WO2020249991A1

WO2020249991A1 - Vehicle control method and vehicle

Info

Publication number: WO2020249991A1
Application number: PCT/IB2019/000594
Authority: WO
Inventors: 村上浩一; 酒井亮和; 横山仁
Original assignee: 日産自動車株式会社; ルノーエス．ア．エス．
Priority date: 2019-06-13
Filing date: 2019-06-13
Publication date: 2020-12-17

Abstract

An under-floor catalyst (33) comprises an electrically heated catalyst (40), a GPF (41) positioned downstream from the electrically heated catalyst (40), and a downstream catalyst (42) positioned downstream from the GPF (41). When an internal combustion engine (10) stops during travel a vehicle (1) energizes the electrically heated catalyst (40), thereby warming the downstream catalyst (42). Thus, the vehicle (1) does not require energy for rotating the internal combustion engine (10) in order to regenerate the GPF (41). In other words, the vehicle (1) is able to regenerate the GPF (41) while reducing the energy consumption of the internal combustion engine (10).

Description

Vehicle control method and vehicle

The present invention relates to a vehicle control method and a vehicle.

For example, Patent Document 1 discloses a technique for regenerating a catalyst provided in an exhaust passage of an internal combustion engine in a hybrid vehicle capable of transmitting the power of an internal combustion engine and a motor to wheels (driving wheels). The catalyst of Patent Document 1 collects particulate matter in exhaust gas.

However, in Patent Document 1, when the particulate matter collected in the catalyst is burned to regenerate the catalyst, an internal combustion engine is rotated by a motoring operation or the like to supply oxygen to the catalyst. .. Therefore, in Patent Document 1, energy for rotating the internal combustion engine is required to regenerate the catalyst.

In other words, there is room for further improvement when the catalyst that collects particulate matter in the exhaust is regenerated during traveling.

Japanese Unexamined Patent Publication No. 2010-12596

The present invention has an internal combustion engine and an exhaust purification device provided in an exhaust passage of the internal combustion engine. The exhaust gas purification device includes an electric heating catalyst that generates heat when energized, an exhaust fine particle filter that is located on the downstream side of the electric heating catalyst and can collect exhaust fine particles in the exhaust, and a downstream side of the exhaust fine particle filter. It is equipped with a three-way catalyst located in. The exhaust gas purification device keeps the three-way catalyst warm by energizing the electric heating catalyst while the internal combustion engine is stopped while traveling.

As a result, the vehicle does not require the energy to rotate the internal combustion engine for regeneration of the exhaust particulate filter. That is, the vehicle can regenerate the exhaust particulate filter while suppressing the energy consumption of the internal combustion engine.

Further, the vehicle can keep the three-way catalyst warm by utilizing the combustion of the exhaust particulates deposited on the exhaust particulate filter regardless of the temperature of the exhaust particulate filter.

C. An explanatory diagram schematically showing an outline of a vehicle drive system to which the present invention is applied. An explanatory view schematically showing an outline of a system configuration of an internal combustion engine mounted on a vehicle to which the present invention is applied. An explanatory view schematically showing a schematic configuration of an underfloor catalyst as an exhaust gas purification device. Explanatory drawing which showed the change of the integrated value of the power consumption when the 1st heat retention control was carried out, and the change of the integrated value of the power consumption when the 2nd heat retention control was carried out. The characteristic figure which shows the correlation between the accumulation amount S of exhaust fine particles and the combustion time Tp. The flowchart which shows the flow of control of the vehicle in 1st Example. The timing chart when the second heat retention control was carried out in the vehicle in 1st Example. The characteristic figure which shows the correlation of the battery charge state and the EV running time Ts. The flowchart which shows the flow of control of the vehicle in 2nd Example. The flowchart which shows the flow of control of the vehicle in 3rd Example. The explanatory view which schematically showed the schematic structure of the underfloor catalyst in 4th Example. The flowchart which shows the flow of control of the vehicle in 4th Example. The timing chart when the 4th heat retention control was carried out in the vehicle in 4th Example.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an explanatory diagram schematically showing an outline of a drive system of a vehicle 1 to which the present invention is applied. FIG. 2 is an explanatory diagram schematically showing an outline of a system configuration of an internal combustion engine 10 mounted on a vehicle 1 to which the present invention is applied.

The vehicle 1 is, for example, a hybrid vehicle, and has a drive unit 3 for driving the drive wheels 2 and a power generation unit 4 for generating electric power for driving the drive wheels 2.

The drive unit 3 has a drive motor 5 as an electric motor that rotationally drives the drive wheels 2, and a first gear train 6 and a differential gear 7 that transmit the driving force of the drive motor 5 to the drive wheels 2. .. Power is supplied to the drive motor 5 from a battery 8 (not shown) charged with the power generated by the power generation unit 4.

The power generation unit 4 includes a generator 9 that generates electric power to be supplied to the drive motor 5, an internal combustion engine 10 that drives the generator 9, and a second gear train 11 that transmits the rotation of the internal combustion engine 10 to the generator 9. have.

The vehicle 1 of this embodiment is a so-called series hybrid vehicle that does not use the internal combustion engine 10 as power. That is, in the vehicle 1 of this embodiment, the internal combustion engine 10 is dedicated to power generation, and the drive motor 5 drives the drive wheels 2 to travel. In the vehicle 1 of the present embodiment, for example, when the remaining battery level (remaining charge) of the battery 8 becomes low, the internal combustion engine 10 is driven to charge the battery 8 and the generator 9 generates electricity.

The drive motor 5 is a direct drive source for the vehicle 1, and is driven by, for example, AC power from the battery 8. The drive motor 5 includes, for example, a synchronous motor using a permanent magnet in the rotor.

Further, the drive motor 5 functions as a generator when the vehicle 1 is decelerated. That is, the drive motor 5 is a generator motor that can charge the battery 8 using the regenerative energy during vehicle deceleration as electric power.

The first gear train 6 decelerates the rotation of the drive motor 5 and increases the motor torque to secure the running drive torque.

The first gear train 6 is, for example, a gear train by two-stage deceleration, and is a motor shaft 14 having a drive unit first gear 13, and a first idler shaft 17 having a drive unit second gear 15 and a drive unit third gear 16. And have. The motor shaft 14 is a rotation shaft of the drive motor 5.

The drive unit first gear 13 is meshed with the drive unit second gear 15.

The third gear 16 of the drive unit is meshed with the input side gear 18 provided on the input side of the differential gear 7.

The differential gear 7 transmits the drive torque input from the first gear train 6 via the input side gear 18 to the left and

right drive wheels

2 and 2 via the left and

right drive shafts

19 and 19. The differential gear 7 can transmit the same drive torque to the left and

right drive wheels

2 and 2 while allowing a difference in the number of rotations of the left and

right drive wheels

2 and 2.

The generator 9 is composed of, for example, a synchronous motor using a permanent magnet in the rotor. The generator 9 converts the rotational energy generated in the internal combustion engine 10 into electrical energy, and charges, for example, the battery 8. The generator 9 also has a function as an electric motor for driving the internal combustion engine 10, and functions as a starter motor when the internal combustion engine 10 is started. That is, the generator 9 is a generator motor, can supply the generated electric power to the battery 8, and can be rotationally driven by the electric power from the battery 8.

Note that the electric power generated by the generator 9 may be directly supplied to the drive motor 5 instead of charging the battery 8, for example, depending on the operating state. Further, the internal combustion engine 10 may be started by, for example, a dedicated starter motor different from the generator 9.

The second gear train 11 is a gear train that connects the internal combustion engine 10 and the generator 9. The second gear train 11 includes an engine shaft 24 having a power generation unit first gear 23, a second idler shaft 26 having a power generation unit second gear 25, and a generator input shaft 28 having a power generation unit third gear 27. And have.

The second gear train 11 speeds up the rotation speed of the internal combustion engine 10 during power generation operation to transmit the engine torque required for the generator 9. When the generator 9 functions as a starter, the second gear train 11 decelerates the rotation speed of the generator 9 and transmits the motor torque required for the internal combustion engine 10.

The engine shaft 24 rotates synchronously with the crankshaft (not shown) of the internal combustion engine 10. The generator input shaft 28 rotates synchronously with the rotor (not shown) of the generator 9.

The first gear 23 of the power generation unit is meshed with the second gear 25 of the power generation unit. The third gear 27 of the power generation unit is meshed with the second gear 25 of the power generation unit. That is, the power generation unit first gear 23 and the power generation unit third gear 27 are meshed with the power generation unit second gear 25.

The internal combustion engine 10 is, for example, a gasoline engine arranged in an engine room located on the front side of the vehicle 1.

As shown in FIG. 2, a manifold catalyst 32 and an underfloor catalyst 33 are provided in the exhaust passage 31 of the internal combustion engine 10.

Further, the exhaust passage 31 is connected to the secondary air introduction passage 35 that supplies the secondary air (oxygen) sent out from the air pump 34. The secondary air introduction passage 35 is the entrance of the underfloor catalyst 33 and is connected to the exhaust passage 31. That is, the secondary air introduction passage 35 is connected to the exhaust passage 31 at a position downstream of the manifold catalyst 32 and upstream of the underfloor catalyst 33.

The air pump 34 and the secondary air introduction passage 35 correspond to an oxygen supply unit capable of supplying oxygen to the inlet of the EHC 40 described later. That is, the secondary air can be supplied to the upstream side of the EHC 40 described later.

The manifold catalyst 32 is arranged in the engine room and is close to the internal combustion engine 10. The manifold catalyst 32 is composed of, for example, a three-way catalyst.

The three-way catalyst purifies the exhaust gas discharged from the internal combustion engine 10, and when the excess air ratio is approximately "1", that is, when the exhaust air-fuel ratio is approximately the theoretical air-fuel ratio, the inflowing exhaust gas is used. The purification rates of the three components HC, CO, and NOx are all increased.

The underfloor catalyst 33 corresponds to an exhaust gas purification device, and is located on the downstream side of the manifold catalyst 32, for example, at a position such as under the floor of the vehicle 1 relatively far from the engine room of the vehicle 1. .. The underfloor catalyst 33 has a larger capacity than the manifold catalyst 32.

Here, as shown in FIG. 3, the underfloor catalyst 33 includes an electric heating catalyst (EHC) 40 that generates heat when energized, a GPF (Gasoline Particulate Filter) 41 as an exhaust particulate filter (particulate filter), and three. The downstream catalyst 42 made of the original catalyst is connected in series. The electric heating catalyst 40 is located on the upstream side of the GPF 41. The GPF 41 is located on the upstream side of the downstream catalyst 42.

The electric heating catalyst 40 is a catalyst that generates heat when energized. The energization of the electric heating catalyst 40 is controlled by the control unit 51. The source of electric power supplied to the electric heating catalyst 40 is, for example, a battery 8 that supplies electric power to the drive motor 5. The power supply source of the electric power supplied to the electric heating catalyst 40 may be a battery different from the battery 8 that supplies the electric power to the drive motor 5.

The GPF 41 collects PM, which is exhaust fine particles (Particulate Matter) in the exhaust gas discharged from the internal combustion engine 10.

As the GPF 41, for example, a filter having a wall flow honeycomb structure (so-called sealing type) in which a large number of honeycomb-shaped fine passages are formed in a filter material such as cordierite and the ends thereof are alternately closed. Used. The GPF 41 may support a catalyst of the same type as the three-way catalyst so as to have the function of the three-way catalyst.

The underfloor catalyst 33 is provided with a GPF temperature sensor 52 that detects the temperature of the GPF 41 and a GPF differential pressure sensor 53 that detects the front-rear differential pressure of the GPF 41. The detection signals of the GPF temperature sensor 52 and the GPF differential pressure sensor 53 are input to the control unit 51. The GPF temperature sensor 52 corresponds to the exhaust particulate filter temperature detection unit.

The control unit 51 is a well-known digital computer equipped with a CPU, ROM, RAM, and an input / output interface.

The control unit 51 includes an air flow meter 54 that detects the amount of intake air, a crank angle sensor 55 that detects the crank angle of the crankshaft, an accelerator opening sensor 56 that detects the amount of depression of the accelerator pedal, and a temperature of secondary air. The detection signals of the secondary air temperature sensor 57 and various sensors such as the vehicle speed sensor 58 that detects the vehicle speed are input.

The crank angle sensor 55 can detect the engine speed of the internal combustion engine 10.

The control unit 51 calculates the required load of the internal combustion engine 10 (load of the internal combustion engine 10) by using the detected value of the accelerator opening sensor 56.

The control unit 51 controls the internal combustion engine 10 based on the detection signals of various sensors. Further, the control unit 51 controls the drive of the air pump 34 to control the amount of secondary air supplied to the GPF 41.

The internal combustion engine 10 is stopped if the remaining battery level (remaining charge) of the battery 8 is high while the vehicle 1 is running. That is, the underfloor catalyst 33 is mounted on the vehicle 1 having a function of stopping the internal combustion engine 10 during traveling.

Exhaust particles collected in GPF41 can be removed by burning. When the internal combustion engine 10 is stopped during traveling, the control unit 51 drives the air pump 34 to supply secondary air to the upstream side of the electric heating catalyst 40 when exhaust fine particles are accumulated on the GPF 41. , The electric heating catalyst 40 is energized. The amount of secondary air supplied to the electric heating catalyst 40 is set so that at least the exhaust particles deposited on the GPF 41 cause an oxidation reaction (combustion reaction).

That is, when the internal combustion engine 10 is stopped while the control unit 51 is running, if exhaust particles are accumulated on the GPF 41, the exhaust particles accumulated on the GPF 41 are accumulated by energizing the electric heating catalyst 40. It corresponds to a control unit that burns the fine particles and keeps the downstream catalyst 42 warm with the heat of burning the exhaust fine particles.

As a result, in the vehicle 1, the exhaust fine particles deposited on the GPF 41 are burned, and the heat generated by burning the exhaust fine particles can keep the downstream catalyst 42 warm. In other words, the vehicle 1 can regenerate the GPF 41 with the internal combustion engine 10 stopped without rotating the internal combustion engine 10. That is, the vehicle 1 does not need the energy to rotate the internal combustion engine 10 for the regeneration of the GPF 41. Therefore, the vehicle 1 can regenerate the GPF 41 while suppressing the energy consumption of the internal combustion engine 10.

Further, since the vehicle 1 does not need to rotate the internal combustion engine 10 when the GPF 41 is regenerated, the components (for example, hydrocarbon) contained in the oil (lubricating oil) are released to the outside as the internal combustion engine 10 rotates. There is no risk of it.

Then, the vehicle 1 can keep the downstream catalyst 42 warm by utilizing the combustion of the exhaust fine particles deposited on the GPF 41 regardless of the temperature of the GPF 41. That is, the vehicle 1 can suppress the temperature drop while the internal combustion engine 10 is stopped by utilizing the combustion heat of the exhaust fine particles. Therefore, the vehicle 1 can suppress the deterioration of the exhaust gas purification performance when the internal combustion engine 10 is started.

Further, the control unit 51 controls the energization of the electric heating catalyst 40 according to the accumulated amount S of the exhaust fine particles collected in the GPF 41. That is, the control unit 51 selects either the first heat retention control or the second heat retention control according to the accumulated amount S of the exhaust fine particles. The first heat retention control continues until the stopped internal combustion engine 10 restarts. The second heat retention control continues until the stopped internal combustion engine 10 is restarted or the combustion of the exhaust fine particles accumulated on the GPF 41 is completed.

In the first heat retention control, the downstream side catalyst 42 is kept warm with the secondary air heated by the heat of the electric heating catalyst 40.

In the first heat retention control, since a predetermined constant power is continuously supplied to the electric heating catalyst 40 during the control, the power consumption (integrated value) increases as the elapsed time from the start of the control increases.

The amount of electric energy per unit time supplied to the electric heating catalyst 40 during the first heat retention control is set so that the downstream side catalyst 42 can be kept warm by the secondary air heated when passing through the electric heating catalyst 40. ..

In the second heat retention control, the electric heating catalyst 40 is energized until the exhaust fine particles deposited on the GPF 41 start to burn to raise the temperature of the GPF 41, and the downstream catalyst 42 is kept warm by the heat generated by the combustion of the exhaust fine particles.

Immediately after the start of the control, the second heat retention control temporarily supplies a larger electric power to the electric heating catalyst 40 than the first heat retention control, and then does not supply the electric power to the electric heating catalyst 40. Therefore, the elapsed time from the start of the control Regardless, the power consumption (integrated value) is constant.

The amount of electric energy per unit time temporarily supplied to the electric heating catalyst 40 at the start of the second heat retention control is larger than the amount of electric energy per unit time supplied to the electric heating catalyst 40 at the time of the first heat retention control. The temperature of the GPF 41 is set to rise to a temperature at which the fine particles (deposited on the GPF 41) begin to burn.

FIG. 4 shows a characteristic line A (solid line) showing a change in the integrated value of the power consumption of the electric heating catalyst 40 when the first heat retention control is performed, and a consumption of the electric heating catalyst 40 when the second heat retention control is performed. It is explanatory drawing which showed the characteristic line B (broken line) which shows the change of the integrated value of electric power. The characteristic line A is a linear line in which the integrated value of power consumption increases as the control time increases. The characteristic line B rises stepwise (stepped) at the start of control, and thereafter becomes a characteristic line in which the integrated value of power consumption becomes constant regardless of the control time.

As shown in FIG. 4, the magnitude relationship between the power consumption in the first heat retention control and the power consumption in the second heat retention control is reversed with respect to the condition when the characteristic line A and the characteristic line B intersect. The elapsed time from the start of the first and second heat retention controls until the intersection of the characteristic line A and the characteristic line B is defined as the time T1.

When the combustion time Tp of the exhaust particles deposited on the GPF 41 is shorter than the time T1, the power consumption of the electric heating catalyst 40 becomes smaller when the first heat retention control is performed.

When the combustion time Tp of the exhaust particles deposited on the GPF 41 is longer than the time T1, the power consumption of the electric heating catalyst 40 becomes smaller when the second heat retention control is performed.

Therefore, the accumulated amount S of the exhaust particles collected in the GPF 41 is calculated, and the combustion time Tp of the exhaust particles is calculated from the calculated accumulated amount S of the exhaust particles.

The accumulated amount S of the exhaust fine particles collected in the GPF 41 can be calculated by the control unit 51 using, for example, the front-rear differential pressure of the GPF 41 and the gas flow rate (exhaust flow rate) passing through the GPF 41. Further, the accumulated amount S of the exhaust fine particles collected in the GPF 41 controls, for example, a map in which the engine rotation speed and the intake air amount of the internal combustion engine 10 are associated with the accumulated amount S of the exhaust fine particles collected in the GPF 41 in advance. It can also be calculated by preparing it in the unit 51. That is, the control unit 51 corresponds to a deposit amount calculation unit that calculates the deposit amount S of the exhaust fine particles collected in the GPF 41.

FIG. 5 is a characteristic diagram showing the correlation between the accumulated amount S of the exhaust fine particles collected in the GPF 41 and the combustion time Tp thereof. The combustion time Tp of the exhaust fine particles can be calculated from the accumulated amount S of the exhaust fine particles. For example, the control unit 51 stores a map as shown in FIG. 5 in which the accumulated amount S of exhaust particles and the combustion time Tp thereof are associated with each other.

That is, the control unit 51 corresponds to the combustion time calculation unit that calculates the combustion time Tp according to the accumulated amount S of the exhaust fine particles.

The combustion time Tp of the exhaust fine particles is the time when the exhaust fine particles are burned under a predetermined constant condition, and is the time when the exhaust fine particles collected in the GPF 41 are burned so that the downstream catalyst 42 can be kept warm. is there.

When the combustion time Tp corresponding to the accumulated amount S of the exhaust fine particles collected in the GPF 41 is shorter than the time T1, the first heat retention control is performed. That is, when the accumulated amount S of the exhaust particles collected in the GPF 41 is less than the predetermined amount, the downstream catalyst 42 is kept warm by using the secondary air heated by the heat of the electric heating catalyst 40.

When the combustion time Tp corresponding to the accumulated amount S of the exhaust fine particles collected in the GPF 41 is longer than the time T1, the second heat retention control is performed. That is, when the accumulated amount S of the exhaust particles collected in the GPF 41 is equal to or more than a predetermined amount, the electric heating catalyst 40 is energized until the exhaust particles accumulated in the GPF 41 start to burn to raise the temperature of the GPF 41.

That is, the control unit 51 of the first embodiment corresponds to a catalyst control unit that controls energization of the electric heating catalyst 40 according to the accumulated amount S of exhaust fine particles collected in the GPF 41.

The vehicle 1 suppresses the amount of electric power consumed by the electric heating catalyst 40 by changing the heat retention method of the downstream catalyst 42 while the internal combustion engine 10 is stopped according to the accumulated amount S of the exhaust fine particles collected in the GPF 41. At the same time, it is possible to suppress a decrease in exhaust gas purification performance when the internal combustion engine 10 is started.

When the accumulated amount S of the exhaust fine particles in the GPF 41 is small, the combustion time Tp of the exhaust fine particles becomes short, and there is a possibility that a sufficient heat retention time of the downstream catalyst 42 cannot be secured. In that case, the first heat retention control is carried out in which the downstream side catalyst 42 is kept warm by the secondary air heated by the vehicle 1 and the electric heating catalyst 40.

As a result, the vehicle 1 can suppress a decrease in the temperature of the downstream catalyst 42 even when the accumulated amount S of exhaust fine particles in the GPF 41 is small, and can suppress a decrease in the exhaust gas purification performance when the internal combustion engine 10 is started.

When the accumulated amount S of the exhaust fine particles in the GPF 41 is large, it is possible to secure a sufficiently long combustion time Tp of the exhaust fine particles. In that case, the vehicle 1 implements a second heat retention control in which the temperature of the GPF 41 is raised by the electric heating catalyst 40 until the exhaust fine particles deposited on the GPF 41 start to burn.

As a result, the vehicle 1 can keep the downstream catalyst 42 warm by the heat generated by the combustion of the exhaust fine particles.

FIG. 6 is a flowchart showing an example of the control flow of the vehicle 1 in the first embodiment. This routine is repeatedly executed by the control unit 51 at predetermined time intervals (for example, every 10 ms) while the vehicle 1 is traveling.

In step S1, it is determined whether or not the condition for starting the internal combustion engine 10 that is stopped while the vehicle is running is satisfied. If the internal combustion engine 10 is not started in step S1, the process proceeds to step S2. When starting the internal combustion engine 10 in step S1, the process proceeds to step S12.

In step S2, it is determined whether or not the internal combustion engine 10 is stopped. If the internal combustion engine 10 is stopped, the process proceeds from step S2 to step S3. If the internal combustion engine 10 is not stopped, the current routine is terminated.

In step S3, it is determined whether or not the heat retention control (first heat retention control or second heat retention control) is being implemented. If the heat retention control is not performed, the process proceeds from step S3 to step S4. If heat retention control is being implemented, this routine ends.

In step S4, the power consumption characteristic when the first heat retention control is executed is calculated. The power consumption characteristic when the first heat retention control is carried out is synonymous with the characteristic line A which indicates the change in the integrated value of the power consumption of the electric heating catalyst 40 when the first heat retention control is carried out.

In step S5, the power consumption characteristic when the second heat retention control is executed is calculated. The power consumption characteristic when the second heat retention control is carried out is synonymous with the characteristic line B which indicates the change in the integrated value of the power consumption of the electric heating catalyst 40 when the second heat retention control is carried out.

In step S6, the time T1 is calculated. The time T1 is the elapsed time from the start of the first and second heat retention controls until the characteristic line A and the characteristic line B intersect.

In step S7, the accumulated amount S of the exhaust fine particles collected in the GPF 41 is calculated.

In step S8, the combustion time Tp of the exhaust fine particles is calculated using the accumulated amount S. The combustion time Tp is the time until all the exhaust fine particles collected in the GPF 41 are burned under a predetermined constant condition.

In step S9, it is determined whether or not the burning time Tp is smaller than the time T1. If the combustion time Tp is smaller than the time T1, the process proceeds to step S10, the first heat retention control is performed, and the current routine is completed. If the combustion time Tp is the time T1 or more, the process proceeds to step S11, the second heat retention control is performed, and the current routine is completed.

In step S12, it is determined whether or not the heat retention control (first heat retention control or second heat retention control) is being implemented. If the heat retention control is being implemented, the process proceeds to step S13, the heat retention control is finished, and the current routine is finished. If the heat retention control is not implemented, this routine ends.

In the first embodiment, when all the exhaust fine particles collected in the GPF 41 are completely burned while the second heat retention control is being carried out, the second heat retention control is terminated. That is, in the first embodiment, when the second heat retention control is started while the internal combustion engine 10 is stopped, the second heat retention control ends when the exhaust fine particles burn out before the start of the internal combustion engine 10.

In the first embodiment, when the exhaust fine particles collected in the GPF 41 are burned out during the execution of the second heat retention control, the electric heating catalyst 40 is energized until the internal combustion engine 10 is restarted to keep the first heat retention. The downstream catalyst 42 may be kept warm with secondary air as in the control.

FIG. 7 is a timing chart showing an example of the case where the second heat retention control is performed on the vehicle 1 in the first embodiment. In the example shown in FIG. 7, when the exhaust fine particles collected in the GPF 41 are burned out, the electric heating catalyst 40 is energized until the internal combustion engine 10 is restarted.

The time t1 in FIG. 7 is the timing at which the internal combustion engine 10 stops while the vehicle 1 is running. At time t1 in FIG. 7, the electric heating catalyst 40 is started to be energized and the secondary air is started to be supplied.

The time t2 in FIG. 7 is the timing at which the combustion of the exhaust fine particles collected in the GPF 41 starts. At time t2 in FIG. 7, energization of the electric heating catalyst 40 is terminated.

The time t3 in FIG. 7 is the timing at which the exhaust fine particles collected in the GPF 41 are burned out. At time t3 in FIG. 7, energization of the electric heating catalyst 40 is started. At this time, the amount of electric power supplied to the electric heating catalyst 40 is the same as the amount of electric energy supplied to the electric heating catalyst 40 in the first heat retention control.

The time t4 in FIG. 7 is the timing at which the internal combustion engine 10 starts (restarts). At time t4 in FIG. 7, the energization of the electric heating catalyst 40 is terminated and the supply of secondary air is terminated.

The period from time t1 to time t4 in FIG. 7 is a period in which the vehicle 1 is running without starting the internal combustion engine 10.

The characteristic lines P1 and P2 shown by the broken lines in FIG. 7 indicate the energization of the electric heating catalyst 40 and the exhaust fine particles collected by the GPF 41 between the time when the internal combustion engine 10 is stopped and the time when the internal combustion engine 10 is restarted. It shows the temperature change of the GPF 41 (characteristic line P1) and the temperature change of the downstream catalyst 42 (characteristic line P2) when it is not burned.

Hereinafter, other examples of the present invention will be described. The same components as those in the first embodiment described above are designated by the same reference numerals, and duplicate description will be omitted.

The second embodiment of the present invention will be described. The vehicle 1 of the second embodiment has substantially the same configuration as the vehicle 1 of the first embodiment described above. The control unit 51 of the second embodiment controls the energization of the electric heating catalyst 40 according to the battery SOC (State Of Charge), which is the charged state of the battery 8 that supplies electric power to the electric heating catalyst 40. That is, the control unit 51 of the second embodiment selects either the first heat retention control or the second heat retention control according to the state of charge of the battery 8.

The battery SOC is the ratio of the remaining charge to the charge capacity of the battery 8 and can be detected by the control unit 51. That is, the control unit 51 corresponds to a battery SOC detection unit capable of detecting the battery SOC of the battery 8 that supplies electric power to the electric heating catalyst 40.

The system configuration of the internal combustion engine 10 in the second embodiment is the same as that in the first embodiment described above.

With reference to FIG. 4 described above, when the EV running time Ts (running time Ts) that can be run by the battery 8 without starting the internal combustion engine 10 is shorter than the time T1, it is better to perform the first heat retention control. The power consumption of the electric heating catalyst 40 is reduced.

Further, referring to FIG. 4 described above, when the EV travel time Ts that can be traveled by the battery 8 without starting the internal combustion engine 10 is longer than the time T1, it is better to perform the second heat retention control. The power consumption of the heating catalyst 40 is reduced.

Therefore, the battery SOC of the battery 8 is detected, and the EV travel time Ts is calculated from the detected battery SOC of the battery 8.

FIG. 8 is a characteristic diagram showing the correlation between the state of charge of the battery 8 and the EV running time Ts (internal combustion engine stop time). That is, FIG. 8 is a characteristic diagram showing the correlation between the battery SOC of the battery 8 and the EV travel time Ts that can be traveled by the battery SOC without starting the internal combustion engine 10. The EV travel time Ts can be calculated from the battery SOC of the battery 8.

For example, the control unit 51 stores a map as shown in FIG. 8 in which the battery SOC of the battery 8 and the EV travel time Ts are associated with each other.

That is, the control unit 51 corresponds to a travel time calculation unit that calculates the EV travel time Ts according to the battery SOC of the battery 8.

The EV travel time Ts is a travel time during which the vehicle 1 can be driven only by the driving force of the drive motor 5 driven under a predetermined constant condition.

When the EV travel time Ts corresponding to the battery SOC of the battery 8 is shorter than the time T1, the first heat retention control is performed. That is, when the battery SOC of the battery 8 is less than a predetermined amount, the downstream side catalyst 42 is kept warm by using the secondary air heated by the heat of the electric heating catalyst 40.

When the EV travel time Ts corresponding to the battery SOC of the battery 8 is longer than the time T1, the second heat retention control is performed. That is, when the battery SOC of the battery 8 is a predetermined amount or more, the electric heating catalyst 40 is energized to raise the temperature of the GPF 41 until the exhaust particles accumulated on the GPF 41 start to burn.

That is, the control unit 51 of the second embodiment corresponds to the second catalyst control unit that controls the energization of the electric heating catalyst 40 according to the charging state of the battery 8 that supplies electric power to the electric heating catalyst 40.

The vehicle 1 suppresses the amount of electric power consumed by the electric heating catalyst 40 by changing the heat retention method of the three-way catalyst while the internal combustion engine is stopped according to the battery SOC of the battery 8 that supplies electric power to the electric heating catalyst 40. At the same time, it is possible to suppress a decrease in exhaust purification performance when the internal combustion engine is started.

When the battery SOC of the battery 8 that supplies electric power to the electric heating catalyst 40 is low, the running time (EV running time Ts) with the internal combustion engine 10 stopped is relatively short. That is, when the battery SOC of the battery 8 is less than a predetermined amount, the amount of electric power supplied to the electric heating catalyst 40 in order to keep the downstream side catalyst 42 warm with the secondary air is reduced. In that case, the vehicle 1 implements the first heat retention control in which the downstream side catalyst 42 is kept warm with the secondary air heated by the electric heating catalyst 40.

As a result, in the vehicle 1, the temperature drop of the downstream catalyst 42 can be suppressed, and the drop in the exhaust gas purification performance when the internal combustion engine 10 is started can be suppressed.

When the battery SOC of the battery 8 that supplies electric power to the electric heating catalyst 40 is large, the running time (EV running time Ts) with the internal combustion engine 10 stopped becomes relatively long. That is, when the battery SOC of the battery 8 becomes a predetermined amount or more, the amount of electric power supplied to the electric heating catalyst 40 in order to keep the downstream side catalyst 42 warm with the secondary air increases. In that case, the vehicle 1 implements a second heat retention control in which the temperature of the GPF 41 is raised by the electric heating catalyst 40 until the exhaust fine particles deposited on the GPF 41 start to burn.

Also in the second embodiment, the vehicle 1 does not require the energy to rotate the internal combustion engine 10 for the regeneration of the GPF 41. Therefore, the vehicle 1 can regenerate the GPF 41 while suppressing the energy consumption of the internal combustion engine 10.

Further, also in the second embodiment, since the vehicle 1 can keep the downstream catalyst 42 warm by utilizing the combustion of the exhaust fine particles deposited on the GPF 41 regardless of the temperature of the GPF 41, the exhaust gas at the time of starting the internal combustion engine 10 It is possible to suppress the deterioration of purification performance.

FIG. 9 is a flowchart showing an example of the control flow of the vehicle 1 in the second embodiment. This routine is repeatedly executed by the control unit 51 at predetermined time intervals (for example, every 10 ms) while the vehicle 1 is traveling.

In step S21, it is determined whether or not the condition for starting the internal combustion engine 10 that is stopped while the vehicle is running is satisfied. If the internal combustion engine 10 is not started in step S21, the process proceeds to step S22. When starting the internal combustion engine 10 in step S21, the process proceeds to step S32.

In step S22, it is determined whether or not the internal combustion engine 10 is stopped. If the internal combustion engine 10 is stopped, the process proceeds from step S22 to step S23. If the internal combustion engine 10 is not stopped, the current routine is terminated.

In step S23, it is determined whether or not the heat retention control (first heat retention control or second heat retention control) is being implemented. If the heat retention control is not performed, the process proceeds from step S23 to step S24. If heat retention control is being implemented, this routine ends.

In step S24, the power consumption characteristic when the first heat retention control is executed is calculated. The power consumption characteristic when the first heat retention control is carried out is synonymous with the characteristic line A which indicates the change in the integrated value of the power consumption of the electric heating catalyst 40 when the first heat retention control is carried out.

In step S25, the power consumption characteristic when the second heat retention control is executed is calculated. The power consumption characteristic when the second heat retention control is carried out is synonymous with the characteristic line B which indicates the change in the integrated value of the power consumption of the electric heating catalyst 40 when the second heat retention control is carried out.

In step S26, the time T1 is calculated. The time T1 is the elapsed time from the start of the first and second heat retention controls until the characteristic line A and the characteristic line B intersect.

In step S27, the battery SOC of the battery 8 that supplies electric power to the electric heating catalyst 40 is detected.

In step S28, the EV travel time Ts is calculated using the battery SOC. The EV travel time Ts is a time during which the EV travel time Ts can be traveled by the battery SOC of the battery 8 without starting the internal combustion engine 10.

In step S29, it is determined whether or not the EV travel time Ts is smaller than the time T1. If the EV travel time Ts is smaller than the time T1, the process proceeds to step S30, the first heat retention control is performed, and the current routine is completed. If the EV travel time Ts is time T1 or more, the process proceeds to step S31, the second heat retention control is performed, and the current routine is completed.

In step S32, it is determined whether or not the heat retention control (first heat retention control or second heat retention control) is being implemented. When the heat retention control is performed, the process proceeds to step S33, the heat retention control is finished, and the current routine is finished. If the heat retention control is not implemented, this routine ends.

In the second embodiment, when all the exhaust fine particles collected in the GPF 41 are completely burned while the second heat retention control is being carried out, the second heat retention control is terminated. That is, in the second embodiment, when the second heat retention control is started while the internal combustion engine 10 is stopped, the second heat retention control ends when the exhaust fine particles burn out before the start of the internal combustion engine 10.

In the second embodiment, when the exhaust fine particles collected in the GPF 41 are burned out during the execution of the second heat retention control, the electric heating catalyst 40 is energized until the internal combustion engine 10 is restarted to keep the first heat retention. The downstream catalyst 42 may be kept warm with secondary air as in the control.

The third embodiment of the present invention will be described. The vehicle 1 of the third embodiment has substantially the same configuration as the vehicle 1 of the first embodiment described above. The control unit 51 of the third embodiment is charged according to the relationship between the accumulated amount S of the exhaust fine particles collected in the GPF 41 and the charged state (battery SOC) of the battery 8 that supplies electric power to the electric heating catalyst 40. The energization of the heating catalyst 40 is controlled. That is, the control unit 51 of the third embodiment selects either the first heat retention control or the second heat retention control according to the relationship between the accumulated amount S of exhaust fine particles and the charge state of the battery 8.

The system configuration of the internal combustion engine 10 in the third embodiment is the same as that in the first embodiment described above.

When the EV travel time Ts corresponding to the battery SOC of the battery 8 is longer than the time T1 and the combustion time Tp corresponding to the accumulated amount S of the exhaust particles collected in the GPF 41 is longer than the time T1, the second heat retention is performed. Enforce control.

That is, when the battery SOC of the battery 8 is larger than the predetermined amount and the accumulated amount S of the exhaust particles is larger than the predetermined amount, the electric heating catalyst 40 is energized until the exhaust particles accumulated on the GPF 41 start to burn. The temperature of GPF 41 is raised.

When the EV travel time Ts corresponding to the battery SOC of the battery 8 is a length of time T1 or less, or the combustion time Tp corresponding to the accumulated amount S of exhaust particles collected in GPF 41 is a length of time T1 or less, The first heat retention control is carried out.

That is, when the battery SOC of the battery 8 is a predetermined amount or less, or when the accumulated amount S of the exhaust fine particles is a predetermined amount or less, the downstream catalyst uses the secondary air heated by the heat of the electric heating catalyst 40. Keep 42 warm.

That is, the control unit 51 in the third embodiment has the electric heating catalyst 40 according to the accumulated amount S of the exhaust fine particles collected in the GPF 41 and the charged state of the battery 8 that supplies electric power to the electric heating catalyst 40. It corresponds to the third catalyst control unit that controls energization.

The vehicle 1 changes the heat retention method of the three-way catalyst while the internal combustion engine is stopped according to the battery SOC of the battery 8 that supplies power to the electric heating catalyst 40 and the accumulated amount S of the exhaust fine particles collected in the GPF 41. By doing so, it is possible to suppress the deterioration of the exhaust purification performance at the time of starting the internal combustion engine while suppressing the amount of electric power consumed by the electric heating catalyst 40.

In the vehicle 1, when the battery SOC of the battery 8 that supplies power to the electric heating catalyst 40 is larger than the predetermined amount and the accumulated amount S of the exhaust particles collected in the GPF 41 is larger than the predetermined amount, the vehicle 1 is deposited on the exhaust particle filter. The temperature of the exhaust particle filter is raised by the electric heating catalyst 40 until the exhaust particles start to burn. That is, the electric heating catalyst 40 in this case is energized for the purpose of raising the temperature of the GPF 41. As a result, the vehicle 1 can keep the downstream catalyst 42 warm by the heat generated by the combustion of the exhaust fine particles.

In the vehicle 1, when the battery SOC of the battery 8 that supplies power to the electric heating catalyst 40 is a predetermined amount or less, or the accumulated amount S of exhaust fine particles collected in the GPF 41 is a predetermined amount or less, the heat of the electric heating catalyst 40 By keeping the downstream side catalyst 42 warm using the secondary air heated in 1), the temperature decrease of the three-way catalyst can be suppressed, and the decrease of the exhaust gas purification performance at the time of starting the internal combustion engine can be suppressed.

Also in the third embodiment, the vehicle 1 does not require the energy to rotate the internal combustion engine 10 for the regeneration of the GPF 41. Therefore, the vehicle 1 can regenerate the GPF 41 while suppressing the energy consumption of the internal combustion engine 10.

Further, also in the third embodiment, since the vehicle 1 can keep the downstream catalyst 42 warm by utilizing the combustion of the exhaust fine particles deposited on the GPF 41 regardless of the temperature of the GPF 41, the exhaust gas at the time of starting the internal combustion engine 10 It is possible to suppress the deterioration of purification performance.

FIG. 10 is a flowchart showing an example of the control flow of the vehicle 1 in the third embodiment. This routine is repeatedly executed by the control unit 51 at predetermined time intervals (for example, every 10 ms) while the vehicle 1 is traveling.

In step S41, it is determined whether or not the condition for starting the internal combustion engine 10 that is stopped while the vehicle is running is satisfied. If the internal combustion engine 10 is not started in step S41, the process proceeds to step S42. When starting the internal combustion engine 10 in step S41, the process proceeds to step S55.

In step S42, it is determined whether or not the internal combustion engine 10 is stopped. If the internal combustion engine 10 is stopped, the process proceeds from step S42 to step S43. If the internal combustion engine 10 is not stopped, the current routine is terminated.

In step S43, it is determined whether or not the heat retention control (first heat retention control or second heat retention control) is being implemented. If the heat retention control is not performed, the process proceeds from step S43 to step S44. If heat retention control is being implemented, this routine ends.

In step S44, the power consumption characteristic when the first heat retention control is executed is calculated. The power consumption characteristic when the first heat retention control is carried out is synonymous with the characteristic line A which indicates the change in the integrated value of the power consumption of the electric heating catalyst 40 when the first heat retention control is carried out.

In step S45, the power consumption characteristic when the second heat retention control is executed is calculated. The power consumption characteristic when the second heat retention control is carried out is synonymous with the characteristic line B which indicates the change in the integrated value of the power consumption of the electric heating catalyst 40 when the second heat retention control is carried out.

In step S46, the time T1 is calculated. The time T1 is the elapsed time from the start of the first and second heat retention controls until the characteristic line A and the characteristic line B intersect.

In step S47, the accumulated amount S of the exhaust fine particles collected in the GPF 41 is calculated.

In step S48, the battery SOC of the battery 8 that supplies electric power to the electric heating catalyst 40 is detected.

In step S49, the combustion time Tp of the exhaust fine particles is calculated using the accumulated amount S. The combustion time Tp is the time until all the exhaust fine particles collected in the GPF 41 are burned under a predetermined constant condition.

In step S50, the EV travel time Ts is calculated using the battery SOC. The EV travel time Ts is a time during which the EV travel time Ts can be traveled by the battery SOC of the battery 8 without starting the internal combustion engine 10.

In step S51, it is determined whether or not the burning time Tp is larger than the time T1. If the burning time Tp is larger than the time T1, the process proceeds to step S52. If the combustion time Tp is less than or equal to the time T1, the process proceeds to step S54, the first heat retention control is performed, and the current routine is completed.

In step S52, it is determined whether or not the EV travel time Ts is larger than the time T1. If the EV travel time Ts is larger than the time T1, the process proceeds to step S53, the second heat retention control is performed, and the current routine is completed. If the EV travel time Ts is less than or equal to the time T1, the process proceeds to step S54, the first heat retention control is performed, and the current routine is completed.

In step S55, it is determined whether or not the heat retention control (first heat retention control or second heat retention control) is being implemented. When the heat retention control is performed, the process proceeds to step S56, the heat retention control is finished, and the current routine is finished. If the heat retention control is not implemented, this routine ends.

In the third embodiment, when all the exhaust fine particles collected in the GPF 41 are completely burned while the second heat retention control is being carried out, the second heat retention control is terminated. That is, in the third embodiment, when the second heat retention control is started while the internal combustion engine 10 is stopped, the second heat retention control ends when the exhaust fine particles burn out before the start of the internal combustion engine 10.

In the third embodiment, when the exhaust fine particles collected in the GPF 41 are burned out during the execution of the second heat retention control, the electric heating catalyst 40 is energized until the internal combustion engine 10 is restarted to keep the first heat retention. The downstream catalyst 42 may be kept warm with secondary air as in the control.

The fourth embodiment of the present invention will be described. The vehicle 1 of the fourth embodiment has substantially the same configuration as the vehicle 1 of the first embodiment described above. The vehicle 1 in the fourth embodiment includes a second electric heating catalyst 43. That is, as shown in FIG. 11, the underfloor catalyst 33 in the fourth embodiment includes a second electric heating catalyst (second EHC) 43 between the GPF 41 and the downstream catalyst 42.

The second electric heating catalyst 43 is a catalyst that generates heat when energized. The energization of the second electric heating catalyst 43 is controlled by the control unit 51. The power supply source of the power supplied to the second electric heating catalyst 43 is, for example, the battery 8 that supplies power to the drive motor 5. The power supply source of the electric power supplied to the second electric heating catalyst 43 may be a battery different from the battery 8 that supplies the electric power to the drive motor 5.

The control unit 51 of the fourth embodiment controls the energization of the electric heating catalyst 40 and the second electric heating catalyst 43 according to the accumulated amount S of the exhaust fine particles collected in the GPF 41.

That is, the control unit 51 in the fourth embodiment selects either the third heat retention control or the fourth heat retention control according to the accumulated amount S of the exhaust fine particles. The third heat retention control continues until the stopped internal combustion engine 10 restarts. The fourth heat retention control continues until the stopped internal combustion engine 10 restarts or the combustion of the exhaust fine particles accumulated on the GPF 41 is completed.

In the third heat retention control, the downstream side catalyst 42 is kept warm with the secondary air heated by the heat of the second electric heating catalyst 43.

In the third heat retention control, since a predetermined constant power is continuously supplied to the second electric heating catalyst 43 during the control, the power consumption (integrated value) increases as the elapsed time from the start of the control increases.

The amount of electric energy per unit time supplied to the second electric heating catalyst 43 during the third heat retention control is such that the downstream side catalyst 42 can be kept warm by the secondary air heated when passing through the second electric heating catalyst 43. Is set to. In the third heat retention control, the electric heating catalyst 40 located on the upstream side of the GPF 41 is not energized.

In the fourth heat retention control, the electric heating catalyst 40 is energized until the exhaust fine particles deposited on the GPF 41 start to burn to raise the temperature of the GPF 41, and the downstream catalyst 42 is kept warm by the heat generated by the combustion of the exhaust fine particles. In the fourth heat retention control, the second electric heating catalyst 43 located on the downstream side of the GPF 41 is not energized.

Immediately after the start of the control, the fourth heat retention control temporarily supplies a larger electric power to the electric heating catalyst 40 than the third heat retention control, and then does not supply the electric power to the electric heating catalyst 40. Therefore, the elapsed time from the start of the control Regardless, the power consumption (integrated value) is constant.

The amount of electric energy per unit time temporarily supplied to the electric heating catalyst 40 at the start of the fourth heat retention control is larger than the amount of electric energy per unit time supplied to the electric heating catalyst 40 at the time of the third heat retention control. The temperature of the GPF 41 is set to rise to a temperature at which the fine particles (deposited on the GPF 41) begin to burn.

Here, the relationship between the power consumption when the third heat retention control is carried out and the power consumption when the fourth heat retention control is carried out is similar to that of FIG. 4 described above.

That is, the characteristic line showing the change in the integrated value of the power consumption of the second electric heating catalyst 43 when the third heat retention control is performed is a linear straight line in which the integrated value of the power consumption increases as the control time becomes longer. The characteristic line indicating the change in the integrated value of the power consumption of the electric heating catalyst 40 when the fourth heat retention control is performed rises in a step shape (step shape) at the start of the control, and becomes constant regardless of the control time thereafter.

The characteristic line showing the change in the integrated value of the power consumption of the second electric heating catalyst 43 when the third heat retention control is performed, and the change in the integrated value of the power consumption of the electric heating catalyst 40 when the fourth heat retention control is performed. The magnitude relationship between the power consumption in the third heat retention control and the power consumption in the fourth heat retention control is reversed with respect to the condition when the characteristic line indicating the above intersects.

The elapsed time from the start of the third and fourth heat retention controls to the intersection of these characteristic lines is defined as the time T2.

When the combustion time Tp of the exhaust particles accumulated on the GPF 41 is shorter than the time T2, the power consumption can be reduced by performing the third heat retention control.

When the combustion time Tp of the exhaust particles deposited on GPF41 is longer than the time T2, the power consumption can be reduced by performing the fourth heat retention control.

Therefore, in the fourth embodiment, similarly to the first embodiment described above, the accumulated amount S of the exhaust particles collected in the GPF 41 is calculated, and the combustion of the exhaust particles is calculated from the calculated accumulated amount S of the exhaust particles. Calculate the time Tp.

Then, when the combustion time Tp corresponding to the accumulated amount S of the exhaust fine particles collected in the GPF 41 is shorter than the time T2, the third heat retention control is performed. That is, when the accumulated amount S of the exhaust particles collected in the GPF 41 is less than a predetermined amount, the downstream catalyst 42 is kept warm by using the secondary air heated by the heat of the second electric heating catalyst 43.

When the combustion time Tp corresponding to the accumulated amount S of the exhaust fine particles collected in the GPF 41 is a length of the time T2 or more, the fourth heat retention control is performed. That is, when the accumulated amount S of the exhaust particles collected in the GPF 41 is equal to or more than a predetermined amount, the electric heating catalyst 40 is energized until the exhaust particles accumulated in the GPF 41 start to burn to raise the temperature of the GPF 41.

That is, the control unit 51 of the fourth embodiment corresponds to the fourth catalyst control unit that controls the energization of the electric heating catalyst 40 and the second electric heating catalyst 43 according to the accumulated amount S of the exhaust fine particles collected in the GPF 41. To do.

In such a vehicle 1 of the fourth embodiment, it is possible to obtain substantially the same effect as that of the first embodiment described above.

Further, in the vehicle 1 of the fourth embodiment, the amount of electric energy supplied to the second electric heating catalyst 43 during the third heat retention control is supplied to the electric heating catalyst 40 during the first heat retention control described above. It will be less than the amount of electricity per unit time. This is because in the first heat retention control, the heat of the secondary air is taken away by the GPF 41 located between the electric heating catalyst 40 and the downstream catalyst 42.

Therefore, in the vehicle 1 of the fourth embodiment, when the accumulated amount S of the exhaust fine particles collected in the GPF 41 is less than the predetermined amount, the vehicle 1 of the fourth embodiment keeps the downstream catalyst 42 warm with a smaller electric energy than the above-mentioned first embodiment. can do.

FIG. 12 is a flowchart showing an example of the control flow of the vehicle 1 in the fourth embodiment. This routine is repeatedly executed by the control unit 51 at predetermined time intervals (for example, every 10 ms) while the vehicle 1 is traveling.

In step S61, it is determined whether or not the condition for starting the internal combustion engine 10 that is stopped while the vehicle is running is satisfied. If the internal combustion engine 10 is not started in step S61, the process proceeds to step S62. When starting the internal combustion engine 10 in step S61, the process proceeds to step S72.

In step S62, it is determined whether or not the internal combustion engine 10 is stopped. If the internal combustion engine 10 is stopped, the process proceeds from step S62 to step S63. If the internal combustion engine 10 is not stopped, the current routine is terminated.

In step S63, it is determined whether or not the heat retention control (third heat retention control or fourth heat retention control) is being implemented. If the heat retention control is not performed, the process proceeds from step S63 to step S64. If heat retention control is being implemented, this routine ends.

In step S64, the power consumption characteristic when the third heat retention control is executed is calculated. The power consumption characteristic when the third heat retention control is carried out is synonymous with a characteristic line showing a change in the integrated value of the power consumption of the second electric heating catalyst 43 when the third heat retention control is carried out.

In step S65, the power consumption characteristic when the fourth heat retention control is executed is calculated. The power consumption characteristic when the fourth heat retention control is carried out is synonymous with a characteristic line showing a change in the integrated value of the power consumption of the electric heating catalyst 40 when the fourth heat retention control is carried out.

In step S66, the time T2 is calculated. The time T2 is the elapsed time from the start of the third and fourth heat retention controls to the intersection of these characteristic lines.

In step S67, the accumulated amount S of the exhaust fine particles collected in the GPF 41 is calculated.

In step S68, the combustion time Tp of the exhaust fine particles is calculated using the accumulated amount S. The combustion time Tp is the time until all the exhaust fine particles collected in the GPF 41 are burned under a predetermined constant condition.

In step S69, it is determined whether or not the burning time Tp is smaller than the time T2. If the combustion time Tp is smaller than the time T2, the process proceeds to step S70, the third heat retention control is performed, and the current routine is completed. If the combustion time Tp is time T2 or more, the process proceeds to step S71, the fourth heat retention control is performed, and the current routine is completed.

In step S72, it is determined whether or not the heat retention control (third heat retention control or fourth heat retention control) is being implemented. If the heat retention control is being implemented, the process proceeds to step S73, the heat retention control is finished, and the current routine is finished. If the heat retention control is not implemented, this routine ends.

In the fourth embodiment, when all the exhaust fine particles collected in the GPF 41 are completely burned while the fourth heat retention control is being carried out, the fourth heat retention control is terminated. That is, in the fourth embodiment, when the fourth heat retention control is started while the internal combustion engine 10 is stopped, the fourth heat retention control ends when the exhaust fine particles burn out before the start of the internal combustion engine 10.

In the fourth embodiment, when the exhaust fine particles collected in the GPF 41 are burned out during the execution of the fourth heat retention control, the second electric heating catalyst 43 is energized until the internal combustion engine 10 is restarted. 3 The downstream catalyst 42 may be kept warm with secondary air as in the heat retention control.

FIG. 13 is a timing chart showing an example of the case where the fourth heat retention control is performed on the vehicle 1 in the fourth embodiment. In the example shown in FIG. 13, when the exhaust fine particles collected in the GPF 41 are burned out, the second electric heating catalyst 43 is energized until the internal combustion engine 10 is restarted.

The time t1 in FIG. 13 is the timing at which the internal combustion engine 10 stops while the vehicle 1 is traveling. At time t1 in FIG. 13, the electric heating catalyst 40 is started to be energized and the secondary air is started to be supplied.

The time t2 in FIG. 13 is the timing at which the combustion of the exhaust fine particles collected in the GPF 41 starts. At time t2 in FIG. 13, the energization of the electric heating catalyst 40 is terminated.

The time t3 in FIG. 13 is the timing at which the exhaust fine particles collected in the GPF 41 are burned out. At time t3 in FIG. 13, energization of the second electric heating catalyst 43 is started. At this time, the amount of electric power supplied to the second electric heating catalyst 43 is the same as the amount of electric energy supplied to the second electric heating catalyst 43 in the third heat retention control.

After time t3, since there is no heat source on the upstream side of GPF41, the temperature of GPF41 gradually decreases.

The time t4 in FIG. 13 is the timing at which the internal combustion engine 10 starts (restarts). At time t4 in FIG. 13, the energization of the second electric heating catalyst 43 is terminated, and the supply of secondary air is terminated.

The period from time t1 to time t4 in FIG. 13 is a period in which the vehicle 1 is running without starting the internal combustion engine 10.

The characteristic lines P3 and P4 shown by the broken lines in FIG. 13 indicate the energization of the electric heating catalyst 40 and the second electric heating catalyst 43 and the GPF 41 between the time when the internal combustion engine 10 is stopped and the time when the internal combustion engine 10 is restarted. The temperature change of the GPF 41 (characteristic line P3) and the temperature change of the downstream catalyst 42 (characteristic line P4) when the collected exhaust fine particles are not burned are shown.

Although specific examples of the present invention have been described above, the present invention is not limited to the above-mentioned examples, and various modifications can be made without departing from the spirit of the present invention.

For example, the internal combustion engine 10 was a gasoline engine in each of the above-described embodiments, but may be a diesel engine. In this case, a DPF (Diesel Particulate Filter) may be used instead of the GPF 41 as the exhaust particulate filter.

In each of the above-described embodiments, the internal combustion engine 10 is mounted on the series hybrid vehicle, but the present invention is not limited to the application to the series hybrid vehicle, and the drive source is only the parallel hybrid vehicle or the internal combustion engine. It is also applicable to vehicles (non-hybrid vehicles). More specifically, the present invention is applicable to a vehicle having a control to stop an internal combustion engine by a coast stop, a sailing stop, or the like while traveling.

Further, the control unit 51 of the fourth embodiment is charged according to the charging state (battery SOC) of the battery 8 that supplies electric power to the electric heating catalyst 40 instead of the accumulated amount S of the exhaust fine particles collected in the GPF 41. The energization of the heating catalyst 40 may be controlled.

In this case, the control unit 51 performs the third heat retention control when the EV travel time Ts corresponding to the battery SOC of the battery 8 is shorter than the time T2. That is, when the battery SOC of the battery 8 is less than a predetermined amount, the downstream side catalyst 42 is kept warm by using the secondary air heated by the heat of the second electric heating catalyst 43. Then, when the EV travel time Ts corresponding to the battery SOC of the battery 8 is a length of time T2 or more, the control unit 51 performs the fourth heat retention control. That is, when the battery SOC of the battery 8 is a predetermined amount or more, the electric heating catalyst 40 is energized to raise the temperature of the GPF 41 until the exhaust particles accumulated on the GPF 41 start to burn.

Further, the control unit 51 of the fourth embodiment corresponds to the relationship between the accumulated amount S of the exhaust fine particles collected in the GPF 41 and the charged state (battery SOC) of the battery 8 that supplies electric power to the electric heating catalyst 40. The energization of the electric heating catalyst 40 may be controlled.

In this case, the control unit 51 has an EV travel time Ts corresponding to the battery SOC of the battery 8 longer than the time T2, and a combustion time Tp corresponding to the accumulated amount S of exhaust fine particles collected in the GPF 41 is longer than the time T2. If it is too long, the fourth heat retention control is carried out. That is, when the battery SOC of the battery 8 is larger than the predetermined amount and the accumulated amount S of the exhaust particles is larger than the predetermined amount, the electric heating catalyst 40 is energized until the exhaust particles accumulated on the GPF 41 start to burn. The temperature of GPF 41 is raised. The control unit 51 has a length in which the EV travel time Ts corresponding to the battery SOC of the battery 8 is time T2 or less, or a combustion time Tp corresponding to the accumulated amount S of exhaust particles collected in the GPF 41 is time T2 or less. In the case of the length of, the third heat retention control is carried out. That is, when the battery SOC of the battery 8 is a predetermined amount or less, or when the accumulated amount S of the exhaust fine particles is a predetermined amount or less, the secondary air heated by the heat of the second electric heating catalyst 43 is used downstream. The side catalyst 42 is kept warm.

The amount of secondary air supplied to the exhaust particulate filter such as GPF41 is smaller than the amount of air flowing during so-called fuel cutting or motoring, for example.

Each of the above-described embodiments relates to a vehicle control method and a vehicle.

Claims

In a vehicle control method having an internal combustion engine and an exhaust purification device provided in an exhaust passage of the internal combustion engine.
The exhaust gas purification device includes an electric heating catalyst that generates heat when energized, an exhaust fine particle filter that is located on the downstream side of the electric heating catalyst and can collect exhaust fine particles in the exhaust, and a downstream side of the exhaust fine particle filter. With a three-way catalyst located in,
A method for controlling a vehicle that keeps the three-way catalyst warm by energizing the electric heating catalyst while the internal combustion engine is stopped while driving.
The vehicle control method according to claim 1, wherein secondary air can be supplied to the upstream side of the electric heating catalyst.
The vehicle control method according to claim 1 or 2, wherein the energization of the electric heating catalyst is controlled according to the accumulated amount of the exhaust particulates collected in the exhaust particulate filter.
When the accumulated amount of exhaust fine particles collected by the exhaust fine particle filter is less than a predetermined amount, the electric heating catalyst is energized and the secondary air heated by the heat of the electric heating catalyst is used to generate the three elements. The vehicle control method according to claim 3, wherein the catalyst is kept warm.
When the accumulated amount of the exhaust particulates collected in the exhaust particulate filter is equal to or more than a predetermined amount, the electric heating catalyst is energized until the exhaust particulates accumulated in the exhaust particulate filter start to burn, and the exhaust particulate filter is used. The vehicle control method according to claim 3 or 4, wherein the temperature is raised.
The vehicle control method according to claim 1 or 2, wherein the energization of the electric heating catalyst is controlled according to the charging state of the battery that supplies electric power to the electric heating catalyst.
When the battery SOC of the battery that supplies electric power to the electric heating catalyst is less than a predetermined amount, the electric heating catalyst is energized and the secondary air heated by the heat of the electric heating catalyst is used to generate the three elements. The vehicle control method according to claim 6, wherein the catalyst is kept warm.
When the battery SOC of the battery that supplies power to the electric heating catalyst is a predetermined amount or more, the electric heating catalyst is energized until the exhaust fine particles accumulated on the exhaust fine particle filter start to burn, and the exhaust fine particle filter is operated. The vehicle control method according to claim 6 or 7, wherein the temperature is raised.
Claim 1 or 2 that controls energization of the electric heating catalyst according to the relationship between the accumulated amount of exhaust fine particles collected by the exhaust fine particle filter and the state of charge of the battery that supplies electric power to the electric heating catalyst. The vehicle control method described in.
When the battery SOC of the battery that supplies power to the electric heating catalyst is more than a predetermined amount and the accumulated amount of exhaust fine particles collected by the exhaust fine particle filter is less than a predetermined amount, the electric heating catalyst is energized. The vehicle control method according to claim 9, wherein the three-way catalyst is kept warm by using secondary air heated by the heat of the electric heating catalyst.
If the battery SOC of the battery that supplies power to the electric heating catalyst is less than or equal to a predetermined amount, or if the amount of accumulated exhaust particles collected by the exhaust particulate filter is greater than or equal to the predetermined amount, they are deposited on the exhaust particulate filter. The vehicle control method according to claim 9 or 10, wherein the electric heating catalyst is energized to raise the temperature of the exhaust particulate filter until the exhaust particulates start to burn.
The exhaust gas purification device includes a second electric heating catalyst between the exhaust fine particle filter and the three-way catalyst, and when the accumulated amount of exhaust fine particles collected by the exhaust fine particle filter is less than a predetermined amount, The vehicle control according to any one of claims 1 to 11, wherein the second electric heating catalyst is energized and the ternary catalyst is kept warm by using the secondary air heated by the heat of the second electric heating catalyst. Method.
With an internal combustion engine
An electric heating catalyst provided in the exhaust passage of the internal combustion engine and generating heat when energized, an exhaust fine particle filter located downstream of the electric heating catalyst and capable of collecting exhaust fine particles in the exhaust, and the exhaust fine particles. An exhaust gas purification device equipped with a three-way catalyst located on the downstream side of the filter,
A vehicle having an oxygen supply unit capable of supplying oxygen to the electric heating catalyst.
The vehicle according to claim 13, further comprising a control unit that keeps the three-way catalyst warm by energizing the electric heating catalyst while the internal combustion engine is stopped while traveling.