JP5794030B2 - Control device for hybrid vehicle - Google Patents

Description

  The technology disclosed herein relates to a control apparatus for a hybrid vehicle including a motor and an engine that output driving force to wheels.

  In recent years, hybrid vehicles equipped with an engine and a motor as a drive source for vehicles are becoming widespread (see, for example, Patent Documents 1 and 2). In the hybrid vehicle described in these patent documents, the motor running that stops the engine and runs only by the driving force of the motor, and the engine running that runs the engine and runs by the driving force of the engine (however, The driving force may be used together) according to the required driving force.

  In such a hybrid vehicle, since the engine is intermittently operated during the traveling, for example, Patent Document 1 discloses that the active state of the catalyst is maintained in preparation for switching to the engine traveling during the motor traveling. In addition, when the catalyst temperature decreases and its activation becomes necessary, the engine is operated in a no-load state by opening a clutch disposed on the drive path between the engine and the drive wheels, A technique for activating the catalyst early by retarding the ignition timing is described.

JP 2004-92428 A JP 2010-76712 A

  By the way, for example, a plug-in hybrid vehicle travels by switching between a CD (Charge Depleting) range and a CS (Charge Sustaining) range according to the state of charge (SOC) of the battery. The CD range is driven by the motor as much as possible and limits the running by the engine. However, when the required driving force is large and exceeds the upper limit output (for example, continuous rating) of the motor, the engine is started and the engine is started. The driving force must be output to the wheels. Therefore, considering emission performance, it is necessary to maintain the engine in a predetermined warm-up state and maintain the catalyst in a predetermined active state in preparation for engine start-up and operation even in the CD range. For example, in the CD range, when the engine temperature drops below a predetermined temperature and when the catalyst temperature drops below a predetermined temperature, the engine is started to warm up the engine and activate the catalyst. Then, the engine can be maintained in a predetermined warm-up state and the catalyst can be maintained in a predetermined active state.

  However, in order to warm up the engine, it is efficient to operate the engine at a high load. On the other hand, in order to activate the catalyst, the ignition timing is used to increase the exhaust temperature at a light load on the engine. The engine operating state efficient for warming up the engine and the engine operating state efficient for activating the catalyst are different from each other.

  On the other hand, since the operating state of the started engine is set according to the required driving force at that time, the engine is started based on the engine temperature and the catalyst temperature to warm up the engine and activate the catalyst. Even so, the engine operating condition at that time is not always efficient for warming up the engine and activating the catalyst. For example, even if you want to warm up the engine, the required driving force is low and the engine can only be operated at a low load, or conversely, you want to activate the catalyst. The driving force is high and the engine must be operated at a high load. This results in a wasteful increase in fuel consumption required for warming up the engine and activating the catalyst.

  The technology disclosed herein has been made in view of the above points, and the object of the technology is to consume the fuel necessary for maintaining the engine warm-up state and the catalyst active state in the hybrid vehicle. It is to reduce.

  The inventors of the present application do not immediately start the engine to warm up the engine or activate the catalyst when it is necessary to warm up the engine or activate the catalyst. The engine is warmed up and the catalyst is activated more efficiently by waiting for the engine to start until the required driving force suitable for the engine is reached or until the required driving force suitable for catalyst activation. To reduce fuel consumption.

  Specifically, the technology disclosed herein relates to a control device for a hybrid vehicle, and a motor and an engine configured to output driving force to wheels, respectively, and a catalyst disposed on an exhaust passage of the engine And a controller configured to control the engine and the motor according to a required driving force.

  The controller outputs only the driving force of the motor to the wheels by stopping the engine and operating the motor when the required driving force is equal to or less than a predetermined switching value. Is higher than the switching value, at least the engine is operated to output at least the driving force of the engine to the wheels, and the controller also maintains the engine in a predetermined warm-up state and the catalyst So that the engine is warmed up and the catalyst is activated by operating the engine even when the required driving force is equal to or less than the switching value so as to maintain the active state of the catalyst. Is performed when the required driving force is lower than a reference value, and the engine is warmed up when the required driving force is equal to or higher than the reference value. Cormorant.

  Here, “when the catalyst needs to be activated” is when the catalyst purification rate is equal to or lower than a preset reference value, and can be determined, for example, based on the temperature of the catalyst.

  According to the above configuration, when the requested driving force is equal to or less than the predetermined switching value, the controller stops the engine and operates the motor, thereby outputting only the driving force of the motor to the wheels. This corresponds to the motor running state. On the other hand, when the required driving force is higher than the switching value, at least the engine driving force is output to the wheel by operating the engine. This may be a combined running state in which both the engine and the motor are operated and their driving power is output to the wheels, or an engine running state in which only the driving force of the engine is output to the wheels.

  In addition, the controller warms up the engine by operating the engine even when the required driving force is below the switching value so as to maintain the engine in a predetermined warm-up state and maintain the catalyst in a predetermined active state. And activation of the catalyst. For example, when the temperature of the engine falls below a predetermined temperature, the engine is started and the engine is warmed up even if the required driving force is less than or equal to the switching value. Further, when the activation state of the catalyst falls below a predetermined state, the engine is started and the catalyst is activated even if the required driving force is equal to or less than the switching value.

  And while warming up the engine is efficient to operate the engine at a high load, the activation of the catalyst is efficient to operate the engine at a low load. When the engine can be operated at a low load because the required driving force is lower than the reference value, the catalyst is activated, and when the engine can be operated at a high load because the required driving force is greater than the reference value, Warm up the engine. This makes it possible to efficiently perform both catalyst activation and engine warm-up, and reduce the amount of fuel required for maintaining the engine warm-up state and maintaining the catalyst active state. .

When the catalyst is activated, the controller operates in an activity promotion mode in which the engine is operated with a light load and the combustion timing is retarded to increase the exhaust gas temperature, thereby promoting the activity of the catalyst. you operation.

Here, in order to operate the engine in the “activation promotion mode capable of promoting the activity of the catalyst”, it is possible to adopt various known methods. When the engine is a spark ignition engine, for example, Examples of such operations include retarding the ignition timing to retard the combustion timing and increase the exhaust temperature. Further, when the engine is a compression ignition type engine, for example, an operation that retards the combustion timing and raises the exhaust gas temperature is exemplified by measures such as retarding the injection timing.

  By doing so, the activation of the catalyst is efficiently performed in a short time, and the fuel consumption required for it is further reduced.

A first state related to the active state of the catalyst and a second state corresponding to an active state lower than the first state are set, and the controller sets the active state of the catalyst to the first state. When the required driving force falls below the reference value, the catalyst is activated by operating the engine in the activation promotion mode, and the activation state of the catalyst is less than the second state. when the also the required driving force is not lower than the reference value, it intends row activation of the catalyst by operating the engine in the active demonstration mode.

  According to this configuration, when the activation state of the catalyst falls below the first state, the catalyst needs to be activated, but the engine is started after waiting for the required driving force to fall below the reference value, and the catalyst By performing the activation, it becomes possible to efficiently activate the catalyst. On the other hand, when the active state of the catalyst falls below the second state, the active state of the catalyst is significantly low. If the catalyst is shifted to the combined traveling state or the engine traveling state in this state, the emission performance is greatly deteriorated. Since there is a concern, it is desirable to activate the catalyst at an early stage. Therefore, when the active state of the catalyst falls below the second state, the engine is started and the catalyst is activated without waiting for the required driving force to fall below the reference value. This avoids deterioration of emission performance.

A first temperature related to the temperature of the engine and a second temperature lower than the first temperature are set, and the controller has an activation state of the catalyst equal to or higher than the first state, and the temperature of the engine There when the front SL and the required driving force lower than the first temperature is equal to or higher than the reference value, to perform the warming up of the engine effectively, both when you operate the engine at high load, the catalyst When the activation state of the engine is equal to or higher than the first state and the temperature of the engine falls below the second temperature, the engine can be warmed up efficiently even if the required driving force does not exceed the reference value. The engine is operated at a high load to perform, or the motor is stopped and the engine is operated .

  According to this configuration, when the engine temperature falls below the first temperature, the engine needs to be warmed up. However, the engine is started after the required driving force exceeds the reference value, and the engine is warmed up. By performing the operation, it becomes possible to efficiently warm up the engine. On the other hand, when the temperature state of the engine falls below the second temperature, the engine temperature is significantly low. If the engine temperature state is shifted to the combined driving state or the engine driving state in this state, the emission performance may be deteriorated. Therefore, it is desirable to warm up the engine early. Therefore, when the temperature state of the engine falls below the second temperature, the engine is started and the engine is warmed up without waiting for the required driving force to exceed the reference value. This avoids deterioration of emission performance.

  As described above, according to the control apparatus for a hybrid vehicle, when the required driving force is equal to or less than the switching value so as to maintain the engine in a predetermined warm-up state and maintain the catalyst in a predetermined active state. By operating the engine, the engine is warmed up and the catalyst is activated, while the activation of the catalyst is performed when the engine can be operated at a low load because the required driving force is lower than the reference value, Engine warm-up is performed when the engine can be operated at a high load because the required driving force is above the reference value, so that the consumption of fuel necessary for maintaining the engine warm-up state and maintaining the catalyst active state is performed. The amount can be reduced.

1 is an overall block diagram of a vehicle powertrain and a control device. It is a figure which shows an example of the change of an engine speed, and the change of SOC of a battery about each of CD range and CS mode. It is a figure which shows an example of sharing of the driving force of the motor with respect to a required driving force and the driving force of an engine in CD range. It is an example of the characteristic map of an engine. It is a flowchart which concerns on the engine and motor control in progress which a controller performs. It is a figure which shows an example of the change of (a) catalyst temperature regarding catalyst activation, (b) engine water temperature, (c) engine torque, (d) motor torque, and (e) required drive force. FIG. 7 is a diagram showing an example different from FIG. 6 of (a) catalyst temperature, (b) engine water temperature, (c) engine torque, (d) motor torque, and (e) required drive force change related to catalyst activation. . It is a figure which shows an example of the change of (a) catalyst temperature regarding engine warm-up, (b) engine water temperature, (c) engine torque, (d) motor torque, and (e) required drive force. It is a figure which shows the example different from FIG. 8 of the change of (a) catalyst temperature regarding engine warm-up, (b) engine water temperature, (c) engine torque, (d) motor torque, and (e) required drive force. .

  Hereinafter, an embodiment of a control device for a hybrid vehicle will be described with reference to the drawings. In addition, the following description of preferable embodiment is an illustration. FIG. 1 is an overall block diagram of a vehicle powertrain and control device. The power train PT includes an engine 11 that generates a driving force, a gear transmission mechanism 12 that is connected to the engine 11 and performs a shift, and a differential device that receives the output from the gear transmission mechanism 12 and distributes the driving force to the left and right. 13, left and right drive wheels (for example, front wheels) 14 and 14 that receive the driving force from the differential device 13, a torque converter (fluid electric device) 15 disposed between the engine 11 and the gear transmission mechanism 12, An electric motor 16 disposed downstream of the gear transmission mechanism 12 in the driving force transmission direction and driving the driving wheel 14 through the differential device 13. This hybrid vehicle is a so-called parallel hybrid vehicle including an engine 11 and an electric motor 16 as drive sources. As will be described later, the hybrid vehicle is electrically driven according to a required driving force set based on the vehicle speed and the accelerator opening. The motor 16 is configured to travel while switching between at least two traveling states: a motor traveling state in which the motor 16 is operated and the engine 11 is stopped, and a combined traveling state in which both the electric motor 16 and the engine 11 are operated.

  Although detailed illustration is omitted, the engine 11 is, for example, a four-cycle spark ignition engine. The engine 11 includes a generator connected to a crankshaft via a belt, and this generator is a BISG 21 in which a starter and a generator are integrated. On the exhaust passage 22 connected to the exhaust side of the engine 11, for example, a three-way catalyst 23 (hereinafter simply referred to as the catalyst 23) for purifying exhaust gas is disposed.

  Although detailed illustration is omitted, the gear transmission mechanism 12 includes, for example, a plurality of clutch elements as a planetary gear mechanism and a frictional engagement element that selectively restricts the rotation of each rotation element included in the planetary gear mechanism. And a multi-stage automatic transmission configured to include a brake element. The gear transmission mechanism 12 is configured to realize each gear stage by engaging at least two elements selected from a plurality of clutch elements and brake elements. In other words, the gear transmission mechanism 12 is configured so that the torque between the engine 11 and the drive wheels 14 is reduced by fastening at least two elements to achieve a drive state in which a predetermined shift speed is achieved and not fastening all of the elements. Since the transmission is switched to the neutral state in which the transmission is cut off, particularly in this hybrid vehicle, as described later, the gear transmission mechanism 12 is operated by switching the release and engagement of the clutch elements and brake elements. 11 and the driving wheel 14 are made to function as the intermittent means 121 for intermittently torque. This intermittent means 121 is effective in avoiding a drag phenomenon in which the engine 11 is driven to rotate while being dragged in conjunction with the traveling of the vehicle.

  The electric motor 16 is, for example, a three-phase AC synchronous motor, and is driven by a drive current supplied via a battery and an inverter (not shown). Here, in the motor running mode, the vehicle is running with the driving force of the electric motor 16, the vehicle is running while regenerating the electric motor 16, and the electric motor 16 runs without inertia at all. Including at least three states.

  The vehicle control device CR operates the engine 11 (including start control of the engine 11 through the BISG 21), operates the electric motor 16 through control of the inverter (including power running and regeneration), and the gear stage of the gear transmission mechanism 12. It is a device that controls each of the above. The control device CR is configured to include a controller 3 and various sensors 31 to 36 that detect various states including the traveling state of the vehicle and provide the controller 3. Among these, the controller 3 is a normal microcomputer, for example, and although not shown, is configured to include at least a CPU, a ROM, a RAM, an I / O interface circuit, and a data bus.

  The various sensors include at least a vehicle speed sensor 31 that provides information related to the traveling speed of the vehicle to the controller 3, an accelerator opening sensor 32 that provides information related to the accelerator opening corresponding to the amount of depression of the accelerator pedal to the controller 3, a battery. Information relating to various states of the battery, including information relating to the state of charge (SOC) of the battery and the battery temperature, information relating to the state of the electric motor 16 such as the electric motor 16 Motor state sensor 34 that provides the temperature information of the catalyst 23, information relating to the purification rate of the catalyst 23, for example, a catalyst state sensor 35 that provides temperature information of the catalyst 23, and a water temperature sensor 36 that provides information on the cooling water temperature of the engine 11. Is included. The controller 3 takes in sensor signals from these sensors 31 to 36 and performs arithmetic processing to control the engine 11, the BISG 21, the gear transmission mechanism 12, and the electric motor 16.

  Here, the catalyst state sensor 35 is provided, but instead of this, for example, the catalyst temperature or the purification rate is estimated from the engine water temperature or the history information of the operating state of the vehicle (engine). May be.

  Specifically, the controller 3 activates and stops the electric motor 16 and switches the engine 11 to switch between the above-described motor traveling state and the combined traveling state according to the required driving force set based on the vehicle speed and the accelerator opening. Switch between operation and stop (start and stop). At the same time, the controller 3 controls the gear transmission mechanism 12 such as shift control according to the shift map, and intermittent switching of torque between the engine 11 and the drive wheels 14 by the intermittent means 121 according to switching of the running state. I do.

  Here, although the illustration of the configuration of this hybrid vehicle is omitted, the hybrid vehicle is a plug-in hybrid vehicle capable of charging a battery by external power feeding, and may be referred to as “battery running” or “plug-in running”. The CD range that can be switched and the CS range that can be referred to as “charging maintenance traveling” or “hybrid traveling” are switched according to the SOC of the battery (see FIG. 2). In other words, when the SOC of the battery is equal to or greater than the first predetermined value, it is in the CD range as shown on the left side of FIG. 2. In this CD range, motor driving is basically performed and engine operation is suppressed. For example, when the hybrid vehicle is started after the charging of the battery is completed by power supply from the outside, the CD range is set while the SOC is reduced to the first predetermined value. In the CD range, the power consumption of the battery is allowed, but the charging of the battery by the operation of the engine 11 is restricted, so that the SOC gradually decreases. Then, when the SOC falls below the first predetermined value, the driving range of the hybrid vehicle is switched to the CS range. In the CS range, the engine 11 is frequently started and stopped in accordance with the SOC so that the SOC is maintained within a range between the first predetermined value and a second predetermined value that is higher than the first predetermined value by a predetermined value. It is driven and the battery is charged.

  As described above, in the CD range, power consumption of the battery is prioritized and the operation of the engine 11 is suppressed. However, for example, if the required driving force increases to a predetermined value or more, the electric motor 16 alone cannot satisfy the required driving force. Therefore, as shown in FIG. 2, the engine 11 is started and the driving force of the engine is used as an auxiliary. FIG. 3 shows an example of sharing the driving force of the electric motor 16 and the driving force of the engine 11 with respect to the required driving force in the CD range. In the CD range, the upper limit driving force of the electric motor 16 is set in advance. When the required driving force is equal to or lower than the upper limit driving force, the electric motor 16 is operated and the engine 11 is stopped. The required driving force is satisfied only with the driving force. Here, the upper limit driving force of the electric motor 16 may be set based on the continuous rating of the electric motor 16. For example, the upper limit driving force of the electric motor 16 may be matched with the continuous rating of the electric motor 16. The upper limit driving force of the electric motor 16 corresponds to a switching value for switching between the motor traveling state and the combined traveling state with respect to the required driving force in the CD range.

  On the other hand, when the required driving force exceeds the upper limit driving force of the electric motor 16, the engine 11 is operated, and the required driving force is satisfied by the driving forces of both the electric motor 16 and the engine 11. Here, as shown in FIG. 4, in this hybrid vehicle, the engine 11 is operated so as to increase the efficiency based on the engine characteristics. That is, the engine 11 is operated along a high-efficiency line indicated by “normal operation line” in FIG. 4, and in particular, a high-efficiency region indicated by a broken line in FIG. For this reason, since the engine 11 is operated so as to output a predetermined torque or more, when the required driving force is satisfied by the driving force of both the electric motor 16 and the engine 11 described above, the output of the engine 11 is output. Is set to a predetermined value or more, while the required driving force is satisfied by reducing the output of the electric motor 16. Note that, in the low rotation range, the efficiency of the engine 11 is reduced, so the engine 11 is stopped. The engine 11 is basically operated along the “normal operation line” in both the CD range and the CS range. However, in the CD range, as described above, power consumption is allowed and fuel consumption is performed. From the standpoint of suppressing, an operation line different from the operation line in the solid CS range is set in the low rotation range as shown by the broken line.

  As described above, in the CD range, the operation of the engine 11 is suppressed, and the engine 11 is hardly operated. On the other hand, when the required driving force exceeds the switching value, the engine 11 needs to be operated. At this time, if the engine 11 is not warmed up or the catalyst 23 is not activated, the emission performance is deteriorated. Therefore, also in the CD range, the engine 11 must be maintained in a predetermined warm-up state and the catalyst 23 must be maintained in a predetermined active state. However, warm-up of the engine 11 and activation of the catalyst 23 must be performed by intermittently operating the engine 11 regardless of the magnitude of the required driving force, while warm-up of the engine 11 It is efficient to operate at a high load, and activation of the catalyst 23 is efficient to operate the engine 11 at a low load. Therefore, if the engine 11 is operated only based on the temperature of the engine 11 or the active state of the catalyst 23 and the engine 11 is warmed up or the catalyst 23 is activated, the engine 11 is warmed up or the catalyst 23 is activated. Therefore, the fuel consumption cannot be increased efficiently, and the amount of fuel consumption increases.

  Therefore, in this hybrid vehicle, the engine 11 is not started immediately when the engine 11 needs to be warmed up or the catalyst 23 needs to be activated, but by starting the engine 11 according to the required driving force. The warm-up state of the engine 11 and the active state of the catalyst 23 are maintained in the CD range without unnecessarily increasing the fuel consumption.

  FIG. 5 is a flowchart relating to control of the engine 11 and the electric motor 16 in the CD range, which is executed by the control device CR. First, this flow is started in the motor running state in the CD range, and in step S51 after the start, the controller 3 provides information on each sensor 31 to 36, information on at least accelerator opening, vehicle speed, catalyst temperature, and motor temperature. Is read. In a succeeding step S52, it is determined whether or not the engine water temperature Tw is higher than the first temperature TW1. The first temperature TW1 is a temperature set in advance as a temperature that requires the engine 11 to be warmed up because the engine water temperature is low. The first temperature TW1 may be appropriately set, for example, at about 50 to 60 ° C., and the first temperature TW1 may be set to 60 ° C. at which air-fuel ratio feedback control is possible. When the engine water temperature is higher than the first temperature TW1 (YES), the process proceeds to step S53, and when the engine water temperature is equal to or lower than the first temperature TW1 (NO), the process proceeds to step S510.

  In step S53, it is determined whether the catalyst temperature Tc is lower than the first temperature TC1. The first temperature TC1 is a temperature set in advance as a temperature that requires activation of the catalyst 23 because the temperature of the catalyst 23 is low, and the first temperature TC1 may be appropriately set at about 280 ° C., for example. When the determination in step S53 is NO, in other words, because the engine 11 is in the warm-up state and the catalyst 23 is in the active state, the process proceeds to step S59, and the motor travel is continued without starting the engine 11. . On the other hand, when the determination in step S53 is YES, in other words, when the catalyst 23 needs to be activated, the process proceeds to step S54.

  In step S54, it is determined whether or not the catalyst temperature Tc is higher than the second temperature TC2. The second temperature TC2 may be appropriately set as a temperature corresponding to the reaction limit of the catalyst 23, and the second temperature TC2 may be appropriately set at about 250 ° C., for example. Accordingly, the first temperature TC1> the second temperature TC2. When the determination in step S54 is YES, the process proceeds to step S55. That is, although the temperature of the catalyst 23 is lower than the first temperature TC1 and the catalyst 23 needs to be activated, it is higher than the second temperature TC2 and does not need to be activated immediately, so the required driving force is low. The catalyst 23 is activated after waiting. On the other hand, when the determination in step S54 is NO, since the temperature of the catalyst 23 is equal to or lower than the second temperature TC2, the process proceeds to step S56 in order to immediately start the activation of the catalyst 23.

  In step S55, it is determined whether the required driving force set based on the accelerator opening and the vehicle speed is lower than the reference value F1. When the load is lower than the reference value F1 (that is, when YES), the process proceeds to step S56. On the other hand, when the required driving force is greater than or equal to the reference value F1 (that is, when NO), the process proceeds to step S59, and the start of activation of the catalyst 23 is delayed.

  In step S56, the engine 11 is started to operate at a light load, and the ignition timing is greatly retarded. Such an operation mode increases the exhaust gas temperature and promotes the activation of the catalyst 23 (that is, the activation promotion mode). As a result, the time required for the activation of the catalyst 23 is shortened, which is advantageous in suppressing fuel consumption. When the engine 11 is operated in the activation promotion mode to activate the catalyst 23, the output of the electric motor 16 is adjusted according to the required driving force and the engine load. When the required driving force is satisfied by the engine load, the electric motor 16 is stopped.

  In step S57, it is determined whether or not the activation of the catalyst 23 is completed. When the activation is not completed (NO), the activation of the catalyst 23 is continued while the activation is completed. If yes (YES), the process proceeds to step S58. Whether or not the activation of the catalyst 23 has been completed may be determined based on, for example, the temperature of the catalyst 23. When the temperature of the catalyst 23 becomes higher than the first temperature TC1, the activation of the catalyst 23 is determined. You may determine with having completed. Then, in step S58 where the activation of the catalyst 23 is completed, the engine 11 is stopped and returned to the motor running state.

  On the other hand, in step S510, where the engine water temperature Tw is shifted to be equal to or lower than the first temperature TW1, it is determined whether the catalyst temperature Tc is higher than the first temperature TC1, as in step S53. When the determination in step S510 is YES, in other words, when the catalyst 23 is activated, the process proceeds to step S511. On the other hand, when the determination in step S510 is NO, in other words, when activation of the catalyst 23 is necessary, the process proceeds to step S54. Thus, the activation of the catalyst 23 is prioritized over the warm-up of the engine 11. This is advantageous for improving the emission performance.

  In step S511, it is determined whether or not the engine water temperature Tw is higher than the second temperature TW2. If Tw> TW2 (YES), the process proceeds to step S512. The second temperature TW2 is, for example, a lower limit temperature related to the emission of the engine 11, that is, a temperature set in advance as the temperature of the engine 11 at which the emission performance deteriorates, and is lower than the first temperature TW1, for example, about 45 ° C. And set as appropriate. On the other hand, when Tw ≦ TW2 (NO), the process proceeds to step S513 to immediately warm up the engine 11.

  In step S513, the engine 1 is started and the engine 11 is warmed up. At this time, the load of the engine 11 is determined in accordance with the required driving force, but it is preferable to stop the electric motor 16 in order to make the engine load as high as possible and to advantageously warm up the engine 11.

  In step S512, it is determined whether or not the required driving force is greater than or equal to the reference value F1, and when this determination is NO, the process proceeds to step S517 to continue motor running. That is, the water temperature of the engine 11 is lower than the first temperature TW1 and the engine 11 needs to be warmed up. It waits for high demand driving force that is advantageous to On the other hand, when the determination in step S512 is YES, the process proceeds to step S514, the engine 11 is started, and the engine 11 is operated at a high load so as to correspond to the high required driving force. Promote.

  In step S515, it is determined whether or not the warm-up of the engine 11 has been completed. When the warm-up has not been completed (NO), the engine 11 continues to be warmed up. When completed (YES), the process proceeds to step S516, the engine 11 is stopped, and the motor travel state is restored.

  Next, the above-described control of the engine 11 and the electric motor 16 in the CD range will be described with reference to FIGS. First, FIG. 6 shows an example in which the engine 11 is started and the activation of the catalyst 23 is started when the catalyst temperature Tc is lower than the first temperature TC1 and the required driving force is lower than the reference value F1. is there. That is, as shown in FIG. 6 (a), it is assumed that the temperature Tc of the catalyst 23 gradually decreases and falls below the first temperature TC1 at the timing T1. As described above, the engine 11 is immediately started at this timing T1 and the catalyst 23 is not activated, but waits until the required driving force becomes a low load state advantageous for the activation of the catalyst 23 (FIG. 6 (c)).

  Then, as shown in FIG. 6E, if the required driving force falls below the reference value F1 at the timing T2, the engine 11 is started and the engine 11 is made to correspond to the required driving force. Operate in an activity promotion mode with a light load and significantly retarded ignition timing. In the illustrated example, since the required driving force is satisfied by the driving force of the engine 11, the electric motor 16 is stopped during the activation promotion mode (see FIG. 6D). Thus, as shown in FIG. 6A, the temperature of the catalyst 23 gradually increases. Since the engine 11 is operated with a light load, the temperature of the engine 11 hardly rises.

  Then, as shown in FIG. 6A, if the temperature Tc of the catalyst 23 exceeds TC1 at timing T3, the activation of the catalyst 23 is completed, and the engine 11 is stopped and the electric motor 16 is operated to request Satisfy the driving force. That is, the motor travels back (see FIGS. 6C, 6D, and 6E).

  FIG. 7 shows an example in which the catalyst temperature Tc falls below the second temperature TC2 after the catalyst temperature Tc falls below the first temperature TC1 at the timing T1 and before the required driving force falls below the reference value F1. This is shown (see FIGS. 7A and 7E). That is, for example, when the temperature of the catalyst 23 rapidly decreases due to the low outside air temperature and becomes lower than the second temperature TC2 at the timing T2, the engine 11 is started even if the required driving force is equal to or higher than the reference value F1. Then, activation of the catalyst 23 is started.

  The engine 11 that has started is operated in an activation promotion mode in which the load is light and the ignition timing is significantly retarded, as described above. Thus, activation of the catalyst 23 is promoted (FIGS. 7A and 7C), and the output of the electric motor 16 is adjusted according to the load of the engine 11 so as to satisfy the required driving force. 7D, the torque of the electric motor 16 is reduced at the timing T2 when the engine 11 is started, and the required driving force is reduced at the timing T3, and the required driving force is satisfied by the torque of the engine 11. Therefore, the electric motor 16 is stopped, that is, the engine is running, and at the timing T4 when the temperature of the catalyst 23 exceeds the first temperature TC1, the engine 11 is stopped and the motor is running. The state is switched (see FIGS. 7A, 7C, 7D, and 7E).

  FIG. 8 shows an example in which the engine 11 is started and the engine 11 is warmed up when the engine water temperature Tw is lower than the first temperature TW1 and the required driving force is increased to the reference value F1 or more. That is, as shown in FIG. 8B, at the timing T1 when the water temperature Tw of the engine 11 gradually decreases and falls below the first temperature TW1, the required driving force is not started without starting the engine 11. 11 waits for a high driving force advantageous for warm-up. Then, as shown in FIG. 8 (e), the engine 11 is started at the timing T2 when the required driving force becomes equal to or greater than the reference value F1. At this time, in the illustrated example, the electric motor 16 is stopped in order to increase the warm-up efficiency of the engine 11 by operating the engine 11 with as high a load as possible (see FIG. 8D). As a result, as shown in FIG. 8 (b), the water temperature of the engine 11 is rapidly increased, and the engine 11 is stopped at the timing T3 when the temperature becomes equal to or higher than the first temperature TW1, assuming that the engine 11 has been warmed up. To do. On the other hand, the electric motor 16 is operated so as to satisfy the required driving force. That is, it returns to the motor running state.

  FIG. 9 shows an example in which the water temperature Tw is lower than the second temperature TW2 after the water temperature Tw of the engine 11 is lower than the first temperature TW1 at the timing T1 and before the required driving force becomes equal to or higher than the reference value F1. This is shown (see FIGS. 9B and 9E). That is, when the water temperature of the engine 11 becomes lower than the second temperature TW2, even if the required driving force is lower than the reference value F1, the engine 11 is started and warming up of the engine 11 is started (FIG. 9 (c) )reference). At this time, in the figure, while the required drive amount is low, the electric motor 16 is stopped from the viewpoint of increasing the load of the engine 11 as much as possible (FIGS. 9C, 9D, and 9E). Further, if the required driving force is increased at timing T3, the load of the engine 11 is increased while the electric motor 16 is stopped so that the required driving force is satisfied. Thus, warming up of the engine 11 is promoted as much as possible.

  The engine 11 is stopped and the electric motor 16 is operated at a timing T4 when the water temperature Tw of the engine 11 exceeds the first temperature TW1, thereby returning to the motor running state.

  As described above, in this hybrid vehicle, in order to maintain the warm-up state of the engine 11 and maintain the activated state of the catalyst 23 in the CD mode, according to the water temperature of the engine 11 and the temperature of the catalyst 23, Although the engine 11 is started, when the catalyst 23 is activated, the engine 11 is started after waiting for the required driving force to fall below the reference value F1, while the engine 11 is warmed up. Is performed after the required driving force reaches the reference value F1 or more. As a result, the activation of the catalyst 23 and the warm-up of the engine 11 can be performed efficiently, respectively, and the consumption of fuel necessary for the activation of the catalyst 23 and the warm-up of the engine 11 can be reduced, while the catalyst It is possible to maintain the active state of 23 and the warm-up state of the engine 11.

  On the other hand, when the water temperature Tw of the engine 11 becomes equal to or lower than the second temperature TW2 or the temperature Tc of the catalyst 23 becomes equal to or lower than the second temperature TC2, the engine 11 is immediately started to warm up the engine 11 or the catalyst 23. In the CD range, even when the motor running state is switched to the engine running state or the combined running state in the CD range, it is avoided that the emission performance is deteriorated.

  In addition, the structure of a hybrid vehicle is not restricted to the structure mentioned above, A various structure can be employ | adopted. For example, in the configuration of FIG. 1, the electric motor 16 is disposed downstream of the gear transmission mechanism 12 in the driving force transmission direction. However, the electric motor 16 is disposed upstream of the gear transmission mechanism 12 in the driving force transmission direction. And the output of the electric motor may be output to the drive wheel 14 via the gear transmission mechanism 12.

  The electric motor 16 does not distribute the driving force from one electric motor to the left and right driving wheels 14 via the differential device 13 as described above, but independently to the left and right driving wheels 14. You may provide an at least 2 electric motor so that a driving force may be provided. In that case, an in-wheel motor may be employed.

  Furthermore, the driving force of the electric motor 16 is not limited to being applied to the front wheels, and may be applied to the rear wheels. Similarly, the driving force of the engine 11 is not limited to being applied to the front wheels, and may be applied to the rear wheels. Here, the wheel for applying the driving force of the electric motor 16 and the wheel for applying the driving force of the engine 11 may be the same as shown in FIG. 1 or may be different (for example, the engine 11). Before, after the drive force of the electric motor 16, or vice versa. For example, when the driving force of the electric motor 16 is applied to the rear wheels, the electric motor 16 may be connected to the middle of the drive shaft without being limited to the configuration in which the electric motor 16 is connected to the driving shaft of the rear wheel.

  In the power train PT, a continuously variable transmission mechanism such as a belt type may be employed instead of the gear-type multi-speed transmission mechanism.

  Furthermore, the engine 11 may employ a compression ignition type engine (diesel engine) instead of the spark ignition type. In this case, in order to operate the compression ignition type engine in the active activation mode, the combustion period may be delayed to raise the exhaust gas temperature, for example, by changing (retarding) the injection timing.

  In addition, the control of the engine 11 and the electric motor 16 disclosed herein is not limited to the CD range, but it is more effective to perform the control within a range in which the operation of the engine 11 is limited. .

11 Engine 14 Drive wheel (wheel)
16 Electric motor 22 Exhaust passage 23 Three-way catalyst 3 Controller

Claims (1)

A motor and an engine each configured to output driving force to the wheels;
A catalyst disposed on an exhaust passage of the engine;
A controller configured to control the engine and the motor in response to a required driving force,
The controller outputs only the driving force of the motor to the wheels by stopping the engine and operating the motor when the required driving force is equal to or less than a predetermined switching value. When higher than the switching value, by driving at least the engine, at least the driving force of the engine is output to the wheels,
The controller also operates the engine when the required driving force is less than or equal to the switching value so as to maintain the engine in a predetermined warm-up state and maintain the catalyst in a predetermined active state. , Warming up the engine and activating the catalyst,
A first state related to the active state of the catalyst and a second state corresponding to an active state lower than the first state are set,
Regardless of the engine warm-up state, the controller
The engine is operated at a light load so as to efficiently activate the catalyst when the activation state of the catalyst falls below the first state and the required driving force falls below a reference value; and While operating in the activation promotion mode that retards the combustion timing and raises the exhaust temperature,
When the activation state of the catalyst falls below the second state, the engine is operated in the activation promotion mode even if the required driving force does not fall below the reference value.
A first temperature related to the temperature of the engine and a second temperature lower than the first temperature are set,
The controller is
When the activation state of the catalyst is equal to or higher than the first state, the engine temperature is lower than the first temperature, and the required driving force is equal to or higher than the reference value, the engine is efficiently warmed up. Operating the engine at high load to do so,
When the activation state of the catalyst is equal to or higher than the first state and the temperature of the engine is lower than the second temperature, the engine is efficiently warmed up even if the required driving force does not exceed the reference value. The hybrid vehicle control apparatus operates the engine at a high load, or stops the motor and operates the engine to perform the operation .

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