JP2012240485A - Control device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration of performance at the engine startup of a vehicle provided with an engine, an EHC, and a rotating electrical machine capable of generating cranking torque by generating power.SOLUTION: The vehicle is provided with the engine, the EHC, a first MG capable of generating cranking torque of the engine by generating power, and a battery. ECU 200 generates the cranking torque by generating power in the first MG according to a vehicle speed V when the activation of engine is required during EV driving (210, 220). ECU 200 reduces the acceptable power value Win of the battery to a limit value W0 which is lower than a reference value W1 when the temperature of the battery is at a prescribed temperature or higher (230). ECU 200 energizes EHC when the activating of engine is required during EV driving, and if the acceptable power value Win is reduced to the limit value W0 and the vehicle speed V is a threshold speed V0 or over (240).

Description

  The present invention relates to control of a vehicle equipped with an electrically heated catalyst (hereinafter also referred to as “EHC”) that purifies engine exhaust.

  A vehicle equipped with an engine is generally provided with a catalyst that purifies the exhaust gas of the engine. If the catalyst does not reach the activation temperature, the exhaust cannot be sufficiently purified. Therefore, conventionally, an EHC configured such that the catalyst can be electrically heated by an electric heater or the like has been proposed.

  Japanese Patent Laid-Open No. 2008-239077 (Patent Document 1) discloses that in a hybrid vehicle including an engine, an EHC, and a motor, when the engine is started while the engine is running while the engine is stopped and the vehicle is driven by the power of the motor. Is estimated to be lower than a predetermined temperature, EHC is energized for a predetermined time to heat the EHC, and a technique for starting the engine after the heating of the EHC is disclosed.

JP 2008-239077 A JP 2009-35236 A

  By the way, when starting the engine, it is necessary to apply cranking torque to the engine using a rotating electrical machine or the like. When the cranking torque is generated by the power generation of the rotating electrical machine, the fuel consumption can be improved by storing the generated power in an in-vehicle battery or the like. However, when the acceptable power of the battery is reduced as the temperature of the battery rises, the generated electric power of the rotating electric machine at the time of cranking may not be accepted by the battery.

  The technology of Patent Document 1 considers the EHC temperature when deciding whether or not to energize the EHC. However, no consideration is given to the electric power generated by the rotating electrical machine or the battery acceptable power during cranking. Not. Therefore, even when the generated power of the rotating electrical machine at the time of cranking exceeds the acceptable power of the battery, it is assumed that the EHC is not energized and the surplus power cannot be consumed by the EHC. Therefore, it is necessary to suppress the electric power generated by the rotating electrical machine at the time of cranking (that is, cranking torque), and there is a concern that the performance at the time of starting the engine deteriorates.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide an engine, an EHC (electrically heatable catalyst device), and torque for cranking the engine by generating electricity. In a vehicle provided with a rotating electrical machine that can be generated, deterioration of engine startability is suppressed.

  A control device according to the present invention includes an engine, an electrically heatable catalyst device that purifies the exhaust of the engine, a rotating electrical machine that can generate torque for generating engine cranking by generating power, and the rotating electrical machine. A vehicle including a power storage device capable of transmitting and receiving electric power is controlled. The control device includes a switching device that switches an electrical connection state between the power storage device, the rotating electrical machine, and the catalyst device, and an energization control unit that controls energization of the catalyst device by controlling the switching device. The energization control unit electrically connects the catalyst device and the rotating electrical machine when cranking accompanied by power generation of the rotating electrical machine is performed and the acceptable power value of the power storage device is reduced to a value lower than the reference value. Connect and energize the catalytic device.

  Preferably, the control device further includes an engine start unit that performs cranking by generating electric power according to the vehicle speed with the rotating electric machine when the engine is started while the vehicle is running with the engine stopped. When cranking is performed while the vehicle is running with the engine stopped, the energization control unit reduces the catalyst when the acceptable power value decreases to a value lower than the reference value and the vehicle speed is equal to or higher than the threshold vehicle speed. Start energization of the device.

  Preferably, the threshold vehicle speed is set to a vehicle speed equal to or lower than an acceptable power value after the generated electric power of the rotating electrical machine at the time of cranking falls below a reference value.

  Preferably, the engine starting unit starts the engine at least when the vehicle speed exceeds the upper limit vehicle speed. The upper limit vehicle speed is a fixed value higher than the threshold vehicle speed.

  Preferably, the energization control unit is configured to be in an area where the power generation of the rotating electrical machine during cranking is not required when the start of the engine is completed after the start of energization of the catalyst apparatus, or when the energization time of the catalyst apparatus exceeds a predetermined time. When the rotational speed of the rotating electrical machine is included, energization of the catalyst device is stopped in at least one of the cases.

  Preferably, the vehicle is a hybrid vehicle including an electric motor that generates a vehicle driving force together with an engine.

  According to the present invention, in a vehicle including an engine, an EHC (electrically heatable catalyst device), and a rotating electrical machine capable of generating torque for cranking the engine by generating electricity, the performance at the time of engine start is achieved. Deterioration can be suppressed.

1 is an overall block diagram of a vehicle. An alignment chart during EV traveling is shown. It is a functional block diagram of ECU. It is a figure which shows the correspondence of the vehicle speed V and cranking electric power generation. It is a flowchart which shows the process sequence of ECU. It is a figure which shows an example of the change aspect of the temperature Tehc of EHC.

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

  FIG. 1 is an overall block diagram of a vehicle 1 according to an embodiment of the present invention. The vehicle 1 includes an engine 10, a motor generator (hereinafter referred to as “MG”) 20, a power split device 40, a speed reducer 50, and a power control unit (hereinafter referred to as “PCU”) 60. , A battery 70, a drive wheel 80, and an electronic control unit (Electronic Control Unit, hereinafter referred to as “ECU”) 200.

  The engine 10 is an engine that generates a driving force for rotating a crankshaft by combustion energy generated when an air-fuel mixture sucked into a combustion chamber is combusted. The ignition timing, fuel injection amount, intake air amount, and the like of the engine 10 are controlled in accordance with a control signal from the ECU 200.

  The MG 20 includes a first MG 21 and a second MG 22. First MG 21 and second MG 22 are AC motors, for example, three-phase AC synchronous motors. In the following description, when it is not necessary to distinguish between the first MG 21 and the second MG 22, they are described as MG 20 without distinguishing them.

  The vehicle 1 is a hybrid vehicle that travels by driving force output from at least one of the engine 10 and the second MG 21. The driving force generated by the engine 10 is divided into two paths by the power split device 40. That is, one is a path transmitted to the drive wheel 80 via the speed reducer 50, and the other is a path transmitted to the first MG 21.

  Power split device 40 includes 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 supports the pinion gear so as to be capable of rotating, and is connected to the crankshaft of the engine 10. The sun gear is connected to the rotation shaft of the first MG 21. The ring gear is connected to the rotation shaft of second MG 22 and reduction gear 50. As described above, the engine 10, the first MG 21 and the second MG 21 are connected via the power split device 40 including the planetary gears, so that the engine rotational speed Ne, the first MG rotational speed Nm1, and the second MG rotational speed Nm2 are collinear. In FIG. 2 (see FIG. 2 described later).

  PCU 60 and battery 70 are connected by a positive line PL1 and a negative line GL1. The PCU 60 operates in response to a control signal from the ECU 200 and controls power supplied from the battery 70 to the MG 20 or power supplied from the MG 20 to the battery 70. Battery 70 stores electric power for driving MG 20. The battery 70 typically includes a direct current secondary battery such as nickel metal hydride or lithium ion. The output voltage of the battery 70 is about 200 volts, for example. Instead of the battery 70, a large-capacity capacitor may be used.

  Exhaust gas discharged from the engine 10 is discharged to the atmosphere through an exhaust passage 130 provided below the floor of the vehicle 1. The exhaust passage 130 extends from the engine 10 to the rear end of the vehicle 1.

  In the middle of the exhaust passage 130, an EHC (electrically heated catalyst) 140 is provided. The EHC 140 includes a catalyst for purifying exhaust gas and a heater configured to be able to electrically heat the catalyst. Various known configurations can be applied to the EHC 140.

  PCU 60 and EHC 140 are connected by a positive line PL2 and a negative line GL2. The EHC 140 is supplied with power from the battery 70 and power generated by the MG 20 via the PCU 60. EHC power supply 100 is provided for positive electrode line PL2 and negative electrode line GL2. The connection relationship between the battery 70 and the EHC 140 is not limited to that shown in FIG.

  The EHC power supply 100 includes a relay inside, and switches an electrical connection state between the EHC 140 and the PCU 60 based on a control signal from the ECU 200. When the relay in the EHC power supply 100 is closed, the EHC 140 and the PCU 60 are connected, and the heater in the EHC 140 is energized (hereinafter also referred to as “EHC energization”). By this EHC energization, the catalyst in the EHC 140 is warmed up. When the relay inside the EHC power supply 100 is opened, the connection between the EHC 140 and the PCU 60 is cut off, and EHC energization is stopped. Thus, the ECU 200 controls the EHC power supply 100 to control the energization amount of the heater in the EHC 140.

  Further, the vehicle 1 includes a monitoring unit 151, a current sensor 152, a voltage sensor 153, a rotation speed sensor 154, resolvers 155 and 156, a vehicle speed sensor 157, an accelerator pedal position sensor 158, and an air conditioning sensor 159.

  The monitoring unit 151 monitors the state of the battery 70 (battery current Ib, battery voltage Vb, battery temperature Tb, etc.). Current sensor 152 detects current Iehc flowing through EHC 140. The voltage sensor 153 detects the voltage Vehc applied to the EHC 140. The rotational speed sensor 154 detects the engine rotational speed Ne. Resolvers 155 and 156 detect rotation speed Nm1 of first MG21 and rotation speed Nm2 of second MG22, respectively. The vehicle speed sensor 157 detects the vehicle speed V. The accelerator pedal position sensor 158 detects the accelerator pedal operation amount A by the user. The air conditioning sensor 159 detects the operating state of the air conditioner. These units and sensor detection results are input to the ECU 200.

  The ECU 200 has a CPU (Central Processing Unit) and a memory (not shown), executes predetermined arithmetic processing based on the map and program stored in the memory and the detection result of each sensor, and determines the result of the arithmetic processing. Each device is controlled so that the vehicle 1 is in a desired state.

  The ECU 200 sets an acceptable power value Win (unit: watts) of the battery 70 in accordance with the battery temperature Tb, and controls the actual received power of the battery 70 so as not to exceed the acceptable power value Win. For example, ECU 200 sets acceptable power value Win to reference value W1 (or may be a value equal to or higher than reference value W1) during normal times when battery temperature Tb is lower than a predetermined temperature. On the other hand, when the battery temperature Tb is higher than the predetermined temperature, the ECU 200 reduces the acceptable power value Win to the limit value W0 lower than the reference value W1 to limit the actual received power of the battery 70 from the normal time. . Thereby, deterioration of the battery 70 is suppressed.

  ECU 200 controls engine 10, first MG 21, and second MG 22 so that vehicle 1 travels in any one of the EV mode, the start mode, and the engine mode. The EV mode is a control mode in which the engine 10 is stopped and the vehicle 1 is driven by the power of the second MG 22. The engine mode is a control mode in which the vehicle 10 is driven by the power of both the engine 10 and the second MG 22 by operating the engine 10. The start mode is a control mode for starting the engine 10 during traveling in the EV mode and shifting from the EV mode to the engine mode.

  FIG. 2 shows an alignment chart during forward traveling in the EV mode (hereinafter also simply referred to as “EV traveling”). As described above, the engine rotational speed Ne, the first MG rotational speed Nm1, and the second MG rotational speed Nm2 are connected by a straight line in the alignment chart. Since second MG 30 rotates in synchronization with drive wheel 80, second MG rotation speed Nm2 is a value corresponding to vehicle speed V (a value directly proportional to vehicle speed V).

  In the EV mode, the engine 10 is stopped and the engine rotation speed Ne is maintained at substantially zero. During EV travel, since Nm2> 0, the first MG 21 rotates in the negative direction (Nm1 <0) due to the relationship in the nomograph. As the vehicle speed V increases, the first MG rotation speed Nm1 increases in the negative direction.

  When starting the engine 10 during EV traveling, the ECU 200 shifts the control mode from the EV mode to the start mode. In the start mode, the ECU 200 causes the first MG 21 to generate a cranking torque in the positive direction to increase the engine rotation speed Ne. The ECU 200 starts ignition control of the engine 10 when the engine rotation speed Ne increases to a predetermined speed. When combustion by this ignition control (so-called first explosion) is performed, the start of the engine 10 is completed. When the start of the engine 10 is completed, the ECU 200 shifts the control mode from the start mode to the engine mode.

  By the way, as described above, during EV traveling, the first MG 21 rotates in the negative direction due to the relationship in the nomograph, and as the vehicle speed V increases, the first MG rotational speed Nm1 increases in the negative direction. In order to generate cranking torque from the first MG 21 in such a state, it is necessary to generate electric power according to the vehicle speed V at the first MG 21.

  Therefore, EUC 200 causes first MG 21 to generate electric power according to vehicle speed V when cranking torque is generated from first MG 21 during EV traveling. Hereinafter, the power generated by the first MG 21 when cranking during EV traveling is also simply referred to as “cranking generated power”.

  The cranking generated power (AC power) is converted into DC power by the PCU 60 and supplied to the battery 70. Therefore, if the cranking generated power exceeds the reference value W1 of the acceptable power value Win of the battery 70, a part of the cranking generated power cannot be received by the battery 70. Therefore, ECU 200 presets a vehicle speed upper limit during EV travel (hereinafter simply referred to as “upper limit vehicle speed Vmax”), and indicates that vehicle speed V has reached upper limit vehicle speed Vmax during EV travel from EV mode to start mode. One of the transition conditions. The upper limit vehicle speed Vmax is set to a vehicle speed V1 slightly lower than the vehicle speed at which the cranking generated power reaches the reference value W1 of the acceptable power value Win of the battery 70.

  However, when the battery temperature Tb is higher than the predetermined temperature, the acceptable power value Win of the battery 70 is lowered to the limit value W0 lower than the reference value W1 as described above. As a result, there is a concern that the battery 70 cannot accept a part of the cranking generated power.

  As a countermeasure for this problem, conventionally, the upper limit vehicle speed Vmax is changed from the vehicle speed V1 to the vehicle speed V0 so that the cranking generated power becomes less than the limit value W0 in accordance with the reduction of the acceptable power value Win to the limit value W0. (<V1) (see the broken line in FIG. 2). However, with this conventional measure, the vehicle speed range in which EV traveling is possible becomes narrow, and the fuel consumption deteriorates. Further, since the magnitude of the cranking torque itself is also reduced, the time until the engine 10 is completely started (the time until the engine rotational speed Ne increases to a predetermined speed) is increased, and drivability (engine startability) is improved. It was getting worse.

  Therefore, ECU 200 according to the present embodiment reduces acceptable power value Win to limit value W0 lower than reference value W1 when cranking torque is generated during EV travel (that is, when first MG 21 generates power). When the power is off, the relay inside the EHC power supply 100 is closed and the EHC is energized. As a result, even if the acceptable power value Win falls to the limit value W0, the EHC 140 can consume the amount exceeding the limit value W0 of the cranking generated power (the surplus power that cannot be received by the battery 70). The upper limit vehicle speed Vmax can be maintained at the vehicle speed V1. Therefore, it is possible to suppress the deterioration of fuel efficiency and the deterioration of engine startability as compared with the case where the upper limit vehicle speed Vmax is reduced. This is the most characteristic point of the present invention.

  FIG. 3 is a functional block diagram of ECU 200. Each functional block shown in FIG. 3 may be realized by hardware or software.

  ECU 200 includes an engine start request determination unit 210, a mode switching unit 220, a Win limiting unit 230, and an EHC energization control unit 240.

  Engine start request determination unit 210 determines the presence or absence of an engine start request based on accelerator pedal operation amount A, vehicle speed V, battery state SOC of battery 70, and the like. This determination is performed based on various criteria. For example, the engine start request determination unit 210 calculates the user request driving force according to the accelerator pedal operation amount A and the vehicle speed V. If the user request driving force exceeds a predetermined value, the power of the engine 10 is required. It is determined that there is an engine start request. Further, engine start request determination unit 210 determines that it is necessary to charge battery 70 with the electric power generated by first MG 21 using the power of engine 10 when storage state SOC of battery 70 is less than a predetermined value. Determine if there is a request. The engine start request determination unit 210 also determines that there is an engine start request because it is necessary to start the engine 10 even when the vehicle speed V reaches the above-described upper limit vehicle speed Vmax during EV traveling. Here, the upper limit vehicle speed Vmax is fixed at the vehicle speed V1 described above (a vehicle speed that is slightly lower than the vehicle speed at which the cranking generated power reaches the reference value W1 of the acceptable power value Win of the battery 70). That is, even if the acceptable power value Win of the battery 70 is reduced to the limit value W0, the upper limit vehicle speed Vmax is not reduced, and the upper limit vehicle speed Vmax is maintained at the vehicle speed V1.

  In addition, the presence / absence of an engine start request may be determined according to the operating state of the air conditioner (the output of the air conditioning sensor 159), various diagnostics, and the like.

  The mode switching unit 220 switches the control mode to any one of the EV mode, the start mode, and the engine mode. The mode switching unit 220 continues the EV mode when there is no engine start request during the EV mode. When there is an engine start request during the EV mode, the mode switching unit 220 switches the control mode from the EV mode to the start mode. At this time, when the vehicle is traveling in the EV mode, the mode switching unit 220 causes the first MG 21 to generate electric power corresponding to the vehicle speed V and cause the first MG 21 to generate forward cranking torque.

  When the start of the engine 10 is completed in the start mode, the mode switching unit 220 switches the control mode from the start mode to the engine mode. At this time, the mode switching unit 220 stops cranking (power generation of the first MG 21), and causes the vehicle 1 to travel with the power of both the engine 10 and the second MG 22. The mode switching unit 220 continues the engine mode when there is an engine start request during the engine mode, and switches the control mode from the engine mode to the EV mode and stops the engine 10 when there is no engine start request. .

  Win limiting unit 230 sets acceptable power value Win of battery 70 in accordance with battery temperature Tb, and controls the actual received power of battery 70 so as not to exceed acceptable power value Win. Win limiting unit 230 sets acceptable power value Win to reference value W1 (or may be a value equal to or higher than reference value W1) at the normal time when battery temperature Tb is lower than a predetermined temperature. On the other hand, when the battery temperature Tb is higher than the predetermined temperature, the Win limiting unit 230 reduces the acceptable power value Win to a limit value W0 lower than the reference value W1.

  The EHC energization control unit 240 controls EHC energization in accordance with the current control mode, presence / absence of an engine start request, acceptable power value Win, vehicle speed V, and the like. Specifically, when there is an engine start request during EV traveling, the EHC energization control unit 240 decreases the acceptable power value Win to the limit value W0 lower than the reference value W1, and the vehicle speed V is When the threshold vehicle speed is V0 or higher, the relay inside the EHC power supply 100 is closed and the EHC is energized. Here, the threshold vehicle speed V0 is set to be equal to or lower than the vehicle speed at which the cranking generated power reaches the limit value W0. Therefore, the threshold vehicle speed V0 is a value lower than the upper limit vehicle speed Vmax (in other words, the upper limit vehicle speed Vmax is a value higher than the threshold vehicle speed V0).

  FIG. 4 is a diagram illustrating a correspondence relationship between the vehicle speed V and the cranking generated power. During EV traveling, as shown in FIG. 4, the cranking generated power increases as the vehicle speed V increases.

  When the acceptable power value Win of the battery 70 is the reference value W1, if cranking is performed in a region where the vehicle speed V is less than the vehicle speed V1 (= the upper limit vehicle speed Vmax), the cranking generated power is the acceptable power value Win of the battery 70. Therefore, the cranking generated power can be received by the battery 70.

  However, when the acceptable power value Win of the battery 70 is reduced from the reference value W1 to the limit value W0, if the vehicle speed V exceeds the threshold vehicle speed V0 corresponding to the limit value W0, The power α exceeding the limit value W0 cannot be accepted by the battery 70. The power α exceeding the limit value W0 becomes surplus power.

  Therefore, when the ECU 200 performs cranking during EV traveling, the acceptable power value Win of the battery 70 decreases from the reference value W1 to the limit value W0, and the vehicle speed V is equal to or higher than a threshold vehicle speed V0 corresponding to the limit value W0. In such a case, surplus power α is consumed by the EHC 140 by conducting EHC energization.

  FIG. 5 is a flowchart showing a processing procedure of the ECU 200 for realizing the above-described functions. This flowchart is repeatedly executed at a predetermined cycle while the vehicle 1 is traveling.

  In step (hereinafter, step is abbreviated as “S”) 10, ECU 200 determines whether or not the control mode is the EV mode.

  If it is determined in S10 that the control mode is the EV mode (YES in S10), ECU 200 determines in S20 whether there is an engine start request. When there is no engine start request (NO in S20), ECU 200 continues the EV mode.

  If there is an engine start request (YES in S20), ECU 200 determines in S40 whether acceptable power value Win of battery 70 is reduced from reference value W1 to limit value W0, and in S41, vehicle speed V It is determined whether the vehicle speed is V0 or higher.

  When acceptable power value Win is reduced to limit value W0 and vehicle speed V is equal to or higher than threshold vehicle speed V0 (YES in S40 and YES in S41), ECU 200 starts EHC energization in S42. Thereafter, ECU 200 switches the control mode from the EV mode to the start mode in S43. By switching to the start mode, power generation (applying cranking torque) of the first MG 21 is started.

  On the other hand, when acceptable power value Win is not reduced to limit value W0 (NO in S40), or when vehicle speed V is lower than threshold vehicle speed V0 (NO in S41), ECU 200 performs the process of S42 ( Without performing the EHC energization start process), the process proceeds to S43, and the control mode is switched from the EV mode to the start mode.

  When it is determined in S10 that the control mode is not the EV mode (NO in S10), ECU 200 determines in S50 whether or not the control mode is the start mode.

  If it is determined in S50 that the control mode is the start mode (YES in S50), ECU 200 determines whether or not engine 10 has been started in S60 (engine speed Ne is equal to or higher than a predetermined speed). Determine whether.

  If starting of engine 10 has not been completed (NO in S60), ECU 200 continues the start mode in S70 and continues the power generation (applying cranking torque) of first MG 21. Thereafter, ECU 200 determines whether or not EHC is energized in S71. If EHC is not energized (NO in S71), ECU 200 ends the process.

  When EHC is being energized (YES in S71), ECU 200 determines in S72 whether EHC energization time T exceeds predetermined time T0, and in S73, first MG rotation speed Nm1 is a predetermined value N0 (for example, N0). = 0 rpm) is determined.

  If EHC energization time T does not exceed predetermined time T0 (NO in S72) and first MG rotation speed Nm1 does not exceed predetermined value N0 (NO in S73), ECU 200 performs EHC energization in S74. Let it continue.

  On the other hand, when EHC energization time T exceeds predetermined time T0 (YES at S72), or when first MG rotation speed Nm1 exceeds predetermined value N0 (YES at S73), ECU 200 performs the process at S82. The EHC energization is stopped.

  When engine 10 has been started (YES in S60), ECU 200 switches the control mode from the start mode to the engine mode in S80, and stops the power generation of first MG 21. Thereafter, the ECU 200 determines whether or not EHC is energized in S81. If EHC is not energized (NO in S81), ECU 200 ends the process. If EHC is being energized (YES in S81), ECU 200 stops EHC energization in S82.

  As described above, ECU 200 according to the present embodiment reduces acceptable power value Win of battery 70 to limit value W0 lower than reference value W1 when cranking accompanied by power generation of first MG 21 during EV traveling. When it is running, EHC energization is performed. As a result, surplus electric power that cannot be received by the battery 70 in the cranking generated electric power can be consumed by the EHC 140, so that the upper limit vehicle speed Vmax during EV traveling can be maintained at the vehicle speed V1. Thereby, compared with the case where upper limit vehicle speed Vmax is reduced, deterioration of fuel consumption can be suppressed and deterioration of engine startability can be suppressed.

  Further, by surplus power α generated during cranking being consumed by the EHC 140, the temperature Tehc of the EHC 140, which has decreased during EV traveling, can be raised in advance immediately before the engine 10 is started and brought close to the activation temperature. Therefore, it is possible to effectively utilize the surplus power α as power for heating the EHC 140 to improve the exhaust gas purification performance when starting the engine.

  FIG. 6 is a diagram illustrating an example of how the temperature Tehc of the EHC 140 changes. In FIG. 6, times t1 and t4 indicate cranking start time, times t2 and t5 indicate engine start time, and time t3 indicates engine stop time. As shown in FIG. 6, when the EHC energization is performed at the cranking start time t1 (time t4), the temperature Tehc of the EHC 140 rises in advance and approaches the activation temperature before the engine start time t2 (time t5). Therefore, it is possible to improve the exhaust gas purification performance when starting the engine as compared with the prior art.

  The vehicle to which the present invention can be applied is not limited to the vehicle 1 shown in FIG. 1, but an engine, an EHC, a rotating electrical machine capable of generating torque for cranking the engine by generating power, Any vehicle including a power storage device capable of transmitting and receiving electric power to and from the rotating electrical machine may be used. In such a vehicle, when cranking accompanied by power generation by the rotating electrical machine is performed, if the acceptable power value of the power storage device is reduced to a value lower than the reference value, the EHC and the rotating electrical machine are electrically connected. It is sufficient that the EHC is energized by connecting them.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 vehicle, 10 engine, 40 power split device, 50 speed reducer, 60 PCU, 70 battery, 80 drive wheel, 100 power supply, 130 exhaust passage, 140 EHC, 151 monitoring unit, 152 current sensor, 153 voltage sensor, 154 rotation speed Sensor, 155, 156 resolver, 157 vehicle speed sensor, 158 accelerator pedal position sensor, 159 air conditioning sensor, 200 ECU, 210 engine start request determination unit, 220 mode switching unit, 230 Win limiting unit, 240 EHC energization control unit.

Claims (6)

Electric power is transferred between the engine, an electrically heatable catalyst device that purifies the exhaust of the engine, a rotating electrical machine that can generate torque for generating engine cranking by generating electricity, and the rotating electrical machine A vehicle control device including a power storage device capable of:
A switching device for switching an electrical connection state between the power storage device and the rotating electrical machine and the catalyst device;
An energization control unit that controls energization of the catalyst device by controlling the switching device;
When the cranking accompanied by the power generation of the rotating electrical machine is performed, the energization control unit is configured to rotate the catalyst device and the rotation when the acceptable power value of the power storage device is lower than a reference value. A control device for a vehicle, wherein the catalyst device is energized by being electrically connected to an electric machine. The control device further includes an engine starter that performs cranking by generating electric power according to a vehicle speed with the rotating electrical machine when starting the engine while the vehicle is running with the engine stopped.
When the cranking is performed while the vehicle is running with the engine stopped, the energization control unit reduces the acceptable power value to a value lower than the reference value and the vehicle speed is greater than or equal to a threshold vehicle speed. The vehicle control device according to claim 1, wherein energization of the catalyst device is started at a certain time.   3. The vehicle control according to claim 2, wherein the threshold vehicle speed is set to be equal to or less than a vehicle speed at which the electric power generated by the rotating electrical machine at the time of cranking becomes the acceptable power value after being reduced below the reference value. apparatus. The engine starting unit starts the engine when at least the vehicle speed exceeds the upper limit vehicle speed,
The vehicle control device according to claim 3, wherein the upper limit vehicle speed is a fixed value higher than the threshold vehicle speed.   The energization control unit, when starting of the engine is completed after the energization of the catalyst device is started, and when the energization time of the catalyst device exceeds a predetermined time, power generation of the rotating electrical machine at the time of cranking is unnecessary. 2. The vehicle control device according to claim 1, wherein energization of the catalyst device is stopped in at least one of cases where the rotation speed of the rotating electrical machine is included in the region to be formed.   The vehicle control device according to claim 1, wherein the vehicle is a hybrid vehicle including an electric motor that generates a vehicle driving force together with the engine.

Images