JP6550012B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device, and more particularly to a vehicle control device capable of achieving both improvement in fuel efficiency by inertial running of a vehicle such as an automobile and part protection by optimum exhaust catalyst management of a purification device provided in an exhaust system.

  In order to improve the fuel efficiency of vehicles such as automobiles, the transmission gear is neutral while traveling, or the engine and transmission are connected to release the clutch that transmits the power of the engine to the wheels. There has been proposed a technology for suppressing the fuel injection amount of the engine by performing the inertia running by moving the vehicle in an idle state or stopping the engine and traveling.

  On the other hand, exhaust gas emitted from a gasoline engine is generally subjected to an oxidation-reduction reaction by a three-way catalyst provided in an exhaust pipe, replaced with a harmless substance, and released to the atmosphere. The three-way catalyst is activated when the temperature is equal to or higher than a certain temperature, and the exhaust gas can be purified most efficiently. This active state is maintained by the heat generated when the mixture of air (intake air) and fuel is burned in the engine. Therefore, when measures are taken to reduce the fuel injection amount by suppressing the engine output as described above, the heat generated when the air-fuel mixture is burned by the engine is also reduced, so the activation state of the three-way catalyst is lost. And there is a concern that exhaust gas purification will not be properly performed.

  In order to solve such a problem, according to Patent Document 1, in a vehicle equipped with a diesel engine (diesel vehicle), the catalyst is used when performing inertia running with the engine being idled or stopped during running. Monitoring the temperature of the vehicle and setting the catalyst temperature that permits the idle running or the engine stop inertia running, and prohibits the transition to each coasting running mode when the temperature of the catalyst is outside the set catalyst temperature range Technology has been proposed.

  Further, in Patent Document 1, the catalyst temperature range which permits the execution of the inertia running mode by stopping the engine is set narrower than the catalyst temperature range which permits the execution of the inertia running mode in which the engine is in the idle state. Measures have been taken to prevent the catalyst temperature from dropping excessively in the coasting mode.

JP, 2014-92102, A

  By the way, there is a direct injection system as a technology for improving the fuel efficiency of a gasoline engine.

  A port injection method found in a conventional gasoline engine is a method in which fuel injection is performed from a fuel injection device (injector) upstream of an intake port before it enters an engine cylinder (cylinder), and a sufficiently vaporized mixture is While the fuel can be completely burned, it is difficult to finely adjust the fuel injection amount.

  On the other hand, the direct injection injection system is a method of performing direct fuel injection into the engine cylinder, and it is possible to adjust the fuel injection amount more finely than the port injection method, and is advantageous for achieving fuel saving .

  However, in the direct injection injection system described above, it is more difficult to mix the fuel and air (intake air) sufficiently than in the port injection method, and the fuel is transferred to the combustion stroke without being sufficiently vaporized. And particulate matter (PM: Particulate Matter) easily occur. Therefore, in the direct injection gasoline engine using the direct injection system, further purification of exhaust gas is required while achieving fuel saving.

  To meet such requirements, gasoline particulate filters (GPF) similar to diesel particulate filters (DPF) applied to diesel engines, in addition to conventional three-way catalysts, are used in gasoline engine exhaust systems. It is conceivable to remove the PM of the exhaust gas emitted from the gasoline engine by adopting a configuration in which a Gasoline Particulate Filter is attached.

  In consideration of achieving both fuel efficiency and efficiency improvement of an exhaust gas purification device (three-way catalyst and GPF) in a vehicle equipped with an exhaust system configured by combining such a three-way catalyst and GPF, Patent Document 1 discloses , The temperature conditions of the catalyst in the implementation of the inertia running of the diesel vehicle equipped with the DPF are described, and it is considered that the condition is insufficient in the configuration provided with the exhaust system by the combination of the three-way catalyst and the GPF .

  More specifically, in the DPF of a known diesel engine, regeneration control is performed to burn the PM by raising the temperature of the DPF when the amount of accumulated PM accumulated exceeds a predetermined value. In the GPF of a gasoline engine, as with this DPF, regeneration control is required when the PM deposition amount increases, but in the exhaust system where the three-way catalyst and the GPF simultaneously exist as described above, the three-way catalyst It is necessary to consider that the regeneration temperature of GPF, the heat resistant temperature, etc. have different characteristics, such as the activation temperature and heat resistant temperature of the catalyst.

  For example, if (the temperature of) the three-way catalyst is in an active state, but the PM deposition amount of GPF is equal to or greater than a predetermined value, and it is determined that regeneration control of GPF is necessary, regeneration control of GPF has priority The engine should be prohibited from coasting.

  On the other hand, when the PM deposition amount of GPF is less than a predetermined value and regeneration control of GPF is unnecessary, PM is captured by GPF without managing the temperature of GPF, so only the active state of the three-way catalyst The engine stop coasting should be judged (implemented).

  Thus, for example, in an exhaust system constituted by a combination of a three-way catalyst and a purification device having different characteristics such as GPF, priority is given to which of component protection, exhaust gas purification and fuel efficiency improvement depending on the state of each purification device. After determining whether it should be carried out, optimal engine control (freewheeling mode control) should be implemented.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to improve fuel efficiency by inertial running of a vehicle and to protect parts by optimal exhaust catalyst management of a plurality of purification devices disposed in an exhaust system. And providing a vehicle control device capable of achieving both

  In order to achieve the above object, a vehicle control device according to the present invention is an engine, and a purification device for purifying exhaust gas discharged from the engine, the exhaust system comprising a plurality of purification devices having different characteristics. An acceleration request detection unit for detecting a driver's acceleration request, and a deceleration request detection unit for detecting a driver's deceleration request, wherein the driver's acceleration request and deceleration request are under predetermined conditions; It is a vehicle control device for controlling a vehicle having a function of performing engine idle inertia running with the number of revolutions of the engine in an idle state, or engine stopping inertia running with the engine stopped and running, the vehicle control In the device, the state of all the purification devices in the exhaust system is engine stop inertia running execution predetermined for each purification device according to the characteristics of each purification device When meeting the matter is characterized by permitting the engine stop coasting.

  According to the present invention, the engine is stopped when the states of all the purification devices in the exhaust system satisfy the engine stop inertia running implementation conditions predetermined for each purification device according to the characteristics of each purification device. By permitting engine stop inertia running, it is possible to achieve both improvement in fuel efficiency by inertia running of the vehicle and protection of parts by optimal exhaust catalyst management of a plurality of purification devices provided in the exhaust system. .

  Problems, configurations, and effects other than those described above will be apparent from the description of the embodiments below.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the vehicle to which Embodiment 1 of the vehicle control apparatus (engine control system) which concerns on this invention is applied. It is a flowchart of freewheeling traveling control by Embodiment 1 of a vehicle control device (engine control system) concerning the present invention. It is the timing chart which showed the vehicle state in inertial travel change control by Embodiment 1 of the vehicle control device (engine control system) concerning the present invention by a time series. It is a flowchart of freewheeling traveling control by Embodiment 2 of a vehicle control device (engine control system) concerning the present invention. It is the timing chart which showed the vehicle state in inertial travel change control by Embodiment 2 of the vehicle control device (engine control system) concerning the present invention in a time series. It is a figure which shows the implementation area | region of the coasting mode with respect to the state of each catalyst in the vehicle to which Embodiment 2 of the vehicle control apparatus (engine control system) which concerns on this invention is applied.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1
<< Vehicle configuration >>
FIG. 1 is a schematic configuration view of a vehicle such as an automobile equipped with a gasoline engine (hereinafter simply referred to as an engine) to which a vehicle control device (engine control system) according to the present invention is applied.

  Vehicle 1 in FIG. 1 includes an engine 100, an exhaust system 200 for purifying exhaust gas discharged from the engine 100 and releasing the exhaust gas into the atmosphere, and a drive shaft 304 (a wheel serving as a driving device). And a transmission 300 having a transmission 302. Each component included in the engine 100 is controlled by the engine control system 101, and the clutch mechanism 301 of the transmission 300 and the transmission 302 are transmissions. It is controlled by the control system 303.

  Further, the vehicle 1 is provided with an accelerator pedal 404 and a brake pedal 405, and the driver's pedal (accelerator pedal 404 and brake pedal 405) operation is detected by an accelerator pedal sensor 401 and a brake pedal sensor 402. The engine control system 101 is input as an acceleration request and a deceleration request of the In other words, accelerator pedal sensor 401 and brake pedal sensor 402 function as an acceleration request detection unit and a deceleration request detection unit that detect the driver's acceleration request and deceleration request. The operation for the driver's request for acceleration or deceleration may be replaced by cruise control activated by the auto cruise switch 403.

<Engine 100>
The engine control system 101 is connected to a battery 501 as a power source, calculates a target torque from the driver's acceleration request, calculates the amount of air to be flowed into the engine 100, the amount of fuel injection, ignition timing, etc. Activate. At this time, the air amount, fuel injection amount, ignition timing and the like are corrected by air-fuel ratio feedback so that the exhaust system 200 can efficiently purify the exhaust gas.

  The amount of air flowing into the engine 100 is monitored by the air flow sensor 110 and adjusted by the degree of opening of the electronically controlled throttle 111. The degree of opening of the electronically controlled throttle 111 is determined by the engine control system 101 as the optimum degree of opening from the driver's request for acceleration or deceleration or the state of the vehicle 1.

  Air flowing into the engine 100 is drawn into a cylinder by opening the intake valve 112.

  While the engine 100 is rotating, piston movement by the piston 115 is transmitted to the connecting rod 116 and converted to circular movement by the crankshaft 117. During rotation of the engine 100, when a specific cylinder is in the suction process or compression process, the fuel injection device (injector) 113 injects fuel into the cylinder (here, direct injection), and mixes the mixture into the cylinder. Is formed.

  When the air-fuel mixture in the cylinder is compressed in the compression step and the piston 115 reaches near the top dead center, the spark plug 114 is spark-discharged, and the mixture is ignited to shift to the expansion step. As with the opening degree of the electronically controlled throttle 111, the fuel injection amount of the fuel injection device 113 and the fuel injection timing, and the ignition timing of the spark plug 114 are the engine control system 101 according to the driver's acceleration request, deceleration request, and the state of the vehicle 1. Is properly controlled.

  When the air-fuel mixture explodes and the expansion stroke ends, the exhaust valve 118 opens and the exhaust gas after combustion is sent to the exhaust system 200.

<Exhaust system 200>
The exhaust system 200 includes a three-way catalyst 212 and a gasoline particulate filter (GPF) 214, which are purification devices for purifying the exhaust gas discharged from the engine 100. The three-way catalyst 212 is a catalyst that purifies exhaust gas emitted from the engine 100 by a chemical reaction, and the GPF 214 is a catalyst that adsorbs and purifies PM contained in the exhaust gas emitted from the engine 100.

  The O 2 sensor 211 detects oxygen contained in exhaust gas emitted from the engine 100. The O2 sensor 211 is connected to the engine control system 101, and the engine control system 101 performs air-fuel ratio correction of the air amount and the fuel injection amount in the next combustion stroke from the residual oxygen concentration of the exhaust gas.

  The carbon monoxide or nitrogen oxides contained in a large amount in the exhaust gas just discharged from the engine 100 are reduced to water, carbon dioxide and nitrogen by the three-way catalyst 212 disposed downstream of the O 2 sensor 211. The temperature of the three-way catalyst 212 is monitored by a three-way catalyst temperature sensor 213, and the engine control system 101 adjusts the output of the engine 100 so that the temperature of the three-way catalyst 212 falls within a predetermined temperature range. Always do (more on this later). Here, the temperature of the three-way catalyst 212 is directly acquired by the three-way catalyst temperature sensor 213 attached to the three-way catalyst 212, but may be acquired indirectly.

  The exhaust gas that has passed through the three-way catalyst 212 then passes through the GPF 214. The GPF 214 further removes PM and harmful substances that can not be removed by the three-way catalyst 212. The temperature of the GPF 214 is monitored by a GPF temperature sensor 215, and the engine control system 101 constantly adjusts the output of the engine 100 so that the temperature of the GPF 214 falls within a predetermined temperature range (described in detail later). . Here, the temperature of the GPF 214 is directly obtained by the GPF temperature sensor 215 attached to the GPF 214, but may be obtained indirectly.

  In addition, a GPF upstream pressure sensor 216 and a GPF downstream pressure sensor 217 are attached to the upstream and downstream of the GPF 214, respectively. When the amount of PM deposition in the GPF 214 is small, the difference between the pressure indicated by the GPF upstream pressure sensor 216 and the pressure indicated by the GPF downstream pressure sensor 217 is small. On the other hand, when the PM deposition amount of the GPF 214 is large, the difference between the pressure indicated by the GPF upstream pressure sensor 216 and the pressure indicated by the GPF downstream pressure sensor 217 becomes large. The pressure difference between the pressure sensors (the GPF upstream pressure sensor 216 and the GPF downstream pressure sensor 217) enables monitoring of the PM deposition amount of the GPF 214.

  The exhaust gas that has passed through the GPF 214 is further discharged to the atmosphere through a downstream silencer (not shown).

<Transmission 300>
On the other hand, the transmission 300 includes a clutch mechanism 301 for transmitting or disconnecting the power of the engine 100 to the wheels (via the drive shaft 304), and a transmission 302 for outputting a predetermined torque from the rotation of the engine 100 to the wheels. And

  The output of engine 100 is transmitted by clutch mechanism 301. The clutch release or engagement of the clutch mechanism 301 is automatically performed by the transmission control system 303 in accordance with the driver's acceleration request or deceleration request, the state of the vehicle 1 or the like. The engine control system 101 and the transmission control system 303 described above communicate with each other to carry out cooperative control.

  Here, the engine control system 101 permits inertia running when there is no driver's acceleration request and deceleration request (that is, when the driver tries to drive the vehicle 1 at a constant speed). There is.

  Upon receiving the freewheeling permission signal from engine control system 101, transmission control system 303 causes clutch mechanism 301 to release the clutch to shut off transmission of power of engine 100, or transmission 302 is shifted to a neutral gear. And outputs a command for interrupting the power transmission to the drive shaft 304 to each component.

<< Flow of free-running switching control >>
FIG. 2 shows the state of each purification device (three-way catalyst a 212, GPF 214) in the exhaust system 200 according to the first embodiment of the vehicle control device (engine control system) according to the present invention; , Engine stop inertia running) is a flow chart of control.

  The operations of steps s101 to s106 shown in this flowchart are periodically executed in the engine control system 101 of FIG.

<Judgment of transition to inertia run: s101>
In step s101 of FIG. 2, the engine control system 101 determines that cruise is possible with the output of the engine 100 at low load, and permits transition to coasting (satisfying coasting start operation condition).

  In this embodiment, in a state where (the clutch of) the clutch mechanism 301 of the transmission 300 is released (that is, transmission of power of the engine 100 is interrupted), engine idle inertia travels with the engine 100 (rotational speed thereof) in an idle state. Two modes (modes) of coasting are implemented: traveling and engine stop coasting, in which the engine 100 is stopped with the clutch mechanism 301 released.

  In the present embodiment, the engine stop or the engine idle state is set with the clutch mechanism 301 released, but the gear of the transmission 302 is made neutral with the clutch mechanism 301 engaged, and the engine stop or the idle state It may be

  Further, the criterion for determining that the output of the engine 100 is low load is a state in which the accelerator pedal 404 is constantly stepped within the predetermined range by the driver, and the vehicle is operating while maintaining a constant speed, or This is a case where the engine control system 101 controls the output of the engine 100 by the auto cruise function implemented by the driver operating the cruise control switch 403 in a state where the driver does not operate the pedal at speed. These criteria for judging whether the engine load is low are just an example, and in addition to the above, for example, a downward slope is detected by an acceleration sensor or an inclination sensor, and a situation where traveling can be performed while suppressing the engine speed while maintaining the vehicle speed It may be used as a standard.

<First catalyst (three-way catalyst) diagnosis: s102>
In step s102 of FIG. 2, diagnosis of the three-way catalyst 212, which is the first purification device (catalyst), is performed.

  For example, in this diagnosis, the temperature of the three-way catalyst 212 (monitored by the three-way catalyst temperature sensor 213) is measured, and it is determined whether the temperature of the three-way catalyst 212 is within a predetermined temperature range.

  If the temperature of the three-way catalyst 212 does not exceed the lower limit of the three-way catalyst activation temperature, activation is insufficient and purification of the exhaust gas is not efficiently performed.

  Also, if the temperature of the three-way catalyst 212 is high (above the engine stop inertia running upper limit), cooling by the exhaust gas flow can not be performed when the engine 100 is stopped, and the three-way catalyst 212 may be burnt out There is.

  Taking these into consideration, as the first condition for performing (permitting) engine stop inertia running, if the temperature of the three-way catalyst 212 is within the predetermined temperature range, the process proceeds to step s103 with no problem.

  On the other hand, when the temperature of the three-way catalyst 212 is out of the predetermined temperature range, the process proceeds to step s110, and only engine idle inertia running is permitted.

  In step s102, although the temperature of the three-way catalyst 212 is monitored by the three-way catalyst temperature sensor 213 and permission or prohibition of engine stop inertia running is set, for example, connection of the three-way catalyst temperature sensor 213 and the engine control system 101 is performed. If the condition is not good, it may be determined that the temperature of the three-way catalyst 212 can not be acquired accurately, and a condition to shift to step s110 may be added.

<Second catalyst (GPF) diagnosis: s103>
In step s103 of FIG. 2, diagnosis of the GPF 214 which is the second purification device (catalyst) is performed.

  For example, in this diagnosis, it is determined whether the temperature of the GPF 214 (monitored by the GPF temperature sensor 215) is within a predetermined temperature range.

  When the temperature of the GPF 214 is high (above the GPF abnormal temperature threshold), when the engine 100 is stopped, the cooling by the exhaust gas flow can not be performed, and the GPF 214 may be burnt out.

  In consideration of that, when the temperature of the GPF 214 is out of the predetermined temperature range, the process proceeds to step s110, and only engine idle inertia running is permitted.

  Also, here, the pressure difference between the GPF upstream pressure sensor 216 and the GPF downstream pressure sensor 217 is confirmed, and it is evaluated whether the difference between the front and rear pressure of the GPF 214 is within a predetermined range.

  In the case where the difference between the front and rear pressure of the GPF 214 is small, the presence of a crack in the GPF 214, a sensor failure or the like may be considered.

  In addition, when the difference between the front and rear pressure of the GPF 214 is large, the collected PM is over-deposited, and GPF regeneration control described later is necessary. In this case, the engine idle coasting is permitted, and the GPF regeneration control is executed to burn the collected PM by the heat of the exhaust gas.

  Therefore, as a second condition for performing (permitting) engine stop inertia running, when the temperature difference between GPF 214 and GPF 214 is within the predetermined range, there is no problem, and the process proceeds to step s104, and engine idle inertia Allow to run.

  On the other hand, when the above-mentioned second condition is not established, the process shifts to step s110, and only engine idle inertia running is permitted.

  In the present embodiment, since the three-way catalyst 212 generally has a temperature management condition that is stricter than that of the GPF 214, the diagnosis of the three-way catalyst 212 disposed upstream is performed and then the diagnosis of the GPF 214 disposed downstream is performed. Of course, the diagnosis of the three-way catalyst 212 may be performed after the diagnosis of the GPF 214 is performed.

<Engine stop permission condition judgment: s105>
At step s104 in FIG. 2, the engine idle inertia running mode is temporarily permitted, and at step s105 it is determined whether to permit or prohibit the engine stop inertia running mode (the engine stop permission condition is satisfied).

  This engine stop determination is determined by the state of the vehicle 1 other than the states of the three-way catalyst 212 and the GPF 214. For example, it may be considered that the condition that the engine stop inertia running is prohibited is added when the battery 501 (for example, the battery voltage thereof) mounted on the vehicle 1 is out of the condition for permitting the engine stop inertia running .

  If it is determined in step s105 that the engine stop inertia running execution (permission) condition is not established, step s106 is skipped, and engine idle inertia running is continuously executed.

  On the other hand, when it is determined in step s105 that the engine stop inertia running execution (permission) condition is established, the process proceeds to step s106, and the engine stop inertia travel is permitted.

<< Vehicle status in freewheeling switching control >>
In the timing chart of FIG. 3, the vehicle control apparatus (engine control system) according to the present invention continuously executes the control described based on the flowchart shown in FIG. 18 shows an example of changes in each parameter of the engine 100 and the vehicle 1 when the engine idle inertia running or the engine stop inertia running is performed while monitoring the state of a212 and GPF 214).

  At t0 in FIG. 3, the driver operates the accelerator pedal 404, and the vehicle 1 accelerates to t1. At t1, it is determined that the vehicle speed VSP intended by the driver has been reached, and pedal operation to maintain a constant speed is performed. When t2 is reached, the coasting start operation condition described in step s101 of FIG. 2 is satisfied.

  At t2, the catalyst temperature C ATT of the three-way catalyst 212 has not reached the lower limit of the three-way catalyst activation temperature, and the three-way catalyst 212 still does not function sufficiently. Therefore, the determination in step s102 of FIG. 2 is negative, and the process proceeds to step s110, where engine idle inertia running is performed.

  At this time, (the clutch of) the clutch mechanism 301 changes from the engaged state to the released state, and transmission of the driving force of the engine 100 to the transmission 302 stops (shuts off). At t3, the driver's request for acceleration and deceleration is eliminated, and from t4 to t5, the driver operates the brake pedal 405 to decelerate, and at t5, the vehicle 1 stops.

  When the driver operates the accelerator pedal 404 again at t6, the clutch of the clutch mechanism 301 is engaged and the vehicle 1 starts to accelerate.

  At t7, as at t1, it is determined that the vehicle speed VSP intended by the driver has been reached, and a pedal operation is performed to maintain a constant speed. When t8 is reached, the coasting start operation condition described in step s101 of FIG. 2 is satisfied.

  At t8, the catalyst temperature C ATT of the three-way catalyst 212 is within the three-way catalyst activation temperature lower limit and the engine stop inertia running prohibition upper limit range, and the three-way catalyst 212 is in a fully functional state. Therefore, the three-way catalyst temperature condition is established in step s102 of FIG. 2, and the process proceeds to step s103.

  Next, the GPF diagnosis described in step s103 of FIG. 2 is performed. Here, only the temperature condition of the GPF 214 is considered.

  The temperature (GPF temperature) GPFT of GPF 214 at t8 in FIG. 3 indicates a value lower than the GPF temperature abnormal threshold. Therefore, the process shifts to the process of step s104 in FIG. 2 and engine idle inertia running is performed.

  After such evaluation is performed at t8, the engine idle coasting is performed, and the engine speed N decreases toward the idle speed at t9.

  At t9 to t10, after executing the engine idle inertia running, it is determined whether or not the engine stop inertia running execution condition is satisfied. At t10, a predetermined engine stop inertia running execution condition is satisfied. Then, the engine speed N becomes 0 (engine stop).

  As described above, in the present embodiment, in the vehicle 1 having a configuration in which a plurality of purification devices (the three-way catalyst 212 and the GPF 214) exist in the exhaust system 200, a state where each purification device can shift to engine stop inertia running If the state of any purification device does not satisfy the engine stop inertia running condition, the engine stop inertia running is not permitted (prohibited), in other words, the state of all purification devices By permitting the engine stop inertia running only when the engine stop inertia running execution condition is satisfied, it is possible to improve the fuel efficiency by the inertia running of the vehicle 1 and to protect the parts of all the purification devices disposed in the exhaust system 200. Become.

Second Embodiment
<< Flow of free-running switching control >>
FIG. 4 shows the state of each purification device (three-way catalyst a 212, GPF 214) in the exhaust system 200 according to the second embodiment of the vehicle control device (engine control system) according to the present invention from coasting (engine idle coasting) , Engine stop inertia running) is a flow chart of control.

  The flowchart of FIG. 4 shows an embodiment in which the above-mentioned flowchart of FIG. 2 is improved and the reproduction control of the GPF 214 is considered.

  The configuration of the vehicle itself to which the vehicle control device (engine control system) of the second embodiment is applied is the same as the configuration described based on FIG. 1.

  Steps s201, s202 and s203 in FIG. 4 correspond to steps s101, s102 and s103 in FIG. 2, respectively, and in steps s201 and s202 in FIG. 4, steps s101, s102 and s102 in FIG. Similar processing is performed.

  The process flow from the second catalyst (GPF 214) diagnosis when the result of the first catalyst (three-way catalyst 212) diagnosis in step s202 of FIG. 4 is not abnormal and the process proceeds to step s203 will be described below.

<Second catalyst (GPF) diagnosis (PM deposition diagnosis): s203>
In the present embodiment, the diagnosis of the PM deposition amount of the second catalyst (GPF 214) is performed in the diagnosis of step s203 of FIG.

  The PM deposition amount of the GPF 214 can be calculated from the pressure difference between the two pressure sensors and the flow rate or mass of the exhaust gas, while confirming the pressure difference between the GPF upstream pressure sensor 216 and the GPF downstream pressure sensor 217 as described above.

  In step s203, the necessity or non-necessity of the regeneration control of the GPF 214 is determined from the PM deposition amount of the GPF 214. That is, when the PM deposition amount is acquired by the above-described method, and the PM deposition amount does not exceed (is less than) the GPF regeneration control start threshold (also referred to as filter regeneration control execution deposition amount), the process proceeds to step s204. Allows engine idle inertia running.

  On the other hand, if it is determined in step s203 that the PM deposition amount in the GPF 214 exceeds (is equal to) the GPF regeneration control start threshold, the process moves to step s211.

<GPF regeneration control condition judgment: s211>
In step s211, it is determined whether the GPF temperature acquired by the GPF temperature sensor 215 exceeds the GPF regeneration temperature.

  The present embodiment shows a method of directly measuring the temperature of the GPF 214 using the GPF temperature sensor 215. For example, the method of estimating the temperature of the GPF 214 from the temperature measured by the upstream three-way catalyst temperature sensor 213 is shown. You may get it.

  If the GPF temperature exceeds the GPF regeneration temperature, the process proceeds to step s212, the target engine speed of the engine 100 is set as the engine idle speed, and the process proceeds to step s213 to permit engine idle inertia running.

  In step s211, when the GPF temperature does not exceed the GPF regeneration temperature, the process proceeds to step s221. In step s221, in order to raise the temperature of GPF 214 to the reproducible temperature (GPF regeneration temperature), a rotational speed obtained by adding an offset to the engine idle speed is set as the target engine rotational speed of engine 100. Thereafter, in step s213 Shift to allow engine idle inertia running.

  In this embodiment, as the target engine rotational speed when the GPF temperature is equal to or lower than the GPF regeneration temperature, an idle rotational speed plus an offset is adopted, but in the case of performing regeneration control during engine idle inertia running in advance The target engine speed may be set in advance.

  In the present embodiment, the temperature of the GPF 214 is increased by increasing the idle speed of the engine 100. However, in the case of a gasoline engine, the air speed, the fuel injection amount, and the ignition are maintained while the engine speed remains stationary. Temperature correction is also possible by correcting the time. For example, by simultaneously increasing the intake air amount and retarding the ignition timing, it is possible to transfer the heat generated in the cylinders of the engine 100 to the exhaust system 200 while maintaining the same engine speed. In addition, by adjusting the fuel injection amount and setting the proportion of the fuel to be rich (rich), the chemical reaction of the three-way catalyst 212 is promoted and the temperature is raised, and high temperature gas is allowed to flow downstream thereof to It is also conceivable to increase the temperature. The engine control system 101 may perform such air amount correction, fuel injection amount correction, and ignition timing correction to apply the control for increasing the temperature of the GPF 214 to step s221.

<GPF playback control end judgment>
When it passes through step s212 or step s221 of FIG. 4, at step s213, engine idle inertia running is permitted (implemented).

  The second catalyst (GPF) diagnosis of step s203 is repeatedly performed by sequentially executing the flowchart of FIG. 4 at a predetermined timing. As the GPF temperature is maintained at the temperature necessary for GPF regeneration control (GPF regeneration temperature), PM trapped by the GPF 214 is reduced.

  When the PM deposition amount of the GPF 214 becomes less than the predetermined value (filter regeneration control execution deposition amount), the diagnosis result of step s203 becomes normal, and the process moves to step s204, and the GPF regeneration control is ended.

  In steps s204, s205, and s206 in FIG. 4, the same processing as in steps s104, s105, and s106 in FIG. Driving, engine stop and free running) are carried out.

<< Vehicle status in freewheeling switching control >>
In the timing chart of FIG. 5, the vehicle control apparatus (engine control system) according to the present invention continuously executes the control described based on the flowchart shown in FIG. As a result of monitoring the state of a212 and GPF 214, it shows an example of change of each parameter of engine 100 and vehicle 1 when engine idle inertia running or engine stop inertia running is performed while performing regeneration control of GPF 214. is there.

  At t11 in FIG. 5, the driver operates the accelerator pedal 404, and the vehicle 1 accelerates at t12. At t12, it is determined that the vehicle speed VSP intended by the driver has been reached, and a pedal operation to maintain a constant speed is performed. When t13 is reached, the coasting start operation condition described in step s201 of FIG. 4 is satisfied.

  At t13, the catalyst temperature CATT of the three-way catalyst 212, the temperature (GPF temperature) GPFT of the GPF 214, and the PM deposition amount GPFPM of the GPF 214 are determined to determine permission of engine idle inertia running.

  At t13, the catalyst temperature CATT of the three-way catalyst 212 is within the three-way catalyst activation temperature lower limit and the engine stop inertia running prohibition upper limit range, and the three-way catalyst 212 is in a fully functioning state. Therefore, the three-way catalyst temperature condition is established in step s202 of FIG. 4, and the process moves to step s203.

  Next, the PM deposition amount GPFPM of the GPF 214 at t13 is higher than the filter regeneration control execution deposition amount. Therefore, the process shifts to the process of step s211 of FIG. 4 to execute the evaluation of the GPF temperature GPFT.

  At t13, the GPF temperature GPFT has not reached the GPF regeneration temperature. Therefore, the process transitions to step s221, and the engine idle inertia running is performed at t14 with the engine speed N at the time of the inertia running as the idle speed + offset.

  From t14 to t15, since the GPF temperature does not reach the GPF regeneration temperature, the idle speed is increased (by the offset amount) to raise the temperature of the GPF 214.

  At t15, since the GPF temperature reaches the GPF regeneration temperature, the GPF regeneration is started, and the PM deposition amount GPFPM of the GPF 214 decreases.

  When the GPF temperature exceeds the GPF regeneration temperature at t15, the temperature condition is satisfied in the evaluation of step s211 in FIG. Therefore, the process shifts to step s212, and the idle speed during engine idle inertia running is set to the same speed as the normal idle speed.

  The section from t16 to t17 represents that the accelerator pedal 404 is depressed again by the driver's request for acceleration, the engine speed N increases, and the vehicle speed VSP increases. In this section, the high temperature exhaust gas is sent to the three-way catalyst 212 and the GPF 214 by the increase of the engine rotational speed N, the GPF temperature is maintained at the GPF regeneration temperature or more, the regeneration control is continued, and the PM deposition amount is GPFPM is further reduced.

  At t17, as at t12, it is determined that the vehicle speed VSP intended by the driver has been reached, and a pedal operation to maintain a constant speed is performed. When t18 is reached, the coasting start operation condition described in step s201 of FIG. 4 is satisfied.

  At t18, the three-way catalyst 212 is fully functioning, and the PM deposition amount of the GPF 214 is less than a predetermined value (filter regeneration control execution deposition amount). Therefore, the process shifts from step s203 to step s204 in FIG. 4 to carry out engine idle inertia running.

  After such evaluation is performed at t18, the engine idle coasting is performed, and the engine speed N decreases toward the idle speed at t19.

  During the engine idle inertia running from t19 to t20, step s205 of FIG. 4 is evaluated (judged whether or not the engine stop inertia running execution condition is satisfied), and the engine stop inertia running execution condition defined in advance is satisfied at t20. Then, the engine speed becomes 0 (engine stop).

  As described above, in the second embodiment, in addition to the temperature of the three-way catalyst 212 provided in the exhaust system 200, the temperature of the GPF 214 and the amount of PM deposition are monitored, and engine stop inertia running is permitted (implemented) It was prohibited, but by using PM deposition amount of GPF 214 as a condition, when PM deposition amount is low, engine stop inertia running is possible only with temperature condition of the three-way catalyst 212, and further improvement of fuel efficiency is expected Be

<< Implementation area of freewheeling mode for each catalyst state >>
FIG. 6 shows the practical ranges of engine idle inertia running and engine stop inertia running which are determined according to the states of the first catalyst (three-way catalyst 212) and the second catalyst (GPF 214) described above. The upper side of the horizontal axis is the temperature of the three-way catalyst 212 which is the condition of the first catalyst, the lower side of the horizontal axis is the temperature of GPF 214 which is the condition of the second catalyst, and the vertical axis is the condition of the second catalyst The PM deposition amount of GPF 214 is shown.

  In the region A of FIG. 6, the temperature of the three-way catalyst 212 is lower (than the lower limit of engine stop permission), and temperature rise is required. Therefore, engine stop inertia running is prohibited, and engine idle coasting is performed.

  Further, in the B region, the temperature of the three-way catalyst 212 is higher (above the engine stop permission upper limit) and cooling is required, so the engine stop inertia running is prohibited, and the engine idle inertia running is performed.

  That is, the region A and the region B are divided by the temperature of the three-way catalyst 212.

  In region C, the temperature of the three-way catalyst 212 satisfies the engine stop inertia running execution condition (that is, within the range of the engine stop permission lower limit and the engine stop permission upper limit), and the PM deposition amount of the GPF 214 controls regeneration. Since it is less than the start threshold value, the engine stop inertia running is carried out (according to the state of the vehicle 1 other than the states of the three-way catalyst 212 and the GPF 214).

  The C region is divided by the temperature of the three-way catalyst 212 and the PM deposition amount of the GPF 214.

  In the D and E areas, the temperature of the three-way catalyst 212 satisfies the engine stop inertia running execution conditions, but the PM deposition amount of the GPF 214 is high (with the regeneration control start threshold or more), and in the area where GPF regeneration control is required. is there. Here, in the D region, since the temperature of the GPF 214 exceeds the GPF reproducible temperature, normal engine idle inertia running is performed. On the other hand, in the E region, since the temperature of the GPF 214 is as low as the GPF regenerable temperature or lower, engine idle inertia running with catalyst heating of the GPF 214 is performed.

  That is, the D region and the E region are divided by the temperature of the three-way catalyst 212, the PM deposition amount of the GPF 214, and the GPF temperature.

[Operational effects of Embodiments 1 and 2]
As described above, according to the first and second embodiments, even when there are a plurality of purification devices having different characteristics in the exhaust system 200, the engine stop inertia running and the engine are performed according to the state of each purification device. Parts can be protected and fuel consumption can be improved by appropriately switching between idle coasting and traveling.

  Specifically, the vehicle 1 is contained in a first catalyst (three-way catalyst 212) for purifying exhaust gas emitted from the gasoline engine 100 by a chemical reaction, and in exhaust gas emitted from the gasoline engine 100. A second catalyst (GPF 214) for adsorbing PM is provided.

  The three-way catalyst 212 and the GPF 214 are independently attached to each other (the exhaust pipe of the exhaust system 200), and the state of the three-way catalyst 212 and the state of the GPF 214 are respectively independent temperature sensors (three-way catalyst temperature sensor 213, GPF temperature It is monitored by the sensor 215). A pressure sensor (GPF upstream pressure sensor 216, GPF downstream pressure sensor 217) is mounted upstream and downstream of the GPF 214, and detects the PM deposition amount of the GPF 214 by monitoring the pressure difference before and after the GPF 214.

  Further, the vehicle 1 calculates an air inflow amount, a fuel injection amount, an ignition timing and the like of the gasoline engine 100 from an acceleration request or a deceleration request from a driver, and transmits an instruction signal to each part And a transmission control system 303 for controlling transmission and shutoff of the power of the engine 100 to the wheels, and the engine control system 101 controls the vehicle at a constant speed of the driver when there is no acceleration request or deceleration request of the driver. When driving 1), the engine 100 and the transmission 302 are disconnected to execute the engine idle inertia running or the engine stop inertia running.

  The engine control system 101 uses the temperature of the three-way catalyst 212, the temperature of the GPF 214, and the PM deposition amount of the GPF 214 in the determination when shifting from normal running to engine idle idle running (engine idle coasting). .

  That is, in the engine control system 101, the temperature of the three-way catalyst 212 is within a predetermined temperature range (within the range predetermined according to the characteristics of the three-way catalyst 212), and the PM deposition amount of the GPF 214 is low (GPF 214). If the GPF regeneration control start threshold (the filter regeneration control execution accumulation amount) is smaller than a predetermined threshold value according to the characteristics of (1), the engine stop inertia running is permitted.

  In addition, when the temperature of the three-way catalyst 212 is within a predetermined temperature range and the PM deposition amount of the GPF 214 is high (GPF regeneration control start threshold (filter regeneration control execution deposition amount) or more), engine idle inertia running Allow, do not allow (stop) the engine stop coasting.

  In addition, when the above-mentioned engine idle inertia running (when PM deposition amount of GPF 214 is high), GPF temperature is low (equal to or less than the GPF regeneration temperature predetermined according to the characteristics of GPF 214), the predetermined temperature The temperature of the GPF 214 is raised to be higher than (GPF regeneration temperature).

  Thus, by independently monitoring the temperature of the three-way catalyst 212, which is the first purification device (catalyst), and the temperature of the GPF 214, which is the second purification device (catalyst), the fuel consumption due to the inertia running of the vehicle 1 It is possible to simultaneously perform the improvement and component protection of the three-way catalyst 212 and the GPF 214 disposed in the exhaust system 200.

  In addition, by monitoring the pressure of the exhaust system 200 in addition to the temperature of the three-way catalyst 212 and the temperature of the GPF 214 under the condition that permits execution of the engine stop inertia running, the engine stop without satisfying all the temperature conditions for each purification device. It becomes possible to shift to coasting, and it is possible to further improve the fuel consumption.

[Modified form]
The present invention is not limited to the above-described embodiment, but includes various modifications. For example, the above-described embodiment is described in detail to explain the present invention in an easy-to-understand manner, and is not necessarily limited to one having all the described configurations. Further, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, and replace other configurations for part of the configurations of the respective embodiments.

  For example, in the above embodiment, a system configured by a combination of a three-way catalyst and a GPF has been described, but the present invention is not limited to this combination, a combination of a three-way catalyst and a three-way catalyst, or a V-type engine Application to the left and right independent exhaust systems that can be seen is also possible.

  Moreover, in the said embodiment, although GPF for gasoline engines was used for description, this invention is applicable not only to a gasoline engine but to a diesel engine.

  Moreover, although the case where it applied to the direct injection system of a gasoline engine was demonstrated in the said embodiment, this invention is applicable also to the engine of a port injection system.

100: Engine, 101: Engine control system (vehicle control device), 110: Air flow sensor, 111: Electronic control throttle, 112: Intake valve, 113: Fuel injection device (injector , 114: spark plug, 115: piston, 116: connecting rod, 117: crankshaft, 118: exhaust valve, 200: exhaust system, 211: O2 sensor, 212 ... Three-way catalyst (purifying device), 213 ... Three-way catalyst temperature sensor, 214 ... GPF (gasoline particulate filter) (purifying device), 215 ... GPF temperature sensor, 216 ... GPF Upstream pressure sensor 217 GPF downstream pressure sensor 301 clutch mechanism 302 transmission 303 to 303 Nsu mission control system, 401 ... accelerator pedal sensor, 402 ... brake pedal sensor, 403 ... cruise control switch, 404 ... accelerator pedal, 405 ... brake pedal, 501 ... Battery

Claims (7)

With the engine,
An exhaust system comprising a plurality of purification devices for purifying exhaust gas discharged from the engine, the purification device comprising a plurality of purification devices having different characteristics;
An acceleration request detection unit that detects the driver's acceleration request;
A deceleration request detection unit that detects a driver's deceleration request;
Engine idle coasting traveling with the engine speed set to idle when the driver's acceleration request and deceleration request are under predetermined conditions, or engine stop coasting traveling with the engine stopped. A vehicle control apparatus for controlling a vehicle having a function to be implemented, comprising:
The vehicle control device is configured to stop the engine when the state of all the purification devices in the exhaust system satisfies an engine stop inertia running execution condition predetermined for each purification device according to the characteristics of each purification device. travel permits,
The plurality of purification devices include at least a three-way catalyst and a GPF,
The vehicle control device
When the temperature of the three-way catalyst is out of a predetermined temperature range, the temperature of the GPF is out of a predetermined temperature range, or the PM deposition amount of the GPF is a predetermined threshold or more, only the engine idle inertia running is permitted. , Do not allow the engine stop coasting,
The engine idle inertia running is permitted when the temperature of the three-way catalyst is within a predetermined temperature range, the temperature of the GPF is within a predetermined temperature range, and the PM deposition amount of the GPF is less than a predetermined threshold. The engine stop inertia running condition is determined based on the three-way catalyst and the state of the vehicle other than the state of the GPF while the engine idle inertia running is permitted, and the engine stop inertia running is determined. When it is determined that the implementation condition is not established, the engine idle inertia running is continuously executed, and when it is determined that the engine stop inertia running implementation condition is established, the engine stop inertia traveling is permitted . A vehicle control device characterized by With the engine,
An exhaust system comprising a plurality of purification devices for purifying exhaust gas discharged from the engine, the purification device comprising a plurality of purification devices having different characteristics;
An acceleration request detection unit that detects the driver's acceleration request;
A deceleration request detection unit that detects a driver's deceleration request;
Engine idle coasting traveling with the engine speed set to idle when the driver's acceleration request and deceleration request are under predetermined conditions, or engine stop coasting traveling with the engine stopped. A vehicle control apparatus for controlling a vehicle having a function to be implemented, comprising:
The vehicle control device controls the engine idle inertia when the state of all the purification devices in the exhaust system satisfies an engine stop inertia running execution condition predetermined for each purification device according to the characteristics of each purification device. In a state in which traveling is permitted and the engine idle inertia traveling is permitted, it is determined whether or not the engine stop inertia traveling execution condition determined by the state of the vehicle other than the states of all purification devices in the exhaust system. If it is determined that the engine stop inertia running condition is not satisfied, the engine idle inertia running is continued and it is determined that the engine stop inertia running condition is satisfied. A vehicle control device characterized by permitting stop coasting. When the temperature or pressure acquired directly or indirectly in each purification device of the exhaust system satisfies the temperature condition or pressure predetermined for each purification device, the vehicle control device runs the engine stop coasting The vehicle control apparatus according to claim 2 , wherein: The plurality of purification devices include at least a three-way catalyst and a GPF,
The vehicle control device is characterized in that the engine stop inertia running is permitted when the temperature of the three-way catalyst is within a predetermined temperature range and the amount of PM deposition of the GPF is less than a predetermined threshold. The vehicle control device according to claim 2 . The plurality of purification devices include at least a three-way catalyst and a GPF,
The vehicle control device permits the engine idle inertia running when the temperature of the three-way catalyst is within a predetermined temperature range and the PM deposition amount of the GPF is equal to or more than a predetermined threshold, and the engine stop inertia The vehicle control device according to claim 2 , wherein the vehicle control unit does not permit traveling. The vehicle control device is configured to allow the temperature of the GPF to be higher than the predetermined temperature threshold when the temperature of the GPF is equal to or lower than the predetermined temperature threshold while permitting the engine idle inertia running. and performing heating of GPF, the vehicle control device according to claim 1 or 5. The vehicle control device executes diagnosis of the GPF disposed downstream of the exhaust system after performing diagnosis of the three-way catalyst disposed upstream of the exhaust system. The vehicle control device according to 1 or 5.

Images