JP2004011591A - Valve timing control device for vehicular internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve timing control device for a vehicular internal combustion engine capable of suitably ensuring an engine starting property. <P>SOLUTION: The device is provided with a valve timing variable mechanism for changing a relative rotation phase in regard to a crankshaft about an intake cam shaft drive-coupled to the crankshaft. An extruding mechanism energizing to an advance angle side so as to make the relative rotation phase become a starting phase with advance angle from a maximum retard angle phase by specified amount is provided, and a starter motor forcibly rotation driving the crankshaft is provided. When the relative rotation phase of an intake cam shaft during stopping of an engine is a phase in retard angle side than the starting phase (a step S100 : YES), the starter motor is operated during a specified period (a step S103). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a valve timing control apparatus for an internal combustion engine for a vehicle, which variably controls an opening / closing timing (valve timing) of an engine valve that opens / closes according to a rotation phase of a camshaft.
[0002]
[Prior art]
Some internal combustion engines for vehicles are provided with a valve timing control device that appropriately changes the valve timing of the engine in order to improve output and emission. Such a valve timing control device includes, for example, a vane rotor connected to a camshaft of an internal combustion engine, and an advance side pressure chamber and a retard side pressure chamber provided so as to sandwich the vane rotor in the rotation direction of the camshaft. . Then, hydraulic oil is selectively supplied to each of the pressure chambers, and the vane rotor is moved by the pressure difference between the pressure chambers generated thereby, so that the relative rotation phase of the camshaft with respect to the crankshaft of the engine is advanced or shifted. Change to the retard side. By changing the relative rotational phase of the camshaft in this manner, the valve timing of the engine is changed.
[0003]
In recent years, such devices include a phase in which the relative rotation phase of the camshaft at the start of the start of the internal combustion engine is advanced by a predetermined amount from the control limit phase on the retard side (the most retarded phase) (hereinafter referred to as such phase). There is also known a device provided with a lock mechanism that mechanically locks the engine at the engine start phase (hereinafter, simply referred to as “start phase”). In such a device, usually, the valve timing at the start of the start of the internal combustion engine is fixed at a valve timing (start timing) suitable for engine start by the lock mechanism. Thus, when the relative rotation phase of the camshaft is fixed to the above-described starting phase by the lock mechanism, the valve timing can be held at the starting timing even if each pressure chamber is not filled with hydraulic oil. Therefore, if the engine is fixed by the lock mechanism at the time of starting the engine, good engine startability can be ensured.
[0004]
It should be noted that such a lock mechanism is normally configured to be able to be fixed when the hydraulic oil is drained from each pressure chamber, and to be released when each of the pressure chambers is filled with the hydraulic oil. Therefore, when each pressure chamber is filled with hydraulic oil during engine startup, the lock mechanism is unlocked, and the valve timing can be changed.
[0005]
In a valve timing control device provided with such a lock mechanism, the relative rotation phase of the camshaft is usually fixed in advance to the starting phase when the engine is stopped. Therefore, when the engine is stopped, the valve timing is changed so that the relative rotation phase of the camshaft matches the above-mentioned starting phase, and thereafter, the hydraulic oil is removed from each pressure chamber to fix the lock mechanism.
[0006]
However, it has been difficult to reliably displace the relative rotation phase of the camshaft to the starting phase when the engine is stopped for the following reasons.
First, in order to lock the lock mechanism, it is necessary to drain the hydraulic oil from each pressure chamber, but once the hydraulic oil is drained, the relative rotation phase of the camshaft is securely held at the above-mentioned starting phase. You will not be able to keep it. Therefore, when the lock mechanism is brought into the lockable state, the relative rotation phase of the camshaft may deviate from the above-mentioned starting phase, and locking may not be possible.
[0007]
In addition, a driving reaction force accompanying the depression of the valve by the cam acts on the rotating camshaft in the counter-rotating direction of the camshaft, that is, in the retard direction. Therefore, when the relative rotation phase of the camshaft is on the retard side of the starting phase just before the engine is stopped, the vane rotor connected to the camshaft is moved to the advance side against the driving reaction force. Needs to be displaced. However, when the engine is stopped, the engine speed is usually low, and the supply pressure of hydraulic oil from an oil pump driven based on the rotation of the crankshaft is also low. As a result, sufficient hydraulic oil cannot be supplied to the advance pressure chamber, and the advance speed of the valve timing decreases, and in some cases, the relative rotational phase of the camshaft is changed until the internal combustion engine is completely stopped. It may not be possible to advance to the starting phase.
[0008]
Therefore, conventionally, as a technique for more easily and reliably locking the engine at the starting phase advanced by a predetermined amount from the most retarded phase when the engine is stopped, for example, as disclosed in JP-A-2002-13402, Valve timing control devices have been proposed. In this valve timing control device, a spring is provided to bias the vane rotor in the advance side when the relative rotation phase of the camshaft is on the retard side from the start phase.
[0009]
In the valve timing control device provided with such a spring, when the relative rotation phase of the camshaft is on the retard side with respect to the starting phase, the vane rotor is urged to the advance side by the urging force of the spring. Become like Therefore, even if the relative rotational phase of the camshaft is on the retard side of the starting phase immediately before the engine is stopped, the urging force of the spring is assisted, and despite the lack of hydraulic oil supply pressure, The vane rotor can be relatively quickly displaced to the advance side.
[0010]
On the other hand, during the rotation of the camshaft, the vane rotor receives the action of the driving reaction force to the retard side as described above. Therefore, even if the relative rotation phase of the camshaft is on the advance side of the starting phase, the vane rotor is autonomously displaced to the retard side.
[0011]
Further, in the valve timing control device provided with the spring, even if the hydraulic oil is removed from each pressure chamber to lock the lock mechanism, the relative rotation phase of the camshaft is displaced toward the start phase. It will be like that.
[0012]
As described above, in the valve timing control device provided with the spring, the relative rotation phase of the camshaft can be reliably shifted to the starting phase when the engine is stopped, and good engine startability can be secured.
[0013]
[Problems to be solved by the invention]
However, even in such a valve timing control device, when the engine is suddenly stopped, such as when an engine is stalled due to an excessive load applied to the internal combustion engine, the starting of the relative rotation phase of the camshaft is started. The engine may be started without completing the displacement to the phase.
[0014]
Even in such a case, when the engine start is started and the crankshaft is forcibly rotated by the starter motor, the relative rotational phase of the camshaft is changed by the action of the biasing force of the spring and the driving reaction force of the valve. It gradually shifts to the starting phase. Therefore, although the internal combustion engine can be started, it is inevitable that the time required for the start becomes long.
[0015]
In particular, especially when the internal combustion engine is stopped when the outside air temperature is extremely low, such as in winter, and is left as it is, if the relative rotation phase of the camshaft is not at the above-described starting phase at the start of starting, the internal combustion engine is started. There is a possibility that the startability may be significantly deteriorated. In such a case, the operating oil at the time of starting the engine has a very low temperature and a very high viscosity. Therefore, even if the starter is operated to start the forced rotation drive of the crankshaft, the driving resistance of the vane rotor of the variable valve timing mechanism increases due to the high viscosity of the hydraulic oil, and the relative rotation phase of the camshaft cannot be displaced. There is a risk. In this case, the above-mentioned start timing cannot be obtained, and a remarkable decrease in engine startability cannot be avoided.
[0016]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a valve timing control device for an internal combustion engine for a vehicle, which can ensure the engine startability more appropriately.
[0017]
[Means for Solving the Problems]
Hereinafter, the means for achieving the above object and the effects thereof will be described.
First, the invention according to claim 1 selectively shifts a relative rotation phase of a camshaft, which is drivingly connected to a crankshaft of an internal combustion engine for a vehicle, with respect to the crankshaft to an advance pressure chamber and a retard pressure chamber. A variable valve timing mechanism for the internal combustion engine that changes to either the advance side or the retard side based on the pressure of the supplied fluid; and the relative rotation phase of the camshaft is advanced by a predetermined amount from the most retarded phase. A biasing means for biasing the vehicle toward the advanced angle so as to have an angled phase for starting the engine, and a valve timing control device for an internal combustion engine for a vehicle, comprising: driving means for forcibly driving the camshaft; The gist of the invention is that when the engine is stopped, the crankshaft is forcibly rotated by the driving means for a predetermined period.
[0018]
According to the above configuration, the camshaft and the crankshaft can be forcibly rotated together with the crankshaft when the engine is stopped, in which the viscosity of the fluid used for the operation of the variable valve timing mechanism is sufficiently reduced with the operation of the engine. Accordingly, even if the engine is stopped before the displacement of the relative rotation phase of the camshaft to the phase for starting the engine (starting phase) is completed, the biasing force of the biasing means and the driving reaction of the engine valve are stopped. By the action of the force, the relative rotational phase of the camshaft can be moved closer to the starting phase. Therefore, it is possible to effectively suppress the occurrence of a situation in which the engine starts in a state where the relative rotation phase of the camshaft is greatly shifted from the starting phase, and thus the engine startability is further improved. Can be secured.
[0019]
According to a second aspect of the present invention, in the valve timing control device for an internal combustion engine for a vehicle according to the first aspect, the vehicle further includes a lock unit that locks a relative rotation phase of the camshaft with a phase for starting the engine. That is the gist.
[0020]
According to the above configuration, the locking of the relative rotation phase of the camshaft by the locking means at the starting phase can be performed more reliably.
According to a third aspect of the present invention, in the valve timing control apparatus for an internal combustion engine for a vehicle according to the first or second aspect, the forcible rotation of the crankshaft is controlled by a relative rotation phase of the camshaft when the engine is stopped. Is executed on condition that the phase is not in the engine start phase.
[0021]
According to the above configuration, the forced rotation drive of the crankshaft is executed only when the relative rotation phase of the camshaft when the engine is stopped is not at the start phase, in other words, only when the forced rotation drive is required. Will be done. Therefore, it is possible to minimize the forced rotation of the crankshaft at unnecessary timing.
[0022]
According to a fourth aspect of the present invention, in the valve timing control device for a vehicle internal combustion engine according to the first or second aspect, the forcible rotation of the crankshaft is controlled by a relative rotation phase of the camshaft when the engine is stopped. Is executed only when the phase is on the retard side with respect to the engine start phase.
[0023]
According to the above configuration, it is possible to effectively suppress occurrence of a situation in which the engine is started in a state where the relative rotation phase of the camshaft is shifted to the retard side more greatly than the starting phase. Become.
[0024]
According to a fifth aspect of the present invention, in the valve timing control device for an internal combustion engine for a vehicle according to any one of the first to fourth aspects, the forced rotation drive of the crankshaft is stopped unintentionally by the internal combustion engine. The gist is that it is executed only when it is executed.
[0025]
According to the above configuration, the crankshaft is forcibly driven only when the internal combustion engine is stopped unintentionally, in other words, only when the relative rotation phase of the camshaft is likely to be significantly different from the starting phase. . For this reason, it becomes possible to suitably suppress the crankshaft from being forcibly rotated at unnecessary timing.
[0026]
The fact that the internal combustion engine was stopped unintentionally means that, when the engine is stopped, the power transmission system from the crankshaft to the wheels is in a transmission state, and the ignition switch is turned on. Can be determined.
[0027]
According to a seventh aspect of the present invention, in the valve timing control apparatus for a vehicle internal combustion engine according to any one of the first to sixth aspects, the forcible rotation drive of the crankshaft is performed by a power from the crankshaft to a wheel. The gist is that the execution is performed on condition that the transmission system is in the non-transmission state.
[0028]
According to the above configuration, the crankshaft is prevented from being forcibly rotated when the power transmission system is in the transmission state. For this reason, the forced rotation drive of the crankshaft can be appropriately performed.
[0029]
According to an eighth aspect of the present invention, in the valve timing control apparatus for an internal combustion engine for a vehicle according to the seventh aspect, the driving means forcibly drives the crankshaft based on power supply. When the power transmission system is not in the non-transmission state for a predetermined time after the internal combustion engine is stopped, the power supply to the drive unit is interrupted.
[0030]
According to the above configuration, since the power transmission system does not enter the non-transmission state, it is possible to prevent the power supply to the drive unit from being maintained unnecessarily for a long time after the internal combustion engine is stopped, and Waste can be suitably suppressed.
[0031]
According to a ninth aspect of the present invention, in the valve timing control apparatus for an internal combustion engine for a vehicle according to any one of the first to eighth aspects, the relative rotational phase of the camshaft when the engine is stopped is defined as an engine rotational speed. Is the phase detected last in the detection history of the relative rotation phase when the rotation speed is equal to or higher than the predetermined rotation speed.
[0032]
Normally, when the engine rotation speed is extremely reduced, it becomes difficult to detect the relative rotation phase of the camshaft. In this regard, according to the above configuration, the relative rotation phase of the camshaft detected satisfactorily when the engine rotation speed is sufficiently high, and the phase detected last in the detection history, that is, the engine stop most The phase close to the phase at the time can be used as the relative rotation phase of the camshaft when the engine is stopped.
[0033]
According to a tenth aspect of the present invention, in the valve timing control apparatus for a vehicle internal combustion engine according to any one of the first to ninth aspects, when the crankshaft is forcibly driven to rotate, fuel is injected into the internal combustion engine. The gist is that both the operation and the ignition operation for the same fuel are stopped.
[0034]
According to the above configuration, during the forced rotation drive of the crankshaft, it is possible to omit operations unnecessary for moving the relative rotation phase of the camshaft, such as fuel injection operation and ignition operation for the fuel.
[0035]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a valve timing control device for a vehicle internal combustion engine according to the present invention will be described with reference to FIGS.
[0036]
First, a schematic configuration of an internal combustion engine to which the valve timing control device according to the present embodiment is applied and peripheral devices thereof will be described with reference to FIG.
As shown in FIG. 1, a cylinder block 11a of the internal combustion engine 11 is provided with a piston 12 (only one is shown in FIG. 1) for each cylinder so as to be able to reciprocate. This piston 12 is connected via a connecting rod 13 to a crankshaft 14 which is an output shaft of the internal combustion engine 11. The reciprocating movement of the piston 12 is converted into rotation of the crankshaft 14 by the connecting rod 13.
[0037]
A cylinder head 15 is attached to the cylinder block 11a so as to cover an upper part thereof. A combustion chamber 16 is defined between the cylinder head 15 and the piston 12 in the cylinder. An intake port 17 and an exhaust port 18 provided in the cylinder head 15 are connected to the combustion chamber 16. An intake passage 25 communicates with the intake port 17, and an exhaust passage 26 communicates with the exhaust port 18. Further, the intake port 17 is provided with an intake valve 19, and the exhaust port 18 is provided with an exhaust valve 20.
[0038]
The cylinder head 15 rotatably supports an intake camshaft 21 for opening and closing the intake valve 19 and an exhaust camshaft 22 for opening and closing the exhaust valve 20. The rotation of the crankshaft 14 is transmitted to the intake and exhaust camshafts 21 and 22 via gears and chains. Then, when the intake camshaft 21 rotates, the intake valve 19 is driven to open and close, and the intake port 17 and the combustion chamber 16 are communicated and shut off. Further, when the exhaust camshaft 22 rotates, the exhaust valve 20 is driven to open and close, and the exhaust port 18 and the combustion chamber 16 are communicated and shut off.
[0039]
In the internal combustion engine 11, the intake camshaft 21 is provided with a variable valve timing mechanism 24 for varying the opening / closing timing (valve timing) of the intake valve 19 of the engine 11. The specific structure of the variable valve timing mechanism 24 will be described later in detail.
[0040]
On the other hand, a fuel injection valve 27 for injecting fuel into the intake port 17 is provided at a downstream end of the intake passage 25. The fuel injection valve 27 injects fuel into the intake port 17 to form a mixture of fuel and air when air in the intake passage 25 is sucked into the combustion chamber 16 during an intake stroke of the internal combustion engine 11. .
[0041]
Further, the cylinder head 15 is provided with an ignition plug 28 for igniting the air-fuel mixture filled in the combustion chamber 16. The ignition plug 28 performs an ignition operation based on an operation signal output from the igniter 28a. Then, when the air-fuel mixture in the combustion chamber 16 is ignited and the air-fuel mixture burns, the combustion energy causes the piston 12 to reciprocate, the crankshaft 14 to rotate, and the internal combustion engine 11 to be driven. The air-fuel mixture burned in the combustion chamber 16 is sent out to the exhaust passage 26 as exhaust by the rise of the piston 12 during the exhaust stroke of the internal combustion engine 11.
[0042]
Further, the internal combustion engine 11 is provided with a starter motor 32 as driving means for forcibly driving the crankshaft 14.
On the other hand, the device of the present embodiment includes an ignition (IG) switch 29 and a main relay 30 that switch between supplying (ON) and interrupting (OFF) power to the internal combustion engine 11 and its peripheral devices. Specifically, the internal combustion engine 11 and its peripheral devices are connected to the battery 31 via the IG switch 29 and the main relay 30. Thus, power is supplied to the internal combustion engine 11 and its peripheral devices from the battery 31 only when at least one of the IG switch 29 and the main relay 30 is turned on.
[0043]
Further, the device of the present embodiment is provided with the following various sensors and the like in order to detect the operating state of the vehicle or the internal combustion engine 11. That is, a vehicle speed sensor 33 for detecting the traveling speed of the vehicle is provided near the wheels (not shown). The internal combustion engine 11 is connected to an automatic transmission (not shown) for switching the shift mode of the vehicle. The automatic transmission is provided with a shift position sensor 34 for detecting the shift position (shift position). Have been. The shift position sensor 34 mainly detects whether the shift position of the automatic transmission is in the N (neutral) range or the D (drive) range. That is, it detects that the automatic transmission is not transmitting power or that power is being transmitted.
[0044]
Further, a crank angle sensor 35 including an electromagnetic pickup is provided near a pulser provided on the crankshaft 14 of the internal combustion engine 11. In the vicinity of the pulsar provided on the intake camshaft 21, there is provided a cam angle sensor 36 also formed of an electromagnetic pickup. In the present embodiment, the engine rotation speed, the crank angle, the cam angle, and the relative rotational phase of the intake camshaft 21 with respect to the crankshaft 14 are calculated based on the pulse signals output from the sensors 35 and 36.
[0045]
Further, the device of the present embodiment includes an electronic control device 37 including, for example, a microcomputer or the like. The electronic control unit 37 takes in the detection signals of the various sensors, and according to the operating states of the vehicle and the internal combustion engine 11 determined based on the detection signals, the variable valve timing mechanism 24, the fuel injection valve 27, The ignition plug 28 (igniter 28a), the starter motor 32, the main relay 30, and the like are controlled.
[0046]
Next, a specific configuration of the variable valve timing mechanism 24 will be described with reference to FIG.
FIG. 2 shows a schematic configuration of the variable valve timing mechanism 24 and its peripheral devices according to the present embodiment.
[0047]
As shown in FIG. 2, the journal 21 a of the intake camshaft 21 to which the variable valve timing mechanism 24 is attached is rotatably supported by the bearing 15 a of the cylinder head 15. The variable valve timing mechanism 24 includes a gear 24 a to which the rotation of the crankshaft 14 is transmitted via a chain or the like, and a rotor 41 fixed to a tip end surface of the intake camshaft 21 by a bolt 42. The gear 24a is relatively rotatable with respect to the intake camshaft 21 penetrating the center thereof.
[0048]
A ring cover 44 provided so as to surround the rotor 41 is in contact with a front end surface (the left side surface in FIG. 2) of the gear 24a, and a front end opening of the ring cover 44 is closed by a closing plate 45. . The gear 24a, the ring cover 44, and the closing plate 45 are fixed so as to be integrally rotatable by bolts 46. Therefore, the intake camshaft 21 and the rotor 41 can rotate integrally about the axis L of the shaft 21. On the other hand, the gear 24a, the ring cover 44, and the closing plate 45 are relatively rotatable about the axis L. It is rotatable.
[0049]
Fluid (hydraulic oil) is selectively supplied to the variable valve timing mechanism 24 from the advance-side oil passage 47 and the retard-side oil passage 48 formed as shown in the bearing portion 15a, the intake camshaft 21, and the like. You. When the variable valve timing mechanism 24 is operated by supplying the hydraulic oil in this manner, the relative rotation phase of the intake camshaft 21 with respect to the crankshaft 14 is changed to the advance side or the retard side, and the valve timing of the intake valve 19 is changed. Will be done.
[0050]
The advance-side oil passage 47 and the retard-side oil passage 48 are connected to an oil control valve (OCV) 49. The supply passage 50 and the discharge passage 51 are connected to the OCV 49. The supply passage 50 is connected to an oil pan 11c provided below the internal combustion engine 11 via an oil pump 52 driven by the rotation of the crankshaft 14, and the discharge passage 51 is directly connected to the oil pan 11c. ing.
[0051]
The OCV 49 includes a spool 63 having four valve portions 64 and urged in opposite directions by a coil spring 62 and an electromagnetic solenoid 65, respectively. When the electromagnetic solenoid 65 is in the demagnetized state, the spool 63 is disposed at one end (the right side in FIG. 2) by the urging force of the coil spring 62. At this time, the advance-side oil passage 47 communicates with the supply passage 50, and the retard-side oil passage 48 communicates with the discharge passage 51. In this case, the hydraulic oil in the oil pan 11c is sent out by the oil pump 52 to the advance-side oil passage 47, and the hydraulic oil in the retard-side oil passage 48 is returned to the oil pan 11c.
[0052]
On the other hand, when the electromagnetic solenoid 65 is excited, the spool 63 is disposed at the other end (left side in FIG. 2) against the urging force of the coil spring 62. At this time, the advance-side oil passage 47 communicates with the discharge passage 51, and the retard-side oil passage 48 communicates with the supply passage 50. In this case, the hydraulic oil in the oil pan 11c is sent out to the retard oil passage 48 by the oil pump 52, and the hydraulic oil in the advance oil passage 47 is returned to the oil pan 11c.
[0053]
The control of the OCV 49 (electromagnetic solenoid 65) is also executed by the electronic control unit 37.
Next, a detailed structure of the rotor 41 and the ring cover 44 in the variable valve timing mechanism 24 will be described with reference to FIG.
[0054]
FIG. 3 shows a cross-sectional structure of the variable valve timing mechanism 24 according to the present embodiment along a direction perpendicular to the axis L of the intake camshaft 21.
[0055]
As shown in FIG. 3, on the inner peripheral surface 44a of the ring cover 44, four projecting portions 66 projecting toward the axis L of the intake camshaft 21 (FIG. 2) are provided in the circumferential direction of the ring cover 44. It is formed at predetermined intervals. Grooves 67 are formed between the overhangs 66 at predetermined intervals in the circumferential direction of the ring cover 44. Further, the rotor 41 includes four vanes 68a to 68d protruding outward so as to be inserted into the respective groove portions 67 from the outer peripheral surface thereof. Each of the grooves 67 into which the vanes 68a to 68d are inserted is divided into an advance pressure chamber 69 and a retard pressure chamber 70 by the vanes 68a to 68d. The advance pressure chamber 69 and the retard pressure chamber 70 are located so as to sandwich the vanes 68 a to 68 d from both sides in the circumferential direction of the rotor 41. The advance side oil passage 47 formed so as to pass through the inside of the rotor 41 communicates with the advance side pressure chamber 69, and the retard side oil passage 48 is formed so as to pass through the inside of the gear 24a. Further, the retard side oil passage 48 communicates.
[0056]
In such a variable valve timing mechanism 24, when the electromagnetic solenoid 65 of the OCV 49 is demagnetized, hydraulic oil is supplied from the advance-side oil passage 47 to the advance-side pressure chamber 69, and the retard-side pressure chamber 70 is supplied. The hydraulic oil is discharged from the oil passage via the retard side oil passage 48. As a result, the relative movement of the vanes 68a to 68d in the direction of the arrow A causes the rotor 41 to relatively rotate in the direction of the arrow A, whereby the relative rotational phase of the intake camshaft 21 with respect to the gear 24a (crankshaft 14) is increased. Is changed. Incidentally, in the variable valve timing mechanism 24, when the rotation of the crankshaft 14 is transmitted to the gear 24a via a chain or the like, both the gear 24a and the intake camshaft 21 rotate in the direction of arrow A. Accordingly, when the relative movement of each of the vanes 68a to 68d in the direction of the arrow A is performed, the intake camshaft 21 is advanced with respect to the crankshaft 14, and as a result, the valve timing of the intake valve 19 is also advanced. become.
[0057]
On the other hand, when the electromagnetic solenoid 65 of the OCV 49 is excited, hydraulic oil is supplied from the retard side oil passage 48 to the retard side pressure chamber 70 and from the advance side pressure chamber 69 via the advance side oil passage 47. Hydraulic fluid is discharged. As a result, the relative movement of the vanes 68a to 68d in the direction opposite to the arrow A causes the rotor 41 to relatively rotate in the direction opposite to the arrow A, whereby the intake camshaft 21 with respect to the gear 24a (the crankshaft 14) is rotated. Is changed in a direction opposite to the above. That is, in this case, the intake camshaft 21 is retarded with respect to the crankshaft 14, and as a result, the valve timing of the intake valve 19 is also retarded.
[0058]
Further, by controlling the applied voltage to the electromagnetic solenoid 65 and adjusting its exciting force, the spool 63 is arranged at an arbitrary position between the position in the demagnetized state and the position in the excited state. The supply and discharge amount of the hydraulic oil in each of the pressure chambers 69 and 70 can be adjusted according to the position where the pressure is set. Further, by adjusting the supply and discharge amount of the hydraulic oil, the relative rotational phase of the intake camshaft 21 can be fixed by adjusting the hydraulic oil in both the pressure chambers 69 and 70 to an appropriate pressure.
[0059]
Therefore, the duty of the voltage applied to the electromagnetic solenoid 65 is controlled to control the supply of hydraulic oil to the advance side pressure chamber 69 and the retard side pressure chamber 70, so that the valve timing of the intake valve 19 can be changed or a predetermined value can be obtained. It becomes possible to fix the timing.
[0060]
However, at the start of the start of the internal combustion engine 11, since the operating oil has been released from the advance side pressure chamber 69 and the retard side pressure chamber 70, the supply of the operating oil to the pressure chambers 69 and 70 starts. It takes some time before the valve timing can be actually controlled or fixed. Therefore, in the device of the present embodiment, the valve timing of the intake valve 19 is set to start the internal combustion engine 11 by the pushing mechanism 53 and the lock mechanism 76 described later until a certain time has elapsed since the start of the internal combustion engine 11. The timing is maintained at an appropriate timing (start timing). In the following description, the relative rotation phase of the camshaft 21 when the valve timing of the intake valve 19 is maintained at the start timing is referred to as “start phase”.
[0061]
Hereinafter, specific structures of the pushing mechanism 53 and the lock mechanism 76 will be described.
Here, first, a specific structure of the pushing mechanism 53 will be described.
[0062]
The pushing mechanism 53 functions as urging means for urging the relative rotation phase of the intake camshaft 21 to be the starting phase.
As shown in FIG. 3, two of the vanes 68 a to 68 d of the rotor 41 are respectively provided with an extruding mechanism 53 so as to be symmetric with respect to the axis L. These push-out mechanisms 53 urge the vanes 68b, 68d to the advanced side so that the relative rotational phase of the intake camshaft 21 becomes a phase advanced by a predetermined amount from the most retarded phase (the starting phase). It is for doing. Each of the pushing mechanisms 53 includes a push pin 55 that is urged by a coil spring 54 that expands and contracts in the circumferential direction and projects into the advance pressure chamber 69. When the distal end of the push pin 55 is in contact with the inner surface of the advance pressure chamber 69, the rotor 41 is urged to the advance side (the arrow A side in FIG. 3) by the coil spring 54. Become like
[0063]
The urging force of the coil spring 54 is set so that the following torques Tk, Tr, and Tf satisfy the relationship represented by the following equation (1).
Tk <Tf <(Tk + Tr) (1)
Here, each of the torques Tk, Tr, and Tf has the following torque in a state where the valve timing of the intake valve 19 is near the most retarded angle and the coil spring 54 is contracted.
Torque Tk: an average rotational torque that is an average value of rotational torque acting on the intake camshaft 21 as a reaction force when the intake camshaft 21 is rotated to open and close the intake valve 19. This torque Tk acts on the intake camshaft 21 in a direction opposite to the rotational direction, that is, a direction for displacing the relative rotational phase to the retard side.
Torque Tr: a hydraulic torque that acts on the intake camshaft 21 based on the pressure of the hydraulic oil when supplying hydraulic oil to the retard pressure chamber 70 to change the valve timing of the intake valve 19 to the retard side. This torque Tr also acts in the anti-rotation direction of the intake camshaft 21.
-Torque Tf: biasing torque acting on the intake camshaft 21 based on the biasing force of the coil spring 54. This torque Tf acts in the direction of rotation of the intake camshaft 21, that is, in the direction of displacing the relative rotational phase to the advance side.
[0064]
FIG. 4 exemplifies how the torques Tk, Tr and Tf change with respect to changes in the valve timing of the intake valve 19. In FIG. 4, the urging torque Tf is indicated by a solid line L1, the average rotation torque Tk is indicated by a broken line L2, and the sum of the average rotation torque Tk and the hydraulic torque Tr (“Tk + Tr”) is indicated by a broken line L3. I have.
[0065]
With such a setting of the coil spring 54, in the valve timing region where the urging force of the coil spring 54 acts, if the hydraulic oil is supplied to the retard pressure chamber 70 to generate the hydraulic torque Tr, the hydraulic torque Tr is increased. The sum of the acting hydraulic torque Tr and the average rotation torque Tk exceeds the urging torque Tf acting on the advance side. In the valve timing region, if the hydraulic oil is discharged from the retard pressure chamber 70 and the hydraulic torque Tr is set to “0”, the average rotational torque Tk acting on the retard side at that time is shifted to the advance side. The acting urging torque Tf is set to exceed. Therefore, even in the valve timing region where the urging force of the coil spring 54 acts, the relative rotation phase of the intake camshaft 21 can be reliably displaced to both the advance side and the retard side.
[0066]
In the present embodiment, when the relative rotational phase of the intake camshaft 21 is displaced from the most retarded phase to the advanced side, the intake valve when the urging force of the coil spring 54 becomes exactly “0” The nineteenth valve timing is the above-mentioned starting timing suitable for starting the internal combustion engine. Therefore, in the intake valve 19 of the present embodiment, the limit on the retard side of the control range of the valve timing is set further on the retard side than the start timing, and the range of the valve timing of the intake valve 19 that can be changed is further increased. The area is extended to the retard side.
[0067]
By the way, in the present embodiment, near the limit on the retard side of the control range of the valve timing as described above, the closing timing of the intake valve 19 can be delayed until during the compression stroke. Therefore, in such a valve timing region, it is possible to operate the internal combustion engine in the Atkinson cycle.
[0068]
Next, a specific structure of the lock mechanism 76 will be described with reference to FIG. FIG. 5 shows a cross-sectional structure of the lock mechanism 76 shown in FIG.
[0069]
The lock mechanism 76 functions as a lock unit that locks the relative rotation phase of the intake camshaft 21 when the valve timing is the start timing.
As shown in FIG. 5, the lock mechanism 76 includes a lock pin 78 provided on the vane 68c and urged toward the gear 24a by the coil spring 80, and a tip of the lock pin 78 provided on the gear 24a. And a hole 79 to be formed.
[0070]
The lock pin 78 and the coil spring 80 are disposed in a housing hole 81 formed in the vane 68c. A flange 78 a is formed on the outer peripheral surface of the lock pin 78, and an oil chamber 82 is defined by the flange 78 a at a position near the tip of the lock pin 78 in the accommodation hole 81. The oil chamber 82 communicates with the retard pressure chamber 70 via a passage 83, and hydraulic oil is supplied from the retard pressure chamber 70.
[0071]
On the other hand, an oil chamber 84 is formed at the bottom of the hole 79 into which the tip of the lock pin 78 is inserted. The oil chamber 84 communicates with the advance pressure chamber 69 via a passage 85, and hydraulic oil is supplied from the advance pressure chamber 69.
[0072]
The lock mechanism 76 adjusts the relative position of the intake camshaft 21 according to the pressure of the hydraulic oil supplied to the advance pressure chamber 69 and the retard pressure chamber 70, that is, the oil pressure in the pressure chambers 69 and 70. The rotation phase is fixed and released.
[0073]
That is, when the hydraulic oil is supplied to the retard pressure chamber 70 during the start of the internal combustion engine 11, the hydraulic pressure in the oil chamber 82 of the lock mechanism 76 increases accordingly. When the force acting on the lock pin 78 based on the hydraulic pressure becomes larger than the urging force of the coil spring 80, the lock pin 78 is pulled out of the hole 79. As a result, the lock of the relative rotation phase of the intake camshaft 21 by the lock mechanism 76 is released, and the valve timing control of the intake valve 19 becomes executable.
[0074]
On the other hand, during the operation of the internal combustion engine 11, the hydraulic pressure of at least one of the advance side pressure chamber 69 and the retard side pressure chamber 70 is increased. Therefore, the lock pin 78 is kept out of the hole 79 against the urging force of the coil spring 80 by the oil pressure of at least one of the oil chambers 82 and 84. That is, during the operation of the internal combustion engine 11, the lock mechanism 76 maintains the relative rotational phase (valve timing of the intake valve 19) of the intake camshaft 21 fixed on the advance side and the retard side. You.
[0075]
On the other hand, in the process of stopping the internal combustion engine 11, when the rotation speed of the crankshaft 14 gradually decreases, the amount of hydraulic oil sent to the variable valve timing mechanism 24 by the oil pump 52 gradually decreases, and each vane of the rotor 41 The hydraulic pressure acting on 68a-68d also gradually decreases. In a state where the oil pressure is reduced, the relative rotational phase of the intake camshaft 21 is set so that the valve timing of the intake valve 19 becomes the start timing by the rotational torque acting on the intake camshaft 21 or the urging torque Tf. Is displaced to the advance side or the retard side.
[0076]
When the oil pressure in the retard pressure chamber 70 becomes sufficiently low, the relative rotation phase of the intake camshaft 21 is maintained at a phase corresponding to the start timing by the urging force of the coil spring 54. Further, in this state, when the force acting on the lock pin 78 based on the oil pressure of the oil chambers 82 and 84 becomes smaller than the urging force of the coil spring 80, the lock pin 78 is inserted into the hole 79 by the urging force. As a result, the pin 78 and the hole 79 are engaged. That is, the valve timing of the intake valve 19 is fixed at the start timing. When the internal combustion engine 11 stops after the lock pin 78 is inserted into the hole 79, the valve timing of the intake valve 19 is reliably held at the start timing at the start of the next start of the internal combustion engine 11.
[0077]
In the valve timing control device according to the present embodiment, in order to reliably fix the relative rotation phase of the intake camshaft 21 by the lock mechanism 76, the valve timing control target position during the idling operation of the internal combustion engine 11 is set. , At a position corresponding to the start timing. Thus, when the internal combustion engine 11 is stopped according to the normal procedure, the valve timing of the intake valve 19 is securely fixed at the start timing through the pushing mechanism 53 and the lock mechanism 76, and then the internal combustion engine 11 is stopped. I am trying to. Note that the normal procedure is a procedure in which the IG switch 29 is turned off in a state where the internal combustion engine 11 is in an idle operation state after the vehicle stops.
[0078]
However, even in the apparatus according to the present embodiment, if the internal combustion engine 11 is stopped unintentionally due to an excessive load or the like, the relative rotation phase of the intake camshaft 21 becomes the phase corresponding to the start timing. The engine 11 may stop before reaching the (starting phase).
[0079]
In such a case, especially when the internal combustion engine 11 is stopped when the relative rotation phase of the intake camshaft 21 is at a position on the retard side with respect to the starting phase, the engine 11 When starting, an appropriate compression effect in the compression stroke cannot be obtained.
[0080]
Further, as described above, particularly in such a case, when the outside air temperature is extremely low, such as in winter, the internal combustion engine 11 is stopped and left as it is. The increase in viscosity inevitably causes a decrease in engine startability.
[0081]
Here, as described above, when the crankshaft 14 is forcibly driven immediately after the stop of the internal combustion engine 11 in which the temperature of the hydraulic oil is high and the viscosity thereof is sufficiently low, the relative rotational phase of the intake camshaft 21 becomes as described above. The biasing force of the coil spring 54 constituting a part of the push-out mechanism 53 gradually displaces to the advance side. This is specifically for the following reason.
[0082]
In the variable valve timing mechanism 24, a gear 24 a is drivingly connected to the crankshaft 14, while a rotor 41 rotatably provided relative to the gear 24 a is fixed to the intake camshaft 21. Therefore, when the internal combustion engine 11 is stopped, the rotation of the gear 24 a is restricted by the crankshaft 14, and the rotation of the rotor 41 is restricted by the intake camshaft 21. Further, the coil spring 54 does not have an urging force enough to rotate the crankshaft 14 and the intake camshaft 21 when the internal combustion engine 11 is stopped. Therefore, although the urging force of the coil spring 54 is acting, the relative rotational phase of the intake camshaft 21 is not autonomously displaced unless the crankshaft 14 is rotated.
[0083]
On the other hand, when the operation of the starter motor 32 is started when the internal combustion engine 11 is started, the crankshaft 14 is forcibly driven to rotate, and accordingly, the intake camshaft 21 is also forcibly driven. In addition, although the crankshaft 14 is forcibly rotated by the starter motor 32, a pressure of the hydraulic oil that is high enough to displace the relative rotation phase of the intake camshaft 21 has not yet been generated. Therefore, the torques Tk and Tf acting on the intake camshaft 21 at this time satisfy the following expression (2).
Tk <Tf ... (2)
Therefore, at this time, the relative rotational phase of the intake camshaft 21 gradually shifts to the advance side by the urging torque Tf generated by the urging force of the coil spring 54.
[0084]
Therefore, in the device of the present embodiment, taking into account such circumstances, when the relative rotation phase of the intake camshaft 21 when the internal combustion engine 11 is stopped is a phase that is more retarded than the start phase, the starter motor 32 Is operated for a predetermined time α (for example, 6 seconds). During the period in which the operation of the starter motor 32 is performed, the “on” state of the main relay 30 is maintained. As the predetermined time α, by operating the starter motor 32 when the internal combustion engine 11 is stopped, the relative rotation phase of the intake camshaft 21 is advanced to a phase at which good engine startability is obtained. Is set after being determined by experiments or the like.
[0085]
As a result, immediately after the engine is stopped, the viscosity of the hydraulic oil has been sufficiently reduced by the operation of the internal combustion engine 11, the crankshaft 14 is forcibly driven to rotate, and the relative rotational phase of the intake camshaft 21 is applied by the coil spring 54. The force is shifted to the advance side by the force torque Tf. Therefore, even when the internal combustion engine 11 is stopped without performing the normal stop procedure as described above, the fixing by the lock mechanism 76 can be completed. Alternatively, the relative rotational phase of the intake camshaft 21 can be displaced toward the side where the valve timing of the intake valve 19 approaches the start timing even before the fixing is completed. Thus, the occurrence of a situation in which the internal combustion engine 11 starts to start while the relative rotation phase of the intake camshaft 21 remains largely shifted to the retard side from the start phase is effectively suppressed. become.
[0086]
Further, in the device of the present embodiment, the operation of the starter motor 32 is executed only when the following conditions (a) and (b) are both satisfied.
[0087]
Condition (a): the internal combustion engine 11 is stopped unintentionally. Specifically, all of the following conditions must be satisfied.
-The shift position of the automatic transmission is in the D range.
-The IG switch 29 is "ON".
-The internal combustion engine 11 has stopped (the pulse signal has not been output from the crank angle sensor 35 for a predetermined time).
[0088]
Condition (b): After the condition (a) is satisfied, the shift position of the automatic transmission is operated to the N range.
The condition (a) is satisfied when the internal combustion engine 11 is stopped without performing a normal procedure. By setting the satisfaction of the condition (a) as a necessary condition for the execution of the forced rotation drive, when there is a possibility that the internal combustion engine 11 may be stopped with the intake valve 19 at an inappropriate valve timing for starting the engine. Only in this case, the starter motor 32 is operated.
[0089]
Further, by setting the condition (b) as a necessary condition for performing the above-described processing, the crankshaft 14 is forcibly rotated on the condition that the power transmission system from the crankshaft 14 to the wheels is in a non-transmission state. Become like
[0090]
Further, in the device of the present embodiment, even if the above condition (a) is satisfied, the above condition (b) is required until the elapsed time from the stop of the internal combustion engine 11 reaches a predetermined time β (for example, 5 minutes). Is not established, the main relay 30 is turned off. As a result, the shift position of the automatic transmission is not operated to the N range (the condition (b) is not satisfied), so that the “ON” state of the main relay 30 is maintained unnecessarily for a long time after the engine is stopped. Is prevented.
[0091]
In addition, in the device of the present embodiment, when the starter motor 32 is operated, both the injection operation by the fuel injection valve 27 and the ignition operation by the spark plug are forcibly stopped.
[0092]
In the present embodiment, the “relative rotational phase of the intake camshaft 21 when the internal combustion engine 11 is stopped” is, specifically, the relative rotational phase calculated when the engine rotational speed is equal to or higher than a predetermined rotational speed. The phase calculated last among the rotation phases is used. This is for the following reason.
[0093]
The relative rotational phase of the intake camshaft 21 with respect to the crankshaft 14 is calculated from the phase difference between the crank angle detected by the crank angle sensor 35 and the cam angle detected by the cam angle sensor 36. In the crank angle sensor 35 and the cam angle sensor 36, if the engine speed is extremely reduced, it is difficult to detect the crank angle and the cam angle with high accuracy.
[0094]
Therefore, by setting the rotation speed range defined by the predetermined rotation speed to a rotation speed range equal to or higher than the engine rotation speed N1 (for example, 400 rotations / minute) at which the crank angle and the cam angle can be properly detected, Is used only as the "relative rotation phase of the intake camshaft 21 when the internal combustion engine 11 is stopped". In particular, the last detected relative rotational phase of the relative rotational phases thus well calculated, that is, the relative rotational phase calculated at the timing closest to the timing at which the internal combustion engine 11 stops, is determined by the “internal combustion engine 11 At the time of stop, the relative rotational phase of the intake camshaft 21 ".
[0095]
Hereinafter, the processing procedure of the process of operating the starter motor 32 when the internal combustion engine 11 is stopped will be described in detail with reference to the flowchart shown in FIG. A series of processes shown in this flowchart are repeatedly executed by the electronic control unit 37 at a predetermined cycle.
[0096]
In this process, first, it is determined whether or not each of the following conditions is satisfied (step S100).
-The internal combustion engine 11 was stopped unintentionally (the above condition (a) was satisfied).
-The relative rotation phase of the intake camshaft 21 is a phase that is more retarded than the starting phase.
[0097]
If it is determined that any one of these conditions is not satisfied (step S100: NO), it is determined that there is no need to execute the operation of the starter motor 32, and this process is temporarily ended. Incidentally, even when the internal combustion engine 11 is stopped unintentionally, if the relative rotation phase of the intake camshaft 21 is on the advance side of the starting phase, the above-described engine stop is intentionally stopped. The operation of the starter motor 32 need not be performed. Therefore, in that case, the main relay 30 is turned off at an appropriate timing through a separate process.
[0098]
On the other hand, if it is determined that both of these conditions are satisfied (step S100: YES), it is determined that the starter motor 32 needs to be operated, and the execution flag is turned on (step S101). This execution flag is a flag that is turned off each time the internal combustion engine 11 is started, and the operation state is referred to in the next process (step S102).
[0099]
Thereafter, it is determined whether a condition for starting the operation of the starter motor 32 is satisfied (step S102). Specifically, it is determined whether the condition (b) and the following conditions (c) to (e) are all satisfied.
[0100]
Condition (c): The operation continuation time of the starter motor 32 is shorter than a predetermined time α.
Condition (d): the execution flag is turned on.
[0101]
Condition (e): the vehicle is stopped.
Here, if any one of the conditions (b), (d), and (e) is not satisfied, the environment for executing the operation of the starter motor 32 at the time of the engine stop as described above is sufficient. Judge that it is not in place. If the condition (c) is not satisfied, it is determined that the operation of the starter motor 32 when the engine is stopped has already been sufficiently performed. Then, when any of these determinations is made (step S102: NO), the electronic control unit 37 shifts to the processing of step S104 without operating the starter motor 32 (without executing the processing of step S103). I do.
[0102]
Therefore, in the present embodiment, after the unintended stop of the internal combustion engine 11, the operation of the starter motor 32 is continued until the execution conditions shown in the above conditions (b), (d) and (e) are satisfied. It will not be started.
[0103]
Then, after all of these conditions (b) to (e) are satisfied after the unintended stop of the internal combustion engine 11 (step S102: YES), the operation of the starter motor 32 is started (step S103). At this time, both the fuel injection operation by the fuel injection valve 27 and the ignition operation by the spark plug 28 are forcibly stopped.
[0104]
On the other hand, after appropriately selecting whether the starter motor 32 is operated or not, the electronic control unit 37 determines whether the condition for continuing the “ON” state of the main relay 30 is satisfied regardless of the selection. A determination is made (step S104). Specifically, it is determined whether each of the following conditions is satisfied.
The operation continuation time of the starter motor 32 is less than the predetermined time α.
The elapsed time after the internal combustion engine 11 is stopped is less than the predetermined time β.
[0105]
If it is determined that both of these conditions are satisfied (step S104: YES), the “on” state of the main relay 30 is continued (step S105), and then the present process is temporarily terminated.
[0106]
Then, thereafter, this process is repeatedly executed, and when it is determined that any one of the above conditions is not satisfied (step S104: NO), the "off" operation of the main relay 30 is permitted (step S106). ). That is, interruption of energization to the internal combustion engine 11 and its peripheral devices is permitted. Thereafter, this processing is temporarily ended.
[0107]
Hereinafter, how the operation process of the starter motor 32 is performed will be described with reference to a timing chart shown in FIG.
FIG. 7 shows an example of a processing mode of the above-described operation processing when the relative rotation phase of the intake camshaft 21 is a phase that is more retarded than the above-described startup phase when the internal combustion engine 11 is stopped.
[0108]
FIG. 7 shows each of the following items in an example of such an operation process. That is, in the figure, (a) shows the transition of the operation state of the IG switch 29, (b) shows the transition of the execution state of the injection operation by the fuel injection valve 27, and (c) shows the ignition operation of the ignition plug 28. Of the execution status of each of them. (D) shows the transition of the operation state of the main relay, (e) shows the transition of the operation state of the execution flag, and (f) shows the transition of the operation state of the shift position of the automatic transmission. I have. Further, (g) shows the transition of the operation state of the starter motor 32, (h) shows the transition of the running speed of the vehicle, (i) shows the transition of the engine rotation speed, and (j) shows the transition of the intake camshaft 21. Respectively show changes in relative rotational phase.
[0109]
In the example shown in the drawing, at time t1, the following conditions are satisfied.
-The IG switch 29 shown in FIG.
-The shift position of the automatic transmission shown in FIG.
-The relative rotational phase of the intake camshaft 21 shown in FIG. 3 (j) is a phase that is more retarded than the starting phase.
[0110]
Also, at this time t1, the execution flag is set to "OFF" as shown in FIG. 11E, and the main relay 30 is turned "ON" as shown in FIG. I have.
[0111]
By the way, at such time t1, it is assumed that an excessive load is applied to the internal combustion engine 11 and its operation is stopped. Thereafter, the internal combustion engine 11 continues to rotate due to inertia, but the engine rotation speed rapidly decreases as shown in FIG. At this time, the relative rotation phase of the intake camshaft 21 is gradually displaced so as to approach the above-described starting phase due to the reaction force accompanying the rotation of the intake camshaft 21 (FIG. 10 (j)).
[0112]
At the subsequent time t3, when the vehicle and the internal combustion engine 11 are stopped, the rotation of the intake camshaft 21 is also stopped, so that the displacement of the relative rotation phase is stopped.
[0113]
Further, at this time, if the relative rotational phase of the intake camshaft 21 when the engine is stopped is located on the retard side with respect to the start phase, the condition shown in step S100 is established. Incidentally, in the present embodiment, as described above, the detected value immediately before the engine rotation speed decreases to a speed lower than the speed N1 at which the appropriate detection of the relative rotation phase cannot be continued is determined when the engine of the intake camshaft 21 is stopped. The relative rotation phase is used. Therefore, the presence or absence of such a condition is determined based on the detected value of the relative rotation phase immediately before the time t2 when the engine rotation speed decreases to the speed N1.
[0114]
Note that, in this example, the time t2 is reached before the relative rotation phase of the intake camshaft 21 reaches the starting phase, as shown in FIG. Therefore, at time t3 when the unintended stop of the internal combustion engine 11 is confirmed, the condition of the step S100 is satisfied, and the execution flag is turned on (FIG. (E)).
[0115]
At time t4, when the shift position of the automatic transmission is operated to the N range as shown in FIG. 11F, the operation condition of step S102 is satisfied, and is shown in FIG. As described above, the operation of the starter motor 32 is started, and the internal combustion engine 11 is driven by the motor. As a result, the intake camshaft 21 is rotated, and a reaction force accompanying the rotation is generated. Therefore, as described above, the displacement of the relative rotation phase of the intake camshaft 21 stopped before reaching the start phase to the advance side is started again (FIG. 10 (j)).
[0116]
Incidentally, in the present embodiment, as described above, regarding the operation of the starter motor 32 at this time, the fuel injection and ignition of the internal combustion engine 11 are not executed in conjunction therewith (step S103). Therefore, at this time, the fuel injection operation and the ignition operation of the internal combustion engine 11 are forcibly held in the stopped state as shown in FIGS. 3B and 3C, and the starter motor 32 operates. There is no attempt to restart the internal combustion engine 11.
[0117]
In this example, the relative rotation phase of the intake camshaft 21 is displaced to the starting phase at time t5 by the operation of the starter motor 32 after the engine stops, and the relative rotation by the lock mechanism 76 of the variable valve timing mechanism 24 is performed. The phase is locked.
[0118]
At a subsequent time t6, if the continuation time of the operation of the starter motor 32 exceeds the predetermined time α, the main relay 30 is turned “OFF” as shown in FIG. Is turned off. Accordingly, the operation of the starter motor 32 is also stopped.
[0119]
Incidentally, in the present embodiment, as shown by a dashed line in FIG. 7A, even if the IG switch 29 is turned "OFF" before the time t6 by the driver, the main relay 30 is turned "ON". State is maintained.
[0120]
As described above, according to the present embodiment, the following effects can be obtained.
(1) In this embodiment, the starter motor 32 is driven for a predetermined time α when the relative rotation phase of the intake camshaft 21 when the internal combustion engine 11 is stopped is a phase that is more retarded than the start phase. I did it. Thus, the occurrence of a situation in which the internal combustion engine 11 starts to start while the relative rotation phase of the intake camshaft 21 remains largely shifted to the retard side from the start phase is effectively suppressed. As a result, favorable maintenance of good engine startability can be achieved.
[0121]
(2) In the present embodiment, the operation of the starter motor 32 is executed only when the internal combustion engine 11 is stopped unintentionally. As a result, the starter motor 32 is operated only when the internal combustion engine 11 is likely to be stopped with the intake valve 19 having an inappropriate valve timing for starting the engine. Therefore, it is possible to preferably suppress the crankshaft 14 from being forcibly rotated at unnecessary timing.
[0122]
(3) In the present embodiment, the operation of the starter motor 32 is executed on condition that the shift position of the automatic transmission is operated to the N range. As a result, the operation of the starter motor 32 is executed on condition that the power transmission system from the crankshaft 14 to the wheels is in a non-transmission state. As a result, the crankshaft 14 can be appropriately driven.
[0123]
(4) In the present embodiment, the main relay 30 is turned off when the elapsed time after the stop of the internal combustion engine 11 reaches the predetermined time β. Accordingly, it is possible to prevent the "on" state of the main relay 30 from being unnecessarily maintained for a long time after the engine is stopped by not shifting the shift position of the automatic transmission to the N range. Therefore, it is possible to preferably suppress waste of power.
[0124]
(5) In the present embodiment, the “relative rotation phase of the intake camshaft 21 when the internal combustion engine 11 is stopped” is the same relative rotation phase calculated when the engine rotation speed is equal to or higher than the predetermined rotation speed N1. The phase calculated last is used. Thereby, as the “relative rotation phase of the intake camshaft 21 when the internal combustion engine 11 is stopped”, the phase detected last among the well-detected relative rotation phases of the intake camshaft 21, that is, when the engine is stopped most Can be used.
[0125]
(6) In the present embodiment, when the starter motor 32 is operated, both the injection operation by the fuel injection valve 27 and the ignition operation by the spark plug 28 are forcibly stopped. This makes it possible to omit operations unnecessary for moving the relative rotational phase of the intake camshafts 21.
[0126]
The above embodiment may be implemented with the following modifications.
In the above-described embodiment, the configuration of the pushing mechanism 53 can be arbitrarily changed as long as it can be urged so that the relative rotation phase of the intake camshaft 21 becomes the starting phase.
[0127]
In the above embodiment, the configuration of the lock mechanism 76 can be arbitrarily changed. The point is that the relative rotation phase of the intake camshaft 21 can be fixed in a state where the valve timing is the start timing.
[0128]
In the above-described embodiment, the present invention is applied to the valve timing control device including the lock mechanism 76 that fixes the relative rotation phase of the intake camshaft 21 at the starting phase. The present invention is also applicable to a valve timing control device not provided.
[0129]
In the above embodiment, the “relative rotation phase of the intake camshaft 21 when the internal combustion engine 11 is stopped” is the last of the relative rotation phases calculated when the engine rotation speed is equal to or higher than the predetermined rotation speed N1. Is used, but the present invention is not limited to this. For example, if accurate calculation of the relative rotation phase of the intake camshaft 21 can be performed even when the engine rotation speed is reduced, the relative position of the intake camshaft 21 calculated when the internal combustion engine 11 is stopped. The rotation speed itself may be used. The point is that the relative rotational phase of the intake camshaft 21 when the internal combustion engine 11 stops can be accurately estimated or detected.
[0130]
In the above embodiment, the present invention is applied to the internal combustion engine 11 equipped with the automatic transmission, but the present invention is also applicable to the internal combustion engine 11 equipped with the manual transmission. Incidentally, in the above-described embodiment, an example of application to a vehicle equipped with an automatic transmission has been described, and the fact that the shift position of the automatic transmission is set to the N range indicates that the starter motor 32 after the engine is stopped. Is set as one of the execution conditions of the operation of. When the present invention is applied to a vehicle equipped with a manual transmission as described above, similar execution conditions can be set as follows. For example, if a sensor for detecting that the shift position of the manual transmission is at the N position is provided, it is possible to determine whether the same execution condition is satisfied based on the detection result of the sensor. Further, even if a sensor for detecting whether or not a clutch provided between the manual transmission and the internal combustion engine 11 is connected is provided, the same execution condition is satisfied based on the detection result of the sensor. The presence or absence can be determined. The point is that the starter after the engine stop is provided only with a sensor for detecting whether the power transmission system from the crankshaft 14 to the wheels is in a non-transmission state, and only when the non-transmission state is detected. If the operation of the motor 32 is executed, the effect described in the above (3) can be obtained.
[0131]
Further, the confirmation that the power transmission system from the crankshaft 14 to the wheels is in a non-transmission state may be omitted from the execution condition of the operation of the starter motor 32 after the engine is stopped. In short, if it is known in advance that the power transmission system from the crankshaft 14 to the wheels is in the non-transmission state when the starter motor 32 is operated after the engine is stopped, such confirmation need not be performed. .
[0132]
In the above embodiment, it is determined that the internal combustion engine 11 has been stopped unintentionally by satisfying the condition (a). However, the present invention is not limited to this. In short, as long as it can be appropriately determined that the internal combustion engine 11 has been stopped unintentionally, the conditions used for the determination can be changed as appropriate.
[0133]
In the above embodiment, the starter motor 32 is operated under the condition that the internal combustion engine 11 is stopped unintentionally. However, the present invention is not limited to this. If it is possible to suitably determine that the relative rotation phase of the intake camshaft 21 when the engine is stopped is larger than the starting phase and is shifted to the retard side, the above conditions may be appropriately changed or omitted.
[0134]
In the above-described embodiment, the starter motor 32 is operated when the relative rotation phase of the intake camshaft 21 when the engine is stopped is on the more retarded side than the start phase, but is not limited to this. . Alternatively or additionally, the starter motor 32 may be operated when the relative rotation phase of the intake camshaft 21 when the engine is stopped is a phase advanced from the start phase. According to such a configuration, the relative rotation phase can be shifted to the retard side by the torque Tk acting on the intake camshaft 21 as the intake camshaft 21 rotates. Thus, the occurrence of a situation in which the internal combustion engine 11 starts to start while the relative rotational phase of the intake camshaft 21 remains largely shifted from the starting phase to the advanced angle side can be effectively suppressed. become. Therefore, even with such a configuration, it is possible to appropriately maintain good engine startability.
[0135]
In the above-described embodiment, when the condition for operating the starter motor 32 is satisfied, the operation of the starter motor 32 is started immediately and continued for a predetermined time α thereafter, but is not limited thereto. For example, the timing at which the operation of the starter motor 32 is started may be set to a timing at which a predetermined time has elapsed after the above conditions are satisfied. In short, the starter motor 32 may be operated for a predetermined period before the temperature of the hydraulic oil excessively decreases.
[0136]
-In the said embodiment, although the starter motor 32 was used as a structure for forcibly driving the crankshaft 14, it is not limited to this. As such a configuration, for example, a dedicated motor separately provided, a traveling motor of a hybrid vehicle, or the like can be used. The point is that the crankshaft 14 and the camshaft 21 can be forcedly driven to rotate.
[0137]
In the above embodiment, the present invention is applied to the device that variably controls the relative rotation phase of the intake camshaft 21 with respect to the crankshaft 14, but the present invention is not limited to this. That is, the present invention can be applied to a device that variably controls the relative rotation phase of the exhaust camshaft 22 with respect to the crankshaft 14.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of an internal combustion engine and peripheral devices to which an embodiment of the present invention is applied;
FIG. 2 is a block diagram showing a schematic configuration of a variable valve timing mechanism and peripheral devices according to the embodiment;
FIG. 3 is a sectional view showing the internal structure of the variable valve timing mechanism.
FIG. 4 is a graph showing the relationship between each torque acting on an intake camshaft and valve timing.
FIG. 5 is a cross-sectional view showing a cross-sectional structure of the lock mechanism according to the embodiment along the line DD of FIG. 3;
FIG. 6 is a flowchart showing a processing procedure of a starter motor operation process.
FIG. 7 is a timing chart showing an example of a processing mode of the operation processing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Internal combustion engine, 11a ... Cylinder block, 11c ... Oil pan, 12 ... Piston, 13 ... Connecting rod, 14 ... Crankshaft, 15 ... Cylinder head, 15a ... Bearing part, 16 ... Combustion chamber, 17 ... Intake port, 18 ... exhaust port, 19 ... intake valve, 20 ... exhaust valve, 21 ... intake camshaft, 21a ... journal, 22 ... exhaust camshaft, 24 ... variable valve timing mechanism, 24a ... gear, 25 ... intake passage, 26 ... exhaust passage , 27 ... fuel injection valve, 28 ... spark plug, 28a ... igniter, 29 ... ignition switch, 30 ... main relay, 31 ... battery, 32 ... starter motor, 33 ... vehicle speed sensor, 34 ... shift position sensor, 35 ... crank angle Sensor, 36: cam angle sensor, 37: electronic control unit, 38: spark plug 41: rotating member, 42: bolt, 44: ring cover, 44a: inner peripheral surface, 45: closing plate, 46: bolt, 47: advance-side oil passage, 48: retard-side oil passage, 49: oil control valve , 50 ... supply passage, 51 ... discharge passage, 52 ... oil pump, 53 ... extrusion mechanism, 54 ... coil spring, 55 ... push pin, 62 ... coil spring, 63 ... spool, 64 ... valve part, 65 ... electromagnetic solenoid, 66, overhang, 67, groove, 68a, 68b, 68c, 68d, vane, 69, advance pressure chamber, 70, retard pressure chamber, 76, lock mechanism, 78, lock pin, 78a, flange, 79: hole, 80: coil spring, 81: accommodation hole, 82: oil chamber, 83: passage, 84: oil chamber, 85: passage.

Claims (10)

A camshaft which is drivingly connected to a crankshaft of an internal combustion engine for a vehicle is advanced based on the pressure of a fluid selectively supplied to the advance side pressure chamber and the retard side pressure chamber with respect to the crankshaft. A variable valve timing mechanism for the internal combustion engine that changes to one of the side and the retard side, and advances the relative rotation phase of the camshaft to a phase for starting the engine advanced by a predetermined amount from the most retarded phase. A biasing means for biasing to the corner side, and a valve timing control device for a vehicle internal combustion engine having
A valve timing control apparatus for an internal combustion engine for a vehicle, comprising: driving means for forcibly driving the camshaft, wherein the driving means forcibly drives the crankshaft for a predetermined period when the engine is stopped. The valve timing control device for a vehicle internal combustion engine according to claim 1,
A valve timing control device for an internal combustion engine for a vehicle, further comprising a lock unit that locks a relative rotation phase of the camshaft with a phase for starting the engine. 3. The valve for a vehicle internal combustion engine according to claim 1, wherein the forced rotation drive of the crankshaft is executed on condition that a relative rotation phase of the camshaft when the engine is stopped is not in the phase for starting the engine. Timing control device. 3. The vehicle according to claim 1, wherein the forced rotation drive of the crankshaft is executed only when a relative rotation phase of the camshaft when the engine is stopped is on a retard side with respect to the phase for starting the engine. 4. A valve timing control device for an internal combustion engine. The valve timing control device for a vehicle internal combustion engine according to any one of claims 1 to 4, wherein the forced rotation drive of the crankshaft is performed only when the internal combustion engine is unintentionally stopped. 6. The unintentional stop of the internal combustion engine is determined based on the fact that when the engine is stopped, the power transmission system from the crankshaft to the wheels is in a transmission state and an ignition switch is on. Valve timing control device for an internal combustion engine for a vehicle. The valve of the internal combustion engine for a vehicle according to any one of claims 1 to 6, wherein the forced rotation drive of the crankshaft is performed on condition that a power transmission system from the crankshaft to the wheel is in a non-transmission state. Timing control device. The drive means for forcibly driving the crankshaft based on power supply, and when the power transmission system is not in the non-transmission state for a predetermined time after the internal combustion engine is stopped, the drive means The valve timing control device for an internal combustion engine for a vehicle according to claim 7, wherein the power supply to the vehicle is interrupted. 9. The relative rotation phase of the camshaft when the engine is stopped is the phase detected last in the detection history of the relative rotation phase when the engine rotation speed is equal to or higher than a predetermined rotation speed. A valve timing control device for an internal combustion engine for a vehicle according to any one of the preceding claims. The valve timing control device for a vehicle internal combustion engine according to any one of claims 1 to 9, wherein when the crankshaft is forcibly driven to rotate, both a fuel injection operation to the internal combustion engine and an ignition operation to the fuel are stopped. .

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