JP2010112191A - Control device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely remove a deposit generated in an EGR passage, in an internal combustion engine having the EGR passage capable of recirculating EGR gas being a part of exhaust gas to an intake flow passage. <P>SOLUTION: This control device 30 of the internal combustion engine 100 has a specifying means 31 for specifying an opening-closing state of an intake valve and an exhaust valve in a cylinder provided in the internal combustion engine, and a control means 32 for controlling a supercharger 23 and an adjusting means 45 so that suction air flows to an exhaust flow passage 41 from an intake flow passage 21 via the EGR passage 43 when the internal combustion engine is stopped and the intake valve and the exhaust valve are put in a predetermined non-overlapping state based on the specified opening-closing state. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is, for example, for scavenging the EGR passage and the exhaust passage in an internal combustion engine having an EGR (Exhaust Gas Recirculation) passage capable of returning EGR gas that is a part of exhaust gas to the intake passage. The present invention relates to a technical field of a control device for an internal combustion engine.

  As this type of device, for example, when the engine is stopped, the EGR passage is opened for a predetermined time and the electric supercharger is driven, and the fresh air supercharged by the electric supercharger is caused to enter the EGR passage. Some gas scavenges gas remaining in the EGR passage (see Patent Document 1). The EGR passage includes a first EGR passage that does not have an EGR cooler and a second EGR passage that has an EGR cooler, and any EGR passage can be scavenged by controlling a valve that opens and closes each EGR passage. It is said that.

  Further, in the EGR non-execution region, the EGR valve is closed, and the on-off valve installed in the return passage that connects the exhaust pipe downstream of the turbine and the EGR passage upstream of the EGR valve is opened, There is one that removes deposits attached to the EGR cooler by introducing a part into the reflux passage and backflowing the section where the EGR cooler is installed (see Patent Document 2).

  Further, for example, a communication passage that connects an EGR passage on the upstream side of the EGR cooler and an intake passage on the upstream side of the compressor is provided, and high pressure air discharged from the compressor is guided to the communication passage when the supercharging pressure is excessive. Therefore, there is also proposed a method for backwashing the EGR cooler (see Patent Document 3).

  Further, for example, in an idle state before the engine stops in a diesel engine, the intake pipe pressure is set higher than the exhaust pipe pressure, and the EGR valve is opened for a predetermined time, whereby the EGR pipe provided with the EGR cooler is washed with intake air. There is a thing (refer patent document 4).

JP 2008-75589 A JP 2006-112320 A Japanese Patent Laid-Open No. 11-62722 JP 2003-206913 A

  In an internal combustion engine having an EGR passage, moisture in the EGR gas (that is, exhaust gas) is cooled and condensed in the EGR passage, and various deposits (that is, deposits such as fuel components or exhaust particulates) are generated. There is. In particular, when a cooling means such as an EGR cooler is provided in the EGR passage, the tendency is remarkable. In addition, this type of deposit is likely to occur remarkably when the internal combustion engine is apt to decrease in engine temperature. At this time, the generated deposit or condensed water, for example, adheres to these cooling means and closes the cooling means or the EGR passage, thereby inhibiting smooth circulation of the EGR gas.

  In order to deal with such a problem, the apparatus described in Patent Document 2 scavenges the EGR passage by exhaust gas (because it is not exhausted to EGR and is simply exhaust gas) during operation of the internal combustion engine. In addition, scavenging itself in the sense that the exhaust is discharged from the EGR passage is impossible. Therefore, the problem that such deposit is generated and adhered from the exhaust gas staying in the EGR passage during the period in which the internal combustion engine is stopped is hardly solved.

  On the other hand, in the apparatus described in Patent Document 3, although intake air is used for scavenging the EGR passage, a condition that the supercharging pressure is excessive is attached, and it is difficult to ensure the frequency of scavenging. Further, since exhaust gas must be used to drive the compressor, it is extremely difficult in practice to perform scavenging of the EGR passage during the stop period of the internal combustion engine. Accordingly, during the stop period of the internal combustion engine, EGR gas stays in the EGR passage with high probability, and it is difficult to solve the problem of deposit generation and adhesion.

  On the other hand, in the devices described in Patent Document 1 and Patent Document 4, scavenging of the EGR passage is performed by fresh air supplied through the intake system while the internal combustion engine is stopped or before the engine is stopped. Therefore, at first glance, it is possible to prevent deposits from adhering to the cooling means.

  However, in some internal combustion engines, particularly those using gasoline as fuel, the valve timing is such that the opening and closing periods of the intake and exhaust valves for each cylinder overlap somewhat (so-called “valve overlap” occurs). There are many that are set. For this reason, as in the devices described in Patent Document 1 and Patent Document 4, in the category of the technical idea of simply scavenging the EGR passage in synchronization with the engine stop timing of the internal combustion engine, the valves that both open and close the intake and exhaust valves When scavenging is performed in the overlap period, a part of the fresh air to be used for scavenging may be discharged through the inside of the cylinder without flowing back through the EGR passage. Thus, when a part of the fresh air to be used for scavenging is discharged without being used for scavenging, the flow pressure of the fresh air flowing back through the EGR passage decreases, and the EGR passage can be sufficiently scavenged. That is, it becomes difficult to avoid generation of deposits in the EGR passage.

  That is, in the conventional techniques including the above examples, the fresh air that should be used for scavenging before and after the internal combustion engine stops cannot be sufficiently guided to the EGR passage. There is a technical problem that it is difficult to reliably avoid deposit formation and adhesion to them.

  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 makes it possible to reliably remove deposits generated in an EGR passage.

  In order to solve the above problems, a control device for an internal combustion engine according to the present invention is mounted on a vehicle and is disposed in an intake passage and configured to be drivable by a predetermined driving means, and has one end An EGR passage connected to the exhaust passage and connected at the other end to the downstream side of the supercharger in the intake passage, and capable of returning EGR gas as a part of the exhaust to the intake passage. A control unit for an internal combustion engine having an adjustment unit capable of adjusting a flow rate of the EGR gas in the EGR passage, wherein the specifying unit specifies an open / close state of an intake valve and an exhaust valve in each of the cylinders of the internal combustion engine And when the internal combustion engine is stopped and the intake valve and the exhaust valve are in a predetermined non-overlap state based on the specified open / closed state, It said to flow the intake air into the air flow path and a control means for controlling the supercharger and the adjusting means.

  An “internal combustion engine” according to the present invention is a system or a device group that is mounted on a vehicle and can convert combustion of fuel generated inside a cylinder into mechanical power that can be a driving force of the vehicle. In addition, the individual specific configuration is not intended to be limited within the scope of the concept, but as a preferred embodiment, for example, a fuel injection device mainly related to combustion of fuel and generation of mechanical power associated therewith, An ignition device, an intake / exhaust valve, a drive system of the intake / exhaust valve, a main body that can appropriately include a cylinder, a piston, a rotor, a connecting rod, a crankshaft, and the like, and an intake that is appropriately connected to the main body and sucked from the outside An intake system for supplying air to the main body and an exhaust system for discharging the burned or partially unburned or incompletely burned gas discharged from the main body to the outside Et al constructed.

  In the internal combustion engine according to the present invention, an intake flow path (that is, preferably a part of the intake system described above, which may include an intake pipe, an intake manifold, etc.), which is a flow path of intake air, A supercharger that enables supercharging of intake air, for example, a fluid compression means such as a compressor, can be provided. This supercharger can appropriately include, for example, various motors such as a motor or a drive device that can drive the motor in addition to the motor, and at least the supercharging action regardless of whether the internal combustion engine is in operation or not. It is configured to be able to be driven at a desired timing by various driving means configured to be able to generate (pumping action of intake air). For example, when the supercharger adopts a configuration that generates a supercharging action by rotation of the rotary shaft, the drive means has a configuration that can apply a driving force to rotate the rotary shaft at a desired timing. You may do it. In addition, as long as appropriate driving is possible by the driving means, the supercharger is limited only when an internal combustion engine such as an exhaust driving turbine is operating (in this case, only when an exhaust flow exists). ) A means for contributing to supercharging may be provided. In this case, the supercharger may be configured as a so-called MAT (Motor Assist Turbo) that assists the rotation of the turbine or the compressor by the motor.

  In addition, the internal combustion engine according to the present invention provides an exhaust gas from an exhaust gas channel (that is, preferably a part of the above-described exhaust system, and may include an exhaust pipe, an exhaust manifold, etc.). Is provided with an EGR passage capable of returning a part of the gas as EGR gas to the intake passage. The EGR passage may have a configuration in which a plurality of passage portions are integrally formed with each other, and a plurality of independent pipe lines are connected to each other regardless of whether they are directly or indirectly, and are externally connected. It may have a configuration that can be regarded as an upper unit, and at least one end thereof is connected to the exhaust passage and the other end is connected to the intake passage. The pressure of the exhaust passage (ie, the exhaust pressure) is usually higher than the pressure of the intake passage (ie, the intake pressure) during operation of the internal combustion engine (of course, depending on the supercharging pressure of the supercharger) EGR gas recirculates in the EGR passage in accordance with, for example, the pressure difference between them.

  Furthermore, the internal combustion engine according to the present invention is configured to change the flow rate of EGR gas in the EGR passage (hereinafter referred to as the EGR passage or the intake passage, for example, by changing the communication area between the intake passage and the exhaust passage). (It is abbreviated as “EGR amount”) as appropriate (in the present invention, “adjustment” means binary according to some intentions, stepwise with a constant or indefinite step width, or continuous (practical) Adjustment that can take the form of a valve device such as an EGR valve having a valve body that can be opened and closed in the EGR passage. Means are provided. Even if the EGR passage is constructed to recirculate the EGR gas as a main purpose, the control of the adjusted element in the adjusting means accompanying the change in the EGR amount (for example, the control of the opening degree of the valve body, etc.) However, it goes without saying that the flow rate of the fluid (for example, intake air for scavenging described later) that can flow through the EGR passage is affected not only by the EGR gas.

  According to the control device for an internal combustion engine according to the present invention, the control means that can take the form of various processing devices such as an ECU (Electronic Control Unit), various computer systems such as various controllers or a microcomputer device, and the like. When the internal combustion engine is stopped (stopped) based on the open / close state of the intake / exhaust valves specified for each cylinder of the internal combustion engine by specific means that can take the form of various computer systems such as a processing device, various controllers or microcomputer devices The intake air flows from the intake flow path to the exhaust flow path via the EGR passage when the intake valve and the exhaust valve are in a non-overlapping state at the time point. To control the supercharger and the adjusting means (for this supercharger and adjusting means) The control performed in this way is hereinafter referred to as “scavenging control” as appropriate).

  “Non-overlapping state” means “not in an overlapping state”, and the overlapping state means a state in which both the intake valve and the exhaust valve are open in one cylinder. means. That is, the “non-overlap state” is equivalent to a state in which at least one of the intake valve and the exhaust valve is closed in one cylinder.

  Here, when the internal combustion engine is stopped, the intake and exhaust valves are not constantly opened and closed, and natural intake (natural intake of air due to negative pressure) does not occur, and the EGR passage is closed (intake). In view of the fact that the gas flow in the EGR passage stops when the communication between the flow path and the exhaust flow path is interrupted), the scavenging control performed by the control means is simply driven The supercharger is operated via the means and at least a part of the EGR passage is opened (regardless of the degree of opening) via the adjusting means (maintaining the state when already opened) Control). When the scavenging control is executed, the EGR gas remaining in the EGR passage can be considerably sucked at least from the outside regardless of the set supercharging pressure of the supercharger and can be guided from the intake passage to the exhaust passage. The intake air is discharged from the EGR passage, and scavenging of the EGR passage is realized.

  Here, in particular, when the scavenging control is executed, the intake and exhaust valves are in a non-overlapping state, so that the intake air guided to the intake flow path by the supercharging action of the supercharger passes at least inside the cylinder. However, substantially the entire amount is discharged to the exhaust passage through the EGR passage. Therefore, the intake air contributing to the scavenging of the staying EGR gas has a flow rate as high as possible, and the flow pressure is maintained as high as possible. As a result, the scavenging effect of the EGR gas staying in the EGR passage is clearly greater than when the intake and exhaust valves are in the overlap state.

  That is, according to the control apparatus for an internal combustion engine according to the present invention, the EGR gas remaining in the EGR passage is caused by condensation of moisture in the process of natural cooling over time, for example, during the stop period of the internal combustion engine. The generation of deposits is preferably avoided, and the deposits adhere to the inside of the EGR passage, and the concern that the EGR (reduction of NOx due to exhaust gas recirculation) will be adversely affected is eliminated. In particular, the EGR passage is often provided with various cooling means for cooling EGR gas, such as an EGR cooler, regardless of whether it is air-cooled or water-cooled. In such a configuration, the internal combustion engine is in a stop period. Even if this type of deposit is not easily generated, the generated deposit is likely to adhere to these cooling means, so that the scavenging control effect according to the present invention is great.

  In particular, in an internal combustion engine using gasoline as fuel, the valve timing of the intake and exhaust valves (that is, the timing of opening and closing, which is set in association with the crank angle, for example) is basically a part of the operation stroke. In many cases (for example, at the end of the exhaust stroke or the initial stage of the intake stroke), the intake and exhaust valves are often set to be in an overlapped state. Therefore, if this type of scavenging is performed without paying any attention to whether the intake and exhaust valves are in an overlapped state, appropriate energy resources are consumed when the internal combustion engine is stopped (ie, the operation of the internal combustion engine is not performed). (It is difficult to use the energy of the exhaust unlike at times.) The intake air for scavenging that has been taken in at an angle is discharged with a high probability to the exhaust passage without passing through the EGR passage. Therefore, there is a high possibility that the scavenging effect is reduced, for example, the flow rate of the intake air contributing to scavenging is reduced and the flow pressure is also reduced. That is, it can be said that the present invention is clearly superior in that the EGR passage can be surely scavenged and the generation and adhesion of deposits can be reliably avoided as compared with scavenging performed in the category of this kind of technical idea.

  The “open / closed state” specified by the specifying means includes at least a binary state indicating whether the valve is open or closed. As a preferred embodiment, for example, a valve opening degree (degree of valve opening) A multivalued state can be taken. Here, “specific” according to the present invention is a concept that encompasses detection, estimation, calculation, derivation, identification, and acquisition, and the like. The process is intended to have various aspects as long as the control means can finally grasp the information that can be referred to for control.

  For example, when the relationship between the cam position (also referred to as cam rotation angle or cam phase) of each of the intake cam and exhaust cam and the valve position is known, these cam positions (for example, from a sensor capable of detecting the cam position) The opening / closing state may be specified based on the crank angle if the relationship between the cam position and the crank angle is known. Further, for example, the open / closed state may be specified based on the valve timing of the intake / exhaust valve, whether it is a fixed value or a variable value. Or, if the vehicle is equipped with means that can change the cam position or valve position of the intake / exhaust valve such as cam-by-wire or electric drive valve device by the electric or magnetic driving force supplied from various actuators, etc. The open / close state of the intake / exhaust valve may be specified based on the operating state of the actuator.

  Note that the non-overlap state of the intake / exhaust valve is, for example, (1) when the non-overlap state cannot be generated from the valve timing of the intake / exhaust valve at that time. It can always occur at any point of time when the engine stops, and (2) even if the valve timing is set so that the intake and exhaust valves can be in an overlapped state in some operating strokes as described above (3) Even when the intake and exhaust valves are stopped in an overlapped state in some cylinders when the internal combustion engine is stopped, an appropriate drive target (for example, a valve, a cam, a camshaft, or There are a variety of processes leading to the manifestation, such as driving the intake / exhaust valve by applying driving force to the crankshaft etc.). Engine is stopped and the intake and exhaust valves as long as the scavenging control is made when in the non-overlapping state, deposit generation and deposition in the exhaust passage communicating with the EGR passage or it is suitably avoided.

  In the present invention, the control means performs the scavenging control when the internal combustion engine is stopped and the intake / exhaust valve is in the non-overlapping state, but the start timing at which the execution of the scavenging control is started is It may be included in a transition period (for example, a period until the engine motion of the internal combustion engine is physically stopped due to friction or the like from the time when the stop request is generated) or the intake / exhaust state. It may be included in the period when the valve is still in the overlap state. That is, as long as the period in which the internal combustion engine is stopped and the intake / exhaust valve is in the non-overlap state is included as at least part of the execution period of the scavenging control, the above-described operational effects according to the present invention are ensured. The start timing of the scavenging control itself does not need to be restricted by the open / close state of the intake / exhaust valve and the operating state of the internal combustion engine.

  In one aspect of the control apparatus for an internal combustion engine of the present invention, the control means controls the adjusting means so that the flow rate of the intake air flowing through the EGR passage is maximized.

  According to this aspect, for example, when the adjusting means is an EGR valve or the like, the intake air for scavenging introduced into the EGR passage by the supercharging action of the supercharger is caused by fully opening the EGR valve or the like. Since the flow rate at the time of flowing through the passage becomes maximum at least under the condition that the supercharging pressure is constant, the scavenging effect in the EGR passage is great, which is preferable. In addition, in addition, in this case, the flow rate of the scavenging intake air is within a range that can be provided by the adjusting means by, for example, maximizing the communication area between the intake flow path and the exhaust flow path via the EGR passage. It is not necessarily “maximum” within the range of theoretical or practical constraints due to the cooperative control of the turbocharger and the adjusting means. That is, depending on the control mode of the driving means, it is not impossible to obtain a flow rate larger than the “maximum” flow rate defined herein. However, the amount of energy resources required to drive the driving means and the amount of energy resources required to drive the adjusting means are often smaller in the latter, and therefore, as much as possible within the range that can be achieved by the adjusting means. In view of the effect and efficient use of energy resources, it can be one of the best measures in practice.

  In another aspect of the control device for an internal combustion engine of the present invention, the vehicle further includes an open / close state variable means capable of changing the open / close state, and the control means is configured to stop the internal combustion engine when the internal combustion engine is stopped. Before and after the control of the supercharger and the adjusting means, the open / close state variable means is controlled so that the intake valve and the exhaust valve are in the non-overlapping state.

  According to this aspect, when the internal combustion engine is stopped, immediately before or after the execution of the scavenging control described above, for example, directly or indirectly via the intake / exhaust cam or the like with respect to the intake valve and / or the exhaust valve. The intake / exhaust valves can be brought into a non-overlapping state through the control of an open / close state variable means such as VVT (Variable Valve Timing) which can change the open / close state by applying a driving force or the like. The Therefore, regardless of the original valve timing and the open / close state of the intake / exhaust valve immediately after the engine stops, the scavenging control can be executed reliably, and the scavenging control execution frequency can be increased. It is possible and useful in practice.

  For example, during cranking of an internal combustion engine, rotation of the crankshaft is preferably performed by rotation of intake and exhaust camshafts connected to the crankshaft via a transmission means such as a timing chain or a timing belt. Is converted to Further, the rotation of these cam shafts corresponds to the rotation of the corresponding cam and is finally converted into an opening / closing operation of the intake / exhaust valve. Therefore, the open / close state varying means may include, for example, a cranking motor or a driving system in addition to the cranking motor.

  Further, a hybrid vehicle having a motor generator or the like as a power source in addition to the internal combustion engine includes a plurality of motor generators, and the engine output shaft (for example, a crankshaft) of the internal combustion engine is, for example, mutually differential. It is connected to one rotating element of a power split mechanism configured as a planetary gear mechanism or the like having a plurality of rotatable rotating elements, and these motor generators are connected to other rotating elements to Some have a hybrid drive device of a type that supplies power to the axle by cooperative control with a generator. In this case, one of the motor generators can have a function equivalent to the above-described cranking motor, and more precisely, it can also function as a rotation control device that controls the engine rotation speed of the internal combustion engine. For example, prior to the execution of the scavenging control, a non-overlapping state is realized by rotating the crankshaft by a necessary angle so that the intake valve and the exhaust valve are in a non-overlapping state for all cylinders. Can be made simple and possible. That is, in some cases, this type of motor generator can also be the open / close state varying means according to the present aspect.

  In another aspect of the control device for an internal combustion engine of the present invention, the control means is configured such that the intake valve and the exhaust valve for the respective non-overloads in response to a stop request indicating that the internal combustion engine should be stopped. The internal combustion engine is stopped so as to stop in a lap state.

  According to this aspect, the control means performs intake / exhaust for each cylinder when a stop request for stopping the internal combustion engine is generated, for example, when the ignition is turned off or when the power source is requested to be switched (in the case of a hybrid vehicle). The internal combustion engine is stopped so that the valve stops in a non-overlapping state. For this reason, when the internal combustion engine is stopped, the non-overlap of the intake / exhaust valves is more efficiently performed than when the corresponding energy resources are consumed by, for example, driving control of the opening / closing state varying means described above. The state can be obtained. This is because there is a time delay due to inertial drive from the time when the throttle valve and fuel are controlled until the actual stop, and no active energy consumption occurs during such inertial drive. That is, for example, the fuel injection device and the throttle valve are set based on, for example, experimentally, empirically, theoretically, or simulation in advance according to the engine rotational speed (which defines the magnitude of inertia). VVT, cranking motor, motor generator, etc. by consuming appropriate energy resources after the internal combustion engine stops by controlling according to the driving conditions etc. that the intake and exhaust valves stop in a non-overlapping state This makes it possible to obtain a non-overlapping state of the intake and exhaust valves more efficiently than obtaining the same kind of state.

  In a configuration in which a driving force can be applied to the crankshaft, such as a cranking motor or a motor generator, when the internal combustion engine is stopped, an appropriate driving force is applied to the crankshaft to stop the intake and exhaust valves in a non-overlapping state. Can also be given. In this case, as compared with driving the internal combustion engine from a completely stopped state, the driving force may be reduced by the amount of inertial force. That is, in such a case, the control object of the control means according to this aspect may be a cranking motor or a motor generator. More specifically, for example, as a result of applying a driving force from these cranking motor, motor generator, or the like in response to a stop request, the rotational speed of the crankshaft is temporarily decelerated. Along with this, the temporarily decelerated rotation of the crankshaft acts on the camshaft via a timing gear or the like, and the rotation phase of the corresponding cam is controlled. Thereby, when the internal combustion engine is stopped, for example, the intake valve and the exhaust valve that should be stopped in the overlap state at the original valve timing can be stopped in the non-overlap state.

  Note that the “stop request” according to this aspect is not limited to a request that is artificially generated through a predetermined operation means such as the above-mentioned ignition off, but without any manual operation when some condition is satisfied. In other words, it may occur automatically. For example, in the hybrid vehicle described above, it may be possible to run using only a power source other than an internal combustion engine such as a motor, and various vehicles such as vehicle speed, required output, required load or required driving force may be used. Depending on the driving conditions, this type of traveling mode may be switched as appropriate. In such a case, a stop request for stopping the internal combustion engine is automatically generated by various control devices (which may be “control means” according to the present invention), a controller, or the like, without any manual operation. obtain.

  In another aspect of the control device for an internal combustion engine of the present invention, the vehicle is a hybrid vehicle that functions as a power source together with the internal combustion engine and includes at least one electric motor that is driven by power supply via a power storage unit. is there.

  In this type of hybrid vehicle, the vehicle can be driven only by the power of an electric motor (or a motor generator such as a motor generator having a power generation function), and the operating frequency of the internal combustion engine is limited to that of the internal combustion engine. Compared to a vehicle having a power source, it tends to decrease. Even when the vehicle is driven by cooperative control of the internal combustion engine and the electric motor as part of the power to be supplied to the axle without traveling by only the power of the electric motor, the internal combustion engine has its temperature. The rise may be slow. Therefore, in this type of hybrid vehicle, the engine temperature of the internal combustion engine is likely to decrease, and the above-described problems such as deposit generation and adhesion in the EGR passage are likely to become obvious. That is, the control device for an internal combustion engine according to the present invention can exert its effect remarkably when applied to this type of hybrid vehicle.

  In addition, the power storage means may include an external power source (for example, a home-installed or portable power source (for example, a home outlet and a dedicated or general-purpose charging plug as appropriate), or Installed in an urban area or suburban area as a dedicated or general-purpose infrastructure facility (meaning various power sources that may be attached to, for example, a gas station or a similar infrastructure facility) When the hybrid vehicle is configured as a so-called plug-in hybrid vehicle that is configured to be rechargeable by power supply, for example, a travel mode in which the main power source of the vehicle is an electric motor and EV (electric vehicle) travel is maintained as much as possible. May be selected. In such a case, since the operating frequency of the internal combustion engine can be significantly reduced, the present invention can operate more effectively.

  For example, when the driving means for driving the supercharger uses a power storage means such as a hybrid battery as a power source, the scavenging control by the control means is performed in consideration of the SOC (State Of Charge) of the power storage means. May be.

  In another aspect of the control apparatus for an internal combustion engine of the present invention, the drive means includes an electric motor.

  According to this aspect, it is possible to simply drive the supercharger at a desired timing.

  The effect | action and other gain of this invention are clarified from embodiment described below.

<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 a hybrid vehicle 200 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram conceptually showing the configuration of the hybrid vehicle 200.

  In FIG. 1, a hybrid vehicle 200 includes an engine 100, a power split mechanism 11, a drive wheel 12, a generator 13, an inverter 14, a battery 15, a motor 16, and a speed reduction mechanism 17 as a power system, and an ECU 30 as a control system. 1 is an example of a “hybrid vehicle” according to the present invention.

  The power split mechanism 11 is a planetary gear mechanism configured to be able to distribute engine torque as output power of the engine 100 to the generator 13 and the speed reduction mechanism 17. The power split mechanism 11 is arranged between a sun gear provided in the center, a ring gear provided concentrically on the outer periphery of the sun gear, and the sun gear and the ring gear, and revolves while revolving around the outer periphery of the sun gear. And a planetary carrier that is coupled to the end of the crankshaft of the engine 100 and supports the rotation shaft of each pinion gear.

  The sun gear is coupled to the rotor of the generator 13 via the sun gear shaft, and the ring gear is coupled to the rotor of the motor 16 via the ring gear shaft. The ring gear shaft is connected to the drive wheel 12 which is the drive wheel of the hybrid vehicle 200 via the speed reduction mechanism 17 and the axle, and the output power of the motor 16 is driven to the drive wheel via the ring gear shaft, the speed reduction mechanism 17 and the axle. Similarly, the driving force from the driving wheel 12 is input to the motor 16 via the axle, the speed reduction mechanism 17 and the ring gear shaft. Under such a configuration, the power split mechanism 11 causes the engine torque to be transmitted to the sun gear and the ring gear by the planetary carrier and the pinion gear, and is divided into two systems. Note that the configuration of the power split mechanism is not limited to that of the power split mechanism 11 illustrated here, and may adopt various known aspects.

  The generator 13 is configured to function as a generator for charging the battery 15 or supplying electric power to the motor 16 and further as an electric motor for assisting the power of the engine 100 according to the present invention. This is a motor generator as an example of an “electric motor”. As described above, the generator 13 has a rotor connected to the sun gear of the power split mechanism 11 and rotates according to the gear ratio between the sun gear and the planetary carrier when the crankshaft of the engine 100 rotates. It has become. In addition, the generator 13 normally functions as a reaction force element that bears the reaction torque of the engine torque of the engine 100, and exhibits a power generation action by outputting a reaction torque that is a negative torque, for example, in a positive rotation region. On the other hand, the generator 13 can of course rotate independently, and the output torque from the generator 13 is transmitted to the crankshaft of the engine 100 via the sun gear and the planetary carrier. It is also possible to control freely. Therefore, the generator 13 can also function as cranking means for performing cranking when the engine 100 is started.

  The inverter 14 inputs and outputs power between the battery 15 and the generator 13 and the motor 16 or inputs and outputs power between the generator 13 and the motor 16 (that is, without using the battery 15 in this case). This is a constituent element of a PCU (Power Control Unit) (not shown) that controls power transmission / reception between the generator and the motor, and an alternating current supplied from the generator 13 or the motor 16 is converted into a direct current. The converter 15 is configured to charge the battery 15 and to convert the DC power extracted from the battery 15 into AC power and supply it to the generator 13 or the motor 16. The PCU is electrically connected to the ECU 30 and its operation is controlled by the ECU 30. That is, the operating state of the inverter 14 is also controlled by the ECU 30.

  The battery 15 is a rechargeable storage battery configured to be able to function as a power supply source for powering the generator 13 and the motor 16, and is an example of the “storage unit” according to the present invention.

  The motor 16 is configured to function as an electric motor that is one power source of the hybrid vehicle 200 and further as a generator for charging the battery 15, and is a motor generator that is another example of the “electric motor” according to the present invention. It is. As described above, the motor 16 has a rotor connected to the ring gear of the power split mechanism 11 and can directly output power (torque) to the speed reduction mechanism 17. For example, the motor 16 is supplied with power from the generator 13 or the battery 15 or the generator 13 and the battery 15 and compensates for the shortage of the engine torque via the power split mechanism 11 with respect to the required torque to be output to the axle. Therefore, the driving state is controlled by the ECU 30. In addition, when the motor 16 is rotated by torque input from the drive wheels 12 via the axle, such as when the hybrid vehicle 200 is decelerated (that is, negative torque), the motor 16 operates in the positive rotation negative torque region. And has a power generation effect. That is, in this case, so-called power regeneration is performed.

  The generator 13 and the motor 16 according to the present embodiment are configured as a synchronous motor generator, and a stator 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. However, other types of motor generators may be used.

  The engine 100 is an in-line four-cylinder gasoline engine that functions as a power source of the hybrid vehicle 200 together with the motor 16 and is an example of the “internal combustion engine” according to the present invention. A detailed configuration of the engine 100 will be described later with reference to FIG.

  The ECU 30 includes a CPU, a ROM, a RAM, an A / D converter, and the like, and is configured to be capable of comprehensively controlling each part of the engine 100. It is an electronic controller which is an example. The detailed configuration of the ECU 30 will be described later with reference to FIG.

  Here, with reference to FIG. 2, the detailed structure of the engine 100 and ECU30 is demonstrated. FIG. 2 is a schematic configuration diagram conceptually showing the configurations of the engine 100 and the ECU 30. 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.

  In FIG. 2, the engine 100 includes a main body 10, an intake system 20, and an exhaust system 40.

  The main body 10 includes (1) a crankshaft that is an engine output shaft of the engine 100, (2) a piston that is arranged in series in the horizontal direction of the paper surface, and that is configured to be capable of reciprocating in the depth direction of the paper surface inside each Four cylinders provided with a connecting rod or the like capable of converting the reciprocating motion of the piston into the rotational motion of the crankshaft; (3) an intake cam shaft and an exhaust camshaft that rotate in synchronization with the rotation of the crankshaft; Intake air and exhaust cam fixed to the intake cam shaft and the exhaust cam shaft, intake side rocker arm and exhaust side rocker arm that can be swung by the intake cam and exhaust cam, intake air driven by the intake side rocker arm and exhaust side rocker arm, respectively. By rotating the intake cam shaft relative to the valve, exhaust valve, and crankshaft, the cam position of the intake cam (cam rotation angle or A valve system (not shown) including a known vane-type intake-side VVT controller, a fuel tank, and various fuels for supplying gasoline as fuel from the fuel tank. A fuel system including a supply passage and an injector or the like capable of injecting fuel supplied through these various fuel supply passages into an intake port; an ignition system including an ignition device partially exposed in the combustion chamber; and an intake system The cooling water circulation supply path including an intake port for communicating the cylinder 20 with the inside of the cylinder, an exhaust port for communicating the exhaust system 40 with the cylinder interior, a water jacket stretched around the outer periphery of the cylinder, and the cooling water circulation supply path And a cooling system configured to cool the engine 100 (all not shown).

  The operation of the main body 10 causes the combustion of fuel (air-fuel mixture containing fuel) in the combustion chamber of each cylinder, and as a result, the crankshaft as the engine output shaft rotates. The rotation of the crankshaft is transmitted to the drive wheels 12 via the power split mechanism 11 and the speed reduction mechanism 17 as described above.

  The intake system 20 includes an intake flow path 21 that is a flow path of intake air sucked from the outside. Further, in the intake flow path 21, from the upstream side, an air cleaner 22, an electric turbo 23, an intercooler (that is, in FIG. 2). , Indicated as “I / C”) 24, a throttle 25 and an intake manifold 26.

  The air cleaner 22 is an outside air purification device configured to be able to filter intake air drawn from the outside.

  The electric turbo 23 is an example of a “supercharger” according to the present invention, which includes a motor, a turbine, and a compressor (not shown).

  In the electric turbo 23, the compressor is a compressor configured to be able to compress the intake air guided to the intake passage 21 by the rotation of the rotary shaft and pump the compressed air to the downstream side. In the present embodiment, the “supercharger” according to the present invention strictly means this compressor. On the other hand, the turbine is installed in an exhaust passage 28 described later, and is driven to rotate by the pressure of the exhaust gas flowing through the exhaust passage 28. The rotating shaft of the turbine is connected to the rotating shaft of the compressor, and when the turbine is rotationally driven by exhaust, the compressor is also rotationally driven.

  On the other hand, the motor is a DC brushless motor configured to be driven by a power supply from the battery 15 via a drive system (not shown). The motor shaft connected to the rotor of this motor is disposed coaxially with the rotating shafts of the previous turbine and compressor, and is fixed to be rotatable integrally with the rotating shafts of this turbine and compressor. Therefore, the electric turbo 23 can rotate the compressor by the driving force from the motor even when the engine 100 is in a stopped state and there is no exhaust flow. The intake air can be supercharged regardless of the state. That is, the motor and its drive system are examples of the “drive means” according to the present invention. Note that this drive system is electrically connected to the ECU 30, and the drive state is controlled by higher-level control from the ECU 30.

  The intercooler 24 has a heat exchange wall inside thereof, and when the intake air pressurized by the electric turbo 23 passes, the intake air is exchanged by heat exchange generated between the intake air and the heat exchange wall. The cooling device is configured to be cooled.

  The throttle 25 has a valve body that is opened and closed in conjunction with the accelerator operation by the driver, and is configured to be able to adjust the amount of intake air supplied to the main body 10 in accordance with the open / closed state of the valve body. Electronically controlled valve device.

  The intake manifold 26 is a tubular member that connects the intake passage 21 and an intake port that communicates with each cylinder. The shape of the intake manifold 26 is configured so that intake air as homogeneous as possible (for example, the phases of intake pulsations are aligned) is sucked into each cylinder.

  The exhaust system 40 includes an exhaust passage 41, an exhaust manifold 42, an EGR passage 43, an EGR cooler 44, and an EGR valve 45.

  The exhaust passage 41 is a tubular member that exhausts the exhaust guided through the exhaust manifold 42 to the outside. Although not shown, the exhaust passage 41 is connected to an exhaust purification device including various catalysts for purifying exhaust, such as a three-way catalyst and an NSR catalyst. After passing through such an exhaust purification device, it is discharged to the outside.

  The exhaust manifold 42 is a tubular member that connects the exhaust passage 41 and the exhaust port (not shown) provided in the main body 10 corresponding to each cylinder.

The EGR passage 43 is a tubular member having one end connected to the exhaust passage 41 in the vicinity of the connection portion with the exhaust manifold 42 and the other end connected to the intake manifold 26. The EGR passage 43 has a configuration in which part of the exhaust gas is appropriately returned to the intake manifold 26 as EGR gas (this direction is assumed to be the forward direction). At this time, the inert CO contained in the EGR gas is used. ₂ lowers the combustion temperature in the combustion chamber and reduces NOx.

  The EGR cooler 44 includes an evaporator (not shown), and is a cooling device configured to be able to cool high-temperature EGR gas immediately after exhaust flowing through the EGR passage 43. In the EGR cooler 44, the evaporator has a filter for filtering the fine particles contained in the EGR gas. When the EGR gas passes through the filter continuously, the exhaust particles are trapped in the filter. Is done. On the other hand, in the EGR passage 43, mainly in the vicinity of the EGR cooler 44, the EGR gas is cooled, so that condensed water is easily generated, and the exhaust particulates and the condensed water generate deposits in the entire EGR passage 43. It is easy to do. This generated deposit adheres to the EGR passage 43 and may become an obstacle when the EGR is performed later. In addition, the structure of an EGR cooler is not limited to the above-mentioned thing. For example, the EGR cooler may share a cooling system included in the main body 10 and a cooling water circulation supply path, and may have a so-called water cooling type cooling mode in which the EGR gas is cooled by heat exchange with the cooling water. Even in this type of EGR cooler, the generation of condensed water due to cooling occurs without any change, and thus the problem of deposit generation and adhesion still occurs.

  The EGR valve 45 is an example of the “flow rate adjusting unit” according to the present invention configured to be able to continuously change the gas amount in the EGR passage 43. The EGR valve 45 is an electromagnetic control valve, and has a configuration in which the valve body seamlessly opens and closes by a driving force from a solenoid that is driven and controlled by the ECU 30. As the valve body is opened and closed, the flow passage cross-sectional area of the EGR passage 43 (the communication area between the intake flow passage and the exhaust flow passage) becomes variable, and the amount of gas flowing through the EGR passage 43 changes continuously.

  The hybrid vehicle 200 is equipped with various sensors (not shown) that are necessary for controlling the operation of the engine 100. For example, in the cooling water circulation supply path in the cooling system of the main body 10 described above, a water temperature sensor capable of detecting the cooling water temperature Tw which is the temperature of the cooling water is disposed. Further, the battery 15 is provided with an SOC sensor, and the SOC of the battery 15 is detected as a standardized detected storage amount SOC1 in which the fully charged state is 100 and the fully discharged state is 0. Yes. Further, a crank angle sensor capable of detecting a crank angle that is a rotation angle of the crankshaft is disposed in the vicinity of the crankshaft included in the main body 10. Further, a cam rotation angle sensor capable of detecting the rotation angles of the intake and exhaust cams is installed in the vicinity of the intake cam and the exhaust cam in the main body 10. Each of these sensors is electrically connected to the ECU 30, and the detection result in each sensor is referred to by the ECU 30 at a constant or indefinite period.

  The valve state detection unit 31 is configured to be able to estimate the open / closed states of the intake valve and the exhaust valve based on the valve timings of the intake valve and the exhaust valve of the engine 100 at that time. It is a sub-processor as an example of “specifying means”. More specifically, the valve state detection unit 31 estimates the opening degree of the exhaust valve based on the reference valve timing (stored as a fixed value in the ROM) and the current crank angle. . As for the intake valve, the current valve value defined by the amount of displacement from the reference position of the intake cam by the intake side VVT controller (that is, the amount of displacement from the reference value of the valve timing of the intake valve) and the reference value of the valve timing. The opening degree is estimated based on the timing and the current crank angle.

  The scavenging control unit 32 is a sub-processor as an example of the “control unit” according to the present invention configured to be able to execute a first scavenging control process with operation control of each part of the engine 100 according to a predetermined control program. It is. Note that the configuration of the ECU 30 illustrated here is merely an example.

<Operation of Embodiment>
Here, with reference to FIG. 3, the detail of the 1st scavenging control process performed by the scavenging control part 32 is demonstrated. FIG. 3 is a flowchart of the first scavenging control process.

  In FIG. 3, the scavenging control unit 32 determines whether or not the engine 100 is in a stopped state (step S51). Here, the “stop state” according to the present embodiment is not a stop state having a substantial meaning that generation of power accompanying fuel combustion is stopped, but the reciprocating motion of the piston is physically stopped. It is a stop state in the sense of being. The scavenging control unit 32 performs the stop determination based on the time displacement amount of the crank angle detected by the crank angle sensor.

  In hybrid vehicle 200, there are mainly two types of cases where engine 100 is in this kind of stop state. That is, one is a case where an operation for stopping the operation of the entire vehicle is performed in advance, such as an ignition off operation, as in other vehicles having only an engine as a power source. This is a case where at least the condition for maintaining the engine in the operating state is changed to the condition for stopping the operation of the engine and selecting EV traveling using only the motor 16. In the latter case, since the operation of the generator 13 is also stopped, the engine 100 loses power against engine friction and stops at an engine speed of zero, but the vehicle itself supplies torque from the motor 16. It is possible to run by. At this time, the generator 13 idles at a rotation speed corresponding to the rotation speed of the motor 16 (that is, the rotation speed of the sun gear, which is the remaining one rotation element, depends on the rotation speed of the ring gear and the rotation speed of the planetary carrier). Unambiguously determined). The engine stop state according to step S51 may be any of these.

  As a result of this determination, when it is determined that the engine 100 is not stopped (step S51: NO), the first scavenging control process ends. Note that the first scavenging control process is a process that is repeatedly executed by the scavenging control unit 32 through a constant or indefinite interval unless the ECU 30 performs a higher-level control prohibiting execution from the CPU.

  On the other hand, as a result of the determination in step S51, when it is determined that the engine 100 is in a stopped state (step S51: YES), the scavenging control unit 32 determines that the detected storage amount SOC1 detected by the SOC sensor is the reference value SOC0. It is determined whether it is larger than (step S52). Note that the reference value SOC0 is a hybrid in which the battery 15 is used for execution of scavenging processing including cam position adjustment, which will be described later, and driving of the EGR valve 45 and the electric turbo 23, which is performed by taking out electric power from the battery 15. The value is experimentally determined in advance as a large value that does not affect the driving of other electrical accessories of the automobile 200. When it is determined that the detected storage amount SOC1 is equal to or less than the reference value SOC0 (step S52: NO), the scavenging control unit 32 determines that the execution of the scavenging process should be avoided and ends the first scavenging control process. To do.

  On the other hand, as a result of the determination in step S52, when it is determined that the detected storage amount SOC1 is greater than the reference value SOC0 (step S52: YES), the scavenging control unit 32 performs the intake valve and the exhaust estimated by the valve state detection unit 31. Based on the opening of the valve, it is determined whether or not the intake / exhaust valve is in an overlapped state (step S53). Here, the overlap state refers to a state where both the intake valve and the exhaust valve are open.

  When it is determined in step S53 that the intake valve and the exhaust valve are in a non-overlapping state (that is, in a state where there is no overlap state and at least one of the intake and exhaust valves is closed) (Step S53: NO), the process proceeds to step S55. On the other hand, when the intake valve and the exhaust valve are in the overlap state (step S53: YES), the scavenging control unit 32 adjusts the position of the intake cam that drives the intake valve in the overlap state under the control of the intake side VVT controller. Execute (Step S54).

  In adjusting the position of the intake cam according to step S54, first, the rotation angle of the intake cam necessary for obtaining a non-overlapping state is calculated. Subsequently, with reference to the output signal of the cam rotation angle sensor, the intake side VVT controller is driven and controlled so that the required rotation angle is obtained.

  Here, supplementarily, the intake side VVT controller has a vane portion attached to the tip end portion of the intake camshaft and a hydraulic drive system including an OCV (Oil Control Valve). The vane portion is fixed to a timing gear connected to the crankshaft through a timing chain, and is fixed to the housing rotating in synchronization with the crankshaft while maintaining a constant phase, and fixed to the intake camshaft, and rotates within the housing. And a vane supported in a possible manner. In the housing, a hydraulic chamber is formed which is a storage chamber for hydraulic oil supplied via a hydraulic drive system, and the vane is rotatable in the hydraulic chamber, and the hydraulic chamber is moved to the advance side. It is divided into a hydraulic chamber and a retarded-side hydraulic chamber. Here, when hydraulic fluid is supplied to the advance side hydraulic chamber or the retard side hydraulic chamber by the position control of the OCV spool valve, the vane has a pressure relationship between the advance side hydraulic chamber and the retard side hydraulic chamber. Accordingly, the inside of the housing is rotated, and accordingly, the intake cam shaft and the intake cam fixed to the intake cam shaft rotate relative to the housing. Since the housing rotates integrally with the crankshaft as described above, the vane position control eventually causes a phase difference between the intake cam and the crankshaft, and the valve timing of the intake cam is made variable. is there.

  In step S54, the scavenging control unit 32 controls the intake and exhaust valves to be in a non-overlapping state by causing the intake side VVT controller to rotate the intake cam relative to the crankshaft toward the advance side or the retard side. Here, in particular, the engine 100 according to the present embodiment is an in-line four-cylinder engine, and the operation stroke of each cylinder differs by 180 degrees in terms of crank angle. For this reason, in this embodiment, the intake / exhaust valves of a plurality of cylinders do not overlap at the same time, and the intake / exhaust valves are in an overlapped state with the exhaust TDC (Top Death Center) sandwiched between them. It is a cylinder in which the piston is located in the region. In consideration of this point, at least in the present embodiment, when the cam position of the intake cam is adjusted to the advance side, the intake valve is driven to open more and the overlap state tends to be further expanded. For this reason, the cam position of the intake cam is basically adjusted on the retard side. When the intake / exhaust valve shifts to the non-overlap state via step 54, the process proceeds to step S55.

  The adjustment mode of the cam position of the intake cam in this embodiment is merely an example, and the cam position adjustment method depends on the cylinder arrangement of the engine (for example, in-line type, V type, or horizontally opposed type), the number of cylinders, and the like. May vary as appropriate.

  In step S55, a scavenging process is executed. In the present embodiment, the scavenging process refers to a process in which the EGR valve 45 is fully opened and the compressor of the electric turbo 23 is rotationally driven at a predetermined rotational speed (or supercharging pressure). As a result of this scavenging process, all of the intake air introduced from the intake passage 21 to the intake manifold 26 is led to the EGR passage 43 because the intake and exhaust valves are non-overlapping in all cylinders of the engine 100. The EGR passage 43 and the EGR cooler 42 are scavenged. The intake air used for this scavenging is discharged to the exhaust manifold 42.

  On the other hand, when the scavenging process is performed in step S55, the scavenging control unit 32 starts measuring the operating time of the electric turbo 23 by the built-in timer, and whether or not the operating time of the electric turbo 23 has reached the set time. Is determined (step S56). When the operating time does not reach the set time (step S56: NO), the driving of the electric turbo 23 is continued, and when the operating time reaches the set time (step S56: YES), the scavenging control unit 32 determines the EGR valve 45. Is fully closed and the electric turbo 23 is stopped (step S57). When step S57 is performed, the first scavenging control process ends.

  When the scavenging process according to step S55 is executed in this way, the interval until the first scavenging control process is started again is the same as the interval when step S51 or step S52 branches to the NO side. The first scavenging control process is not restarted as long as the engine 100 is maintained in the stopped state.

  In the present embodiment, the set time for driving the electric turbo 23 is set in advance so that no deposit is generated in the EGR passage 43 experimentally, empirically, theoretically, or based on simulation. The time is set so that the inside can be scavenged. In accordance with such a purpose, the set time also varies depending on the supercharging pressure of the electric turbo 23 in the scavenging process (that is, the level of the supercharging pressure corresponds to the length of the set time). Therefore, ECU30 may hold | maintain the map which the scavenging control part 32 which associates a supercharging pressure and setting time, for example can refer in ROM etc., for example. In addition, if the interval (that is, the engine operation period) after the previous scavenging process is changed, the degree of deposit generation in the EGR passage 43 may also be changed. It may be associated with the degree of seed deposit generation.

  As described above, according to the first scavenging control process of the present embodiment, when the engine 100 is stopped, the detected storage amount SOC1 of the battery 15 exceeds the reference value SOC0, and the intake valves and the exhaust valves are non-overlapping for all the cylinders. In the state, a scavenging process is performed in which the EGR valve 45 is fully opened and the electric turbo 23 is driven for a predetermined time. As a result, the pressurized intake air flows from the intake passage 21 through the EGR passage 43 to the exhaust passage 41 in a concentrated manner for a predetermined time, so that the inside of the EGR passage 43 or the EGR cooler 44 is efficiently scavenged. Therefore, it is possible to reliably avoid the generation and adhesion of deposits in the EGR passage 43 and the EGR cooler 44.

  In the present embodiment, an intake side VVT controller is used to make the intake and exhaust valves non-overlapping. However, instead of or in addition to such an intake side cam position variable device, the exhaust side A cam position varying device on the exhaust side such as a VVT controller may be provided as an example of the open / close state varying means according to the present invention. Alternatively, as already described, since the generator 13 can transmit torque to the crankshaft via the sun gear and the planetary carrier, the generator 13 rotates the crankshaft while the engine 100 is stopped, The intake / exhaust valve of each cylinder may be controlled to a non-overlapping state. That is, the generator 13 can also be an example of the open / close state varying means according to the present invention.

<Second Embodiment>
Next, with reference to FIG. 4, the 2nd scavenging control process replaced with the 1st scavenging control process in 1st Embodiment is demonstrated as 2nd Embodiment of this invention. FIG. 4 is a flowchart of the second scavenging control process. 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. Further, it is assumed that the various system configurations according to the second embodiment are the same as the hybrid vehicle 200 according to the first embodiment.

  4, first, the scavenging control unit 32 determines whether or not there is a request to stop the engine 100 (step S61). The stop request can be generated artificially or automatically as described in the first embodiment. As a result of this determination, when it is determined that there is no stop request (step S61: NO), the second scavenging control process ends.

  On the other hand, when it is determined as a result of the determination in step S61 that there is a request to stop engine 100 (step S61: YES), it is determined whether or not detected storage amount SOC1 is larger than reference value SOC0 (step S52). Here, in the present embodiment, when it is determined that the detected storage amount SOC1 is greater than the reference value SOC0 (step S52: YES), the scavenging control unit 32 performs an engine stop process with adjustment of the cam position ( Step S62).

  Here, the engine stop process with adjustment of the cam position according to step S62 means that the engine 100 is stopped without performing control of the intake side VVT controller using power resources as shown in the first embodiment. This refers to the process of stopping the engine 100 so that the intake and exhaust valves are in a non-overlapping state for all cylinders at the time. At this time, the scavenging control unit 32 executes the opening / closing control of the throttle 25, the fuel injection amount control of the injector, and the like according to the engine speed NE at the time when the stop request is generated and the opening / closing state of the intake / exhaust valve in each cylinder. The intake / exhaust valves of all cylinders are stopped in a non-overlapping state. Normally, when the engine 100 is stopped, the throttle 25 is closed and the fuel injection is stopped. In this embodiment, the scavenging control unit 32 is preliminarily mapped and stored in an appropriate storage means. These are controlled based on the conditions, and the operating speed of the piston in the inertial drive range is delayed and the stop timing of fuel injection is delayed without departing from the control range of the engine stop control that is normally performed.

  Here, the engine stop accompanied by the adjustment of the cam position is realized by the control of the throttle 25 and the injector. However, torque is applied from the generator 13 to the crankshaft of the engine 100 via the power split mechanism 11. Thus, the cam position (ie, valve position) of each cylinder until the engine 100 is stopped may be controlled.

  When step S62 is executed, the EGR valve 45 is fully opened, the electric turbo 23 is driven (step S55), and the electric turbo 23 is driven for a predetermined time (step S56 :) as in the first scavenging control process. YES), the EGR valve 45 is fully closed, and the drive of the electric turbo 23 is stopped (step S57). The second scavenging control process is performed in this way.

  As described above, according to the second scavenging control process according to the present embodiment, if the detected storage amount SOC1 of the battery 15 exceeds the reference value SOC0, the intake and exhaust valves are in a non-overlapping state for all cylinders. Engine 100 is stopped to stop. For this reason, after stopping the engine, for example, it is possible to clearly suppress the consumption of power resources as compared with the case where the intake and exhaust valves are shifted to the non-overlap state via the drive control of the intake side VVT controller, for example. Accordingly, it is possible to increase the execution frequency of the scavenging process using the EGR valve 45 and the electric turbo 23, and it is possible to more reliably avoid the generation and adhesion of deposits in the EGR passage 43 and the EGR cooler 44. is there.

<Third Embodiment>
Next, a third scavenging control process will be described as a third embodiment of the present invention with reference to FIG. FIG. 5 is a flowchart of the third scavenging control process. 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 addition, the various system configurations according to the third embodiment are the same as the hybrid vehicle 200 according to the first and second embodiments.

  5, first, similarly to steps S61, S52, and S62 of the second scavenging control process in FIG. 4, it is determined whether or not there is a stop request for engine 100 (step S61), and it is determined that there is a stop request. If it is determined (step S61: YES), it is determined whether or not the detected power storage amount SOC1 is greater than the reference value SOC0 (step S52), and if it is determined that the detected power storage amount SOC1 is greater than the reference value SOC0 (step S52). S52: YES), an engine stop process with adjustment of the cam position (that is, a process of stopping the engine 100 so that the intake and exhaust valves of each cylinder stop in a non-overlapping state) is executed (step S62).

  On the other hand, when engine 100 is stopped in step S62, scavenging control unit 32 determines whether or not cooling water temperature Tw1 detected by the water temperature sensor is equal to or lower than reference value Tw0 (step S63). As a result of this determination, when it is determined that the cooling water temperature Tw1 of the engine 100 is higher than the reference value Tw0 (step S63: NO), the scavenging control unit 32 repeatedly executes step S63 so that the detected cooling water temperature Tw1 is the reference value. The process is substantially controlled to be in a standby state until Tw0 or less. The reference value Tw0 is experimentally determined in advance as a temperature at which the water in the EGR gas is condensed and easily generated as condensed water in the EGR passage 43 and the EGR cooler 44 in a temperature range below that.

  On the other hand, if the result of determination in step S63 is that the cooling water temperature Tw1 has become equal to or lower than the reference value Tw0 (step S63: YES), the EGR valve is the same as in steps S55 to S57 of the first and second scavenging control processes. 45 is fully opened and the electric turbo 23 is driven (step S55). After the electric turbo 23 is driven for a predetermined time (step S56: YES), the EGR valve 45 is fully closed and the electric turbo 23 is driven. Stopped (step S57). The third scavenging control process is performed in this way.

  As described above, according to the third scavenging control process according to the present embodiment, the detected charged amount SOC1 of the battery 15 exceeds the reference value SOC0, the engine stop process with cam position adjustment is performed, and the cooling water temperature of the engine 100 is set. When Tw1 falls below the reference value Tw0, the pressurized intake air flows from the intake passage 21 through the EGR passage 41 to the exhaust passage 28 in a concentrated manner for a predetermined time. Therefore, it is possible to suitably remove the condensed water from the EGR passage 43, and it is possible to reliably avoid deposits on the EGR passage 43 and the EGR cooler 42.

<Fourth embodiment>
Next, a fourth scavenging control process will be described as a fourth embodiment of the present invention with reference to FIG. FIG. 6 is a flowchart of the fourth scavenging control process. In the figure, the same reference numerals are assigned to the same parts as those in FIG. 5, and the description thereof is omitted as appropriate. Various system configurations according to the fourth embodiment are the same as the hybrid vehicle 200 according to the first to third embodiments except for the following points.

  That is, in the present embodiment, the battery 15 is configured to be appropriately charged with electric power obtained from various external power sources such as a household power outlet, and the hybrid vehicle 200 is configured as a so-called plug-in hybrid vehicle. In this respect, the configuration is different from those of the first to third embodiments.

  In FIG. 6, first, similarly to the second and third scavenging control processes described above, it is determined whether or not there is a request for stopping the engine 100 (step S61). Step S61: YES), it is determined whether or not the detected power storage amount SOC1 is larger than the reference value SOC0 (Step S52). Here, in the present embodiment, when it is determined as a result of this determination that the detected storage amount SOC1 is equal to or less than the reference value SOC0 (step S52: NO), the process returns to step S61. That is, the process is substantially in a standby state until the detected power storage amount SOC1 becomes larger than the reference value SOC0.

  Here, in particular, in the present embodiment, when step S52 branches to the NO side (that is, when the detected storage amount SOC1 is equal to or less than the reference value), the scavenging control unit 32 drives the generator 13 in the power generation region. Thus, efforts are made to recover the SOC of the battery 15. That is, when the engine stop request according to step S61 is artificially generated by reflecting the driver's intention by the ignition off operation or the like, the engine 100 is operated only for power generation, and the engine stop request is When this occurs to switch the driving mode of the hybrid vehicle 200 to EV driving, the switching of the driving mode is temporarily postponed so that the driver does not feel uncomfortable (that is, the normal hybrid driving range). We will generate electricity as much as possible.

  In view of the fact that the hybrid vehicle 200 is a plug-in hybrid vehicle that can freely charge the battery 15 as compared to a hybrid vehicle having a configuration in which the battery 15 is not charged by an external power source, the decrease in the SOC of the battery 15 is: It is more acceptable than this type of hybrid vehicle. Therefore, the reference value according to step S52 may be set to a value smaller than the reference value SOC0.

  On the other hand, as a result of the determination in step S52, when it is determined that the detected charged amount SOC1 is greater than the reference value SOC0 or the charge has progressed to become greater than the reference value SOC0 (step S52: YES), the third embodiment is performed. The process after step S62 is performed similarly to the 3rd scavenging control process which concerns. The fourth scavenging control process is performed in this way.

  As described above, according to the fourth scavenging control process according to the present embodiment, the scavenging process using the EGR valve 45 and the electric turbo 23 is reliably executed when a stop request for the engine 100 is generated. . Here, in the plug-in hybrid vehicle, the basic travel mode is the EV mode, and the engine 100 is more likely to be an auxiliary power source. Therefore, in the present embodiment, compared to the first to third embodiments, the engine 100 easily falls into a cold state, and condensed water is easily generated in the exhaust passage 41 in addition to the EGR passage 43. In that regard, according to the fourth scavenging control process, since the scavenging process is reliably performed when the engine is stopped, the scavenging frequency of the EGR passage 43 and the exhaust passage 41 communicating with the EGR passage 43 is secured, and deposit generation and adhesion are preferable. It will be avoided.

<Fifth Embodiment>
Next, a fifth scavenging control process will be described as a fifth embodiment of the present invention with reference to FIG. FIG. 7 is a flowchart of the fifth scavenging control process. In the figure, the same reference numerals are assigned to the same parts as those in FIG. 5, and the description thereof is omitted as appropriate. Various system configurations according to the fifth embodiment are the same as the hybrid vehicle 200 according to the first to third embodiments except for the following points.

  That is, in the present embodiment, the engine 100 is configured so that a mixed fuel of ethanol and gasoline can be used as the fuel, and the mixing ratio thereof is free (that is, it can operate with only ethanol or only gasoline). The hybrid vehicle 200 is a so-called FFV (Flexible Fuel Vehicle). In the present embodiment, the hybrid vehicle 200 includes a fuel property sensor capable of detecting the ethanol concentration and the water concentration in the fuel in the fuel tank.

  In FIG. 7, the scavenging control unit 32 first acquires the fuel property from the fuel property sensor (step S71), and compares the acquired fuel property with the reference value to thereby determine the ethanol concentration in the fuel or the water content in the ethanol. It is determined whether or not the density is high (step S72). This reference value is a conforming value determined experimentally in advance. As a result of this determination, if it is determined that neither the ethanol concentration nor the water concentration is high (step S72: NO), the process proceeds to step S61.

  On the other hand, as a result of the determination in step S72, when it is determined that the ethanol concentration or the water concentration is high (step S72: YES), the reference value SOC0 used for comparison with the detected storage amount SOC1 is corrected to the decreasing side. (Step S73). When the correction of the reference value SOC0 is completed, the process proceeds to step S61. The reference value SOC0 may be corrected to the decreasing side in a binary manner, or may be corrected to the decreasing side stepwise or continuously in accordance with the ethanol concentration or the water concentration. Step S61 and subsequent steps are the same as the third scavenging control process according to the third embodiment. The fifth scavenging control process is performed in this way.

  As described above, according to the fifth scavenging control process according to the present embodiment, the reference value SOC0 that defines the scavenging process execution opportunity is corrected appropriately to the decreasing side according to the ethanol concentration or the water concentration in the fuel. The For this reason, in this embodiment, compared with the 3rd early control processing, for example, the execution frequency of scavenging processing increases.

  Here, in particular, ethanol generates about twice as much water as gasoline during combustion. Therefore, the level of the ethanol concentration in the fuel can be directly related to the amount of water in the exhaust passage 41 and the EGR passage 43. In addition, the tendency becomes more remarkable with a fuel having a relatively high water concentration in ethanol, which is referred to as a so-called poor fuel. That is, in this type of FFV engine, deposits are likely to be generated in the exhaust passage and the EGR passage. In this respect, according to the present embodiment, the frequency of the scavenging process can be increased, so that the generation and adhesion of deposits in the exhaust passage 41 and the EGR passage 43 can be reliably avoided.

  In the present embodiment, the reference value SOC0 is corrected to the decreasing side. However, from the viewpoint of increasing the execution frequency of the scavenging process, as described in the fourth embodiment, the scavenging process is reliably performed when the engine is stopped. As can be done, in the SOC region below the reference value SOC0, the generator 13 may generate power forcibly halfway and try to recover the SOC. In that case, it is not always necessary to correct the reference value.

  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.

1 is a block diagram conceptually showing the configuration of a hybrid vehicle according to a first embodiment of the present invention. FIG. 2 is a schematic configuration diagram conceptually showing a configuration of an internal combustion engine and an ECU in the hybrid vehicle of FIG. 1. 2 is a flowchart of a first scavenging control process executed by a scavenging control unit of an ECU in the hybrid vehicle of FIG. 1. It is a flowchart of the 2nd scavenging control process which concerns on 2nd Embodiment of this invention. It is a flowchart of the 3rd scavenging control process which concerns on 3rd Embodiment of this invention. It is a flowchart of the 4th scavenging control process which concerns on 4th Embodiment of this invention. It is a flowchart of the 5th scavenging control process which concerns on 5th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Main-body part, 21 ... Intake flow path, 23 ... Electric turbo, 30 ... ECU, 31 ... Valve state detection part, 32 ... Scavenging control part, 41 ... Exhaust flow path, 43 ... EGR passage, 44 ... EGR cooler, 45 ... EGR valve, 100 ... Engine, 200 ... Hybrid car

Claims (6)

A supercharger mounted on a vehicle and configured to be driven by a predetermined driving means disposed in an intake flow path, and the supercharger having one end connected to an exhaust flow path and the other end in the intake flow path An EGR passage that is connected further downstream and can recirculate EGR gas, which is part of exhaust gas, to the intake passage, and an adjustment means that can adjust the flow rate of the EGR gas in the EGR passage. An internal combustion engine control device comprising:
A specifying means for specifying an open / close state of an intake valve and an exhaust valve in each of the cylinders of the internal combustion engine;
Based on the specified open / close state, the exhaust flow from the intake flow path through the EGR passage when the internal combustion engine is stopped and the intake valve and the exhaust valve are in a predetermined non-overlap state. And a control means for controlling the supercharger and the adjusting means so that the intake air flows into the road. 2. The control device for an internal combustion engine according to claim 1, wherein the control unit controls the adjustment unit so that a flow rate of intake air flowing through the EGR passage is maximized. 3. The vehicle further includes an open / close state variable means capable of changing the open / close state,
The control means is configured so that, when the internal combustion engine is stopped, the intake valve and the exhaust valve are in the non-overlapping state for each of the control units before and after the control of the supercharger and the adjustment unit. The control device for an internal combustion engine according to claim 1 or 2, wherein the open / close state varying means is controlled. The control means stops the internal combustion engine so that the intake valve and the exhaust valve stop in the non-overlapping state in response to a stop request indicating that the internal combustion engine should be stopped. The control device for an internal combustion engine according to any one of claims 1 to 3. 5. The vehicle according to claim 1, wherein the vehicle is a hybrid vehicle that functions as a power source together with the internal combustion engine and includes at least one electric motor that is driven by power supply via a power storage unit. The control apparatus for an internal combustion engine according to one item. The control device for an internal combustion engine according to any one of claims 1 to 5, wherein the driving means includes an electric motor.

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