JP2013194552A - Control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To early and securely perform independent displacement to an intermediate lock phase at the time of engine starting.SOLUTION: An internal combustion engine includes a variable valve timing mechanism having an intermediate lock mechanism. When the intermediate lock mechanism is operating at the time of engine starting (S101:NO), a waste gate valve is opened (S103) to improve the warm-up performance of a catalyst. In contrast, when the intermediate lock mechanism is not operating at the time of engine starting (S101:YES), the waste gate valve is closed (S102) and a back pressure of the internal combustion engine is raised to control a rise of engine rotational speed, thereby increasing the amplitude of a relative oscillation due to a cam torque change of two rotors in the variable valve timing mechanism and raising the operability of the intermediate lock mechanism.

Description

  The present invention relates to an internal combustion engine control apparatus that controls an internal combustion engine that includes a variable valve timing mechanism with an intermediate lock mechanism.

  As a mechanism applied to an internal combustion engine such as a vehicle, a valve timing variable mechanism that varies the valve timing of an engine valve is known. The variable valve timing mechanism includes a first rotating body that is drivingly connected to the camshaft and a second rotating body that is drivingly connected to the crankshaft, and the camshaft rotates by relative rotation of these rotating bodies. A mechanism for changing the valve timing of the engine valve by changing the phase has been put into practical use.

  In the mechanism that performs the relative rotation of the two rotating bodies by hydraulic pressure, the supply of hydraulic pressure is insufficient when the engine is started, and the valve timing cannot be maintained only by the hydraulic pressure. For this reason, such a variable valve timing mechanism is provided with a lock mechanism that mechanically locks the relative rotation of both rotating bodies, and the internal combustion engine is stopped while the lock mechanism is operated, so that the The valve timing is maintained at a timing suitable for starting.

  On the other hand, in recent years, an intermediate lock mechanism that locks the relative rotation in the middle of the relative rotation range of the rotating body is provided in order to enable control to the retard side with respect to the valve timing at the time of engine start. The provided valve timing variable mechanism is also in practical use. In such a variable valve timing mechanism with an intermediate lock mechanism, if the operation of the intermediate lock mechanism fails when the engine is stopped, the valve timing at the start of the engine cannot be maintained at a timing suitable for starting, and sufficient startability is ensured. It becomes impossible.

  On the other hand, during rotation, the rotating camshaft was assisted by the torque in the counter-rotating direction (negative cam torque) accompanying the pressing down of the engine valve against the biasing force of the valve spring and the biasing force of the valve spring. The torque (positive cam torque) in the rotational direction accompanying the push-up of the engine valve acts alternately. In a state where the hydraulic pressure is released and the relative rotation between the first rotating body and the second rotating body is not restricted, the fluctuation of the cam torque causes the first rotating body to swing with respect to the second rotating body. To do. Thus, in this type of variable valve timing mechanism, the relative rotation phase of the two rotating bodies is changed to the intermediate lock phase where the relative rotation is locked by the intermediate lock mechanism by such swinging according to the fluctuation of the cam torque. It is designed to move independently. Incidentally, Patent Document 1 discloses a variable valve timing mechanism with an intermediate lock mechanism that includes a ratchet mechanism that makes it easier and more reliable for the self-sustaining displacement of the variable valve timing mechanism using such cam torque fluctuations.

Japanese Patent Laid-Open No. 2002-122009

  By the way, in order to perform such a self-sustained displacement to the intermediate lock phase at an early stage and with certainty, the swing amplitude of the first rotating body due to the cam torque fluctuation must be sufficiently large. However, depending on the situation, after the cranking is started, the engine rotational speed increases early, and the self-sustained displacement of the first rotating body to the intermediate lock phase and thus the operation of the intermediate lock mechanism can be performed early and accurately. There may not be.

  The present invention has been made in view of such circumstances, and a problem to be solved is to enable early and reliable self-sustained displacement to an intermediate lock phase at the time of engine start.

  In order to solve the above-mentioned problem, the invention described in claim 1 is provided with a first rotating body drivingly connected to the camshaft, and coaxially arranged with the first rotating body so as to be relatively rotatable. And a second rotary body that is drivingly connected to the crankshaft, and an intermediate lock mechanism that mechanically locks the relative rotation of the rotary bodies in the middle of the relative rotation range of the rotary bodies. And a turbocharger with a wastegate valve that adjusts a flow rate of exhaust gas that bypasses the exhaust turbine, wherein the rotation by the intermediate lock mechanism is performed at the start of engine start. When the relative rotation of the body is not locked, the wastegate valve opening is smaller than when the lock is locked at the start of the engine start. And comb.

  In the above configuration, when the relative rotation of the two rotating bodies is not locked by the intermediate lock mechanism at the start of the engine start, the opening degree of the waste gate valve is reduced, so that the flow rate of the exhaust gas bypassing the exhaust turbine is reduced. Reduced. When the flow rate of the exhaust gas that bypasses the exhaust turbine is reduced in this way, the flow resistance of the exhaust gas in the exhaust passage increases, the back pressure of the internal combustion engine increases, and the engine speed decreases. As a result, the cam torque fluctuation period becomes longer, and the swing amplitude of the first rotating body with respect to the second rotating body increases. Therefore, according to the above configuration, when the relative rotation is not locked by the intermediate lock mechanism at the start of engine start, the self-sustained displacement of the first rotating body to the intermediate lock phase where the lock is performed is performed. This can be done earlier and more reliably.

  On the other hand, when the engine start is started with the intermediate lock mechanism activated, the opening degree of the waste gate valve is increased. Therefore, at this time, the temperature of the exhaust gas flowing into the catalyst rises, and the warm-up property of the catalyst is improved.

  Further, when the engine is started, when the rotation of the rotating body is not locked by the intermediate lock mechanism, the waste gate valve is closed as in claim 2 to start the engine. When it is locked at the start, it becomes more prominent by opening the waste gate valve.

  In order to solve the above-mentioned problem, the invention according to claim 3 is provided with a first rotating body drivingly connected to the camshaft, and coaxially arranged with the first rotating body so as to be relatively rotatable. And a second rotating body driven and connected to the crankshaft, and an intermediate lock mechanism that mechanically locks the relative rotation of the rotating bodies in the middle of the relative rotation range of the rotating bodies. In an internal combustion engine control device that controls an internal combustion engine that includes a variable mechanism and a turbocharger with a variable nozzle that adjusts the flow rate of exhaust gas blown to an exhaust turbine, the first and the first locks by the intermediate lock mechanism at the start of engine start When the relative rotation of the second rotating body is not locked, the exhaust turbine is blown to the exhaust turbine as compared to when the locking is performed at the start of the engine start. Air flow rate is controlled opening of the variable nozzle to be higher.

  In the above configuration, the variable nozzle of the turbocharger is configured so that the exhaust spray speed to the exhaust turbine is higher when the relative rotation of the rotating body is not locked by the intermediate lock mechanism at the start of engine start. Is controlled. As a result, the flow resistance of the exhaust gas in the exhaust passage increases, the back pressure of the internal combustion engine increases, and the engine speed decreases. For this reason, the fluctuation period of the cam torque becomes longer, and the swing amplitude of the first rotating body with respect to the second rotating body becomes larger. Therefore, according to the above configuration, when the relative rotation is not locked by the intermediate lock mechanism at the start of engine start, the self-sustained displacement of the first rotating body to the intermediate lock phase where the lock is performed is performed. This can be done earlier and more reliably.

  Furthermore, in order to solve the above-mentioned problem, the invention according to claim 4 is arranged such that a first rotating body drivingly connected to the camshaft and a coaxial with the first rotating body so as to be relatively rotatable. And a second rotating body that is driven and connected to the crankshaft, and an intermediate lock mechanism that mechanically locks the relative rotation of the rotating bodies in the middle of the relative rotation range of the rotating bodies. In an internal combustion engine control apparatus that controls an internal combustion engine having a variable timing mechanism, when the relative rotation of the rotating body is not locked by the intermediate lock mechanism at the start of engine start, The flow resistance of the exhaust gas in the exhaust passage of the internal combustion engine is increased compared to when the locking is performed.

  In the above configuration, when the relative rotation of the rotating body is not locked by the intermediate lock mechanism at the start of engine start, the flow resistance of the exhaust gas in the exhaust passage increases, and the back pressure of the internal combustion engine increases, The engine speed decreases. For this reason, the fluctuation period of the cam torque becomes longer, and the swing amplitude of the first rotating body with respect to the second rotating body becomes larger. Therefore, according to the above configuration, when the relative rotation is not locked by the intermediate lock mechanism at the start of engine start, the self-sustained displacement of the first rotating body to the intermediate lock phase where the lock is performed is performed. This can be done earlier and more reliably.

  According to claim 5, the ratchet mechanism for guiding the relative rotation phase of the first and second rotating bodies to the phase where the relative rotation is locked by the intermediate lock mechanism is provided to the variable valve timing mechanism. If the relative rotation is not locked by the intermediate lock mechanism at the start of engine start, the self-sustained displacement of the first rotating body to the intermediate lock phase where the lock is performed is further increased. It can be done early and reliably.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic which shows typically the whole structure of the control apparatus of the internal combustion engine concerning the 1st Embodiment of this invention. Sectional drawing which shows the plane sectional structure of the valve timing variable mechanism provided in the internal combustion engine to which the embodiment is applied. Sectional drawing which shows the side part sectional structure of the valve timing variable mechanism along the AA line of FIG. (A)-(d) The figure which shows the aspect of the self-displacement operation | movement of the vane rotor in a valve timing variable mechanism. (A)-(d) The figure which shows the aspect of the self-displacement operation | movement of the vane rotor in the valve timing variable mechanism seen from the viewpoint different from FIG. The flowchart which shows the process sequence of the waste gate valve control routine at the time of a start applied to the embodiment. (A)-(c) The time chart which shows an example of the control aspect at the time of engine starting of the embodiment. (A)-(d) The graph which shows transition of the cam torque and vane rotor displacement in each at the time of high rotation and low rotation. (A), (b) The schematic which shows operation | movement of the variable nozzle provided in the turbocharger of the internal combustion engine to which the 2nd Embodiment of this invention is applied.

(First embodiment)
Hereinafter, a second embodiment of the internal combustion engine control device according to the present invention will be described in detail with reference to FIGS.

  First, the configuration of the control device for an internal combustion engine according to the present embodiment will be described with reference to FIG. An air cleaner 2 for purifying the air taken into the intake passage 1 is provided at the most upstream portion of the intake passage 1 of the internal combustion engine. A compressor 4 of a turbocharger 3 that compresses intake air is disposed downstream of the air cleaner 2 in the intake passage 1, and an intercooler 5 that cools intake air that has become hot due to adiabatic compression in the compressor 4. Is arranged. A throttle valve 6 for adjusting the amount of intake air is disposed downstream of the intercooler 5 in the intake passage 1. The intake passage 1 is connected to the combustion chamber 9 via an intake valve 8. The internal combustion engine is provided with a variable valve timing mechanism 10 that makes the valve timing of the intake valve 8 variable.

  The combustion chamber 9 is connected to the exhaust passage 13 via the exhaust valve 11. An exhaust turbine 14 of the turbocharger 3 that drives the compressor 4 by the flow of exhaust is disposed in the exhaust passage 13. The turbocharger 3 is provided with a waste gate valve 15 that adjusts the flow rate of exhaust gas that bypasses the exhaust turbine 14. A catalytic converter 16 that purifies the exhaust gas is disposed downstream of the exhaust turbine 14 in the exhaust passage 13.

  Such an internal combustion engine is controlled by an electronic control unit 17. The electronic control unit 17 includes a central processing unit (CPU) that performs various arithmetic processes for engine control, a read-only memory (ROM) that stores programs and data for engine control, CPU arithmetic results and sensor A random access memory (RAM) for temporarily storing detection results and the like is provided. The electronic control unit 17 includes an ignition switch 18 that is a switch for starting and stopping the internal combustion engine, a crank angle sensor 19 that detects the rotational phase of the crankshaft, a cam angle sensor 20 that detects the rotational phase of the camshaft, and the like. Sensor detection signals are input. The electronic control unit 17 performs engine control based on signals from these sensors.

Next, details of the variable valve timing mechanism 10 installed in such an internal combustion engine will be described with reference to FIGS.
As shown in FIG. 2, the variable valve timing mechanism 10 is provided with a vane rotor 100. The vane rotor 100 is fixed to the end portion of the intake camshaft of the internal combustion engine so as to be integrally rotatable. A plurality of vanes 102 are formed on the outer periphery of the vane rotor 100 so as to protrude in the radial direction. Such a vane rotor 100 is accommodated in the housing 101.

  The housing 101 is coaxial with the vane rotor 100 and is disposed so as to be relatively rotatable. The housing 101 is drivingly connected to the crankshaft of the internal combustion engine via a winding transmission mechanism such as a timing belt mechanism or a chain mechanism. On the inner periphery of the housing 101, the same number of recesses 103 as the vanes 102 for accommodating the vanes 102 of the vane rotor 100 are formed. Each recess 103 is partitioned into two oil chambers by vanes 102. Of these, the oil chamber formed in the direction opposite to the camshaft rotation direction of the vane 102 (clockwise direction in the drawing, hereinafter referred to as the advance angle direction) advances the vane rotor 100 with respect to the housing 101. An advance oil chamber 104 into which hydraulic pressure for relative rotation in the direction is introduced. On the other hand, the oil chamber formed in the camshaft rotation direction of the vane 102 (counterclockwise direction in the drawing; hereinafter referred to as a retarded angle direction) makes the vane rotor 100 relative to the housing 101 in the retarded direction. A retard oil chamber 105 into which hydraulic pressure for rotation is introduced. In the variable valve timing mechanism 10, the vane rotor 100 has a configuration corresponding to “a first rotating body drivingly connected to the camshaft”. Further, the housing 101 has a configuration corresponding to “a second rotating body that is coaxial with the first rotating body and is rotatably arranged and is drivingly connected to the crankshaft”.

  One of the vanes 102 of the vane rotor 100 is provided with a lock pin 106. As shown in FIG. 3, the lock pin 106 is urged downward in the figure by a spring 107. On the other hand, the housing 101 is formed with a lock hole 108 that can be engaged with the lock pin 106. The lock hole 108 is formed at a position that is in phase with the lock pin 106 when the vane rotor 100 is positioned in the middle of the rotation range with respect to the housing 101. The lock pin 106 is applied with a hydraulic pressure in a direction (upward in the drawing) away from the lock hole 108 according to the supply of the hydraulic pressure to the advance oil chamber 104 or the retard oil chamber 105. It has become. The rotation position of the vane rotor 100 when the lock pin 106 engages with the lock hole 108 is set to a position where the valve timing of the intake valve is the optimum valve timing for engine start.

  On the other hand, a stepped ratchet groove 109 is formed in the housing 101 continuously to the lock hole 108. The ratchet groove 109 extends from the lock hole 108 in the counter-rotating direction of the camshaft, and is formed such that the groove depth gradually decreases as the distance from the lock hole 108 increases. In the following, the portion having the shallowest groove depth of the ratchet groove 109 will be referred to as the first stage of the ratchet groove 109, and the second and third stages of the ratchet groove 109 will be described in order of increasing groove depth. It is described as “eyes”.

Next, the operation of the variable valve timing mechanism 10 configured as described above will be described.
In the variable valve timing mechanism 10 at the start of engine start, each advance oil chamber 104 and each retard oil chamber 105 are not filled with oil. Normally, the engine is started with the lock pin 106 engaged with the lock hole 108 and the intermediate lock mechanism is activated.

  When the engine start is completed and sufficient hydraulic pressure can be secured, each advance oil chamber 104 and each retard oil chamber 105 are filled with oil. At the same time, hydraulic pressure is applied to the lock pin 106, and the lock pin 106 is released from the lock hole 108 against the urging force of the spring 107. Thereby, the operation of the intermediate lock mechanism is released, and the relative rotation of the vane rotor 100 and the housing 101 is allowed.

  When the operation of the intermediate lock mechanism is released, variable valve timing control by adjusting the hydraulic pressure of the advance oil chamber 104 and the retard oil chamber 105 is started. For example, when the hydraulic pressure in the advance oil chamber 104 is increased and the hydraulic pressure in the retard oil chamber 105 is decreased, the vane rotor 100 rotates in the advance direction with respect to the housing 101 due to the hydraulic pressure difference between both sides of the vane 102. To do. As a result, the rotational phase of the intake camshaft coupled to the vane rotor 100 so as to be integrally rotatable is advanced, and the valve timing of the intake valve 8 that is opened and closed by the rotation of the intake camshaft is advanced. Further, when oil is supplied to the retarded oil chamber 105 to increase its internal hydraulic pressure and oil is extracted from the advanced oil chamber 104 to lower its internal hydraulic pressure, the vane rotor is caused by the hydraulic pressure difference between both sides of the vane 102. 100 rotates in a retarding direction with respect to the housing 101. As a result, the rotational phase of the intake camshaft connected to the vane rotor 100 so as to be integrally rotatable is retarded, and the valve timing of the intake valve 8 that is opened and closed by the rotation of the intake camshaft is delayed. Further, when the hydraulic pressures of the advance oil chamber 104 and the retard oil chamber 105 are balanced, the hydraulic pressures acting on both sides of the vane 102 are balanced, and the rotation of the vane rotor 100 with respect to the housing 101 is stopped. As a result, the rotational phase of the intake camshaft and the valve timing of the intake valve 8 are maintained. In this way, the variable valve timing mechanism 10 during engine operation is operated so as to obtain the valve timing of the intake bubble suitable for the engine operating condition.

  When the engine is stopped, the hydraulic pressure is released from the advance oil chamber 104 and the retard oil chamber 105. At this time, in the variable valve timing mechanism 10, the vane rotor 100 is displaced autonomously until the phase (intermediate lock phase) in which the relative rotation is locked by the intermediate lock mechanism. That is, in the variable valve timing mechanism 10, the ratchet mechanism that guides the phase of relative rotation of the vane rotor 100 and the housing 101 to the intermediate lock phase is configured by the lock pin 106, the spring 107, and the ratchet groove 109. The vane rotor 100 is rotated to the intermediate lock phase by the action of the ratchet mechanism.

  For example, as shown in FIGS. 4A and 5A, when the engine stop is started, the vane rotor 100 moves to the end of the relative rotation range with respect to the housing 101 in the retard direction (the most retarded phase). Is located. When the hydraulic pressure in the advance oil chamber 104 and the retard oil chamber 105 is released in this state, the vane rotor 100 can freely rotate with respect to the housing 101.

  On the other hand, torque (cam torque) accompanying opening and closing of the intake valve acts on the rotating intake camshaft. That is, when the intake valve is opened against the urging force of the valve spring, the camshaft counter-rotating direction torque, that is, the negative cam torque acts on the intake camshaft, and the intake air is assisted by the urging force of the valve spring. Depending on the valve closing, torque in the camshaft rotation direction, that is, positive cam torque acts on the intake camshaft. Therefore, positive and negative cam torques alternately act on the rotating intake camshaft.

  The vane rotor 100 that can freely swing due to the hydraulic pressure being released from the advance oil chamber 104 and the retard oil chamber 105 swings relative to the housing 101 due to such fluctuations in the cam torque. When the vane rotor 100 is rotated by a certain amount in the advance direction due to this swinging, the lock pin 106 is engaged with the first stage of the ratchet groove 109 as shown in FIGS. 4B and 5B. become. As a result, the rotation of the vane rotor 100 in a direction retarded from the engagement phase of the lock pin 106 with respect to the first stage of the ratchet groove 109 is restricted, and the swing range of the vane rotor 100 is displaced in the advance direction. Become.

  In this state, when the vane rotor 100 is further rotated by a certain amount in the advance angle direction, the lock pin 106 is engaged with the second stage of the ratchet groove 109 as shown in FIGS. 4 (c) and 5 (c). It becomes like this. As a result, the rotation of the vane rotor 100 in a direction retarded from the engagement phase of the lock pin 106 with respect to the second stage of the ratchet groove 109 is restricted, and the swing range of the vane rotor 100 is further displaced in the advance direction. It becomes like this.

  Thus, the vane rotor 100 gradually rotates in the advance direction with respect to the housing 101. Finally, as shown in FIGS. 4D and 5D, the vane rotor 100 is rotated to the intermediate lock phase, and the lock pin 106 is engaged with the lock hole 108. As a result, the valve timing of the intake valve is maintained at the optimum valve timing for engine starting even when the engine cannot be secured with sufficient hydraulic pressure.

  By the way, in the internal combustion engine provided with such a variable valve timing mechanism 10, the waste gate valve 15 is opened when the engine is started. When the waste gate valve 15 is opened, the exhaust gas bypasses the exhaust turbine 14 and flows directly into the catalytic converter 16. Thereby, the temperature of the exhaust gas flowing into the catalytic converter 16 increases, and the temperature rise of the exhaust gas provided in the catalytic converter 16 is promoted.

  On the other hand, as described above, in this internal combustion engine, the intermediate lock mechanism of the variable valve timing mechanism 10 is operated when the engine is stopped. However, depending on the situation, the intermediate lock mechanism may not be operated when the engine is stopped. For example, when the internal combustion engine is suddenly stopped, the time until the internal combustion engine completely stops rotating may be too short, and the vane rotor 100 may not be able to fully rotate to the intermediate lock phase.

  In such a case, in order to ensure startability of the internal combustion engine, it is necessary to quickly rotate the vane rotor 100 to the intermediate lock phase after the start of the engine to operate the intermediate lock mechanism. The rotation of the vane rotor 100 to the intermediate lock phase at this time can be performed by utilizing the swing of the vane rotor 100 due to cam torque fluctuations and the action of the ratchet mechanism. Such rotation of the vane rotor 100 can be performed earlier and more reliably as the amplitude of the swing of the vane rotor 100 due to cam torque variation is larger.

  Therefore, in the present embodiment, the waste gate valve 15 is controlled in the following manner so that the vane rotor 100 can be rotated earlier and more reliably. That is, in this embodiment, the waste gate valve 15 at the time of engine start is controlled through the processing of the start-time waste gate valve (WGV) control routine shown in FIG. The processing of this routine is repeatedly executed periodically by the electronic control unit 17 after the start of the engine start.

  When the processing of this routine is started, it is first determined in step S100 whether or not the engine is starting. If the engine is not started (S100: NO), the process of this routine is terminated as it is. If the engine is started (S100: YES), the process proceeds to step S101.

  When the process proceeds to step S101, it is determined in step S101 whether or not the intermediate lock mechanism is operating. If the intermediate lock mechanism is not operating (S101: YES), the process proceeds to step S102. In step S102, after the waste gate valve 15 is opened, the current routine is terminated. On the other hand, if the intermediate lock mechanism is operating (S101: NO), the process proceeds to step S103. In step S103, after the waste gate valve 15 is closed, the current routine is terminated.

  Subsequently, a control operation at the time of engine start of the control device for an internal combustion engine of the present embodiment configured as described above will be described. FIG. 7 shows (a) opening and closing of the ignition switch (IG) 18 at the time of engine start of the internal combustion engine to which the control device of the present embodiment is applied, (b) the opening degree of the waste gate valve (WGV) 15, and ( c) An example of the transition of the engine speed is shown. In the figure, the opening / closing of the ignition switch 18 and the transition of the engine speed when the intermediate lock mechanism is activated at the start of the engine start are indicated by a one-dot chain line, and the transition when the intermediate lock mechanism is not activated are indicated by a solid line. It is shown.

  In an example of the control mode shown in FIG. 10, at time t0, the ignition switch 18 is turned on and the engine start is started. At this time, if the intermediate lock mechanism of the variable valve timing mechanism 10 is operating, the waste gate valve 15 is opened. As a result, exhaust gas flows directly into the catalytic converter 16 bypassing the exhaust turbine 14. Therefore, at this time, the temperature of the exhaust gas flowing into the catalytic converter 16 increases, and the warm-up property of the catalyst is improved.

  On the other hand, when the intermediate lock mechanism of the variable valve timing mechanism 10 is not operating at the start of engine start, the waste gate valve (WGV) 15 is closed. The exhaust at this time flows through the exhaust turbine 14. Therefore, due to the rotational resistance of the exhaust turbine 14, the flow resistance of the exhaust increases, and the back pressure of the internal combustion engine increases. As a result, the increase in the engine rotational speed becomes dull.

  Here, as shown in FIGS. 8A and 8C, when the engine speed NE is low, the cam torque fluctuation period is longer than when the engine speed NE is high. If the cam torque fluctuation period becomes longer, the rotation of the vane rotor 100 in the advance direction by the positive cam torque and the rotation of the vane rotor 100 in the retard direction by the negative cam torque continue for a longer time. . Therefore, as shown in FIGS. 2B and 2C, when the engine speed NE is low, the swinging amplitude of the vane rotor 100 due to the cam torque variation is larger than when the engine speed NE is high. growing. Therefore, if the waste gate valve 15 is closed to increase the back pressure of the internal combustion engine and the increase speed of the engine rotational speed is slowed, the oscillation amplitude of the vane rotor 100 accompanying the fluctuation of the cam torque is large after the start of the engine is started. It will continue longer. As a result, the vane rotor 100 is more quickly and reliably rotated to the intermediate lock phase.

According to the control apparatus for an internal combustion engine of the present embodiment described above, the following effects can be obtained.
(1) In the present embodiment, the waste gate valve 15 is opened when the intermediate lock mechanism of the variable valve timing mechanism 10 is operating at the start of engine start, and the waste gate valve 15 is opened when the intermediate lock mechanism is not operating. I have to. Therefore, when the intermediate lock mechanism is not in operation, the back pressure of the internal combustion engine is increased and the increase in the engine rotational speed is suppressed, and the swing amplitude of the vane rotor 100 is increased in accordance with the cam torque variation. Therefore, the self-rotation of the vane rotor 100 to the intermediate lock phase can be performed earlier and more reliably.

  (2) When the intermediate lock mechanism of the variable valve timing mechanism 10 is operating at the start of engine start, the exhaust gas bypasses the exhaust turbine 14 and flows directly into the catalytic converter 16, and the exhaust gas flowing into the catalytic converter 16 The temperature will increase. Therefore, at this time, the warm-up property of the catalyst can be improved.

  (3) When the intermediate lock mechanism of the variable valve timing mechanism 10 is operating at the start of engine start, the back pressure of the internal combustion engine is reduced and the speed of increase of the engine rotational speed is increased. Startup can be completed.

(Second Embodiment)
Hereinafter, a second embodiment of the control device for an internal combustion engine according to the present invention will be described in detail with reference to FIG. In the present embodiment, members having the same functions and configurations as those of the first embodiment are denoted by common reference numerals, and detailed description thereof is omitted.

  In the first embodiment, the waste gate valve 15 is opened to increase the back pressure of the internal combustion engine, so that the operation of the intermediate lock mechanism at the time of starting the engine can be performed earlier and more reliably. On the other hand, some turbochargers are provided with a variable nozzle that adjusts the flow rate of the exhaust gas blown to the exhaust turbine. In an internal combustion engine equipped with such a turbocharger with a variable nozzle, the back pressure of the internal combustion engine can be raised and lowered by controlling the opening of the variable nozzle. Therefore, in the present embodiment, the operability of the intermediate lock mechanism at the time of starting the engine is enhanced by controlling the opening degree of the variable nozzle of the turbocharger.

  Here, first, the configuration of the turbocharger with a variable nozzle will be described. As shown in FIG. 9, in this type of turbocharger, a plurality of variable nozzles 31 are arranged at equal intervals on the outer periphery of the exhaust turbine 30. The variable nozzles 31 are rotated in conjunction with each other, whereby the area of the exhaust passage formed between the adjacent variable nozzles 31 is changed. FIG. 4A shows a state when the variable nozzle 31 is closed, and FIG. 4B shows a state when the variable nozzle 31 is opened.

  In the present embodiment, the electronic control unit 17 is configured such that when the intermediate lock mechanism is not activated at the start of engine start, the flow rate of the exhaust gas blown to the exhaust turbine 30 is higher than when the intermediate lock mechanism is activated. The opening degree of the variable nozzle 31 is controlled. For example, when the intermediate lock mechanism is operated, the variable nozzle 31 is completely closed, and when the intermediate lock mechanism is not operated, the variable nozzle 31 is opened by a certain amount. Reduce the opening.

  Even in such a case, when the intermediate lock mechanism is not activated at the start of engine start, the flow resistance of the exhaust gas increases, the back pressure of the internal combustion engine increases, and the increase in engine speed is suppressed. Therefore, it is possible to increase the amplitude of the swing of the vane rotor 100 accompanying the cam torque variation, and to rotate the vane rotor 100 to the intermediate lock phase earlier and more reliably.

  When the intermediate lock mechanism is operating at the start of engine start, the flow rate of the exhaust gas blown to the exhaust turbine 30 is reduced, and the heat loss of the exhaust gas required for the rotation of the exhaust turbine 30 is reduced. The temperature of exhaust gas to be increased. Therefore, at this time, the warm-up property of the catalyst is improved. Further, when the intermediate lock mechanism is operated, the engine rotational speed increases at a high speed, so that the start of the internal combustion engine can be completed in a shorter time.

In addition, the said embodiment can also be changed and implemented as follows.
In the first embodiment, the waste gate valve 15 is closed when the intermediate lock mechanism is not operating at the start of engine start, and the waste gate valve 15 is opened when the intermediate lock mechanism is operating. When the opening degree of the waste gate valve 15 can be changed stepwise or continuously, the opening degree of the waste gate valve 15 is changed depending on whether or not the intermediate lock mechanism is activated at the start of engine start. An earlier and more reliable operation of the intermediate lock mechanism can be made possible at the time of engine start. That is, when the intermediate lock mechanism is not operating at the start of engine start, the flow rate of the exhaust gas that bypasses the exhaust turbine 14 is reduced by reducing the opening of the waste gate valve 15 compared to when it is operating. As a result, the back pressure of the internal combustion engine increases. Therefore, an increase in the engine rotation speed is suppressed, the amplitude of the swing of the vane rotor 100 due to the cam torque variation is increased, and the rotation of the vane rotor 100 to the intermediate lock phase can be performed earlier and more reliably. . In this case as well, when the intermediate lock mechanism is operating at the start of engine start, the flow rate of the exhaust gas that bypasses the exhaust turbine 14 is increased, and the temperature of the exhaust gas flowing into the catalytic converter 16 is increased. Warm-up performance is improved.

  In the above embodiment, the operability of the intermediate lock mechanism at the time of starting the engine is improved by increasing the flow resistance of the exhaust gas by controlling the opening degree of the waste gate valve 15 and the variable nozzle 31. Thus, even if the flow resistance of the exhaust is increased, the operability of the intermediate lock mechanism at the time of starting the engine can be improved. For example, a back pressure of the internal combustion engine is increased and a swing amplitude of the vane rotor 100 is increased by installing a valve that can change the flow area in the exhaust passage and reducing the opening degree. . Therefore, when the intermediate lock mechanism is not operated at the start of engine start, if the flow resistance of the exhaust gas in the exhaust passage of the internal combustion engine is larger than when it is operated, the intermediate lock mechanism at the time of engine start is increased. The operability of the lock mechanism can be improved. On the other hand, when the intermediate lock mechanism is operating at the start of engine start, the engine speed increases, so that the start of the internal combustion engine can be completed in a shorter time.

  In the above embodiment, the lock pin 106 and the spring 107 of the intermediate lock mechanism are also used as a ratchet mechanism. However, a ratchet mechanism having the same function is provided completely separately from the intermediate lock mechanism. May be.

  In the above embodiment, the variable valve timing mechanism 10 is provided with a ratchet mechanism in order to more reliably perform the self-rotation of the vane rotor 100 to the intermediate lock phase due to the swing of the vane rotor 100 due to the fluctuation of the cam torque. It was. Even if there is no such ratchet mechanism, the ratchet mechanism may be omitted as long as the vane rotor 100 can be independently rotated to the intermediate lock phase.

  In the above embodiment, the lock pin 106 is provided on the vane rotor 100 side and the lock hole 108 is provided on the housing 101 side. However, the lock hole is provided on the vane rotor 100 side and the lock pin is provided on the housing 101 side. An intermediate lock mechanism may be configured.

  In the above embodiment, the variable valve timing mechanism 10 is configured such that the vane rotor 100 rotates in synchronization with the camshaft and the housing 101 is drivingly connected to the crankshaft. Conversely, the variable valve timing mechanism 10 may be configured such that the housing 101 rotates synchronously with the camshaft and the vane rotor 100 is drivingly connected to the crankshaft.

The configuration of the variable valve timing mechanism 10 is not limited to that illustrated in the above embodiment, and may be changed as appropriate. In short, it has the following configurations (a) to (c), and the valve timing is variable through relative rotation between the first rotating body (b) below and the second rotating body (b) below. The present invention can be applied to any internal combustion engine provided with a variable valve timing mechanism.
(A) A first rotating body drivingly connected to the camshaft.
(B) A second rotating body that is coaxial with the first rotating body and is disposed so as to be relatively rotatable and is drivingly connected to the crankshaft.
(C) An intermediate lock mechanism that mechanically locks the relative rotation of the first and second rotating bodies in the middle of the relative rotation range of the first and second rotating bodies.

  DESCRIPTION OF SYMBOLS 1 ... Intake passage, 2 ... Air cleaner, 3 ... Turbocharger, 4 ... Compressor, 5 ... Intercooler, 6 ... Throttle valve, 8 ... Intake valve, 9 ... Combustion chamber, 10 ... Valve timing variable mechanism, 11 ... Exhaust valve, DESCRIPTION OF SYMBOLS 13 ... Exhaust passage, 14 ... Exhaust turbine, 15 ... Waste gate valve, 16 ... Catalytic converter, 17 ... Electronic control unit, 18 ... Ignition switch, 19 ... Crank angle sensor, 20 ... Cam angle sensor, 30 ... Exhaust turbine, 31 ... Variable nozzle, 100 ... Vane rotor (first rotating body), 101 ... Housing (second rotating body), 102 ... Vane, 103 ... Recess, 104 ... Advance oil chamber, 105 ... Delay oil chamber, 106 ... Lock pin (intermediate lock mechanism, ratchet mechanism), 107 ... Spring (intermediate lock mechanism, ratchet) Tsu DOO mechanism), 108 ... lock hole (intermediate lock mechanism), 109 ... ratchet groove (ratchet mechanism).

Claims (5)

A first rotating body that is drivingly connected to the camshaft, a second rotating body that is coaxially connected to the first rotating body and is rotatably arranged and is drivingly connected to the crankshaft; A variable valve timing mechanism that includes an intermediate lock mechanism that mechanically locks the relative rotation of the rotating bodies in the middle of the relative rotation range of the rotating bodies, and a waste gate that adjusts the flow rate of exhaust gas that bypasses the exhaust turbine In a control device for an internal combustion engine that controls an internal combustion engine comprising a turbocharger with a valve,
When the rotation of the rotating body is not locked by the intermediate lock mechanism at the start of engine starting, the waste gate valve is opened compared to when the rotation is locked at the start of engine starting. A control device for an internal combustion engine, characterized in that the degree is reduced. When the rotation of the rotating body is not locked by the intermediate lock mechanism when the engine is started, the waste gate valve is closed. When the lock is locked when the engine is started, the waste gate valve is The control device for an internal combustion engine according to claim 1, wherein the control device is opened. A first rotating body that is drivingly connected to the camshaft, a second rotating body that is coaxially connected to the first rotating body and is rotatably arranged and is drivingly connected to the crankshaft; With a variable valve timing mechanism that includes an intermediate lock mechanism that mechanically locks the relative rotation of the rotating bodies in the middle of the relative rotation range of the rotating bodies, and a variable nozzle that adjusts the flow rate of the exhaust blown to the exhaust turbine An internal combustion engine control device for controlling an internal combustion engine comprising:
When the relative rotation of the first and second rotating bodies is not locked by the intermediate lock mechanism at the start of engine starting, compared to when the locking is performed at the start of engine starting. The opening of the variable nozzle is controlled so that the flow rate of the exhaust gas to the exhaust turbine is increased. A first rotating body that is drivingly connected to the camshaft, a second rotating body that is coaxially connected to the first rotating body and is rotatably arranged and is drivingly connected to the crankshaft; In a control apparatus for an internal combustion engine that controls an internal combustion engine that includes a variable valve timing mechanism that includes an intermediate lock mechanism that mechanically locks the relative rotation of the rotating bodies in the middle of the relative rotation range of the rotating bodies.
When the rotation of the rotating body is not locked by the intermediate lock mechanism at the start of engine start, the exhaust of the internal combustion engine is less than when the lock is set at the start of engine start. A control apparatus for an internal combustion engine, wherein the flow resistance of exhaust gas in the passage is increased. The variable valve timing mechanism includes a ratchet mechanism that guides a phase of relative rotation of the first and second rotating bodies to a phase in which the relative rotation is locked by the intermediate lock mechanism. 5. The control device for an internal combustion engine according to any one of 4 above.