in the present invention, it is determined whether to prohibit the execution of the intermittent control based on the starting catalyst temperature decrease amount and the starting catalyst temperature. That is, it is determined whether to prohibit the execution of the intermittent control in consideration of the catalyst exhaust purification performance at the start of the hybrid vehicle more accurately. For this reason, according to the present invention, it is possible to reliably achieve both high catalyst exhaust purification performance and high internal combustion engine fuel efficiency.

  In the above invention, a threshold value related to the starting catalyst temperature decrease amount is set according to the starting catalyst temperature, and the intermittent control is performed when the starting catalyst temperature decrease amount is larger than the threshold value when starting the hybrid vehicle. May be prohibited, and the intermittent control may be executed when the start-up catalyst temperature drop amount is equal to or less than the threshold when the hybrid vehicle is started.

  Alternatively, in the above invention, a threshold value related to the starting catalyst temperature is set according to the starting catalyst temperature decrease amount, and the intermittent control is performed when the starting catalyst temperature is lower than the threshold value when starting the hybrid vehicle. And the intermittent control may be executed when the start-up catalyst temperature is equal to or higher than the threshold when the hybrid vehicle is started.

  Alternatively, in the above invention, when the volume of the activated part of the catalyst is referred to as a catalyst activated part volume, from the amount of decrease in catalyst temperature at start and the catalyst temperature at start when the hybrid vehicle is started When the obtained catalyst activation partial volume is smaller than a predetermined threshold value, the execution of the intermittent control is prohibited, and the catalyst activation obtained from the starting catalyst temperature decrease amount and the starting catalyst temperature when starting the hybrid vehicle. The intermittent control may be executed when the partial volume is equal to or greater than the predetermined threshold.

  In the above invention, when the internal combustion engine is cooled by the cooling water, the temperature of the cooling water decreases from the time when the operation of the internal combustion engine immediately before the start of the current hybrid vehicle is stopped to the time when the current hybrid vehicle is started. The amount of catalyst temperature decrease during start is estimated based on the amount of start-up coolant temperature decrease, and the start-up coolant temperature is determined based on the coolant temperature during start of the current hybrid vehicle. The catalyst temperature may be estimated.

It is the figure which showed the vehicle carrying the hybrid system to which the control apparatus of this invention was applied. It is the figure which showed the internal combustion engine shown by FIG. It is the figure which showed an example of the routine which performs the hybrid vehicle starting time control of 2nd Embodiment. It is the figure which showed an example of the routine which performs the hybrid vehicle starting time control of 3rd Embodiment. It is the figure which showed an example of the routine which performs the hybrid vehicle starting time control of 5th Embodiment.

  Hereinafter, embodiments of the present invention will be described. FIG. 1 shows a vehicle (hereinafter referred to as “hybrid vehicle”) equipped with a hybrid system to which a control device of one embodiment of the present invention (hereinafter referred to as “first embodiment”) is applied. The hybrid system 10 of the first embodiment includes at least an internal combustion engine 11, an electric motor 12, an accelerator pedal 13, an accelerator pedal operation amount sensor 14, a vehicle speed sensor 15, and an electronic control unit (ECU) 16. The internal combustion engine 11 is operated by the combustion of fuel and outputs motive power. As the internal combustion engine 11, for example, a spark ignition internal combustion engine (so-called gasoline engine) or a compression auto-ignition internal combustion engine (so-called so-called gasoline engine). Diesel engine) can be used. The electric motor 12 is driven by electric power and outputs power. The electric motor 12 also functions as a generator that generates electric power using the input power when power is input thereto.

  The hybrid system 10 can selectively or simultaneously output power output from the internal combustion engine 11 and power output from the electric motor 12. The hybrid system 10 can execute intermittent control for intermittently operating the internal combustion engine. When intermittent control is executed, the operation of the internal combustion engine and the motor are performed so that the power of the required power value (that is, the power value required as the power output from the hybrid system) is output from the hybrid system. Drive is controlled. Therefore, when the operation of the internal combustion engine is stopped when the required power value is greater than zero, at least the electric motor is driven.

  In the first embodiment, the power output from the hybrid system 10 is input to the drive shaft 20. The drive shaft 20 is connected to the drive wheels 21 of the vehicle, and the drive wheels 20 of the vehicle are driven to rotate by the power input from the hybrid system 10 to the drive shaft 20. In addition, as the hybrid system of the first embodiment, for example, a series type hybrid system, a parallel type hybrid system, or a series parallel type hybrid system can be adopted.

  The accelerator pedal operation amount sensor 14 outputs an output value corresponding to the accelerator pedal operation amount (that is, the operation amount of the accelerator pedal 13). The output value output from the accelerator pedal operation amount sensor 14 is input to the electronic control device 16. The electronic control unit 16 uses an accelerator pedal operation amount (hereinafter, this accelerator pedal operation amount is referred to as an “accelerator for request torque calculation”) used for calculating the required torque based on the output value input from the accelerator pedal operation amount sensor 14. The operation amount ”is calculated. The required torque means “torque required as torque output from the hybrid system”.

  The vehicle speed sensor 15 outputs an output value corresponding to the vehicle speed (that is, the vehicle speed). The output value output from the vehicle speed sensor 15 is input to the electronic control device 16. The electronic control unit 16 calculates the vehicle speed based on the output value input from the vehicle speed sensor 15.

  The electronic control unit 16 calculates the required torque based on the calculated accelerator pedal operation amount for calculating the required torque, and the required power based on the calculated required torque and the calculated vehicle speed. Calculate the value.

  The electronic control unit 16 controls the operation of the internal combustion engine 11 and the drive of the electric motor 12 so that the power of the required power value is output from the hybrid system 10.

  Further, as shown in FIG. 2, the internal combustion engine 11 is cooled by the cooling water flowing in the cooling water passage 50. Further, the internal combustion engine 11 includes a catalytic converter 42 in which a catalyst 41 is built in the exhaust passage 40. The catalyst 41 is a catalyst that purifies the exhaust gas discharged from the combustion chamber of the internal combustion engine 11.

  As the catalyst 41, for example, when the air-fuel ratio of the exhaust gas flowing into it is the stoichiometric air-fuel ratio or substantially the stoichiometric air-fuel ratio (that is, the oxygen concentration in the exhaust gas flowing into it is the stoichiometric air-fuel ratio in the combustion chamber). When the air-fuel mixture is combusted or substantially coincides with the oxygen concentration in the exhaust gas discharged from the combustion chamber) and the temperature is equal to or higher than the activation temperature. Regardless of what is called a three-way catalyst that simultaneously purifies carbon oxides, hydrocarbons, and nitrogen oxides with a high purification rate, and the air-fuel ratio of the exhaust gas that flows into the catalyst, when its temperature is above its activation temperature A so-called NOx catalyst that purifies nitrogen oxides in exhaust gas with a high purification rate can be employed. In FIG. 2, reference numeral 30 denotes an intake passage.

  Next, the hybrid vehicle start time control of the first embodiment will be described. In the following description, “starting a hybrid vehicle” means “starting a hybrid system for running a hybrid vehicle”. For example, when a so-called ignition switch is turned on, the hybrid vehicle is started. That's right. In the following description, “catalyst exhaust purification performance” means “performance in which the catalyst purifies exhaust gas”, and “starting cooling water temperature drop amount” means “from the time when the engine operation stops immediately before the start of the hybrid vehicle”. "The amount of cooling water temperature decrease until the start of the hybrid vehicle" means "cooling water temperature at start time" means "cooling water temperature at the start time of hybrid vehicle", and "engine operation" means It means “operation of the internal combustion engine”, and “engine power” means “power output from the internal combustion engine”.

  In the first embodiment, at the time of starting the hybrid vehicle, it is determined whether to prohibit the execution of the intermittent control based on the starting cooling water temperature drop at that time and the starting cooling water temperature at that time. . In the first embodiment, when the execution of the intermittent control is prohibited, for example, the continuous control for continuously operating the internal combustion engine is executed.

  According to the first embodiment, the following effects can be obtained. That is, the catalyst exhaust purification performance at the start of the hybrid vehicle depends on the catalyst activation partial volume at the start of the hybrid vehicle (that is, the volume of the portion activated in the catalyst). The larger the value, the higher the catalyst exhaust purification performance. Here, according to the research of the inventors of the present application, the catalyst activation partial volume at the start of the hybrid vehicle depends not only on the start-up coolant temperature but also on the start-up coolant temperature decrease, and the start-up coolant temperature decrease is It has been found that the catalyst activation partial volume at the start of the hybrid vehicle is smaller as it is larger. That is, according to the research of the inventors of the present application, even if the cooling water temperature at the start is the same, the catalyst activation partial volume at the start of the hybrid vehicle is smaller as the cooling water temperature decrease amount at the start is larger. It was found that the catalyst exhaust purification performance at the start of the vehicle is low. Here, in 1st Embodiment, it is determined whether execution of intermittent control is prohibited based on the amount of cooling water temperature reduction at the time of starting, and the temperature of cooling water at the time of starting. That is, it is determined whether to prohibit the execution of the intermittent control in consideration of the catalyst exhaust purification performance at the start of the hybrid vehicle more accurately. For this reason, according to the first embodiment, it is possible to reliably achieve both high catalyst exhaust purification performance and high internal combustion engine fuel efficiency.

  In the intermittent control and the continuous control of the first embodiment, all engine power may be output from the hybrid system when engine operation is performed, or all engine power may not be output from the hybrid system. However, only a part of the engine power may be output from the hybrid system. Further, in the intermittent control and the continuous control of the first embodiment, the electric motor may be driven intermittently or continuously. Further, in the intermittent control and the continuous control according to the first embodiment, all of the power of the motor may be output from the hybrid system when the motor is driven, or all of the power of the motor may not be output from the hybrid system. Alternatively, only a part of the power of the electric motor may be output from the hybrid system.

  In the first embodiment, when the intermittent control is started at the time of starting the hybrid vehicle, the intermittent control may be appropriately terminated in consideration of the catalyst exhaust purification performance. For example, the intermittent control start time The intermittent control is performed when a certain period of time elapses, or when the temperature of the cooling water exceeds a predetermined temperature, or when the catalyst activation partial volume exceeds a predetermined catalyst activation volume part. Is terminated. In addition, when intermittent control is terminated when a certain period of time has elapsed from the start of intermittent control, this certain period of time is sufficient for the temperature of the cooling water to be equal to or higher than a predetermined temperature, or the catalyst It is preferable that the activation partial volume is set to a time sufficient to be equal to or greater than the predetermined catalyst activation volume portion. In addition, when the intermittent control is terminated when the temperature of the cooling water is equal to or higher than a predetermined temperature, the predetermined temperature is a temperature at which the catalyst activation partial volume is equal to or higher than the predetermined catalyst activation volume portion. It is preferable to set to.

  Next, a more specific embodiment (hereinafter referred to as “second embodiment”) of the first embodiment will be described. The configuration and control of the second embodiment not described below are the same as the configuration and control of the first embodiment, respectively, or in view of the configuration and control of the second embodiment described below. Sometimes the configuration and control are naturally derived from the configuration and control of the first embodiment.

  In the second embodiment, in order to determine whether or not the execution of the intermittent control is prohibited at the time of starting the hybrid vehicle, the threshold related to the amount of cooling water temperature decrease at the start time depends on the start time cooling water temperature at that time point. Is set. When the starting coolant temperature decrease amount at that time is larger than the threshold value, execution of intermittent control is prohibited. On the other hand, intermittent control is executed when the amount of cooling water temperature decrease at start-up at that time is equal to or less than the threshold value. In addition, the threshold value regarding the cooling water temperature decrease amount at the start is set to a smaller value as the start-up cooling water temperature is lower.

  Next, an example of a routine for executing the hybrid vehicle start-up control according to the second embodiment will be described. An example of this routine is shown in FIG. This routine is a routine executed when the hybrid vehicle is started.

  When the routine of FIG. 3 is started, first, at step 100, a threshold value ΔTwth relating to the amount of cooling water temperature decrease at start-up is set based on the current coolant temperature at start-up. Next, at step 101, it is determined whether or not the starting coolant temperature decrease amount ΔTw at that time is larger than the threshold value ΔTwth set at step 101 (ΔTw> ΔTwth). Here, when it is determined that ΔTw> ΔTwth, the routine proceeds to step 102. On the other hand, when it is determined that ΔTw> ΔTwth is not satisfied, the routine proceeds to step 106.

  In step 102, execution of intermittent control is prohibited. Next, in step 103, continuous control is started. Next, in step 104, it is determined whether or not the time T that has elapsed since the start of the continuous control in step 103 is equal to or greater than a predetermined time Tth (T ≧ Tth). Here, when it is determined that T ≧ Tth, the routine proceeds to step 105, the continuous control is stopped, and then the routine ends. On the other hand, when it is determined that T ≧ Tth is not satisfied, step 104 is repeated.

  In step 106, intermittent control is started, and then the routine ends.

  In the second embodiment, a threshold value related to the starting coolant temperature may be used instead of the threshold value related to the starting coolant temperature decrease amount. In this case, in order to determine whether or not the execution of the intermittent control is prohibited at the start of the hybrid vehicle, a threshold value related to the start-up coolant temperature is set according to the start-up coolant temperature decrease amount at that time. . When the starting coolant temperature at that time is lower than the threshold, execution of intermittent control is prohibited. On the other hand, when the starting coolant temperature at that time is equal to or higher than the threshold, intermittent control is executed. The threshold value related to the starting coolant temperature is set to a larger value as the starting coolant temperature decrease amount is larger.

  Next, another more specific embodiment of the first embodiment (hereinafter “third embodiment”) will be described. The configuration and control of the third embodiment not described below are the same as the configuration and control of the first embodiment, respectively, or in view of the configuration and control of the third embodiment described below. Sometimes the configuration and control are naturally derived from the configuration and control of the first embodiment. In the following description, “starting period of hybrid vehicle” means “a period until a certain time has elapsed since starting of the hybrid vehicle”, and “catalyst activation partial volume” is “activated in the catalyst”. It means “volume of the part”.

  In the third embodiment, a catalyst activation partial volume required for obtaining a predetermined catalyst exhaust purification performance during the start-up period of the hybrid vehicle is obtained in advance by experiments or the like, and the obtained catalyst activation partial volume is predetermined. The catalyst activation partial volume is stored in the electronic control unit. Then, at the start of the hybrid vehicle, the catalyst activation partial volume is obtained from the start-up cooling water temperature drop at that time and the start-up cooling water temperature at that time. When the determined catalyst activation partial volume is smaller than the predetermined catalyst activation partial volume, execution of intermittent control is prohibited. On the other hand, when the obtained catalyst activation partial volume is equal to or greater than the predetermined catalyst activation partial volume, intermittent control is executed. The catalyst activation partial volume obtained from the starting cooling water temperature drop amount and the starting cooling water temperature is smaller as the starting cooling water temperature drop amount is larger, and smaller as the starting cooling water temperature is lower.

  Next, an example of a routine for executing the hybrid vehicle start time control of the third embodiment will be described. An example of this routine is shown in FIG. This routine is a routine executed when the hybrid vehicle is started. Also, steps 202 to 206 in FIG. 4 are the same as steps 102 to 106 in FIG.

  When the routine of FIG. 4 is started, first, at step 200, the catalyst activation partial volume Vcat is calculated from the starting cooling water temperature decrease amount at that time and the starting cooling water temperature at that time. Next, in step 201, it is determined whether or not the catalyst activation partial volume Vcat calculated in step 200 is smaller than a predetermined catalyst activation partial volume Vcatth (Vcat <Vcatth). Here, when it is determined that Vcat <Vcatth, the routine proceeds to step 202. On the other hand, when it is determined that Vcat <Vcatth is not satisfied, the routine proceeds to step 206.

  Next, the hybrid vehicle start time control of the fourth embodiment will be described. The configuration and control of the fourth embodiment not described below are the same as the configuration and control of the first embodiment, respectively, or in view of the configuration and control of the fourth embodiment described below. Sometimes the configuration and control are naturally derived from the configuration and control of the first embodiment.

  In the fourth embodiment, at the time of starting the hybrid vehicle, it is determined whether to prohibit the execution of intermittent control based on the starting catalyst temperature decrease amount at that time and the starting catalyst temperature at that time.

  According to the fourth embodiment, the following effects can be obtained. That is, as described above, the catalyst exhaust purification performance at the start of the hybrid vehicle depends on the catalyst activation partial volume at the start of the hybrid vehicle (that is, the volume of the portion activated in the catalyst). The greater the activated partial volume, the higher the catalyst exhaust purification performance. Here, according to the research by the inventors of the present application, the catalyst activation partial volume at the start of the hybrid vehicle depends not only on the start catalyst temperature but also on the start catalyst temperature decrease, and the greater the start catalyst temperature decrease, the more hybrid It was found that the catalyst activation partial volume at the start of the vehicle was small. That is, according to the research of the inventors of the present application, even if the catalyst temperature at the start is the same, the catalyst activation partial volume at the start of the hybrid vehicle is smaller as the amount of decrease in the catalyst temperature at the start is larger. It turned out that the catalyst exhaust purification performance at the time of starting was low. Here, in the fourth embodiment, it is determined whether to prohibit the execution of the intermittent control based on the starting catalyst temperature decrease amount and the starting catalyst temperature. That is, it is determined whether to prohibit the execution of the intermittent control in consideration of the catalyst exhaust purification performance at the start of the hybrid vehicle more accurately. For this reason, according to the fourth embodiment, it is possible to reliably achieve both high catalytic exhaust purification performance and high internal combustion engine fuel efficiency.

  Next, a more specific embodiment (hereinafter, “fifth embodiment”) of the fourth embodiment will be described. The configuration and control of the fifth embodiment not described below are the same as the configuration and control of the first embodiment, respectively, or in view of the configuration and control of the fifth embodiment described below. Sometimes the configuration and control are naturally derived from the configuration and control of the first embodiment.

  In the fifth embodiment, in order to determine whether or not the execution of intermittent control is prohibited at the time of starting the hybrid vehicle, a threshold value related to the amount of catalyst temperature decrease at start is set according to the catalyst temperature at start at that time. The When the starting catalyst temperature decrease amount at that time is larger than the threshold value, execution of intermittent control is prohibited. On the other hand, when the starting catalyst temperature decrease amount at that time is equal to or less than the threshold value, intermittent control is executed. It should be noted that the threshold value related to the starting catalyst temperature decrease amount is set to a smaller value as the starting catalyst temperature is lower.

  Next, an example of a routine for executing the hybrid vehicle start-up control according to the fifth embodiment will be described. An example of this routine is shown in FIG. This routine is a routine executed when the hybrid vehicle is started. Further, steps 302 to 306 in FIG. 5 are the same as steps 102 to 106 in FIG.

  When the routine of FIG. 5 is started, first, at step 300, a threshold value ΔTcatth relating to the starting catalyst temperature decrease amount is set based on the starting catalyst temperature at that time. Next, at step 301, it is judged if the starting catalyst temperature decrease amount ΔTcat at that time is larger than the threshold value ΔTcatth set at step 300 (ΔTcat> ΔTcatth). Here, when it is determined that ΔTcat> ΔTcatth, the routine proceeds to step 302. On the other hand, when it is determined that ΔTcat> ΔTcatth is not satisfied, the routine proceeds to step 306.

  In the fifth embodiment, a threshold value related to the catalyst temperature during start-up may be used instead of the threshold value related to the amount of catalyst temperature decrease during start-up. In this case, in order to determine whether or not the execution of the intermittent control is prohibited at the start of the hybrid vehicle, a threshold value related to the start-up catalyst temperature is set according to the start-up catalyst temperature decrease amount at that time. When the starting catalyst temperature at that time is lower than the threshold value, execution of intermittent control is prohibited. On the other hand, when the starting catalyst temperature at that time is equal to or higher than the threshold value, intermittent control is executed. The threshold value related to the starting catalyst temperature is set to a larger value as the starting catalyst temperature decrease amount is larger.

  Next, another more specific embodiment (hereinafter, “sixth embodiment”) of the fourth embodiment will be described. The configuration and control of the sixth embodiment not described below are the same as the configuration and control of the first embodiment, respectively, or in view of the configuration and control of the sixth embodiment described below. Sometimes the configuration and control are naturally derived from the configuration and control of the first embodiment.

  In the sixth embodiment, a catalyst activation partial volume required for obtaining a predetermined catalyst exhaust purification performance during the start-up period of the hybrid vehicle is obtained in advance by experiments or the like, and the obtained catalyst activation partial volume is predetermined. The catalyst activation partial volume is stored in the electronic control unit. Then, at the start of the hybrid vehicle, the catalyst activation partial volume is obtained from the start-up catalyst temperature decrease amount at that time and the start-up catalyst temperature at that time. When the determined catalyst activation partial volume is smaller than the predetermined catalyst activation partial volume, execution of intermittent control is prohibited. On the other hand, when the obtained catalyst activation partial volume is equal to or greater than the predetermined catalyst activation partial volume, intermittent control is executed. The catalyst activation partial volume obtained from the starting catalyst temperature decrease amount and the starting catalyst temperature is smaller as the starting catalyst temperature decrease amount is larger, and is smaller as the starting catalyst temperature is lower.

  Note that the routine shown in FIG. 4 can be used as an example of a routine for executing the hybrid vehicle start-up control of the sixth embodiment. However, in this case, in step 200, the catalyst activation partial volume Vcat is calculated from the starting catalyst temperature decrease amount at that time and the starting catalyst temperature at that time.

  In the above-described embodiment, the catalyst temperature may be, for example, a catalyst temperature detected by a temperature sensor arranged in the catalytic converter in order to detect the catalyst temperature, or various parameter values representing the operating state of the internal combustion engine. Or a catalyst temperature estimated from the temperature of the cooling water.

  DESCRIPTION OF SYMBOLS 10 ... Hybrid system, 11 ... Internal combustion engine, 12 ... Electric motor, 13 ... Accelerator pedal, 14 ... Accelerator pedal operation amount sensor, 16 ... Electronic control unit, 20 ... Drive shaft, 21 ... Drive wheel, 40 ... Exhaust passage, 41 ... Catalyst, 50 ... Cooling channel

Claims (9)

  A control apparatus for a hybrid vehicle comprising an internal combustion engine and an electric motor, wherein the internal combustion engine comprises a catalyst for purifying exhaust gas discharged from a combustion chamber of the internal combustion engine, and wherein the internal combustion engine is cooled by cooling water In the control apparatus for a hybrid vehicle capable of performing intermittent control for intermittently operating the internal combustion engine, the current time from the time when the internal combustion engine is stopped immediately before the start of the current hybrid vehicle is started when the hybrid vehicle is started. The cooling water temperature decrease amount at the start time that is the amount of decrease in the temperature of the cooling water until the start time of the hybrid vehicle and the cooling water temperature at the start time that is the temperature of the cooling water at the start time of the hybrid vehicle A control apparatus for a hybrid vehicle that determines whether or not to prohibit the execution of the intermittent control based on the control.   2. The control device for a hybrid vehicle according to claim 1, wherein a threshold value related to the cooling water temperature decrease amount at the start is set according to the cooling water temperature at the start time, and the cooling water temperature decrease amount at the start time when the hybrid vehicle is started. The control device for a hybrid vehicle, in which execution of the intermittent control is prohibited when the value is larger than the threshold value, and the intermittent control is executed when the cooling water temperature decrease amount at the start time is equal to or less than the threshold value when the hybrid vehicle is started.   2. The hybrid vehicle control device according to claim 1, wherein a threshold value related to the start-up coolant temperature is set according to the start-up coolant temperature decrease amount, and the start-up coolant temperature is set to the start time of the hybrid vehicle. When the hybrid vehicle is started, execution of the intermittent control is prohibited, and when the hybrid vehicle is started, the intermittent control is executed when the cooling water temperature at the start is equal to or higher than the threshold.   2. The control device for a hybrid vehicle according to claim 1, wherein when the volume of a portion activated in the catalyst is referred to as a catalyst activation partial volume, the amount of cooling water temperature decrease during start-up when the hybrid vehicle is started. And when the catalyst activation partial volume determined from the starting coolant temperature is smaller than a predetermined threshold, execution of the intermittent control is prohibited, and when the hybrid vehicle is started, the start-up coolant temperature decrease amount and the A control apparatus for a hybrid vehicle in which the intermittent control is executed when a catalyst activation partial volume obtained from a starting coolant temperature is equal to or greater than a predetermined threshold.   A control apparatus for a hybrid vehicle comprising an internal combustion engine and an electric motor, wherein the internal combustion engine comprises a catalyst for purifying exhaust gas discharged from a combustion chamber of the internal combustion engine, and wherein the internal combustion engine is cooled by cooling water In the control apparatus for a hybrid vehicle capable of performing intermittent control for intermittently operating the internal combustion engine, the current time from the time when the internal combustion engine is stopped immediately before the start of the current hybrid vehicle is started when the hybrid vehicle is started. The intermittent catalyst temperature reduction amount at the start time which is the amount of decrease in the catalyst temperature until the start time of the hybrid vehicle and the start time catalyst temperature which is the temperature of the catalyst at the start time of the current hybrid vehicle A control apparatus for a hybrid vehicle that determines whether or not execution of control is prohibited.   6. The control apparatus for a hybrid vehicle according to claim 5, wherein a threshold value related to the starting catalyst temperature decrease amount is set according to the starting catalyst temperature, and the starting catalyst temperature decrease amount is set to the threshold value when starting the hybrid vehicle. The control device for the hybrid vehicle is configured such that the intermittent control is prohibited from being executed when the hybrid vehicle is started, and the intermittent control is executed when the start-up catalyst temperature decrease amount is equal to or less than the threshold when the hybrid vehicle is started.   6. The control apparatus for a hybrid vehicle according to claim 5, wherein a threshold value related to the catalyst temperature at start is set according to the amount of decrease in catalyst temperature at start, and the catalyst temperature at start is lower than the threshold when starting the hybrid vehicle. The control apparatus for a hybrid vehicle, wherein execution of the intermittent control is prohibited when it is low, and when the start-up catalyst temperature is equal to or higher than the threshold when the hybrid vehicle is started.   6. The control apparatus for a hybrid vehicle according to claim 5, wherein when the volume of a portion activated in the catalyst is referred to as a catalyst activation partial volume, When the catalyst activation partial volume obtained from the starting catalyst temperature is smaller than a predetermined threshold, the execution of the intermittent control is prohibited, and the starting catalyst temperature decrease amount and the starting catalyst are reduced when the hybrid vehicle is started. A control apparatus for a hybrid vehicle in which the intermittent control is executed when a catalyst activation partial volume determined from temperature is equal to or greater than the predetermined threshold.   The hybrid vehicle control device according to any one of claims 5 to 8, wherein the internal combustion engine is cooled by cooling water, wherein the start-up catalyst temperature drop amount is a value of the internal combustion engine immediately before the start of the current hybrid vehicle. It is estimated on the basis of the cooling water temperature decrease amount at the start time, which is the amount of decrease in the cooling water temperature from the stop time to the start time of the current hybrid vehicle. A control apparatus for a hybrid vehicle, which is estimated based on a starting coolant temperature that is the temperature of the coolant.

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