JP5668458B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine having a variable compression ratio mechanism capable of changing an engine compression ratio and a variable valve mechanism capable of changing a valve timing of an engine valve.

  For example, Patent Document 1 discloses a first variable mechanism that can retard the center phase of the lift operating angle of an engine valve, and a second that can change an engine compression ratio by changing piston stroke characteristics. A variable mechanism, a third variable mechanism capable of enlarging and reducing the lift amount and valve operating angle of the engine valve, and if any of these variable mechanisms is determined to be abnormal A technology is disclosed in which the operation of a normal mechanism among the variable mechanisms is controlled to prevent interference between the engine valve and the piston.

Here, in order to variably control the engine compression ratio with the second variable mechanism, the reference compression ratio corresponding to the control position of the second variable mechanism, which becomes the reference when the engine compression ratio is changed by the second variable mechanism. For example, the second variable mechanism is driven as much as possible until it hits a mechanical stopper on the low compression ratio side where the engine compression ratio becomes low, and the second variable mechanism detected at this time is detected. 2 The control position of the variable mechanism is set to the reference compression ratio on the low compression ratio side. Further, the second variable mechanism is driven as much as possible until it hits a mechanical stopper on the high compression ratio side where the engine compression ratio becomes high, and the control position of the second variable mechanism detected at this time is set on the high compression ratio side. Use standard compression ratio. When changing the engine compression ratio, it is possible to cause the engine compression ratio to accurately follow the target engine compression ratio by controlling the drive of the second variable mechanism based on these reference compression ratios. It becomes.

Japanese Patent No. 4195351

  However, in the internal combustion engine as disclosed in Patent Document 1, for example, when at least one of the first or third variable mechanism other than the second variable mechanism is out of order, the second variable mechanism is used as the engine. When attempting to detect the reference compression ratio on the high compression ratio side by driving to the high compression ratio side where the compression ratio becomes high, the engine valve and the piston may interfere with each other.

  Therefore, according to the present invention, when the internal combustion engine is started, the variable compression ratio mechanism is driven in a direction in which the engine compression ratio becomes lower, and then the low compression ratio side reference compression ratio (control corresponding to the low compression ratio side reference compression ratio). Position or control amount), the valve timing of the engine valve is detected, and after the detection of the low compression ratio side reference compression ratio and the valve timing is detected, the variable compression ratio mechanism is moved in the direction of increasing the engine compression ratio. It is configured to detect a high compression ratio side reference compression ratio (control position or control amount corresponding to the high compression ratio side reference compression ratio) after driving.

  According to the present invention, the order of detection of the high compression ratio side reference compression ratio with respect to the detection of the low compression ratio side reference compression ratio and the detection of the valve timing is specified (the detection of the high compression ratio side reference compression ratio is performed later). The low compression ratio side reference compression ratio (control position or control amount corresponding to the low compression ratio side reference compression ratio) and the high compression ratio side reference compression ratio (high compression ratio) used for controlling the variable compression ratio mechanism when starting the internal combustion engine The interference between the engine valve and the piston can be avoided while the control position or control amount) corresponding to the side reference compression ratio is updated.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the outline of the system configuration | structure of the control apparatus of the internal combustion engine which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which showed typically the variable compression ratio mechanism applied to the control apparatus of the internal combustion engine which concerns on this invention. It is explanatory drawing which showed typically the link attitude | position of a variable compression ratio mechanism, (A) shows a high compression ratio position, (B) shows a low compression ratio position. The characteristic view which shows the piston motion of a variable compression ratio mechanism. Explanatory drawing which showed typically the positional relationship of a control link, a control shaft, etc. in the low compression ratio position and high compression ratio position in a variable compression ratio mechanism. The flowchart which shows the flow of the whole control at the time of start-up of the internal combustion engine which concerns on this invention. The subroutine which shows the content of the starting permission determination process in S1 of FIG. The subroutine which shows the content of the compression ratio initialization process in S2 of FIG. The subroutine which shows the content of the low compression ratio side reference | standard compression ratio initialization process in S24 of FIG. The subroutine which shows the content of the cranking process in S3 of FIG. The subroutine which shows the content of the start completion determination process in S4 of FIG. The timing chart which shows an example of the crank angle at the time of starting of the internal combustion engine in a comparative example, the valve timing of an intake valve, and a compression ratio. The timing chart which shows an example of the change of the crank angle at the time of the starting of the internal combustion engine in this embodiment, the valve timing of an intake valve, and a compression ratio.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  First, a basic configuration of an internal combustion engine to which the present invention is applied will be described. As shown in FIG. 1, the internal combustion engine 1 is roughly constituted by a cylinder head 1 a and a cylinder block 1 b, and an ignition for spark-igniting an air-fuel mixture in a combustion chamber 4 defined above a piston 3. A spark ignition internal combustion engine such as a gasoline engine provided with a plug 9. As is well known, the internal combustion engine 1 is driven by an intake cam 12a provided on an intake camshaft 12 to drive an intake valve 5 as an engine valve that opens and closes an intake port 7, and an exhaust camshaft 13 is provided with an exhaust valve. An exhaust valve 6 as an engine valve that is driven by a cam 13a to open and close the exhaust port 8, a fuel injection valve 10 that injects fuel into the intake port 7, and an upstream side of the intake collector 14 is opened and closed to adjust the intake air amount. And a variable valve mechanism 18 capable of continuously changing the valve timing of the intake valve 5 as a valve mechanism on the intake valve side that drives the intake valve 5 and the engine compression ratio can be changed. Variable compression ratio mechanism 20. In this embodiment, the valve mechanism on the exhaust valve side that drives the exhaust valve 6 is a valve mechanism that uses a general direct-acting cam (the phase of the lift / operating angle and lift center angle is fixed). (Not shown).

  The engine control module (ECM) 11 is a well-known digital computer having a CPU, a ROM, a RAM and an input / output interface. Throttle sensor signal to detect, water temperature sensor signal from water temperature sensor to detect engine water temperature, crank angle sensor signal from crank angle sensor to detect engine rotation speed, knock sensor signal from knock sensor to detect presence or absence of knocking, battery 17 is a rotational angle sensor signal and load sensor signal from the electric motor 21 that drives the control shaft 27 of the variable compression ratio mechanism 20 by the electric power supplied from 17, and an angular position sensor that detects the rotation angle of the control shaft 27 of the variable compression ratio mechanism 20. Based on various signals such as signals, the fuel injection valve 10, the ignition plug 9. Control signals are output to various actuators such as the throttle 15 and the electric motor 21 of the variable compression ratio mechanism 20 to control the fuel injection amount, fuel injection timing, ignition timing, throttle opening, engine compression ratio, etc. Control.

  The variable valve mechanism 18 is a so-called phase variable mechanism capable of delaying the phase of the lift center angle of the intake valve 5 in this embodiment, and is an intake camshaft driven by the crankshaft 22 of the internal combustion engine 1. 12, a sprocket (not shown) provided at the front end portion of the intake camshaft 12 and linked to the crankshaft 22 via a timing chain (not shown) or a timing belt (not shown), and the sprocket And a phase control actuator (not shown) for relatively rotating the intake camshaft 12 within a predetermined angle range. The phase control actuator is composed of, for example, a hydraulic rotary actuator, and is controlled via a hydraulic control valve (not shown) by a control signal from the ECM 11, and by the action of the phase control actuator, the sprocket and The intake camshaft 12 rotates relatively, and the phase of the lift center angle in the valve lift is retarded. The control state of the phase variable mechanism is detected by an intake camshaft sensor 19 that detects the rotational position of the intake camshaft 12 and is input to the ECM 11.

  As shown in FIGS. 2 and 3, the variable compression ratio mechanism 20 uses a multi-link type piston-crank mechanism in which the piston 3 and the crank pin 23 of the crankshaft 22 are linked by a plurality of links. A lower link 24 rotatably attached to the crankpin 23, an upper link 25 connecting the lower link 24 and the piston 3, a control shaft 27 provided with an eccentric shaft portion 28, an eccentric shaft portion 28 and a lower And a control link 26 connecting the link 24. One end of the upper link 25 is rotatably attached to the piston pin 30 and the other end is rotatably connected to the lower link 24 by a first connecting pin 31. One end of the control link 26 is rotatably connected to the lower link 24 by the second connecting pin 32, and the other end is rotatably attached to the eccentric shaft portion 28.

  The control shaft 27 is disposed in parallel with the crankshaft 22 and is rotatably supported by the cylinder block 1b. The control shaft 27 is rotationally driven by the electric motor 21 via the gear mechanism 29, and its rotational position is controlled.

  By changing the rotational position of the control shaft 27 by the electric motor 21, as shown in FIG. 3, the posture of the lower link 24 by the control link 26 changes, and the piston motion (stroke characteristic) of the piston 3, that is, the piston 3 The engine compression ratio is continuously changed and controlled with changes in the top dead center position and the bottom dead center position.

  In this embodiment, an angular position sensor 33 that detects the rotation angle of the control shaft 27 is provided, and the engine compression ratio set by the variable compression ratio mechanism 20 is detected by a detection signal from the angular position sensor 33. It is possible. As the angular position sensor 33, a sensor capable of detecting only a predetermined angle of the control shaft 27 can be used.

The variable compression ratio mechanism 20 includes an upper limit stopper (not shown) that defines an upper limit angle of the rotation angle of the control shaft 27 as a rotation angle limiter that defines upper and lower limit angles of the rotation angle of the control shaft 27; A lower limit stopper (not shown) for defining a lower limit angle of the rotation angle of the control shaft 27 and a stopper pin (not shown) provided so as to protrude in the radial direction of the control shaft 27 and be positioned between these upper and lower limit stoppers. Z). Engine compression ratio of the internal combustion engine 1, in the state where the stopper pin is pressed against the upper side stopper Pa, has a maximum compression ratio achievable by the variable compression ratio mechanism 20, the stopper pin is the lower limit stopper In the state of being abutted against the path, the minimum compression ratio that can be realized by the variable compression ratio mechanism 20 is obtained. In actual control, the variable compression ratio mechanism 20 has an engine compression ratio lower than the maximum compression ratio defined by the upper limit side stopper as a maximum value, and is lower than the minimum compression ratio defined by the lower limit side stopper. A high engine compression ratio is controlled as a minimum value.

  According to the variable compression ratio mechanism 20 using such a multi-link type piston-crank mechanism, in addition to improving the fuel consumption and output by optimizing the engine compression ratio according to the engine operating state, the piston and crank Compared with a single link mechanism in which a pin is connected by a single link, the piston stroke characteristic (see FIG. 4) itself can be optimized to a characteristic close to simple vibration, for example. Further, the piston stroke with respect to the crank throw can be made longer as compared with the single link mechanism, and the overall engine height can be shortened and the compression ratio can be increased. Furthermore, by optimizing the inclination of the upper link 25, the thrust load acting on the piston 3 and the cylinder can be reduced and optimized, and the weight of the piston 3 and the cylinder can be reduced. The actuator for driving the control shaft 27 is not limited to the illustrated electric motor 21 and may be a hydraulic drive device using a hydraulic control valve, for example.

  Further, as shown in FIG. 5, the variable compression ratio mechanism 20 may cause knocking or the like transiently when the change from the high compression ratio side to the low compression ratio side is delayed. The compression ratio changing speed is configured to be larger than the compression ratio changing speed on the low compression ratio side. Specifically, in the setting of the high compression ratio position, as compared with the setting of the low compression ratio position, the eccentricity connecting the link center line of the control link 26, the rotation center of the control shaft 27, and the center of the eccentric shaft portion 28. The angle formed by the line is close to a right angle, the arm length of the moment is increased, the drive moment by the electric motor 21 (actuator) is increased, and consequently the change speed is increased.

  When the variable compression ratio mechanism 20 variably controls the engine compression ratio of the internal combustion engine 1 in accordance with the operating state, the reference corresponding to the control position of the variable compression ratio mechanism 20 that serves as a reference when changing the engine compression ratio. It is important to accurately detect the compression ratio.

  Therefore, in this embodiment, when starting the internal combustion engine 1, the variable compression ratio mechanism 20 is driven to the low compression ratio side where the engine compression ratio is low and the high compression ratio side where the engine compression ratio is high, The low compression ratio side reference compression ratio (control position or control amount corresponding to the low compression ratio side reference compression ratio) and the high compression ratio side high compression ratio, which are the reference when changing the engine compression ratio The side reference compression ratio (control position or control amount corresponding to the high compression ratio side reference compression ratio) is updated so that the intake valve 5 and the piston 3 do not interfere with each other.

  FIG. 6 is a flowchart showing an overall control flow when the internal combustion engine 1 according to this embodiment is started. In S1, a start permission determination process is performed. In S2, a compression ratio initialization process for detecting a low compression ratio side reference compression ratio and a high compression ratio side reference compression ratio in the variable compression ratio mechanism 20 is performed. In S3, cranking is performed. Processing is performed, and in S4, start completion determination processing is performed.

  FIG. 7 is a subroutine showing the contents of the start permission determination process in S1 described above. In S11, the presence / absence of a request for starting the internal combustion engine 1 is read. For example, the presence / absence of an internal combustion engine start command from the outside such as an engine key operation by the driver is read. In S12, it is determined whether or not there is a start request. If there is a start request, the process proceeds to S13, the start permission flag is set to "ON", and if there is no start request, this subroutine is finished. . Note that the start permission flag is “OFF” at the time of an internal combustion engine stop command from the outside such as an engine key operation by the driver, for example.

FIG. 8 is a subroutine showing the contents of the compression ratio initialization process in S2 described above. In S21, the current start permission flag state is read. In S22, it is determined whether or not the current start permission flag is “ON”. If the start permission flag is “ON”, the process proceeds to S23, and if the start permission flag is “OFF”. If this is the case, this subroutine is terminated. In S23, it is determined whether or not the detection of the valve timing of the variable valve mechanism 18 is completed. If the detection of the valve timing of the variable valve mechanism 18 is not completed, the process proceeds to S24. To S25. In this embodiment, the variable valve mechanism 18 is a phase variable mechanism, and the detection of the valve timing of the variable valve mechanism 18 is completed when the rotational position of the intake camshaft 12 is detected by the intake camshaft sensor 19. It is determined. Further, in this embodiment, if the intake camshaft 12 is not rotating, the rotation position of the intake camshaft 12 cannot be detected by the intake camshaft sensor 19, so the routine proceeds to S25 after the cranking of the internal combustion engine 1 is started. It is like that. In S24, low compression ratio side reference compression ratio initialization processing for detecting the low compression ratio side reference compression ratio is performed. In S25, a predetermined engine compression ratio between the intake valve 5 and the piston 3 is defined as a boundary engine compression ratio at which the piston 3 interferes (begins to interfere with) the intake valve 5 from the rotational position of the intake camshaft 12 detected in S23. calculating a non-interfering compression ratio margin is secured, compared this with non-interfering compression ratio, engine compression ratio in the state where the stopper pin is abutted against the upper side stopper Pas and (maximum compression ratio) Then, the variable compression ratio mechanism 20 is driven so that the smaller compression ratio is obtained. That is, the a non-interfering compression ratio determined by the valve timing of the variable valve mechanism 18, the compression ratio towards the stopper pin is small compared to the engine compression ratio in a state of being abutted against the upper side stopper Pas Is detected as the high compression ratio side reference compression ratio. Incidentally, if the variable valve mechanism 18 is normal operable state, the engine compression ratio in the state where the stopper pin is abutted against the upper side stopper path has a higher compression ratio side reference compression ratio.

FIG. 9 is a subroutine showing the contents of the low compression ratio side reference compression ratio initialization process in S24 described above. In S241, the variable compression ratio mechanism 20 is driven to the low compression ratio side where the engine compression ratio becomes low. Specifically, the electric motor 21 is rotationally driven to the low compression ratio side where the engine compression ratio becomes low. Then, in a state where a command for driving the engine compression ratio to the low compression ratio side is output to the electric motor 21, the detected value of the angular position sensor 33 becomes a constant value for a predetermined time, and the rotation of the control shaft 27 Is determined to have stopped, the engine compression ratio at the control position of the variable compression ratio mechanism 20 at that time is detected as the low compression ratio side reference compression ratio (S242), and the process proceeds to S243. The detection of the low compression ratio side reference compression ratio is not completed until it is determined that the rotation of the control shaft 27 is stopped. In this case, the process does not proceed from S242 to S243, and this subroutine is finished. In S242, as the state where the rotation is determined to have stopped in the control shaft 27, for example, there is a state in which the stopper pin is abutted to the lower limit stopper Pas. In S243, with the completion of detection of the low compression ratio side reference compression ratio, the state of the cranking permission flag is set to “ON” and the cranking of the internal combustion engine 1 is permitted. In other words, until the detection of the low compression ratio side reference compression ratio is completed, the state of the cranking permission flag is “OFF”, and even if the start permission flag is “ON”, the internal combustion engine No cranking of 1 is performed.

  FIG. 10 is a subroutine showing the contents of the cranking process in S3 described above. In S31, the current states of the cranking permission flag and the start completion flag are read. In S32, it is determined whether or not the current cranking permission flag is “ON”. If the cranking permission flag is “ON”, the process proceeds to S34, and the start permission flag is “OFF”. If so, the process proceeds to S33. In S33, the starter motor is stopped. In S34, it is determined whether or not the current start completion flag state is “ON”. If the start completion flag state is “ON”, the process proceeds to S33, and if the start completion flag state is “OFF”. If so, the process proceeds to S35. In S35, the starter motor is driven to perform cranking.

  FIG. 11 is a subroutine showing the contents of the start completion determination process in S4 described above. In S41, the engine speed of the internal combustion engine 1 is detected. If the engine speed is equal to or higher than a predetermined speed (for example, idle speed), it is determined that the internal combustion engine 1 has been started, and the process proceeds to S42. Otherwise, it is determined that the internal combustion engine 1 has not yet been started, and this subroutine is finished. In S42, the state of the start completion flag is set to “ON”.

  FIG. 12 is a timing chart showing an example of changes in the crank angle, the valve timing of the intake valve, and the compression ratio when the internal combustion engine is started in the comparative example. FIG. 13 is a timing chart showing an example of changes in the crank angle at the start of the internal combustion engine, the valve timing of the intake valve 5 and the compression ratio in the present embodiment. The internal combustion engine of the comparative example shown in FIG. 12 is an internal combustion engine having the same configuration as that of the above-described embodiment, and the low compression ratio side reference compression ratio and the high compression ratio side of the variable compression ratio mechanism before the start of cranking. Except for detecting both of the standards, the conditions are the same as in the present embodiment shown in FIG.

As shown in FIG. 12, in the comparative example, both the low compression ratio side reference compression ratio and the high compression ratio side reference compression ratio of the variable compression ratio mechanism are detected before the cranking is started. Therefore, the valve timing of the variable valve mechanism is not detected when the high compression ratio side reference compression ratio of the variable compression ratio mechanism is detected. That is, when the internal combustion engine is stopped last (immediately before), for example, part of the movable portion of the phase change mechanism as variable valve mechanism is fixed, when the valve timing of the intake valve is fixed to the phrase valve timing, When the variable compression ratio mechanism is driven to the high compression ratio side where the engine compression ratio becomes high to detect the high compression ratio side reference compression ratio, the piston may interfere with the intake valve. In FIG. 12, t1 is the timing when the internal combustion engine is requested to start, t2 is the timing when cranking starts, and t3 is the timing when the valve timing of the variable valve mechanism is detected. Further, since the valve timing of the variable valve mechanism is not detected until the timing of t3, the engine compression ratio is limited from the timing of t3 according to the valve timing of the variable valve mechanism as shown by the broken line in FIG. Is receiving.

On the other hand, in this embodiment, as shown in FIG. 13, cranking of the internal combustion engine 1 is started, and the variable compression ratio mechanism 20 is changed from the timing T3 when the valve timing of the variable valve mechanism 18 is detected. Drives to the higher compression ratio side. That is, when the variable compression ratio mechanism 20 is driven to the high compression ratio side, the piston top dead center position where the intake valve 5 and the piston 3 interfere from the valve timing of the variable valve mechanism 18 (interference piston top dead center position). ) Is calculated, and the limit value of the engine compression ratio according to the valve timing of the variable valve mechanism 18 is calculated from the top dead center position of the interference piston as indicated by a broken line in FIG. Then, by using the detection value of the angular position sensor 33 for detecting the rotation angle of the control shaft 27, if in the case where the variable valve mechanism 18 is valve timing of the failed intake valve is fixed to the phrase valve timing Even so, the variable compression ratio mechanism 20 can be controlled to the maximum high compression ratio side so as to avoid interference between the intake valve 5 and the piston 3, and the high compression ratio side reference compression ratio can be detected accurately. can do. When the detection of the high compression ratio side reference compression ratio is completed at the timing of T4, the variable compression ratio mechanism 20 is controlled to be the target engine compression ratio (target ε) at the start.

  Further, when the internal combustion engine 1 is started, the low compression ratio side reference compression ratio and the high compression ratio side reference compression ratio can be detected, so that the detected low compression ratio side reference compression ratio and high compression ratio side reference compression ratio can be detected. Accordingly, the resolution of the variable compression ratio mechanism 20 can be changed, and the rotation angle of the control shaft 27 with respect to the control amount (target engine compression ratio) can be updated.

  When there is a request to start the internal combustion engine 1 (timing T1), the variable compression ratio mechanism 20 is driven to the low compression ratio side, and when detection of the low compression ratio side reference compression ratio is completed (timing T2), the engine Cranking of the internal combustion engine 1 is started with the compression ratio maintained at the low compression ratio side reference compression ratio. In other words, in the present embodiment, since the variable compression ratio mechanism 20 is driven only to the low compression ratio side and only the low compression ratio side reference compression ratio is detected before cranking starts, cranking of the internal combustion engine starts. Compared to the above-described comparative example in which the variable compression ratio mechanism is driven on the low compression side and on the high compression ratio side, the time from the start request of the internal combustion engine 1 to the start of cranking of the internal combustion engine 1 is shortened. be able to. When the internal combustion engine 1 is started, the engine speed increases more smoothly when the engine compression ratio is lower. Therefore, as in this embodiment, the engine compression ratio is set to the low compression ratio side reference compression ratio. Starting the cranking of the internal combustion engine 1 in a state maintained in this manner is also advantageous from the viewpoint of startability.

  Further, in this embodiment, the upper limit of the engine compression ratio that can be changed by the variable compression ratio mechanism 20 until the timing of T3 when the valve timing of the intake valve is detected is the start of the characteristic line A indicated by the one-dot chain line in FIG. It is controlled to be equal to or less than the upper limit compression ratio. This upper limit compression ratio at the time of starting is set to an engine compression ratio at which the intake valve 5 and the piston 3 do not interfere with each other regardless of whether the variable valve mechanism 18 has failed or not. Even at the timing before the detected T3, it is possible to reliably avoid the interference between the intake valve 5 and the piston 3.

  Before the timing T3 at which the valve timing is detected, the engine compression ratio may be controlled toward the highest compression ratio as long as it is in the range equal to or lower than the upper limit compression ratio at the start of the characteristic line A. The reference compression ratio may be detected after detection of the low compression ratio side reference compression ratio and detection of the valve timing. That is, it is needless to say that the timing at which the variable compression ratio mechanism starts to be driven in the direction in which the engine compression ratio increases does not necessarily have to be after detection of the low compression ratio side reference compression ratio and detection of the valve timing. .

Also, keep the above-described embodiment, the engine compression ratio set by the variable compression ratio mechanism 20, the detection signal whether et Starring angular position sensor 33 for detecting the rotation angle of the control shaft 27 of the variable compression ratio mechanism 20 Although calculated, the engine compression ratio set by the variable compression ratio mechanism 20 can also be calculated from the rotation angle sensor signal from the electric motor 21 that drives the control shaft 27 of the variable compression ratio mechanism 20, and the angular position Even if the sensor 33 is omitted, it is possible to avoid interference between the intake valve 5 and the piston 3 when detecting the high compression ratio side reference compression ratio.

  In the above-described embodiment, the variable valve mechanism 18 is a phase variable mechanism that can retard the phase of the lift center angle of the intake valve 5, but the variable valve mechanism 18 is as described above. It is not limited to a variable phase mechanism, but is a lift operating angle variable mechanism that changes the valve lift amount and operating angle of the intake valve 5, or a combination of the phase variable mechanism and the lift operating angle variable mechanism. May be. Of course, the detection of the valve timing when the lift operating angle variable mechanism is employed may be based on the maximum lift amount.

  Further, the present invention can be applied not only to the valve mechanism on the intake valve side but also to the variable valve mechanism in which the valve mechanism on the exhaust valve side can continuously change the valve timing of the exhaust valve. . In that case, the high compression ratio side reference compression ratio is detected after detecting the valve timing of the variable valve mechanism on the intake valve side and the valve timing of the variable valve mechanism on the exhaust side.

DESCRIPTION OF SYMBOLS 3 ... Piston 5 ... Intake valve 11 ... Engine control module 18 ... Variable valve mechanism 20 ... Variable compression ratio mechanism 27 ... Control shaft 33 ... Angular position sensor

Claims (5)

A variable compression ratio mechanism that can continuously change the engine compression ratio by changing the top dead center position of the piston, and a variable valve mechanism that can change the valve timing of the engine valve,
When starting the internal combustion engine, the variable compression ratio mechanism is a compression ratio at which the maximum drive control can be performed on the low compression ratio side, and the low compression ratio side becomes a reference when changing the engine compression ratio. The compression ratio side reference compression ratio and the compression ratio mechanism at which the variable compression ratio mechanism can perform maximum drive control to the high compression ratio side, and the high compression ratio side that is the reference when changing the engine compression ratio the controller of an internal combustion engine to update the compression ratio side reference compression ratio, and
The variable compression ratio mechanism of the engine compression ratio is driven in the direction the detecting a low compression ratio side reference compression ratio from low to detect the valve timing of the engine valve, the detection of the low compression ratio side reference compression ratio and characterized in that the after having undergone the detection of the valve timing, and is configured so as to detect the pre-Symbol high compression ratio side reference compression ratio by driving the variable compression ratio mechanism engine compression ratio becomes higher the direction A control device for an internal combustion engine. When there is an abnormality in the valve timing of the engine valve, the engine compression ratio at which the engine valve and the piston interfere with each other is calculated from the valve timing of the engine valve, and the variable compression ratio mechanism is used to increase the engine compression ratio. In addition, the maximum drive so that the engine valve and the piston do not interfere,
The high compression ratio side reference compression ratio is detected by maximally driving the variable compression ratio mechanism in a direction in which the engine compression ratio increases when there is no abnormality in the valve timing of the engine valve. The control apparatus for an internal combustion engine according to claim 1.   3. The engine compression ratio that can be changed by the variable compression ratio mechanism is controlled to be equal to or less than a predetermined starting upper limit compression ratio until the valve timing of the engine valve is detected. The control apparatus of the internal combustion engine described in 1. In response to a start command for the internal combustion engine, after the variable compression ratio mechanism is driven in a direction in which the engine compression ratio is reduced and the low compression ratio side reference compression ratio is detected, cranking of the internal combustion engine is started,
Detecting the valve timing of the engine valve after cranking of the internal combustion engine,
4. The high compression ratio side reference compression ratio is detected by driving the variable compression ratio mechanism in a direction in which the engine compression ratio becomes higher after detecting the valve timing of the engine valve. The control apparatus of the internal combustion engine in any one. The variable compression ratio mechanism includes a plurality of link members you consolidated the piston and the crankshaft of the internal combustion engine, a control link for limiting the freedom of the link member, rotatably in a cylinder block of the internal combustion engine A control shaft having an eccentric shaft portion that is supported and eccentric from the rotation center thereof, and a base end of the control link is swingably connected to the eccentric shaft portion of the control shaft, The engine compression ratio changes depending on the position of the eccentric shaft portion according to the rotational position,
An angular position sensor for detecting a rotation angle of the control shaft;
The control amount of the engine compression ratio when the variable compression ratio mechanism is driven in the direction of increasing the engine compression ratio after detecting the valve timing of the engine valve, the detected valve timing of the engine valve and the angular position The control device for an internal combustion engine according to any one of claims 1 to 4, wherein the control device is set based on a detection value of the sensor.

Images