JP2009250037A - Control device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly cope with opening-closing abnormality of an intake control valve, in a control device of an internal combustion engine. <P>SOLUTION: This control device 1 of the internal combustion engine has an intake passage (204 and 206) for introducing intake air to a cylinder, an intake control valve 224 arranged in the intake passage and capable of generating pulsation of a flow of the intake air in response to an opening-closing state, an opening changing means 101 for changing opening of the intake control valve, an output means 100 for outputting an opening-closing indication signal to the intake control valve so as to open or close the valve, a specifying means (such as 100 and 206s) for specifying the possibility of causing opening-closing abnormality of the intake control valve or causing the opening-closing abnormality, and a control means 100 for controlling the opening changing means so as to set the opening of the intake control valve in predetermined opening in addition to controlling the output means so as to output the opening-closing indication signal in the predetermined timing when the occurrence or the occurrence possibility is specified. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technical field of a control device for an internal combustion engine that controls an intake air flow rate.

  As this type of apparatus, for example, an apparatus having an intake control valve for controlling an intake flow rate such as an impulse valve, that is, a so-called pulse supercharging valve has been proposed. According to the intake control valve of the internal combustion engine, in the low speed region of the internal combustion engine, the opening timing of the intake control valve is delayed from the opening timing of the intake valve of each cylinder, and the closing timing of the intake control valve is set to the closing timing of the intake valve. By making it earlier than the timing, it is said that the backflow of the exhaust gas to the intake air during the valve overlap period can be prevented, the introduction of the intake air can be promoted, and the blow back of the intake air can be suppressed.

  In Patent Document 1, a closing angle of the intake control valve is detected by a rotation angle sensor provided in an intake passage provided upstream of the intake valve of the cylinder, and the intake control valve is opened and closed. An apparatus for determining an abnormality is disclosed.

  Also, a method for detecting the pressure in the intake manifold and determining the opening / closing abnormality of the pulse supercharging valve based on the deviation between the pressure value predicted during normal operation of the intake control valve and the actually measured pressure value Has also been proposed.

  Further, in Patent Document 2, the valve body is opened and closed by detecting that the intake negative pressure or the actual measured value of the engine speed is far from the predicted value due to the abnormality of the valve body (variable intake valve body) installed in the intake system. A method for determining an abnormality is disclosed.

  Further, in Patent Document 3, even when it is determined that an abnormality in the opening / closing of the throttle valve has occurred, a technique for handling an instantaneous abnormality due to electrical noise or the like by forcibly driving the throttle valve to open / close is disclosed. It is disclosed.

  Patent Document 4 discloses a technique for dealing with an abnormality caused by electrical noise in a throttle valve opening sensor.

  Patent Document 5 discloses a method of controlling the intake air flow rate with the other rotary valve when one of the two rotary valves fails.

JP-A-3-229946 JP 2005-248825 A JP 2001-303976 A JP 2005-337 211 A Japanese Patent Laid-Open No. 11-324687

  However, according to the above-mentioned Patent Document 1 and the like, when the intake control valve is opened and closed at high speed in order to impulse charge (pulse supercharging), the calculation process cannot be performed in time only by the engine ECU. A dedicated EDU (Electrical Driving Unit) is required, and noise is mixed in the opening / closing instruction signal output from the engine ECU to the EDU, so the opening / closing instruction signal itself is erroneously determined by the EDU, and the intake control valve is not expected There is a technical problem that there is a possibility of performing the operation.

  Further, in Patent Document 5 described above, when an abnormality occurs in which one of the two rotary valves is fully closed, the engine stall is generated because the engine stall cannot be avoided with only one normal valve. There are some problems. This is because two rotary valves are arranged in series, so that if one of the valves is fully closed, the necessary fresh air will not enter the cylinder and the engine will stall. . Further, in Patent Document 5 described above, there is a technical problem that it is not possible to return to a normal opening / closing drive from a malfunction caused by electrical noise. This is because, if an abnormality occurs in which the valve is fully closed due to malfunction due to electrical noise, it is regarded as a failure and the valve is not restored from malfunction.

  Accordingly, the present invention has been made in view of the above-mentioned problems, for example, and an object of the present invention is to provide a control device for an internal combustion engine that can appropriately cope with an abnormal opening / closing of the intake control valve.

  In order to solve the above problems, an internal combustion engine control apparatus according to the present invention is provided in an intake passage for guiding intake air to a cylinder and the intake passage, and generates pulsation of the intake air flow according to an open / close state. Possible intake control valve, opening degree changing means for changing the opening degree of the intake control valve, output means for outputting an opening / closing instruction signal for instructing the intake control valve to open or close, and the intake air The specifying means for specifying the occurrence of the opening / closing abnormality of the control valve or the occurrence possibility of the opening / closing abnormality, and the opening / closing instruction signal is output at a predetermined timing when the occurrence or the occurrence possibility is specified. In addition to controlling the output means, a control means is provided for controlling the opening degree changing means so that the opening degree of the intake control valve is set to a predetermined opening degree.

  An “internal combustion engine” according to the present invention has one or a plurality of cylinders, and in each combustion chamber, a fuel such as gasoline, light oil or various alcohols, or an air-fuel mixture containing the fuel explodes or It is a concept that encompasses an engine that is configured to be able to extract the force generated upon combustion as a driving force through a physical or mechanical transmission path such as a piston, a connecting rod, and a crankshaft. Typically, it refers to a 2-cycle or 4-cycle reciprocating engine.

  The internal combustion engine according to the present invention includes an intake passage for guiding intake air to the cylinder. The intake control valve is provided in the intake passage, and can generate pulsation of the air flow in accordance with opening and closing of the valve. This intake control valve is typically capable of generating at least pulsation of intake air including intake air guided from the outside world according to its open / closed state regardless of whether it is binary, stepwise, or continuous. Alternatively, it is means having a form of a valve operating mechanism or a valve operating apparatus or the like appropriately including a drive device for driving the valve body in addition to the valve body. Here, “intake” according to the present invention refers to gas sucked into a cylinder, and as a preferred form, is intake air itself, for example, when an exhaust gas recirculation device such as an EGR device is provided. May optionally be a mixture of EGR gas (ie exhaust) and intake air.

  According to the control apparatus for an internal combustion engine of the present invention, the opening degree of the intake control valve is changed by the opening degree changing means. The output means outputs an open / close instruction signal that instructs the intake control valve to open or close. By the specifying means, the occurrence of the opening / closing abnormality of the intake control valve or the possibility of occurrence of the opening / closing abnormality is specified. Here, the occurrence of the opening / closing abnormality according to the present invention means that an unintended opening / closing operation of the intake control valve has occurred due to some other cause than the intended opening / closing operation of the intake control valve for output control of the internal combustion engine. means. Typically, when electrical noise is superimposed on the above-described opening / closing instruction signal, it means that the intake control valve has performed an unintended opening / closing operation from the viewpoint of output control of the internal combustion engine. Or, typically, by canceling a part or all of the above-described opening / closing instruction signal, it means that the intake control valve has performed an unintended opening / closing operation in terms of output control of the internal combustion engine.

  Further, the possibility of occurrence of an abnormal opening / closing of the intake control valve according to the present invention means that the possibility or probability of occurrence of the abnormal opening / closing of the intake control valve described above is higher than a predetermined level. This predetermined level is typically not caused by the operating state of electrical auxiliary equipment that directly or indirectly assists the operation of the internal combustion engine, and the possibility or probability that an intake control valve opening / closing abnormality will occur. May mean. This predetermined level is based on theoretical, experimental, empirical, simulation, etc., the possibility and probability of occurrence of abnormalities in opening / closing of the intake control valve in an environment where some or all of the operations of the auxiliary machinery are stopped. It can be obtained by seeking.

  In addition, “specific” according to the present invention typically refers directly or indirectly to the timing at which an opening / closing abnormality occurs or the degree of opening / closing abnormality from the range of some physical quantity or parameter indicating the opening / closing abnormality of the intake control valve. It means "specific", "estimate", etc. In addition to or instead of this, the specification according to the present invention refers to “detecting the timing at which an opening / closing abnormality occurs and the degree of the opening / closing abnormality directly or indirectly from the range of some physical quantity or parameter indicating the opening / closing abnormality described above. "" Detection "" Measurement "means.

  In particular, when the occurrence of an opening / closing abnormality of the intake control valve or the possibility of the occurrence of an opening / closing abnormality is specified, in addition to outputting an opening / closing instruction signal at a predetermined timing by the output means under the control of the control means The opening degree of the intake control valve is set to a predetermined opening degree by the opening degree changing means.

  Here, the predetermined timing according to the present invention means the opening timing or closing timing of the intake control valve whose main purpose is to avoid the abnormal opening and closing of the intake control valve. The timing that can be defined with reference to the top dead center or the bottom dead center, that is, the so-called crank cycle. This predetermined timing is different from the timing for opening and closing the intake control valve for controlling the output torque of the internal combustion engine or controlling the engine speed of the internal combustion engine. However, this predetermined timing may have a secondary purpose of controlling the output torque of the internal combustion engine or controlling the engine speed of the internal combustion engine while mainly aiming at avoiding abnormal opening and closing of the intake control valve.

  In addition, the predetermined opening according to the present invention means the opening of the intake control valve whose main purpose is to avoid the abnormal opening and closing of the intake control valve, and is typically a fully opened opening or a fully opened opening. It means an opening with a small load of opening control such as a closing opening. This predetermined opening degree is different from the opening degree of the intake control valve for controlling the output torque of the internal combustion engine or controlling the engine speed of the internal combustion engine.

  Thereby, even when the intake control valve opening / closing abnormality occurs, it is possible to remarkably reduce the frequency and the degree of malfunction of the intake control valve opening / closing intended for output control of the internal combustion engine. Alternatively, the possibility of occurrence of an abnormal opening / closing of the intake control valve is specified in advance, thereby effectively preventing malfunction of the opening / closing of the intake control valve intended for output control of the internal combustion engine. Can be prevented.

  As a result, due to a malfunction in opening and closing of the intake control valve, the intended intake air pulsation is no longer generated, the output torque of the internal combustion engine is significantly reduced, or the amount of intake air into the cylinder is significantly small. It is possible to appropriately and effectively prevent the engine stall from occurring.

  In one aspect of the control device for an internal combustion engine according to the present invention, the control device further includes an electric system that directly or indirectly assists the operation of the internal combustion engine, and the specifying unit is a start state in which an operation of the electric system is started. And when the operation of the electric system stops from one state to the other state, the occurrence of the opening / closing abnormality or the possibility of occurrence is specified, and the electric system is in the one state or the other When the state is maintained, the occurrence or the possibility of occurrence is not specified.

  According to this aspect, by identifying the start state, the stop state, and the transition between the two states in the electrical system, the occurrence possibility of the occurrence of the intake control valve opening / closing abnormality or the intake control valve opening / closing abnormality can be simplified and simplified. Can be identified appropriately. The electric system typically means an electric device including an auxiliary machine of an internal combustion engine, an electric motor, a generator, etc. that gives electric noise to an opening / closing instruction signal.

  In another aspect of the control device for an internal combustion engine according to the present invention, the control device further comprises detection means for detecting the pressure in the intake passage, and measurement means for measuring the engine speed of the internal combustion engine. Based on the correlation between the detected pressure or the detected rate of change of the pressure and the measured engine speed, the occurrence or possibility of the opening / closing abnormality is specified.

  According to this aspect, the intake control valve opening / closing abnormality or the possibility of occurrence of the intake control valve opening / closing abnormality is hardly or completely irrelevant to the signal control processing of the intake control valve opening / closing instruction signal. It can be specified by the pressure in the passage or the rate of change of the pressure and the engine speed of the internal combustion engine. Here, the rate of change in pressure according to the present invention means the amount of change in pressure per unit time.

  As a result, it is possible to functionally distinguish between the signal control processing of the opening / closing instruction signal and the identification processing of occurrence / occurrence of opening / closing abnormality, so that the output after the occurrence / occurrence of opening / closing abnormality is identified. The opening / closing instruction signal is output at a predetermined timing by the means, and the fail-safe process for causing the opening degree of the intake control valve to be the predetermined opening degree by the opening degree changing means can be quickly and appropriately performed.

  If the above-mentioned fail-safe process is performed via a communication process in which an opening / closing change means identifies an opening / closing abnormality of the intake control valve and notifies the opening / closing abnormality to the control means, the signal control process and the opening / closing abnormality Since the communication process for notifying the control means is performed, the fail-safe process may be delayed.

  In the aspect according to the control means described above, the flow rate detecting means for detecting the flow rate of the intake air is further provided, and the specifying means includes the detected pressure or the rate of change of the detected pressure and the measured engine speed. The occurrence of the opening / closing abnormality or the possibility of occurrence thereof may be specified based on the correlation between the number and the detected flow rate.

  If comprised in this way, generation | occurrence | production of the opening / closing abnormality or the said possibility of generation | occurrence | production can be pinpointed with higher precision using more physical quantities and variable parameters.

  In another aspect of the control apparatus for an internal combustion engine according to the present invention, the control means controls the output means to output the opening / closing instruction signal at a timing synchronized with a crank cycle as the predetermined timing.

  According to this aspect, since the opening / closing instruction signal can be output at a timing synchronized with a crank cycle that can be defined with reference to the top dead center or the bottom dead center of the piston, the load of the output signal processing of the opening / closing instruction signal is reduced, An abnormal opening / closing of the intake control valve can be avoided more quickly.

  In another aspect of the control apparatus for an internal combustion engine according to the present invention, the control means controls the output means so as to output the opening / closing instruction signal at least once within the intake stroke of the cylinder as the predetermined timing. To do.

  According to this aspect, since the opening / closing instruction signal for avoiding the abnormal opening / closing of the intake control valve is output at least once in the intake stroke, the pulsation of the intake flow that can be generated by the intake control valve can be maintained. . Thereby, it is possible to achieve both the avoidance of the opening / closing abnormality of the intake control valve and the control of the output torque of the internal combustion engine or the control of the engine speed of the internal combustion engine.

  In another aspect of the control apparatus for an internal combustion engine according to the present invention, the intake passage is shared by a plurality of cylinders, and one intake control valve is provided in the shared intake passage.

  According to this aspect, typically, at least one of the plurality of cylinders is in the intake stroke, so that a predetermined timing for outputting the opening / closing instruction signal is set in order to avoid an abnormal opening / closing of the intake control valve. The degree of freedom can be increased.

  In another aspect of the control apparatus for an internal combustion engine according to the present invention, the intake passages include a plurality of intake passages for intake air respectively provided in a plurality of cylinders, and the intake control valves include a plurality of intake passages. And a plurality of intake control valves that are respectively provided and can generate the pulsation of the intake air according to the open / closed state.

  According to this aspect, typically, the plurality of intake control valves respectively generate the intake pulsations corresponding to the intake strokes of the plurality of cylinders, and avoid the opening / closing abnormality of the intake control valves. A signal is output. As a result, it is possible to avoid the abnormal opening / closing of the intake control valve individually in all the cylinders of the plurality of cylinders, so control of the total amount of output torque output by each of the plurality of cylinders or control of the engine speed of the internal combustion engine Can be realized.

  The operation and other advantages of the present invention will become apparent from the best mode for carrying out the invention described below.

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

(First embodiment)
(Basic configuration)
First, with reference to FIG. 1, the structure of the engine system 10 which concerns on embodiment of this invention is demonstrated. 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 a “control device for an internal combustion engine”. The ECU 100 is configured to be able to execute various control processes described later according to a control program stored in the ROM. The ECU 100 inputs and outputs various signals with an impulse valve EDU (Electrical Drive Unit) 101 described later, an injector EDU (Electrical Drive Unit) 101 described later, and various sensors.

  The ECU 100 is an integrated electronic control unit that functions as a “control unit” according to the present invention. However, the physical, mechanical, and electrical configurations of these units according to the present invention are limited to this. For example, it may be configured as various computer systems such as a plurality of ECUs, various processing units, various controllers or a microcomputer device.

  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. Then, the air-fuel mixture containing fuel is compressed in the compression stroke in each cylinder, and the force generated when ignited by the ignition operation of the ignition device 203 is applied to a 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. A start motor M for starting the engine is connected to the crankshaft.

  Below, the principal part structure of the engine 200 is demonstrated with a part of the operation | movement. Since the configuration of each cylinder 202 is 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 designated as “first cylinder # 1”, “second cylinder # 2”, “third cylinder # 3”, and “fourth cylinder #”. 4 ”.

  In FIG. 1, intake air that is air guided from the outside is supplied through an intake pipe 204. A surge tank 205 is installed in the intake pipe 204 and communicates with the intake pipe 204 inside. The surge tank 205 is a storage means for stably supplying intake air to the cylinder 202 side. The intake air flowing in the intake pipe 204 is temporarily stored in the surge tank 205, and its irregular pulsation, etc. Is configured to be suppressed.

  On the downstream side of the surge tank 205 (that is, in this case, the cylinder 202 side), the intake pipe 204 communicates with the intake branch pipe 206. The intake branch pipe 206 communicates with each intake port (not shown) of each cylinder 202, and intake air flowing through the intake pipe 204 passes through the intake branch pipe 206 and is not shown corresponding to each cylinder. It is configured to be guided to the port. 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 communication state between the intake port and the cylinder 202 is controlled by an intake valve 207 provided for each intake port. The intake valve 207 is fixed to an intake camshaft (not shown) that rotates in conjunction with the crankshaft, and a cam profile (not shown) of an intake cam (not shown) whose section perpendicular to the extension direction of the intake camshaft is elliptical. 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. As described above, in the engine 200, the intake pipe 204 and the intake branch pipe 206 are shared by the four cylinders 202, which is an example of the “intake passage” according to the present invention.

An injector injection valve (not shown) 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 during 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 is ignited and ignited by the ignition control (which is controlled by the ECU 100) of the ignition device 203 performed in the vicinity of the compression TDC ( That is, it is configured to explode). In particular, the amount and timing of fuel injection by the injector are controlled by an injector EDU (Electrical Drive Unit) 102. In this embodiment, the injector is a so-called electronically controlled port injector, and the fuel is an intake port. However, the fuel injection mode is not limited in any way. For example, instead of or in addition to this type of port injector, fuel can be directly injected into the high-temperature and high-pressure cylinder 202, for example, a common rail system. Alternatively, an in-cylinder direct injection system including a unit injector or the like may be employed.

  The combusted air-fuel mixture or the partially unburned air-fuel mixture is guided to the exhaust manifold 213 as exhaust gas via an exhaust port (not shown) when the exhaust valve 210 that opens and closes in conjunction with opening and closing of the intake valve 207 is opened. It has become. The exhaust valve 210 is fixed to an exhaust camshaft (not shown) that rotates in conjunction with a crankshaft, and a cam profile (not shown) of an exhaust cam (not shown) whose section perpendicular to the extending direction of the exhaust camshaft is elliptical. In short, the opening / closing characteristics are defined according to the shape), and the exhaust port and the inside of 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. The exhaust pipe 214 is provided with a catalyst SH.

  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. In particular, the rotating shaft can be rotated by a supercharger motor 215m. Note that a variable nozzle vane capable of changing the flow rate flowing through the turbine 216 may be provided inside the turbine housing 215.

  The compressor 218 is configured to be able to pump and supply the intake air sucked into the intake pipe 204 from the outside via the air cleaner 219 to the surge tank 205 described above by the pressure accompanying the rotation. The so-called supercharging is realized by the pressure feeding effect of the intake air. 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 a general term for the supercharger including the turbine 216 and the compressor 218 as appropriate.

  Between the air cleaner 219 and the compressor 218, a hot wire type air flow meter 220 capable of detecting the mass flow rate of the intake air is installed. The air flow meter 220 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.

  An intercooler 221 is installed between the compressor 218 and the surge tank 205, and the supercharging efficiency is improved by cooling the supercharged intake air. Further, a throttle valve 222 capable of adjusting the amount of intake air supplied to the surge tank 205 (that is, the intake amount uniquely) is disposed between the intercooler 221 and the surge tank 205. The throttle valve 222 is a rotary valve that is electrically connected to the ECU 100 and is configured to be rotatable by a driving force supplied from a throttle valve motor 223 that is controlled by the ECU 100 at the upper level. The rotational position is continuously controlled from the fully closed position where the upstream and downstream portions of the intake pipe 204 are substantially blocked to the fully opened position where the intake pipe 204 is almost fully communicated. Thus, in the engine 200, the throttle valve 222 and the throttle valve motor 223 constitute a kind of electronically controlled throttle device.

  The throttle opening that is the opening of the throttle valve 222 is controlled according to the accelerator opening that is the amount of operation of an unillustrated accelerator pedal. The accelerator opening is detected by the accelerator opening sensor 11 and is grasped at a constant or indefinite period by the ECU 100 electrically connected to the accelerator opening sensor 11. In general, the smaller the accelerator opening, the smaller the throttle opening (that is, the direction in which the intake air amount is throttled), and the larger the accelerator opening, the larger the throttle opening (ie, reducing the intake air amount). The throttle valve motor 223 is controlled by the ECU 100 in accordance with the detected accelerator opening. In particular, in view of the fact that the throttle opening is an index that affects the intake air amount (that is, the magnitude of the throttle opening corresponds to the magnitude of the intake air amount, respectively) The engine load state is ultimately defined by the accelerator opening.

  On the other hand, an impulse valve 224 is provided between the surge tank 205 and the intake valve 207, more specifically, in the vicinity of a connection portion between the intake pipe 204 and the intake branch pipe 206 communicating with each intake port. The impulse valve 224 is a binary open / closed state of a fully closed state in which communication between the surge tank 205 and the intake branch pipe 206 is blocked, and a fully open state in which the surge tank 205 and the intake branch pipe 206 are communicated almost entirely. The intake air pulsation, so-called impulse charge, can be realized. The impulse valve 224 is an electromagnetic control valve that is an example of the “intake control valve” according to the present invention. A rotational drive system 224m that rotationally drives the impulse valve 224 is electrically connected to an impulse valve EDU (Electrical Drive Unit) 101. The rotational drive system 224m has a rotational angle sensor such as a resolver. The opening / closing timing of the impulse valve 224 is controlled by a drive pulse signal output by the ECU 100. The drive pulse signal constitutes one specific example of the “open / close instruction signal” according to the present invention. In addition, the opening degree of the impulse valve 224 is controlled by the impulse valve EDU. Specifically, under the control of the ECU 100, current control is performed by the impulse valve EDU so that a current corresponding to the rotation angle that determines the opening degree of the impulse valve flows. The value of the current corresponding to the rotation angle of the impulse valve is calculated by the calculation unit provided in the impulse valve EDU.

  Thus, by providing the impulse valve 224 on the downstream side of the throttle valve 222, in the engine 200, whether or not the intake air is supplied to each cylinder 202 is controlled according to the open / close state of the impulse valve 224.

  Since the impulse valve 224 can take such a binary open / close state as described above, for example, by repeating the open / close operation, the intake air supplied from the surge tank 205 can be supplied to the intake branch pipe 206 while pulsating. It is. By changing the length of the intake pipe between the surge tank 205 and the impulse valve 224 and setting it, the generation state of the pulsation of the intake air may be changed. In consideration of the fact that the intake air is an element constituting the intake air and the intake air can be supplied as a pulsating wave, the intake air is also sucked into the cylinder 202 as a pulsating wave. In this embodiment, it can be said that intake air is equal to intake air except that fuel in a sprayed state is mixed.

  Note that the operation of the impulse valve 224 for pulsating the intake air is not limited to the repetition of such an opening / closing operation, and if the pressure on the upstream and downstream of the impulse valve 224 is different, for example, even if the opening / closing operation is performed once, Pulsations are preferably generated.

  In particular, in the present embodiment, a configuration in which one impulse valve is provided in the intake passage will be described, but this is not restrictive. Four impulse valves may be provided in four intake ports respectively provided in the four cylinders described above.

  A part of the intake passage which is downstream of the impulse valve 224 and upstream of the intake branch pipe 206 and the exhaust manifold 213 communicate with each other through an EGR passage 213e. The EGR passage 213e is provided with an EGR cooler 213c and an EGR valve 213v from the upstream side toward the downstream side with reference to the flowing direction of the reflux gas, so-called EGR gas.

  Inside the surge tank 205, a temperature sensor 205s for measuring the temperature of the intake air is provided.

  A pressure sensor 206s that measures the pressure inside the intake passage is provided inside the intake branch pipe 206.

  A crank angle sensor CS for measuring the crank angle is provided.

  A temperature sensor TS for measuring the temperature of engine coolant is provided.

  In addition, the engine system 10 includes, as an electric system, an electric water pump that circulates cooling water that cools the engine, an electric oil pump that circulates engine oil that lubricates the engine, and a vehicle equipped with the engine. An air conditioner (Air Condition) that cools the space where the driver is present, an electric power steering device that assists the driver in operating the steering wheel, and a fan motor that rotates the radiator fan may be included.

(Operating principle)
Next, the operation principle of the control apparatus for an internal combustion engine according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 2 shows a flow of control processing of the ECU that performs overall control of the internal combustion engine according to the first embodiment of the present invention, focusing on a flag indicating whether or not to open and close the impulse valve. It is the shown flowchart. Note that the control process shown in FIG. 2 is repeatedly executed by the ECU 100 at the first predetermined period Time1.

  In particular, in the present embodiment, when the flag information is “ON”, the condition is positive, and when the flag information is “OFF”, the condition is negative.

(Control processing focusing on a flag indicating whether or not to open and close the impulse valve)
As shown in FIG. 2, first, under the control of the ECU 100, the value stored in the variable tw is substituted into the variable tw_0 (step S101). Here, the variable tw means a variable that stores the value of the engine coolant temperature obtained at the current time under the control of the ECU 100. Further, the variable tw_0 means a variable for storing the temperature value of the engine coolant acquired at a time past the predetermined period Time1 from the current time. The acquisition according to the present embodiment means that the measurement is performed by various sensors and is stored in the storage device of the ECU 100.

  Next, under the control of the ECU 100, the temperature of the engine coolant is acquired at the current time and stored in the variable tw (step S102).

  Next, under the control of the ECU 100, the variable tw_0 indicating the temperature of the engine cooling water acquired at a time past the predetermined period Time1 from the current time is the temperature T1 of the engine cooling water that needs to drive the radiator fan. It is determined whether or not the variable tw indicating the temperature of the engine coolant acquired at the current time is equal to or higher than the temperature T1 of the engine coolant that needs to drive the radiator fan. S103). This determination process can determine whether or not there is a need to drive the radiator fan.

  Here, it is determined that the variable tw_0 is smaller than the temperature T1 of the engine coolant that needs to drive the radiator fan, and the variable tw is equal to or higher than the temperature T1 of the engine coolant that needs to drive the radiator fan. (Step S103: Yes), “ON” is substituted into the FAN drive flag, which is flag information indicating that the radiator fan is driven under the control of the ECU 100 (step S104).

  Next, under the control of the ECU 100, “ON” is substituted into an IPV drive flag that is flag information that means that the impulse valve is driven (step S105).

  Next, under the control of the ECU 100, “0” is substituted into an IPV drive counter that is counter information indicating the number of times the impulse valve is driven (step S106). This IPV drive counter is used for setting a predetermined number of times, for example, five times, which the impulse valve needs to open and close.

  On the other hand, as a result of the determination in step S103 described above, the variable tw_0 is not smaller than the temperature T1 of the engine cooling water that needs to drive the radiator fan, or the engine cooling water that the variable tw needs to drive the radiator fan. When it is determined that the temperature is not equal to or higher than the temperature T1 (step S103: Yes), the variable tw_0 indicating the temperature of the engine cooling water acquired at a time past the predetermined period Time1 from the current time is further controlled under the control of the ECU 100. Cooling of the engine in which the variable tw indicating the temperature of the cooling water of the engine, which is larger than the temperature T2 of the cooling water of the engine that needs to stop the radiator fan and acquired at the current time, needs to stop the radiator fan. The water temperature is T2 or less and “ON” is assigned to the FAN drive flag. Whether it has is determined (step S107).

  The temperature T2 of the engine cooling water that needs to stop the radiator fan is typically 94 degrees Celsius, and the temperature T1 of the engine cooling water that needs to drive the radiator fan described above. Less than 97 degrees Celsius, which is a typical example, is preferable because the radiator fan can be driven efficiently and with low power consumption.

  In particular, the driving timing of the radiator fan is determined in addition to or in place of the above-described timing when the temperature of the cooling water of the engine becomes higher than a predetermined value or lower than the predetermined value. You may consider the timing when the load of the system, so-called alter duty, becomes larger than a predetermined value or becomes smaller than a predetermined value.

  As a result of the determination in step S107 described above, the variable tw_0 is larger than the temperature T2 of the engine cooling water that needs to stop the radiator fan, and the variable tw needs to stop the radiator fan. When it is determined that the temperature is equal to or lower than T2 and “ON” is assigned to the FAN drive flag (step S107: Yes), flag information indicating that the radiator fan is driven under the control of the ECU 100. “OFF” is assigned to a certain FAN drive flag (step S108).

  Next, under the control of the ECU 100, “ON” is substituted into an IPV drive flag that is flag information that means that the impulse valve is driven (step S109).

  Next, under the control of the ECU 100, “0” is substituted into an IPV drive counter which is counter information indicating the number of times the impulse valve is driven (step S110).

  On the other hand, as a result of the determination in step S107 described above, the variable tw_0 is not larger than the temperature T2 of the engine coolant that needs to stop the radiator fan or the variable tw needs to stop the radiator fan. If it is determined that the temperature is not lower than the cooling water temperature T2 or that “ON” is not substituted for the FAN drive flag (step S107: No), the flag means that the radiator fan is driven under the control of the ECU 100. “OFF” is assigned to the information FAN drive flag (step S111).

  Next, under the control of the ECU 100, “OFF” is substituted for the IPV drive flag that is flag information that means that the impulse valve is driven (step S112).

  Next, under the control of the ECU 100, “0” is substituted into an IPV drive counter which is counter information indicating the number of times the impulse valve is driven (step S113).

(Control processing focusing on the operation of opening and closing the impulse valve)
Next, referring to FIG. 3, a control process that focuses on the opening and closing operations of the impulse valve, in other words, the fail-safe process of the impulse valve will be described. FIG. 3 is a flowchart showing the flow of control processing of the ECU that performs overall control of the internal combustion engine according to the first embodiment of the present invention, focusing on the opening and closing operations of the impulse valves. The control process shown in FIG. 3 is repeatedly executed by the ECU 100 at the second predetermined cycle Time2. The second predetermined period Time2 is preferably smaller than the first predetermined period Time1 described above.

  As shown in FIG. 3, under the control of the ECU 100, an IPV drive flag that is flag information indicating that the impulse valve is driven is acquired (step S201).

  Next, under the control of the ECU 100, the engine speed, that is, the engine speed is acquired and stored in the variable Ne (step S202).

  Next, under the control of the ECU 100, it is determined whether or not “ON” is substituted for the IPV drive flag and the value of the IPV drive counter is smaller than the threshold Nipv (step S203). Here, the threshold Nipv means the number of times that the impulse valve needs to be opened and closed during the period in which the IPV drive flag is “ON”.

  As a result of the determination in step S203, when “ON” is assigned to the IPV drive flag and it is determined that the value of the IPV drive counter is smaller than the threshold Nipv (step S203: Yes), further, under the control of the ECU 100. Thus, it is determined whether or not the variable Ne is smaller than the threshold value Nemax (step S204). Here, the threshold value Nemax means the maximum value of the engine speed at which the valve can be closed in addition to the opening of the impulse valve within the intake stroke of each cylinder.

  If it is determined that the variable Ne is smaller than the threshold value Nemax (step S204: Yes), the timing for opening the impulse valve is calculated under the control of the ECU 100 (step S205). In particular, the timing of opening the impulse valve is the timing at which the crank angle approaches the TDC (Top Dead Center) rather than the timing at which the effect of the pulsation of the intake air becomes maximum (so-called timing at which the impulse charge becomes full load). It's okay. Thereby, the negative pressure in a cylinder can be reduced and a pumping loss can be reduced.

  Next, the timing for closing the impulse valve is calculated under the control of the ECU 100 (step S206). In particular, the timing for closing the impulse valve may be a timing near the BDC (Bottom Dead Center) in terms of the crank angle. The timing for opening or closing the impulse valve will be described later.

  Next, a drive pulse signal (or instruction signal) for opening the impulse valve is output at a predetermined timing within the intake stroke of each cylinder under the control of the ECU 100, and the impulse valve is opened and the impulse valve is opened. A drive pulse signal for closing the valve is output, and the impulse valve is closed (step S207).

  Next, under the control of the ECU 100, the value of the IPV drive counter is incremented by 1 (step S208).

  On the other hand, as a result of the determination in step S204 described above, when it is not determined that the variable Ne is smaller than the threshold value Nemax, that is, when it is determined that the variable Ne is greater than or equal to the threshold value Nemax (step S204: No), under the control of the ECU 100. The timing for closing the impulse valve is calculated (step S209). In particular, the timing of closing the impulse valve may be, for example, the timing of crank synchronization, in other words, the timing at which the crank angle is BDC.

  Next, under the control of the ECU 100, the pulse width for realizing the minimum operating angle that can actually maintain the open state of the impulse valve corresponding to the variable Ne, that is, the time interval in which the drive pulse signal is at the LOW level. Is calculated (step S210). Specifically, this time interval may be 4 (msec), for example.

  Thus, when it is determined that the variable Ne is greater than or equal to the threshold value Nemax, the calculated operating angle for maintaining the impulse valve open state actually opens the impulse valve, and the impulse valve Therefore, the impulse valve cannot be opened at the calculated valve opening timing.

  For this reason, the closing of the impulse valve is, for example, in synchronization with the crank, in other words, the crank angle is indicated at the timing of BDC, and only the time interval corresponding to the minimum operating angle that can actually maintain the valve opening state of the impulse valve. And may instruct to open the impulse valve.

  In step S209 described above, in addition to the timing for opening the impulse valve being calculated instead of the timing for closing the impulse valve, the timing for opening the impulse valve is, for example, the timing of crank synchronization. In other words, the timing at which the crank angle is TDC may be used.

  Next, under the control of the ECU 100, in the case of a four-cylinder engine, a drive pulse signal for closing the impulse valve is output at a predetermined timing within the intake stroke of the predetermined cylinder, and the impulse corresponding to the variable Ne described above. The impulse valve is opened before the pulse width corresponding to the minimum operating angle that can actually maintain the valve open state (step S211). More specifically, for example, in the case of a single valve type impulse charge having one impulse valve, it is preferable to open each valve in the intake stroke of four cylinders. However, if it is determined that the variable Ne is greater than or equal to the threshold value Nemax, it is difficult in time to open the impulse valve in all four intake strokes. Therefore, the impulse valve is opened and closed within the intake stroke of one cylinder.

  Next, under the control of the ECU 100, the value of the IPV drive counter is incremented by 1 (step S212).

  On the other hand, as a result of the determination in step S203 described above, when it is determined that "ON" is not assigned to the IPV drive flag or the value of the IPV drive counter is not smaller than the threshold value Nipv (step S203: No), The processes in steps S204 to S212 are omitted.

  As a result, the possibility of occurrence of an abnormal opening / closing of the impulse valve is specified in advance or in advance, and the driving pulse signal is caused by noise in the electric system by actively or intentionally opening / closing the impulse valve. It is possible to effectively prevent malfunction of the opening and closing of the intake control valve intended for output control of the internal combustion engine.

  As a result, due to a malfunction in opening and closing of the impulse valve, the intended intake air pulsation is not generated, the output torque of the internal combustion engine is significantly reduced, or the intake amount of air into the cylinder is significantly reduced. It is possible to appropriately and effectively prevent the engine stall.

(Impulse valve opening and closing timing)
Here, the details of the opening / closing control of the impulse valve will be described with reference to FIG. FIG. 4 is a timing chart showing the opening / closing timing of the impulse valve according to the present embodiment.

  In FIG. 4, the horizontal axis represents time, and the vertical axis represents the first cylinder (# 1 shown), the second cylinder (# 2 shown), and the third cylinder (# 3 shown) in order from the top. And the open / close state of the intake valve 207 and the open / close state of the impulse valve 224 in the fourth cylinder (# 4 in the drawing). In engine 200, the operations of intake valve 207 and impulse valve 224 are controlled by the crank angle. Therefore, the crank angle can be handled as a time concept as well as an angle concept. In FIG. 4, it is assumed that the engine speed Ne is constant in order to maintain the relative positional relationship between the elapsed time and the crank angle.

  In FIG. 4, taking the first cylinder # 1 as an example, the times ti10, ti20, ti30, ti40, and ti50 are respectively compression TDC (TDC in the compression stroke and the start time of the expansion stroke), expansion BDC (BDC in the expansion stroke and the start timing of the exhaust stroke), Exhaust TDC (TDC in the exhaust stroke and the start timing of the intake stroke), Intake BDC (BDC in the intake stroke and the compression stroke) And the time corresponding to the compressed TDC.

  In the engine 200, the first cylinder, the third cylinder, the fourth cylinder, and the second cylinder are arranged in this order (the expression is an example, and how the expression is expressed as long as the cylinders in which one stroke is performed before and after are equal) (For example, the order of explosion may be expressed as the order of the fourth cylinder, the second cylinder, the first cylinder, and the third cylinder).

  In the engine 200, the intake valve 207 opens at the exhaust TDC, and closes at an advanced angle side (that is, at the beginning of the compression stroke) from the intake BDC (as such, the cam profile of the intake cam is determined). )

A drive pulse signal for opening or closing the impulse valve shown in the lower part of FIG. 4A is output from the ECU 100 to the impulse valve EDU. That is, the impulse valve EDU receives, for example, a LOW level drive pulse signal having a voltage value of 0 V,
The impulse valve is driven so as to be fully opened. Alternatively, the impulse valve EDU drives the impulse valve so as to be in a fully closed state when, for example, an HI level drive pulse signal having a voltage value of 5 V is input.

  Taking the first cylinder as an example, the impulse valve EDU opens the impulse valve when a LOW-level drive pulse signal is input at time ti31. The impulse valve is fully opened at time ti32. The impulse valve EDU closes the impulse valve when an HI level drive pulse signal is input at time ti40. The impulse valve is fully closed at time ti41.

  As shown in FIG. 4B and as described above, the timing at which the impulse valve is opened is higher than the timing at which the action of the pulsation of intake air becomes maximum (so-called timing at which the impulse charge becomes full load). The timing may approach the TDC (Top Dead Center) at an angle. Thereby, the negative pressure in a cylinder can be reduced and a pumping loss can be reduced. Specifically, in FIG. 4B, a signal for causing the impulse valve EDU to open, for example, a LOW-level drive pulse signal having a voltage value of 0 V, a so-called valve opening trigger, is applied from the time t31 to the TDC. It is input at time t31a.

(Operation principle of the second embodiment)
Next, the operation principle of the control apparatus for an internal combustion engine according to the second embodiment of the present invention will be described with reference to FIGS. FIG. 5 shows a flag indicating whether or not the impulse valve has closed unintentionally, in other words, the impulse control flow of the ECU that performs overall control of the internal combustion engine according to the second embodiment of the present invention. It is the flowchart shown paying attention to the flag which shows whether the valve closing abnormality occurred in the valve. A specific example of the opening / closing abnormality according to the present invention is constituted by the valve closing abnormality. The control process shown in this figure is repeatedly executed by the ECU 100 at a predetermined cycle.

  FIG. 6 is a graph showing the correlation between the predetermined threshold value of the pressure of the intake pipe for detecting the occurrence of the valve closing abnormality according to the second embodiment of the present invention and the engine speed (FIG. 6 (a) and FIG. 6). FIG. 6B). 6A corresponds to the case where the internal combustion engine is a diesel engine, and FIG. 6B corresponds to the case where the internal combustion engine is a gasoline engine. 6 (a) and 6 (b), the solid line indicates the predetermined threshold when the accelerator opening is zero, that is, the accelerator is off, and the dotted line indicates the maximum accelerator opening, A predetermined threshold when the accelerator is on is shown. These graphs show a specific example of a detection method for detecting the occurrence of a valve closing abnormality, which is a specific example of the opening / closing abnormality according to the present invention, based on a comparison between the pressure value of the intake pipe and a predetermined threshold value. .

  In addition, the vertical axis in FIG. 6 indicates the absolute pressure (kPa: kilo pascal) of the intake pipe pressure, and the horizontal axis in FIG. 5 indicates the engine speed Ne (rpm: revolution per minute).

(Control processing focusing on a flag indicating whether or not a valve closing abnormality has occurred in the impulse valve)
As shown in FIG. 5, first, under the control of the ECU 100, the pressure of the intake pipe is acquired and stored in the variable pim (step S301).

  Next, under the control of the ECU 100, the engine speed is acquired and stored in the variable Ne (step S302).

  Next, under the control of the ECU 100, the accelerator opening is acquired and stored in the variable accp (step S303).

  Next, it is determined whether or not the variable accp is zero under the control of the ECU 100 (step S304). Here, when it is determined that the variable accp is zero, that is, when the accelerator is off, in other words, when the accelerator is not depressed (step S304: Yes), FIG. 6A or FIG. ) And the pressure of the intake pipe at the intersection of the solid line and the engine speed Ne is read and stored in a variable Pf_aoff indicating a predetermined threshold (step S305).

  Next, under the control of the ECU 100, the value of the variable Pf_aoff is stored in the variable Pf (step S305).

  On the other hand, if it is not determined that the variable accp is zero as a result of the determination in step S304 described above, that is, if the accelerator is on, in other words, if the accelerator is depressed (step S304: No), FIG. The pressure in the intake pipe at the intersection of the dotted line in a) or FIG. 6B and the engine speed Ne is read and stored in a variable Pf_acon indicating a predetermined threshold value (step S307).

  Next, under the control of the ECU 100, the value of the variable Pf_acon is stored in the variable Pf (step S308).

  Next, under the control of the ECU 100, it is determined whether or not the variable pim indicating the pressure of the intake pipe described above is smaller than the variable Pf indicating a predetermined threshold value (step S309). Here, when the variable pim indicating the pressure of the intake pipe described above is smaller than the variable Pf indicating the predetermined threshold (step S309: Yes), the valve closing abnormality flag indicating that a valve closing abnormality has occurred in the impulse valve is set to “ON”. Is substituted (step S310).

  On the other hand, if the variable pim indicating the pressure of the intake pipe described above is not smaller than the variable Pf indicating the predetermined threshold (No in step S309) as a result of the determination in step S309 described above, a valve closing abnormality has occurred in the impulse valve. "OFF" is substituted into the valve closing abnormality flag indicating (step S311).

(Control processing focusing on the operation of opening and closing the impulse valve)
Next, with reference to FIG. 7, the control processing focused on the opening and closing operations of the impulse valve according to the second embodiment, in other words, the fail-safe processing of the impulse valve will be described. FIG. 7 is a flowchart showing the flow of control processing of the ECU that performs overall control of the internal combustion engine according to the second embodiment of the present invention, focusing on the opening and closing operations of the impulse valves. The control process shown in FIG. 7 is repeatedly executed by the ECU 100 at a predetermined cycle. Further, in the valve opening and closing control processing of the impulse valve according to the second embodiment shown in FIG. 7, the opening and closing of the impulse valve according to the first embodiment shown in FIG. Processes that are substantially the same as the control processes are assigned the same step numbers, and descriptions thereof are omitted as appropriate.

  As shown in FIG. 7, under the control of the ECU 100, a valve closing abnormality flag indicating that a valve closing abnormality has occurred in the impulse valve is acquired (step S401).

  Next, through the above-described step S202, it is determined whether or not “ON” is substituted for the valve closing abnormality flag and the value of the IPV drive counter is smaller than the threshold Nipv under the control of the ECU 100 ( Step S402). Here, when “ON” is substituted for the valve closing abnormality flag and it is determined that the value of the IPV drive counter is smaller than the threshold Nipv (step S402: Yes), the processing of steps S204 to S212 described above is performed. Done.

  On the other hand, as a result of the determination in step S402 described above, when it is determined that "ON" is not substituted for the valve closing abnormality flag or the value of the IPV drive counter is not smaller than the threshold value Nipv (step S402: No), The processes in steps S204 to S212 described above are omitted.

  Thereby, even when the valve closing abnormality of the impulse valve occurs, it is possible to remarkably reduce the frequency and the degree of the malfunction of the opening / closing of the impulse valve intended for the output control of the internal combustion engine.

  In the above-described second embodiment, the detection method for detecting the occurrence of the valve closing abnormality, which is a specific example of the opening / closing abnormality according to the present invention, based on the comparison between the pressure value of the intake pipe and a predetermined threshold has been described. However, instead of the value of the intake pipe pressure, the absolute value of the rate of change of the intake pipe pressure may be used to detect the occurrence of the valve closing abnormality. Here, the rate of change in pressure according to the present embodiment means the amount of change (dPim / dt) in the pressure of the intake pipe per unit time, and a sudden increase in this value can cause an abnormal closing of the impulse valve. May be detected. When detecting the valve closing abnormality of the impulse valve based on the comparison between the measured change rate of the intake pipe pressure and the predetermined threshold, it is preferable to set the predetermined threshold as follows. That is, when the accelerator opening is zero, that is, when the accelerator opening is off, the engine brake is generated. Therefore, the predetermined threshold value may be set smaller than the rate of change of the intake pipe pressure generated by the engine brake. . On the other hand, when the accelerator is on, the predetermined threshold is set larger than the predetermined threshold when the accelerator is off, so that the occurrence of the valve closing abnormality can be detected more quickly. A throttle opening may be used instead of the accelerator opening. Also, when detecting the occurrence of valve closing abnormality using the absolute value of the rate of change of pressure in the intake pipe, different types of predetermined thresholds are set depending on whether the internal combustion engine is a diesel engine or a gasoline engine. The correlation map shown may be used.

  Specifically, when the internal combustion engine is a diesel engine, when adjusting the engine load or operating the engine brake, the intake flow rate adjustment by the throttle valve, that is, the so-called throttle ring is not used so much, and the intake air is not used during normal operation. Since the value of the pipe pressure is relatively large, it is preferable to detect the occurrence of the valve closing abnormality using the pressure of the intake pipe rather than the rate of change of the pressure of the intake pipe.

  On the other hand, when the internal combustion engine is a gasoline engine, throttling is performed when the engine load is adjusted or when the engine brake is operated, so that the pressure value in the intake pipe is relatively small during normal operation. Since the negative pressure of the pipe is large, it is preferable to detect the occurrence of the valve closing abnormality using the rate of change of the pressure of the intake pipe rather than the pressure of the intake pipe. In addition, since the time during which the rate of change in the pressure of the intake pipe becomes smaller than the predetermined threshold after the actual occurrence of the valve closing abnormality is smaller than the time when the pressure in the intake pipe becomes smaller than the predetermined threshold, Can be detected more quickly, and the fail-safe process of the impulse valve can be performed quickly.

  In this way, the detection of the occurrence of valve closing abnormality using the absolute value of the rate of change in the pressure of the intake pipe is more effective than the case where the occurrence of valve closing abnormality is detected using the pressure of the intake pipe. It is possible to detect an abnormal valve closing more quickly. This is because when detecting the occurrence of valve closing abnormalities using the absolute value of the rate of change in the pressure of the intake pipe, the pressure of the intake pipe is used so much that the volume of the intake pipe and the volume of the surge tank are not considered. This is because the time taken for the rate of change of the pressure in the intake pipe to fall below the predetermined threshold is shorter than when detecting the occurrence of valve closing abnormality.

(Operation principle of the third embodiment)
Next, with reference to FIG. 8, the operation principle of the control apparatus for an internal combustion engine according to the third embodiment of the present invention will be described. FIG. 8 shows the flow of control processing of the ECU that performs overall control of the internal combustion engine according to the third embodiment of the present invention, focusing on a flag indicating whether or not a valve closing abnormality has occurred in the impulse valve. It is a flowchart. The control process shown in this figure is repeatedly executed by the ECU 100 at a predetermined cycle.

  As shown in FIG. 8, first, under the control of the ECU 100, the engine speed when the internal combustion engine is idling is acquired and stored in the variable Ne (step S501).

  Next, it is determined whether the value of the variable Ne when the internal combustion engine is idling under the control of the ECU 100 is smaller than the value obtained by subtracting 100 (rpm) from the target idle speed (step S502). ). Note that this target idle speed is typically determined by idling in an environment that causes little or no abnormalities in the closing of the intake control valve by, for example, stopping part or all of the operation of the auxiliary machinery. The rotational speed can be obtained by theoretical, experimental, empirical, or simulation. The constant of 100 rpm indicates a specific example of the allowable range of the target idle speed.

  As a result of the determination in step S502 described above, it is determined that the value of the variable Ne when the internal combustion engine is idling under the control of the ECU 100 is smaller than the value obtained by subtracting 100 (rpm) from the target idle speed. In the case (step S502: Yes), “ON” is substituted into a valve closing abnormality flag indicating that a valve closing abnormality has occurred in the impulse valve (step S503).

  On the other hand, as a result of the determination in step S502 described above, it is determined that the value of the variable Ne when the internal combustion engine is idling under the control of the ECU 100 is smaller than the value obtained by subtracting 100 (rpm) from the target idle speed. If not (Step S502 :: No), “OFF” is substituted into a valve closing abnormality flag indicating that a valve closing abnormality has occurred in the impulse valve (Step S504).

  Thereby, the opening / closing abnormality of the impulse valve can be detected with high accuracy during idle operation.

(Operation principle of the fourth embodiment)
Next, with reference to FIG. 9, the operation principle of the control apparatus for an internal combustion engine according to the fourth embodiment of the present invention will be described. FIG. 9 shows the flow of control processing of the ECU that performs overall control of the internal combustion engine according to the fourth embodiment of the present invention, focusing on a flag indicating whether or not to open and close the impulse valve. It is the shown flowchart. The control process shown in FIG. 9 is repeatedly executed by the ECU 100 at a predetermined cycle.

(Control processing focusing on a flag indicating whether or not to open and close the impulse valve)
As shown in FIG. 9, first, under the control of the ECU 100, the engine speed is acquired and stored in a variable Ne (step S601).

  Next, under the control of the ECU 100, it is determined whether or not the start mode is “0” and the acquired engine speed is smaller than 100 (rpm) (step S602).

  Here, the start mode according to the present embodiment is identification information for identifying the start state of the internal combustion engine defined by the engine speed when starting the internal combustion engine using the start motor and the success or failure of ignition of the engine. It is. Specifically, when the start mode is “1”, this indicates a start state of the internal combustion engine in which the engine speed is less than 100 (rpm) and the engine has not been successfully ignited. When the start mode is “2”, the engine speed is in a range of 100 to 800 (rpm), and the engine ignition is not successful, indicating a start state of the internal combustion engine. When the start mode is “3”, the engine speed is in a range greater than 800 (rpm), and the ignition of the engine indicates a start state of the internal combustion engine that is successful. The start mode is set to “0” as an initial value when an ignition switch by a driver, that is, an ignition switch is turned on.

  Here, when it is determined that the start mode is “0” and the acquired engine speed is smaller than 100 (rpm) (step S602: Yes), the start mode is set to “1” under the control of the ECU 100. Is substituted (step S603).

  Next, “OFF” is substituted into the IPV drive flag, which is flag information indicating that the impulse valve is driven under the control of the ECU 100 (step S604). In other words, in the start state where the engine speed is smaller than 100 (rpm) by the start motor, there is almost no or no occurrence of an abnormal opening / closing of the impulse valve due to noise caused by driving the start motor. “OFF” is substituted, and the fail-safe process of the impulse valve is omitted.

  Next, under the control of the ECU 100, “0” is substituted into an IPV drive counter that is counter information indicating the number of times the impulse valve is driven (step S605).

  On the other hand, if it is determined as a result of the determination in step S602 described above that the start mode is not “0” or the acquired engine speed is not smaller than 100 (rpm) (step S602: No), the ECU 100 further. Under the control, it is determined whether or not the start mode is “1” and the acquired engine speed is smaller than 800 (rpm) (step S606). Here, when it is determined that the start mode is “1” and the acquired engine speed is smaller than 800 (rpm) (step S606: Yes), the start mode is set to “2” under the control of the ECU 100. Is substituted (step S607).

  Next, under the control of the ECU 100, “ON” is substituted for the IPV drive flag, which is flag information indicating that the impulse valve is driven (step S608).

  Next, under the control of the ECU 100, “0” is substituted into an IPV drive counter which is counter information indicating the number of times the impulse valve is driven (step S609).

  On the other hand, when it is determined as a result of the determination in step S606 described above that the start mode is not “1” or the acquired engine speed is not smaller than 800 (rpm) (step S606: No), the ECU 100 further. Under the control, it is determined whether or not the acquired engine speed is greater than 800 (rpm) (step S610). If it is determined that the acquired engine speed is greater than 800 (rpm) (step S610: Yes), “3” is substituted for the start mode under the control of the ECU 100 (step S611).

  Next, “OFF” is substituted into the IPV drive flag, which is flag information indicating that the impulse valve is driven under the control of the ECU 100 (step S612). In other words, in a starting state where the engine speed is greater than 800 (rpm), ignition is successful, driving of the start motor is stopped, and there is almost no occurrence of an abnormal opening / closing of the impulse valve due to noise due to driving of the start motor. Since it is not complete, “OFF” is assigned to the IPV drive flag, and the fail-safe process of the impulse valve is omitted.

  Next, under the control of the ECU 100, “0” is substituted into an IPV drive counter that is counter information indicating the number of times the impulse valve is driven (step S613).

  In the fourth embodiment, the control processing that focuses on the operation of opening and closing the impulse valve, in other words, the fail-safe processing of the impulse valve, is substantially the same as in the first embodiment described above with reference to FIG. Therefore, explanation is omitted.

(Operation Principle of Fifth Embodiment)
Next, with reference to FIG. 10, the operation principle of the control apparatus for an internal combustion engine according to the fifth embodiment of the present invention will be described. FIG. 10 shows the flow of control processing of the ECU that performs overall control of the internal combustion engine according to the fifth embodiment of the present invention, focusing on a flag indicating whether or not to open and close the impulse valve. It is the shown flowchart. The control process shown in FIG. 10 is repeatedly executed by the ECU 100 at a predetermined cycle.

(Control processing focusing on a flag indicating whether or not to open and close the impulse valve)
As shown in FIG. 10, first, under the control of the ECU 100, the value stored in the variable Fac is substituted into the variable Fac_0 (step S701). Here, the variable Fac means flag information indicating whether or not an in-vehicle air conditioner (air condition) is driven at the current time. Further, the variable Fac_0 means flag information indicating whether or not the air conditioner is driven at a time past the predetermined period from the current time.

  Next, under the control of the ECU 100, a variable Fac that is flag information indicating whether or not the air conditioner is being driven at the current time is acquired (step S702).

  Next, under the control of the ECU 100, the variable Fac_0, which is flag information indicating whether or not the air conditioner is driven at a time past a predetermined period from the current time, is “OFF”, and the air conditioner is It is determined whether or not the variable Fac, which is flag information indicating whether or not driving, is “ON” (step S703).

  Here, when it is determined that the variable Fac_0 is “OFF” and the variable Fac is “ON” (step S703: Yes), a flag indicating that the impulse valve is driven under the control of the ECU 100. “ON” is substituted into the IPV drive flag which is information (step S704).

  Next, under the control of the ECU 100, “0” is substituted into an IPV drive counter that is counter information indicating the number of times the impulse valve is driven (step S705).

  On the other hand, when it is determined that the variable Fac_0 is not “OFF” or the variable Fac is not “ON” as a result of the determination in step S703 described above (step S703: No), the current time is further controlled under the control of the ECU 100. The variable Fac_0, which is flag information indicating whether or not the air conditioner is driven at a past time for a predetermined period, is “ON”, and is flag information indicating whether or not the air conditioner is driven at the current time. It is determined whether or not a certain variable Fac is “OFF” (step S706).

  Here, when it is determined that the variable Fac_0 is “ON” and the variable Fac is “OFF” (step S706: Yes), a flag indicating that the impulse valve is driven under the control of the ECU 100. “ON” is substituted into the IPV drive flag which is information (step S707).

  Next, under the control of the ECU 100, “0” is substituted into an IPV drive counter that is counter information indicating the number of times the impulse valve is driven (step S708).

  On the other hand, if it is determined that the variable Fac_0 is not “ON” or the variable Fac is not “OFF” as a result of the determination in step S706 described above (step S706: No), the impulse valve is driven under the control of the ECU 100. “OFF” is substituted into the IPV drive flag, which is flag information that means to perform (step S709).

  Next, under the control of the ECU 100, “0” is substituted into an IPV drive counter which is counter information indicating the number of times the impulse valve is driven (step S710).

  In the fifth embodiment, the control processing that focuses on the opening and closing operations of the impulse valve, in other words, the fail-safe processing of the impulse valve, is substantially the same as in the first embodiment described above with reference to FIG. Therefore, the description is omitted.

  In the above-described fourth embodiment, the method for determining whether or not to perform the fail-safe processing of the impulse valve depending on whether or not the start motor for starting the engine is driven has been described. Moreover, in 5th Embodiment, the method of determining whether to perform the fail safe process of an impulse valve according to whether the vehicle-mounted air conditioner is driven was demonstrated. However, the present embodiment is not limited to this. Typically, whether or not to perform the fail-safe processing of the impulse valve may be determined depending on whether or not an on-vehicle electrical system or electrical device shown below is driven. That is, as an on-vehicle electric system or electric device, an electric power steering, an electric water pump, an electric oil pump, and an electric supercharged turbo device, a so-called motor assist turbo drive state and stop state Among them, various electric systems or devices that generate electrical noise when changing from one state to the other state can be given.

(Examination of actions and effects according to this embodiment)
Next, with reference to FIG. 11, the effect | action and effect which concern on this embodiment are examined. FIG. 11 is a graph (FIG. 11 (a)) showing the relationship between the lift amount and the crank angle when the impulse valve according to this embodiment is normally driven from the fully closed state to the fully open state. FIG. 11B is a graph (FIG. 11B) showing a relationship between a lift amount and a crank angle at which the impulse valve is driven from the fully closed state to the fully opened state when an opening / closing abnormality occurs in the impulse valve according to the embodiment.

  As described above, the impulse valve EDU is input with a drive pulse signal for opening or closing the impulse valve from the ECU 100 such as an engine ECU, for example, so that the impulse valve EDU is fully opened at a LOW level where the voltage value is 0 V, for example. Alternatively, for example, the driving of the impulse valve is controlled so that the valve is fully closed at the HI level where the voltage value is 5V. The transition time between the fully open state and the fully closed state of the impulse valve is about 3 ms to about 5 ms, and the timing for opening and closing the impulse valve is very fast. As for the opening and closing of the impulse valve, the driving of the motor for opening and closing the impulse valve is started every time an edge at which the HI level and the LOW level of the driving pulse signal are switched is detected. The detection of this edge can be detected by using, for example, the time when the voltage value exceeds 2.5V or the time when the voltage value falls below 2.5V.

  Since the detection time of the edge of the drive pulse signal is closely related to the output control of the internal combustion engine, it is calculated by the ECU 100 such as the engine ECU. This greatly affects the output control of the internal combustion engine, such as worsening of emissions. For this reason, it is output from the ECU 100 to the impulse valve EDU (ECU) not by serial communication but by communication due to voltage change. Such communication by voltage change is, for example, a communication method substantially similar to control of an injector and a spark plug.

  Thus, by calculating the detection time of the edge of the drive pulse signal in the ECU 100, it is not necessary to provide a circuit for calculating the timing of the engine speed in the impulse valve EDU, and in the manufacturing process of the impulse valve EDU, Since it is not necessary to add a dedicated crank angle sensor for the impulse valve EDU, the cost can be reduced. More specifically, an internal combustion engine having an impulse valve can be controlled by adding an impulse valve EDU dedicated to the impulse valve to the ECU 100 that controls a general-purpose internal combustion engine, thereby reducing the manufacturing cost. Can do.

  Since the edge of the drive pulse signal is detected and the impulse valve is opened or closed, as shown in FIG. 11A, at normal times, for example, after the crank angle a2, the drive pulse signal is at the LOW level. When it is necessary to control the drive to the fully open state, as shown in FIG. 11B, when a voltage exceeding the voltage threshold of 2.5 V described above is detected by the electric noise described above, for example, the crank After the angle a2, the impulse valve is closed. When the impulse valve opening / closing abnormality occurs in this way, the impulse valve may be maintained in the fully closed state until the LOW level is detected from the HI level that is the edge of the drive pulse signal for transitioning to the fully opened state. sell. In this case, the impulse valve is in a fully closed state, and since the intake air leakage flow rate is small, the new intake air is not drawn into the cylinder, the output torque is lowered, and engine stall occurs.

  On the other hand, according to the first, fourth, and fifth embodiments described above, the possibility of occurrence of an abnormal opening / closing of the impulse valve is specified in advance, which is intended for output control of the internal combustion engine. It is possible to effectively prevent the malfunction of the opened / closed intake control valve. In particular, according to the first, fourth, and fifth embodiments, it is possible to omit the detection process of the occurrence of the opening / closing abnormality, the communication process for notifying the ECU 100 of the occurrence of the detected opening / closing abnormality, and the fail-safe process described above. As a result, the detection processing of the occurrence of the opening / closing abnormality, which is a time longer than the transition time (typically 3 to 5 ms) of the impulse valve, and the communication for notifying the ECU 100 of the occurrence of the detected opening / closing abnormality. A decrease in output torque due to the occurrence of an opening / closing abnormality in several cycles corresponding to the time required for the processing and the above-described fail-safe processing can be almost or completely avoided.

  Alternatively, according to the above-described second and third embodiments, the frequency and degree of malfunction of the intake control valve intended for output control of the internal combustion engine malfunction even when an impulse valve malfunction occurs. Can be significantly reduced.

  As a result, due to a malfunction in opening and closing of the impulse valve, the intended intake air pulsation is not generated, the output torque of the internal combustion engine is significantly reduced, or the intake amount of air into the cylinder is significantly reduced. It is possible to appropriately and effectively prevent the engine stall.

  The present invention is not limited to the above-described embodiments, and may be implemented in various forms. For example, the present invention is not limited to a gasoline engine, and may be applied to various internal combustion engines that use diesel gasoline or other fuels.

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

1 is a schematic configuration diagram conceptually showing a configuration of an engine system 10. FIG. It is the flowchart which showed the flow of the control processing of ECU which performs overall control of the internal combustion engine which concerns on this embodiment paying attention to the flag which shows whether the valve opening and closing of an impulse valve are performed. 4 is a flowchart showing a flow of control processing of an ECU that performs overall control of the internal combustion engine according to the present embodiment, paying attention to opening and closing operations of an impulse valve. It is a timing chart showing the opening and closing timing of the impulse valve according to the present embodiment. It is the flowchart which showed the flow of the control processing of ECU which performs overall control of the internal combustion engine which concerns on 2nd Embodiment paying attention to the flag which shows whether the valve closing abnormality generate | occur | produced with the impulse valve. FIG. 6A and FIG. 6B are graphs showing the correlation between the predetermined threshold value of the intake pipe pressure for detecting the occurrence of valve closing abnormality according to the second embodiment and the engine speed. is there. It is the flowchart which showed the flow of the control processing of ECU which performs overall control of the internal combustion engine which concerns on 2nd Embodiment paying attention to the valve opening and closing operation | movement of an impulse valve. It is the flowchart which showed the flow of the control processing of ECU which performs overall control of the internal combustion engine which concerns on 3rd Embodiment paying attention to the flag which shows whether the valve closing abnormality generate | occur | produced with the impulse valve. It is the flowchart which showed the flow of the control processing of ECU which performs overall control of the internal combustion engine which concerns on 4th Embodiment paying attention to the flag which shows whether the valve opening and closing of an impulse valve are performed. It is the flowchart which showed the flow of the control processing of ECU which performs overall control of the internal combustion engine which concerns on 5th Embodiment paying attention to the flag which shows whether the valve opening and closing of an impulse valve are performed. The graph (FIG. 11 (a)) showing the relationship between the lift amount and the crank angle when the impulse valve according to the present embodiment is normally driven from the fully closed state to the fully opened state, and the impulse valve according to the present embodiment. FIG. 11B is a graph (FIG. 11B) showing the relationship between the lift amount that drives the impulse valve from the fully closed state to the fully open state and the crank angle when an open / close abnormality occurs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Engine system, 100 ... ECU, 101 ... Impulse valve EDU, 101 ... Injector EDU, 200 ... Engine, 202 ... Cylinder, 204 ... Intake pipe, 205 ... Surge tank, 206 ... Intake branch pipe, 206s ... Pressure sensor, 207 ... intake valve, 222 ... throttle valve, 224 ... impulse valve, CS ... crank angle sensor, TS ... temperature sensor.

Claims (8)

An intake passage for guiding intake air to the cylinder;
An intake control valve provided in the intake passage and capable of generating pulsation of the intake flow according to an open / close state;
An opening changing means for changing the opening of the intake control valve;
An output means for outputting an opening / closing instruction signal for instructing the intake control valve to open or close;
A specifying means for specifying occurrence of an opening / closing abnormality of the intake control valve or occurrence possibility of the opening / closing abnormality;
When the occurrence or possibility of occurrence is specified, in addition to controlling the output means to output the opening / closing instruction signal at a predetermined timing, the opening degree of the intake control valve is set to a predetermined opening degree. And a control means for controlling the opening degree changing means. An electric system for directly or indirectly assisting the operation of the internal combustion engine;
The specifying means may detect the occurrence of the opening / closing abnormality or the possibility of occurrence when the state changes from one state to another state in a start state in which the operation of the electric system starts and a stop state in which the operation of the electric system stops. 2. The control device for an internal combustion engine according to claim 1, wherein when the electric system maintains the one state or the other state, the generation or the possibility of occurrence is not specified. Detecting means for detecting pressure in the intake passage;
Measuring means for measuring the engine speed of the internal combustion engine,
The specifying means specifies the occurrence or possibility of the opening / closing abnormality based on a correlation between the detected pressure or a rate of change of the detected pressure and the measured engine speed. The control device for an internal combustion engine according to claim 1, wherein A flow rate detecting means for detecting the flow rate of the intake air;
The specifying means is configured to generate the opening / closing abnormality or based on a correlation between the detected pressure or a change rate of the detected pressure, the measured engine speed, and the detected flow rate. 4. The control device for an internal combustion engine according to claim 3, wherein occurrence possibility is specified.   5. The control unit according to claim 1, wherein the control unit controls the output unit to output the opening / closing instruction signal at a timing synchronized with a crank cycle as the predetermined timing. 6. The control apparatus of the internal combustion engine described in 1.   The said control means controls the said output means to output the said opening / closing instruction | indication signal at least once within the intake stroke of the said cylinder as the said predetermined timing, The any one of Claim 1 to 5 characterized by the above-mentioned. The control apparatus for an internal combustion engine according to claim 1. The intake passage is shared by a plurality of cylinders,
The control device for an internal combustion engine according to any one of claims 1 to 6, wherein one intake control valve is provided in the shared intake passage. As the intake passage, a plurality of intake passages for intake respectively included in a plurality of cylinders;
The intake control valve includes a plurality of intake control valves that are respectively provided in the plurality of intake passages and that can respectively generate the pulsation of the intake air according to an open / close state. The control apparatus for an internal combustion engine according to any one of the above.

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