JP2010242724A - Control device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent leakage without reducing the effect of an electric heating type catalyst device, in a vehicle having the electric heating type catalyst device. <P>SOLUTION: In a hybrid vehicle 10, an ECU 100 executes scavenging control to EHC. In the control, the ECU 100 acquires an engine stopping time Ts being the length of time when an engine 200 stops, and introduces suction air to an exhaust pipe 212 via a scavenging passage 217 from an intake pipe 203 by controlling driving of an electric air pump 500 while the engine 200 stops when the acquired engine stopping time Ts is a reference value Tsth or more. The exhaust pipe 212 is scavenged by the suction air introduced from this intake pipe 203, and a condensate generated by condensing moisture in exhaust gas, is blown off downstream of the EHC 400. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a technical field of a vehicle control device that controls a vehicle including an electrically heated catalyst device such as EHC (Electric Heating Catalyst).

  An apparatus for preventing EHC leakage has been proposed (see, for example, Patent Document 1). According to the exhaust gas purification apparatus for an internal combustion engine disclosed in Patent Document 1, an upstream catalyst carrier having a heater function and a downstream catalyst carrier are provided, and a part of the exhaust gas is diverted to the downstream catalyst carrier while bypassing the upstream catalyst carrier. In the configuration in which the temperature increase of the downstream catalyst carrier is promoted by providing a bypass passage that leads, the positive electrode of the heater in the upstream catalyst carrier is disposed above the bypass passage, so that moisture condensed in the bypass passage is transferred to the positive electrode. It is said that it is possible to prevent electric leakage due to outflow.

  In addition, some hybrid vehicles have been proposed in which EHC is energized when the engine is started due to a decrease in SOC during EV travel (see, for example, Patent Document 2).

JP-A-8-210217 Japanese Patent Laid-Open No. 10-288028

  The burned gas contains water as one component, and in an internal combustion engine that has been in a cold state for a long period of time, condensed water tends to be generated, particularly in the exhaust passage. Therefore, in a vehicle equipped with an electrically heated catalyst device, when the EHC is energized to promote catalyst warm-up when the internal combustion engine is started after a relatively long non-operation period, this condensed water is used. Electric leakage may occur.

  When power leakage occurs, or when power is supplied in spite of the possibility of leakage, first of all, power resources may be wasted. Secondly, due to the fact that the vehicle body (body or chassis) or the exhaust passage can be charged, for example, when the driver contacts the body during driving, a kind of electric shock occurs to some extent. there is a possibility.

  According to the apparatus disclosed in Patent Document 1, although the electrode installation position has been devised in consideration of the possibility of electric leakage, the occurrence of electric leakage or cracks caused mainly by condensed water generated in the exhaust passage, There are limits to what can be prevented by this type of hardware alone. In addition, if the electric heating type catalyst device is frequently restricted for the purpose of simply avoiding electric leakage, the emission reduction at the start of the internal combustion engine will be insufficient, and the electric heating type catalyst device will be installed. The significance of doing it will fade. Further, the device of Patent Document 2 has no suggestion about such a leakage, and it must be said that it is impossible to prevent this kind of leakage.

  As described above, various conventional apparatuses including the above-described prior art have a technical problem that it is difficult to avoid electric leakage while sufficiently ensuring the exhaust purification performance required for the electrically heated catalyst apparatus. . This invention is made in view of the problem which concerns, and makes it a subject to provide the control apparatus of the vehicle which can avoid a leak reliably, without reducing the effectiveness of an electrically heated catalyst apparatus.

  In order to solve the above-described problems, a vehicle control device according to the present invention includes an internal combustion engine, an electrically heated catalyst device installed in an exhaust passage of the internal combustion engine and generating heat when energized, and an air flow in the exhaust passage. A control device for a vehicle comprising an air flow generation means capable of generating, an acquisition means for acquiring a predetermined determination index value associated with the amount of condensed water generated in the exhaust passage, and the acquired determination Determining means for determining whether or not the generated amount is greater than or equal to a reference value based on an index value; and when it is determined that the internal combustion engine is in a stopped state and the generated amount is greater than or equal to the reference value, And a first control unit that controls the air flow generation unit so that the air flow is generated.

  The vehicle according to the present invention is a vehicle including at least an internal combustion engine, an electrically heated catalyst device, and an air flow generating means. The vehicle control device according to the present invention is a device for controlling the vehicle according to the present invention, and includes, for example, one or a plurality of CPUs (Central Processing Units), MPUs (Micro Processing Units), various processors, or various types. Various processing such as a single or multiple ECUs (Electronic Controlled Units), which may appropriately include various storage means such as a controller or ROM (Read Only Memory), RAM (Random Access Memory), buffer memory or flash memory Various computer systems such as a unit, various controllers or a microcomputer device may be used.

  The internal combustion engine according to the present invention means an engine capable of converting the combustion of fuel into mechanical power. For example, the fuel type (for example, gasoline, light oil, alcohol, alcohol mixed fuel or natural gas), the fuel There are no particular limitations on the physical, mechanical, or electrical configuration, such as the supply mode, fuel combustion mode, intake / exhaust system configuration, and cylinder arrangement.

  The electrically heated catalyst device according to the present invention is a heater installed in the exhaust passage of the internal combustion engine as a catalyst device for purifying the exhaust gas of the internal combustion engine and a heater for warming up the catalyst device by a heat generation action accompanying energization. The exhaust gas purifying device having at least a function as a general concept is included, and the physical, mechanical, electrical, magnetic, and chemical configurations are not limited at all within the scope of the concept.

  For example, the electrically heated catalyst device may have a structure in which the catalyst device itself has a heater function, for example, because the catalyst carrier is composed of an electric resistor having a relatively high electric resistance, or the heater is a catalyst carrier. The catalyst carrier may be arranged close to the outer peripheral part or the upstream / downstream part of the catalyst and warm up the catalyst carrier by conduction heat or radiant heat. In addition, the electric heating type catalyst device may appropriately include various power sources such as a battery, a power supply circuit, a power supply wiring, and various controllers and control devices for controlling the supplied power as practical aspects. Is not necessarily installed in the exhaust passage.

  The air flow generation means according to the present invention is a concept that includes means capable of generating an air flow in the exhaust passage, for example, an electric or mechanical pump device capable of sending compressed air to the exhaust passage, It can take the form of a cranking motor or various rotating electric machines that can motor the internal combustion engine.

  According to the vehicle control apparatus of the present invention, during the operation, the acquisition unit acquires a predetermined determination index value associated with the amount of condensed water generated in the exhaust passage.

  Here, the “determination index value” according to the present invention is, for example, experimentally, empirically, theoretically or based on simulation in advance, for example, condensed water generated by condensation of moisture in the exhaust gas. It is a value in which a one-to-one, one-to-many, many-to-one or many-to-many correspondence is established between the generated amount, for example, the amount of condensed water generated itself, the stop time of the internal combustion engine, the parking time of the vehicle, It may be the maximum temperature of the exhaust passage or the electrically heated catalyst device in the previous trip, or the load condition (for example, the integrated value of the intake air amount) of the internal combustion engine in the previous trip. In addition, the acquired determination index value is not necessarily a single value. For example, in addition to one determination index value, another determination index that functions as a parameter that can change a determination criterion for the one determination index value. A value may be obtained.

  When the determination index value is acquired, the determination unit determines whether or not the amount of condensed water generated is greater than or equal to a reference value based on the acquired determination index value. As described above, since the determination index value is a value in which a correspondence relationship is established in advance with the amount of condensed water generated, the determination unit determines whether the acquired determination index value and the reference value (the determination index value is condensed water). This determination can be made on the basis of a comparison with the standard value of the condensed water (except for the case where the amount of the generated water itself is different).

  In the determination index value and the amount of condensed water generated, one increase may correspond to the other increase, and one increase may correspond to the other decrease. Further, the determination means may execute the determination at a constant or indefinite period, or under a specific condition (for example, when the internal combustion engine is in a stopped state) so that the determination can be practically significant. B) The above determination may be performed.

  When the internal combustion engine is in a stopped state, no gas flow is formed in the exhaust passage, so that the condensed water generated in the exhaust passage stays in the exhaust passage. Further, in such a stopped state, the generation of condensed water can be promoted more significantly in the process of naturally cooling the internal combustion engine. If these points are taken into consideration, the condensate in the exhaust passage significantly affects the electrical insulation characteristics of the electrically heated catalyst device (that is, it infiltrates with the condensate to such an extent that leakage occurs when energized). This is a period in which the internal combustion engine is in a stopped state, and from the viewpoint of increasing the efficiency of the operation, the obtaining unit and the determining unit may execute each operation when the internal combustion engine is in the stopped state.

  On the other hand, according to the vehicle control apparatus of the present invention, when the first control means determines that the internal combustion engine is in a stopped state and the determination means determines that the amount of condensed water produced is greater than or equal to a predetermined value, the air The flow generation means is controlled to generate an air flow in the exhaust passage.

  If an air flow is generated in the exhaust passage, the exhaust passage is scavenged by this air flow, and the condensed water staying in the exhaust passage is preferably at least downstream of the electrically heated catalyst device by this air flow. Is discharged outside the vehicle.

  Further, such scavenging of the exhaust passage is performed during a stop period of the internal combustion engine in which no gas flow is formed in the exhaust passage (if the internal combustion engine is in operation, a gas flow is formed in the exhaust passage, Since no scavenging is required), it is possible to remove the leakage factor in the electrically heated catalyst device before the request to energize the electrically heated catalyst device occurs, which limits the power to the electrically heated catalyst device. For example, there is almost no situation where the efficacy is reduced. That is, according to the vehicle control device of the present invention, it is possible to prevent the occurrence of electric leakage without reducing the effectiveness of the electrically heated catalyst device.

  Note that the generated air is between the “reference value” determined for the amount of condensed water generated and the driving conditions of the air flow generating means (for example, the flow rate, flow rate or generation time of the generated air flow). Corresponding relationships may be defined so that the exhaust passage can eventually be scavenged to a level that does not cause a problem in practice.

  For example, if there is a physical, mechanical or electrical restriction in advance in the driving condition of the air flow generating means, or a realistic restriction that takes into account the consumption of energy resources, etc., at least within the range of the driving condition. It is desirable that the reference value is determined so that the exhaust passage can be surely scavenged (that is, the condensed water in the vicinity of the electrically heated catalyst device can be surely blown downstream). Further, even in the process of generating the air flow by the air flow generating means, there is a case where energization is required for the electrically heated catalyst device depending on the driving conditions of the vehicle. In view of that, it is desirable that the reference value related to the amount of condensed water generated is a value within a range in which no electric leakage can occur in the electrically heated catalyst device when energized.

  Note that the state of the vehicle when the internal combustion engine is in a stopped state may differ depending on the mode of the drive device that drives the vehicle. For example, in a configuration in which the vehicle includes only an internal combustion engine as a power source, the stopped state of the internal combustion engine means a stopped state of the vehicle, and the vehicle can generally correspond to either a stopped state or a parked state. On the other hand, when the vehicle is a hybrid vehicle that includes a rotating electric machine in addition to the internal combustion engine as a power source, the internal combustion engine may be stopped in some cases even during a period in which so-called EV traveling is performed only by the power of the rotating electric machine. . That is, in a hybrid vehicle, the vehicle itself can take a running state even when the internal combustion engine is in a stopped state.

  In one aspect of the vehicle control apparatus according to the present invention, the air flow generating means is a motoring device capable of motoring the internal combustion engine or a pump device capable of pumping air to the exhaust passage.

  According to this type of motoring device or pump device, it is possible to generate an air flow in the exhaust passage in a relatively simple manner, and the scale of the generated air flow is variably controlled stepwise or continuously. It is preferable because it is relatively easy to do.

  In another aspect of the vehicle control apparatus according to the present invention, the acquisition unit acquires the duration of the stop state as the determination index value, and the determination unit exceeds the acquired duration for a predetermined value. If it is determined that the generation amount is greater than or equal to the reference value.

  The duration of the stop state of the internal combustion engine (hereinafter referred to as “stop duration” as appropriate) has a high correlation with the amount of condensed water produced, and determines whether the amount produced is equal to or greater than a reference value. This is suitable as a judgment index value to be referred to. The stop continuation time may include a time during which the vehicle is stopped, that is, a parking time.

  In another aspect of the vehicle control apparatus according to the present invention, the vehicle control apparatus further includes second control means for controlling the electric heating catalyst device so that the energization is started before and after the air flow is generated. It has.

  According to this aspect, prior to the start of the generation of the air flow, in synchronization with the start of the generation of the air flow, or a kind of control trigger that the generation of the air flow is started. As a result, the second control means starts energization of the electrically heated catalyst device at an appropriate timing. For this reason, evaporation of condensed water is promoted by radiant heat or conduction heat from the electrically heated catalyst device, and discharge of condensed water by an air flow is assisted. That is, when both cooperate, a higher scavenging effect can be obtained.

  In addition, the energization conditions for the electrically heated catalyst device at this time may be variable or fixed depending on the control conditions of the air flow generating means. Further, in view of the point that the electric heating type catalyst device is energized in this way, the reference value set for the amount of condensed water generated is a value smaller than the amount of generation that may cause a leakage during energization. Is desirable.

  In another aspect of the vehicle control apparatus according to the present invention, the vehicle includes a rotating electrical machine, a first rotating element coupled to a rotating shaft of the rotating electrical machine, and a second coupled to a drive shaft coupled to the axle. A power transmission mechanism having a plurality of rotating elements capable of differentially rotating with each other including a rotating element and a third rotating element connected to a rotating shaft of the internal combustion engine, wherein the first control means is The rotating electrical machine is controlled as the air flow generating means.

  In this type of hybrid vehicle, if the rotational speed of the drive shaft is unchanged, the rotational change of the rotating electrical machine causes the rotational change of the internal combustion engine due to the differential action of the power transmission mechanism. For this reason, it is possible to easily generate the air flow by motoring the internal combustion engine by the rotating electric machine. Furthermore, if the configuration is such that other rotating electrical machines are connected to the drive shaft, whether directly or indirectly, for example, by the input / output of power between the other rotating electrical machines and the drive shaft, Since the EV traveling by only the power of the rotating electric machine can be possible, the operating frequency of the internal combustion engine can be reduced. Therefore, the condensed water is more easily generated in the exhaust passage. Further, in the case of a so-called PHV (Plug-in Hybrid Vehicle) in which power storage means such as a battery that can input and output electric power with the rotating electrical machine is configured to be appropriately chargeable by an external power source, further The trend can be more pronounced. In view of such a point, this type of hybrid vehicle can be a suitable application example of the vehicle control device according to the present invention. Needless to say, the effect of the vehicle control device according to the present invention is not limited to this type of hybrid vehicle, but can be achieved even with other hybrid vehicles.

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

1 is a schematic block diagram conceptually showing a configuration of a hybrid vehicle according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view conceptually and schematically illustrating a one-plane configuration of an engine provided in the hybrid vehicle in FIG. 1. FIG. 3 is a schematic cross-sectional view conceptually showing a cross-sectional configuration of EHC along the extension direction of the exhaust pipe in the engine of FIG. 2. It is a flowchart of the EHC scavenging control executed by the ECU. It is a flowchart of the EHC scavenging control which concerns on 2nd Embodiment of this invention. FIG. 6 is a schematic diagram of an EHC applied power setting map referred to in the EHC scavenging control of FIG. 5. It is a flowchart of the EHC scavenging control which concerns on 3rd Embodiment of this invention.

<Embodiment of the Invention>
Hereinafter, various embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
<Configuration of Embodiment>
First, the configuration of the hybrid vehicle 10 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic block diagram conceptually showing the configuration of the hybrid vehicle 10.

  In FIG. 1, a hybrid vehicle 10 includes a speed reduction mechanism 11, a drive wheel 12, an accelerator opening sensor 13, a vehicle speed sensor 14, an ECU 100, an engine 200, a motor generator MG1 (hereinafter abbreviated as “MG1” as appropriate), and a motor generator MG2. (Hereinafter abbreviated as “MG2” as appropriate), a hybrid vehicle as an example of a “vehicle” according to the present invention, including a power split mechanism 300, an EHC 400, an electric air pump 500, a PCU 600, and a battery 700.

  The speed reduction mechanism 11 is a gear mechanism including a differential gear (not shown) and a planetary gear. The speed of the drive shaft (not shown), which is the power output shaft of the power split mechanism 300, is adjusted according to a predetermined reduction ratio. 12 is configured to be able to transmit to an axle connected to the vehicle. Note that the configuration of the speed reduction mechanism is not limited to that of the speed reduction mechanism 11, and various modes can be adopted. For example, the speed reduction mechanism may have a function as a speed change mechanism capable of realizing a plurality of shift speeds by a plurality of clutches and brakes and a planetary gear mechanism.

  The ECU 100 is an electronic control unit that includes a CPU, a ROM, a RAM, and the like and is configured to be able to control the entire operation of the hybrid vehicle 10, and is an example of the “vehicle control device” according to the present invention. The ECU 100 is configured to execute EHC scavenging control described later according to a control program stored in the ROM.

  The ECU 100 is an integrated electronic control unit configured to function as an example of each of “acquisition means”, “discrimination means”, and “first control means” according to the present invention. Are configured to be executed by the ECU 100. However, the physical, mechanical, and electrical configurations of each of the units according to the present invention are not limited to this. For example, each of these units includes a plurality of ECUs, various processing units, various controllers, a microcomputer device, and the like. It may be configured as various computer systems.

  The engine 200 is a gasoline engine as an example of the “internal combustion engine” according to the present invention that can function as a power source of the hybrid vehicle 10. Here, a detailed configuration of the engine 200 will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view conceptually and schematically illustrating the one-plane configuration of the engine 200. In the figure, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof will be omitted as appropriate.

  The engine 200 is an in-line four-cylinder gasoline engine that is an example of an “internal combustion engine” according to the present invention that uses gasoline as fuel. The outline of the engine 200 will be described. The engine 200 has a configuration in which four cylinders 202 are arranged in parallel in a cylinder block 201. A force generated when an air-fuel mixture containing fuel is ignited by an ignition operation of an ignition device (not shown) in each cylinder causes a piston (not shown) to reciprocate in a direction perpendicular to the paper surface, and further via a connecting rod. The crankshaft (none of which is not shown) connected to the piston is converted into a rotational motion. Below, the principal part structure of the engine 200 is demonstrated with a part of the operation | movement.

  The engine 200 according to this embodiment is an in-line four-cylinder gasoline engine in which four cylinders 202 are arranged in parallel in a direction perpendicular to the paper surface in FIG. 1, but the configuration of the individual cylinders 202 is equal to each other. Here, only one cylinder 202 will be described. Further, the engine 200 in the present embodiment is a gasoline engine, but the “internal combustion engine” according to the present invention may be a diesel engine using light oil as fuel as a preferred form, or alcohol or alcohol mixed An engine using fuel as fuel may also be used.

  When the air-fuel mixture burns in the cylinder 202, the intake air, which is the air sucked from the outside through the air filter, is guided to the intake pipe 203. A throttle valve 204 capable of adjusting the amount of intake air is disposed in the intake pipe 203. The throttle valve 204 is a rotary valve that is configured to be rotatable by a driving force supplied from a throttle valve motor (not shown) that is electrically connected to the ECU 100 and controlled by the ECU 100 in a higher level. The rotation position is continuously controlled from the fully closed position where the upstream and downstream portions of the intake pipe 203 at the boundary are substantially blocked to the fully open position where the intake pipe 203 is communicated almost entirely.

  The intake pipe 203 communicates with the intake manifold 205, and further communicates with the intake port 206 formed in the cylinder block 201 corresponding to each cylinder via the intake manifold 205. On the other hand, the intake air guided to the intake pipe 203 is mixed with EGR gas, which will be described later, at the merging position on the upstream side of the intake manifold 205, and is configured to allow the intake port 206 and the inside of the cylinder to communicate with each other. When the intake valve is opened, it is sucked into the cylinder 202 as intake air.

  In the cylinder 202, gasoline as fuel is injected from a cylinder direct injection type unit injector 207, and the injected fuel is mixed with the intake air in each cylinder, and Become. Although details are omitted, the fuel is stored in a fuel tank (not shown), pumped out of the fuel tank by the action of a feed pump (not shown), and various known modes are provided via a low-pressure pipe (not shown). It is configured to be pumped to a high pressure pump (not shown). This high-pressure pump is configured to be able to supply fuel to the common rail 208.

  The common rail 208 is electrically connected to the ECU 100 and is configured to store high pressure fuel supplied from the upstream side (that is, the high pressure pump side) up to a target rail pressure set by the ECU 100. It is. The common rail 208 is provided with a rail pressure sensor capable of detecting the rail pressure and a pressure limiter for limiting the amount of fuel accumulated so that the rail pressure does not exceed the upper limit value. The illustration is omitted. The unit injector 207 described above is mounted for each cylinder 202, and each unit injector 207 is connected to the common rail 208 via the high-pressure delivery 209.

  The above-mentioned air-fuel mixture is ignited and burned by the ignition operation of the ignition device in the compression process, and is linked to the opening and closing of the intake valve as exhaust gas including burned gas or partially unburned HC and CO due to incomplete combustion. When an exhaust valve (not shown) that opens and closes is opened, the exhaust manifold 211 is guided through an exhaust port 210 formed in the cylinder block 201. The exhaust manifold 211 communicates with the exhaust pipe 212.

  In addition to the exhaust pipe 212, an EGR passage 213 communicates with the exhaust manifold 211. The EGR passage 213 is a metal and hollow tubular member that allows the exhaust manifold 211 and the intake pipe 203 to communicate with each other. The EGR passage 213 is configured to communicate with the intake pipe 203 at the above-described joining position, and is configured to be able to recirculate a part of the exhaust gas to the intake pipe 203 as EGR gas. An EGR cooler 214 is installed in the EGR passage 213. The EGR cooler 214 is a cooling device provided in the EGR passage 213. The EGR cooler 213 is a metallic and hollow tubular member having a cooling water pipe extending around the outer periphery of the engine 200, and is configured to cool the exhaust gas passing through the EGR cooler 214.

  The EGR valve 215 is a valve mechanism including an openable / closable valve body installed in the EGR passage 213 and a driving device that drives the valve body. The valve body of the EGR valve 215 is configured so that the open / close state is continuously changed by the driving device, and the flow rate of the EGR gas flowing through the EGR passage 213, that is, the EGR amount is controlled according to the open / close state. It is configured to be possible. The drive device of the EGR valve 215 is electrically connected to the ECU 100, and the opening / closing state of the valve body of the EGR valve 215 is controlled by the ECU 100 to the upper level.

  A three-way catalyst 216 is installed in the exhaust pipe 212. The three-way catalyst 216 carries a noble metal such as platinum on a basic carrier such as alumina and has a cross section along the radial direction of the exhaust pipe 212 having a honeycomb shape, and a reduction reaction of NOx (nitrogen oxide) in the exhaust. The exhaust emission control device is configured to be able to purify the exhaust gas by causing the oxidation reaction of CO (carbon monoxide) and HC (hydrocarbon) in the exhaust gas to proceed substantially simultaneously.

  The engine 200 includes an EHC 400 as an example of the “electrically heated catalyst device” according to the present invention on the upstream side of the three-way catalyst 216 in the exhaust pipe 212. The EHC 400 will be described later.

  One end of a scavenging passage 217 is connected to the intake pipe 203 on the upstream side of the throttle valve 204. The other end of the scavenging passage 217 is connected to the exhaust manifold 211, and the intake pipe 203 and the exhaust manifold 211 can communicate with each other through the scavenging passage 217. An electric air pump 500 is installed in the scavenging passage 217.

  The electric air pump 500 is a known rotary fluid discharge device using a motor as a drive source and configured to be capable of pumping a portion of intake air from the intake pipe 203 side to the exhaust manifold 211 side. An example of the “air flow generation means” is configured. The electric air pump 500 is configured to be able to pressure-feed intake air from the intake pipe 203 to the exhaust manifold 211 with a discharge amount corresponding to the rotation speed of the motor as a drive source.

  The drive system of the electric air pump 500 (mainly the drive system that drives the motor) is electrically connected to the ECU 100, and the operation state of the electric air pump 500 is controlled to the upper level by the ECU 100.

  In addition, a backflow prevention valve (not shown) is installed between the electric air pump 500 and the exhaust manifold 211 so that a backflow of gas from the exhaust manifold 211 to the intake pipe 203 does not occur. In the present embodiment, the scavenging passage 217 is branched from the intake pipe 203, but the intake air passage corresponding to the scavenging passage 217 may be configured independently of the intake pipe 203. Good.

  Here, the EHC 400 will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view conceptually showing a cross-sectional configuration of the EHC 400 along the extending direction of the exhaust pipe 212. In the figure, the same reference numerals are given to the same portions as those in FIG. 2, and the description thereof will be omitted as appropriate.

  3, the EHC 400 includes a case 410, a heat insulating member 420, an EHC carrier 430, a temperature sensor 440, a positive electrode 450, a positive electrode coating portion 460, a negative electrode 470, and a negative electrode coating portion 480. This is an electrically heated catalyst device as an example of “EHC” according to the above.

  The case 410 is a housing of the EHC 400 made of a metal material, and is connected to the exhaust pipe 212 via a coupling member (not shown) at each of the upstream and downstream ends thereof.

  The heat insulating member 420 is installed so as to cover the inner peripheral surface of the case 410, and has heat insulation and electrical insulation.

  The EHC carrier 430 is a conductive catalyst carrier whose cross section perpendicular to FIG. 3 forms a honeycomb shape. The EHC carrier 430 carries an oxidation catalyst (not shown) so that the exhaust gas passing through the EHC 400 can be appropriately purified. The catalyst supported on the EHC carrier 430 may be a three-way catalyst. In this case, the distribution of the noble metal may be different from that of the three-way catalyst 216 on the downstream side. The engine 200 may have other catalyst devices such as an NSR (Nox Storage Reduction) catalyst in addition to or instead of the three-way catalyst 216.

  The positive electrode 450 is an electrode for applying a positive voltage whose one end is fixed in the vicinity of the end on the exhaust upstream side of the EHC carrier 430. The other end of the positive electrode 450 is connected to a PCU 600 described later. The positive electrode 450 is partially covered with a resin-made positive electrode coating 460 having electrical insulation, and the case 410 and the positive electrode 450 are maintained in an electrically insulated state.

  The upstream temperature sensor 440 is a sensor attached to a portion in the vicinity of the positive electrode 450 in the EHC carrier 430 and configured to detect the upstream EHC temperature as the temperature of the portion. The upstream temperature sensor 440 is electrically connected to the ECU 100, and the detected upstream EHC temperature is referred to by the ECU 100 at a constant or indefinite period.

  The negative electrode 470 is an electrode for supplying a reference potential whose one end is fixed near the end of the EHC carrier 430 on the exhaust downstream side. The other end of the negative electrode 470 is connected to the PCU 600 described later. The negative electrode 470 is partially covered with a resin-made negative electrode coating 480 having electrical insulation, and the case 410 and the negative electrode 470 are maintained in an electrically insulated state.

  The downstream temperature sensor 490 is a sensor attached to the vicinity of the negative electrode 470 in the EHC carrier 430 and configured to detect the downstream EHC temperature as the temperature of the part. The downstream temperature sensor 490 is electrically connected to the ECU 100, and the detected downstream EHC temperature is referred to by the ECU 100 at a constant or indefinite period.

  In the EHC 400 having such a configuration, when a drive voltage Vd, which is a positive applied voltage, is applied to the positive electrode 450 with reference to the potential of the negative electrode 470, a current flows through the conductive EHC carrier 430, and the EHC carrier 430 Generates heat. Due to this heat generation, the temperature rise of the oxidation catalyst carried on the EHC carrier 430 is promoted, and the EHC 400 is configured to promptly shift to the catalyst active state.

  Such a configuration of the EHC 400 is merely an example, and for example, the configuration of the EHC carrier, the attachment mode of each electrode, the control mode, and the like can take various known modes.

  Here, in the EHC 400, a conductive material having a relatively large electric resistance is used as the EHC carrier 430 for the purpose of sufficiently securing the heat capacity. In order to sufficiently generate heat in the EHC carrier 430 having a large heat mass, the EHC 400 generates a drive voltage Vd during normal driving for the purpose of warming up the catalyst by supplying power from the PCU 600 using the battery 700 described later as a power source. The voltage is set to a relatively high voltage of about 200V.

  Returning to FIG. 1, the motor generator MG1 is configured to function as a generator for charging the battery 700 or supplying power to the motor generator MG2, and further as an electric motor for assisting the power of the engine 200. The motor generator is an example of the “rotary electric machine” according to the present invention.

  Motor generator MG2 is a motor generator as another example of the “rotating electric machine” according to the present invention, which is configured to function as an electric motor for assisting the power of engine 200 or as a generator for charging battery 700. It is.

  The motor generator MG1 and the motor generator MG2 are configured as, for example, a synchronous motor generator, and include a rotor having a plurality of permanent magnets on the outer peripheral surface, and a stator wound with a three-phase coil that forms a rotating magnetic field. Prepare. However, other types of motor generators may be used.

  Power split device 300 is a planetary gear mechanism configured to be able to distribute engine torque Te, which is the output power of engine 200, to MG1 and the drive shaft. In addition, since the structure of the power split mechanism 300 can take various well-known aspects, a detailed description thereof is omitted here, but in brief, the power split mechanism 300 includes a sun gear provided at the center, A ring gear concentrically provided on the outer periphery of the sun gear, a plurality of pinion gears disposed between the sun gear and the ring gear and revolving while rotating on the outer periphery of the sun gear, and coupled to an end of the crankshaft 205, And a planetary carrier that supports the rotation shaft of each pinion gear.

  The sun gear is coupled to the rotor (not shown) of the MG 1 via the sun gear shaft, and the ring gear is coupled to the rotor (not shown) of the MG 2 via the drive shaft and the speed reduction mechanism 11. The drive shaft is connected to the axle as described above, and the motor torque supplied from the MG 2 is transmitted to the axle via the drive shaft and the speed reduction mechanism 11, and is similarly transmitted to the wheel 12 via the axle. Is input to the MG 2 via the speed reduction mechanism 11 and the drive shaft. Under such a configuration, the engine torque Te is transmitted to the sun gear and the ring gear by the power carrier mechanism 300 and the pinion gear, and the engine torque Te is divided into two systems.

  At this time, the MG1 can function as a reaction force element by controlling its output torque so as to balance the engine torque Te transmitted to the sun gear, for example. For this reason, according to power split device 300, it is possible to freely control the rotational speed of engine 200 by controlling the rotational speed of MG1. Using this characteristic, in the hybrid vehicle 10, MG1 is used as a rotation speed control device of the engine 200, the operating point of the engine 200 is maintained at, for example, the optimum fuel consumption operating point, and cranking at the time of starting the engine 200 is performed. Etc. are executed.

  Battery 700 is a rechargeable storage battery configured to be able to function as a power supply source related to power for powering motor generator MG1 and motor generator MG2.

  The PCU 600 converts the DC power extracted from the battery 700 into AC power, supplies the AC power to the motor generator MG1 and the motor generator MG2, and converts AC power generated by the motor generator MG1 and the motor generator MG2 into DC power. It includes an inverter (not shown) configured to be able to supply the battery 700, and input / output of power between the battery 700 and each motor generator, or input / output of power between the motor generators (that is, In this case, the electric power control unit is configured to be capable of controlling power transfer between the motor generators without using the battery 700. The PCU 600 is electrically connected to the ECU 100, and its operation is controlled by the ECU 100.

  On the other hand, the PCU 600 is electrically connected to the positive and negative electrodes of the EHC 400, and is configured to be able to supply the DC drive voltage Vd to the positive electrode 450. A drive current Id corresponding to the DC drive voltage Vd is generated in the EHC carrier 430, and the EHC carrier 430 generates heat in accordance with Joule heat generated by the drive current Id and the electric resistance R of the EHC carrier 430. Yes.

  On the other hand, the PCU 600 is also electrically connected to the electric air pump 500 and can appropriately supply a driving voltage to a motor that is a driving source of the electric air pump 500.

  The accelerator opening sensor 13 is a sensor that can detect an accelerator opening Ta that is an operation amount of an accelerator pedal (not shown) in the hybrid vehicle 10. The accelerator opening sensor 13 is electrically connected to the ECU 100, and the detected accelerator opening Ta is referred to by the ECU 100 at a constant or indefinite period. The vehicle speed sensor 14 is a sensor configured to be able to detect the vehicle speed V of the hybrid vehicle 10. The vehicle speed sensor 14 is electrically connected to the ECU 100, and the detected vehicle speed V is referred to by the ECU 100 at a constant or indefinite period.

<Operation of Embodiment>
The exhaust gas of the engine 200 contains moisture as a component. When the temperature of the exhaust pipe 212 is low, this moisture may be deprived of heat by the pipe wall of the exhaust pipe 212 and may be condensed in the exhaust pipe 212. Condensed water generated by this condensation adheres to the pipe wall of the exhaust pipe 212 and causes condensation in the exhaust pipe 212. On the other hand, the EHC 400 is installed in the exhaust pipe 212, and this condensed water can of course adhere to the EHC 400 as well. That is, the EHC 400 can also condense.

  As described above, the EHC 400 is energized by applying the drive voltage Vd between the positive and negative electrodes. For example, the EHC 400 is covered to such an extent that the condensed water covers the positive electrode 450 and the case 410. In the case of watering, the positive electrode 450 and the case 410 are in an electrical continuity state, and there is a possibility that leakage occurs.

  As described above, the normal driving voltage Vd of the EHC 400 is set to a high voltage of about 200 V in order to quickly raise the temperature of the EHC carrier 430 having a large heat mass. It needs to be avoided reliably. On the other hand, the EHC 400 plays a role in reducing emissions when the engine 200 is cold-started. In order to give priority to avoiding this type of leakage, avoiding deterioration of emissions if energization is continuously prohibited when an appropriate energization request is made. It becomes a difficult problem. That is, when an electrically heated catalyst device such as EHC400 is mounted on a vehicle including the hybrid vehicle 10, it is necessary to reliably avoid electric leakage without reducing the effectiveness of the electrically heated catalyst device.

  In the hybrid vehicle 10, such a problem is suitably solved by the EHC scavenging control executed by the ECU 100. Here, the details of the EHC scavenging control will be described with reference to FIG. FIG. 4 is a flowchart of EUC scavenging control.

  In FIG. 4, ECU 100 determines whether engine 200 is in a stopped state (step S101). When engine 200 is not in a stopped state (step S101: NO), for example, when hybrid vehicle 10 is in a traveling state using engine torque Te as at least part of the driving force, when engine 200 is in an idling state, Alternatively, when the engine 200 is operating for driving various electrical accessories even during EV traveling, the ECU 100 stops the electric air pump 500 (step S104). At this time, if the electric air pump 500 is already stopped, step S104 is substantially skipped.

  On the other hand, when engine 200 is in a stopped state (step S101: YES), for example, when hybrid vehicle 10 is in a ready-off state (a state where no vehicle start input is generated), or when engine speed NE is zero, Alternatively, when the EV traveling is performed in a state where the fuel supply to the engine 200 is stopped, the ECU 100 starts counting by the built-in timer from the time when the engine 200 is stopped. The engine stop time Ts (that is, the counting operation of the engine stop time Ts is an example of the operation of the “acquisition means” according to the present invention) is the reference value (that is, the “predetermined value” according to the present invention). It is determined whether or not it is Tsth or more (which is an example) (step S102).

  Here, the engine stop time Ts is adopted as an example of the determination index value according to the present invention, but this is only an example. For example, the parking time of the hybrid vehicle 10, the exhaust pipe 212 or the EHC 400 in the previous trip is used. It may be replaced by the maximum reached temperature or the integrated value of the intake air amount of the engine 200 in the previous trip.

  When the engine stop time Ts is less than the reference value Tsth (step S102: NO), the ECU 100 advances the process to step S104, and when the engine stop time Ts is greater than or equal to the reference value Tsth (step S102: YES) The air pump 500 is operated (step S103). When the electric air pump 500 is operated, a gas flow of intake air from the intake pipe 203 to the exhaust pipe 212 is generated. Therefore, the exhaust pipe 212 is scavenged, and the condensed water remaining in the vicinity of the EHC 400 in the exhaust pipe 212 is also It is discharged further downstream, preferably outside the hybrid vehicle 10. As a result, the occurrence of electric leakage when the EHC 400 is energized is prevented.

  Here, the driving power of the electric air pump 500 is suppressed to an extremely low power that has been determined in advance that the stored power of the battery 700 will not be depleted even if the electric air pump 500 is continuously operated. In the electric air pump 500, whether it is operating or not operating is more important than the precise driving conditions, and it is possible to reduce condensed water as long as an air flow is generated in the exhaust passage even if it is a minute air flow. Therefore, even with such extremely low power, a practically sufficient scavenging effect can be obtained.

  Note that the reference value Tsth used for comparison determination in step S102 may cause a leakage when the amount of condensed water generated is energized to the EHC 400 so that a sufficient scavenging effect can be obtained by such a relatively gentle air flow. The electric air pump 500 is set to a relatively small value from a kind of preventive standpoint so that the electric air pump 500 is operated before the increase. When step S104 or step S103 is executed, the process returns to step S101, and a series of processes is repeated.

Here, when the operation conditions of the hybrid vehicle 10 are not changed at the time when the processing is returned to step S101, step S103 is continuously executed after all, and the electric air pump 500 is continuously operated. Such an operating state of the electric air pump 500 continues until the electric air pump 500 is stopped in step S104, for example, when the engine 200 is started in response to the engine start request. Therefore, according to the present embodiment, even if the EHC 400 is energized when the engine is started, the leakage due to the condensed water hardly occurs.
<Second Embodiment>
Next, EHC scavenging control according to the second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a flowchart of the EHC scavenging control according to the second embodiment. In the figure, the same reference numerals are given to the same portions as those in FIG. 4, and the description thereof will be omitted as appropriate.

  In FIG. 5, when the electric air pump 500 is operated in step S103, the ECU 100 further sets the energization amount of the EHC 400 (step S201), and energizes the EHC 400 according to the set energization amount (step S202). When the EHC 400 is energized, the process is returned to step S101, and the operation of the electric air pump 500 and the energization of the EHC 400 are continued until the engine 200 enters an operating state.

  Here, when setting the energization amount in step S201, the ECU 100 refers to the EHC energization amount setting map. The EHC energization amount setting map is stored in the ROM in advance, and the ECU 100 can always refer to it. Here, the details of the EHC energization amount setting map will be described with reference to FIG. FIG. 6 is a schematic diagram conceptually showing the configuration of the EHC energization amount setting map.

  In FIG. 6, the EHC energization amount setting map has an EHC energization amount Wehc on the vertical axis and the horizontal axis, respectively (in this embodiment, the drive current is determined when the drive voltage Vd is determined. The driving voltage Vd may be set instead of Wehc) and the scavenging time Tc (the operating time of the electric air pump 500). As shown in the figure, the EHC energization amount Wehc is zero until the scavenging time Tc reaches Tc1 (that is, the EHC 400 is placed in a non-energized state), and is linear until the scavenging time Tc reaches Tc1 until Tc2. During the period in which the scavenging time Tc is Tc2 or more and Tc3 or less, the maximum value determined for scavenging is maintained. The maximum value for scavenging is a power value corresponding to a drive voltage on the lower voltage side than the drive voltage Vd (that is, approximately 200 V) of the EHC 400 at the normal time. As described above, if the amount of condensed water corresponding to the reference value Tsth of the engine stop time Ts is not high enough to cause electric leakage, there is practically no problem in energizing the EHC 400. The EHC energization amount Wehc until the scavenging time Tc reaches from Tc2 to Tc3 may be a power value corresponding to the normal drive voltage Vd for warming up the catalyst.

  When the scavenging time Tc reaches TC3, the EHC energization amount Wehc starts decreasing linearly, and when the scavenging time Tc reaches Tc4, the EHC energization amount Wehc becomes zero again. In the EHC energization amount setting map, the correspondence shown in FIG. 6 is described in a numerical state in advance, and the ECU 100 performs the scavenging time Tc (step S103 is first executed every time step S201 is visited). The EHC energization amount Wehc is selectively acquired from the EHC energization amount setting map according to the count from the time point).

Thus, in the second embodiment, scavenging of the exhaust pipe 212 by the electric air pump 500 described in the first embodiment can be executed while promoting the evaporation of the condensed water by the heat generated by the EHC 400. For this reason, the scavenging effect by the electric air pump 500 can be obtained more effectively. In the present embodiment, since the intake air guided to the exhaust pipe 212 by the discharge action of the electric air pump 500 can be heated by the EHC 400, warm air is sent to the downstream side of the EHC 400 compared to the first embodiment. This makes it possible to prevent the inflow of wet air into the exhaust pipe 212 and the generation of condensed water on the downstream side of the exhaust pipe 212, which is useful in practice.
<Third Embodiment>
Next, EHC scavenging control according to the third embodiment of the present invention will be described with reference to FIG. FIG. 7 is a flowchart of the EHC scavenging control according to the third embodiment. In the figure, the same reference numerals are given to the same parts as those in FIG. 4, and the description thereof will be omitted as appropriate. The system configuration according to the third embodiment is not different from the first and second embodiments.

  In FIG. 7, when the engine stop time Ts is equal to or longer than the reference value Tsth (step S102: YES), the ECU 100 replaces the operation of the electric air pump 500 according to the first and second embodiments with the engine 200 from the motor generator MG1. The engine 200 starts motoring by supplying cranking torque to the crankshaft (step S301). By such motoring, the engine 200 enters an operating state (ie, a motoring state) that does not involve fuel combustion.

  In this motoring state, the intake air introduced into the cylinder when the intake valve is opened is discharged to the exhaust manifold 211 when the exhaust valve is opened, so that an air flow is generated in the exhaust pipe 212. Therefore, the scavenging effect of the exhaust pipe 212 can be obtained as in the electric air pump 500 according to the first and second embodiments.

  Here, in view of the point that such a scavenging effect can be suitably achieved by the MG1 originally provided in the hybrid vehicle 10, the scavenging passage 217 and the electric air pump 500 are not necessarily installed in the third embodiment. It is also possible to obtain practically beneficial incidental effects such as cost reduction and prevention of system configuration enlargement.

  On the other hand, in this embodiment, when motoring is started in step S301, it is determined in step S302 whether or not the scavenging time Tc is less than the reference value Tcth. The reference value Tcth is a value obtained experimentally in advance as a time value corresponding to the fact that scavenging of the exhaust pipe 212 is sufficiently completed. When the scavenging time Tc is less than the reference value Tcth (step S302: YES), that is, when scavenging is still insufficient, the process returns to step S101, and the scavenging time Tc is equal to or greater than the reference value Tcth. (Step S302: NO), that is, when it is determined that scavenging of the exhaust pipe 212 has been sufficiently completed, the engine stop time Ts is reset (Step S303), and motoring is stopped (Step S304). If it is determined in step S101 that the engine is not stopped (step S101: NO), the process proceeds to step S304. When step S304 is executed, the process returns to step S101, and a series of processes is repeated. The EHC scavenging control according to the present embodiment is executed as described above.

  According to the present embodiment, motoring of the engine 200 using the motor generator MG1 is executed instead of scavenging the exhaust pipe 212 by the electric air pump 500 according to the first and second embodiments, and the first and second embodiments are performed. As with the configuration, scavenging of the exhaust pipe 212 can be performed.

  Further, the motoring of the engine 200 is stopped when the EHC 400 is sufficiently scavenged to prevent leakage during energization, and the newly counted engine stop period Ts is again set to the reference value Tsth (the reference value in this case). The value may be different from the initial reference value because the exhaust gas containing more water than the intake air does not exist in the exhaust pipe 212 due to the initial scavenging. Since the process is resumed, it is possible to reduce the consumption of electric power resources required for motoring as much as possible, which is more efficient. Needless to say, if the motoring is replaced with the start of the electric air pump 500, the same effect can be obtained in the first and second embodiments.

  In the first to third embodiments, the hybrid vehicle 10 is used as an example of the vehicle according to the present invention. However, the vehicle control device according to the present invention is not limited to the hybrid vehicle and is widely used in general vehicles. Is applicable. That is, the EHC scavenging control according to the first and second embodiments can be similarly applied to a vehicle including only the engine 200 as a power source, and even if the EHC scavenging control according to the third embodiment is performed, For example, the present invention can be similarly applied by providing a scavenging rotary electric machine instead of the motor generator MG1 or by using a cranking motor or the like. In any case, the effect that the leakage can be avoided without reducing the effectiveness of the EHC 400 is not changed.

  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. Is also included in the technical scope of the present invention.

  The vehicle control device according to the present invention can be applied to a vehicle including an electrically heated catalyst device.

  DESCRIPTION OF SYMBOLS 10 ... Hybrid vehicle, 100 ... ECU, 200 ... Engine, 202 ... Cylinder, 203 ... Intake pipe, 211 ... Exhaust manifold, 212 ... Exhaust pipe, 217 ... Scavenging passage, 300 ... Power split mechanism, 400 ... EHC, 410 ... Case , 420 ... heat insulating member, 430 ... EHC carrier, 440 ... upstream temperature sensor, 450 ... positive electrode, 470 ... negative electrode, 490 ... downstream temperature sensor, 500 ... electric air pump, 600 ... PCU, 700 ... battery.

Claims (5)

An internal combustion engine;
An electrically heated catalyst device installed in the exhaust passage of the internal combustion engine and generating heat when energized;
An air flow generating means capable of generating an air flow in the exhaust passage;
Acquisition means for acquiring a predetermined determination index value associated with the amount of condensed water generated in the exhaust passage;
Discrimination means for discriminating whether or not the generation amount is equal to or greater than a reference value based on the obtained determination index value;
First control means for controlling the air flow generating means so that the air flow is generated when it is determined that the internal combustion engine is in a stopped state and the generation amount is equal to or greater than the reference value. A control apparatus for a vehicle. 2. The vehicle control device according to claim 1, wherein the air flow generation unit is a motoring device capable of motoring the internal combustion engine or a pump device capable of pressure-feeding air to the exhaust passage. The acquisition means acquires the duration of the stop state as the determination index value,
The vehicle control device according to claim 1, wherein the determination unit determines that the generation amount is equal to or greater than the reference value when the acquired duration exceeds a predetermined value. 4. The apparatus according to claim 1, further comprising second control means for controlling the electric heating catalyst device so that the energization is started before and after the air flow is generated. The vehicle control device according to claim 1. The vehicle is
Rotating electrical machinery,
A difference between the first rotating element connected to the rotating shaft of the rotating electrical machine, the second rotating element connected to the driving shaft connected to the axle, and the third rotating element connected to the rotating shaft of the internal combustion engine. A power transmission mechanism having a plurality of rotational elements capable of dynamic rotation, and a hybrid vehicle,
The vehicle control device according to any one of claims 1 to 4, wherein the first control unit controls the rotating electrical machine as the airflow generation unit.

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