JP2008202470A - Control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently and effectively inhibit emission of NOx. <P>SOLUTION: ECU 100 executes NOx reduction process on a vehicle 10. In the process, ignition timing retarding control is executed to always retard ignition timing from reference ignition timing by fixed retarding angle when it is determined that it is a situation where NOx emission need to be inhibited such as (i) atmospheric environment around the vehicle is easily contaminated by atmospheric pollutant, (ii) NOx inhibition objective person whose resistance against NOx is poor such as a child, an aged person and a sick person exists around the vehicle 10, (iii) concentration of atmospheric pollutant is high around the vehicle 10, based on information or the like relating to a position of own vehicle and facilities and environment around the vehicle 10 provided by a car navigation system 300, an NOx sensor 400, an external air temperature sensor 500, an ozone sensor 600 and an on-vehicle clock 700 or the like. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technical field of a control device for an internal combustion engine for suppressing, for example, NOx (nitrogen oxide) emission.

  As this type of apparatus, an apparatus that stops an internal combustion engine has been proposed (see, for example, Patent Document 1). According to the hybrid electric vehicle disclosed in Patent Document 1 (hereinafter referred to as “conventional technology”), when it is determined that the current position of the vehicle is within the air pollution prevention enhanced area in the hybrid vehicle, It is said that air pollution is surely prevented by stopping the engine and running the motor. Further, since the lower limit capacity value of the remaining capacity of the battery is set to a value that is larger than the minimum capacity that can drive the vehicle by a required capacity, it is assumed that the running capacity is secured while preventing air pollution. ing.

Japanese Patent No. 3092403

  The prior art is effective only in a hybrid vehicle having a power source in addition to the internal combustion engine, and in a vehicle having only the internal combustion engine as a power source, the stop of the internal combustion engine, that is, the vehicle is stopped. It is. Of course, depending on the state of charge of the battery, it may be impossible to run the motor, and there may be a situation where the internal combustion engine cannot be stopped even in an area where air pollution prevention is enhanced. In addition, there are many situations where air pollution should be prevented even in areas other than those designated as areas where air pollution prevention is strengthened. As a viewpoint other than such air pollution prevention, for example, the elderly In addition, the presence or absence of actual air pollution or the presence of air pollutants is not preferable for the sick or the like. Accordingly, in the prior art, the emission of air pollutants is only suppressed in a limited part of the case where the emission of air pollutants should be suppressed in a limited manner. . That is, the conventional technique has a technical problem that the air pollutant is not sufficiently discharged and cannot have a substantially remarkable effect.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a control device for an internal combustion engine that can efficiently and effectively suppress the discharge of air pollutants, particularly NOx.

  In order to solve the above-described problems, an internal combustion engine control device according to the present invention is a control device for an internal combustion engine that controls the internal combustion engine in a vehicle equipped with the internal combustion engine, and determines whether or not NOx is discharged in the vehicle. Specifying means for specifying a predetermined type of associated driving condition; determining means for determining whether or not to suppress the NOx emission based on the specified driving condition; and suppressing the NOx emission And control means for controlling the internal combustion engine so that the NOx emission amount is at least relatively reduced when the determination is made.

  An “internal combustion engine” according to the present invention has a plurality of cylinders, for example, and includes a fuel such as gasoline that is directly injected into an intake system such as an intake pipe or an intake port or directly into a combustion chamber in the cylinder. It is a concept that encompasses an engine that is configured to combust air and to take out the explosive force associated with the combustion as power through, for example, a piston, a connecting rod, a crankshaft, and the like. Cycle reciprocating engine.

  According to the control apparatus for an internal combustion engine according to the present invention, at the time of its operation, for example, specifying means configured as various processing units such as an ECU (Electronic Control Unit), various controllers or various computer systems such as a microcomputer device, etc. Depending on, for example, the current position of the vehicle (hereinafter referred to as “own vehicle position” as appropriate) and the surroundings of the vehicle (may include the own vehicle position or the vicinity of the travel route of the own vehicle, The presence of a person with low resistance to air pollutants, such as the elderly or a sick person, Various conditions related to environmental conditions such as presence conditions, outside air temperature, wind direction, air volume, air pressure or humidity, current time or time zone, or air pollution, including scale, etc. Issued status of broadcast or warning (e.g., positional relationship between the issued area and the vehicle position) as wide concept including such as driving conditions associated with the discharge propriety of NOx in the vehicle is specified.

  Note that “specific” in the present invention corresponds to, for example, detection directly or indirectly as information, data, or signal via some detection means, or a map stored in an appropriate storage means or the like in advance. Selecting a numerical value to be estimated or estimating through such selection, information, data or signal detected, or a numerical value selected or estimated based on a preset algorithm, calculation formula or logical formula It is a broad concept encompassing deriving or estimating according to the above, or acquiring the value detected, selected, estimated or derived as information, data, signals, or the like.

  On the other hand, when the vehicle driving conditions are specified in this way, for example, based on the specified driving conditions by condition determining means configured as various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device. Thus, it is determined whether or not NOx emission should be suppressed (that is, whether or not the amount of NOx in the exhaust gas should be reduced).

  Here, since NOx does not already have any benefit in its generation, “whether NOx emissions should be suppressed” can be strictly speaking all operating engines of the internal combustion engine. However, in view of such a purpose, the control device for an internal combustion engine according to the present invention particularly ensures the vehicle performance (remarkably power performance) as much as possible or at least in view of the vehicle running conditions described above. However, NOx emissions can be suppressed in preference to operating the internal combustion engine under reference operating conditions (for example, operating conditions corresponding to a situation where no possibility of NOx emission is considered). It is a concept that represents whether or not it is objectively and reasonably determined to be operated under operating conditions. Within the scope of such a concept, “whether NOx emission should be suppressed” means, for example, that the specified driving condition is, for example, that the air is significantly polluted at the vehicle position or around the vehicle, There is a person who has low resistance to air pollutants in the surrounding area, or the environmental conditions that NOx emitted from the vehicle significantly affects the air pollution are met, or such conditions are expressed. It can take the form of whether or not.

  According to the control device for an internal combustion engine according to the present invention, when it is determined in this way that NOx emission should be suppressed, for example, various processing units such as an ECU, various controllers, or a microcomputer device The internal combustion engine is controlled by the control means configured as various computer systems or the like so that the NOx emission amount is at least relatively reduced.

  Here, “so that the amount of NOx emissions decreases at least relatively” means that it is sufficient that NOx is considerably reduced as compared with the case where at least this kind of control relating to NOx suppression is not performed. In view of the fact that the operating conditions of the internal combustion engine can constantly change when the vehicle is running, it is not necessarily necessary to be accompanied by a decrease in the absolute emission amount of NOx. However, as an operation concept of the control means, the internal combustion engine may be controlled so that the absolute emission amount of NOx decreases. That is, priority may be given to those who are less resistant to air pollution and air pollutants, and the running performance may be significantly reduced within a range in which the vehicle is not stopped.

  At this time, the control mode of the internal combustion engine performed to reduce the NOx emission amount is not limited as long as the NOx can be reduced at least relatively as described above. For example, NOx suppression such as retarding control of the ignition timing is performed. Various controls that are known to have the above effect may be employed, and as a simpler aspect, the fuel injection amount may be relatively reduced.

  As described above, according to the control apparatus for an internal combustion engine according to the present invention, it is possible to flexibly suppress the emission of air pollutants by reducing the NOx emission amount without stopping the traveling of the vehicle. . In this case, for example, not only in extremely limited situations such as the presence of vehicles in areas where air pollution prevention is strengthened, but also in a number of situations in which the suppression of the emission of air pollutants is remarkably and urgently desired, that is, in practice. It is possible to reduce the NOx emission amount with a high frequency enough to obtain a sufficient effect, and it is possible to efficiently and effectively suppress the NOx emission.

  In one aspect of the control apparatus for an internal combustion engine according to the present invention, the specifying means specifies at least a traffic state, a current time, and an air temperature within a predetermined range including the vehicle as the travel condition, and the determining means Determines that the NOx emission should be suppressed when the specified traffic condition, current time, and temperature satisfy the first condition that is preliminarily determined to facilitate air pollution. .

  According to this aspect, the specifying means is, for example, a traffic volume, an average speed, a traffic jam, etc. in a predetermined range including the vehicle (for example, a range such as a vehicle having a surrounding radius of OO km) as at least a part of the traveling condition. At least the traffic state, current time, and temperature as a concept appropriately including the presence or absence of traffic concentration or the scale of the traffic concentration are specified. The determination means determines that NOx emission should be suppressed when the specified traffic state, current time, and temperature satisfy the first condition.

  Here, the “first condition” is, for example, a condition in which the ground surface portion is at a lower temperature than the upper layer portion, an atmospheric inversion layer can be considered to be generated or predicted to occur, or NOx and HC ( It is considered that photochemical smog is generated as a phenomenon in which photochemical oxidants such as ozone and aldehyde are generated by causing a photochemical reaction with hydrocarbons), and progresses air pollution, including conditions that are expected to occur. It is a concept encompassing conditions that are easy to cause (including conditions that are likely to cause an increase in the concentration of an air pollutant that is defined as being capable of polluting the air environment or adversely affecting the human body).

  Such a criterion for determining whether or not the first condition is satisfied is, for example, in advance experimentally, empirically, theoretically or based on simulation or the like, and at least a practical defect (for example, the first Judgment is often made that the condition is satisfied despite not satisfying the first condition, or conversely, the determination that the condition is not satisfied is satisfied even though the first condition is satisfied. It is set as an appropriate algorithm, mathematical expression, numerical value, or the like, for example, that can be accurately discriminated to such an extent that the latter is more serious from the viewpoint of emphasizing the atmospheric environment and the latter is more serious. Also good. At this time, as an aspect in which simpler discrimination can be realized while maintaining accuracy, each element defining the first condition may be compared with a reference value, a reference state, or the like set as described above.

  For example, the physical, mechanical, mechanical, or electrical configuration of the specifying means is not limited at all, and the specifying means is different hardware provided according to each element included in the first traveling condition. It may be a collection of means having a wear configuration. Alternatively, in view of the concept of “identification” described above, the identification means can detect a traffic state defined by the concept described above, for example, a positioning system using a car navigation device, GPS (Global Positioning System), or the like, or VICS compatible car navigation system configured to detect VICS (Vehicle Information and Communication System) information emitted from various types of beacons such as radio wave beacons and optical beacons, an in-vehicle clock capable of detecting the current time, and outside temperature It may be a computer system such as various controllers or ECUs that can acquire each information or data corresponding to the information as, for example, an electric signal from various detection means such as a detectable outside air temperature sensor.

  According to this aspect, since NOx emission is suppressed in a situation where air pollution is likely to proceed, it is effective.

  In another aspect of the control apparatus for an internal combustion engine according to the present invention, the specifying means specifies at least a presence state of a NOx suppression target person within a predetermined range including the vehicle as the traveling condition, and the determining means includes Determining that the emission of NOx should be suppressed when the specified presence condition satisfies a second condition that the NOx suppression target person exists in advance within the predetermined range. Do.

  According to this aspect, the specifying unit specifies at least the presence state of the NOx suppression target person in a predetermined range including the vehicle (for example, a range such as a vehicle having a surrounding radius of OO km) as at least a part of the traveling condition. To do. Here, the “NOx suppression target person” is a person who has relatively low physical or mental resistance to air pollutants containing NOx, in other words, suppresses NOx emission compared to an adult healthy person. It is a concept that encompasses those who can enjoy more of the benefits of doing, for example, including various infants, children, mentally ill people, physically disabled people, inpatients and home patients, etc. is there. In addition, the “presence state” of the NOx suppression target person includes a quantitative stepwise or continuous and quantitative state such as a binary state indicating whether or not it exists, a scale of the presence, etc. It is a concept.

  On the other hand, the determination means determines that NOx emission should be suppressed when the specified presence condition satisfies the second condition. Here, the “second condition” is a concept encompassing conditions defined as the existence of a NOx suppression target person within the range, and the actual NOx suppression target person within such a range is actually accurate. In view of the fact that it is difficult to grasp the number of NOx, as a preferred embodiment, the resistance to NOx is remarkably large regardless of whether or not the NOx emission should be suppressed in practice. The purpose is to suitably include conditions that can be considered that a low NOx suppression target person exists. That is, the determination unit may perform the determination in at least a part of the case where it is determined that the NOx suppression target person exists within the range.

  For example, the physical, mechanical, mechanistic, or electrical configuration of the specifying means for specifying the presence state of the NOx suppression target person is not limited at all, and the specifying means is acquired through, for example, a car navigation device or the like. Various schools such as kindergartens, nursery schools, nursing schools and elementary and junior high schools, facilities for the physically handicapped, facilities for the mentally ill, hospitals, clinics, hospice and other medical facilities, and care, within a predetermined range including the position of the vehicle The presence state may be specified as information or data such as presence / absence and scale of various facilities that can be associated with the presence of the NOx suppression target person, such as a facility for elderly people such as a plaza and a nursing home. At this time, a determination that the second condition is satisfied may be made based on the fact that such a facility exists.

  According to this aspect, since the adverse effect of NOx on the NOx suppression target person can be relatively reduced, it is useful in practice.

  In another aspect of the control apparatus for an internal combustion engine according to the present invention, the specifying means includes, as the traveling condition, a concentration of air pollutants within a predetermined range including the vehicle, and an announcement state of notification information regarding air pollution. At least one of them is specified, and the determination means should suppress the emission of NOx when the specified at least one satisfies a third condition defined in advance as a high degree of air pollution. To determine.

  According to this aspect, the specifying unit is configured to detect air pollutants such as NOx and ozone in a predetermined range including the vehicle (for example, a range such as a vehicle radius XX km) as at least a part of the traveling condition. At least one of notification states of notification information as a concept including warnings and warnings on air pollution including concentration and photochemical smog is specified as a preferred form. Note that the “announced state” may take a binary state as to whether or not it has been issued as a preferred embodiment. The determining means determines that NOx emission should be suppressed when at least one of the specified conditions satisfies the third condition.

  Here, the “third condition” is a concept encompassing conditions preliminarily defined as those having a high degree of air pollution, and the discrimination means has, for example, a concentration of these air pollutants as a preferred embodiment. For example, when it is considered that the standard value set as the environmental standard is exceeded or exceeded, it is certain that warnings or warnings regarding photochemical smog or various air pollution are issued or issued. In such a case, it may be determined that the third condition is satisfied.

  For example, the physical, mechanical, mechanical or electrical configuration of the specifying means is not limited, and the specifying means can measure NOx concentration and ozone concentration from various detecting means such as a vehicle-mounted NOx sensor and ozone sensor. The result may be acquired as data, or the measurement result of NOx concentration or ozone concentration around the own vehicle may be acquired as a signal or data from infrastructure equipment such as an atmospheric measurement station. For example, a car navigation device, As a part of the VICS information described above, information regarding a warning or a warning issuing area may be acquired. Of course, you may have these several aspects together.

  According to this aspect, it is possible to prevent the pollution of the air from being promoted by the emission of NOx when the air is heavily polluted relatively, which is useful in practice.

  In another aspect of the control device for an internal combustion engine according to the present invention, the internal combustion engine includes an ignition device for igniting an air-fuel mixture, and the control means should suppress the emission of NOx. When the determination is made, the ignition device is controlled so that the ignition timing related to the ignition is retarded with respect to the reference ignition timing.

  According to this aspect, the internal combustion engine is provided with an ignition device such as a spark ignition device for igniting the air-fuel mixture, and the control means retards the ignition timing related to the ignition with respect to the reference ignition timing. It is possible to effectively reduce NOx emissions.

  The “reference ignition timing” described here is associated with, for example, the engine speed and the load (which may alternatively be represented by a load factor, an accelerator opening, a throttle opening, or the like). For example, it includes an ignition timing that is stored in advance as a map or the like, and further has a viewpoint different from the NOx emission reduction with respect to such an ignition timing, for example, a delay for suppressing or converging the occurrence of knocking. This is intended to include the ignition timing in a state where the angle control is performed. At this time, the retard amount of the ignition timing is not particularly limited in view of the fact that the combustion temperature inside the cylinder can be lowered by retarding the ignition timing and the amount of NOx produced can be suppressed. For example, the retard amount of the ignition timing is determined in advance experimentally, empirically, theoretically or based on simulations, for example, the ease of increasing the concentration of the air pollutant mentioned above, the distance to the weak, or the air pollution. It is determined so that the energy loss due to the retard of the ignition timing can be suppressed as much as possible while satisfying the NOx emission amount to be suppressed at that time, in a form corresponding to the degree of ignition, etc., or as a completely fixed value, for example. It may be done.

  In another aspect of the control device for an internal combustion engine according to the present invention, the internal combustion engine changes the opening / closing timing of at least one of the intake valve and the exhaust valve so that the output of the internal combustion engine is improved at least under a high load. The control means prohibits the operation of the variable valve device at the time of high load when it is determined that the NOx emission should be suppressed. To do.

  According to this aspect, the internal combustion engine is provided with, for example, VVT (Variable Valve Timing) or various variable valve gears similar thereto, and opens and closes at least one of the intake and exhaust valves so that the output is improved at least under a high load. It is possible to make the time variable. The physical, mechanical, mechanical or electrical configuration of the variable valve operating device is not limited in any way as long as at least the opening / closing timing of at least one of the intake and exhaust valves can be changed. At least one of the exhaust camshafts can be configured to change the relative rotational phase of the crankshaft relative to the rotational phase of the crankshaft according to the hydraulic pressure of hydraulic fluid such as oil, for example, in synchronization with the camshaft. The cam shaft may have a configuration in which the rotatable vane rotor is rotated to the advance side or the retard side according to the hydraulic pressure, or is connected to the cam shaft through a helical gear or a helical spline as appropriate. A configuration in which a shaft or piston that can reciprocate in the direction is driven by an actuator that uses hydraulic pressure as a drive source, and these reciprocating motions are converted into rotational motion of the camshaft. It may be. Or, unlike the hydraulic pressure of the hydraulic fluid, it is called a so-called cam-by-wire that includes at least one camshaft or an electric actuator that can advance or retard the cam relative to the crankshaft. Such an electric drive mechanism may be used.

  The output improvement control at the time of high load through such a variable valve device is, for example, that the valve overlap amount of the intake / exhaust valve is increased at the time of high rotation and high load, and the inertial intake is promoted to increase the combustion gas discharge efficiency. Various aspects are taken such as improving the pressure or reducing the valve overlap amount of the intake / exhaust valve at the time of low / medium rotation / high load, and introducing explosive force by introducing as much new air as possible. The control of the valve timing at the time of high load for the purpose of improving the output leads to a decrease in the internal EGR amount or an increase in the combustion temperature. Therefore, it can be said that the control is relatively easy to increase the NOx emission amount.

  According to this aspect, when it is determined that the NOx emission should be suppressed, the operation of the variable valve operating apparatus at such a high load is prohibited. Therefore, in the above example, the valve overlap amount of the intake / exhaust valve relatively increases at low, medium and high loads, and the internal EGR is promoted to lower the combustion temperature, thereby reducing the NOx emission amount. . Alternatively, the valve overlap amount is reduced at the time of high rotation and high load, and the intake / exhaust efficiency is relatively lowered, so that the NOx emission amount is reduced. When controlling the variable valve system for the purpose of improving the output at high loads, the combustion temperature rises and the amount of NOx emissions increases. Therefore, no matter what control mode is used at high loads, the variable valve apparatus operates. By being banned, NOx emissions are somewhat reduced.

  Therefore, according to this aspect, similarly to the ignition timing described above, when NOx emission is to be suppressed, the NOx emission amount can be reduced while the vehicle is kept running, which is beneficial in practice.

  In another aspect of the control device for an internal combustion engine according to the present invention, the internal combustion engine includes an injection device capable of injecting fuel, and the control means determines that the NOx emission should be suppressed. When performed, the injection device is controlled so that the injection amount related to the injection does not increase with respect to the reference injection amount corresponding to the stoichiometric air-fuel ratio.

  According to this aspect, the internal combustion engine is provided with the injection device capable of injecting fuel, and the control means controls the injection device so that the injection amount related to the injection does not increase with respect to the reference injection amount corresponding to the stoichiometric air-fuel ratio. By doing so, it is possible to effectively reduce the emission amount of NOx.

  Here, the “reference injection amount corresponding to the stoichiometric air-fuel ratio” includes an injection amount that provides the stoichiometric air-fuel ratio as a preferred form, and is used for normal air-fuel ratio control during actual operation of the internal combustion engine. It is a concept that also includes an injection amount that matches the air-fuel ratio in the vicinity of the theoretical air-fuel ratio.From another aspect, it is normally set in situations where the output is likely to be prioritized over fuel consumption qualitatively, such as at high loads. It is a concept that does not include an injection amount corresponding to an air-fuel ratio that is clearly lower than the stoichiometric air-fuel ratio, that is, an air-fuel ratio on the rich side. That is, as a preferred mode for controlling the injection device so that the injection amount does not increase with respect to the reference injection amount as such a purpose, the air-fuel ratio is a value in the vicinity of the theoretical air-fuel ratio or a value on the lean side thereof. In other words, the injection amount is limited so that the air-fuel ratio does not shift to the rich air-fuel ratio even in a transient period.

  Thus, when the stoichiometric air-fuel ratio is ideally used as the air-fuel ratio (except when lean-burn operation is employed), the exhaust gas purification efficiency in various catalytic converters such as three-way catalysts is maximized or the same as that. Therefore, the NOx emission amount is practically suppressed as much as possible. That is, according to this aspect, when NOx emission should be suppressed, the amount of NOx emission can be reduced quickly and effectively.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

<Embodiment of the Invention>
Various preferred embodiments of the present invention will be described below with reference to the drawings.
<First Embodiment>
<Configuration of Embodiment>
First, the configuration of the vehicle 10 according to the present invention will be described with reference to FIG. FIG. 1 is a block diagram conceptually showing a configuration of a part related to the control device for an internal combustion engine according to the present invention in the vehicle 10.

  In FIG. 1, the vehicle 10 includes an ECU 100, an engine 200, a car navigation device 300, a NOx sensor 400, an outside air temperature sensor 500, an ozone sensor 600, and an in-vehicle clock 700.

  The ECU 100 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (not shown) and is configured to be able to control each element of FIG. An electronic control unit configured to function as an example of an “engine control device”. The ECU 100 is configured to be able to execute a NOx reduction process described later according to a control program stored in the ROM.

  The engine 200 is a gasoline engine that is a power source of a vehicle (not shown), and is an example of an “internal combustion engine” according to the present invention. Here, a detailed configuration of the engine 200 will be described with reference to FIG. Here, FIG. 2 is a schematic diagram of the engine 200. 2 that are the same as those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted as appropriate.

  The engine 200 combusts the air-fuel mixture through an ignition operation by an ignition device 202 in which a part of an ignition plug (not shown) is exposed in a combustion chamber in the cylinder 201, and is generated in accordance with an explosion force caused by the combustion. The reciprocating motion of the piston 203 can be converted into the rotational motion of the crankshaft 205 via the connecting rod 204. In the vicinity of the crankshaft 205, a crank position sensor 206 for detecting a crank angle representing the rotation state of the crankshaft 205 is installed. The crank position sensor 206 is electrically connected to the ECU 100, and the ECU 100 grasps the position of the piston 203 based on the crank angle detected by the crank position sensor 206 and controls the ignition timing and the like by the ignition device 202. It is configured to be possible. Further, the ECU 100 is configured to be able to calculate the engine speed Ne of the engine 200 by time-processing the crank angle detected by the crank position sensor 206.

  In the engine 200, the air sucked from the outside (that is, the sucked air) is filtered by the air cleaner 208 in the process of passing through the intake pipe 207. A hot wire type air flow meter 209 is installed in the subsequent stage of the air cleaner 208, and is configured to be able to directly detect the mass flow rate of intake air (hereinafter referred to as “intake air amount” as appropriate). The air flow meter 209 is electrically connected to the ECU 100, and the detected intake air amount is grasped by the ECU 100 constantly or at a constant or indefinite period.

  On the downstream side of the air flow meter 209 in the intake pipe 207, a throttle valve 210 that adjusts the amount of intake air flowing into the cylinder 201 is disposed. The throttle opening, which is the opening of the throttle valve 210, is detected by the throttle position sensor 211, and is constantly grasped by the ECU 100 electrically connected to the throttle position sensor 211, or is grasped at a constant or indefinite period. . The throttle opening is variably controlled by a throttle valve motor 212 that is electrically connected to the ECU 100.

  On the other hand, the depression amount of an accelerator pedal (not shown) by the driver is detected by an accelerator position sensor (not shown) and is grasped by the ECU 100 electrically connected to the accelerator position sensor. The ECU 100 normally controls the throttle valve 210 via the drive control of the throttle valve motor 212 so that a throttle opening corresponding to the amount of depression of the accelerator pedal detected by the accelerator position sensor can be obtained. However, the throttle valve 210 is an electronically controlled throttle valve that is driven by a throttle valve motor 212, and the throttle opening is independent of the driver's intention (that is, the accelerator pedal depression amount) under the control of the ECU 100. Can be variably controlled.

  An injector 213 is installed in an intake port (reference numeral omitted) that continues from the intake pipe 207. The injector 213 is an electronically controlled fuel injection device configured to be able to inject gasoline as fuel into the intake port. The fuel is stored in the fuel tank 214 and is supplied by pressure to the injector 213 via the delivery pipe 215 by the action of the low pressure pump 216. The injector 213 is electrically connected to the ECU 100 and is configured to be able to inject an amount of fuel into the intake port according to the drive duty ratio controlled by the ECU 100. The fuel injected from the injector 213 is mixed with the intake air at the intake port and becomes the above-described mixture. Incidentally, the form of the injection means for injecting the fuel does not have to adopt a so-called intake port injector configuration as illustrated in FIG. 3. For example, the pressure of the fuel pumped by the low pressure pump 216 is further increased by the high pressure pump. Further, it may have a form such as a so-called direct injection injector configured to be able to directly inject fuel into the high-temperature and high-pressure cylinder 201.

  The communication state between the inside of the cylinder 201 and the intake port is controlled by opening and closing the intake valve 217. The exhaust gas, which is the air-fuel mixture combusted inside the cylinder 201, passes through an exhaust valve 218 that opens and closes in conjunction with the opening and closing of the intake valve 217, and is discharged to an exhaust port (reference numeral omitted). The exhaust port communicates with the exhaust pipe 219, and the exhaust gas that has passed through the exhaust port is discharged out of the vehicle 10 through the exhaust pipe 219 and the three-way catalyst 221 installed in the exhaust pipe 219. The three-way catalyst 221 is a catalyst that can purify CO (carbon monoxide), HC (hydrocarbon), and NOx (nitrogen oxide) discharged from the engine 200, respectively.

  On the other hand, the exhaust pipe 219 is provided with an air-fuel ratio sensor 220 capable of detecting an air-fuel ratio at the time of fuel combustion in the engine 200. The detected air-fuel ratio is electrically connected to the air-fuel ratio sensor 220. It is configured to be grasped constantly or at a constant or indefinite period by the connected ECU 100. A water temperature sensor 222 for detecting the temperature of cooling water of the engine 200 such as LLC (Long Life Coolant) is disposed in the water jacket in the cylinder block that accommodates the cylinder 201. Further, the cylinder block is provided with a knock sensor 223 configured to be able to detect block vibration in the cylinder block. The knock sensor 223 and the water temperature sensor 222 are electrically connected to the ECU 100, respectively, and the detected signals indicating the cooling water temperature of the engine 200 and the intensity of block vibration are supplied to the ECU 100.

  Of the valve opening characteristics of the intake valve 217, the lift amount and the operating angle are basically the same as that of the intake cam 225 having an elliptical shape in cross section provided on the intake camshaft 224 that rotates in conjunction with the crankshaft 205. It is uniquely determined according to the cam profile. On the other hand, in the engine 200, the opening / closing characteristics (that is, the valve timing) of the intake cam 225 are variably controlled by the intake side VVT controller 226 connected to the intake camshaft 224. The configuration of the intake side VVT controller 226 may be equivalent to a known VVT mechanism, and detailed illustration thereof is omitted. For example, the intake side VVT controller 226 includes a housing that rotates integrally with the crankshaft 205, And a rotor configured to be rotatable in the housing. At this time, the working fluid is appropriately supplied to the advance chamber and the retard chamber divided by a plurality of vanes provided on the outer peripheral portion of the rotor, so that the rotor rotates inside the housing to the advance side or the retard side. Move. As a result, the intake camshaft 224 that rotates integrally with the rotor rotates relative to the rotational phase of the crankshaft 205 toward the advance side or the retard side, and the valve timing of the intake cam 225 changes. The intake-side VVT controller 226 is electrically connected to the ECU 100, and the operation of the intake-side VVT controller 226 including the above-described hydraulic fluid supply mode and the like is controlled by the ECU 100 in a higher level.

  Of the valve opening characteristics of the exhaust valve 218, the lift amount and the working angle are basically the same as that of the intake cam 228 having an elliptical shape in cross section provided on the exhaust camshaft 227 that rotates in conjunction with the crankshaft 205. It is uniquely determined according to the cam profile. On the other hand, in the engine 200, the opening / closing characteristics (that is, the valve timing) of the exhaust cam 228 are variably controlled by the exhaust side VVT controller 229 connected to the exhaust camshaft 227. The configuration of the exhaust side VVT controller 229 may be the same as that of a known VVT mechanism, and detailed illustration thereof is omitted. For example, the exhaust side VVT controller 229 includes a housing that rotates integrally with the crankshaft 205, And a rotor configured to be rotatable in the housing. At this time, the working fluid is appropriately supplied to the advance chamber and the retard chamber divided by a plurality of vanes provided on the outer peripheral portion of the rotor, so that the rotor rotates inside the housing to the advance side or the retard side. Move. As a result, the exhaust camshaft 227 that rotates integrally with the rotor rotates relative to the rotational phase of the crankshaft 205 toward the advance side or the retard side, and the valve timing of the exhaust cam 228 changes. The exhaust-side VVT controller 229 is electrically connected to the ECU 100, and the operation of the exhaust-side VVT controller 229 including the above-described hydraulic fluid supply mode and the like is controlled by the ECU 100 to the upper level.

  Returning to FIG. 1, the car navigation device 300 is mounted on the vehicle 10. For example, position information of the vehicle 10, road information around the vehicle 10 (for example, road type, road width, number of lanes, speed limit, road shape, etc.) This is an apparatus configured to be able to acquire various navigation information such as information on various facilities installed around the vehicle 10, traffic jam information, and environmental information. The car navigation device 300 includes a navigation processing device 310, a GPS antenna 320, a VICS antenna 330, and a wireless communication device 340.

  The navigation processing device 310 is a control unit that is electrically connected to the ECU 100 and configured to control the entire operation of the car navigation device 300. The navigation processing device 310 analyzes information acquired via the GPS antenna 320, the VICS antenna 330, and the wireless communication device 340, and supplies necessary information as data to the ECU 100 in the execution process of the NOx reduction processing described later. Is configured to be possible.

  The GPS antenna 320 is a communication means configured to be able to receive a GPS signal supplied from a GPS satellite. The GPS signal obtained via the GPS antenna 320 is converted into position information of the vehicle 10 by the navigation processing device 310.

  The VICS antenna 330 is a communication means configured to be able to acquire data related to VICS information mainly including traffic information from radio wave beacons and optical beacons installed as infrastructure equipment on the road. Data relating to the VICS information obtained via the VICS antenna 330 is converted into road information by the navigation processing device 310.

  The wireless communication device 340 is appropriately issued each time, such as data on atmospheric NOx concentration and ozone concentration measured by an atmospheric measurement station, an atmospheric quality measurement station, etc., as well as a photochemical smog warning, a photochemical smog alarm, etc. It is a communication means configured to be able to acquire data related to environmental information representing the announcement state of various notification information related to air pollution from these various measurement stations, various broadcast stations, and the like via wireless communication. This kind of data obtained via the wireless communication device 340 is converted into environmental information by the navigation processing device 310.

  The NOx sensor 400 is a sensor configured to be able to detect the NOx concentration at the current position of the vehicle 10. The NOx sensor 400 is electrically connected to the ECU 100, and the detected NOx concentration is supplied to the ECU 100 as NOx concentration data.

  The outside air temperature sensor 500 is a sensor configured to be able to detect the outside air temperature at the current position of the vehicle 10. The outside air temperature sensor 500 is electrically connected to the ECU 100, and the detected outside air temperature is supplied to the ECU 100 as outside air temperature data.

  The ozone sensor 600 is a sensor configured to be able to detect the ozone concentration at the current position of the vehicle 10. The ozone sensor 600 is electrically connected to the ECU 100, and the detected ozone concentration is supplied to the ECU 100 as ozone concentration data.

  The in-vehicle clock 700 is a clock configured to be able to detect the current time. The on-vehicle clock 700 is electrically connected to the ECU 100, and the detected current time is supplied to the ECU 100 as time data.

<Operation of Embodiment>
Here, with reference to FIG. 3, the details of the NOx reduction processing executed by the ECU 100 will be described as the operation of the present embodiment. FIG. 3 is a flowchart of the NOx reduction process.

  In FIG. 3, the ECU 100 first determines whether the air environment around the vehicle 10 is easily contaminated by air pollutants (whether the air pollutants are likely to be highly concentrated around the vehicle 10). The first determination process related to the setting of the first flag that defines (the concept including) is executed (step S100). The first determination process will be described later. After the first determination process, the ECU 100 determines whether or not the first flag is set to OFF as a result of the first determination process (step S10). The first flag is a flag that is set to ON when it is determined that the atmospheric environment is likely to be polluted, and is set to OFF when it is not.

  When the first flag is set to ON (step S10: NO), the ECU 100 proceeds the process to step S14, and the ignition timing of the air-fuel mixture in the ignition device 202 is always retarded by a fixed amount with respect to the reference ignition timing. The ignition timing retarding control is executed as described above. On the other hand, when the first flag is set to OFF (step S10: YES), the ECU 100 executes a second determination process related to the setting of the second flag that defines the presence state of the NOx suppression target person (step S200). . The second determination process will be described later. After the second determination process, the ECU 100 determines whether or not the second flag is set to OFF as a result of the second determination process (step S11). The second flag is a flag that is set to ON when it is determined that there is a NOx suppression target person around the vehicle 10, and is set to OFF when it is determined that there is no person.

  When the second flag is set to ON (step S11: NO), the ECU 100 proceeds to step S14, executes ignition timing retardation control, and when the second flag is set to OFF (step S14). S11: YES), the ECU 100 further executes a third determination process related to the setting of a third flag that defines whether or not the air pollutant has a high concentration around the vehicle 10 (step S300). The third determination process will be described later. After the third determination process, the ECU 100 determines whether or not the third flag is set to OFF as a result of the third determination process (step S12). The third flag is a flag that is set to ON when the concentration of the air pollutant is high (that is, an example of “the degree of air pollution is high” according to the present invention), and is set to OFF when it is not. .

  When the third flag is set on (step S12: NO), the ECU 100 proceeds to step S14, executes ignition timing retard control, and when the third flag is set off (step). S12: YES), for example, the ECU 100 selects the ignition timing value corresponding to the engine speed NE and the accelerator opening (that is, the load) of the engine 200 at that time from a preset ignition timing map and performs ignition. The normal ignition timing control set as the timing is executed (step S13). If the process which concerns on step S13 or step S14 is performed, a process will be returned to step S100 and a series of processes will be repeated.

  Here, with reference to FIG. 4, the detail of the 1st determination process of step S100 is demonstrated. FIG. 4 is a flowchart of the first determination process.

  In FIG. 4, the ECU 100 acquires from the navigation processing device 310 information related to the vehicle position and information related to traffic jams or congestion around the vehicle 10 (that is, an example of “traffic state” according to the present invention). (Step 101). As described above, the navigation processing device 320 acquires information on the vehicle position from the GPS signal obtained via the GPS antenna 320, and obtains information on the traffic jam from the VICS signal obtained via the VICS antenna 330. It is possible.

  Next, the ECU 100 acquires the current time from the in-vehicle clock 700 (step S102), and acquires the outside air temperature from the outside air temperature sensor 500 (step S103). Note that, in the processing according to steps S101 to S103, an example of the “vehicle running condition” according to the present invention is acquired.

  When the acquisition of these various types of information is completed, the ECU 100 determines whether or not the atmospheric environment around the vehicle 10 is likely to cause photochemical smog (step S104). Specifically, in the process according to step S104, whether or not there is a traffic jam section within a radius of 5 km from the vehicle position, the current time is between 8:00 am and 6:00 pm, and the outside air temperature is 24 ° C. or higher. Is determined. When all of these conditions are satisfied (step S104: YES), the ECU 100 sets the first flag to ON (step S107) and ends the first determination process.

  On the other hand, when the photochemical smog is not likely to occur (step S104: NO), the ECU 100 further determines whether the atmospheric environment around the vehicle 10 is easily contaminated by the atmospheric inversion layer (step S104). S105). Specifically, in the process according to step S105, a congested section or a congested section exists within a radius of 5 km from the own vehicle position, and the current time corresponds to an early morning time zone (for example, from 3 am to 7 am), and It is determined whether or not the outside air temperature is 15 ° C. or lower. When all of these conditions are satisfied (step S105: YES), the ECU 100 sets the first flag to ON (step S107) and ends the first determination process.

  On the other hand, as a result of the determination process in step S105, if the atmospheric environment is not easily contaminated (step S105: NO), the ECU 100 sets the first flag to off (step S106), and ends the first determination process. To do.

  As described above, in the first determination process, when the atmospheric environment around the vehicle 10 is in a state in which photochemical smog is likely to be generated or is easily contaminated by the atmospheric inversion layer, the atmospheric environment is A determination is made that it is easily contaminated (or that the concentration of air pollutants is likely to increase), and the first flag is set to ON. Here, a radius of 5 km from the own vehicle position is the estimated range of the atmospheric environment around the vehicle 10, but the definition of “around the vehicle 10” is not particularly limited, for example, a radius of 1 km from the own vehicle position Or a range of 10 km. In addition, the extent to which the vehicle position is targeted may be set, for example, by an input from the driver each time, or each time the ECU 100 considers the regional characteristics to which the vehicle position belongs, etc. It may be set individually and specifically. In addition, the range is not necessarily centered on the vehicle 10.

  Next, the details of the second determination process according to step S200 will be described with reference to FIG. FIG. 5 is a flowchart of the second determination process.

  In FIG. 5, the ECU 100 acquires information on the position of the host vehicle and facility information around the vehicle 10 from the navigation processing device 310 (step S201). The navigation processing device 310 holds various map data in which information on various facilities is described in a mass storage device such as an HDD (Hrad Disk Drive) in advance, and is obtained via the GPS antenna 320. Based on the data on the vehicle position, it is possible to supply the ECU 100 with information related to facilities around the vehicle 10.

  Next, the ECU 100 is within a radius of 5 km from the position of the vehicle, various schools such as kindergartens, nursery schools, nursing schools and elementary and junior high schools, facilities for the physically handicapped, facilities for the mentally ill, hospitals, clinics and hospices, In addition, it is determined whether or not there are various facilities that can be associated with the presence of the NOx suppression target person, such as facilities for elderly people such as care plazas and nursing homes (step S202).

When such a facility exists (step S202: YES), the ECU 100 sets the second flag to ON (step S203), and when such a facility does not exist within a radius of 5 km from the vehicle position (step S202). : NO), ECU 100 sets the second flag to OFF (step S204), and ends the second determination process.

  Thus, in the second determination process, when there are various facilities around the vehicle 10 that can be determined with a high probability that there is a NOx suppression target person, the second flag is set to ON. Here, a radius of 5 km from the vehicle position is the detection range of the facility corresponding to the NOx suppression target person as the periphery of the vehicle 10, but the definition of “around the vehicle 10” is not particularly limited. It may be within a range of 1 km radius or 10 km from the vehicle position. In addition, the extent to which the vehicle position is targeted may be set, for example, by an input from the driver each time, or each time the ECU 100 considers the regional characteristics to which the vehicle position belongs, etc. It may be set individually and specifically. In addition, the range is not necessarily centered on the vehicle 10.

  Next, the details of the third determination process according to step S300 will be described with reference to FIG. FIG. 6 is a flowchart of the third determination process.

  In FIG. 6, the information regarding the own vehicle position is acquired from the navigation processing device 310 (step S301). Next, the ECU 100 obtains, from the navigation processing device 310, information related to the alarm status or warning information regarding atmospheric pollution such as photochemical smog, and information related to NOx concentration and ozone concentration at each measurement point measured by the atmospheric measurement station. Obtain (step S302). Note that if there is no corresponding measurement point or significant information regarding the concentration at the corresponding measurement point cannot be obtained, the determination process according to step S303 is skipped, and the process proceeds to step S304.

  When these pieces of information are acquired, the ECU 100 determines whether or not the vehicle position belongs to a warning or warning issuing area (step S302). If it is determined that the current position belongs to the instruction area (step S302: YES), the ECU 100 proceeds to step S307, sets the third flag to ON, and ends the third determination process. On the other hand, when it is determined that the vehicle does not belong to the designated area, or when an alarm or warning regarding air pollution is not issued (step S302: NO), the ECU 100 performs measurement within a radius of 5 km from the vehicle position. It is determined whether the NOx concentration or the ozone concentration measured by the atmospheric measurement station at the point is less than the atmospheric environment reference value (for example, 0.06 ppm) (step S303). If these concentrations are equal to or higher than the atmospheric environment reference value (step S303: NO), the ECU 100 proceeds to step S307, sets the third flag to ON, and ends the third determination process.

  On the other hand, when these concentrations are less than the atmospheric environment reference value (step S303: YES), the ECU 100 acquires the NOx concentration and the ozone concentration at the vehicle position from the NOx sensor 400 and the ozone sensor 600 (step S304), It is determined whether or not the concentration at the vehicle position is less than the above-mentioned atmospheric environment reference value (step S305). When the concentration at the vehicle position is equal to or higher than the atmospheric environment reference value (step S305: NO), the ECU 100 sets the third flag on (step S307), and when the concentration is less than the atmospheric environment reference value. (Step S305: YES), ECU 100 sets the third flag to OFF (Step S306), and ends the third determination process.

  Thus, in the third determination process, the atmospheric environment around the vehicle 10 is already contaminated to a level that cannot be ignored in practice, or includes a case where it is certain that it will be contaminated. When the degree of air pollution is high, the third flag is set on. Here, a radius of 5 km from the position of the vehicle is used as the detection range of the measurement point of the atmospheric measurement station as the surroundings of the vehicle 10, but the definition of “around the vehicle 10” is not particularly limited. It may be within a range of 1 km radius or 10 km from the vehicle position. In addition, the extent to which the vehicle position is targeted may be set, for example, by an input from the driver each time, or each time the ECU 100 considers the regional characteristics to which the vehicle position belongs, etc. It may be set individually and specifically. In addition, the range is not necessarily centered on the vehicle 10. Similarly, the reference value used for comparison with these concentrations may not necessarily be a numerical value that can be administratively defined, such as the atmospheric environment reference value.

The NOx reduction process according to the present embodiment is performed when the flag is set to ON in any of the first, second, and third determination processes, that is, when the atmospheric environment is easily contaminated. In cases where it is considered that there is a person who is subject to NOx suppression, or where air pollution is progressing to a level that cannot be ignored in practice, the situation stipulates that NOx emissions should be suppressed, or irregularly Ignition timing retarding control is executed in various situations including situations where the NOx emission to be visited should be significantly reduced. When the ignition timing is retarded by the ignition timing retarding control, the ignition timing is always retarded as compared with the ignition timing according to the normal ignition timing control according to step S13, so the combustion temperature in the cylinder of the engine 200 is The NOx generation is suppressed and the NOx emission amount is finally reduced. That is, by reducing the amount of NOx emission in such a situation, it becomes possible to protect the air environment or the NOx suppression target person from air pollutants. At this time, the ignition timing of the vehicle 10 is only retarded, and at least its traveling is not hindered, whether or not the required output is satisfied. Thus, according to this embodiment, NOx emission is effectively and effectively suppressed.
Second Embodiment
As a method of suppressing the NOx emission amount, other than the ignition timing retardation control according to the first embodiment may be considered. Here, the NOx reduction processing according to the second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a flowchart of the NOx reduction process according to the second embodiment. In the figure, the same reference numerals are given to the same portions as those in FIG. 3, and the description thereof will be omitted as appropriate.

  In FIG. 7, any of the first flag, the second flag, or the third flag is turned on through the first determination process (step S100), the second determination process (step S200), and the third determination process (step S300) as appropriate. (Ie, step S10: NO, step S11: NO, or step S12: NO), the ECU 100 prohibits the intake side VVT controller 226 and the exhaust side VVT controller 229 from operating in a high load region ( Step S21). That is, when the engine 200 is operating in a high load region, the ECU 100 stops these VVT controllers for control. On the other hand, when both of these flags are set to OFF, the valve timings of the intake valve 217 and the exhaust valve 218 are variably controlled according to normal valve timing control (step S20). In this embodiment, the valve timing can be controlled for both intake and exhaust. However, the VVT controller may be installed only on the intake side, for example. In this case, only the valve timing of the intake valve 217 is variable. Be controlled.

  Here, when normal valve timing control is performed, the ECU 100 basically prioritizes the improvement of the output over the improvement of the fuel consumption in the high load region. For example, the VVT controller is controlled so that the valve overlap amount of the intake / exhaust valve is increased when the engine speed NE is correspondingly high and the engine speed is high, and the inertial intake is promoted to increase the combustion gas discharge efficiency. By improving the output, the output can be improved. In addition, when the load is high in the low / medium rotation region that is not the high rotation region, the valve overlap amount of the intake / exhaust valve is reduced, and the output is improved by introducing as much fresh air as possible. That is, the control of the valve timing at the time of high load for the purpose of improving the output causes a decrease in the internal EGR amount or an increase in the combustion temperature, and the NOx emission amount tends to increase relatively.

  Thus, by prohibiting the operation of the VVT controller at the time of high load in this way, for example, the valve overlap amount of the intake and exhaust valves is relatively increased at the time of low to medium rotation and high load, and the internal EGR is promoted and combustion is performed. As the temperature decreases, the amount of NOx emission decreases. Alternatively, the valve overlap amount is reduced at the time of high rotation and high load, and the intake / exhaust efficiency is relatively lowered, so that the NOx emission amount is reduced. The above-described control is an example of valve timing control. However, when the engine 200 is in a high load state and the VVT controller is controlled for the purpose of improving the output, the combustion temperature rises and the NOx emission amount is Therefore, the NOx emission amount decreases by prohibiting the valve timing control through the control of the VVT controller.

As described above, according to the second embodiment, it is possible to reduce the NOx emission amount without performing the ignition timing retardation control.
<Third Embodiment>
As a method for suppressing the NOx emission amount, other than the ignition timing retardation control and the VVT operation prohibition control according to the first and second embodiments may be considered. Here, the NOx reduction processing according to the third embodiment of the present invention will be described with reference to FIG. FIG. 8 is a flowchart of the NOx reduction process according to the third embodiment. In the figure, the same reference numerals are given to the same portions as those in FIG. 3, and the description thereof will be omitted as appropriate.

  In FIG. 8, any of the first flag, the second flag, or the third flag is turned on through the first determination process (step S100), the second determination process (step S200), and the third determination process (step S300) as appropriate. (Ie, step S10: NO, step S11: NO, or step S12: NO), the ECU 100 limits the change in the air-fuel ratio of the engine 200 via the injection amount control of the injector 213 (step S31). ). On the other hand, when both of these flags are set to OFF, ECU 100 controls the fuel injection amount via injector 213 in accordance with normal air-fuel ratio feedback control (step S30).

  Here, the engine 200 normally performs air-fuel ratio feedback control based on the exhaust air-fuel ratio detected by the air-fuel ratio sensor 220 so that the air-fuel ratio converges in the vicinity of the stoichiometric air-fuel ratio (approximately 14.6). It has been broken. However, in an operation region where output is remarkably required, such as the above-described high load region, combustion is performed at a richer air-fuel ratio (for example, about 12 to 13) than the stoichiometric air-fuel ratio. On the other hand, the exhaust purification efficiency of the three-way catalyst 221 is optimized in the vicinity of the theoretical air-fuel ratio. Therefore, when combustion is performed according to the rich air-fuel ratio in this way, the exhaust purification efficiency of the three-way catalyst 221 is relatively high. And NOx purification efficiency also decreases.

  In view of this point, in the processing according to step S31, the air-fuel ratio is generally limited to the vicinity of the stoichiometric air-fuel ratio regardless of the operating conditions of the engine 200. For this reason, the NOx emission amount is relatively reduced as compared with a case where the combustion mode according to the rich side air-fuel ratio is temporarily taken. As described above, according to the third embodiment, it is possible to reduce the NOx emission amount without performing ignition timing retardation control and without performing valve timing control.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and the control of the internal combustion engine accompanying such a change. The apparatus is also included in the technical scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram conceptually showing a configuration of a portion related to a control device for an internal combustion engine according to the present invention in a vehicle according to a first embodiment of the present invention. It is a schematic diagram of the engine with which the vehicle of FIG. 1 is equipped. 2 is a flowchart of NOx reduction processing executed by an ECU in the vehicle of FIG. It is a flowchart of the 1st determination process performed in the NOx reduction process of FIG. It is a flowchart of the 2nd determination process performed in the NOx reduction process of FIG. It is a flowchart of the 3rd determination process performed in the NOx reduction process of FIG. It is a flowchart of the NOx reduction process which concerns on 2nd Embodiment of this invention. It is a flowchart of the NOx reduction process which concerns on 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 100 ... ECU, 200 ... Engine, 300 ... Car navigation apparatus, 310 ... Navigation processing apparatus, 320 ... GPS antenna, 330 ... VICS antenna, 340 ... Wireless communication apparatus, 400 ... NOx sensor, 500 ... Outside temperature sensor , 600... Ozone sensor, 700.

Claims (7)

A control device for an internal combustion engine for controlling the internal combustion engine in a vehicle including the internal combustion engine,
A specifying means for specifying a predetermined type of traveling condition associated with whether or not NOx is discharged in the vehicle;
A discriminating means for discriminating whether or not to suppress the emission of NOx based on the specified traveling condition;
Control means for controlling the internal combustion engine so that the NOx emission amount is at least relatively reduced when the determination that the NOx emission should be suppressed is made. Control device for internal combustion engine. The specifying means specifies at least a traffic state, a current time, and an air temperature within a predetermined range including the vehicle as the running condition,
The determination means indicates that the NOx emission should be suppressed when the specified traffic condition, current time, and temperature satisfy a first condition that is defined in advance as air pollution is likely to proceed. The control device for an internal combustion engine according to claim 1, wherein the determination is performed. The specifying means specifies at least the presence state of the NOx suppression target person within a predetermined range including the vehicle as the running condition,
The discriminating means should suppress the NOx emission when the specified presence condition satisfies a second condition defined in advance as the presence of the NOx suppression target person within the predetermined range. The control device for an internal combustion engine according to claim 1 or 2, wherein the determination is made. The specifying means specifies at least one of a concentration of air pollutants within a predetermined range including the vehicle and an announcement state of notification information on air pollution as the running condition,
The discriminating means discriminates that the NOx emission should be suppressed when at least one of the specified conditions satisfies a third condition defined in advance as a high degree of air pollution. The control apparatus for an internal combustion engine according to any one of claims 1 to 3. The internal combustion engine includes an ignition device for igniting an air-fuel mixture,
The control means controls the ignition device so that the ignition timing related to the ignition is retarded with respect to the reference ignition timing when it is determined that the NOx emission should be suppressed. The control device for an internal combustion engine according to any one of claims 1 to 4, wherein: The internal combustion engine includes a variable valve gear capable of changing an opening / closing timing of at least one of an intake valve and an exhaust valve so that an output of the internal combustion engine is improved at least under a high load,
6. The control device according to claim 1, wherein, when it is determined that the NOx emission should be suppressed, the control unit prohibits the operation of the variable valve operating apparatus at the time of the high load. The control apparatus for an internal combustion engine according to claim 1. The internal combustion engine includes an injection device capable of injecting fuel,
The control means controls the injection device so that the injection amount related to the injection does not increase with respect to the reference injection amount corresponding to the stoichiometric air-fuel ratio when it is determined that the NOx emission should be suppressed. The control device for an internal combustion engine according to any one of claims 1 to 6, wherein:

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