JP2009270440A - Intake control device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid falling into an uncontrollable state of at least an intake control valve, when driving voltage is reduced, in driving control of the intake control valve for performing inertial supercharging. <P>SOLUTION: An engine system 10 has an engine 200 having an impulse valve 224 common to the whole cylinders equipped in the engine 200 in a communicating tube 206 arranged downstream of a surge tank 223, and executes driving control of an impulse valve in an impulse charge area. In valve opening control in this control, an ECU 100 corrects a valve opening side switching angle ζ1 for expressing a rotation angle of a rotor for transferring a driving current Iq to PID control, to the reduction side in response to a reduction degree of driving voltage Vdc, and similarly in valve closing control, corrects a valve closing side control switching angle ζ2 for expressing the rotation angle of the rotor for transferring the driving current Iq to the PID control, to the increase side in response to the reduction degree of the driving voltage Vdc. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technical field of an intake control device for an internal combustion engine that includes an intake control valve capable of generating intake air pulsation and is configured to be capable of inertial supercharging by the intake pulsation.

  A valve that performs feedback control by PID has been proposed for driving control of a valve different from this type of intake control valve (see, for example, Patent Document 1). According to the continuous quantity control method disclosed in Patent Document 1 (hereinafter referred to as “prior art”), the PID proportional constant is based on the ratio between the valve drive voltage in the table storage unit and the actual valve drive voltage. In addition, it is disclosed that good followability is ensured by rewriting at least one of the integration constant and the stored learning value.

  Regarding throttle valve drive control, a technique has also been proposed in which the duty drive on-time is controlled to be long when the drive voltage is low (see, for example, Patent Document 2).

  Similarly, regarding the drive control of the throttle valve, a technique for reducing the motor drive speed when the motor drive voltage is reduced has been proposed (see, for example, Patent Document 3).

  Furthermore, a technique has been proposed in which the opening target is a fixed value when the drive voltage is reduced (see, for example, Patent Document 4).

  Furthermore, a technique for changing the driving speed between valve opening driving and valve closing driving to ensure responsiveness and driving torque has been proposed (see, for example, Patent Document 5).

JP-A-9-217898 JP-A-10-176549 JP-A-61-226540 JP-A-11-294194 JP 11-294196 A

  Since the intake control valve for performing the inertia supercharging is, for example, binary and repeatedly controlled between the fully open position and the fully closed position, in addition to the followability of the valve, the target opening (for example, the fully open position) Alternatively, convergence to a fully closed opening degree is required. Here, the drive voltage for driving the intake control valve, such as an actuator, is easily influenced by the operating state of the internal combustion engine or the peripheral device, but the control parameters for the actuator and the like are adapted to the drive voltage assumed in advance. When this type of drive voltage change, particularly a decrease in drive voltage, feedback control such as PID control becomes difficult to work effectively, and it may be difficult to stop the valve at the target opening. . In some cases, the valve can also become uncontrollable.

  Here, in particular, in the conventional technique, a driving voltage as a learning value (or initial value) is set according to the flow rate setting value, and this initial value or learning value is appropriately set according to the actual driving voltage, or PID control. Since only the parameters are updated, no decrease in drive voltage that can occur randomly each time is taken into account. Therefore, when the conventional technology is applied to the drive control of the intake control valve for performing the inertia supercharging regardless of whether the application is easy or not, the intake control valve is It is extremely difficult in practice to avoid a situation where an uncontrollable state occurs.

  The present invention has been made in view of the above-described problems, and at the time of drive control of the intake control valve for performing inertia supercharging, when the drive voltage decreases, at least the intake control valve falls into an uncontrollable state. An object of the present invention is to provide an intake control device for an internal combustion engine that can avoid this.

  In order to solve the above-described problems, at least one intake control device for an internal combustion engine according to the present invention is installed in a plurality of cylinders and an intake passage communicating with the plurality of cylinders, and opens and closes with predetermined opening / closing control. An internal combustion engine comprising an intake control valve configured to be capable of inertia supercharging utilizing intake air pulsation in accordance with a change in state, and drive means capable of applying a drive force for the change in the open / close state to the intake control valve An intake control device for an engine, the specifying means for specifying the opening degree of the intake control valve, and the opening / closing control, in the opening / closing control, based on the specified opening degree and a predetermined type of control parameter. The control means for controlling the drive means so that the degree converges to the target value, and the convergence when the opening of the intake control valve converges to the target value according to the degree of decrease in the drive voltage in the drive means sex Characterized by comprising a changing means for changing the control parameters in a direction which decreases is suppressed.

  The "internal combustion engine" according to the present invention has a plurality of cylinders, and various fuels such as gasoline, light oil, various alcohols, or a mixed fuel of various alcohols and gasoline, or the like in each of the cylinders, or The force generated when an air-fuel mixture containing various fuels explodes or burns can be taken out as a driving force through a physical or mechanical transmission path such as a piston, a connecting rod and a crankshaft. It is a concept that encompasses various institutions. An “intake engine control device for an internal combustion engine” relating to this type of internal combustion engine includes intake air (ie, intake air as air sucked from the outside world) as a part of the concept, and the intake air itself. Or, for example, when an exhaust gas recirculation device such as an EGR device is provided, for example, a mixture of EGR gas (that is, a part of exhaust gas) and the intake air according to the open / close state of a flow rate adjusting means such as an EGR valve, etc. The device can control the supply of various forms of the above.

  The “intake passage” according to the present invention is the intake passage described above. As a preferable form, for example, an air cleaner, an air flow meter, a throttle valve (ie, an intake throttle valve), a surge tank, an intake port, etc. Can be connected or communicated with each other as appropriate, for example, in the form of a single or multiple tubular members. Further, as a preferred embodiment, the internal combustion engine according to the present invention is a part formed by excluding a part to be provided in an exhaust system such as a turbocharger (of course, a turbine or the like) in the intake passage. In this case, the downstream side (in addition, “downstream” and “upstream” is one of the directional concepts based on the direction of intake air flow. In this case, An intake air cooling means such as an intercooler may be provided on the downstream side (that is, the cylinder side). The intake air cooling means is a physical unit capable of cooling intake air supplied via a supercharger (may be irrelevant whether or not supercharging by the supercharger is performed in practice). Means having mechanical, mechanical, electrical, magnetic or chemical aspects, at least somewhat more and relatively cooling the intake air, thereby increasing the intake air density relatively Efficiency can be improved.

  An internal combustion engine according to the present invention is provided with an intake control valve in an intake passage, which can adjust an intake air amount as an intake air amount according to an open / close state that can be controlled, for example, in a binary, stepwise or continuous manner. When the internal combustion engine is provided with a so-called intake throttle valve such as a throttle valve, the intake control valve is installed on the downstream side of the intake throttle valve as a preferred form. The installation mode of the intake control valve can be appropriately changed according to the structure of the intake passage. For example, in the case where the intake passage has a configuration that appropriately branches in the section between the surge tank and each cylinder, for example, corresponding to each cylinder or cylinder group, a plurality of intake passages are provided at the branch position or upstream thereof. A single intake control valve may be provided so as to be shared by the cylinders (in this case, the intake system may be a so-called single valve intake manifold intake system). Also in the configuration of a simple intake passage, a plurality of intake control valves may be provided for each cylinder individually in a plurality of intake passages corresponding to each cylinder (that is, downstream of the branch position) (so-called multi-valve in-maniless intake system) ). Alternatively, when a part of the intake passage is a so-called intake manifold or the like, for example, an independent configuration for each cylinder on the downstream side of the surge tank, it is needless to say that intake control is performed on each (or part of) these independent pipes. A valve may be provided.

  The intake control valve according to the present invention is configured to be capable of generating intake air pulsation through predetermined opening / closing control for controlling the open / closed state of the intake valve, whether single or plural, and uses the intake pulsation. Inertia supercharging (also referred to as pulse supercharging or impulse charge) can be realized.

  Here, the “predetermined opening / closing control” is, for example, the opening / closing timing, opening period or opening degree of the intake control valve (that is, the degree of opening of the intake control valve) to achieve this kind of inertia supercharging. The control of the intake valve opening and closing timing or valve opening period, or the correction of the fuel injection amount according to the change in the intake amount accompanying the change in the intake charging efficiency For example, the closing timing of the intake valve (that is, a valve for controlling the communication state between the combustion chamber and the intake passage as a preferred embodiment) and the peak of the intake pulsation wave (positive pressure wave) reach the intake valve. This includes the control to synchronize with the time to be performed (it does not necessarily represent only matching).

  More specifically, the open / close control is, for example, that the intake control valve is opened after an appropriate time elapse (may be defined as an angle concept by a crank angle or the like) after the intake valve is opened (that is, the intake control). Combustion chamber of each cylinder that generates a positive pressure wave by opening the valve in a state where the downstream side of the valve is negative pressure and the upstream side of the intake control valve is at or above atmospheric pressure, etc. When a negative pressure wave is reflected in the vicinity of the entrance and this negative pressure wave is reflected at the open end of the tank again at the open end, so-called secondary positive pressure wave is used, for example, when natural intake is performed (a suitable one) As a form, the intake air can be basically taken into the cylinder as a pulsation wave regardless of the presence or absence of the intake control valve, but the pulsation caused by the opening / closing control applied to the intake control valve is a suitable form. The pulsation of Also meant to comprise control, etc. to be made to incorporate a strong pulsation in a) compared to the cylinder in the intake stroke a large amount of intake air.

  The intake control device for a first internal combustion engine according to the present invention is configured as various processing units such as an ECU (Electronic Control Unit), various controllers, various computer systems such as a microcomputer device, or the like when operating. The opening degree of the intake control valve is specified by specifying means that can be used.

  “Specific” in the present invention refers to, for example, detecting a specific target (here, the opening degree of the intake control valve) or a physical quantity or control amount correlated with the specific target directly or indirectly via some detection means. Based on the physical quantity or control amount detected in this way, selecting a specific target object, physical quantity or control amount from a map or the like stored in advance in an appropriate storage means or the like, such detection or selection Deriving a specific target, physical quantity or control quantity from a physical quantity or control quantity according to a preset algorithm or calculation formula, etc., or a specific target, physical quantity or This is a broad concept including simply acquiring control amounts in the form of, for example, electrical signals, etc., and the specifying means is, for example, within the scope of the concept. The opening degree is determined based on the rotational angle or rotational phase obtained through various detecting means configured to detect the rotational angle or rotational phase of the intake control valve, such as a resolver, a hall sensor, or a rotary encoder. The rotation angle or the rotation phase itself may be used as the opening index value.

  On the other hand, according to the intake control device for the first internal combustion engine according to the present invention, the control means that can be configured as various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device, etc. In the open / close control defined by the above concept, based on the specified opening and a predetermined type of control parameter, an appropriate driving force is applied to the intake control valve so that the opening of the intake control valve converges to a target value. The driving means according to the present invention, which can take a form including, for example, an electrically driven motor or an actuator configured to be impartable, is controlled.

  Here, the “predetermined type of control parameter” may be defined by convergence (for example, transition time, ease of convergence, convergence accuracy, etc.) when the opening of the intake control valve is converged to a target value. ) Is a concept encompassing parameters that can define quite a considerable amount, and various modes can be adopted depending on the mode of convergence control.

  For example, when the opening of the intake control valve is converged to the target value, the control parameter is used when the drive current is controlled using feedback control such as PID control according to the deviation between the target value and the current value. Is a proportional gain in each of a proportional term (hereinafter referred to as “P term” as appropriate), an integral term (hereinafter referred to as “I term” as appropriate) or a differential term (hereinafter referred to as “D term” as appropriate), An integral gain or a differential gain may be included as appropriate. Alternatively, for example, as a pre-stage of this type of PID control, at least in a range in which no overshoot with respect to the target value occurs (that is, set between the current opening degree and the target value, that is, to a provisional target value). The opening of the intake control valve may be driven as fast as theoretically, practically or practically under some constraints, in which case this kind of provisional target value, or The opening / closing speed of the intake control valve (which may be a driving force of a driving means that defines the intake control valve or various physical amounts or control amounts corresponding to the driving force) may be adopted as a control parameter. In addition, as long as the opening degree of the intake control valve can be converged to the target value, various modes such as rectangular wave current control and vector control can be adopted as the drive current control mode.

  It should be noted that such control of the driving means related to the control means may be executed as part of the opening / closing control, or may be executed in a separate system from the opening / closing control. In addition to the control of this type of drive means, the control means may control the above-described open / close control whether the control of this type of drive means is executed as a part of the open / close control. May be further executable.

  Here, the driving force applied by the driving means is the driving voltage (for example, when the driving force source of the driving means includes various electric motors such as a DC brushless motor having a rotor and a stator coil, for example). In the case of a DC brushless motor, it is affected by the DC applied voltage). As a more specific example, for example, when the drive voltage is not in the design value (or design range) defined in advance, the inductance of the stator coil changes, and the applied current value such as a three-phase alternating current is, for example, In particular, the rise characteristic changes.

  In this case, the rotor is not provided with the rotational driving force as designed, and the above-described various control parameters adapted to this type of designed value are difficult to function effectively, and the opening degree of the intake control valve becomes the target. It becomes difficult to converge to the value. Or, the transition time required for the convergence becomes longer.

  Such a decrease in convergence is, in particular, the flow of intake air to a fully open state (to the extent that it can be regarded as fully open) mainly in the intake stroke (the time required for this can vary depending on the vehicle operating conditions, particularly the engine speed). Open / close state substantially binary between a fully closed state (including a valve open state that does not obstruct) and a fully closed state (including a closed state that can create a negative pressure to the extent that there is no practical problem downstream of the intake control valve) In the opening / closing control of the intake control valve that needs to be repeatedly controlled, the intake control valve may substantially fall into an uncontrollable state. If the intake control valve becomes uncontrollable, whether the intake control valve is switched from fully open to fully closed or from fully closed to fully open, the effect of improving the charging efficiency of the intake air due to inertia supercharging is hindered. In some cases, the engine flow of the internal combustion engine may be stopped (so-called engine stall) due to interruption of the flow of intake air.

  However, the drive voltage of the drive means is supplied from an in-vehicle battery as a preferred form. In addition, this type of vehicle-mounted battery often has a configuration in which an appropriate power supply is received and stored from a power generation system including an alternator, a DC / DC converter, and the like as a preferred embodiment. Accordingly, the drive voltage of the drive means is likely to change frequently depending on various conditions such as the operating state of the internal combustion engine or the running state of the vehicle. Further, when a battery having a relatively large capacity different from a so-called vehicle-mounted battery is provided like a hybrid vehicle, this kind of decrease in driving voltage is not necessarily eliminated. That is, in order to avoid at least the intake control valve from going into an uncontrollable state, it is necessary to ensure the convergence of the opening degree of the intake control valve against a decrease in the drive voltage of the drive means.

  Therefore, according to the intake control device of the first internal combustion engine according to the present invention, during its operation, it is driven by changing means that can be configured as various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device. The control parameter is changed in a direction in which the convergence is improved when the opening of the intake control valve is converged to the target value in accordance with the degree of decrease in the drive voltage in the means.

  As described above, the control parameter is a control amount that has a considerable influence on the convergence of the intake control valve. Therefore, a decrease in the drive voltage (as a preferred form, a reference value determined in advance as a design value or the like). The change in drive voltage has an effect on the convergence by changing in a direction that suppresses the decrease in convergence in a binary, stepwise or continuous manner according to the degree of the decrease in the drive voltage. However, the convergence of the intake control valve can be ensured. As a result, according to the intake control device for the first internal combustion engine of the present invention, a situation in which the intake control valve falls into an uncontrollable state is avoided. The “direction in which the decrease in convergence” is suppressed is specifically defined according to the type and nature of the control parameter, and each of the individual specific modes includes various types. Embodiments can be taken.

  In one aspect of the intake control apparatus for a first internal combustion engine according to the present invention, the control means generates a drive current of the drive means in a first period until the specified opening degree reaches a predetermined threshold value. While maintaining the predetermined maximum value, the opening of the intake control valve is set to the target value by performing PID control of the drive current based on the specified opening in the second period after the threshold is reached. The changing means changes at least one of the threshold, the PID gain related to the PID control, and the maximum value of the driving current as the control parameter.

  According to this aspect, the control means feeds back the drive current toward the target value by PID control based on the specified opening in the second period after the opening of the intake control valve reaches the threshold. Control. Therefore, the changing means changes the PID gain (that is, at least one of the proportional gain, the integral gain, and the differential gain) (preferably, all change to the increase side with respect to the decrease in the drive voltage). It is possible to suitably suppress a decrease in convergence when the opening of the intake control valve is converged.

  Further, when the drive voltage is decreased, the threshold value for dividing the first period and the second period is changed so that the PID control is started earlier (the change direction of the threshold is preferably the valve opening side). For example, the threshold value may be changed to be smaller on the valve opening side and larger on the valve closing side.) The convergence accuracy (that is, the valve position control accuracy) can be improved in applications that require a high convergence, and the valve can be suitably avoided from being in an uncontrollable state.

  Note that “driving current” refers to various modes depending on the physical, mechanical, electrical, or magnetic configuration of the driving means, or depending on the control mode of the control unit or the control mode during open / close control. obtain. For example, when so-called vector control is performed, the drive current is a dq axis model in which the d axis is set in the direction of the magnetic pole pair of the rotor in the motor constituting the drive means and the q axis is set in the perpendicular direction. The d-axis current or the q-axis current set above may be used. Alternatively, they may be converted into u-phase, v-phase, and w-phase three-phase currents through fixed coordinate conversion of the stator. Further, the “predetermined maximum value” set for the drive current does not have to be a theoretical or substantial maximum value, and as a preferable form, in consideration of some restrictions or based on prior adaptation The maximum control value to be determined.

  Therefore, when the drive voltage is reduced, the maximum value of the drive current is changed (in this case, preferably changed to the increase side), thereby ensuring the drive energy applied to the rotor as much as possible. It is possible to compensate for the delay in the rise of the drive current due to the decrease in the current, and it is possible to suitably suppress the decrease in convergence. In addition, various types of change control related to the suppression of the decrease in convergence of the intake control valve (relatively improved convergence) performed by these changing means may be executed in combination as appropriate.

  In order to solve the above-described problems, at least one intake control device for a second internal combustion engine according to the present invention is installed in a plurality of cylinders and an intake passage communicating with the plurality of cylinders, and opens and closes with predetermined opening / closing control. An intake control device for an internal combustion engine, comprising: an intake control valve capable of generating intake air pulsation by a change in state; and drive means capable of applying a drive force used for the change in the open / closed state to the intake control valve. A means for specifying the opening degree of the intake control valve; and in the opening / closing control, the opening degree of the intake control valve converges to a target value based on the specified opening degree and a predetermined type of control parameter. And a control unit for controlling the driving unit, and a limiting unit for limiting the operation of the intake control valve according to the degree of decrease in the driving voltage in the driving unit.

  According to the intake control device of the second internal combustion engine of the present invention, during the operation, the limiting means that can be configured as various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device, The operation of the intake control valve is limited according to the degree of decrease in the drive voltage. Here, “restricting the operation” is a concept encompassing that the operation mode is somewhat limited as compared with the case where this kind of limitation is not made.

  When the drive voltage is lowered, as described in the intake control device for the first internal combustion engine according to the present invention, for example, the control of the drive current by the control means is affected, and the convergence of the opening degree of the intake control valve is lowered. However, by limiting the operation of the intake control valve, for example, when the drive voltage is reduced to such an extent that such a decrease in convergence can be manifested as a problem that cannot be overlooked in practice, so-called convergence can be said. This makes it possible to prevent the intake control valve from falling into an uncontrollable state by an approach different from the above-described approach for suppressing the decrease in convergence. It becomes.

  In one aspect of the intake control device for a second internal combustion engine according to the present invention, the restriction means initially sets the intake control valve when the drive voltage is not within an operation permission range defined by a predetermined upper and lower limit value. The operation of the intake control valve is limited by fixing the position or changing the operating angle of the intake control valve in accordance with the drive voltage.

  According to this aspect, the limiting means is configured such that the driving voltage is higher (or higher) or lower (or lower), for example, experimentally, empirically, theoretically or based on simulation. ) In the area of (), if the deterioration of the convergence of the intake control valve is not within the operation permission range defined by the upper limit value and the lower limit value defined as something that can hardly be overlooked in practice, intake control As a preferred embodiment, the valve is fixed at the initial position which is the fully open position, or the operating angle of the intake control valve is changed according to the drive voltage.

  For example, in the former case, the opening / closing control itself is prohibited, and although the effect of inertia supercharging cannot be obtained, the possibility that the intake control valve falls into an uncontrollable state is almost zero. On the other hand, in the latter case, the operating angle during the valve opening period or the valve operating period during the valve closing period is changed so that the convergence required for the intake control valve is eased. Yes, the increase / decrease in one working angle causes a decrease in the other working angle), thereby reducing the possibility that a decrease in convergence results in an uncontrollable state. That is, qualitatively speaking, it is possible to give more time to drive the intake control valve. In any case, a situation in which the intake control valve falls into an uncontrollable state can be suitably prevented.

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

<Embodiment of the Invention>
Various preferred embodiments of the present invention will be described below with reference to the drawings.
<First Embodiment>
<Configuration of Embodiment>
First, the configuration of the engine system 10 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram conceptually showing the configuration of the engine system 10.

  In FIG. 1, an engine system 10 is mounted on a vehicle (not shown) and includes an ECU 100 and an engine 200.

  The ECU 100 is an electronic control unit that includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and is configured to be able to control the entire operation of the engine 200. 1 is an example of an “intake control device for an internal combustion engine”. The ECU 100 is configured to execute basic control and impulse valve drive control, which will be described later, in accordance with a control program stored in the ROM.

  The ECU 100 is an integrated electronic control unit configured to function as an example of the “specifying unit”, “control unit”, and “change unit” according to the present invention. The ECU 100 is configured to be executed. 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 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. Then, the air-fuel mixture containing the fuel is compressed in the compression process in each cylinder, and the force generated when ignited by the ignition operation of the ignition device 203 is applied to the crankshaft (not shown) via a piston and a connecting rod (not shown), respectively. It is configured to be converted into a rotational motion. The rotation of the crankshaft is transmitted to drive wheels of a vehicle on which the engine system 10 is mounted, and the vehicle can travel. Below, the principal part structure of the engine 200 is demonstrated with a part of the operation | movement. Since the configurations of the individual cylinders 202 are equal to each other, only one cylinder 202 will be described here. However, when the cylinders are distinguished from each other, each of these four cylinders is appropriately expressed as “first cylinder”, “second cylinder”, “third cylinder”, and “fourth cylinder”. Note that supplementarily, the engine 200 is configured such that each stroke is repeatedly executed in the order of the first cylinder → the third cylinder → the fourth cylinder → the second cylinder.

  In FIG. 1, intake air as air guided from the outside world is guided to the intake pipe 204. The intake pipe 204 is provided with a throttle valve 205 capable of adjusting the amount of intake air guided to the intake pipe 204. The throttle valve 205 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 at the upper level. The rotational position is continuously controlled from a fully closed position where the upstream and downstream portions of the intake pipe 204 at the boundary are substantially blocked to a fully open position where the intake pipe 204 communicates almost entirely. As described above, in the engine 200, the throttle valve 205 and the throttle valve motor constitute a kind of electronically controlled throttle device.

  The intake pipe 204 is connected to the communication pipe 206 on the downstream side of the throttle valve 205 and is configured to communicate with the communication pipe 206 therein. The communication pipe 206 communicates with each intake port (not shown) of each cylinder 202, and the intake air guided to the intake pipe 204 is guided to the intake port corresponding to each cylinder via the communication pipe 206. It is configured to be written. Two intake ports are provided for each cylinder 202, and each intake port is configured to communicate with the inside of the cylinder 202. The intake pipe 204 and the communication pipe 206 constitute an example of the “intake passage” according to the present invention.

  An injection valve of an injector (not shown) for fuel injection is exposed at the intake port, and is configured to be able to inject gasoline as fuel into the intake port. The injector drive system is electrically connected to the ECU 100 and is controlled by the ECU 100 to the upper level. That is, the operation of the injector is controlled by the ECU 100. The fuel injected through the injector is mixed to some extent with the intake air at the intake port, and is sucked into the cylinder 202 in the intake stroke as the above-described mixture. That is, this air-fuel mixture is an example of “intake” according to the present invention. Note that the intake air-fuel mixture is further mixed in the intake stroke and the subsequent compression stroke, and ignited and ignited by ignition control of the ignition device 203 (controlled by the ECU 100) performed in the vicinity of the compression TDC ( That is, it is configured to explode).

  In this embodiment, the injector is a so-called electronically controlled port injector, and fuel is injected into the intake port. However, the fuel injection mode is not limited in any way. For example, this type of port injector is used. Instead of or in addition, an in-cylinder direct injection system composed of, for example, a common rail system or a unit injector that can inject fuel directly into the high-temperature and high-pressure cylinder 202 may be employed.

  The communication state between the intake port and the cylinder 202 is controlled by an intake valve 207 provided in each intake port. The intake valve 207 is fixed to the intake camshaft 208 that rotates in conjunction with the crankshaft. The cam profile of the intake cam 209 that has an elliptical cross section perpendicular to the extending direction of the intake camshaft 208 (in short, The opening / closing characteristics are defined according to the shape), and the intake port and the inside of the cylinder 202 can communicate with each other when the valve is opened.

  On the other hand, the burned mixture or the partially unburned mixture is led to the exhaust manifold 213 through the exhaust port (not shown) as exhaust when the exhaust valve 210 that opens and closes in conjunction with the opening and closing of the intake valve 207 is opened. It is configured to be written. The exhaust valve 210 is fixed to the exhaust camshaft 211 that rotates in conjunction with the crankshaft, and the cam profile of the exhaust cam 212 having an elliptical cross section perpendicular to the extending direction of the exhaust camshaft 211 (in short, The opening / closing characteristics are defined according to the shape), and the exhaust port and the cylinder 202 can be communicated with each other when the valve is opened. The exhaust gas collected in the exhaust manifold 213 is supplied to the exhaust pipe 214 communicating with the exhaust manifold 213.

  A turbine 216 is installed in the exhaust pipe 214 so as to be accommodated in the turbine housing 215. The turbine 216 is a ceramic impeller configured to be rotatable about a predetermined rotation axis by the pressure of exhaust gas (that is, exhaust pressure) guided to the exhaust pipe 214. The rotating shaft of the turbine 216 is shared with the compressor 218 installed in the intake pipe 204 so as to be accommodated in the compressor housing 217. When the turbine 216 is rotated by exhaust pressure, the compressor 218 is also centered on the rotating shaft. It is configured to rotate.

  The compressor 218 is configured to be able to pump and supply intake air sucked into the intake pipe 204 from the outside via the air cleaner 219 to the downstream side by the pressure accompanying its rotation. A so-called supercharging is realized by the pumping effect. That is, in the engine 200, the turbine 216 and the compressor 218 constitute a kind of turbocharger. In the following description, the term “turbocharger” will be used as appropriate as a comprehensive concept including the turbine 216 and the compressor 217.

  A three-way catalyst 219 is installed in the exhaust pipe 214. The three-way catalyst 219 is a catalytic converter that can purify HC (hydrocarbon), CO (carbon monoxide), and NOx (nitrogen oxide) in the exhaust gas simultaneously or continuously. Further, a water temperature sensor 220 is disposed in the cylinder block 201 that accommodates the cylinder 202. Inside the cylinder block 201, a water jacket as a cooling water flow path for cooling the cylinder 202 is stretched. Inside the water jacket, LLC as cooling water is circulated and supplied by the action of a circulation system (not shown). ing. The water temperature sensor 220 has a configuration in which a part of the detection terminal is exposed inside the water jacket, and is configured to be able to detect the temperature of the cooling water. The water temperature sensor 220 is electrically connected to the ECU 100, and the detected coolant temperature is grasped by the ECU 100 at a constant or indefinite period.

  A hot wire type air flow meter 221 capable of detecting the mass flow rate of the intake air is installed on the upstream side of the compressor 218. The air flow meter 221 is electrically connected to the ECU 100, and the detected intake air amount is grasped by the ECU 100 at a constant or indefinite period. In the present embodiment, the detected intake air amount is uniquely related to the amount of intake air (ie, the intake air amount) sucked into the cylinder 202, and is an index that defines the actual load of the engine 200. Treated as a value.

  In the intake pipe 204, an intercooler 222 is installed on the downstream side of the compressor 218 and the upstream side of the throttle valve 205. The intercooler 222 has a heat exchange wall inside thereof, and when supercharged intake air passes (the same is true even in a low rotation region where the compressor 218 does not act substantially), The intake air can be cooled by heat exchange via the heat exchange wall. The engine 200 can increase the density of the intake air by the cooling by the intercooler 222, so that the supercharging via the compressor 218 can be performed more efficiently.

  Here, a surge tank 223 is installed on the downstream side of the throttle valve 205 in the intake pipe 204. The surge tank 223 suppresses irregular pulsation of the intake air supplied while appropriately receiving the above-described turbocharger supercharging action, and stably supplies the intake air to the downstream side (that is, the cylinder 202 side). At the same time, the storage means is configured to be able to invert the phase of the negative pressure wave during the execution of inertia supercharging control, which will be described later, and the above-described communication pipe 206 is located on the downstream side of the surge tank 223. It is connected to the. However, since the intake air is basically supplied to the cylinder 202 while pulsating to a greater or lesser extent, the intake air passing through the surge tank 223 is also a kind of pulsating wave.

  A single impulse valve 224 is provided in the vicinity of the connection portion with the communication pipe 206 on the downstream side of the surge tank 223 installed in the intake pipe 204. The impulse valve 224 has an opening degree defined by the position of the valve body, a fully-closed opening degree that blocks communication between the intake pipe 204 and the communication pipe 206, and almost complete communication between the intake pipe 204 and the communication pipe 206. 1 is a valve device that is an example of an “intake control valve” according to the present invention that is configured to continuously change between the fully opened opening.

  Here, the details of the impulse valve 224 will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view around the impulse valve 224. 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 impulse valve 224 includes a valve body 224A and a rotating shaft 224B.

  The valve body 224A is a rotating body configured to be rotatable in a plane in the illustrated cross section. The valve body 224 </ b> A allows the fully closed position CL illustrated in FIG. 5 to block communication between the surge tank 223 and the communication pipe 206, and the surge tank 223 and the communication pipe 206 almost entirely through drive control via the IPVEDU 225 described later. The rotational position is controlled between the fully open position OP shown in the figure.

  As is apparent from the drawing, the difference in the opening angle of the valve body 224A between the fully open position OP and the fully closed position CL is 90 °. In addition, hereinafter, the degree of opening and closing of the valve body 224A will be appropriately expressed by the term “opening”, and the opening corresponding to the fully closed position CL corresponds to “fully closed opening” as appropriate, and also corresponds to the fully open position OP. The opening is appropriately expressed as “fully closed opening”. For convenience, it is assumed that the opening angle of the valve body 224A corresponding to the fully closed opening is 0 degree and the opening angle of the valve body 224A corresponding to the fully opening is 90 degrees. In the following description, the valve body 224A and the impulse valve 224 are used without distinction unless otherwise specified for the purpose of preventing the description from becoming complicated. That is, for example, “the opening degree of the impulse valve 224” or “the opening angle of the impulse valve 224” is equivalent to “the opening degree of the valve body 224A” or “the opening angle of the valve body 224A”.

  The rotation shaft 224B is a shaft body that defines the rotation center of the valve body 224A, and is connected to the rotation shaft of the drive motor in the IPVEDU 225 described later.

  Returning to FIG. 1, the IPVEDU (Impulse Valve-Electric Drive Unit) 225 is configured to be able to control the opening degree by applying a driving force to the impulse valve 224. This is an electrically driven actuator as an example of the “driving means” according to the present invention. The IPVEDU 225 includes a drive motor, a motor drive circuit, and a rotation angle sensor (all not shown and reference numerals omitted).

  The drive motor is a DC brushless motor that is connected to the rotary shaft 224B described above and is provided with a permanent magnet and includes a rotor (not shown) as a rotor and a stator as a stator, and a stator via a drive circuit. When the rotor is rotated by the action of a rotating magnetic field formed in the drive motor by energizing the motor, a driving force is generated in the rotation direction.

  The motor drive circuit is a current control circuit including an inverter configured to be able to control a state of a magnetic field formed inside the drive motor through energization of the stator. The motor drive circuit is electrically connected to the ECU 100, and the operation of the motor drive circuit is controlled by the ECU 100. The drive motor is a DC brushless motor, and the drive voltage is a drive voltage Vdc, which is a direct current voltage, but the current supplied to the stator is generated by an inverter in the motor drive circuit, It is a three-phase alternating current corresponding to the v phase and the w phase.

  The rotation angle sensor is a so-called resolver configured to be able to detect the rotation angle of the rotor by utilizing the change of the phase of the voltage output from the two-phase coil of the rotor in the drive motor. As described above, the rotor is connected to the rotation shaft 224B of the impulse valve 224, and the rotor rotation angle ζ detected by the rotation angle sensor is uniquely related to the opening of the impulse valve 224. The rotation angle sensor is electrically connected to the ECU 100, and the detected rotation angle ζ of the rotor is configured to be grasped by the ECU 100 at a constant or indefinite cycle as a physical quantity representing the opening degree of the impulse valve 224. ing. That is, the case where the rotor rotation angle ζ is 0 ° corresponds to the fully closed position CL (full opening degree) of the impulse valve 224, and the case where the rotor rotation angle ζ is 90 ° is the fully open position OP ( (Fully open position). The means for detecting the opening degree of the impulse valve 224 is not limited to the resolver, and may be, for example, a hall sensor, a rotary encoder, or the like.

  The DC / DC converter 226 is a boosting unit that boosts a DC voltage supplied from an unillustrated alternator to a predetermined high voltage. Note that “high voltage” means a voltage higher than a DC 12V battery, which is stored in a low voltage battery as a so-called in-vehicle battery, and is set to a value of about 40V in this embodiment. The DC high voltage boosted by the DC / DC converter 226 is supplied to the IPVEDU 225 as the above-described drive voltage Vdc, and is appropriately supplied to the high voltage battery 227 for high voltage storage.

  Engine 200 includes variable working angle type VVT 228. The variable working angle type VVT 228 is a device configured to be able to continuously change the phase and the working angle of the intake valve 207. The variable working angle type VVT 228 includes a plurality of drive systems such as a vane drive hydraulic actuator and a swing cam drive motor. The drive system is electrically connected to the ECU 100 and its operation state is controlled by the ECU 100. Thus, the operation state is controlled by the ECU 100 to the upper level. The variable working angle type VVT 228 has a known vane type phase variable function using a hydraulic actuator and a known lost motion type working angle (ie, valve lift amount) variable function using a swing cam driven by a motor. It is a device having both.

  In the description of the intake valve 207, it is described that the intake valve 207 has one opening / closing characteristic defined by the cam profile of the intake cam 208. This is because the operation of the variable operating angle VVT 228 is described. The cam profile of the intake cam 208 affects the opening / closing characteristics of the intake valve 207 with respect to one operating state of the variable working angle type VVT 228 (that is, the vane position, the pivot point position of the swing cam, etc.). It means to prescribe.

  In the engine system 10 according to the present embodiment, the engine 200 that is a gasoline engine is employed as an example of the “internal combustion engine” according to the present invention. However, the internal combustion engine according to the present invention refers only to the gasoline engine. Of course, a diesel engine, an engine using an alcohol mixed fuel, or the like may be used. Further, for the purpose of preventing the explanation from being complicated, the engine 200 according to the present embodiment is not equipped with an exhaust gas recirculation device such as an EGR device. It may be. Here, in view of the configuration in which the exhaust gas recirculation device is not mounted, in the engine 200 according to the present embodiment, the intake air sucked into each cylinder 202 through the intake port passes through the intake pipe 204 except for the fuel injected by the injector. It is comprised only by the intake air led through.

  The required load of the engine 200 is determined according to an accelerator opening degree Ta that is an operation amount (that is, an operation amount by a driver) of an accelerator pedal (not shown). The accelerator opening degree Ta is detected by the accelerator opening degree sensor 11 and is grasped at a constant or indefinite period by the ECU 100 electrically connected to the accelerator opening degree sensor 11. In general, the smaller the accelerator opening, the smaller the required load, and the larger the accelerator opening, the larger the required load. Since the magnitude of the required load correlates with the magnitude of the required output, in the engine system 10, the engine required output changes according to the accelerator opening degree Ta.

<Operation of Embodiment>
In engine 200, impulse charge is realized in the execution process of basic control and impulse valve drive control, which will be described later, by ECU 100. Here, the impulse charge is an example of “inertia supercharging” according to the present invention, which generates the pulsation of intake air by opening and closing the impulse valve 224 and improves the charging efficiency of the intake air. become that way. In the present embodiment, the opening degree of the impulse valve 224 is controlled with the fully opened opening degree when the valve is opened and the fully closed opening degree when the valve is closed.

  In realizing the impulse charge, for one cylinder 202 (for example, the first cylinder), before the start of the intake stroke (that is, preferably at the end of the intake stroke of another cylinder (for example, the second cylinder)), or The impulse valve 224 is closed at the beginning of the intake stroke. During the period in which the impulse valve 224 is closed, the internal pressure of the communication pipe 206 becomes negative as the piston of the cylinder 202 descends, and the internal pressure of the intake pipe 204 maintained above atmospheric pressure by atmospheric pressure or supercharging. The pressure difference from the pressure increases. When the impulse valve 224 is opened in a state where the negative pressure is sufficiently formed in the communication pipe 206 in this manner (that is, the valve is opened in a valve opening period after the valve opening timing of the intake valve 207), the intake pipe 204 is opened. And the inside of the corresponding cylinder 202 (that is, the first cylinder in this case) communicate with each other, and the intake air flows into the combustion chamber inside the cylinder 202 at once as the intake air via the impulse valve 224.

  On the other hand, the communication pipe 206 is a so-called open end at the communication part with the combustion chamber, and the positive pressure wave caused by the inflow of the intake air into the combustion chamber is reflected by the combustion chamber, so that the phase is inverted. It becomes a pressure wave. The negative pressure wave reaches the surge tank 223 sequentially through the communication pipe 206 and the impulse valve 224, and reaches the combustion chamber again as a positive pressure wave whose phase is inverted by reflection at the open end at the open hole. When the peak of the positive pressure wave reaches the combustion chamber (or to the intake valve 207) (not necessarily limited to that point in time, but includes that point as long as the charging efficiency of the intake can be improved to some extent) The valve opening timing of the impulse valve 224 may be such that the positive pressure wave reaches the combustion chamber by closing the intake valve 207 or at the timing when the intake valve 207 is closed. By controlling this, the pressure in the combustion chamber rises, and the charging efficiency of the intake air is improved. Impulse charging using the impulse valve 224 is realized in this way.

  Next, details of basic control and impulse valve drive control executed by the ECU 100 will be described.

  First, basic control will be described with reference to FIG. FIG. 3 is a flowchart of basic control.

  In FIG. 3, the ECU 100 acquires the driving conditions of the vehicle (step S101). In the present embodiment, the engine speed Ne and the accelerator opening degree Ta are acquired as the operating conditions. When the engine rotation speed Ne and the accelerator opening degree Ta are acquired, it is determined whether or not the acquired operating condition corresponds to the inertial supercharging region (step S102).

  Here, the impulse charge region will be described with reference to FIG. FIG. 4 is a schematic diagram of the impulse charge region.

  In FIG. 4, the impulse charge region is a region corresponding to the hatched region shown in the two-dimensional coordinate system in which the accelerator opening degree Ta and the engine rotational speed Ne are arranged on the vertical axis and the horizontal axis, respectively. More specifically, it is assumed that the range of engine rotation speeds that can be taken by the engine 200 is not less than the minimum rotation speed NeL (which is the minimum rotation speed at which self-rotation is possible) and not more than the maximum rotation speed NeH (which is a so-called rev limit). When the accelerator opening degree Ta changes from 0% (that is, fully closed) to 100% (that is, fully opened), the impulse charge region has NeL ≦ Ne ≦ Neth (Neth <NeH) and Tath ≦ Ta ≦ 100. Qualitatively speaking, it is a low rotation and high load region.

  The minimum rotational speed NeL is, for example, a value of about 800 rpm, and Neth is a determination reference value that is defined in consideration of the limit of the operation speed of the impulse valve 224, and is a value of about 2000 rpm. Also, Tath is a reference value for the accelerator opening, and is a value that can be used to determine that impulse charging is necessary in terms of required load. In other words, in the low load region less than the reference value Tath, it is not necessary to increase the intake charge amount from the beginning, so that impulse charge is not required.

  Returning to FIG. 2, when the acquired operation condition does not correspond to the impulse charge region (step S <b> 102: NO), the ECU 100 sets an execution flag Fg_ip <b> 1 indicating whether or not to perform the impulse charge to OFF indicating that the impulse charge is unnecessary. The state is set (step S106), and the process returns to step S101.

  On the other hand, when the operating condition corresponds to the impulse charge region (step S102: YES), the ECU 100 calculates an impulse valve opening timing Aop that is the opening timing of the impulse valve 224 (step S103). The impulse valve closing timing Acl, which is the valve closing timing, is calculated (step S104). The impulse valve opening timing Aop and the impulse valve closing timing Acl are preliminarily mapped and stored in the ROM as values associated with the engine rotational speed Ne, and the ECU 100 acquires the operating conditions (valve opening) In determining the timing and the valve closing timing, each timing is calculated by selectively acquiring one value corresponding to only the engine speed Ne). The “calculation” is a concept that preferably includes selectively acquiring one value from the map as described above.

  When the impulse valve opening timing Aop and the impulse valve closing timing Acl are calculated, the ECU 100 sets the execution flag Fg_ip1 described above to an ON state indicating that the impulse charge is necessary (step S105), and performs processing. Returning to step S101, a series of processing is repeated. The basic control is repeatedly executed as a loop process in this way.

  Next, details of the impulse valve drive control will be described with reference to FIG. FIG. 5 is a flowchart of the impulse valve drive control. The impulse valve drive control is a control executed independently of the basic control described above.

  In FIG. 5, the ECU 100 determines whether or not the execution flag Fg_ip1 is in an ON state (step S201). When the execution flag Fg_ip1 is in the OFF state (step S201: NO), the ECU 100 controls the impulse valve 224 to the fully open position (step S203), returns the process to step S201, and repeats a series of processes. If the opening of the impulse valve 224 is already a fully opened opening, the opening of the impulse valve 224 is simply maintained fully opened in step S203.

  On the other hand, when the execution flag Fg_ip1 is in the ON state (step S201: YES), the ECU 100 acquires the crank angle of the engine 200 based on the detection result of the crank angle by a crank position sensor not shown in FIG. Then, it is determined whether or not the acquired crank angle is the impulse valve opening timing Aop described above (step S202). When the crank angle is the impulse valve opening timing Aop (step S202: YES), the ECU 100 executes valve opening control to be described later, and controls the opening / closing state of the impulse valve 224 through control of the operation state of the IPVEDU 225 ( Step S300).

  When the crank angle does not correspond to the valve opening timing in the process according to step S202 (step S202: NO), the ECU 100 further determines whether or not the crank angle corresponds to the impulse valve closing timing Acl described above. (Step S204). When the crank angle corresponds to the impulse valve closing timing Acl (step S204: YES), the ECU 100 executes valve closing control to be described later, and controls the open / close state of the impulse valve 224 through control of the operation state of the IPVEDU 225. (Step S400).

  When the valve opening control according to step S300 or the valve closing control according to step S400 is completed, the process returns to step S201, and a series of processes is repeated. If the crank angle does not correspond to either the impulse valve opening timing Aop or the impulse valve closing timing Acl (step S204: NO), the ECU 100 maintains the opening of the impulse valve 224 at the current opening, The process proceeds to step S201, and a series of processes is repeated.

  Here, the outline of the valve opening control and the valve closing control will be described with reference to FIG. FIG. 6 is a timing chart showing the operation state of the PCVEDU 225 in the execution process of the valve opening control and the valve closing control.

  In FIG. 6, time is taken on the horizontal axis, and on the vertical axis, the rotor rotation angle ζ, the impulse valve opening / closing instruction signal (notation in the figure is “open / close instruction signal”), And a q-axis current Iq of the drive motor (which is equivalent to a drive current Iq described later, and is appropriately expressed as “drive current Iq”).

  Here, as described above, the rotor rotation angle ζ is the rotation angle of the rotor in the drive motor constituting the IPVEDU 225 detected by the rotation angle sensor provided in the IPVEDU 225, and the impulse valve 224 to which the rotor is connected. Is equal to the rotation angle of the valve body 224A. That is, the rotor rotation angle ζ is a physical quantity that defines the opening degree of the impulse valve 224.

  The impulse valve opening / closing instruction signal is a control pulse signal supplied from the ECU 100 to the IPVEDU 225. The impulse valve opening / closing instruction signal is a signal corresponding to the low pressure side LO state closing the impulse valve 224 and the high pressure side HI state opening the impulse valve 224.

  The q-axis current Iq is an example of the “drive current” according to the present invention, and is a dq axis formed by setting the d axis in the direction of the magnetic pole pair of the rotor and the q axis in the direction perpendicular thereto. This is the current set on the model. Depending on the configuration of the rotor, a d-axis current may be employed as the drive current. In the present embodiment, a three-phase current corresponding to the u-phase, v-phase, and w-phase is finally calculated based on the q-axis current Iq, and the stator of the drive motor is energized. That is, in this embodiment, current control based on so-called vector control is employed. The current control mode is not necessarily limited to vector control, and, for example, rectangular wave current control may be employed.

  In FIG. 6, when the impulse valve opening / closing instruction signal changes to the HI state, that is, the state in which the impulse valve 224 is opened at time T1, the IPVEDU 225 changes the q-axis current Iq, which is the drive current of the drive motor, to a predetermined maximum value. It is controlled to a value Iq_max (hereinafter referred to as “maximum current value Iq_max” as appropriate). Here, the maximum current value Iq_max is a maximum value defined in terms of control, and a substantial upper limit value defined by physical, mechanical, mechanical, electrical, or magnetic restrictions of the drive motor. Is different.

  When a three-phase current corresponding to the maximum current value Iq_max is applied to the stator of the drive motor, the drive motor is driven at the highest speed in terms of control, and the rotor rotation angle ζ changes substantially at the highest speed. As a result, ζ1 (0 <ζ1 <90) is reached at time T2. As already described, in the present embodiment, the target value of the rotation angle of the rotor is 90 ° (that is, fully opened) when the impulse valve 224 is opened, and is also 0 ° (when the valve is closed). That is, the fully closed opening).

  Here, ζ1 is a valve-opening side control switching angle that defines the switching timing of the current control mode (which does not change to the point of vector control), and in the angle range below ζ1, the above-described maximum current value Iq_max (Hereinafter, the current control mode is appropriately referred to as “maximum current control”), and in an angle range larger than ζ1, the current rotor rotation angle ζ and the target rotation angle (ie, The feedback control of the drive current Iq is performed based on the deviation from 90 ° or 0 °. The feedback control of the driving current Iq is executed as so-called PID control based on the P term (proportional term), the I term (integral term), and the D term (differential term). It will be referred to as “control”.

  After the rotor rotational angle ζ reaches the valve opening side control switching angle ζ1 at time T2, the PID control is executed, and the rotor rotational angle ζ is quickly and accurately generated at time T3 without causing overshoot. , And converges to the target value (here, 90 °). At this time, during the period in which PID control is executed (hereinafter referred to as “PID control period” as appropriate), the drive current Iq of the drive motor is temporarily reduced to a predetermined minimum value Iq_min (hereinafter referred to as “minimum current value Iq_min” as appropriate). Note that, here, the minimum value is controlled to be reduced to a value that has the same absolute value as the maximum value but a different sign, and gradually increases from the minimum current value Iq_min. The period from the time T1 to the time T2 is an example of the “first period” according to the present invention, and the period from the time T2 to the time T3 (shown hatched area and PID control period) is It is an example of the “second period” according to the invention.

  On the other hand, at time T4 corresponding to the closing timing Acl of the impulse valve 224, when the ECU 100 changes the impulse valve opening / closing instruction signal to the LO state, that is, the state in which the impulse valve 224 is closed, the IPVEDU 225 again The drive current Iq of the drive motor is controlled to the maximum current value Iq_max, and the impulse valve 224 is closed at a substantially maximum speed. The rotor rotation angle ζ reaches the valve closing side control switching angle ζ2 (0 <ζ2 <ζ1) at time T5 in the process of closing the impulse valve 224 at the highest speed.

  When the rotor rotation angle ζ reaches the valve closing side control switching angle ζ2, the IPVEDU 225 switches the control mode of the drive current Iq from maximum current control to PID control (target value is 0 °), and the rotor rotation angle ζ is quickly and accurately controlled. In addition, the target value (here, 0 °) is converged without causing overshoot. As a result, at time T6, the rotor rotation angle ζ reaches the target value. The period from the time T5 to the time T6 (shown hatched area) is also an example of the “second period” according to the present invention. At this time, the drive current Iq gradually increases from the minimum current value Iq_min during the PID control period and becomes zero at time T6, as in the valve opening. The valve opening control and the valve closing control in the impulse valve drive control are basically executed in this way. A period from time T1 to time T3 corresponds to a period during which valve opening control is executed, and a period from time T4 to time T6 corresponds to a period during which valve closing control is executed.

  Here, whether the drive voltage Vdc of the IPVEDU 225 is supplied from the DC / DC converter 226 or supplied from the high voltage battery 227 is not always stable, and the power generation state of the alternator and the high voltage battery 227 are not always stable. Depending on the storage state of the battery, it may fluctuate. In particular, when the drive voltage Vdc is not within a predetermined design voltage or a predetermined range including the design voltage, the inductance of the stator when the drive motor is energized changes from the design value. When this type of situation occurs due to a change in the rise characteristic, particularly when the drive voltage Vdc decreases, the rise of the drive current Iq becomes slow.

  At this time, since the driving energy of the rotor becomes insufficient, for example, the rotational speed of the rotor at the valve opening side control switching angle ζ1 (the same applies to the valve closing side control switching angle ζ2) deviates from the design range, and PID control is performed. It does not necessarily work effectively. Therefore, as a result, it is difficult to converge the rotor rotation angle ζ to the target value, the valve opening control and the valve closing control become substantially impossible to execute, and the impulse charge may be impossible. In some cases, the impulse valve 224 becomes uncontrollable at the fully closed position CL, which may cause engine stall, deterioration of emissions, and the like.

  Therefore, in the present embodiment, in the valve opening control and the valve closing control that are selectively executed during the execution process of the impulse valve drive control, the impulse valve 224 is changed when the drive voltage Vdc of this type changes (particularly, when it decreases). Controllability is suitably secured.

  Here, the details of the valve opening control will be described with reference to FIG. FIG. 7 is a flowchart of the valve opening control.

  In FIG. 7, the ECU 100 acquires the value of the drive voltage Vdc of the IPVEDU 225 supplied from the DC / DC converter 226 or the high voltage battery 227 as described above (step S301). Here, the drive voltage Vdc is repeatedly monitored by the ECU 100 via the IPVEDU 225 at a constant or indefinite period, and a special processing step such as detecting or estimating the drive voltage Vdc is not required.

  When the drive voltage Vdc is acquired, the ECU 100 acquires the rotor rotation angle ζ based on the output result of the rotation angle sensor described above (step S302). By the processing according to step S302, an example of the operation of the specifying means of “specifying the opening of the intake control valve” according to the present invention is realized.

  When acquiring the rotor rotation angle ζ, the ECU 100 calculates the valve opening side control switching angle ζ1 described above (step S303). Here, the characteristics of the valve opening side control switching angle ζ1 will be described with reference to FIG. FIG. 8 is a schematic characteristic diagram conceptually showing the characteristic of the valve opening side control switching angle ζ1.

  In FIG. 8, the vertical axis and the horizontal axis represent the valve opening side control switching angle ζ1 and the drive voltage Vdc, respectively. As shown in the figure, the valve opening side control switching angle ζ1 increases the drive voltage Vdc. It is set as an increasing function that increases. For example, the valve-opening side control switching angle ζ1 is ζ10 with respect to the drive voltage Vdc0 (hereinafter referred to as “reference drive voltage Vdc0” as appropriate) as the design value adapted in advance, which is less than the reference drive voltage Vdc0. With respect to the drive voltage Vdc1, the valve opening side control switching angle ζ1 is ζ11 less than ζ10. The ROM of the ECU 100 stores a valve opening side control switching angle map that numerically represents the relationship corresponding to FIG.

  Returning to FIG. 7, in the processing according to step S <b> 303, the ECU 100 refers to the valve-opening side control switching angle map stored in the ROM and sets one value corresponding to the acquired drive voltage Vdc to the valve-opening side control switching. By setting as the angle ζ1, the valve opening side control switching angle ζ1 is calculated.

  When the valve opening side control switching angle ζ1 is calculated, the ECU 100 determines whether or not the current rotor rotation angle ζ is less than the valve opening side control switching angle ζ1 (step S304). When the rotor rotation angle ζ is less than the valve opening side control switching angle ζ1 (step S304: YES), that is, in FIG. 6, when the time is between T1 and T2, the ECU 100 drives the drive motor. The current Iq is set to the maximum current value Iq_max (step S305).

  Subsequently, the ECU 100 converts the coordinate system from the coordinate system based on the rotor (that is, the coordinate system defined by the q axis and the d axis) to the fixed coordinate system (two phases α and β) based on the stator. Is executed (step S306). Further, the ECU 100 executes a phase conversion process from two phases to three phases, and calculates three-phase currents Iu, Iv, and Iw applied to the stator (step S307). When the three-phase current is calculated, the ECU 100 controls the IPVEDU 225 so that the three-phase current is applied to the stator, and executes energization processing (step S308). As a result, the above-described maximum current control is realized, and the rotor of the drive motor is substantially driven at the highest speed.

  When the energization process according to step S308 ends, the process returns to step S304, and the maximum current control is continued until the rotor rotation angle ζ reaches the valve opening side control switching angle ζ1. On the other hand, when the rotor rotation angle ζ is not less than the valve opening side control switching angle ζ1 (step S304: YES), the PID control period described in FIG. 6 is entered, and the ECU 100 determines the rotor rotation angle ζ and the rotor of the drive current Iq. PID control based on the deviation from the target value (90 °) of the rotation angle is started. First, the ECU 100 calculates a drive current Iq (step S309). The PID control may be performed in a known manner based on the proportional gain Kp, the integral gain Ki, and the differential gain Kd, and details thereof will be omitted here.

  When the drive current Iq is calculated, the ECU 100 performs the energization process through the fixed axis conversion (step S310) process and the three-phase conversion process (step S311), as in the process of steps S306 to S308 described above. Execute (step S312). As a result, the absolute value of the drive current Iq starts to gradually decrease.

  The ECU 100 determines whether or not the rotor rotation angle ζ has reached the target value of 90 ° (step S313). If the rotor rotation angle ζ is still in the range of ζ1 or more and less than 90 ° (step S313: NO), the process returns to step S309, and a series of processes is repeated. That is, the PID control period is continued. When the rotor rotation angle ζ converges to the target value of 90 ° (step S313: YES), the valve opening control ends.

  Next, details of the valve closing control will be described with reference to FIG. FIG. 9 is a flowchart of the valve closing control. In the figure, the same parts as those in FIG. 7 are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

  In FIG. 9, when the rotor rotation angle ζ is acquired in the processing according to step S302, the ECU 100 calculates the valve closing side control switching angle ζ2 (step S401). Here, the characteristics of the valve closing side control switching angle ζ2 will be described with reference to FIG. FIG. 10 is a schematic characteristic diagram conceptually showing the characteristic of the valve closing side control switching angle ζ2.

  In FIG. 10, the vertical axis and the horizontal axis represent the valve closing side control switching angle ζ2 and the drive voltage Vdc, respectively. As illustrated, the valve closing side control switching angle ζ2 increases the drive voltage Vdc. It is set as a decreasing function that decreases. For example, the valve closing side control switching angle ζ2 is ζ20 with respect to the reference driving voltage Vdc0 described above, and the valve closing side control switching angle ζ2 is ζ21 larger than ζ20 with respect to the driving voltage Vdc1 less than the reference driving voltage Vdc0. is there. The ROM of the ECU 100 stores a valve closing side control switching angle map that numerically represents the relationship corresponding to FIG.

  Returning to FIG. 9, in the process according to step S <b> 401, the ECU 100 refers to the valve closing side control switching angle map stored in the ROM, and sets the one value corresponding to the acquired drive voltage Vdc to the valve closing side control switching. By setting as the angle ζ2, the valve closing side control switching angle ζ2 is calculated.

  When the valve closing side control switching angle ζ2 is calculated, the ECU 100 determines whether or not the current rotor rotation angle ζ is larger than the valve closing side control switching angle ζ2 (step S402). When the rotor rotation angle ζ is larger than the valve closing side control switching angle ζ2 (step S402: YES), the maximum current control according to steps S305 to S308 is executed, and the rotor rotation angle ζ is equal to or smaller than the valve closing side control switching angle ζ2. (Step S402: NO), the PID control according to Steps S309 to S312 is executed.

  The ECU 100 determines whether or not the rotor rotation angle ζ has reached the target value of 0 ° during the valve closing side PID control period (step S403). When the rotor rotation angle ζ has not yet converged to the target value of 0 ° (step S403: NO), the process is returned to step S309, a series of processes relating to PID control is repeated, and the rotor rotation angle ζ is the target value. (Step S403: YES), the valve closing control ends.

  Here, in order to explain the effect of the present embodiment, referring to FIG. 6 again, according to the above-described valve opening control and valve closing control, the drive voltage Vdc is compared with the reference voltage Vdc0 (in practice, the reference voltage). When it decreases, the valve opening side control switching angle ζ1 changes to the decreasing side, and the valve closing side control switching angle ζ2 changes to the increasing side. This means that the current control mode shifts to PID control earlier in both the valve opening control and the valve closing control.

  When the drive voltage Vdc decreases, the PID control becomes difficult to function effectively. However, since the PID control is started at an early stage in this way, the rotor rotation angle is reduced even when the drive voltage Vdc is decreased. It is possible to converge to the target value. That is, the convergence of the impulse valve 224 is ensured.

  In the impulse valve drive control, if the execution flag Fg_ip is in the ON state, the impulse valve 224 is repeatedly opened and closed between the fully open position and the fully closed position mainly in the intake stroke of each cylinder. Therefore, the opening of the impulse valve 224 needs to converge to the target value within a predetermined period, but no measures are taken against the decrease of the drive voltage Vdc, and the convergence is left lowered. Then, for example, the next operation timing (for example, valve opening timing or valve closing timing) occurs before the opening of the impulse valve 224 converges to the target value. There is a high possibility that the impulse valve 224 falls into an uncontrollable state because the opening degree deviates from a design range (for example, a range with 0 ° to 90 ° or an appropriate margin). That is, in the impulse valve drive control, unlike general valve control (that is, control that the opening only needs to converge to the target value aside from the length of the transition time), the convergence property that suitably includes the transition time and the like. It is necessary to suppress the decrease in the amount as much as possible.

  In that respect, according to the present embodiment, a lot of time is spent by the PID control, and the transition time required for the rotor rotation angle ζ to converge to the target value after the impulse valve opening / closing instruction signal is switched is the drive voltage Vdc. Although it becomes longer compared to the case where it is at the reference voltage Vdc, at least it becomes shorter than the case where no measures are taken against the decrease in the drive voltage Vdc. That is, according to the present embodiment, it is possible to suitably avoid a situation in which the impulse valve 224 falls into an uncontrollable state.

  Note that, supplementarily, the valve opening side control switching angle ζ1 and the valve closing side control switching angle ζ2 are examples of “control parameters” according to the present invention that define the convergence of the impulse valve 224, respectively. As an example of “the direction in which the decrease in convergence is suppressed”, the direction is changed to a decrease side and an increase side, respectively (that is, the processes according to step S303 and step S401 are respectively the operations of the “change means” according to the present invention. An example).

In the valve opening control and the valve closing control described above, the ECU 100 improves the intake charging efficiency as much as possible for each vehicle operating condition in advance experimentally, empirically, theoretically, or based on simulation or the like. The IPVEDU 225 is controlled so that the impulse valve 224 opens and closes at an opening / closing timing determined so that the intake air is taken into the cylinder 202 at this time, so that the air-fuel ratio is maintained at a predetermined value. The fuel injection amount is corrected. When correcting the fuel injection amount, the fuel injection amount correction amount mapped in advance in association with the vehicle operating conditions and the opening / closing timing of the impulse valve 224 (related to the improvement in the charging efficiency of intake air by inertia supercharging) The reference fuel injection amount is appropriately increased and corrected. For this reason, when the impulse charge is executed, the emission does not deteriorate.
Second Embodiment
The aspect which ensures the convergence of the impulse valve 224 is not limited to that of the first embodiment. Here, with reference to FIG. 11, the detail of the valve opening control which concerns on 2nd Embodiment of this invention based on such a meaning is demonstrated. FIG. 11 is a flowchart of the valve opening control according to the second embodiment of the present invention. In the figure, the same reference numerals are assigned to the same parts as those in FIG. 7, and the description thereof is omitted as appropriate. In addition, about the valve closing control which concerns on 2nd Embodiment, although omitted for the purpose of preventing complication of explanation, the concept similar to valve opening control is applicable.

  In FIG. 11, when the rotor rotation angle ζ is acquired, the ECU 100 sets the valve opening side control switching angle ζ1 (step S501). However, in step S501, the valve opening side control switching angle ζ1 is a preset fixed value (here, it is assumed that it is ζ10 corresponding to the reference drive voltage Vdc).

  On the other hand, when the rotor rotation angle ζ is larger than the valve opening side control switching angle ζ1 (step S304: NO), the ECU 100 calculates a PID gain related to PID control (step S502).

  Here, the characteristics of the PID gain according to the present embodiment will be described with reference to FIGS. FIG. 12 is a schematic characteristic diagram conceptually showing the characteristic of the proportional gain Kp, and FIG. 13 is a schematic characteristic diagram conceptually showing the characteristic of the integral gain Ki. FIG. 14 is a schematic characteristic diagram conceptually showing the characteristic of the differential gain Kd. In these drawings, the same reference numerals are given to the same portions as those in FIG. 8, and the description thereof will be omitted as appropriate.

  In FIG. 12, the ordinate and the abscissa represent the proportional gain Kp and the drive voltage Vdc, respectively. As illustrated, the proportional gain Kp is set as a decreasing function that decreases with an increase in the drive voltage Vdc. ing. For example, the proportional gain Kp is Kp0 with respect to the reference drive voltage Vdc0, and the proportional gain Kp is Kp1 larger than Kp0 with respect to the drive voltage Vdc1 less than the reference drive voltage Vdc0. The ROM of the ECU 100 stores a proportional gain map that numerically represents the relationship corresponding to FIG.

  In FIG. 13, the vertical axis and the horizontal axis represent the integral gain Ki and the drive voltage Vdc, respectively. As illustrated, the integral gain Ki is set as a decreasing function that decreases with an increase in the drive voltage Vdc. ing. For example, the integral gain Ki is Ki0 with respect to the reference drive voltage Vdc0, and the integral gain Ki is Ki1 larger than Ki0 with respect to the drive voltage Vdc1 less than the reference drive voltage Vdc0. In the ROM of the ECU 100, an integral gain map is previously stored that numerically represents the relationship corresponding to FIG.

  In FIG. 14, the vertical axis and the horizontal axis represent the differential gain Kd and the drive voltage Vdc, respectively. As illustrated, the differential gain Kd is set as a decreasing function that decreases with an increase in the drive voltage Vdc. ing. For example, the differential gain Kd is Kd0 with respect to the reference drive voltage Vdc0, and the differential gain Kd is Kd1 larger than Kd0 with respect to the drive voltage Vdc1 less than the reference drive voltage Vdc0. The ROM of the ECU 100 stores a differential gain map that numerically represents the relationship corresponding to FIG. 14 in advance.

  Returning to FIG. 11, the ECU 100 determines one value corresponding to the drive voltage Vdc from the map corresponding to each of the proportional gain Kp, the integral gain Ki, and the differential gain Kd, and the proportional gain Kp, the integral gain Ki, and the differential gain Kd, respectively. As a result, the calculation of the PID gain according to step S502 is executed. When the calculation of the PID gain is completed, the ECU 100 executes PID control according to steps S309 to S312 based on the calculated PID gain, similarly to the first embodiment.

  According to the present embodiment, when the drive voltage Vdc is decreased, the proportional gain Kp is changed to the increase side, so that the absolute value of the drive current Iq with respect to the deviation between the rotor rotation angle ζ and the target value increases, and the impulse valve 224 driving energy is secured. Similarly, since the integral gain Ki is changed to the increasing side, overshoot due to an increase in the proportional gain Kp is suppressed. Further, the derivative gain Kd is changed to the increasing side, thereby suppressing the convergence from being lowered. For this reason, as in the first embodiment, the convergence of the impulse valve 224 is ensured, and the impulse valve 224 is prevented from falling into an uncontrollable state. At this time, as compared with the first embodiment, the maximum current control is performed regardless of the drive voltage Vdc, so that the transition time is shortened.

  Supplementally, the proportional gain Kp, the integral gain Ki, and the differential gain Kd are other examples of the “control parameter” according to the present invention that defines the convergence of the impulse valve 224, respectively. As an example of “the direction in which the deterioration of the property is suppressed”, each is changed to an increase side (that is, the process according to step S502 is another example of the operation of the “change means” according to the present invention).

<Third Embodiment>
The aspect which ensures the convergence of the impulse valve 224 is not limited to that of the first embodiment and the second embodiment. Here, with reference to FIG. 15, the details of the valve opening control according to the third embodiment of the present invention based on such a purpose will be described. FIG. 15 is a flowchart of the valve opening control according to the third embodiment of the present invention. In the figure, the same reference numerals are given to the same portions as those in FIG. 11, and the description thereof will be omitted as appropriate. In addition, about the valve closing control which concerns on 3rd Embodiment, although omitted for the purpose of preventing complication of explanation, the concept similar to valve opening control is applicable.

  In FIG. 15, when the rotor rotation angle ζ is less than the valve opening side control switching angle ζ1 (step S304: YES), the ECU 100 calculates the maximum current value Iq_max of the drive current Iq (step S601). Here, the characteristics of the maximum current value Iq_max will be described with reference to FIG. FIG. 16 is a schematic characteristic diagram conceptually showing the characteristic of the maximum current value Iq_max. In the figure, the same reference numerals are given to the same portions as those in FIG. 8, and the description thereof will be omitted as appropriate.

  In FIG. 16, the vertical axis and the horizontal axis represent the maximum current value Iq_max and the drive voltage Vdc, respectively. As shown in the figure, the maximum current value Iq_max is expressed as a decreasing function that decreases with an increase in the drive voltage Vdc. Is set. For example, the maximum current value Iq_max is Iq0 with respect to the reference drive voltage Vdc0, and the maximum current value Iq_max is Iq1 larger than Iq0 with respect to the drive voltage Vdc1 less than the reference drive voltage Vdc0. The ROM of ECU 100 stores in advance a maximum current value map that numerically represents the relationship corresponding to FIG.

  Returning to FIG. 15, the ECU 100 executes the calculation of the maximum current value Iq_max according to step S601 by selectively acquiring one value corresponding to the drive voltage Vdc from the maximum current value map. When the calculation of the maximum current value Iq_max is completed, the ECU 100 executes the maximum current control according to steps S305 to S308 based on the calculated maximum current value Iq_max, as in the first embodiment.

  According to the present embodiment, when the drive voltage Vdc is decreased, the maximum current value Iq_max of the drive current Iq is changed to the increase side, so that the shortage of the rotational energy of the rotor due to the decrease of the drive voltage Vdc is compensated for. Compared to the case where Vdc is at the reference drive voltage Vdc0, it is possible to suppress a change in the rotational speed of the rotor when shifting to PID control. Therefore, PID control can function, and it is possible to suppress the influence of the decrease in the drive voltage Vdc on the transition time of the impulse valve 224. That is, a decrease in convergence of the impulse valve 224 is suppressed, and a situation where the impulse valve 224 falls into an uncontrollable state is avoided.

In addition, supplementally, the maximum current value Iq_max is another example of the “control parameter” according to the present invention that defines the convergence of the impulse valve 224, and the “direction in which a decrease in convergence is suppressed according to the present invention”. As an example (ie, the process according to step S601 is another example of the operation of the “change means” according to the present invention).
<Fourth embodiment>
In the first to third embodiments described above, the convergence of the impulse valve 224 is suppressed from being lowered by changing the control parameter of the IPVEDU 225 in the valve opening control and the valve closing control. However, it is possible to avoid a situation in which the impulse valve 224 falls into an uncontrollable state. Here, as a fourth embodiment of the present invention, a fail voltage learning process and a restriction process that are executed by the ECU 100 based on such a purpose will be described. First, details of the fail voltage learning process will be described with reference to FIG. FIG. 17 is a flowchart of the fail voltage learning process. In the figure, the same parts as those in FIG. 7 are denoted by the same reference numerals, and the description thereof is omitted as appropriate. In addition, the structure of the engine system which concerns on 4th Embodiment shall be the same as the engine system 10 which concerns on 1st thru | or 3rd embodiment.

  In FIG. 17, when the rotor rotation angle ζ is acquired, the ECU 100 determines whether the acquired rotor rotation angle ζ is larger than the upper limit value ζmax stored in the ROM in advance or less than the lower limit value ζmin stored in the same manner. It is determined whether or not there is (step S701). Here, the upper limit value ζmax may be a target value on the valve opening side (that is, 90 °), or may be a value obtained by adding a certain margin to the target value. For example, the upper limit value ζmax may be a value around 110 °. Similarly, the lower limit value ζmin may be a target value on the valve closing side (that is, 0 °), but may be a value obtained by adding a certain margin to the target value. For example, the lower limit value ζmin may be a value around −20 °.

  When the rotor rotation angle ζ is within the range defined by the upper and lower limit values (step S701: NO), the process returns to step S301, and a series of processes are repeated, and the rotor rotation angle ζ is increased to the upper limit. If it is greater than value ζmax or less than lower limit value ζmin (step S701: YES), ECU 100 determines whether or not drive voltage Vdc acquired in step S301 is less than reference drive voltage Vdc0 (step S701). S702).

  When the drive voltage Vdc is less than the reference drive voltage Vdc0 (step S702: YES), the ECU 100 sets the drive voltage lower limit value Vdc_low stored in advance in the RAM or flash memory or the like as the value of the current drive voltage Vdc. (Step S703). On the other hand, when the drive voltage Vdc is equal to or higher than the reference drive voltage Vdc0 (step S702: NO), the ECU 100 sets the drive voltage upper limit value Vdc_high that is stored in the appropriate storage means so as to be updatable, as the current drive voltage Vdc value. (Step S704). If the process which concerns on step S703 or step S704 is performed, a process will be returned to step S301 and a series of processes will be repeated.

  Next, details of the restriction process will be described with reference to FIG. FIG. 18 is a flowchart of the restriction process. In the figure, the same reference numerals are assigned to the same parts as those in FIG. 7, and the description thereof is omitted as appropriate. Note that the fail voltage learning process and the limit process are executed independently of each other.

  In FIG. 18, when the drive voltage Vdc is acquired, the ECU 100 acquires the drive voltage upper limit value Vdc_high and the drive voltage lower limit value Vdc_low that are appropriately updated in the previous fail voltage learning process (step S801). Upon acquiring these upper and lower limit values, the ECU 100 further determines whether or not the drive voltage Vdc is greater than the acquired drive voltage lower limit value Vdc_low and less than the acquired drive voltage upper limit value Vdc_high (step S802). ).

  If drive voltage Vdc is within the range defined by these upper and lower limits (step S802: YES), ECU 100 indicates that permission flag Fg_ip2 that defines the permitted state of impulse charge is permitted to perform impulse charge. Is set to the ON state (step S803). On the other hand, when the drive voltage Vdc does not exist within the range defined by these upper and lower limits (step S802: NO), the ECU 100 sets the permission flag Fg_ip2 to an OFF state that prohibits execution of impulse charge. (Step S804). When the setting of the permission flag Fg_ip2 is completed by executing step S803 or step S804, the process returns to step S301, and a series of processes is repeated.

  Here, when the permission flag Fg_ip2 is in the OFF state, the ECU 100 does not execute the impulse charge even if the execution flag Fg_ip1 described above is in the ON state. That is, in the fourth embodiment, immediately after the execution flag Fg_ip1 is referred to in the impulse valve drive control illustrated in FIG. 5, the permission flag Fg_ip2 is referred to, and the permission flag Fg_ip2 is in the OFF state. The process proceeds to step S203. As a result, the impulse valve 224 is maintained at the fully open position. Of course, the correction of the fuel injection amount described above is also stopped.

According to this embodiment, when the opening degree of the impulse valve 224 greatly deviates from the target value in the execution process of the impulse valve drive control (including valve opening control and valve closing control), the drive voltage Vdc of the IPVEDU 225 is Learning is performed by appropriately updating the upper limit drive voltage Vdc_high or the lower limit drive voltage Vdc_low, and when the drive voltage Vdc is not within the permitted range defined by the learned value related to this learning, the opening and closing of the impulse valve 224 is prohibited. . That is, the ECU 100 functions as an example of the “restricting unit” according to the present invention, and an example of the processing that “the operation of the intake control valve is limited” according to the present invention is executed. For this reason, the impulse valve 224 is driven only within a range in which normal operation is guaranteed to some extent, and it is possible to avoid as much as possible the situation of being in an uncontrollable state.
<Fifth Embodiment>
Next, another example of “restricting the operation of the intake control valve” according to the present invention will be described as a fifth embodiment of the present invention with reference to FIG. FIG. 19 is a flowchart of basic control according to the fifth embodiment of the present invention. In the figure, the same reference numerals are given to the same portions as those in FIGS. 3 and 7, and the description thereof is omitted as appropriate.

  In FIG. 19, when the impulse valve opening timing Aop and the impulse valve closing timing Acl are acquired, the ECU 100 acquires the driving voltage Vdc (step S301), and the impulse valve opening timing based on the acquired driving voltage Vdc. Aop is corrected (step S901), and similarly, the impulse valve closing timing Acl is corrected based on the acquired drive voltage Vdc (step S902).

  Here, with reference to FIG. 20 and FIG. 21, the correction | amendment aspect of the impulse valve opening timing Aop and the impulse valve closing timing Acl is demonstrated. FIG. 20 is a schematic characteristic diagram conceptually showing the correction characteristic of the impulse valve opening timing Aop with respect to the drive voltage Vdc. Similarly, FIG. 21 is a schematic characteristic diagram conceptually showing the correction characteristic of the impulse valve closing timing Acl with respect to the drive voltage Vdc. In these drawings, portions overlapping those in FIG. 8 are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

  In FIG. 20, a plurality of characteristics of the impulse valve opening timing Aop with respect to the drive voltage Vdc are set in association with the engine rotational speed Ne (or a group of engine rotational speed Ne). For one engine rotational speed Ne (or Ne group), the engine speed is shifted toward the retarded side (the increased side in the figure) with respect to the decrease in the drive voltage Vdc. Further, as illustrated, the impulse valve opening timing Aop is set on the more advanced side in accordance with the increase in the engine rotational speed Ne.

  On the other hand, in FIG. 21, a plurality of characteristics of the impulse valve closing timing Acl with respect to the drive voltage Vdc are set in association with the engine rotational speed Ne (or a group of the engine rotational speed Ne), and a qualitative tendency As for one engine rotation speed Ne (or Ne group), it is a characteristic that shifts to the advance side (illustration decrease side) with respect to the decrease of the drive voltage Vdc. Further, as shown in the figure, the impulse valve closing timing Acl is set on the more retarded side as the engine rotational speed Ne increases. In FIG. 21, the impulse valve closing timing Acl with respect to the reference drive voltage Vdc0 at one engine rotational speed Ne is Acl0A. Of course, this value is higher than the similar impulse valve opening timing Aop0A in FIG. The value on the retard side.

  Thus, according to the present embodiment, as the drive voltage Vdc decreases, the operating angle on the valve closing side of the impulse valve 224 is changed to the expansion side (that is, “the operation of the intake control valve according to the present invention is restricted). The increase in the transition time of the impulse valve 224 accompanying the decrease in the drive voltage Vdc is alleviated from the influence on the valve opening control or the valve closing control. That is, the situation where the impulse valve 224 falls into an uncontrollable state is avoided as compared with the case where this kind of control is not performed.

  In the one-valve intake system in which the impulse valve 224 is shared by a plurality of cylinders as in the engine 200, it is necessary to repeatedly open and close the impulse valve 224 in the intake strokes of the cylinders adjacent to each other. In order to make impulse charge function effectively, it is necessary to secure a valve operating angle on the valve closing side rather than a valve operating angle on the valve opening side.

  At this time, when correcting the impulse valve opening timing Aop and correcting the impulse valve closing timing Acl with respect to the decrease in the drive voltage Vdc, even if the valve opening timing is corrected according to the characteristics illustrated in FIG. Even if the valve closing timing is corrected in accordance with the characteristics illustrated in Fig. 4, the valve closing side operating angle acts in the direction of expansion. However, as a preferred form, the retarding control of the impulse valve opening timing Aop is the impulse valve closing. It is executed prior to the advance of the valve timing Acl, and the valve closing timing may be maintained as much as possible.

  At this time, when the influence of the increase in the transition time of the impulse valve 224 caused by the decrease in the drive voltage Vdc can be canceled at least in practice by the delay of the impulse valve opening timing Aop, the impulse valve closing timing is not necessarily limited. The advance control of Acl may not be performed. That is, when the impulse valve opening timing Aop alone is not enough to compensate for the effect of the lengthening of the transition time associated with the decrease in the drive voltage Vdc, the advance of the impulse valve closing timing Acl according to the characteristics shown in FIG. Corners may be made. Of course, these may be performed simultaneously.

  Further, in order to reduce the pumping loss in the impulse charge region in advance, the opening timing of the intake valve 207 is delayed (slowly opened), or the closing timing of the intake valve 207 is advanced (early closed). ), The operating angle on the valve opening side of the impulse valve 224 may be sufficiently small. For example, in such a case, the operating angle on the valve opening side may be expanded in order to secure the operating angle on the valve opening side. In any case, the correction of the opening / closing timing of the impulse valve 224 according to the drive voltage Vdc is not limited to the example illustrated here, as long as the impulse valve 224 can be prevented considerably from falling into an uncontrollable state. You may have.

  Here, the state in which the drive voltage Vdc has decreased below the reference drive voltage Vdc0 has been described, but when the drive voltage Vdc is greater than the reference drive voltage Vdc0 for some reason, the transition time of the impulse valve 224 is Therefore, the operating angle on the valve opening side or the operating angle on the valve closing side may be reduced to a value at which the power performance or environmental performance of the engine 200 can be improved to a practically significant level.

  In the case of an engine having a multi-valve intake system having a plurality of impulse valves 224, which is different from the one-valve intake system such as the engine 200, the correction of the impulse valve opening timing Aop and the impulse valve closing timing Acl is corrected. The embodiment may be different from the single valve type.

  Here, referring to FIGS. 22 and 23, as a modification of the present embodiment, the impulse valve opening timing Aop and the impulse for a multi-valve engine (for example, a 4-cylinder 2-valve system or a 4-cylinder 4-valve system). A correction mode of the valve closing timing Acl will be described. FIG. 22 is a schematic characteristic diagram conceptually showing another correction characteristic of the impulse valve opening timing Aop with respect to the drive voltage Vdc. Similarly, FIG. 23 is a schematic characteristic diagram conceptually showing another correction characteristic of the impulse valve closing timing Acl with respect to the drive voltage Vdc. In these drawings, portions overlapping those in FIGS. 20 and 21 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  In FIG. 22, a plurality of characteristics of the impulse valve opening timing Aop with respect to the drive voltage Vdc are set in association with the engine rotational speed Ne (or a group of the engine rotational speed Ne). As a qualitative tendency, For one engine rotation speed (or group), the characteristics shift toward the advance side with respect to the decrease in the drive voltage Vdc. Further, as illustrated, the impulse valve opening timing Aop is set on the more advanced side in accordance with the increase in the engine rotational speed Ne.

  On the other hand, in FIG. 23, a plurality of characteristics of the impulse valve closing timing Acl with respect to the drive voltage Vdc are set in association with the engine rotational speed Ne (or a group of the engine rotational speed Ne), and a qualitative tendency As for the one engine rotation speed Ne, the characteristic shifts to the retard side with respect to the decrease of the drive voltage Vdc. Further, as shown in the figure, the impulse valve closing timing Acl is set on the more retarded side as the engine rotational speed Ne increases. In FIG. 23, the impulse valve closing timing Acl with respect to the reference drive voltage Vdc0 at one engine rotational speed Ne is Acl0B. Of course, this value is more than the same impulse valve opening timing Aop0B in FIG. The value on the retard side.

  As shown in FIGS. 22 and 23, in an engine having a multi-valve intake system, restrictions on the closing timing of the impulse valve are significantly less than in the case of the single valve type (that is, the open / close state of the impulse valve is less). The degree of influence on the intake stroke of other cylinders is small), and the operating angle on the valve opening side of the impulse valve is corrected to the expansion side in order to compensate for the effect of the longer transition time of the impulse valve due to the decrease in the drive voltage Vdc. Is done.

  At this time, as a preferred embodiment, the advance control of the impulse valve opening timing Aop may be executed prior to the delay of the impulse valve closing timing Acl, and the valve closing timing may be maintained as much as possible. At this time, when the influence of the increase in the transition time of the impulse valve 224 caused by the decrease in the drive voltage Vdc can be canceled at least practically by the advance angle of the impulse valve opening timing Aop, the impulse valve closing timing is not necessarily limited. Acl retardation control may not be performed. That is, when the influence of the lengthening of the transition time due to the decrease in the drive voltage Vdc cannot be compensated only by the advance angle of the impulse valve opening timing Aop, the impulse valve closing timing Acl is delayed according to the characteristics shown in FIG. Corners may be made. Of course, these may be performed simultaneously.

  Although the first, second and third embodiments are the same as the fourth and fifth embodiments in that the impulse valve 224 is prevented from falling into an uncontrollable state, the approach is different. The former suppresses a decrease in convergence of the opening degree of the impulse valve 224, and the latter restricts the operation of the impulse valve 224. These are, of course, incompatible, and can provide higher practical benefits when executed in concert with each other. That is, for example, while performing the control according to at least one of the first, second, and third embodiments (of course, a plurality of them may be combined), the abnormal drive state of the impulse valve 224 (by means of them) ( In a case where an uncontrollable state or a state that may cause it is not avoided (of course, the possibility is extremely low), the operation of the impulse valve 224 is limited by the control according to at least one of the fourth and fifth embodiments. Thus, the ECU 100 may control each part, and in that case, the possibility that the impulse valve 224 falls into an uncontrollable state can be significantly reduced.

  In the various embodiments described above, “greater than” and “less than” can be easily replaced with “more than” and “less than” depending on the setting of the reference value for comparison (of course, it is bidirectional). As long as it is a concept and the overall magnitude relationship is defined, it is not an essential part of the present invention that the reference value is included.

  The present invention is not limited to the above-described embodiments, and can be changed as appropriate without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. The control device is also included in the technical scope of the present invention.

1 is a schematic configuration diagram conceptually showing a configuration of an engine system according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view around an impulse valve in the engine system of FIG. 1. It is a flowchart of the basic control performed in the engine system of FIG. FIG. 4 is a schematic diagram of an impulse charge region referred to in the execution process of the basic control of FIG. 3. It is a flowchart of the impulse valve drive control executed in the engine system of FIG. It is a timing chart showing the operation state of PCVEDU in the execution process of the valve opening control and valve closing control selectively performed in the impulse valve drive control of FIG. 6 is a flowchart of valve opening control selectively executed in the impulse valve drive control of FIG. 5. It is a typical characteristic view showing the valve opening side control switching angle characteristic referred in the valve opening control of FIG. 6 is a flowchart of valve closing control that is selectively executed in the impulse valve drive control of FIG. 5. FIG. 10 is a schematic characteristic diagram conceptually showing characteristics of a valve closing side control switching angle referred to in the valve closing control of FIG. 9. It is a flowchart of the valve opening control which concerns on 2nd Embodiment of this invention. FIG. 12 is a schematic characteristic diagram conceptually showing a characteristic of a proportional gain Kp referred to in the valve opening control of FIG. 11. FIG. 12 is a schematic characteristic diagram conceptually showing a characteristic of an integral gain Ki referred to in the valve opening control of FIG. 11. FIG. 12 is a schematic characteristic diagram conceptually showing the characteristic of a differential gain Kd referred to in the valve opening control of FIG. 11. It is a flowchart of the valve opening control which concerns on 3rd Embodiment of this invention. FIG. 16 is a schematic characteristic diagram conceptually showing a characteristic of a maximum current value Iq_max referred to in the valve opening control of FIG. 15. It is a flowchart of the fail voltage learning process which concerns on 4th Embodiment of this invention. It is a flowchart of the restriction | limiting process which concerns on 4th Embodiment of this invention. It is a flowchart of basic control concerning a 5th embodiment of the present invention. FIG. 20 is a schematic characteristic diagram conceptually showing a correction characteristic of an impulse valve opening timing Aop with respect to a drive voltage Vdc referred to in the basic control of FIG. 19. FIG. 20 is a schematic characteristic diagram conceptually showing a correction characteristic of an impulse valve closing timing Acl with respect to a drive voltage Vdc referred to in the basic control of FIG. 19. FIG. 16 is a schematic characteristic diagram conceptually showing another correction characteristic of the impulse valve opening timing Aop with respect to the drive voltage Vdc according to a modification of the fifth embodiment. FIG. 16 is a schematic characteristic diagram conceptually showing another correction characteristic of the impulse valve closing timing Acl with respect to the drive voltage Vdc according to a modification of the fifth embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Engine system, 100 ... ECU, 200 ... Engine, 202 ... Cylinder, 204 ... Intake pipe, 205 ... Throttle valve, 206 ... Communication pipe, 207 ... Intake valve, 223 ... Surge tank, 224 ... Impulse valve, 224A ... Valve Body, 224B ... rotating shaft, 225 ... IPVEDU.

Claims (4)

A plurality of cylinders, an intake control valve installed in at least one intake passage communicating with the plurality of cylinders, and configured to be able to perform inertial supercharging utilizing a pulsation of intake air by a change in an open / close state accompanying a predetermined open / close control, And an intake control device for an internal combustion engine comprising drive means capable of applying a drive force used to change the open / close state to the intake control valve,
Specifying means for specifying the opening of the intake control valve;
In the opening / closing control, based on the specified opening and a predetermined type of control parameter, control means for controlling the drive means so that the opening of the intake control valve converges to a target value;
Changing means for changing the control parameter in a direction in which a decrease in convergence when the opening of the intake control valve is converged to the target value is suppressed according to the degree of decrease in the drive voltage in the drive means. An intake control device for an internal combustion engine, comprising: The control means maintains the driving current of the driving means at a predetermined maximum value in a first period until the specified opening degree reaches a predetermined threshold value, and the second time after the threshold value is reached. The opening of the intake control valve is converged to the target value by performing PID control of the drive current based on the specified opening in the period,
2. The intake of the internal combustion engine according to claim 1, wherein the change unit changes at least one of the threshold value, a PID gain related to the PID control, and a maximum value of the drive current as the control parameter. Control device. A plurality of cylinders, an intake control valve installed in at least one intake passage communicating with the plurality of cylinders, and capable of generating an intake pulsation by a change in an open / close state associated with a predetermined open / close control, and the intake control valve An intake control device for an internal combustion engine comprising a driving means capable of applying a driving force provided for a change in an open / close state,
Specifying means for specifying the opening of the intake control valve;
In the opening / closing control, based on the specified opening and a predetermined type of control parameter, control means for controlling the drive means so that the opening of the intake control valve converges to a target value;
An intake control device for an internal combustion engine, comprising: restriction means for restricting the operation of the intake control valve in accordance with a degree of decrease in drive voltage in the drive means. The limiting means fixes the intake control valve at an initial position when the drive voltage is not within an operation permission range defined by a predetermined upper and lower limit value, or an operating angle of the intake control valve according to the drive voltage The intake control device for an internal combustion engine according to claim 3, wherein the operation of the intake control valve is limited by changing.

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