JP2010069930A - Controller for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller for a hybrid vehicle for inhibiting lowering of catalyst bed temperature at starting of an internal combustion engine, and inhibiting deterioration in exhaust emission. <P>SOLUTION: A starting threshold for starting the internal combustion engine, the threshold being indicated by power required by the internal combustion engine, is set higher than usual when the bed temperature of a catalytic converter detected by a catalyst bed temperature sensor is not higher than the prescribed temperature at which the operation of the internal combustion engine is needed in order to warm up the catalytic converter during EV travel (S103). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

If the catalyst bed temperature lowering condition is satisfied when the internal combustion engine is started, the target power to be output from the internal combustion engine based on the required driving force set with a predetermined output limit until the predetermined return condition is satisfied. Set. Then, after a predetermined return condition is satisfied, it is disclosed to set a target power to be output from the internal combustion engine based on a required driving force that is set by releasing a predetermined output restriction (for example, a patent) Reference 1).
JP 2008-106675 A JP 2003-199208 A JP 2001-037008 A

  Incidentally, in recent years, a large amount of EGR gas has been introduced into an internal combustion engine in order to improve fuel efficiency. When a large amount of EGR gas is introduced into the internal combustion engine in this way, low-temperature exhaust is discharged from the internal combustion engine. Further, when the internal combustion engine is operated in an operating state such as a low load region, low temperature and low flow rate exhaust gas is discharged from the internal combustion engine.

  And if the internal combustion engine is started and the catalyst is warmed up in such a state where the low temperature (and low flow rate) exhaust gas is discharged, the catalyst cannot be warmed up. On the contrary, when the low temperature (and low flow rate) exhaust gas flows into the catalyst, the catalyst bed temperature decreases, and the catalyst cannot purify the exhaust gas and exhausts the exhaust gas, which may deteriorate the exhaust emission.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to suppress a decrease in the bed temperature of the catalyst at the start of the internal combustion engine in the hybrid vehicle control device, resulting in a deterioration in exhaust emission. It is in providing the technique which suppresses doing.

In the present invention, the following configuration is adopted. That is, the present invention
An internal combustion engine as a power source;
A motor that serves as a power source together with the internal combustion engine by the electric energy supplied from the battery and charges the battery by regeneration;
A catalyst disposed in an exhaust passage of the internal combustion engine for purifying exhaust;
Catalyst bed temperature detecting means for detecting the bed temperature of the catalyst;
When only the motor is operating as a power source, the catalyst bed temperature detected by the catalyst bed temperature detecting means is equal to or lower than a predetermined temperature at which the operation of the internal combustion engine is required to warm up the catalyst. In this case, setting means for setting a starting threshold value for starting the internal combustion engine indicated by the power required by the internal combustion engine higher than normal time;
A control device for a hybrid vehicle, comprising:

In the present invention, when only the motor operates as a power source and the bed temperature of the catalyst is equal to or lower than a predetermined temperature, the starting threshold value for starting the internal combustion engine is set higher than normal. For this reason, the internal combustion engine cannot be started even when there is a request for starting the internal combustion engine with a power lower than the start threshold set higher than normal. Therefore, the internal combustion engine is not started when low power is required, for example, when an operation state in a low load region where low temperature and low flow rate exhaust gas is discharged is required. That is, the catalyst is not warmed up by starting the internal combustion engine in a state where the low-temperature (and low-flow) exhaust is discharged. Therefore, when the internal combustion engine is started, low temperature (and low flow rate) exhaust gas does not flow into the catalyst, and it is possible to suppress a decrease in the catalyst bed temperature, and the catalyst cannot exhaust the exhaust gas without purifying the exhaust gas. Can be suppressed, and deterioration of exhaust emission can be suppressed.

In the present invention, the following configuration is adopted. That is, the present invention
An internal combustion engine as a power source;
A motor that serves as a power source together with the internal combustion engine by the electric energy supplied from the battery and charges the battery by regeneration;
A catalyst disposed in an exhaust passage of the internal combustion engine for purifying exhaust;
When only the motor is operating as a power source, the operation state required for the internal combustion engine is such that the internal combustion engine cannot be started in an operation state where the exhaust gas discharged from the internal combustion engine has a low temperature and a low flow rate. Setting means for setting a starting threshold value for starting the internal combustion engine indicated by the power required by the internal combustion engine higher than normal;
A control device for a hybrid vehicle, comprising:

  In the present invention, when only the motor is operating as a power source, the operating state required for the internal combustion engine is such that the internal combustion engine cannot be started in an operating state in which the exhaust discharged from the internal combustion engine has a low temperature and a low flow rate. The starting threshold value for starting the internal combustion engine is set to be higher than normal. For this reason, an internal combustion engine cannot be started in the driving | running state in which the exhaust_gas | exhaustion discharged | emitted from an internal combustion engine requires low temperature and low flow volume as the driving | running state requested | required of an internal combustion engine. That is, the catalyst is not warmed up by starting the internal combustion engine in a state where the exhaust gas is discharged at a low temperature and a low flow rate. Therefore, when the internal combustion engine is started, low temperature and low flow rate exhaust gas does not flow into the catalyst, it is possible to prevent the catalyst bed temperature from being lowered, and the catalyst exhausts exhaust gas without purifying the exhaust gas. Can be suppressed, and deterioration of exhaust emission can be suppressed.

  An EGR passage that takes in a part of exhaust gas from the exhaust passage of the internal combustion engine as EGR gas and recirculates the EGR gas to the intake passage of the internal combustion engine; an EGR valve that is disposed in the EGR passage and controls the amount of EGR gas; And an EGR valve control means for controlling the opening of the EGR valve to the closed side when the internal combustion engine is started by setting the starting threshold value higher than normal by the setting means.

  In the present invention, the opening degree of the EGR valve is controlled to the closed side when the internal combustion engine is started by setting the starting threshold value higher than normal by the setting means. For this reason, the supply of EGR gas from which the internal combustion engine discharges low-temperature exhaust gas is reduced, and the exhaust gas discharged from the internal combustion engine when the internal combustion engine is started becomes high temperature. Therefore, it is possible to warm up the catalyst by starting the internal combustion engine in a state where high-temperature exhaust gas is discharged. Therefore, the bed temperature of the catalyst can be raised early.

  When the internal combustion engine is started after the start threshold is set higher than normal by the setting means, the battery is charged by regeneration of the motor using a part of the power of the internal combustion engine after the start, Control means for increasing the power of the internal combustion engine after startup may be provided.

  In the present invention, since the power of the internal combustion engine after starting is increased, the operating state required for the internal combustion engine after starting becomes an operating state in which the exhaust gas discharged from the internal combustion engine has a high temperature and a high flow rate. Therefore, it is possible to warm up the catalyst by operating the internal combustion engine in a state where exhaust gas having a high temperature and a high flow rate is discharged. Therefore, the bed temperature of the catalyst can be raised early. Further, the battery can be charged by regeneration of the motor.

  The control means increases a required charge amount for charging the battery by regenerating the motor using a part of the power of the internal combustion engine after starting higher than normal, and charges the battery after starting. The power of the internal combustion engine may be increased.

  In the present invention, since the power of the internal combustion engine after starting is further increased, the operating state required for the internal combustion engine after starting becomes an operating state in which the exhaust discharged from the internal combustion engine has a higher temperature and a higher flow rate. Therefore, it is possible to warm up the catalyst by operating the internal combustion engine in a state where exhaust gas at a higher temperature and higher flow rate is discharged. Accordingly, the bed temperature of the catalyst can be raised even earlier. Further, since the required charge amount for charging the battery is made higher than normal, the battery can be charged early.

  According to the present invention, in the control apparatus for a hybrid vehicle, it is possible to suppress a decrease in the bed temperature of the catalyst at the time of starting the internal combustion engine, and it is possible to suppress a deterioration in exhaust emission.

  Specific examples of the present invention will be described below.

<Example 1>
FIG. 1 is a diagram illustrating a schematic configuration of a hybrid vehicle 100 to which a hybrid vehicle control device according to the present embodiment is applied. A hybrid vehicle 100 shown in FIG. 1 includes an axle 110, wheels 120, an ECU 200, an internal combustion engine 300, a motor generator 400, a motor 500, a power split mechanism 600, an inverter 700, and a battery 800.

  The axle 110 is an axis for transmitting the power output from the internal combustion engine 300, the motor generator 400, and the motor 500 to the wheels 120. The wheels 120 are means for transmitting the power transmitted via the axle 110 to the road surface, and are shown as one wheel on each side in FIG. Provided.

  The ECU 200 is an electronic control unit that controls the overall operation of the hybrid vehicle 100. ECU 200 executes various controls according to a control program stored in the ROM.

  The internal combustion engine 300 is a gasoline internal combustion engine having four cylinders 301 shown in FIG. The internal combustion engine 300 is a power source for the hybrid vehicle 100. The detailed configuration of the internal combustion engine 300 will be described later.

  Similar to the internal combustion engine 300, the motor generator 400 functions as an electric motor that becomes a power source of the hybrid vehicle 100. Motor generator 400 also functions as a generator for charging battery 800. The motor generator 400 of this embodiment corresponds to the motor of the present invention.

  The motor 500 functions as an electric motor that assists the driving force of the internal combustion engine 300. The motor 500 of this embodiment also corresponds to a part of the motor of the present invention.

  Motor generator 400 and motor 500 are configured as, for example, a synchronous motor generator, and include a rotor having a plurality of permanent magnets on the outer peripheral surface and a stator around which a three-phase coil that forms a rotating magnetic field is wound. These may be of other types.

The power split mechanism 600 supplies the power of the internal combustion engine 300 to the motor generator 400 and the axle 1.
10 is a planetary gear mechanism that can be distributed to ten.

  Inverter 700 converts the DC electricity extracted from battery 800 into AC electricity and supplies it to motor generator 400 and motor 500, and converts the AC electricity generated by motor generator 400 into DC electricity and supplies it to battery 800. .

  The battery 800 is an electric energy supply source that supplies electric energy that enables the motor generator 400 and the motor 500 to operate, and is a storage battery that can charge the supplied electric energy.

  Next, the internal combustion engine 300 will be described. FIG. 2 is a diagram showing a schematic configuration of the internal combustion engine 300. The internal combustion engine 300 is a water-cooled four-stroke cycle gasoline internal combustion engine having four cylinders 301 shown in FIG.

  A piston 302 is slidably provided in a cylinder 301 of the internal combustion engine 300. An intake port 304 and an exhaust port 305 are connected to the combustion chamber 303 in the upper part of the cylinder 301.

  The intake port 304 is provided with a fuel injection valve 306 that supplies fuel to the combustion chamber 303 in the cylinder 301. The fuel injection valve 306 has a fuel injection direction toward the combustion chamber 303. The fuel injection valve 306 is electrically connected to the ECU 200 and is controlled by the ECU 200.

  The opening of the intake port 304 to the combustion chamber 303 is opened and closed by an intake valve 307, and the opening of the exhaust port 305 to the combustion chamber 303 is opened and closed by an exhaust valve 308. The intake port 304 is connected to the intake passage 309, and the exhaust port 305 is connected to the exhaust passage 310.

  The exhaust passage 310 and the intake passage 309 are connected by an EGR passage 311. The EGR passage 311 takes a part of the exhaust gas from the exhaust passage 310 as EGR gas and recirculates the EGR gas to the intake passage 309. The EGR passage 311 is provided with an EGR valve 312 that controls the amount of EGR gas flowing through the EGR passage 311. The EGR valve 312 is electrically connected to the ECU 200, and the opening degree of the EGR valve 312 is controlled by the ECU 200.

  A catalytic converter 313 is disposed in the exhaust passage 310 on the downstream side of the connection portion with the EGR passage 311. The catalytic converter 313 includes, for example, a three-way catalyst, and purifies exhaust exhausted from the internal combustion engine 300. The catalytic converter 313 of this example corresponds to the catalyst of the present invention.

  A catalyst bed temperature sensor 314 is disposed in the exhaust passage 310 immediately downstream of the catalytic converter 313. The catalyst bed temperature sensor 314 detects the bed temperature of the catalyst converter 313. The catalyst bed temperature sensor 314 is electrically connected to the ECU 200, and the output value of the catalyst bed temperature sensor 314 is input to the ECU 200. The catalyst bed temperature sensor of this embodiment corresponds to the catalyst bed temperature detection means of the present invention.

The internal combustion engine 300 is provided with a crank position sensor 315. The crank position sensor 315 detects the crank angle of the crankshaft of the internal combustion engine 300. The crank position sensor 315 is electrically connected to the ECU 200, and the output value of the crank position sensor 315 is input to the ECU 200. ECU 200 calculates the engine speed of internal combustion engine 300 based on the output value of crank position sensor 315.

  ECU 200 receives the output signals of catalyst bed temperature sensor 314, crank position sensor 315, accelerator position sensor 130, vehicle speed sensor 140, SOC sensor 150 that detects the amount of charge of battery 800, and the like, and includes the operating state of internal combustion engine 300. The state of the hybrid vehicle 100 is determined, and the hybrid vehicle 100 is electrically controlled based on the determined state.

  In hybrid vehicle 100 of FIG. 1, the power distribution of each of internal combustion engine 300, motor generator 400 that mainly functions as a generator, and motor 500 that functions as an electric motor is controlled by ECU 200 and power split mechanism 600, and the traveling state is controlled. Is done. The operation of the hybrid vehicle 100 according to several situations will be described below.

  When the hybrid vehicle 100 is started, the motor 500 driven using the electric energy of the battery 800 functions as an electric motor, the internal combustion engine 300 is cranked by the power of the motor 500, and the internal combustion engine 300 is started.

  When the hybrid vehicle 100 starts, two types of modes are selected according to the charge amount of the battery 800 based on the output signal of the SOC sensor 150. For example, when the battery 800 is sufficiently charged, it is not necessary to charge the battery 800 by the motor generator 400. Therefore, the internal combustion engine 300 is started only for warming up, and the hybrid vehicle 100 is powered by the motor 500. Start by. On the other hand, at the time of starting when the battery 800 is not charged much, the motor generator 400 functions as a generator by regeneration of the motor generator 400 using the power of the internal combustion engine 300, and the hybrid vehicle 100 is charged while the battery 800 is charged. The vehicle starts with the power of the internal combustion engine 300.

  When the hybrid vehicle 100 travels at a low speed or travels lightly on a gentle slope, operating the internal combustion engine 300 deteriorates the efficiency such as the combustion efficiency. Therefore, the fuel injection from the fuel injection valve 306 is stopped and the internal combustion engine is stopped. 300 is stopped, and hybrid vehicle 100 travels only with the power from motor 500 (hereinafter referred to as EV travel). At this time, if the battery 800 is not charged so much, the internal combustion engine 300 is driven only to regenerate the motor generator 400, and the battery 800 is charged by regeneration of the motor generator 400 using the power of the internal combustion engine 300. May be performed.

  In an operating region where the efficiency such as the combustion efficiency of the internal combustion engine 300 is good as in the normal travel of the hybrid vehicle 100, the hybrid vehicle 100 travels mainly by the power of the internal combustion engine 300. At this time, the power of the internal combustion engine 300 is divided into two systems by the power split mechanism 600, one of which is transmitted to the wheels 120 via the axle 110, and the other regeneratively operates the motor generator 400 to generate power. At this time, the motor 500 is driven by the generated electric energy, and the power of the internal combustion engine 300 is assisted by the motor 500. At this time, if the battery 800 is not charged so much, the power of the internal combustion engine 300 is increased, and the electric energy generated by the regeneration of the motor generator 400 using the increased power of the internal combustion engine 300 is increased. The battery 800 may be charged with a part of the electric energy.

  When the hybrid vehicle 100 decelerates, the motor generator 400 is operated as a generator by the regeneration of the motor generator 400 using the power transmitted from the wheels 120 via the axle 110. As a result, the kinetic energy of the wheels 120 is converted into electric energy, the hybrid vehicle 100 is decelerated and the battery 800 is charged (regenerative braking).

  In hybrid vehicle 100 whose operation is changed as described above, internal combustion engine 300 may be stopped, and EV traveling may be performed in which hybrid vehicle 100 travels only with power from motor 500. During the EV traveling of the hybrid vehicle 100, the internal combustion engine 300 is stopped, so that exhaust does not flow into the catalytic converter 313, and it is difficult to maintain the bed temperature of the catalytic converter 313. For this reason, it is desirable to warm up the catalytic converter 313 when the internal combustion engine 300 is started.

  Here, in recent years, a large amount of EGR gas is introduced into the internal combustion engine 300 in order to improve fuel efficiency. When a large amount of EGR gas is introduced into the internal combustion engine 300 in this way, low-temperature exhaust is discharged from the internal combustion engine 300. Further, when the internal combustion engine 300 operates in an operating state such as a low load region, exhaust gas having a low temperature and a low flow rate is discharged from the internal combustion engine 300.

  Then, when the internal combustion engine 300 is started and the catalytic converter 313 is warmed up in such a state where the low temperature (and low flow rate) exhaust gas is discharged, the catalytic converter 313 cannot be warmed up. On the contrary, when low temperature (and low flow rate) exhaust gas flows into the catalytic converter 313, the bed temperature of the catalytic converter 313 decreases and the catalyst becomes inactive, and the catalytic converter 313 cannot exhaust the exhaust gas and exhausts the exhaust gas. As a result, exhaust emission may deteriorate. Thus, even when the internal combustion engine 300 is started, the catalytic converter 313 may not be warmed up.

  Therefore, in the present embodiment, the bed temperature of the catalytic converter 313 detected by the catalyst bed temperature sensor 314 during the EV running in which only the motor 500 (or the motor generator 400) operates as a power source causes the catalytic converter 313 to When the temperature is equal to or lower than a predetermined temperature at which the operation of the internal combustion engine 300 is required for warming up, a start threshold (engine start threshold) for starting the internal combustion engine 300 indicated by the power required by the internal combustion engine 300 is set from a normal time. Also set to high.

  Here, if the bed temperature of the catalytic converter 313 is a predetermined temperature or lower, the temperature is a threshold value at which the operation of the internal combustion engine 300 is required to warm up the catalytic converter 313.

  According to this embodiment, when the vehicle is running on EV and the bed temperature of the catalytic converter 313 is equal to or lower than a predetermined temperature, the starting threshold value for starting the internal combustion engine 300 is set higher than normal. For this reason, the internal combustion engine 300 cannot be started even if there is a start request for the internal combustion engine 300 with a power lower than the start threshold value set higher than normal. Therefore, the internal combustion engine 300 is not started with low power, for example, when an operation state in a low load region where exhaust at a low temperature and a low flow rate is discharged is required. That is, the catalytic converter 313 is not warmed up by starting the internal combustion engine 300 in a state where the low temperature (and low flow rate) exhaust gas is discharged. Therefore, when the internal combustion engine 300 is started, low-temperature (and low-flow) exhaust does not flow into the catalytic converter 313, and it is possible to suppress a decrease in the bed temperature of the catalytic converter 313, and the catalytic converter 313 can purify the exhaust. It is possible to suppress exhaust gas from being exhausted, and to suppress deterioration in exhaust emission.

For example, if the starting threshold value for starting the internal combustion engine 300 is set as normal when the bed temperature of the catalytic converter 313 is equal to or lower than a predetermined temperature during EV traveling, the broken line in FIG. 3 is obtained. . That is, the internal combustion engine 300 is started even in a case where an operation state in a low load region in which exhaust at a low temperature and a low flow rate temporarily exceeding the normal start threshold is exhausted is required. As a result, the internal combustion engine 300 is started and the catalytic converter 313 is warmed up even in a state where exhaust at a low temperature and a low flow rate is discharged. Therefore, the internal combustion engine 300
Is started and the low temperature and low flow rate exhaust gas flows into the catalytic converter 313, the bed temperature of the catalytic converter 313 is lowered. Then, the catalytic converter 313 that has become inactive in the catalyst cannot exhaust the exhaust gas and exhausts the exhaust gas, resulting in a worse exhaust emission. Further, the operation of the internal combustion engine 300 in a state where the low-temperature and low-flow exhaust gas is discharged in this way causes the bed temperature of the catalytic converter 313 to decrease. Therefore, after that, even if the internal combustion engine 300 is stopped again and the internal combustion engine 300 is started in a state where the exhaust gas is discharged at a high temperature and a high flow rate, the catalytic converter 313 starts from the state where the bed temperature of the catalytic converter 313 is lowered. Will warm up. For this reason, it takes time to warm up the catalytic converter 313.

  On the other hand, when the floor temperature of the catalytic converter 313 is equal to or lower than a predetermined temperature during EV traveling as in this embodiment, if the start threshold value for starting the internal combustion engine 300 is set higher than normal, As shown by the solid line in FIG. That is, when an operation state in a low load region in which exhaust at a low temperature and a low flow rate temporarily exceeding the normal start threshold value is required, the start threshold value set higher is not exceeded. Is not started, and EV travel is continued. Then, since the internal combustion engine 300 is not started in a state where the low temperature and low flow rate exhaust gas is discharged, the low temperature and low flow rate exhaust gas does not flow into the catalytic converter 313, and the bed temperature of the catalytic converter 313 decreases. Can be suppressed. That is, the bed temperature of the catalytic converter 313 can be maintained as it is. Further, after that, when an operation state is required in which exhaust gas having a high temperature and a high flow rate exceeding the preset start threshold is exhausted, the internal combustion engine 300 is started and the bed temperature of the catalytic converter 313 is maintained. Since the catalytic converter 313 is warmed up from the state, the catalytic converter 313 can be warmed up early.

  In this embodiment, when the internal combustion engine 300 is started with the start threshold set higher than normal, the opening of the EGR valve 312 is controlled to be fully closed. In this case, the opening degree of the EGR valve 312 may be controlled not only to be fully closed but also to the closed side.

  According to the present embodiment, when the internal combustion engine 300 is started with the start threshold set higher than normal, the opening degree of the EGR valve 312 is controlled to be fully closed. For this reason, the supply of EGR gas that exhausts low-temperature exhaust gas is eliminated, and the exhaust gas exhausted from the internal combustion engine 300 at the time of starting the internal combustion engine 300 becomes high temperature. Therefore, the internal combustion engine 300 can be started in a state where high-temperature exhaust gas is discharged, and the catalytic converter 313 can be warmed up. Therefore, the bed temperature of the catalytic converter 313 can be raised early.

  Note that, when the opening degree of the EGR valve 312 is controlled to be fully closed as described above, the fuel consumption is reduced due to the absence of the supply of EGR gas. Is changed from a broken line to a solid line as indicated by an arrow in FIG. 4 to maintain fuel consumption. That is, in the normal state, the operation line is set as indicated by a broken line on the NV line shifted from the fuel efficiency optimal line due to NV (noise vibration) countermeasures. This operating line is brought closer to the optimum fuel consumption line as shown by the solid line by improving combustion due to the absence of supply of EGR gas. Thus, by bringing the operation line closer to the fuel efficiency optimum line, the fuel efficiency is improved and the decrease in fuel efficiency due to the absence of the supply of EGR gas is offset.

  Further, in this embodiment, when the internal combustion engine 300 is started after the start threshold is set higher than normal, the battery 800 is removed by regeneration of the motor generator 400 using a part of the power of the internal combustion engine 300 after the start. Charging was performed, and the power of the internal combustion engine 300 after starting was increased.

According to the present embodiment, since the power of the internal combustion engine 300 after the start is increased, the operation state required for the internal combustion engine 300 after the start is an operation state in which the exhaust discharged from the internal combustion engine 300 has a higher temperature and a higher flow rate. It becomes. Therefore, the internal combustion engine 300 can be operated in a state where exhaust gas at a higher temperature and higher flow rate is discharged, and the catalytic converter 313 can be continuously warmed up. Therefore, the bed temperature of the catalytic converter 313 can be raised early. At the same time, the battery 800 is charged by regeneration of the motor generator 400, and the electric energy of the battery 800 that has been consumed due to the increased EV travel amount can be recovered by setting the starting threshold value higher than normal.

  Furthermore, in the present embodiment, the required charge amount for charging the battery 800 when charging the battery 800 by regeneration of the motor generator 400 using a part of the power of the internal combustion engine 300 after starting is made higher than usual. The power of the internal combustion engine 300 after starting is further increased.

  According to the present embodiment, since the power of the internal combustion engine 300 after startup is further increased, the operating state required for the internal combustion engine 300 after startup is such that the exhaust discharged from the internal combustion engine 300 has a higher temperature and a higher flow rate. The driving state becomes. Therefore, the catalytic converter 313 can be warmed up by operating the internal combustion engine 300 in a state where exhaust gas at a higher temperature and higher flow rate is discharged. Therefore, the bed temperature of catalytic converter 313 can be raised even earlier. In addition, since the required charge amount for charging the battery 800 is set higher than normal, the battery 800 can be charged early.

  Next, a control routine when starting the internal combustion engine 300 according to this embodiment will be described. FIG. 5 is a flowchart showing a control routine when starting the internal combustion engine 300 according to this embodiment. This routine is repeatedly executed every predetermined time.

  In step S101, it is determined whether or not the hybrid vehicle 100 is traveling on an EV.

  If an affirmative determination is made in step S101 that the vehicle is running EV, the process proceeds to step S102. If a negative determination is made in step S101 that the vehicle is not traveling EV, this routine is temporarily terminated.

  In step S102, it is determined whether or not the bed temperature of the catalytic converter 313 is equal to or lower than a predetermined temperature. The bed temperature of the catalytic converter 313 is detected by a catalyst bed temperature sensor 314. Here, the predetermined temperature is determined in advance.

  If it is determined in step S102 that the bed temperature of the catalytic converter 313 is equal to or lower than the predetermined temperature, the process proceeds to step S103. If it is determined in step S102 that the bed temperature of the catalytic converter 313 is not equal to or lower than the predetermined temperature, this routine is temporarily ended.

  In step S103, the start threshold (engine start threshold) is set higher than normal. The starting threshold value to be set high is determined in advance. In addition, ECU200 which performs the process of step S101-S103 corresponds to the setting means of this invention.

  In step S104, it is determined whether or not the internal combustion engine 300 can be started. It is determined that the internal combustion engine 300 can be started when the power required for starting the internal combustion engine 300 exceeds a start threshold value higher than the normal time set in step S103.

When it is determined in step S104 that the internal combustion engine 300 can be started, the process proceeds to step S105. If it is determined in step S104 that the internal combustion engine 300 cannot be started, this routine is temporarily terminated.

  In step S105, the internal combustion engine 300 is started.

  In step S106, the opening degree of the EGR valve 312 is controlled to be fully closed. The ECU 200 that executes the processing of this step corresponds to the EGR valve control means of the present invention.

  In step S107, the operating line of the internal combustion engine 300 is changed from the broken line shown in FIG.

  In step S108, the required charge amount for charging battery 800 is set higher than normal.

  In step S109, the motor generator 400 is regenerated using a part of the power of the internal combustion engine 300. At this time, the required charge amount for charging the battery 800 is set to be higher than normal in step S108. As a result, the target power of the internal combustion engine 300 increases, and the power of the internal combustion engine 300 after startup can be increased. The ECU 200 that executes the processes of steps S108 to S109 corresponds to the control means of the present invention.

  In step S110, it is determined whether or not the warm-up of the catalytic converter 313 has been completed. When the output value of the catalyst bed temperature sensor 314 exceeds the warm-up end value, it is determined that the warm-up of the catalytic converter 313 has been completed. The warm-up end value is determined in advance.

  If it is determined affirmative in step S110 that the warm-up has been completed, the process proceeds to step S111. If it is determined in step S110 that the warm-up has not ended, the process returns to step S109.

  In step S111, various settings in this routine are canceled and the normal control is resumed. That is, the starting threshold value is returned to the normal one. The EGR valve 312 is returned from the fully closed state to the normal control. The changed solid operation line of the internal combustion engine 300 is returned to the normal broken operation line. Return the requested charge to the normal amount. The regeneration of the motor generator 400 using a part of the motive power of the internal combustion engine 300 is terminated, and the hybrid vehicle 100 is returned to the normal control. After the processing of this step, this routine is once ended.

  According to this routine described above, the start threshold value can be set higher than normal when the bed temperature of the catalytic converter 313 is equal to or lower than a predetermined temperature during EV traveling. As a result, the internal combustion engine 300 cannot be started even when there is a request to start the internal combustion engine 300 with power lower than the start threshold set higher than normal.

  In this routine, when it is determined in step S102 that the bed temperature of the catalytic converter 313 is equal to or lower than the predetermined temperature, the starting threshold value is set higher than normal in step S103. However, the present invention is not limited to this. For example, if the processing in step S102 is eliminated and it is determined in step S101 that the vehicle is running in EV, the starting threshold value may be set higher than normal in step S103. According to this, the internal combustion engine 300 cannot be started in an operation state in which the exhaust state discharged from the internal combustion engine 300 has a low temperature and a low flow rate when the EV is running. The starting threshold value for starting the internal combustion engine 300 indicated by the power required by the engine 300 can be set higher than usual.

In this embodiment, the motor generator 400 is used as the motor of the present invention. Furthermore, when the EV traveling is performed with the internal combustion engine 300 stopped, the motor 500 serves as a drive source. However, the motor of the present invention is not limited to this, and a single motor generator may be used as the motor, or a motor and a generator may be provided separately.

  The hybrid vehicle control device according to the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the scope of the present invention.

1 is a diagram illustrating a schematic configuration of a hybrid vehicle according to a first embodiment. 1 is a diagram illustrating a schematic configuration of an internal combustion engine according to a first embodiment. The figure which shows Example 1 and the relationship between the starting threshold value and the operation control of an internal combustion engine which concern on the past. The figure which shows the operation line of the internal combustion engine which concerns on Example 1 and a normal time. 3 is a flowchart showing a control routine at the time of starting the internal combustion engine according to the first embodiment.

Explanation of symbols

100 Hybrid vehicle 200 ECU
300 internal combustion engine 309 intake passage 310 exhaust passage 311 EGR passage 312 EGR valve 313 catalyst converter 314 catalyst bed temperature sensor 400 motor generator 500 motor 800 battery

Claims (5)

An internal combustion engine as a power source;
A motor that serves as a power source together with the internal combustion engine by the electric energy supplied from the battery and charges the battery by regeneration;
A catalyst disposed in an exhaust passage of the internal combustion engine for purifying exhaust;
Catalyst bed temperature detecting means for detecting the bed temperature of the catalyst;
When only the motor is operating as a power source, the catalyst bed temperature detected by the catalyst bed temperature detecting means is equal to or lower than a predetermined temperature at which the operation of the internal combustion engine is required to warm up the catalyst. In this case, setting means for setting a starting threshold value for starting the internal combustion engine indicated by the power required by the internal combustion engine higher than normal time;
A control apparatus for a hybrid vehicle, comprising: An internal combustion engine as a power source;
A motor that serves as a power source together with the internal combustion engine by the electric energy supplied from the battery and charges the battery by regeneration;
A catalyst disposed in an exhaust passage of the internal combustion engine for purifying exhaust;
When only the motor is operating as a power source, the operating state required for the internal combustion engine is such that the internal combustion engine cannot be started in an operating state where the exhaust gas discharged from the internal combustion engine has a low temperature and a low flow rate. Setting means for setting a starting threshold value for starting the internal combustion engine indicated by the power required by the internal combustion engine higher than normal;
A control apparatus for a hybrid vehicle, comprising: An EGR passage that takes in part of exhaust gas from the exhaust passage of the internal combustion engine as EGR gas and recirculates the EGR gas to the intake passage of the internal combustion engine;
An EGR valve disposed in the EGR passage and controlling the amount of EGR gas;
EGR valve control means for controlling the opening of the EGR valve to the closed side when the internal combustion engine is started by setting the starting threshold value higher than normal by the setting means;
The control apparatus for a hybrid vehicle according to claim 1, comprising:   When the internal combustion engine is started after the start threshold is set higher than normal by the setting means, the battery is charged by regeneration of the motor using a part of the power of the internal combustion engine after the start, The control apparatus for a hybrid vehicle according to any one of claims 1 to 3, further comprising control means for increasing power of the internal combustion engine after starting.   The control means increases a required charge amount for charging the battery by regenerating the motor using a part of the power of the internal combustion engine after starting higher than normal, and charges the battery after starting. The hybrid vehicle control device according to claim 4, wherein the power of the internal combustion engine is increased.

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