JP6500817B2 - Hybrid vehicle - Google Patents

Description

  The present invention relates to a hybrid vehicle, and more particularly to a hybrid vehicle capable of switching between a CD (Charge Depleting) mode and a CS (Charge Sustaining) mode.

  JP 2010-23758 A (patent document 1) comprises an engine, a battery, a motor generating travel driving force based on electric power supplied from the battery, and an electrically heated catalyst installed in an exhaust path of the engine A hybrid vehicle is disclosed (hereinafter, also referred to as "EHC (Electrically Heated Catalyst)"). EHC contains a catalyst inside, and when EHC is energized, the catalyst is warmed up. When the engine is operated with the catalyst warmed up, the engine exhaust is purified.

  The engine starts when the battery state of charge (SOC) drops to a predetermined value. In this hybrid vehicle, in order to complete catalyst warm-up by the time of engine start, the start timing of catalyst warm-up is determined based on the SOC of the battery and the vehicle speed (see Patent Document 1).

Unexamined-Japanese-Patent No. 2010-23758

  In a hybrid vehicle capable of switching between a CD (Charge Depleting) mode and a CS (Charge Sustaining) mode, the start timing of the engine is not necessarily determined only by the SOC and the vehicle speed of the battery. Therefore, even if the catalyst warm-up start timing is determined based only on the battery SOC and vehicle speed as in the technology disclosed in Patent Document 1, it is assumed that catalyst warm-up is completed at engine start-up. There is no limit.

  The present invention has been made to solve such a problem, and an object thereof is to appropriately perform catalyst warm-up in a hybrid vehicle capable of switching between the CD mode and the CS mode.

  A hybrid vehicle according to one aspect of the present invention can switch between the CD mode and the CS mode. A hybrid vehicle includes an electric motor, an internal combustion engine, an electrically heated catalyst, and a controller. The motor generates a traveling drive force. The electrically heated catalyst is provided in an exhaust path of the internal combustion engine, includes a catalyst for purifying the exhaust gas, and receives supply of electric power from the power storage device to heat the catalyst. The control device controls the energized state of the electrically heated catalyst device. When the CD mode is selected, the control device deenergizes the electrically heated catalyst. Further, when the CS mode is selected in a state where warming up of the catalyst is not completed, the control device brings the electrically heated catalyst into the energized state.

  If the CD mode is selected, the possibility of starting the internal combustion engine is low. Therefore, even if catalyst warm-up is performed in this case, power may be wasted. On the other hand, if the CS mode is selected, there is a high possibility that the internal combustion engine will start. Therefore, it is effective to perform catalyst warm-up in this case. In this hybrid vehicle, when the CD mode is selected in a state where the catalyst warm-up is not completed, the electrically heated catalyst is de-energized, and the catalyst warm-up is not completed. Is selected, the electrically heated catalyst is energized. Therefore, according to this hybrid vehicle, the catalyst can be warmed up as needed without wasting power.

  A hybrid vehicle according to another aspect of the present invention can switch between the CD mode and the CS mode. The hybrid vehicle includes a power storage device, an electric motor, an internal combustion engine, an electrically heated catalyst, a power adjustment unit, and a control device. The power storage device can be charged and discharged. The motor receives supply of electric power from the power storage device to generate a traveling driving force. The electrically heated catalyst is provided in an exhaust path of the internal combustion engine, includes a catalyst that purifies the exhaust, and heats the catalyst. The power adjustment unit adjusts the amount of power supplied to the electrically heated catalyst. The control device controls the internal combustion engine and the power adjustment unit. When the catalyst temperature is higher than a predetermined temperature when the CD mode is selected in a state where the catalyst has not been warmed up, the controller reduces the SOC of the power storage device to the first SOC, The power adjustment unit is controlled to supply the first electric power to the electrically heated catalyst, and when the temperature of the catalyst is equal to or lower than a predetermined temperature, when the SOC decreases to a second SOC higher than the first SOC, The power adjustment unit is controlled to supply a second power smaller than the first power to the electrically heated catalyst. Further, the controller supplies the third electric power to the electrically heated catalyst when the temperature of the catalyst is higher than a predetermined temperature when the CS mode is selected in the state where the catalyst has not been warmed up. Control the electric power adjusting unit to control the electric power adjusting unit to supply the fourth electric power smaller than the third electric power to the electrically heated catalyst when the temperature of the catalyst is equal to or lower than the predetermined temperature The internal combustion engine is controlled to warm up the internal combustion engine.

  Under a low temperature environment (when the temperature of the catalyst is equal to or lower than a predetermined temperature), the temperature of the electrically heated catalyst is lowered. Under such circumstances, if the electrically heated catalyst is rapidly heated, the temperature difference between the inner surface of the electrically heated catalyst and the central portion becomes large. As a result, the thermal stress generated inside the electrically heated catalyst is increased, and the electrically heated catalyst may be broken. In this hybrid vehicle, regardless of the CD mode / CS mode, smaller electric power is supplied to the electrically heated catalyst when the catalyst temperature is equal to or lower than the predetermined temperature than when the catalyst temperature is higher than the predetermined temperature. Therefore, an increase in the temperature difference between the inner surface and the central portion of the electrically heated catalyst can be suppressed, and the possibility of breakage of the electrically heated catalyst can be reduced.

  Here, when the catalyst temperature is equal to or lower than the predetermined temperature when the CD mode is selected, the SOC is lowered to a higher SOC than when the catalyst temperature is higher than the predetermined temperature. Power supply is started. Therefore, since the time for which power is supplied to the electrically heated catalyst is extended, catalyst warm-up can be completed before the internal combustion engine is started even if the power supplied to the electrically heated catalyst is small.

  On the other hand, when the catalyst temperature is equal to or lower than the predetermined temperature when the CS mode is selected, the internal combustion engine performs the warm-up operation together with the power supply to the electrically heated catalyst. Therefore, even if the electric power supplied to the electrically heated catalyst is small, catalyst warm-up can be completed before the internal combustion engine is fully started.

  According to the present invention, catalyst warm-up can be appropriately performed in a hybrid vehicle capable of switching between the CD mode and the CS mode.

FIG. 1 is an overall block diagram of a hybrid vehicle according to a first embodiment. It is a figure which shows the circuit structure of 1st and 2nd MG, PCU, a battery, and EHC. It is a figure for demonstrating CD mode and CS mode. It is a flow chart which shows the processing procedure of energization control of EHC. FIG. 17 is a flowchart showing a processing procedure of EHC energization control in the hybrid vehicle according to the second embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference characters and description thereof will not be repeated.

Embodiment 1
[Configuration of hybrid vehicle]
FIG. 1 is an overall block diagram of a hybrid vehicle 1 according to the first embodiment. Hybrid vehicle 1 includes an engine 10, a first MG (Motor Generator) 20, a second MG 30, a power split device 40, a reduction gear 50, a PCU (Power Control Unit) 60, a battery 70, and a drive wheel 80. , ECU (Electronic Control Unit) 200. The hybrid vehicle 1 further includes an exhaust passage 130, an exhaust temperature sensor 2, an EHC 140, a charge port 160, a charger 170, and a CD (Charge Depleting) / CS (Charge Sustaining) switching button 210.

  Engine 10, first MG 20 and second MG 30 are connected via power split device 40. Hybrid vehicle 1 travels by the driving force from at least one of engine 10 and second MG 30.

  The engine 10 is an internal combustion engine that generates a driving force that rotates a crankshaft by combustion energy generated when an air-fuel mixture is burned. Engine 10 is controlled by a control signal from ECU 200. The power generated by engine 10 is divided by power split device 40 into a path transmitted to drive wheel 80 and a path transmitted to first MG 20.

  The first MG 20 and the second MG 30 are motor generators driven by alternating current. The first MG 20 generates power using the power of the engine 10 divided by the power dividing device 40. The power generated by the first MG 20 is supplied to the battery 70 and the second MG 30.

  Second MG 30 generates traveling driving force using at least one of the power supplied from battery 70 and the power generated by first MG 20. Then, the traveling drive force of the second MG 30 is transmitted to the drive wheel 80. When the hybrid vehicle 1 is braked, the second MG 30 is driven by the drive wheels 80, and the second MG 30 operates as a generator. Thus, the second MG 30 functions as a regenerative brake that converts kinetic energy of the hybrid vehicle 1 into electrical energy. The regenerative power generated by the regenerative power generation by the second MG 30 is charged to the battery 70 via the PCU 60. The electric power stored in the battery 70 and the regenerative electric power generated by the first MG 20 and / or the second MG 30 are also supplied to the EHC 140 as needed, as described in detail later.

  The power split device 40 is configured by a planetary gear including a sun gear, a pinion gear, a carrier, and a ring gear. The pinion gear engages with the sun gear and the ring gear. The carrier rotatably supports the pinion gear and is coupled to the crankshaft of the engine 10. The sun gear is coupled to the rotation shaft of the first MG 20. The ring gear is connected to the rotation shaft of the second MG 30 and the reduction gear 50.

  PCU 60 is controlled by a control signal from ECU 200. PCU 60 converts the DC power supplied from battery 70 into AC power capable of driving first MG 20 and second MG 30. The PCU 60 outputs the converted AC power to the first MG 20 and the second MG 30, respectively. Thus, the first MG 20 and the second MG 30 are driven by the power stored in the battery 70. The PCU 60 can also convert AC power generated by the first MG 20 and the second MG 30 into DC power, and charge the battery 70 with the converted DC power.

  Battery 70 is a chargeable and dischargeable direct current power source, and is formed of, for example, a secondary battery such as nickel hydrogen or lithium ion. The output voltage of battery 70 is, for example, a high voltage over 200V. The battery 70 includes a voltage sensor and a current sensor (not shown). The voltage sensor detects a voltage V1 of the battery 70, and the current sensor detects a current I1 input to or output from the battery 70. The detection results of the voltage sensor and the current sensor are output to the ECU 200. Note that, instead of the battery 70, a large capacity capacitor can also be adopted.

  The exhaust passage 130 is a passage for discharging the exhaust gas of the engine 10 to the atmosphere. In the middle of the exhaust passage 130, an EHC 140 is provided. The EHC 140 includes a catalyst and an electric heater for purifying the exhaust gas of the engine 10, and is configured to be able to heat the catalyst by the electric heater. When the EHC 140 and the battery 70 are energized, power is supplied to the electric heater, and the catalyst is heated (warmed up). When the engine 10 operates with the catalyst warmed up, the exhaust gas of the engine 10 is purified. In addition, various known ones can be applied to the EHC 140.

  Further, an exhaust temperature sensor 2 is provided in the middle of the exhaust passage 130. The exhaust temperature sensor 2 detects the temperature of the exhaust gas discharged from the engine 10. Note that various known sensors can be applied to the exhaust temperature sensor 2.

  As described above, hybrid vehicle 1 includes charging port 160 and charger 170 for charging battery 70 with the power supplied from external power supply 310. That is, the hybrid vehicle 1 is a so-called plug-in hybrid vehicle. In addition, charge of the battery 70 by the electric power supplied from the external power supply 310 is also called "external charge" below.

  Charging port 160 is a power interface for receiving power from external power supply 310. At the time of external charging, connector 300 for supplying power from external power supply 310 to the vehicle is connected to charging port 160.

  Charger 170 is electrically connected to charging port 160 and battery 70. Then, the charger 170 converts the power supplied from the external power supply 310 into a power that can charge the battery 70, and charges the battery 70.

  FIG. 2 is a diagram showing a circuit configuration of first MG 20, second MG 30, PCU 60, battery 70, and EHC 140. Referring to FIG. 2, a system main relay (SMR) 71 is provided between PCU 60 and battery 70. SMR 71 is controlled by a control signal from ECU 200, and switches between supply and shutoff of power between battery 70 and PCU 60.

  PCU 60 includes converters 61 and 100 and inverters 62 and 63. Converter 61 is provided between battery 70 and inverters 62 and 63. Converter 61 is controlled by a control signal from ECU 200, and performs voltage conversion between battery 70 and inverters 62 and 63.

  Inverter 62 is provided between converter 61 and first MG 20. Inverter 63 is provided between converter 61 and second MG 30. The inverters 62 and 63 are controlled by a control signal from the ECU 200, convert the DC power voltage-converted by the converter 61 into AC power, and output the AC power to the first MG 20 and the second MG 30, respectively.

  Converter 100 is provided between battery 70 and EHC 140. Converter 100 is controlled by a control signal from ECU 200, and performs voltage conversion between battery 70 and EHC 140. For example, converter 100 can adjust the power supplied to EHC 140 by performing voltage adjustment in accordance with the control signal from ECU 200.

  EHC 140 is connected to converter 100. In EHC 140, the catalyst is heated using the power after battery 70 power is adjusted by converter 100. The EHC 140 switches between the energized state and the non-energized state. Further, the EHC 140 includes a temperature sensor (not shown), and the temperature sensor detects a temperature T1 of a catalyst included in the EHC 140. The detection result of the temperature sensor is output to the ECU 200.

  Again referring to FIG. 1, the CD / CS switching button 210 is a button for switching between the CD mode and the CS mode. Although the details will be described later, basically, when the SOC of the battery 70 decreases, the mode of the hybrid vehicle 1 switches from the CD mode to the CS mode. However, for example, when the CD mode is selected, if the user operates the CD / CS switching button 210, the mode switches from the CD mode to the CS mode regardless of the SOC of the battery 70.

  The ECU 200 incorporates a CPU (Central Processing Unit) and a memory (not shown), and is configured to execute predetermined arithmetic processing based on the information stored in the memory. Although FIG. 1 shows the ECU 200 as one unit, the ECU 200 may be divided into two or more units. ECU 200 selectively applies, for example, the CD mode and the CS mode to control the traveling of the vehicle. Further, ECU 200 estimates the SOC of battery 70 based on detection results (V1 and I1) of the voltage sensor and current sensor of battery 70, for example.

  As a main function of the ECU 200, there is an energization control of the EHC 140. ECU 200 controls the energization state (energized state / non-energized state) of EHC 140 and battery 70. The ECU 200 controls the electrification state of the EHC 140 according to the mode (CD / CS mode) of the hybrid vehicle 1. Hereinafter, the CD mode and the CS mode will be described, and thereafter, energization control of the EHC 140 will be described.

[Description of CD / CS mode]
FIG. 3 is a diagram for explaining the CD mode and the CS mode. Referring to FIG. 3, for example, it is assumed that traveling is started in the CD mode after battery 70 is fully charged by external charging.

  The CD mode is a mode that consumes the SOC, and basically, consumes the power stored in the battery 70 (mainly, the electrical energy by external charging). When traveling in the CD mode, the engine 10 does not operate to maintain the SOC. As a result, although the SOC may temporarily increase due to the regenerated electric power recovered when the vehicle decelerates etc. and the electric power generated due to the operation of the engine 10, as a result, the rate of discharge rather than charging Becomes relatively large, and as a whole, the SOC decreases with the increase of the travel distance.

  The CS mode is a mode in which the SOC is maintained at a predetermined level. As an example, at time t1, when the SOC decreases to a predetermined value SL indicating a decrease in SOC, the CS mode is selected, and the SOC thereafter is controlled within the control range RNG. Specifically, when the SOC reaches the lower limit (engine start threshold) of the control range RNG, the engine 10 operates, and when the SOC reaches the upper limit of the control range RNG, the engine 10 is stopped. Thus, the SOC is controlled within the control range RNG by appropriately repeating the operation and the stop of the engine 10 (intermittent operation). Thus, in the CS mode, the engine 10 operates to maintain the SOC.

  Even in the CD mode, the engine 10 operates if a large travel driving force is required. On the other hand, even in the CS mode, if the SOC rises, the engine 10 is stopped. That is, the CD mode is not limited to the EV travel where the engine 10 is always stopped and travels, and the CS mode is not limited to the HV travel where the engine 10 is always operated and travels. In both the CD mode and the CS mode, EV travel and HV travel are possible.

  Although not shown in particular, when the CD / CS switching button 210 is operated by the user when the CD mode is selected, the mode of the hybrid vehicle 1 changes from the CD mode to the CS mode regardless of the SOC of the battery 70. Switch to In this case, the control range RNG is set with the SOC at the time when the user operates the CD / CS switching button 210 as the control center. Therefore, when the CS mode is selected, the SOC is not always controlled around the predetermined value SL.

[Energization control of EHC in a CD / CS mode compatible vehicle]
Next, energization control of the EHC 140 will be described. The ECU 200 energizes the EHC 140 and the battery 70 in order to warm up the catalyst of the EHC 140. However, if the timing for turning on the EHC 140 is not appropriate, the power used to warm up the catalyst is wasted. For example, when the engine 10 is not used, the exhaust gas is not discharged from the engine 10. In this case, even if the catalyst of the EHC 140 is warmed up, power is wasted. On the other hand, in the situation where the engine 10 is used, if the catalyst is not completely warmed up, the exhaust gas is not sufficiently purified, which is a problem.

  As described above, hybrid vehicle 1 according to the first embodiment can switch between the CD mode and the CS mode. When the CD mode is selected, the possibility of starting the engine 10 is low. In the CD mode, the engine 10 does not operate to maintain the SOC. Therefore, even if the EHC 140 is energized in this case (even if the catalyst is warmed up), the power is likely to be wasted.

  On the other hand, when the CS mode is selected, the engine 10 is likely to start. In the CS mode, the engine 10 operates to maintain the SOC. Therefore, in this case, it is effective to set the EHC 140 to the energized state.

  Further, in the case where the CD / CS switching button 210 is provided as in the hybrid vehicle 1, it is not sufficient to merely put the EHC 140 into the energized state when the SOC of the battery 70 decreases. Even when the SOC is high, when the user operates the CD / CS switching button 210, the CS mode is selected, and the possibility of starting the engine 10 is increased.

  Therefore, in hybrid vehicle 1 according to the first embodiment, when the CD mode is selected, ECU 200 sets EHC 140 in the non-energized state, and the CS mode is selected in the state where the catalyst has not been warmed up. If it does, the EHC 140 is energized. According to this, the catalyst can be warmed up as needed without wasting power.

[Process procedure of EHC energization control]
FIG. 4 is a flowchart showing the processing procedure of energization control of the EHC 140. The process shown in the flowchart is repeatedly executed by the ECU 200 after startup of the vehicle system.

  Referring to FIG. 4, ECU 200 estimates the SOC of battery 70 based on the outputs of the voltage sensor and current sensor (not shown) included in battery 70, and the output of a temperature sensor (not shown) included in EHC 140. The temperature of the catalyst is detected based on (step S100).

  Thereafter, the ECU 200 determines whether the CD mode is selected as the mode of the hybrid vehicle 1 or the CS mode is selected (step S110). If it is determined that the CD mode is selected ("CD mode" in step S110), the EHC 140 is not energized (non-energized state) since the possibility of starting the engine 10 is low (the process is return) Transition.

  On the other hand, if it is determined that the CS mode is selected ("CS mode" in step S110), ECU 200 determines whether the catalyst of EHC 140 is not warmed up based on the temperature of the catalyst detected in step S100. It is determined whether or not (step S120). If it is determined that the catalyst has been warmed up (NO in step S120), the process proceeds to step S150.

  On the other hand, when it is determined that the catalyst is not warmed up (YES in step S120), the possibility of engine 10 starting in the CS mode is high, and therefore, ECU 200 brings EHC 140 into the energized state (step S130).

  Thereafter, the ECU 200 determines whether or not the catalyst warm-up is completed (step S140), and keeps the EHC 140 energized until the catalyst warm-up is completed (NO in step S140).

  If it is determined that warm-up of the catalyst is completed (YES in step S140), ECU 200 determines whether or not engine 10 is in operation (step S150). If it is determined that engine 10 is in operation (YES in step S150), the process proceeds to return. On the other hand, when it is determined that engine 10 is not in operation (NO in step S150), ECU 200 determines whether a start condition of engine 10 is satisfied (step S160). For example, ECU 200 determines whether or not it is necessary to start engine 10 for charging battery 70 because the SOC of battery 70 has decreased to the engine start threshold value.

  If it is determined that the start condition of engine 10 is not satisfied (NO in step S160), the process proceeds to return. On the other hand, when it is determined that the start condition of engine 10 is satisfied, ECU 200 controls engine 10 so that engine 10 is started, and places EHC 140 in the energized state (step S170).

  The reason why the ECU 200 executes the start control of the engine 10 and puts the EHC 140 in the energized state will be described. For example, in a low temperature environment, when the engine 10 is started with the catalyst warm-up completed, exhaust gas having a temperature lower than that of the warm-up catalyst flows into the catalyst and the temperature of the catalyst decreases. As a result, the warm-up catalyst may be deactivated. Even when exhaust gas at a temperature lower than the catalyst flows into the catalyst by bringing the EHC 140 into an energized state when starting the engine 10 while the catalyst warm-up is completed, the catalyst is being heated Therefore, it is possible to prevent the deactivation of the warmed catalyst.

  Thereafter, the ECU 200 determines whether the temperature of the exhaust gas discharged from the engine 10 has become equal to or higher than the predetermined temperature Tth1 based on the output (temperature T2) of the exhaust temperature sensor 2 (step S180). The predetermined temperature Tth1 is a temperature at which the catalyst does not deactivate even if the inflow of exhaust gas at this temperature occurs. If it is determined that the temperature of the exhaust gas is less than the predetermined temperature Tth1 (NO in step S180), the ECU 200 continues the energization of the EHC 140 until the temperature of the exhaust gas becomes equal to or higher than the predetermined temperature Tth1.

  On the other hand, when it is determined that the temperature of the exhaust gas is equal to or higher than predetermined temperature Tth1 (YES in step S180), ECU 200 controls EHC 140 so that the energization state of EHC 140 is shut off (to become the non-energization state). (Step S190). Thereafter, processing shifts to return.

  As described above, in hybrid vehicle 1 according to the first embodiment, when the CD mode is selected, ECU 200 puts EHC 140 in the non-energized state, and the catalyst warm-up is not completed in the CS mode. Is selected, the EHC 140 is energized. According to this, the catalyst can be warmed up as needed without wasting power.

Second Embodiment
Referring again to FIGS. 1 and 2, in hybrid vehicle 1 according to the first embodiment, the control content of EHC 140 is changed according to the selected mode (CD / CS mode). Hybrid vehicle 1A according to the second embodiment is characterized by the control of energization of EHC 140 particularly in a low temperature environment, and depending on the selected mode (CD / CS mode) and whether it is in a low temperature environment or not. The control content of is changed.

  Unlike hybrid vehicle 1 according to the first embodiment, hybrid vehicle 1A includes an ECU 200A. The other configuration is similar to that of hybrid vehicle 1 according to the first embodiment.

  Under a low temperature environment, the temperature of the EHC 140 is decreasing. Under such circumstances, when the EHC 140 is rapidly heated, the temperature difference between the inner surface of the EHC 140 substrate and the central portion of the substrate becomes large. As a result, the thermal stress generated inside the EHC 140 substrate increases, and the EHC 140 may be broken.

  Therefore, in hybrid vehicle 1A according to the second embodiment, regardless of the CD mode / CS mode, when the catalyst temperature is equal to or lower than the predetermined temperature, ECU 200A causes EHC 140 to be higher than when the catalyst temperature is higher than the predetermined temperature. The converter 100 is controlled to supply small power. As a result, the temperature difference between the inner surface of the base of the EHC 140 and the central portion of the base is suppressed from being increased, and the possibility of breakage of the EHC 140 can be reduced.

  However, merely reducing the power supplied to the EHC 140 may cause the catalyst warm-up not to be completed by the time the engine 10 is started.

  Therefore, in hybrid vehicle 1A according to the second embodiment, ECU 200A has a SOC higher than that when the catalyst temperature exceeds the predetermined temperature when the catalyst temperature is equal to or lower than the predetermined temperature when the CD mode is selected. When the SOC of the battery 70 decreases to the maximum, the EHC 140 is controlled so that the EHC 140 is energized. As a result, the time from the start of energization of the EHC 140 to switching to the CS mode becomes long, so catalyst warm-up can be completed before the engine 10 is started even if the power supplied to the EHC 140 is small.

  Further, when the catalyst temperature is equal to or lower than the predetermined temperature when the CS mode is selected, the ECU 200A controls the engine 10 such that the EHC 140 is energized and the engine 10 performs the warm-up operation. As a result, even if the power supplied to the EHC 140 is small, the catalyst warm-up can be completed before the engine 10 is fully started by using the warm-up by the exhaust of the engine 10 in combination.

[Process procedure of EHC energization control]
FIG. 5 is a flow chart showing a procedure of energization control of EHC 140 in hybrid vehicle 1A according to the second embodiment. The process shown in the flowchart is repeatedly executed by the ECU 200A after startup of the vehicle system.

  Referring to FIG. 5, ECU 200A estimates the SOC of battery 70 based on the outputs of the voltage sensor and current sensor (not shown) included in battery 70, and also outputs the output of a temperature sensor (not shown) included in EHC 140. The temperature of the catalyst is detected based on (step S200).

  After that, the ECU 200A determines whether the catalyst of the EHC 140 is not warmed up based on the temperature of the catalyst detected in step S200 (step S210). If it is determined that the catalyst has been warmed up (NO in step S210), the process proceeds to return.

  On the other hand, when it is determined that the catalyst is not warmed up (YES in step S210), ECU 200A determines whether CD mode is selected or CS mode is selected as the mode of hybrid vehicle 1A (step S220).

  If it is determined that the CD mode is selected ("CD mode" in step S220), the ECU 200A determines whether the catalyst temperature of the EHC 140 is equal to or lower than a predetermined temperature Tth2 (step S230). If it is determined that the catalyst temperature is higher than predetermined temperature Tth2 (NO in step S230), ECU 200A determines whether or not the SOC of battery 70 is less than or equal to predetermined value S2 (<predetermined value S1 (described later)) Step S240). If it is determined that the SOC is higher than predetermined value S2 (NO in step S240), the process proceeds to return. On the other hand, if it is determined that the SOC is less than or equal to the predetermined value S2 (YES in step S240), the possibility of shifting to the CS mode and starting the engine 10 in a short time is high. The converter 100 is controlled to supply power (step S250).

  If it is determined in step S230 that the catalyst temperature is less than or equal to the predetermined value Tth2 (YES in step S230), the ECU 200A determines whether the SOC of the battery 70 is less than or equal to the predetermined value S1 (> predetermined value S2). (Step S260). If it is determined that the SOC is higher than predetermined value S1 (NO in step S260), the process proceeds to return. On the other hand, when it is determined that the SOC is equal to or less than predetermined value S1 (YES in step S260), ECU 200A controls converter 100 to supply EHC 140 with the second power smaller than the first power (step S270). The second power (<first power) is supplied to EHC 140 because EHC 140 may be damaged when the first power is supplied to EHC 140 when the catalyst temperature is low (in a low temperature environment) Because it is expensive. Even if the power supplied to the EHC 140 is the second power, the EHC 140 is in the energized state when the SOC decreases to the predetermined value S1 (> the predetermined value S2), so the catalyst temperature is the predetermined value The time from the start of energization of the EHC 140 to switching to the CS mode is longer than when Th2 is higher than Tth2, and catalyst warm-up can be completed before the engine 10 is started.

  After steps S250 and S270, the ECU 200A determines whether catalyst warm-up is completed based on the output of a temperature sensor (not shown) included in the EHC 140 (step S280). If it is determined that the catalyst warm-up has not been completed (NO in step S280), the ECU 200A continues the energization of the EHC 140 until the catalyst warm-up is completed. On the other hand, when it is determined that the catalyst warm-up is completed (YES in step S280), ECU 200A controls EHC 140 so that the energization state of EHC 140 is cut off (to become the non-energization state) (step S285). ). Thereafter, processing shifts to return.

  If it is determined in step S220 that the CS mode is selected ("CS mode" in step S220), the ECU 200A determines whether the catalyst temperature of the EHC 140 is less than or equal to a predetermined temperature Tth2 (step S290). If it is determined that the catalyst temperature is higher than predetermined temperature Tth2 (NO in step S290), ECU 200A controls converter 100 to supply EHC 140 with the third power (step S300).

  On the other hand, when it is determined that the catalyst temperature is equal to or lower than predetermined temperature Tth2 (YES in step S290), ECU 200A supplies fourth power smaller than the third power to EHC 140 in order to prevent damage to EHC 140. The converter 100 is controlled to control the engine 10 so that the engine 10 starts the warm-up operation (step S310). Even if the power supplied to the EHC 140 is the fourth power (<third power), the engine 10 performs the warm-up operation, so catalyst warm-up can be completed before the engine 10 is fully started.

  After steps S300 and S310, the ECU 200A determines whether catalyst warm-up is completed based on the output of a temperature sensor (not shown) included in the EHC 140 (step S320). If it is determined that the catalyst warm-up is not completed (NO in step S320), the ECU 200A continues the energization state of the EHC 140 until the catalyst warm-up is completed. On the other hand, when it is determined that the catalyst warm-up is completed (YES in step S320), ECU 200A controls EHC 140 so that the energization state of EHC 140 is cut off (to become the non-energization state) (step S325). ). Thereafter, processing shifts to return.

  As described above, in hybrid vehicle 1A according to the second embodiment, regardless of the CD mode / CS mode, when the catalyst temperature is equal to or lower than the predetermined temperature, ECU 200A is more than when the catalyst temperature is higher than the predetermined temperature. , Control the converter 100 to supply small power to the EHC 140. Then, when the catalyst temperature is equal to or lower than the predetermined temperature when the CD mode is selected, the ECU 200A is in a stage where the SOC of the battery 70 decreases to a higher SOC than when the catalyst temperature exceeds the predetermined temperature, The EHC 140 is controlled so that the EHC 140 is energized. On the other hand, when the catalyst temperature is equal to or lower than the predetermined temperature when the CS mode is selected, the ECU 200A controls the engine 10 such that the EHC 140 is energized and the engine 10 performs the warm-up operation. Thus, catalyst warm-up can be completed before the engine 10 is started while preventing damage to the EHC 140 due to the temperature difference between the inner surface of the EHC 140 and the central portion becoming large at low temperatures.

(Other embodiments)
As described above, Embodiments 1 and 2 have been described as the embodiments of the present invention. However, the present invention is not necessarily limited to the first and second embodiments. Here, an example of another embodiment will be described.

  In the first embodiment, when the CD mode is selected, the EHC 140 is in the non-energized state, and when the EHC 140 is not warmed up when transitioning from the CD mode to the CS mode, the EHC 140 is in the energized state. It was decided to be. However, the timing at which the EHC 140 is switched to the energized state is not limited to this. For example, when the EHC 140 is not warmed up when the SOC of the battery 70 decreases to a threshold value higher than the predetermined value SL (FIG. 3), the ECU 200 may set the EHC 140 to the energized state. In addition, for example, when it is predicted that the mode of the vehicle changes from the CD mode to the CS mode based on the SOC of the battery 70 and the change amount of the SOC, the ECU 200 may cause the EHC 140 to be in the energized state. Thereby, the warm-up of the EHC 140 can be started before the transition to the CS mode.

  Further, in the first and second embodiments, the EHC 140 receives the supply of power from the battery 70. However, the power supply of the EHC 140 is not limited to the battery 70. For example, EHC 140 may be configured to receive power supply from an accessory battery or the like other than battery 70.

  Further, in the first and second embodiments, the ECUs 200 and 200 </ b> A switch the energization state of the EHC 140 by controlling the EHC 140. However, in order to switch the energization state of the EHC 140, the target to be controlled is not limited to the EHC 140. For example, ECU 200 and 200A may be configured to switch the energization state of EHC 140 by controlling converter 100.

  In Embodiments 1 and 2, hybrid vehicles 1 and 1A are plug-in hybrid vehicles. However, hybrid vehicles 1 and 1A are not limited to plug-in hybrid vehicles. For example, hybrid vehicle 1, 1 </ b> A may be a hybrid vehicle that does not include charging port 160 and charger 170.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is indicated not by the above description but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

  DESCRIPTION OF SYMBOLS 1 Hybrid vehicle, 2 Exhaust temperature sensor, 10 engines, 20 1st MG, 30 2nd MG, 40 power split device, 50 reduction gear, 60 PCU, 61, 100 converter, 62, 63 inverter, 70 battery, 71 SMR, 80 drive Wheel, 130 exhaust passage, 140 EHC, 160 charging port, 170 charger, 200 ECU, 210 CD / CS switching button, 300 connector, 310 external power supply.

Claims (1)

A hybrid vehicle capable of switching between a CD (ChargeDepleting) mode and a CS (ChargeSustaining) mode,
An electric motor that generates a traveling drive force,
An internal combustion engine,
An electrically heated catalyst provided in an exhaust path of the internal combustion engine and including a catalyst that purifies exhaust and that receives power supply to heat the catalyst;
And a controller for controlling the energization state of the electrically heated catalyst.
The controller is
When the CD mode is selected, the electrically heated catalyst is de-energized,
The hybrid vehicle, wherein the electrically heated catalyst is energized when the CS mode is selected in a state where warm-up of the catalyst is not completed.

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