JP2021175619A - Hybrid vehicle - Google Patents

Abstract

To provide a hybrid vehicle that is able to reduce a catalyst warm-up period and improve fuel consumption.SOLUTION: When a catalyst is warmed up by driving a diesel engine, a required amount of generated power necessary to raise a catalyst temperature to an active temperature is firstly obtained. If a charging rate when a battery is charged with the required amount of generated power exceeds a normal upper-limit charging rate of the battery, a diesel engine is stopped, and running of a motor that is rotationally driven by power supplied from the battery is executed for a predetermined time to reduce the charging rate of the battery. Thereafter, it is determined whether the charging rate when the battery is recharged with the required amount of generated power exceeds the normal upper-limit charging rate of the battery or not. On the other hand, when it is determined that the normal upper-limit charging rate of the battery is not exceeded, the diesel engine is driven to warm up the catalyst to the active temperature, and the battery is charged with power generated by the motor generator.SELECTED DRAWING: Figure 1

Description

The present invention relates to a hybrid vehicle.

Various techniques for hybrid vehicles equipped with an engine and a motor generator have been proposed. For example, the hybrid vehicle control device described in Patent Document 1 below includes an engine in which an exhaust purification device is installed in an exhaust passage, a generator that generates power from the output of the engine, and a storage storage that stores the power generated by the generator. It is a control device for a hybrid vehicle that includes means and an electric motor driven by the electric power thereof, and travels by the output of the engine and the electric motor or the electric motor.

Then, the control device of the hybrid vehicle requests the temperature rise of the exhaust gas purification device, detects the storage state of the power storage means, and when the temperature rise request is made, the target engine output required to raise the temperature of the exhaust purification device to a predetermined temperature. Is set, the time required to raise the temperature of the exhaust gas purification device is calculated, the amount of power generation that can be generated by the target engine output is calculated, and the overcharged state is not reached based on the current power storage state and power generation amount of the power storage means. As such, it is configured to modify the target engine output.

Japanese Unexamined Patent Publication No. 2007-55348

However, in the hybrid vehicle control device described in Patent Document 1, when the battery charge rate (SOC: State of Charge) at the start of catalyst warm-up is high and the driver required torque is low. There is a risk that the catalyst warm-up period will be long and the fuel efficiency will deteriorate. Further, in this case, the amount of exhaust heat required for warming up the catalyst may be insufficient, the temperature of the catalyst may be lower than the desired catalyst temperature, and the desired catalyst purification performance may not be obtained.

Therefore, the present invention has been devised in view of such a point, and an object of the present invention is to provide a hybrid vehicle capable of shortening the catalyst warm-up period and improving fuel efficiency.

In order to solve the above problems, the first invention of the present invention is a transmission in which a diesel engine and a motor generator connected via an engine clutch and an input shaft connected to the motor generator via a motor clutch are connected. A battery electrically connected to the motor generator, a charge rate acquisition device for acquiring the charge rate of the battery, a catalyst provided in the exhaust system of the diesel engine to purify the exhaust gas, and the catalyst. A catalyst temperature detecting device for detecting the catalyst temperature, the engine clutch, the diesel engine, the motor generator, the motor clutch, the transmission, the charging rate acquisition device, and a control device connected to the catalyst temperature detecting device. When the diesel engine is driven to warm up the catalyst, the control device raises the catalyst temperature to an active temperature based on the catalyst temperature detected by the catalyst temperature detection device. The required power generation amount acquisition unit that acquires the required power generation amount required for heating, and the determination whether or not the charge rate when the required power generation amount is charged to the battery exceeds the normal upper limit charge rate of the battery. When it is determined that the charge rate when the required power generation amount is charged to the battery through the overcharge determination unit and the overcharge determination unit does not exceed the normal upper limit charge rate of the battery, the above With the engine clutch and the motor clutch in contact with each other, the diesel engine is driven to warm up the catalyst to the active temperature, and the power supply to the motor generator is stopped to generate electric power generated by the motor generator. The charge rate when the required power generation amount is charged to the battery via the catalyst warm-up control unit that controls the battery to be charged and the overcharge determination unit determines the normal upper limit charge rate of the battery. When it is determined that the engine clutch is exceeded, the engine clutch is disengaged and the motor clutch is in contact with the engine, and the diesel engine is stopped while the motor generator is rotationally driven by power supply from the battery. The control device includes a motor running control unit that controls the running of the motor for a predetermined time, and the control device executes the motor running for the predetermined time and then performs the request again via the overcharge determination unit. Control is performed so as to determine whether or not the charge rate when the battery is charged with the amount of power generated exceeds the normal upper limit charge rate of the battery. It is a hybrid vehicle.

Next, the second invention of the present invention includes the accelerator opening degree detecting device for detecting the accelerator opening degree and the vehicle speed detecting device for detecting the vehicle speed in the hybrid vehicle according to the first invention. The device is in a hybrid traveling region in which the engine clutch and the motor clutch are brought into contact with each other based on the accelerator opening degree and the vehicle speed, and the diesel engine and the motor generator are used as drive sources, and the motor traveling. The motor traveling control unit has a traveling mode setting unit for setting a traveling motor traveling region and a traveling motor traveling region, and the motor traveling control unit has a charge rate when the required power generation amount is charged to the battery via the overcharge determination unit. When it is determined that the normal upper limit charging rate of the battery is exceeded, the motor traveling area is expanded via the traveling mode setting unit for the predetermined time to control the motor traveling. , A hybrid vehicle.

Next, the third invention of the present invention is the hybrid vehicle according to the first invention or the second invention, in which the control device raises the temperature of the catalyst to the active temperature at the time of warming up the catalyst. It has a target engine torque setting unit for setting a target engine torque required for the above, and the target engine torque includes a driver required torque and a charging torque generated by the motor generator to charge the battery, and the catalyst warm-up The control unit is a hybrid vehicle that controls the diesel engine to be driven by the target engine torque.

Next, in the fourth invention of the present invention, in the hybrid vehicle according to the first invention of the first to third inventions, has the catalyst temperature reached the active temperature in the control device? It is a hybrid vehicle having a catalyst temperature determining unit for determining whether or not, and controlling to end the catalyst warm-up of the catalyst when it is determined that the catalyst temperature has reached the active temperature. ..

Next, the fifth invention of the present invention is the hybrid vehicle according to the first invention of the first to fourth inventions, wherein the catalyst selectively purifies NOx in the exhaust gas. It is a hybrid vehicle that includes a reduction catalyst.

According to the first invention, when driving a diesel engine to warm up the catalyst, first, the required power generation amount required to raise the catalyst temperature to the active temperature is obtained. Then, it is determined whether or not the charging rate when the required power generation amount is charged to the battery exceeds the normal upper limit charging rate of the battery. When it is determined that the upper limit charge rate of the battery is not exceeded, the diesel engine is driven to warm up the catalyst to the active temperature, and the generated power generated by the motor generator is charged to the battery.

On the other hand, if the charge rate when the required power generation amount is charged to the battery exceeds the normal upper limit charge rate of the battery, the diesel engine is stopped and the motor generator is rotationally driven by the power supply from the battery for a predetermined time. Run to reduce battery charge. Then, again, it is determined whether or not the charging rate when the required power generation amount is charged to the battery exceeds the normal upper limit charging rate of the battery.

As a result, when the catalyst is warmed up, the catalyst can be quickly raised to the active temperature while reliably avoiding overcharging of the battery even if the battery is charged with the generated power of the motor generator. The warm-up period can be shortened and fuel efficiency can be improved. Further, when the catalyst is warmed up by the catalyst, the charge rate of the battery can be charged to the normal upper limit charge rate or less by the generated power of the motor generator, and the motor generator can be rotationally driven by using the power of this battery. , It is possible to further improve the fuel efficiency.

According to the second invention, when the charging rate when the required power generation amount is charged to the battery exceeds the normal upper limit charging rate of the battery, the motor traveling area is expanded for a predetermined time. As a result, the control device can reliably reduce the charge rate of the battery by rotationally driving the motor generator by supplying power from the battery based on the accelerator opening degree and the vehicle speed.

According to the third invention, since the control device controls the diesel engine to be driven by the target engine torque during the catalyst warm-up, it is possible to respond to the required torque of the driver while performing the catalyst warm-up. , The motor generator can be driven by the charging torque to generate electricity and charge the battery.

According to the fourth invention, the control device terminates the catalyst warm-up when the catalyst temperature reaches the active temperature. Therefore, when the diesel engine is driven after the catalyst warm-up is completed, the exhaust gas is purified by the catalyst. Can be done.

According to the fifth invention, since the catalyst contains a selective reduction catalyst that selectively purifies NOx in the exhaust gas, the selective reduction catalyst can be warmed up to the active temperature. Therefore, when the diesel engine is driven after the catalyst warm-up is completed, NOx in the exhaust gas can be selectively purified by the selective reduction catalyst.

It is a figure explaining the schematic structure of the hybrid vehicle which concerns on this embodiment. It is a figure which shows an example of the running mode selection map which a control device selects a motor running (EV running) and a hybrid running (HEV running). It is a figure which shows an example of the engine start stop line map used when the control device switches a traveling mode. It is a figure which shows an example of the catalyst warm-up control process which catalyst-warms the catalyst executed by a control device to an active temperature. It is a time chart which showed an example of the change such as the charge rate of a battery when the catalyst is warmed up to the active temperature. It is a figure which shows an example of the exhaust temperature map used when acquiring the engine exhaust temperature at the time of driving a diesel engine. It is a figure which shows an example of the heat dissipation amount map used when acquiring the heat dissipation amount of an exhaust system with respect to a vehicle speed. It is explanatory drawing explaining the switching between the motor running (EV running) and the hybrid running (HEV running) in consideration of the amount of heat dissipation. It is a time chart which showed an example of the temperature change of a catalyst at the time of motor running (EV running) at a low load during catalyst warm-up.

Hereinafter, a detailed description will be given with reference to the drawings based on an embodiment embodying the hybrid vehicle according to the present invention. First, a schematic configuration of the hybrid vehicle 1 according to the present embodiment will be described with reference to FIG.

As shown in FIG. 1, the hybrid vehicle 1 according to the present embodiment includes a diesel engine 11, a motor generator (MG) 21, a transmission 31, and a hybrid system 20 that controls the vehicle in a complex manner according to an operating state. , A control device (ECU) 50, and the like.

The diesel engine 11 has a plurality of (four in this embodiment) cylinders 13A to 13D formed in the engine body 12, and fuel injection valves 14A to 14D are provided in the respective cylinders 13A to 13D. ing. Fuel is supplied to the fuel injection valves 14A to 14D via a common rail (not shown) and a fuel pipe (not shown), and the fuel injection valves 14A to 14D are driven by a control signal from the control device 50, respectively. Fuel is injected into the cylinders 13A to 13D.

One end of the crankshaft 15 of the diesel engine 11 is connected to one end of the rotating shaft 22 of the motor generator 21 via an engine clutch 17 (for example, a wet multi-plate clutch or the like). Further, the engine body 12 is provided with an engine speed detecting device 41. The engine rotation speed detection device 41 is, for example, a rotation sensor, and outputs a detection signal corresponding to the rotation angle (that is, the crank angle) of the crankshaft 15 to the control device 50. For example, the engine speed detection device 41 generates an output pulse every time the crankshaft 15 rotates 15 degrees, and this output pulse is input to the control device 50. The control device 50 detects the crank angle and the engine speed from the output pulse of the engine speed detection device 41.

Further, an exhaust manifold 12A is connected to the exhaust side of the engine body 12. The upstream side of the exhaust passage 12B (exhaust system) is connected to the downstream side of the exhaust manifold 12A. A catalyst 61 for purifying exhaust gas is provided on the downstream side of the exhaust passage 12B. A temperature detection device 62 is provided near the upstream side of the catalyst 61. The temperature detection device 62 is, for example, a temperature sensor, and outputs a detection signal corresponding to the catalyst temperature of the catalyst 61 to the control device 50.

When the catalyst temperature reaches the active temperature of the catalyst 61, the exhaust gas purification action of the catalyst 61 functions. The catalyst 61 includes, for example, a Selective Catalytic Reduction (SCR) 61A, and is added by a urea water addition valve (not shown) when the catalyst temperature reaches an active temperature, for example, about 250 ° C. to 300 ° C. Detoxify nitrogen oxides (NOx) in the exhaust gas using urea water (reducing agent solution).

As the motor generator 21, a permanent magnet type AC synchronous motor capable of generating electricity is used. The other end of the rotating shaft 22 of the motor generator 21 is connected to the input shaft 32 of the transmission 31 via a motor clutch 18 (for example, a wet multi-plate clutch or the like). The motor generator 21 also has a function of performing cranking instead of a starter motor (not shown) that starts the engine body 12.

Further, the motor generator 21 is provided with a motor generator rotation speed detecting device 42. The motor generator rotation speed detection device 42 is, for example, a rotation sensor, and outputs a detection signal corresponding to the rotation angle of the rotation shaft 22 to the control device 50. For example, the motor generator rotation speed detection device 42 generates an output pulse every time the rotation shaft 22 rotates 5 degrees, and this output pulse is input to the control device 50. The control device 50 detects the motor generator rotation speed from the output pulse of the motor generator rotation speed detection device 42.

For the transmission 31, a semi-automatic transmission (AMT) or an automatic transmission (AT) that automatically shifts to a target shift stage determined based on the operating state of the hybrid vehicle 1 and preset map data is used. There is. The shift operation in the transmission 31 is controlled by the TCM 51, which is a shift control device. The shifting operation is automatically started when the rotation speed (corresponding to the vehicle speed) of the input shaft 32 detected by the TCM 51 reaches the preset shifting rotation speed C. The TCM 51 uses a sensor (not shown) to acquire the rotation speed R of the input shaft 32 as the rotation speed related to the speed change of the transmission 31.

During this shift operation, the motor clutch 18 is engaged and disconnected at each shift, and the diesel engine 11, the motor generator 21 and the transmission 31 are disconnected or coupled. Further, the rotational power shifted by the transmission 31 is transmitted to the differential 35 via the propeller shaft 34 connected to the output shaft 33, and is distributed as a driving force to each of the pair of driving wheels 36 which are the rear wheels.

Further, the propeller shaft 34 is provided with a vehicle speed sensor 53. The vehicle speed sensor 53 is, for example, a rotation sensor, and outputs a detection signal according to the rotation angle of the propeller shaft 34 to the control device 50. For example, the vehicle speed sensor 53 generates an output pulse every time the propeller shaft 34 rotates 5 degrees, and this output pulse is input to the control device 50. The control device 50 detects the vehicle speed from the output pulse of the vehicle speed sensor 53.

The hybrid system 20 includes a motor generator 21, an inverter 23 electrically connected to the motor generator 21, a high voltage battery 24 (battery), a DC / DC converter 25, and a low voltage battery 26. There is. As the high voltage battery 24, a lithium ion battery, a nickel hydrogen battery and the like are preferably exemplified. A lead battery is used as the low voltage battery 26.

The DC / DC converter 25 has a function of controlling the charge / discharge direction and the output voltage between the high voltage battery 24 and the low voltage battery 26. The low-voltage battery 26 also supplies electric power to various vehicle electrical components 27. Various parameters in the hybrid system 20, for example, the current value, the voltage value, the charge rate (SOC), and the like of the high voltage battery 24 are detected by the battery management system (BMS) 28 and output to the control device 50. The charge rate (SOC) indicates the remaining charge amount, and is, for example, the ratio of the current charge amount to the charge amount in the fully charged state expressed by 0 to 100 [%].

The diesel engine 11 and the hybrid system 20 are controlled by the control device 50. Specifically, when the hybrid vehicle 1 starts or accelerates, the hybrid system 20 assists at least a part of the driving force by the motor generator 21 supplied with electric power from the high voltage battery 24. On the other hand, during inertial running and braking / deceleration, the hybrid system 20 generates regenerative power generation by the motor generator 21 and converts excess kinetic energy generated in the propeller shaft 34 and the like into electric power to convert it into the high voltage battery 24. Charge.

Further, in the hybrid vehicle 1, the engine clutch 17 is set to the disconnected state in which the driving force is not transmitted, and the motor clutch 18 is set to the engaged state, so that the motor travels using only the motor generator 21 as the driving source. (EV driving) becomes possible. Normally, the diesel engine 11 is stopped when the motor is running.

The control device (ECU: Electronic Control Unit) 50 is a known one including a CPU, EEPROM, RAM, ROM, a timer, a backup RAM (not shown), and the like. The CPU executes various arithmetic processes based on various programs and various parameters stored in the ROM or EEPROM. Further, the RAM temporarily stores the calculation result of the CPU, the data input from each detection device, and the like, and the EEPROM and the backup RAM are stored, for example, when the diesel engine 11 or the motor generator 21 is stopped. Store the data to be stored.

The control device 50 is electrically connected to each part such as the diesel engine 11, the engine clutch 17, the motor generator 21, the motor clutch 18, the TCM 51, and the battery management system 28 via a signal line. Further, the control device 50 is provided with the accelerator pedal 45, and a detection signal of the accelerator pedal depression amount detecting device 46 for detecting the depression amount (accelerator opening degree) of the accelerator pedal 45 is input. The accelerator pedal depression amount detection device 46 is, for example, an accelerator pedal depression angle sensor. The control device 50 can detect the depression amount (accelerator opening degree) of the accelerator pedal 45 by the driver based on the detection signal from the accelerator pedal depression amount detection device 46.

FIG. 2 shows a motor running mode (EV running mode) in which only the motor generator 21 of the control device 50 is used as a drive source, and a hybrid running mode (HEV running mode) in which the motor generator 21 and the diesel engine 11 are used as drive sources. It is a figure which shows an example of the traveling mode selection map used when making a selection of. As shown in FIG. 2, the control device 50 determines the traveling mode based on the accelerator opening degree input from the accelerator pedal depression amount detecting device 46 and the vehicle speed input from the vehicle speed sensor 53.

Specifically, when the accelerator opening degree and the vehicle speed belong to the hybrid traveling region (HEV traveling region) 65 in which hybrid traveling is performed by using the motor generator 21 and the diesel engine 11 as drive sources, the control device 50 determines. The driving mode is determined to be the hybrid driving mode (HEV driving mode). Further, when the accelerator opening degree and the vehicle speed belong to the motor traveling region (EV traveling region) 66 in which the motor travels using only the motor generator 21 as the drive source, the control device 50 sets the traveling mode to the motor traveling mode (motor traveling mode). EV driving mode) is determined. Then, the control device 50 controls the diesel engine 11, the engine clutch 17, the motor generator 21, the motor clutch 18, and the like according to the determined traveling mode.

To switch between the motor driving mode (EV driving mode) and the hybrid driving mode (HEV driving mode), the control device 50 starts the engine, which is set by the accelerator opening degree set for each vehicle speed shown in FIG. Use a stop line map. The engine start / stop lines are changed according to the charge rate (SOC) of the high voltage battery 24. That is, the engine start line and the engine stop line decrease in the direction in which the accelerator opening degree decreases as the charge rate (SOC) of the high-voltage battery 24 decreases.

Next, in the hybrid vehicle 1 configured as described above, an example of the "catalyst warm-up control process" executed by the control device 50 when shifting from the motor running (EV running) to the hybrid running (HEV running). Will be described with reference to FIGS. 4 to 9. When the catalyst warm-up condition is satisfied, the control device 50 executes the processing procedure of the catalyst warm-up control process shown in FIG. Further, in motor running (EV running), while the diesel engine 11 is stopped, the motor generator 21 is rotationally driven by power supply from the high voltage battery 24, and the engine clutch 17 is disconnected, and the motor clutch 18 is engaged. It is in contact.

Here, the catalyst warm-up condition is whether or not the catalyst temperature detected by the temperature detection device 62 is lower than the active temperature of the catalyst 61 (for example, about 250 ° C. to 300 ° C.) stored in the ROM in advance. Based on the above, it is determined that the catalyst warm-up condition is satisfied when the temperature is lower than the active temperature. The catalyst 61 can exhibit a desired exhaust gas purification ability when the catalyst temperature is equal to or higher than the active temperature stored in the ROM in advance.

As shown in FIG. 4, when the catalyst warm-up condition is satisfied, first, in step S11, the control device 50 requires the required catalyst temperature raising energy for raising the catalyst temperature of the catalyst 61 to the active temperature. Is calculated and stored in the RAM, and then the process proceeds to step S12. Specifically, the control device 50 detects the current catalyst temperature by the temperature detection device 62. Then, the control device 50 calculates the required catalyst temperature rise energy by multiplying the value obtained by subtracting the current catalyst temperature from the active temperature stored in the ROM in advance by the heat capacity of the catalyst 61 and stores it in the RAM.

In step S12, the control device 50 reads out the required catalyst heating energy calculated in step S11 from the RAM. Then, in order to obtain the required catalyst heating energy, the control device 50 calculates the required power generation amount generated by the motor generator 21 when the diesel engine 11 is driven with the engine clutch 17 in contact state. After storing in the RAM, the process proceeds to step S13. In step S13, the control device 50 detects the current charge rate (SOC) of the high voltage battery 24 via the battery management system (BMS) 28 and stores it in the RAM, and then proceeds to step S14.

In step S14, the control device 50 reads the required power generation amount calculated in step S12 from the RAM, and calculates the charge rate ΔSOC that increases when the required power generation amount is charged to the high voltage battery 24. Subsequently, the control device 50 determines whether or not the total charge rate obtained by adding the increasing charge rate ΔSOC to the charge rate (SOC) of the current high-voltage battery 24 is lower than the normal upper limit charge rate (normal upper limit SOC). judge. The normal upper limit charging rate (normal upper limit SOC) is an upper limit charging rate (SOC) that does not cause overcharging when the high-voltage battery 24 is charged, and is stored in the ROM in advance. When the high-voltage battery 24 is, for example, a lithium-ion battery, the normal upper limit charge rate (normal upper limit SOC) is about 80% to 90%.

Then, the total charge rate obtained by adding the charge rate ΔSOC, which increases when the required power generation amount is charged to the high-voltage battery 24, to the charge rate (SOC) of the current high-voltage battery 24 is equal to or higher than the normal upper limit charge rate (normal upper limit SOC). That is, when it is determined that the battery is overcharged (S14: NO), the control device 50 proceeds to step S15.

In step S15, the control device 50 acquires the driver required torque required by the driver from the accelerator opening degree and the vehicle speed from a map (not shown). Then, the control device 50 continues the motor running for a predetermined time (for example, about 1 second to 10 seconds) by supplying power from the high voltage battery 24 and rotationally driving the motor generator 21 with the driver required torque (active EV running mode). , The processing after step S13 is executed again. Therefore, as shown in FIG. 2, the control device 50 indicates the motor traveling region (EV traveling region) 66 in which the motor travels for a predetermined time (for example, about 1 second to 10 seconds) from the normal region shown by the thick solid line. The motor is driven by expanding to the enlarged area indicated by the alternate long and short dash line (active EV driving mode).

On the other hand, the total charge rate obtained by adding the charge rate ΔSOC, which increases when the required power generation amount is charged to the high-voltage battery 24, to the charge rate (SOC) of the current high-voltage battery 24 is higher than the normal upper limit charge rate (normal upper limit SOC). Is also low, that is, when it is determined that overcharging does not occur (S14: YES), the control device 50 proceeds to step S16. In step S16, the control device 50 acquires the driver required torque required by the driver from the accelerator opening degree and the vehicle speed from a map (not shown). Then, the control device 50 adds the charging torque for rotationally driving the motor generator 21 to generate electricity to the driver required torque and stores it in the RAM as the target engine torque, and then proceeds to step S17. The charging torque shall be a value according to the driver's required torque.

In step S17, the control device 50 reads the target engine torque from the RAM, puts the engine clutch 17 and the motor clutch 18 in contact with each other, and keeps the diesel engine 11 at the target engine torque for a predetermined time (for example, about 1 to 10 seconds). It is driven to warm up the catalyst and stops the power supply to the motor generator 21. Then, the control device 50 charges the high-voltage battery 24 with the generated power generated by the motor generator 21, and then proceeds to step S18.

Here, when the control device 50 executes steps S11 to S17 of the catalyst warm-up control process shown in FIG. 4, the charge rate (SOC) of the high-voltage battery 24 is low and the charge rate (SOC) is high. An example of a change in the charge rate of the high-voltage battery 24 in this case will be described with reference to FIG. When the charge rate (SOC) of the high-voltage battery 24 is low, the charge rate ΔSOC, which increases when the required power generation amount is charged to the high-voltage battery 24, is used to charge the high-voltage battery 24 at the start of catalyst warm-up. The case where the total charge rate added to the rate (SOC) is lower than the normal upper limit charge rate (normal upper limit SOC) is shown by a single point chain line.

Further, when the charge rate (SOC) of the high-voltage battery 24 is high, the charge rate ΔSOC that increases when the required power generation amount is charged to the high-voltage battery 24 is used to charge the high-voltage battery 24 at the start of catalyst warm-up. The case where the total charge rate added to the rate (SOC) is equal to or higher than the normal upper limit charge rate (normal upper limit SOC) is shown by a thick solid line. Further, when the charge rate (SOC) of the high-voltage battery 24 is high, after executing the process of step S12 shown in FIG. 4, the processes of steps S13 to S15 are not executed, and the processes after step S16 are executed. An example of the case is shown by a thick broken line.

Specifically, as shown by the alternate long and short dash line in FIG. 5, when the charge rate (SOC) of the high voltage battery 24 is low at the start of the catalyst warm-up of the catalyst 61, the charge rate (SOC) of the high voltage battery 24 is low. ) Increases with the passage of time due to the power generation of the motor generator 21 after the catalyst warm-up control process is started. Further, the engine torque is set to the target engine torque obtained by adding the charging torque to the driver required torque after starting the catalyst warm-up control process. Then, the control device 50 connects the engine clutch 17 and the motor clutch 18, drives the diesel engine 11 with the target engine torque, and rotationally drives the motor generator 21 to generate power. Further, the catalyst temperature of the catalyst 61 is raised by the exhaust gas as the diesel engine 11 is driven by the target engine torque.

Further, as shown by the thick solid line in FIG. 5, when the charge rate (SOC) of the high voltage battery 24 is high at the start of the catalyst warm-up of the catalyst 61, after the catalyst warm-up control process is started, the time T1 That is, the charge rate (SOC) of the high-voltage battery 24 is lower than the normal upper limit charge rate (normal upper limit SOC) even if the charge rate ΔSOC corresponding to the required power generation amount calculated in step S12 is added. Until then, the control device 50 executes the motor running (active EV running mode). Therefore, the engine torque is set to zero after starting the catalyst warm-up control process until the time T1 is reached, that is, the diesel engine 11 is stopped. Further, the catalyst temperature of the catalyst 61 is almost constant and does not rise because the diesel engine 11 is stopped until the time T1 is reached after the catalyst warm-up control process is started.

Then, as shown by the thick solid line in FIG. 5, when the charge rate (SOC) of the high-voltage battery 24 is high, the charge rate (SOC) of the high-voltage battery 24 is the power generation of the motor generator 21 after time T1. Increases over time. Further, the engine torque is set to the target engine torque obtained by adding the charging torque to the driver required torque. Then, the control device 50 connects the engine clutch 17 and the motor clutch 18, drives the diesel engine 11 with the target engine torque, and rotationally drives the motor generator 21 to generate power. Further, the catalyst temperature of the catalyst 61 is raised by the exhaust gas as the diesel engine 11 is driven by the target engine torque after the time T1.

On the other hand, as shown by the thick broken line in FIG. 5, when the charge rate (SOC) of the high voltage battery 24 is high at the start of the catalyst warm-up of the catalyst 61, after executing the process of step S12 shown in FIG. When the processes of steps S16 and subsequent steps are executed without executing the processes of steps S13 to S15, the charge rate (SOC) of the high voltage battery 24 is determined at time T11 after the catalyst warm-up control process is started. Reach the normal upper limit charge rate (normal upper limit SOC).

As a result, after the time T11, the engine torque is set to the driver required torque obtained by subtracting the charging torque from the target engine torque, and the power generation of the high voltage battery 24 is stopped. Therefore, the charge rate (SOC) of the high-voltage battery 24 is maintained at the normal upper limit charge rate (normal upper limit SOC). Further, since the engine exhaust temperature of the engine exhaust gas flowing into the exhaust manifold 12A is lowered by the amount corresponding to the charging torque, the rate of temperature rise of the catalyst temperature of the catalyst 61 is suppressed.

Next, as shown in FIG. 4, in step S18, the control device 50 detects the current catalyst temperature of the catalyst 61 by the temperature detection device 62 and stores it in the RAM. Further, the control device 50 acquires the driver required torque required by the driver from the accelerator opening degree and the vehicle speed from a map (not shown). Then, the control device 50 adds the charging torque for rotationally driving the motor generator 21 to generate electricity to the driver required torque and stores it in the RAM as the target engine torque. Further, the control device 50 detects the vehicle speed from the pulse signal output by the vehicle speed sensor 53, stores the vehicle speed in the RAM, and then proceeds to step S19.

In step S19, the control device 50 reads out the target engine torque and the vehicle speed stored in the RAM in step S18 from the RAM. Then, the control device 50 acquires the engine exhaust temperature of the engine exhaust gas flowing into the exhaust manifold 12A from the equi-exhaust temperature line corresponding to the target engine torque and the vehicle speed of the exhaust temperature map M1 shown in FIG. Remember. Further, the control device 50 reads the vehicle speed stored in the RAM in step S18 from the RAM, acquires the heat radiation amount of the exhaust passage 12B (exhaust system) corresponding to the vehicle speed from the heat dissipation map M2 shown in FIG. 7, and stores the vehicle speed in the RAM. Remember.

Then, the control device 50 reads out the current catalyst temperature of the catalyst 61 stored in the RAM in step S18. Subsequently, the control device 50 sets the exhaust temperature obtained by subtracting the amount of heat radiation from the engine exhaust temperature as the inflow / exhaust temperature when the exhaust gas flows into the catalyst 61, and the current catalyst temperature of the catalyst 61 is set from this inflow / exhaust temperature. Also determines if the temperature is high. That is, it is determined whether or not the catalyst temperature of the catalyst 61 is lowered by the exhaust gas flowing into the catalyst 61. Then, when it is determined that the current catalyst temperature of the catalyst 61 is higher than the inflow / exhaust temperature, that is, the catalyst temperature of the catalyst 61 is lowered by the exhaust gas flowing into the catalyst 61 at a low load. (S19: YES), the control device 50 proceeds to step S20.

In step S20, the control device 50 disengages the engine clutch 17, stops fuel injection by the fuel injection valves 14A to 14D, stops the diesel engine 11, and stops the catalyst warm-up of the catalyst 61. Subsequently, the control device 50 acquires the driver required torque required by the driver from the accelerator opening degree and the vehicle speed from a map (not shown). Then, the control device 50 brings the motor clutch 18 into contact state, supplies power from the high-voltage battery 24, and rotates and drives the motor generator 21 with the driver required torque for a predetermined time (for example, about 1 second to 10 seconds). After continuing (EV traveling mode), the processes after step S18 are executed again.

Therefore, as shown in FIG. 8, when the current catalyst temperature of the catalyst 61 is higher than the inflow / exhaust temperature of the exhaust gas flowing into the catalyst 61 at a low load, the EV running for motor running is performed. The area is apparently expanded from the normal area indicated by the thick solid line to the enlarged area indicated by the thick single point chain line.

On the other hand, when it is determined that the current catalyst temperature of the catalyst 61 is equal to or lower than the inflow / exhaust temperature, that is, the catalyst temperature of the catalyst 61 is raised by the exhaust gas flowing into the catalyst 61 (S19: NO), the control device 50 proceeds to step S21. In step S21, the control device 50 executes the processes of steps S16 to S17 to warm up the catalyst 61 for a predetermined time (for example, about 1 to 10 seconds), and then proceeds to step S22.

In step S22, the control device 50 detects the current catalyst temperature of the catalyst 61 by the temperature detection device 62. Then, the control device 50 reads the active temperature of the catalyst 61 (for example, about 250 ° C. to 300 ° C.) from the ROM, and whether or not the catalyst temperature is equal to or higher than the active temperature, that is, whether or not the catalyst temperature has reached the active temperature. Judge whether or not. Then, when it is determined that the catalyst temperature is lower than the active temperature (S22: NO), the control device 50 again executes the processes after step S18.

For example, as shown by the thick solid line in the upper time chart of FIG. 9, in the control device 50, at each time T11 to T12, T13 to T14, etc., the current catalyst temperature of the catalyst 61 is higher than the inflow / exhaust temperature. If it is determined to be present (S19: YES), motor running (EV running) is performed (S20). On the other hand, when the control device 50 determines that the current catalyst temperature of the catalyst 61 is equal to or lower than the inflow / exhaust temperature at each time T12 to T13, T14 to T15, etc. (S19: NO), the catalyst 61 (S21 to S22: NO). As a result, as shown by the thick solid line in the lower time chart of FIG. 9, it is possible to prevent the catalyst temperature of the catalyst 61 from decreasing when the load is low.

Therefore, when the diesel engine 11 is driven with the target engine torque during the catalyst warm-up of the catalyst 61, the catalyst temperature of the catalyst 61 becomes higher than the inflow and exhaust temperature of the exhaust gas flowing into the catalyst 61. , The control device 50 can stop the diesel engine 11 and switch to motor running (EV running). As a result, it is possible to suppress the catalyst 61 from being cooled by the inflowing exhaust gas, shorten the catalyst warm-up period, and improve fuel efficiency. When the catalyst temperature of the catalyst 61 is equal to or lower than the inflow / exhaust temperature of the exhaust gas flowing into the catalyst 61, the diesel engine 11 can be driven by the target engine torque to raise the temperature of the catalyst 61 by warming up the catalyst. , The catalyst warm-up period can be further shortened, and the fuel efficiency can be further improved.

Further, since the control device 50 controls the diesel engine 11 to be driven by the target engine torque during the catalyst warm-up of the catalyst 61, it is possible to respond to the required torque of the driver while performing the catalyst warm-up of the catalyst 61. At the same time, the motor generator 21 can be driven by the charging torque to generate power, and the high-voltage battery 24 can be charged.

On the other hand, as shown by the broken line in the upper time chart of FIG. 9, when the catalyst warm-up of the catalyst 61 is continued at each time T11 to T12, T13 to T14, etc., that is, when the motor running (EV running) is not performed. As shown by the broken line in the lower time chart of FIG. 9, the catalyst temperature of the catalyst 61 is lowered at the time of low load. Therefore, it is considered that the period of catalyst warm-up until the catalyst temperature of the catalyst 61 reaches the active temperature is extended, and the fuel consumption is deteriorated.

On the other hand, as shown in FIG. 4, when it is determined in step S22 that the catalyst temperature is equal to or higher than the active temperature, that is, when it is determined that the catalyst temperature has reached the active temperature (S22: YES), the control device. 50 ends the process. That is, the control device 50 ends the catalyst warm-up of the catalyst 61.

Therefore, when the catalyst temperature reaches the active temperature of the catalyst 61, the exhaust gas purification action of the catalyst 61 functions. The catalyst 61 includes, for example, a Selective Catalytic Reduction (SCR) 61A, and is added by a urea water addition valve (not shown) when the catalyst temperature reaches an active temperature, for example, about 250 ° C. to 300 ° C. Nitrogen oxides (NOx) in the exhaust gas can be detoxified by using urea water (reducing agent solution).

Here, when the control device 50 executes steps S18 to S22 of the catalyst warm-up control process shown in FIG. 4, the charge rate (SOC) of the high-voltage battery 24 is low and the charge rate (SOC) is high. An example of a change in the charge rate (SOC) of the high-voltage battery 24 in the case will be described with reference to FIG.

As shown by the alternate long and short dash line in FIG. 5, when the charge rate (SOC) of the high voltage battery 24 is low at the start of the catalyst warm-up of the catalyst 61, the catalyst temperature of the catalyst 61 reaches the active temperature at time T2. The catalyst warm-up has been completed. Further, the charge rate (SOC) of the high-voltage battery 24 increases with the passage of time from time T1 until time T2 when the catalyst temperature of the catalyst 61 reaches the active temperature due to the power generation of the motor generator 21. However, the charge rate (SOC) of the high-voltage battery 24 at time T2 is equal to or less than the normal upper limit charge rate (normal upper limit SOC).

Further, the engine torque is set to the target engine torque obtained by adding the charging torque to the driver required torque until the time T2 even after the time T1. Then, the control device 50 connects the engine clutch 17 and the motor clutch 18, drives the diesel engine 11 with the target engine torque, and rotationally drives the motor generator 21 to generate power. On the other hand, after the time T2 when the catalyst warm-up of the catalyst 61 is completed, the engine torque is set to the driver required torque. As a result, the control device 50 controls the diesel engine 11 to be driven by the target engine torque during the catalyst warm-up, so that it is possible to respond to the driver's required torque while performing the catalyst warm-up, and the motor generator. The high-voltage battery 24 can be charged by driving the 21 with a charging torque to generate electricity.

Further, as shown by the thick solid line in FIG. 5, when the charge rate (SOC) of the high voltage battery 24 is high at the start of the catalyst warm-up of the catalyst 61, the catalyst temperature of the catalyst 61 is the active temperature at time T3. Has been reached, and the catalyst warm-up is complete. Therefore, even when the charge rate (SOC) of the high-voltage battery 24 is high at the start of catalyst warm-up of the catalyst 61, the catalyst warm-up period can be shortened and fuel efficiency can be improved.

Further, the charge rate (SOC) of the high-voltage battery 24 increases with the passage of time from time T1 until time T3 when the catalyst temperature of the catalyst 61 reaches the active temperature due to the power generation of the motor generator 21. However, the charge rate (SOC) of the high-voltage battery 24 at time T3 is equal to or less than the normal upper limit charge rate (normal upper limit SOC). Therefore, when the catalyst 61 is warmed up, even if the high-voltage battery 24 is charged with the generated power of the motor generator 21, the high-voltage battery 24 can be reliably avoided from being overcharged.

Further, the engine torque is set to the target engine torque obtained by adding the charging torque to the driver required torque from the time T1 to the time T3. Then, the control device 50 connects the engine clutch 17 and the motor clutch 18, drives the diesel engine 11 with the target engine torque, and rotationally drives the motor generator 21 to generate power. On the other hand, after the time T3 when the catalyst warm-up of the catalyst 61 is completed, the engine torque is set to the driver required torque.

As a result, the control device 50 controls the diesel engine 11 to be driven by the target engine torque during the catalyst warm-up, so that it is possible to respond to the driver's required torque while performing the catalyst warm-up, and the motor generator. The high-voltage battery 24 can be charged by driving the 21 with a charging torque to generate electricity.

On the other hand, as shown by the thick broken line in FIG. 5, when the charge rate (SOC) of the high voltage battery 24 is high at the start of the catalyst warm-up of the catalyst 61, after executing the process of step S12 shown in FIG. When the processes of steps S16 and subsequent steps are executed without executing the processes of steps S13 to S15, the catalyst temperature of the catalyst 61 does not reach the active temperature even at time T3. Therefore, it is considered that the period of catalyst warm-up until the catalyst temperature of the catalyst 61 reaches the active temperature is extended, and the fuel consumption is deteriorated.

Here, the high voltage battery 24 functions as an example of a battery. The battery management system 28 functions as an example of the charge rate acquisition device. The exhaust manifold 12A and the exhaust passage 12B form an example of the exhaust system. The temperature detection device 62 functions as an example of the catalyst temperature detection device. The control device 50 functions as an example of a required power generation amount acquisition unit, an overcharge determination unit, a catalyst warm-up control unit, a motor running control unit, a target engine torque setting unit, and a catalyst temperature determination unit.

The present invention is not limited to the above-described embodiment, and it goes without saying that various improvements, modifications, additions, and deletions can be made without departing from the gist of the present invention. For example, it may be as follows. In the following description, the same reference numerals as the hybrid vehicle 1 and the like according to the embodiment of FIGS. 1 to 9 indicate the same or equivalent parts as the hybrid vehicle 1 and the like according to the embodiment.

(A) For example, the other end of the rotating shaft 22 of the motor generator 21 may be connected to the input shaft 32 of the transmission 31 so that the motor clutch 18 is provided on the input shaft 32 in the transmission 31. Then, the motor clutch 18 transmits the torque of the rotating shaft 22 and the input shaft 32 by engaging with the motor clutch 18, and cuts off the torque transmission by setting the disengaged state so that the neutral state can be set. May be good.

(B) The numerical value used in the description of the embodiment is an example, and is not limited to this numerical value. Further, the above (≧), the following (≦), the larger (>), the less than (<), etc. may or may not include the equal sign.

1 Hybrid vehicle 11 Diesel engine 12A Exhaust manifold 12B Exhaust passage 17 Engine clutch 18 Motor clutch 21 Motor generator 24 High voltage battery 28 Battery management system 31 Transmission 32 Input shaft 34 Propeller shaft 41 Engine rotation detection device 42 Motor generator rotation detection device 50 Control device 53 Vehicle speed sensor 61 Catalyst 61A Selective reduction catalyst 62 Temperature detector 65 Hybrid driving area 66 Motor driving area

Claims (5)

With a diesel engine and motor generator connected via an engine clutch,
A transmission to which an input shaft connected to the motor generator via a motor clutch is connected, and
A battery electrically connected to the motor generator and
A charge rate acquisition device that acquires the charge rate of the battery, and
A catalyst provided in the exhaust system of the diesel engine to purify the exhaust gas,
A catalyst temperature detection device that detects the catalyst temperature of the catalyst, and
The engine clutch, the diesel engine, the motor generator, the motor clutch, the transmission, the charge rate acquisition device, and a control device connected to the catalyst temperature detection device.
With
The control device is
When the diesel engine is driven to warm up the catalyst, the required amount of power generated to raise the catalyst temperature to the active temperature based on the catalyst temperature detected by the catalyst temperature detector. With the required power generation acquisition department to acquire
An overcharge determination unit that determines whether or not the charge rate when the required power generation amount is charged to the battery exceeds the normal upper limit charge rate of the battery.
When it is determined that the charge rate when the required power generation amount is charged to the battery via the overcharge determination unit does not exceed the normal upper limit charge rate of the battery, the engine clutch and the motor clutch The diesel engine is driven to warm up the catalyst to the active temperature, and the power supply to the motor generator is stopped to charge the battery with the generated power generated by the motor generator. The catalyst warm-up control unit that controls
When it is determined that the charge rate when the required power generation amount is charged to the battery via the overcharge determination unit exceeds the normal upper limit charge rate of the battery, the engine clutch is disengaged. Further, with the motor running control unit that controls the motor running in which the motor clutch is brought into contact with the motor clutch and the diesel engine is stopped while the motor generator is rotationally driven by the power supply from the battery for a predetermined time. ,
Have,
The control device is
Whether or not the charge rate when the required power generation amount is charged to the battery through the overcharge determination unit again after the motor running for the predetermined time exceeds the normal upper limit charge rate of the battery. Control to judge,
Hybrid vehicle. In the hybrid vehicle according to claim 1,
An accelerator opening detection device that detects the accelerator opening and
A vehicle speed detection device that detects the vehicle speed and
With
The control device is
Based on the accelerator opening degree and the vehicle speed, the engine clutch and the motor clutch are brought into contact with each other, and a hybrid traveling region traveling with the diesel engine and the motor generator as drive sources and a motor traveling with the motor traveling It has a running mode setting unit that sets the running area and each.
The motor travel control unit
When it is determined that the charge rate when the required power generation amount is charged to the battery via the overcharge determination unit exceeds the normal upper limit charge rate of the battery, the traveling is performed for the predetermined time. The motor traveling area is expanded via the mode setting unit to control the motor traveling.
Hybrid vehicle. In the hybrid vehicle according to claim 1 or 2.
The control device is
It has a target engine torque setting unit that sets a target engine torque required to raise the temperature of the catalyst to the active temperature when the catalyst is warmed up.
The target engine torque includes a driver required torque and a charging torque generated by the motor generator to charge the battery.
The catalyst warm-up control unit controls to drive the diesel engine with the target engine torque.
Hybrid vehicle. In the hybrid vehicle according to any one of claims 1 to 3.
The control device is
It has a catalyst temperature determining unit for determining whether or not the catalyst temperature has reached the active temperature.
When it is determined that the catalyst temperature has reached the active temperature, control is performed so that the catalyst warm-up of the catalyst is terminated.
Hybrid vehicle. In the hybrid vehicle according to any one of claims 1 to 4.
The catalyst comprises a selective reduction catalyst that selectively purifies NOx in the exhaust gas.
Hybrid vehicle.

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