Vehicle exhaust purification device

Abstract

To suppress deterioration of energy efficiency while enabling appropriate regeneration of a particulate filter and securing deceleration feeling.SOLUTION: Fuel cut control for stopping fuel supply from a fuel supply device to a combustion chamber and regeneration control for increasing a temperature of a particulate filter by supplying fuel from the fuel supply device to the combustion chamber so as to introduce unburned fuel to an oxidation catalyst are performed. When both of a fuel cut condition and a regeneration condition are satisfied while an engine body and a wheel are coupled to each other, deceleration regeneration control for increasing power generation amount of a power generator by using a power generation amount change device, prohibiting the fuel cut control and allowing the regeneration control is performed if a filter temperature is lower than a determination temperature, and execution of the deceleration regeneration control is restricted if the filter temperature is the determination temperature or higher.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an exhaust purification device for a vehicle having an engine body in which a combustion chamber is formed, an exhaust passage through which exhaust gas discharged from the engine body flows, a particulate filter disposed in the exhaust passage to collect soot in the exhaust gas, an oxidation catalyst disposed in the exhaust passage upstream of the particulate filter to combust unburned fuel in the exhaust gas, and an accelerator pedal. [Background technology]

[0002] As disclosed in Patent Document 1, there is known a vehicle equipped with a particulate filter that traps soot in exhaust gas emitted from the engine body. In such a vehicle, in order to maintain the soot trapping capacity of the particulate filter, when the amount of trapped soot increases, the soot in the particulate filter is burned and removed from the filter.

[0003] Furthermore, in vehicles equipped with engines such as diesel engines whose exhaust gas temperatures are relatively low, an oxidation catalyst is disposed in the exhaust passage upstream of the particulate filter, and unburned fuel is introduced from the combustion chamber to the oxidation catalyst, and the fuel is burned in the oxidation catalyst to raise the temperature of the exhaust gas, thereby burning the soot in the particulate filter and regenerating it. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-12404 Summary of the Invention [Problem to be solved by the invention]

[0005] In an engine that discharges unburned fuel from the combustion chamber to regenerate the particulate filter as described above, fuel may need to be supplied to the combustion chamber to regenerate the particulate filter even when fuel supply to the combustion chamber is required to be stopped due to deceleration of the vehicle, etc. In this case, a portion of the fuel in the combustion chamber burns, causing the engine to apply positive torque (driving torque) to the wheels, resulting in an insufficient deceleration of the vehicle and an insufficient feeling of deceleration for the driver. To address this issue, a power generator that generates electricity by receiving the rotational force of the wheels can be driven to apply negative torque (braking torque) to the wheels. This configuration ensures a feeling of deceleration and allows engine torque to be regenerated as electric power, thereby suppressing a deterioration in fuel economy. However, if the power generator is driven under conditions with low power generation efficiency, i.e., conditions where the ability to regenerate engine torque is kept low, a deterioration in fuel economy may not be sufficiently suppressed.

[0006] An object of the present invention is to provide an exhaust gas purification device for a vehicle that can suppress a decrease in fuel economy performance while realizing appropriate regeneration of a particulate filter and ensuring a sense of deceleration. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides an exhaust purification device for a vehicle having an exhaust passage through which exhaust gas discharged from a combustion chamber of an engine body mounted on a vehicle flows, a particulate filter disposed in the exhaust passage for trapping soot in the exhaust gas, and an oxidation catalyst disposed in the exhaust passage upstream of the particulate filter for combusting unburned fuel in the exhaust gas, the device comprising: a power generation device for receiving rotational force from wheels to generate electricity; a power generation amount change device capable of changing the amount of electricity generated by the power generation device; a fuel supply device for supplying fuel to the combustion chamber; a soot collection amount detection device for detecting a soot collection amount which is the amount of soot trapped in the particulate filter; a temperature detection device for detecting a filter temperature which is the temperature inside the particulate filter; and a control device for controlling each part of the vehicle including the fuel supply device and the power generation amount change device, wherein the control device performs fuel cut control to stop fuel supply from the fuel supply device to the combustion chamber, and a temperature detection device for detecting a temperature inside the particulate filter so that unburned fuel is introduced into the oxidation catalyst. and a judgment unit that determines whether a fuel cut condition for implementing the fuel cut control is met based on an opening degree of an accelerator pedal provided on the vehicle, determines whether a regeneration condition for implementing the regeneration control is met based on a detection result of the trapped soot amount detection device, and determines whether the filter temperature detected by the temperature detection device is equal to or higher than a predetermined judgment temperature, and when both the fuel cut condition and the regeneration condition are met in a state in which the engine body is connected to the wheels, the fuel injection control unit implements deceleration regeneration control that increases the power generation amount of the power generation device by the power generation amount change device, prohibits the fuel cut control, and permits the regeneration control if the filter temperature is lower than the judgment temperature, and restricts the implementation of the deceleration regeneration control if the filter temperature is higher than the judgment temperature.

[0008] Note that the restriction on the implementation of deceleration regeneration control when the filter temperature is equal to or higher than the judgment temperature means reducing the amount of fuel supplied from the fuel supply device to the combustion chamber so that unburned fuel is introduced into the oxidation catalyst, and the increase in the amount of power generated by the power generator, compared to when the filter temperature is below the judgment temperature (including setting these to zero, thereby prohibiting the above-mentioned fuel supply from the fuel supply device and prohibiting an increase in the amount of power generated).

[0009] In the present invention, when it is determined that the regeneration conditions are met based on the detection results of the soot trap amount detection device, regeneration control is performed to supply fuel from the fuel supply device to the combustion chamber so that unburned fuel is introduced into the oxidation catalyst. Therefore, the unburned fuel can be burned in the oxidation catalyst to increase the temperature of the exhaust gas introduced into the particulate filter, and soot trapped in the particulate filter can be burned and regenerated. Furthermore, even when a fuel cut condition is met that would require a fuel cut to stop fuel supply to the combustion chamber, if the regeneration condition is met, the fuel cut control is prohibited and unburned fuel is supplied to the combustion chamber and the oxidation catalyst. Therefore, the particulate filter can be regenerated at an appropriate time, and its soot trapping ability can be maintained in good condition. Furthermore, when the fuel cut condition and the regeneration condition are met while the engine body and the wheels are connected, the amount of power generated by the generator, which generates electricity using the rotational force of the wheels, is increased, and negative torque (braking torque) is applied from the generator to the wheels. Therefore, the execution of regeneration control (prohibition of fuel cut control) can prevent the deceleration of the vehicle from becoming lower than the deceleration desired by the driver, and engine torque can be regenerated as electric power.

[0010] Moreover, in this configuration, when the filter temperature, which is the temperature inside the particulate filter, is equal to or higher than the judgment temperature, the implementation of deceleration regeneration control (control that increases the power generation amount of the power generation device, prohibits fuel cut control, and allows regeneration control) is restricted, so that the particulate filter can be appropriately regenerated while suppressing a decrease in fuel efficiency.

[0011] Specifically, once the filter temperature reaches or exceeds the threshold temperature, soot can be burned in the particulate filter even if the supply of unburned fuel to the oxidation catalyst is stopped or reduced. Therefore, the particulate filter can be appropriately regenerated even if the execution of deceleration regeneration control is limited to suppress or prohibit fuel supply to the combustion chamber. Furthermore, even under conditions where the engine torque regeneration capability of the power generation device is kept low, fuel supply itself is suppressed or prohibited, so a decrease in fuel economy can be suppressed.

[0012] In the above configuration, preferably, a battery is provided which is charged by the power generation device, and the determination unit determines whether or not the SOC of the battery is equal to or higher than a predetermined determination SOC, and the control device limits the execution of the deceleration regeneration control if the SOC of the battery is equal to or higher than the determination SOC when both the fuel cut condition and the regeneration condition are met with the engine body and wheels connected (claim 2).

[0013] According to this configuration, when the SOC of the battery is higher than or equal to the determined SOC, the execution of deceleration regeneration control is restricted, so that power generation by the power generator can be stopped or reduced to prevent the battery from being overcharged.

[0014] In the above configuration, preferably, when the filter temperature rises to or above the judgment temperature after the start of the deceleration regeneration control, the control device restricts the execution of the deceleration regeneration control until at least one of the regeneration condition and the fuel cut condition is no longer satisfied (claim 3).

[0015] It is known that once the filter temperature reaches or exceeds the judgment temperature, any subsequent decrease in the filter temperature is suppressed and the combustion of soot in the particulate filter continues. Therefore, as described above, if the system is configured so that, when the filter temperature rises to or exceeds the judgment temperature after the start of deceleration regeneration control, the execution of deceleration regeneration control is restricted until at least one of the regeneration condition and the fuel cut condition is no longer satisfied, it is possible to reliably suppress a decrease in fuel economy while regenerating the particulate filter.

[0016] In the above configuration, preferably, when restricting the implementation of the deceleration regeneration control, the control device prohibits control to increase the power generation amount of the power generation device and the regeneration control, and also implements the fuel cut control (claim 4).

[0017] According to this configuration, the supply of fuel to the combustion chamber is stopped, so that the deterioration of fuel economy can be more reliably suppressed. [Effects of the Invention]

[0018] According to the exhaust gas purification device for a vehicle of the present invention, it is possible to suppress a decrease in fuel economy performance while ensuring appropriate regeneration of the particulate filter and ensuring a sense of deceleration. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a block diagram showing the overall configuration of a vehicle to which an exhaust purification device according to the present invention is applied. [Figure 2] FIG. 2 is a system diagram of the engine provided in the vehicle. [Figure 3] FIG. 3 is a functional block diagram showing a control system of the vehicle. [Figure 4] FIG. 4 is a flowchart showing the first half of the control relating to fuel injection and power generation. [Figure 5] FIG. 5 is a flowchart showing the latter half of the control relating to fuel injection and power generation. DETAILED DESCRIPTION OF THE INVENTION

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An exhaust gas purification device for a vehicle according to an embodiment of the present invention will be described in detail below with reference to the drawings.

[0021] (Overall vehicle configuration) 1 is a block diagram showing a schematic configuration of a vehicle 10 to which an exhaust purification device 200 according to this embodiment is applied. The vehicle 10 (exhaust purification device 200) includes an engine 1, a motor generator 21, an automatic transmission 22, a clutch CL1, a differential device 23, wheels 24, an inverter 25, a battery 26, a braking device 80, and a processor 100 (control device). The braking device 80 includes a disc rotor 82 that rotates integrally with the wheels 24, brake pads 83 that sandwich the disc rotor 82, and a brake control unit 81 that includes a master cylinder that applies hydraulic pressure to the brake pads 83 and a control unit that controls the hydraulic pressure. The vehicle 10 also includes an accelerator pedal 91 and a brake pedal 92 that are operated by the driver.

[0022] The engine 1 of this embodiment is a four-stroke diesel engine that runs on diesel fuel. The detailed structure of the engine 1 will be described later.

[0023] The motor generator 21 functions both as a motor and as a power generating device. The motor generator 21 is, for example, a three-phase AC synchronous motor generator. The motor generator 21 generates driving force by receiving a supply of electric power stored in a battery 26. The motor generator 21 also generates electric power by the rotational force transmitted from the wheels 24 when the vehicle 10 decelerates. In this case, a braking force corresponding to the electric power generated by the motor generator 21 acts on the wheels 24. The motor generator 21 corresponds to the "power generating device" in the claims.

[0024] The inverter 25 converts the AC current generated by the motor generator 21 into DC current and charges the battery 26. In addition to this current conversion function, the inverter 25 also has the function of changing the rotation speed, etc., of the motor generator 21, and the output torque and power generation amount of the motor generator 21 are changed by the inverter 25. This inverter 25 corresponds to the "power generation amount change device" in the claims.

[0025] The engine 1 and the motor generator 21 are connected in series via a clutch CL1. The motor generator 21 is connected to the drive shaft of the wheels 24 via an automatic transmission 22 and a differential 23. With this configuration, in the vehicle 10 of this embodiment, both the engine 1 and the motor generator 21 are capable of driving the wheels 24 of the vehicle 10. In other words, the vehicle 10 of this embodiment is a hybrid vehicle that has the engine 1 and the motor generator 21 as drive sources for traveling. The clutch CL1 connects or disconnects the output shaft (crankshaft) of the engine main body 2 and the rotating shaft (rotor shaft) of the motor generator 21.

[0026] The automatic transmission 22 functions to change the speed of rotation of the output shaft of the engine body 2 and the rotating shaft of the motor-generator 21 and output the rotation. The automatic transmission 22 includes an input shaft, multiple planetary gear mechanisms, multiple brake mechanisms, multiple clutch mechanisms, and an output shaft. The automatic transmission 22 switches the transmission path of the rotational force input to the input shaft through the operation of each mechanism, thereby changing the speed of the rotational force and outputting it from the output shaft. The input shaft is connected to the rotating shaft of the motor-generator 21, and the output shaft is connected to the differential 23 directly or indirectly via a drive shaft. The multiple clutch mechanisms of the transmission 6 cooperate to achieve the desired gear position and can therefore be roughly regarded as a single clutch CL2. Therefore, when the clutch CL2 is disengaged, torque transmission between the input shaft and the output shaft is interrupted.

[0027] When both clutches CL1 and CL2 are engaged, the driving force of the engine 1 and the motor generator 21 is transmitted to the wheels 24. At this time, when the motor generator 21 does not generate driving force, that is, when electric power is not supplied to the motor generator 21, only the driving force generated by the engine 1 is transmitted to the wheels 24. When the motor generator 21 operates as a power generating device, that is, when the motor generator 21 generates electric power, a braking force is applied from the motor generator 21 to the wheels 24. On the other hand, when the clutch CL2 is engaged and the clutch CL1 is disengaged, only the driving force generated by the motor generator 21 is transmitted to the wheels 24 via the automatic transmission 22 and the like.

[0028] The battery 26 is a rechargeable secondary battery. For example, a lithium-ion battery or a nickel-metal hydride battery is used as the battery 26. The battery 26 supplies driving power to the motor generator 21 via the inverter 25, and also receives and stores the power generated by the motor generator 21 via the inverter 25. A battery current sensor SN8 is attached to the battery 26 to detect the battery current (the output current from the battery 26 and the input current to the battery 26), which is the current flowing in and out of the battery 26.

[0029] The inverter 25 converts three-phase AC power to DC power and vice versa. Specifically, when the motor generator 21 generates driving force, the inverter 25 converts the DC power stored in the battery 26 into three-phase AC power and supplies it to the motor generator 21. On the other hand, when the motor generator 21 generates three-phase AC power, the inverter 25 converts the three-phase AC power into DC power and supplies it to the battery 26.

[0030] Processor 100 comprehensively controls each part of vehicle 10, such as engine 1, inverter 25 (motor generator 21), automatic transmission 22, and clutch CL1. Processor 100 is configured based on a well-known microcomputer, and includes a CPU (Central Processing Unit) that executes various programs, and memories such as ROM and RAM for storing programs and various data. The functional configuration of processor 100 will be described later with reference to FIG. 3.

[0031] The accelerator pedal 91 is a pedal operated by the driver to change the driving force of the vehicle 10, that is, to change the output of the engine main body 2 and / or the output of the motor generator 21 as a motor. The accelerator pedal 91 is provided with an accelerator position sensor SN6 that detects the accelerator position, which is the amount of depression of the accelerator pedal 91. The brake pedal 92 is a pedal for operating the braking device 80, and is operated by the driver to change the braking force applied to the wheels 24 by the braking device 80. The brake pedal 92 is provided with a brake pedal sensor SN7 that detects the brake depression amount, which is the amount of depression of the brake pedal.

[0032] (Overall engine configuration) 2 is a system diagram showing the overall configuration of the engine 1. The engine 1 includes an engine body 2 that is driven by a supply of fuel containing diesel, an intake passage 30 through which intake air introduced into the engine body 2 flows, an exhaust passage 40 through which exhaust gas discharged from the engine body 2 flows, an exhaust turbo device 60 that is driven by the exhaust gas flowing through the exhaust passage 40, and a high-pressure EGR device 50 and a low-pressure EGR device 70 that recirculate a portion of the exhaust gas flowing through the exhaust passage 40 to the intake passage 30.

[0033] The engine body 2 has a plurality of cylinders 2a arranged in a direction perpendicular to the plane of the paper in Fig. 2. The engine body 2 includes a cylinder block 3, a cylinder head 4, and a plurality of pistons 5. The cylinders 2a are formed by the cylinder block 3 and the cylinder head 4. That is, a plurality of cylindrical spaces corresponding to the plurality of cylinders 2a are formed inside the cylinder block 3, and the cylinder head 4 is attached to the upper surface of the cylinder block 3 so as to close off the cylindrical spaces from above. A piston 5 is housed in each cylinder 2a so as to be able to slide back and forth.

[0034] A combustion chamber C is formed above the piston 5 of each cylinder 2a. Each combustion chamber C is a space defined by the lower surface of the cylinder head 4, the side circumferential surface (cylinder liner) of the cylinder 2a, and the crown surface of the piston 5. The combustion chamber C is supplied with fuel injected from an injector 9, which will be described later. The piston 5 receives the combustion energy of the fuel supplied to the combustion chamber C and reciprocates up and down.

[0035] A crankshaft 7, which is the output shaft of the engine body 2, is provided below the pistons 5 and in the lower part of the cylinder block 3. The crankshaft 7 is connected to the pistons 5 of each cylinder 2a via connecting rods 8, and rotates around its central axis in response to the reciprocating motion (up and down movement) of the pistons 5.

[0036] A crank angle sensor SN1 is attached to the cylinder block 3. The crank angle sensor SN1 detects the crank angle, which is the rotation angle of the crankshaft 7, and the engine speed, which is the rotation speed of the crankshaft 7.

[0037] An injector 9 (fuel supply device) is attached to the cylinder head 4. The injector 9 supplies fuel to the combustion chamber C of each cylinder 2a. The injector 9 is attached to the cylinder head 4 so that its tip is exposed to the combustion chamber C. The tip of the injector 9 is formed with multiple nozzle holes that serve as fuel outlets. The fuel injected from each nozzle hole is burned by self-ignition in the combustion chamber C, which has been made hot and pressurized by the compression action of the piston 5.

[0038] The cylinder head 4 is formed with intake ports 11 and exhaust ports 12. The intake ports 11 connect the combustion chambers C of each cylinder 2a to the intake passage 30. The exhaust ports 12 connect the combustion chambers C of each cylinder 2a to the exhaust passage 40. An intake valve 13 is provided in the intake port 11 of each cylinder 2a, and an exhaust valve 14 is provided in the exhaust port 12 of each cylinder 2a.

[0039] The cylinder head 4 is equipped with an intake valve train 15 and an exhaust valve train 16. The intake valve train 15 drives the intake valve 13 of each cylinder 2a to open and close in conjunction with the rotation of the crankshaft 7. The exhaust valve train 16 drives the exhaust valve 14 of each cylinder 2a to open and close in conjunction with the rotation of the crankshaft 7. The intake valve 13 periodically opens and closes the opening of the intake port 11 on the combustion chamber C side in response to the drive of the intake valve train 15. The exhaust valve 14 periodically opens and closes the opening of the exhaust port 12 on the combustion chamber C side in response to the drive of the exhaust valve train 16.

[0040] The intake passage 30 has an air cleaner 31, a compressor 61 of an exhaust turbo device 60, a throttle valve 33, an intercooler 32, a surge tank 30b, and an intake manifold 30a, which are arranged in this order from the upstream side.

[0041] The air cleaner 31 is a filter that removes foreign matter from the intake air. The compressor 61 is an impeller that rotates to compress and send out (supercharge) the intake air. The throttle valve 33 is a valve that opens and closes the intake passage 30 to change the flow rate of the intake air. The intercooler 32 is a heat exchanger that cools the intake air compressed by the compressor 61. The surge tank 30b is a tank that provides an expanded space for equalizing the amount of intake air introduced into each cylinder 2a. The intake manifold 30a is a component that connects the surge tank 30b to the intake ports 11 of each cylinder 2a, and includes multiple branch pipes that communicate with each intake port 11.

[0042] An air flow sensor SN2 is attached to the intake passage 30. The air flow sensor SN2 is a sensor that detects the flow rate of intake air introduced into the engine body 2. The air flow sensor SN2 is disposed in a portion of the intake passage 30 between the air cleaner 31 and the compressor 61.

[0043] The exhaust passage 40 has an exhaust manifold 40a, a turbine 62 of an exhaust turbo device 60, an oxidation catalyst 41, and a DPF (Diesel Particulate Filter) 42. These are arranged in this order from the upstream side.

[0044] The exhaust manifold 40a is a component connected to the exhaust ports 12 of each cylinder 2a, and includes a plurality of branch pipes that communicate with these exhaust ports 12, and an exhaust manifold where the branch pipes converge. The turbine 62 is an impeller that is rotated by the exhaust gas discharged from the engine body 2. When the turbine 62 rotates, the compressor 61 rotates in conjunction with this, and this supercharges the intake air.

[0045] The oxidation catalyst 41 and the DPF 42 are both devices for purifying exhaust gas. The oxidation catalyst 41 oxidizes and detoxifies HC, CO, and other substances in the exhaust gas through the catalytic action of platinum or other metals. The DPF 42 is a filter for collecting PM (Particulate Matter), including soot, contained in the exhaust gas. The soot collected in the DPF 42 is combusted and removed from the DPF 42 when regeneration control, described below, is performed and the exhaust gas temperature reaches a predetermined temperature or higher.

[0046] A differential pressure sensor SN3 is disposed in the exhaust passage 40 to measure the differential pressure across the DPF 42, i.e., the difference between the pressure immediately upstream of the DPF 42 and the pressure immediately downstream of the DPF 42. A pre-DOC temperature sensor SN4 is disposed in the exhaust passage 40 immediately upstream of the oxidation catalyst 41 (between the turbine 62 and the oxidation catalyst 41) to measure the pre-oxidation catalyst temperature, which is the temperature of the exhaust gas passing through this section. A pre-DPF temperature sensor SN5a is disposed in the exhaust passage 40 immediately upstream of the DPF 42 (between the oxidation catalyst 41 and the DPF 42) to measure the pre-DPF temperature, which is the temperature of the exhaust gas passing through this section. In addition, a post-DPF temperature sensor SN5b is disposed in the exhaust passage 40 immediately downstream of the DPF 42 to measure the post-DPF temperature, which is the temperature of the exhaust gas passing through this section.

[0047] Both the high-pressure EGR device 50 and the low-pressure EGR device 70 are devices that recirculate a portion of the exhaust gas flowing through the exhaust passage 40 to the intake passage 30 as EGR gas.

[0048] The low-pressure EGR device 70 includes a low-pressure EGR passage 71, an EGR cooler 72, and a low-pressure EGR valve 73. The low-pressure EGR passage 71 connects a portion of the exhaust passage 40 downstream of the DPF 42 with a portion of the intake passage 30 upstream of the compressor 61. The EGR cooler 72 cools the EGR gas that is recirculated to the intake passage 30 through the low-pressure EGR passage 71. The low-pressure EGR valve 73 is a valve that adjusts the amount of EGR gas that flows through the low-pressure EGR passage 71.

[0049] The high-pressure EGR device 50 includes a high-pressure EGR passage 51 and a high-pressure EGR valve 53. The high-pressure EGR passage 51 connects a portion of the exhaust passage 40 upstream of the turbine 62 with a portion of the intake passage 30 downstream of the intercooler 32. The high-pressure EGR valve 53 is a valve that adjusts the amount of recirculation of external EGR gas.

[0050] (Vehicle control system) 3 is a functional block diagram showing a control system of vehicle 10. Information detected by various sensors is input to processor 100. For example, information detected by crank angle sensor SN1, air flow sensor SN2, differential pressure sensor SN3, pre-DOC temperature sensor SN4, pre-DPF temperature sensor SN5a, post-DPF temperature sensor SN5b, accelerator position sensor SN6, brake pedal sensor SN7, and battery current sensor SN8, i.e., information such as crank angle, engine speed, intake air flow rate, pressure difference before and after DPF, temperature before DPF, temperature after DPF, accelerator position, brake pedal depression amount, and battery current, is sequentially input to processor 100. Vehicle 10 is also equipped with a vehicle speed sensor SN9 for detecting vehicle speed, and the vehicle speed detected by vehicle speed sensor SN9 is also sequentially input to processor 100.

[0051] The processor 100 controls each part of the vehicle 10 based on input information from each of the sensors SN1 to SN9. The processor 100 is electrically connected to the injector 9, throttle valve 33, high-pressure EGR valve 53, low-pressure EGR valve 73, and inverter 25. The processor 100 outputs control signals generated based on input information from each of the sensors SN1 to SN9 to these devices.

[0052] By executing a predetermined program, the processor 100 operates to functionally include a determination unit 101, an SOC estimation unit 102, a soot collection amount / DPF temperature estimation unit 103, a required torque calculation unit 104, an intake control unit 105, a fuel injection control unit 106, and a regeneration control unit 107.

[0053] The SOC estimation unit 102 estimates the battery SOC, which is the SOC (State Of Charge) of the battery 26. The SOC estimation unit 102 calculates the amount of increase or decrease in the battery SOC per unit time based on the battery current detected by the battery current sensor SN8, and calculates (estimates) the battery SOC by integrating this amount.

[0054] The soot trapped amount / DPF temperature estimation unit 103 estimates the soot trapped amount, which is the amount of soot trapped (accumulated) in the DPF 42, and the DPF temperature (filter temperature), which is the temperature inside the DPF 42. The soot trapped amount / DPF temperature estimation unit 103 calculates (estimates) the soot trapped amount based on the differential pressure before and after the DPF detected by the differential pressure sensor SN3. The soot trapped amount / DPF temperature estimation unit 103 calculates this soot trapped amount so that the greater the differential pressure before and after the DPF, the greater the soot trapped amount. The soot trapped amount / DPF temperature estimation unit 103 calculates (estimates) the temperature inside the DPF 42 based on the pre-DPF temperature detected by the pre-DPF temperature sensor SN5a and the post-DPF temperature detected by the post-DPF temperature sensor SN5b.

[0055] In this embodiment, the amount of trapped soot is calculated (detected) by the differential pressure sensor SN3 and the soot collection amount / DPF temperature estimation unit 103. These differential pressure sensor SN3 and soot collection amount / DPF temperature estimation unit 103 correspond to the "soot collection amount detection device" in the claims, and the amount of trapped soot calculated by the soot collection amount / DPF temperature estimation unit 103 corresponds to the "detection result" in the claims. Also, the DPF temperature (filter temperature), which is the temperature inside the DPF 42, is calculated (detected) by the pre-DPF temperature sensor SN5a, the post-DPF temperature sensor SN5b, and the soot collection amount / DPF temperature estimation unit 103. These pre-DPF temperature sensor SN5a, the post-DPF temperature sensor SN5b, and the soot collection amount / DPF temperature estimation unit 103 correspond to the "temperature detection device" in the claims.

[0056] The determination unit 101 performs determinations necessary for controlling the vehicle 10 .

[0057] The determination unit 101 determines whether a regeneration condition, which is a basic condition for performing regeneration control (described later), is met. The determination unit 101 determines that the regeneration condition is met when the soot collection amount calculated by the soot collection amount / DPF temperature estimation unit 103 exceeds a predetermined first determination collection amount, and determines that the regeneration condition is not met when the soot collection amount falls below a second determination collection amount after the regeneration condition is met. The first determination collection amount and the second determination collection amount are set in advance and stored in the determination unit 101. Note that the second determination collection amount is set to a value smaller than the first determination collection amount. The determination unit 101 also determines whether the DPF temperature calculated by the soot collection amount / DPF temperature estimation unit 103 is equal to or higher than a predetermined determination temperature. This determination is used to determine whether to prohibit regeneration control after regeneration control is started when a fuel cut condition is met, as described later. The determination temperature is the lowest temperature at which soot can be combusted in the DPF 42, and is set in advance and stored in the determination unit 101. The determination temperature is set to, for example, about 600 degrees.

[0058] The determination unit 101 determines whether a fuel cut condition, which is a condition for performing fuel cut control described later, is met. The determination unit 101 determines that the fuel cut condition is met when the accelerator pedal 91 is not depressed, the accelerator opening detected by the accelerator opening sensor SN6 is 0, and the engine speed detected by the crank angle sensor SN1 is equal to or greater than a threshold rotation speed. The determination unit 101 determines that the fuel cut condition is not met when the accelerator opening is greater than 0 and the accelerator pedal 91 is depressed, or when the engine speed is less than the threshold rotation speed. The threshold rotation speed is set in advance and stored in the determination unit 101.

[0059] The determination unit 101 determines whether the battery SOC calculated by the SOC estimation unit 102 is less than the determination SOC. The determination SOC is set in advance and stored in the determination unit 101. For example, the determination SOC is set to a value close to 100% (the SOC when the battery 26 is fully charged). In addition to the above, the determination unit 101 also makes various other determinations, such as whether various flags are 1 or 0, and whether to use the engine 1 or the motor generator 21 as the drive source of the vehicle 10.

[0060] The required torque calculation unit 104 calculates the vehicle required torque, which is the torque required of the vehicle, based on the accelerator opening detected by the accelerator opening sensor SN6 and the vehicle speed detected by the vehicle speed sensor SN9.

[0061] When the driver is depressing accelerator pedal 91 and the accelerator opening is greater than 0, required torque calculation unit 104 calculates the vehicle required torque so that it decreases as the accelerator opening becomes smaller and as the vehicle speed becomes higher. Then, required torque calculation unit 104 calculates required engine torque, which is the engine torque required of engine 1, and required motor torque, which is the motor torque required of motor generator 21, based on the vehicle required torque. Specifically, if engine 1 and motor generator 21 are both used as drive sources for vehicle 10, required torque calculation unit 104 first calculates required motor torque, which is the torque required of motor generator 21, and sets the value obtained by subtracting this required motor torque from the vehicle required torque as the required engine torque. The required motor torque is set so that motor generator 21 is driven under conditions where its drive efficiency is high. In contrast, if only engine 1 is used as the driving source of vehicle 10 (i.e., both clutches CL1 and CL2 are engaged, connecting engine 1 to wheels 24, and motor generator 21 is not operating as a motor), the required torque calculation unit 104 sets the vehicle required torque to the required engine torque, which is the torque required of engine 1.

[0062] On the other hand, when the fuel cut condition is satisfied because the driver is not depressing the accelerator pedal 91 and the accelerator opening is equal to or less than 0, the required torque calculation unit 104 calculates, as the vehicle required torque, a negative torque for realizing the deceleration required of the vehicle 10. In other words, when the fuel cut condition is satisfied, the accelerator pedal 91 is not depressed as described above and deceleration is required of the vehicle 10, and the required torque calculation unit 104 calculates, as the vehicle required torque, a negative torque that corresponds to the deceleration required of the vehicle 10 and is required of the vehicle 10. When the engine 1 is used alone as the drive source of the vehicle 10, the required torque calculation unit 104 sets the calculated negative vehicle required torque as the required engine torque. Hereinafter, the required engine torque (negative engine torque) calculated when the engine 1 is used alone as the drive source of the vehicle 10 and the fuel cut condition is satisfied will be referred to as the deceleration required engine torque.

[0063] The required torque calculation unit 104 also calculates the negative vehicle required torque based on the accelerator opening and the vehicle speed. However, when the fuel cut condition is met, the accelerator opening is equal to or less than 0, and the required torque calculation unit 104 essentially sets the negative vehicle required torque according to the vehicle. Here, it is known that the higher the vehicle speed, the higher the deceleration desired by the driver. Therefore, when the fuel cut condition is met, the required torque calculation unit 104 calculates the negative vehicle required torque so that the absolute value of the negative vehicle required torque becomes larger (the negative amount of the vehicle required torque becomes larger) as the vehicle speed becomes higher. Accordingly, when only the engine 1 is used as the drive source of the vehicle 10, the deceleration required engine torque is calculated so that its absolute value becomes larger as the vehicle speed becomes higher.

[0064] When the engine 1 is used as a drive source for the vehicle 10, the intake control unit 105 calculates the flow rate of intake air to be introduced into the combustion chamber C based on the engine speed and required engine torque detected by the crank angle sensor SN1, and changes the opening of the throttle valve 33 to achieve this. The intake control unit 105 also changes the openings of the low-pressure EGR valve 73 and the high-pressure EGR valve 53 based on the engine speed, required engine torque, etc.

[0065] The fuel injection control unit 106 controls the injector 9. The injector 9 is configured to be able to perform two types of injection: normal injection, in which fuel is injected into the combustion chamber C to obtain engine torque, at a timing when almost all of the injected fuel is burned in the combustion chamber C, and post injection, in which fuel is injected at a timing later than the normal injection, so that most of the injected fuel is not burned in the combustion chamber C but is led to the exhaust passage 40 as unburned and introduced into the oxidation catalyst 41.

[0066] During normal operation, the fuel injection control unit 106 performs only normal injection. The fuel injection control unit 106 sets the injection amount (amount of fuel injected into the combustion chamber C by normal injection) and injection timing (start timing of normal injection) of normal injection based on the required engine torque and engine speed, and controls the injector 9 so that these are achieved.

[0067] On the other hand, the fuel injection control unit 106 performs regeneration control to perform post-injection when the regeneration conditions are met. As will be described later, regeneration control (post-injection) is basically performed when the regeneration conditions are met, but it is prohibited under certain conditions even when the regeneration conditions are met.

[0068] The regeneration control (post-injection) is control (injection) for regenerating the DPF 42, that is, for burning the soot trapped in the DPF 42 and removing it from the DPF 42. As described above, the oxidation catalyst 41 capable of oxidizing HC and the like is provided upstream of the DPF 42. Therefore, when post-injection is performed and unburned fuel is discharged into the exhaust passage 40, this unburned fuel is oxidized by the oxidation catalyst 41. As a result, the temperature of the exhaust gas discharged from the oxidation catalyst 41 and introduced into the DPF 42 rises, and the soot is burned and removed within the DPF 42.

[0069] When the regeneration conditions are met, the fuel injection control unit 106 first sets a basic value of the post injection amount based on the engine load, i.e., the required engine torque, and the engine speed. Here, if the required engine torque is less than 0 due to the fuel cut condition being met, the fuel injection control unit 106 sets the basic value based only on the engine speed. In detail, the higher the engine speed, the greater the flow rate of exhaust gas, making it easier for the oxidation catalyst 41 to cool, that is, making it more difficult for the temperature to rise. Therefore, the higher the engine speed, the greater the basic value set by the fuel injection control unit 106.

[0070] Next, the fuel injection control unit 106 corrects the basic value so that the post injection amount increases as the temperature of the exhaust gas upstream of the DPF 42 decreases. Specifically, the fuel injection control unit 106 calculates a first correction amount so that the first correction amount increases as the temperature before the oxidation catalyst measured by the temperature before the DOC sensor SN4 decreases. The fuel injection control unit 106 also calculates a second correction amount so that the second correction amount increases as the temperature before the DPF measured by the temperature before the DPF sensor SN5a decreases. Then, the fuel injection control unit 106 sets the post injection amount to the sum of the basic value, the first correction amount, and the second correction amount.

[0071] When the regeneration conditions are met, the fuel injection control unit 106 causes the injector 9 to inject fuel in the post-injection amount set as described above at a preset timing.

[0072] If all of the fuel supplied to the combustion chamber C by post-injection could be introduced into the oxidation catalyst 41 in an unburned state, the temperature inside the DPF 42 could be efficiently increased. However, if post-injection is performed at a timing when the temperature and pressure inside the combustion chamber C are excessively low, oil dilution may occur. In other words, there is a risk that the fuel will not vaporize but will adhere to the wall surface of the combustion chamber C and pass through the gap between the piston 5 and the cylinder 2a and be mixed into the engine oil. For this reason, the injection timing of post-injection is set to the timing when some of the fuel supplied to the combustion chamber C by post-injection will be burned inside the combustion chamber C.

[0073] Furthermore, when the fuel cut condition is satisfied, the fuel injection control unit 106 executes fuel cut control to prohibit fuel injection from the injector 9. In the fuel cut control, both normal injection and post injection are stopped. As will be described later, the fuel cut control is basically executed when the fuel cut condition is satisfied, but it can be prohibited under certain conditions even when the fuel cut condition is satisfied.

[0074] When the motor generator 21 is used as a power generation device, the regeneration control unit 107 sets a target power generation amount, which is a target value for the power generation amount of the motor generator 21, and controls the inverter 25 so that the power generation amount of the motor generator 21 becomes this target power generation amount.

[0075] When the brake pedal sensor SN7 detects that the brake pedal 92 has been depressed, the regeneration control unit 107 sets the basic target power generation amount, which is a basic value of the target power generation amount, to an amount greater than 0 based on the vehicle speed detected by the vehicle speed sensor SN9, the battery SOC calculated by the SOC estimation unit 102, etc. Note that when the brake pedal 92 is not depressed, the basic target power generation amount is set to 0.

[0076] Here, as described above, a portion of the fuel supplied to the combustion chamber C by post-injection is combusted in the combustion chamber C. Therefore, if regeneration control is performed when the fuel cut condition is met, the engine 1 applies a torque to the wheels 24 (driving torque, i.e., positive torque) to drive the wheels 24, even though deceleration of the vehicle 10 is required and application of a torque to brake the wheels 24 (braking torque, i.e., negative torque) is required. Therefore, when regeneration control is performed under the fuel cut condition, the regeneration control unit 107 sets the target power generation amount to an amount that is greater than the basic power generation amount, which is the sum of the basic power generation amount and the power generation increase amount, and applies a braking torque (negative torque) to the wheels 24 by increasing the power generation amount of the motor generator 21.

[0077] In this way, the processor 100 is capable of prohibiting fuel cut control and performing regeneration control, and also performing deceleration regeneration control, which is control for increasing the amount of power generated by the motor generator 21 above the basic target power generation amount.

[0078] Specifically, the regeneration control unit 107 first calculates the regeneration torque, which is the engine torque generated by the post-injection, based on the post-injection amount set by the fuel injection control unit 106. The regeneration control unit 107 calculates this so that the regeneration torque increases as the post-injection amount increases. Next, the regeneration control unit 107 sets the power generation increase amount based on the deviation between the deceleration request engine torque calculated by the required torque calculation unit 104 and the regeneration torque. The regeneration control unit 107 calculates this so that the power generation increase amount increases as the value obtained by subtracting the deceleration request engine torque from the regeneration torque increases. In detail, the power generation increase amount is set to an amount that, if the motor generator 21 generates power by this power generation increase amount, will cause the engine 1 to generate an inverse torque equal to the value obtained by subtracting the deceleration request engine torque from the regeneration torque, thereby offsetting the excess engine torque relative to the deceleration request engine torque generated by the regeneration control.

[0079] As described above, by performing deceleration regeneration control, an appropriate braking torque can be applied to the wheels 24 while performing post-injection (while performing regeneration control), and it is possible to regenerate the particulate filter 42 and achieve the required engine torque for deceleration, i.e., the deceleration required of the vehicle 10. Furthermore, by being able to regenerate engine torque as electric power, it is possible to suppress a decrease in fuel economy performance due to the performance of post-injection. However, if the motor generator 21 must be driven as a power generating device under conditions of low power generation efficiency, it is not possible to sufficiently suppress a decrease in fuel economy performance because the engine torque cannot be sufficiently regenerated as electric power.

[0080] In response to this, the inventors of the present application have found that when both the regeneration condition and the fuel cut condition are satisfied, once the temperature of the particulate filter 42 rises above the judgment temperature, the temperature inside the particulate filter 42 can be maintained near the judgment temperature, at least for the period until the fuel cut condition is no longer satisfied, even if post-injection (regeneration control) is subsequently stopped. This is thought to be because, once the temperature inside the particulate filter 42 rises above the judgment temperature and soot combustion begins inside the particulate filter 42, the heat of reaction suppresses a decrease in the temperature of the particulate filter 42, and the time during which the fuel cut condition is continuously satisfied is relatively short. Specifically, as described above, the fuel cut condition is satisfied when the engine speed is equal to or higher than the judgment speed. Therefore, the time during which the fuel cut condition is continuously satisfied is kept to be equal to or shorter than the time from when the accelerator pedal 91 is released until the engine speed drops to the judgment speed.

[0081] Based on the above findings, in this embodiment, when both the regeneration condition and the fuel cut condition are met, if the temperature of the particulate filter 42 rises to or above the judgment temperature after the deceleration regeneration control is started, the execution of the deceleration regeneration control is restricted. Specifically, in this embodiment, when both the regeneration condition and the fuel cut condition are met, if the temperature of the particulate filter 42 rises to or above the judgment temperature after the deceleration regeneration control is started, the deceleration regeneration control is prohibited, the regeneration control and the power generation amount increase control are prohibited, and the fuel cut control is implemented.

[0082] Specifically, after the start of deceleration regeneration control, if the DPF temperature calculated by the soot trapped amount / DPF temperature estimation unit 103 becomes equal to or higher than the judgment temperature, the processor 100 (fuel injection control unit 106) stops post injection in addition to normal injection, prohibits regeneration control, and performs fuel cut control. Also, after the start of deceleration regeneration control, if the DPF temperature calculated by the soot trapped amount / DPF temperature estimation unit 103 becomes equal to or higher than the judgment temperature, the processor 100 (regeneration control unit 107) sets the target power generation amount to the basic target power generation amount.

[0083] In addition to the above-mentioned controls, the processor 100 also performs various other controls, such as output control of the motor generator 21 when the motor generator 21 is used as a motor.

[0084] (Control Flow) When the engine 1 is used as a driving source for the vehicle 10, both clutches CL1 and CL2 are engaged to connect the engine 1 to the wheels 24, and the motor generator 21 is not operating as a motor, the control of fuel injection and power generation performed by the processor 100 will be explained using the flowcharts of Figures 4 and 5.

[0085] When the control starts, the processor 100 acquires various pieces of information detected by the sensors SN1 to SN9 (step S1).

[0086] Next, the processor 100 (required torque calculation unit 104) calculates the required engine torque based on the accelerator opening (step S2). As described above, when the fuel cut condition is met, the negative engine torque (deceleration required engine torque) for realizing the deceleration required for the vehicle 10 is calculated as the required engine torque.

[0087] Next, the processor 100 calculates the amount of trapped soot and the battery SOC (step S2). Specifically, the processor 100 (soot trapped amount / DPF temperature estimator 103) calculates the amount of trapped soot, which is the amount of soot trapped in the DPF 42, based on the differential pressure across the DPF 42, and the processor 100 (SOC estimator 102) calculates the battery SOC based on the battery current. The processor 100 (regeneration controller 107) also calculates the basic target power generation amount (step S3). As described above, when the brake pedal 92 is not depressed, the basic target power generation amount is set to 0, and when the brake pedal 92 is depressed, the basic target power generation amount is set to an amount greater than 0.

[0088] Subsequently, the processor 100 (determination unit 101) determines whether the regeneration condition is satisfied (step S5). The processor 100 makes this determination based on a comparison of the soot collection amount calculated in step S3 with the first determination collection amount and the second determination collection amount.

[0089] If it is determined that the regeneration condition is not satisfied (if the determination in step S5 is NO), the processor 100 (determination unit 101) determines whether the fuel cut condition is satisfied (step S20). The processor 100 makes this determination based on the accelerator opening and the engine speed as described above.

[0090] If it is determined that neither the regeneration condition nor the fuel cut condition is satisfied (if the determination in step S20 is NO), the processor 100 (fuel injection control unit 106) performs only normal injection without performing post-injection (step S21). On the other hand, if it is determined that the fuel cut condition is satisfied when the regeneration condition is not satisfied (if the determination in step S20 is YES), the processor 100 (fuel injection control unit 106) performs fuel cut control to stop the injection of fuel from the injector 9 into the combustion chamber C (step S22). In other words, the processor 100 stops both normal injection and post-injection.

[0091] After steps S21 and S22, the processor 100 sets the determination flag to 0 (step S23).

[0092] The determination flag indicates whether deceleration regeneration control is to be performed when both the fuel cutoff condition and the regeneration condition are satisfied. The determination flag is set to 1 when the DPF temperature becomes equal to or higher than the determination temperature after the deceleration regeneration control is started, and is set to 0 when the conditions for performing deceleration regeneration control, excluding the DPF temperature condition, are not satisfied. In detail, the determination flag is switched to 0 when at least one of the fuel cutoff condition, the regeneration condition, and the condition that the battery SOC is less than the determination SOC (described later) is not satisfied.

[0093] After step S23, the processor 100 (regeneration control unit 107) sets the basic target power generation amount calculated in step S3 as the target power generation amount, and controls the inverter 25 to cause the motor generator 21 to generate power equivalent to this target power generation amount, i.e., the basic target power generation amount (step S42). Note that if the target power generation amount (basic target power generation amount) is 0, power generation by the motor generator 21 is stopped. After step S24, the process returns to step S1.

[0094] Returning to step S5, if it is determined that the regeneration condition is met (if the determination in step S5 is YES), the processor 100 (fuel injection control unit 106) calculates the post injection amount (step S6). As described above, the processor 100 calculates the post injection amount based on the amount of trapped soot calculated in step S3.

[0095] Next, the processor 100 (determination unit 101) determines whether or not the fuel cut condition is satisfied, similarly to step S20 (step S7). That is, the processor 100 determines whether or not the fuel cut condition is satisfied when the regeneration condition is satisfied. If this determination is NO, that is, if it is determined that the fuel cut condition is not satisfied when the regeneration condition is satisfied, the processor 100 (fuel injection control unit 106) performs regeneration control and performs normal injection and post injection (step S30). Next, the processor 100 proceeds to step S23, similarly to when the regeneration condition is not satisfied, and sets the determination flag to 0. Then, the processor 100 proceeds to step S42, where the processor 100 (regeneration control unit 107) controls the inverter 25 as described above to have the motor generator 21 generate power equivalent to the basic target power generation amount, and then returns to step S1.

[0096] On the other hand, if the determination in step S7 is YES and both the regeneration condition and the fuel cut condition are met, the processor 100 (determination unit 101) determines whether the battery SOC calculated in step S5 is less than the determination SOC (step S8).

[0097] If the determination in step S8 is NO, and both the regeneration condition and the fuel cut condition are satisfied and the battery SOC is equal to or greater than the determination SOC, the processor 100 sets the determination flag to 0 (step S40). The processor 100 also prohibits the implementation of regeneration control and permits the implementation of fuel cut control. As a result, the processor 100 (fuel injection control unit 106) implements fuel cut control to stop both normal injection and post injection (step S41). The processor 100 (regeneration control unit 107) also proceeds to step S42, where it controls the inverter 25 as described above to cause the motor generator 21 to generate power equivalent to the basic target power generation amount, and then returns to step S1.

[0098] Returning to step S8, if the determination in step S8 is YES, that is, both the regeneration condition and the fuel cut condition are satisfied and the battery SOC is less than the determination SOC, the processor 100 (determination unit 101) determines whether the determination flag is 0 (step S9).

[0099] If the determination in step S9 is NO, both the regeneration condition and the fuel cut condition are met, the battery SOC is less than the determination SOC, and the determination flag is 1, the processor 100 proceeds to step S41 to perform fuel cut and stop both normal injection and post injection. The processor 100 also proceeds to step S42 to set the target power generation amount to a basic target power generation amount and control the inverter 25 to have the motor generator 21 generate power equivalent to this target power generation amount, i.e., the basic target power generation amount.

[0100] On the other hand, if the determination in step S9 is YES, both the regeneration condition and the fuel cut condition are met, the battery SOC is less than the determination SOC, and the determination flag is 0, the processor 100 performs deceleration regeneration control. That is, the processor 100 prohibits fuel cut control, performs regeneration control, and increases the amount of power generated by the motor generator 21 by the amount of power generation increase.

[0101] Specifically, the processor 100 (regeneration control unit 107) calculates the regeneration torque (step S10). As described above, the processor 100 calculates the regeneration torque based on the post-injection amount calculated in step S6. Subsequently, the processor 100 (regeneration control unit 107) calculates the power generation increase amount (step S11). As described above, the processor 100 calculates the power generation increase amount based on the deviation between the regeneration torque calculated in step S9 and the required engine torque (deceleration required engine torque) calculated in step S1. Subsequently, the processor 100 (fuel injection control unit 106) performs post-injection while stopping normal injection (step S12). At this time, the processor 100 (fuel injection control unit 106) injects fuel by the post-injection amount calculated in step S9 from the injector 9 into the combustion chamber C. In addition, the processor 100 (regeneration control unit 107) sets the target power generation amount to the sum of the basic target power generation amount calculated in step S3 and the power generation increase amount calculated in step S10, and controls the inverter 25 to cause the motor generator 21 to generate power equivalent to this target power generation amount (step S13).

[0102] After step S13, the processor 100 (determination unit 101) determines whether the DPF temperature is equal to or higher than the determination temperature (step S14). That is, the processor 100 (determination unit 101) determines whether the DPF temperature has risen to the determination temperature after starting deceleration regeneration control including the processes of steps S9 to S13. If the determination in step S14 is NO, meaning that the DPF temperature is lower than the determination temperature and has not risen to the determination temperature, the processor 100 ends the process and returns to step S1. On the other hand, if the determination in step S14 is YES, meaning that the DPF temperature is equal to or higher than the determination temperature and has risen to the determination temperature after starting deceleration regeneration control, the processor 100 sets the determination flag to 1 (step S15) and ends the process (returns to step S1). Here, when the determination flag becomes 1 as the DPF temperature becomes equal to or higher than the determination temperature, even if all of the conditions of the regeneration condition, the fuel cut condition, and the battery SOC being less than the determination SOC are met, the determination in step S8 becomes NO, and as described above, fuel cut is performed (step S41), the power generation amount of the motor generator 21 is set to the basic target power generation amount (step S42), and the deceleration regeneration control is stopped (prohibited from being performed).

[0103] (effect, etc.) As described above, in the exhaust gas purification device 200 of the vehicle 10 according to the above embodiment, it is determined that the regeneration conditions are met when the soot trapping amount, which is the amount of soot trapped in the DPF 42, exceeds a predetermined first determination trapping amount. Then, when the regeneration conditions are met, basically, post injection is performed and regeneration control is executed in which unburned fuel is introduced into the oxidation catalyst 41. Therefore, when a large amount of soot is trapped in the particulate filter 42, the unburned fuel is burned in the oxidation catalyst 41 to increase the temperature of the exhaust gas introduced into the particulate filter 42, thereby making it possible to burn and remove a large amount of soot trapped in the particulate filter 42 and to appropriately regenerate the particulate filter 42.

[0104] Furthermore, when both the fuel cut condition and the regeneration condition are satisfied with both clutches CL1 and CL2 engaged and the engine 1 and the wheels 24 connected to each other, the deceleration regeneration control is started. That is, the fuel cut control is prohibited and the regeneration control is started, and the amount of power generated by the motor generator 21 is increased by the power generation increase amount from the basic target power generation amount, which is the amount of power generated in normal times (when both the fuel cut condition and the regeneration condition are satisfied with the engine 1 and the wheels 24 connected to each other, and if the regeneration control is not performed), and a braking torque (negative torque) is applied to the wheels 24. Therefore, the temperature inside the particulate filter 42 is reliably increased by performing the regeneration control (post injection) to appropriately regenerate the particulate filter 42, and the increase in engine torque accompanying the performance of the regeneration control is offset by the power generation, so that the deceleration of the vehicle 10 approaches the deceleration desired by the driver, that is, it is possible to provide the driver with an appropriate deceleration feeling, and to regenerate the engine torque as electric power.

[0105] Moreover, after the deceleration regeneration control is started, if the filter temperature, which is the temperature inside the particulate filter 42, becomes equal to or higher than the judgment temperature, the deceleration regeneration control is stopped (prohibited from being implemented). That is, the regeneration control is stopped, fuel cut control is started, and an increase in the amount of power generated by the motor generator 21 is stopped. As a result, the implementation time of the deceleration regeneration control is shortened while the particulate filter 42 is regenerated, making it possible to provide an appropriate deceleration feel and suppress a decrease in fuel economy performance.

[0106] Specifically, as described above, once the filter temperature reaches or exceeds the threshold temperature, the combustion of soot in the particulate filter 42 is maintained even if the supply of unburned fuel to the oxidation catalyst 41 is stopped. As a result, the particulate filter 42 can be regenerated even if the regeneration control is stopped once the filter temperature reaches or exceeds the threshold temperature. In addition, an appropriate deceleration feeling can be provided by starting fuel cut control in conjunction with the stopping of regeneration control. Furthermore, by stopping post-injection, it is possible to suppress a decrease in fuel economy performance that would be caused by post-injection under conditions where power generation efficiency is low and engine torque cannot be sufficiently regenerated by the motor generator 21.

[0107] Furthermore, in the above embodiment, even when both the fuel cutoff condition and the regeneration condition are satisfied, if the battery SOC is equal to or higher than the determination SOC, the deceleration regeneration control is prohibited, and the regeneration control and the control for increasing the power generation amount of the motor-generator 21 by the power generation increase amount are prohibited, and the fuel cutoff control is performed. This prevents the battery 26 from being overcharged, and also prevents a decrease in deceleration. Specifically, by prohibiting the control for increasing the power generation amount of the motor-generator 21, the battery SOC from being equal to or higher than the determination SOC. Furthermore, by prohibiting the regeneration control, it is possible to prevent the engine 2 from applying drive-side torque to the wheels 24 in a state where the power generation amount of the motor-generator 21 is not increased, that is, in a state where the braking-side torque applied from the motor-generator 21 to the wheels 24 is not increased, and thus it is possible to prevent a decrease in deceleration of the vehicle 10.

[0108] (Variation) In the above embodiment, the deceleration regeneration control is started when both the fuel cut condition and the regeneration condition are satisfied, and thereafter, once the filter temperature rises above the judgment temperature, the deceleration regeneration control is prohibited regardless of the filter temperature until the fuel cut condition or the regeneration condition is not satisfied, and the control to increase the power generation amount of the motor generator 21 and the regeneration control are prohibited and the fuel cut control are performed. However, instead of this, the deceleration regeneration control may be always performed as long as the filter temperature is below the judgment temperature when both the fuel cut condition and the regeneration condition are satisfied. In other words, the deceleration regeneration control may be performed as long as the filter temperature drops below the judgment temperature even after the filter temperature has risen once.

[0109] In the above embodiment, the case where deceleration regeneration control is prohibited once the filter temperature rises above the judgment temperature when both the fuel cut condition and the regeneration condition are met has been described, but it is also possible to configure the system so that deceleration regeneration control continues even after the filter temperature rises above the judgment temperature, while reducing the increase in the post-injection amount and the amount of power generation compared to when the filter temperature rises above the judgment temperature. Note that even in the configuration where deceleration regeneration control is always performed when both the fuel cut condition and the regeneration condition are met and the filter temperature is below the judgment temperature, when the filter temperature is above the judgment temperature when both the fuel cut condition and the regeneration condition are met, the implementation of the deceleration regeneration control may be limited by reducing the increase in the post-injection amount and the amount of power generation rather than prohibiting the deceleration regeneration control.

[0110] In the above embodiment, the deceleration regeneration control is prohibited when the battery SOC is equal to or higher than the determination SOC, but the deceleration regeneration control may be performed regardless of the battery SOC. In other words, in the above embodiment, the determination in step S8 may be omitted.

[0111] The specific configuration of engine 1 is not limited to the above. Furthermore, vehicle 10 is not limited to a hybrid vehicle, and may be a vehicle that has only engine body 2 as a drive source for wheels 24 and is equipped with a power generation device that has only power generation function, rather than a motor generator.

[0112] Furthermore, the specific calculation procedure for the post injection amount and the specific calculation procedure for the deceleration required engine torque are not limited to those described above. [Explanation of symbols]

[0113] 1 engine 2 Engine body 9 Injector (fuel supply device) 10 vehicles 21 Motor generator (power generating device) 24 wheels 25 Inverter (power generation change device) 26 Battery 42 DPF (Particulate Filter) 91 Accelerator pedal 100 Processor (controller) 101 Judgment section 103 Soot collection amount estimation unit (soot collection amount detection device, temperature detection device) 104 Required engine torque calculation unit 106 Fuel injection control unit 107 Regeneration control unit SN3 Differential pressure sensor (soot collection amount detection device) SN4 DPF front temperature sensor (temperature detection device) SN5 DPF Post Temperature Sensor (Temperature Detection Device)

Claims

1. An exhaust gas purification device for a vehicle includes an exhaust passage through which exhaust gas discharged from a combustion chamber of an engine body mounted on a vehicle flows, a particulate filter disposed in the exhaust passage to collect soot in the exhaust gas, and an oxidation catalyst disposed in the exhaust passage upstream of the particulate filter to combust unburned fuel in the exhaust gas, a power generation device that generates electricity by receiving rotational force from the wheels; a power generation amount changing device that can change the power generation amount of the power generation device; a fuel supply device for supplying fuel to the combustion chamber; a soot collection amount detection device that detects a soot collection amount, which is the amount of soot collected in the particulate filter; a temperature detection device that detects a filter temperature, which is the temperature inside the particulate filter; a control device that controls each part of the vehicle including the fuel supply device and the power generation amount change device; The control device a fuel injection control unit that performs a fuel cut control that stops the supply of fuel from the fuel supply device to the combustion chamber, and a regeneration control that raises the temperature of the particulate filter by supplying fuel from the fuel supply device to the combustion chamber so that unburned fuel is introduced into the oxidation catalyst; a determination unit that determines whether a fuel cut condition for executing the fuel cut control is satisfied based on an opening degree of an accelerator pedal provided in the vehicle, determines whether a regeneration condition for executing the regeneration control is satisfied based on a detection result of the soot collection amount detection device, and determines whether the filter temperature detected by the temperature detection device is equal to or higher than a predetermined determination temperature, When the engine body is connected to wheels and both the fuel cut condition and the regeneration condition are satisfied, the fuel injection control unit, if the filter temperature is below the judgment temperature, performs deceleration regeneration control to increase the power generation amount of the power generation device using the power generation amount change device, prohibit the fuel cut control, and permit the regeneration control, and, if the filter temperature is above the judgment temperature, restricts the execution of the deceleration regeneration control.

2. The exhaust gas purification device for a vehicle according to claim 1, a battery charged by the power generation device; the determination unit determines whether the SOC of the battery is equal to or greater than a predetermined determination SOC; the control device limits the execution of the deceleration regeneration control if the SOC of the battery is equal to or higher than the determination SOC when both the fuel cut condition and the regeneration condition are satisfied with the engine body and wheels connected.

3. 3. The exhaust gas purification device for a vehicle according to claim 1, the control device, when the filter temperature rises to or above the judgment temperature after the start of the deceleration regeneration control, restricts execution of the deceleration regeneration control until at least one of the regeneration condition and the fuel cut condition is no longer satisfied.

4. The exhaust gas purification device for a vehicle according to any one of claims 1 to 3, The exhaust gas purification device for a vehicle, characterized in that, when restricting the implementation of the deceleration regeneration control, the control device prohibits control to increase the amount of power generated by the power generation device and the regeneration control, and implements the fuel cut control.

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