JP2009270487A - Valve timing control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve timing control device that can remove foreign substances within a hydraulic control valve, while suppressing an influence exerted upon a control of a valve timing adjustment device. <P>SOLUTION: A valve timing adjustment device includes a housing (drive side rotating body) that rotates along with a rotation of a crankshaft (drive shaft) of an engine (internal combustion engine), a rotor (driven side rotating body) for transmitting a driving force of the crankshaft via the housing to an intake side cam stem (driven shaft) for opening and closing an intake valve, a hydraulic mechanism for relatively rotating the housing and the rotor, a hydraulic pump for supplying hydraulic fluid to the hydraulic mechanism, and an OCV (hydraulic control valve) for adjusting hydraulic fluid to be supplied from the hydraulic pump to the hydraulic mechanism. For valve timing adjustment device, it is determined whether or not supply state of hydraulic fluid to be supplied to the hydraulic mechanism is a low pressure state. If it is determined that supply state of the hydraulic fluid is the low pressure state, a control is performed so as to operate the OCV in an attempt to remove foreign substances within the OCV. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a valve timing control device that controls a valve timing adjustment device that adjusts the opening / closing timing of at least one of an intake valve and an exhaust valve.

  2. Description of the Related Art A valve timing adjusting device that adjusts opening / closing timing (valve timing) of an intake valve and an exhaust valve is known. This valve timing adjusting device is a driven side rotating body provided on a driving side rotating body driven by a crankshaft (driving shaft) of an internal combustion engine and a camshaft (driven shaft) driven by the crankshaft to open and close the valve. Body, a hydraulic mechanism that relatively rotates these two rotating bodies, a hydraulic pump that is driven by an internal combustion engine to supply hydraulic oil to the hydraulic mechanism, and a hydraulic control that adjusts the hydraulic oil supplied from the hydraulic pump to the hydraulic mechanism And a valve. The phase of the relative rotation of both rotating bodies is adjusted by opening / closing control of the hydraulic control valve, and the valve timing is adjusted accordingly.

  In this valve timing adjusting device, the camshaft receives torque from the valve spring in a direction that prevents rotation during valve opening operation, and receives torque in a direction that promotes rotation during valve closing operation. Then, the torque (fluctuation torque) received by the camshaft is transmitted to the driven rotating body. Here, when the internal combustion engine is started, the hydraulic pressure of the hydraulic oil supplied to the hydraulic mechanism is still low. For this reason, there is a problem in that both rotating bodies are in a state of swinging relatively (fluctuation state) due to the fluctuating torque, and a hitting sound is generated when the both rotating bodies collide with each other.

  As a countermeasure against this problem, a lock mechanism is provided that locks the drive-side rotator and the driven-side rotator so that they cannot rotate relative to each other at a rotation position (lock position) at which a predetermined phase difference occurs. ), It is known to perform lock control for operating a hydraulic control valve so as to relatively rotate both rotating bodies to the lock position. In this case, the next time when the internal combustion engine is started by turning on the ignition switch, both the rotating bodies are locked by the lock mechanism, so that even if the fluctuating torque is received, there is no fluttering state.

On the other hand, foreign matter contained in the hydraulic oil may be caught in the sliding portion of the hydraulic control valve. If this happens, the hydraulic control valve cannot be controlled as intended, and the valve timing cannot be adjusted accurately. As a countermeasure for this problem, in a valve timing adjusting device in which the operation amount of the hydraulic control valve is feedback controlled based on the valve timing, it is determined whether or not the operation amount of the hydraulic control valve is included in the normal range. It is known that a hydraulic control valve is forcibly opened and closed according to a determination result (see Patent Document 1). As a result, the foreign matter is detected in the sliding portion of the hydraulic control valve and the foreign matter is to be removed.
JP 2003-222034 A

  However, this cleaning process may cause inconvenience in the control of the valve timing adjusting device.

  For example, if the cleaning process is performed after the IG-off operation and before the driving side rotating body and the driven side rotating body are locked, there is a concern that both rotating bodies are not locked (lock failure). That is, after the IG-off operation, the hydraulic pressure of the hydraulic oil supplied to the hydraulic mechanism decreases as the internal combustion engine and the hydraulic pump are stopped. For this reason, when the cleaning process is performed after the IG-off operation, the hydraulic pressure is considerably lowered after the cleaning control is completed. As a result, even if the lock control is performed after the cleaning control, there may be a situation in which sufficient hydraulic pressure does not remain at that time and the two rotating bodies do not rotate relative to the lock position. In this case, a lock failure occurs.

  In addition, when the cleaning process is performed during the operation of the internal combustion engine, there is a concern that the valve timing may change (valve timing adjustment failure) as a result of opening and closing of the hydraulic control valve by the cleaning process.

  The present invention has been made to solve the above-described problems, and provides a valve timing control device capable of removing foreign matters in a hydraulic control valve while suppressing the influence on the control of the valve timing adjustment device. The main purpose is to do.

  Hereinafter, means for solving the above-described problems and the effects thereof will be described.

  The present invention is applied to an internal combustion engine equipped with a valve timing adjustment device that adjusts an opening / closing timing (valve timing) of at least one of an intake valve and an exhaust valve, and is driven by a drive side rotating body driven by a drive shaft of the internal combustion engine; A driven-side rotating body provided on a driven shaft that is driven by a driving shaft to open and close the valve, a hydraulic mechanism that relatively rotates both rotating bodies, a hydraulic pump that supplies hydraulic oil to the hydraulic mechanism, and a hydraulic pump A valve timing control device for controlling a valve timing adjustment device, comprising a hydraulic control valve for adjusting hydraulic fluid supplied to a hydraulic mechanism.

  In particular, in the first aspect of the invention, it is determined whether or not the supply state of the hydraulic oil supplied to the hydraulic mechanism is a predetermined low pressure state, and it is determined that the supply state of the hydraulic oil is a low pressure state. If this happens, the hydraulic control valve is actuated to remove foreign matter in the hydraulic control valve.

  Here, the hydraulic mechanism operates upon receiving supply of hydraulic oil. In this case, the higher the hydraulic oil pressure at the time when the hydraulic control valve for removing foreign matter is operated, the greater the influence of the operation on the operation of the hydraulic mechanism, and the influence of the operation on the control of the valve timing adjusting device. Becomes larger. In this regard, according to the first aspect of the present invention, when the supply state of the hydraulic oil supplied to the hydraulic mechanism is a predetermined low pressure state, the hydraulic control valve for removing foreign matter is operated. Thereby, the foreign matter in the hydraulic control valve can be removed while suppressing the influence on the control of the valve timing adjusting device.

  The low-pressure state of the hydraulic oil includes a state where the hydraulic pressure of the hydraulic oil supplied to the hydraulic mechanism is equivalent to atmospheric pressure.

  According to the second aspect of the present invention, the valve timing adjusting device is provided when the rotational phase of both rotating bodies is at a predetermined locking position and the hydraulic pressure supplied to the hydraulic mechanism is equal to or lower than a predetermined locking pressure. The present invention is applied to a valve timing adjusting device having a lock mechanism that locks the relative rotation of both rotating bodies. The low pressure state of the hydraulic oil is a state where the hydraulic pressure of the hydraulic oil supplied to the hydraulic mechanism is equal to or lower than the lock pressure.

  According to the second aspect of the present invention, when the hydraulic pressure supplied to the hydraulic mechanism is equal to or lower than the lock pressure, the hydraulic control valve for removing foreign matter is operated. Therefore, after the IG-off operation, the foreign matter removing hydraulic control valve is not actuated before both rotating bodies are locked by the locking mechanism. Thereby, it is possible to suppress the occurrence of a lock failure due to the operation of the hydraulic control valve for removing foreign matter.

  According to a third aspect of the present invention, the hydraulic pump is driven by an internal combustion engine, and based on at least one of the elapsed time from the stop of the internal combustion engine and the temperature of the internal combustion engine, It is determined whether the supply state is the low pressure state.

  When the hydraulic pump is driven by the internal combustion engine, when the internal combustion engine is stopped, the hydraulic pump is also stopped. Therefore, after the internal combustion engine is stopped, the hydraulic pressure of the hydraulic oil supplied to the hydraulic mechanism decreases. In addition, after the internal combustion engine stops, the temperature of the internal combustion engine also decreases. Thus, the elapsed time since the internal combustion engine stopped and the temperature of the internal combustion engine correlate with the hydraulic pressure of the hydraulic oil supplied to the hydraulic mechanism.

  Focusing on this point, it is possible to determine whether or not the supply state of the hydraulic oil is a low pressure state based on the elapsed time since the internal combustion engine stopped as described above and the temperature of the internal combustion engine. . In this case, it is determined whether or not the supply state of the hydraulic oil is a low-pressure state using existing components such as a timer that measures an elapsed time since the ignition switch is turned off and a water temperature sensor that detects the cooling water temperature of the internal combustion engine. Therefore, a sensor for detecting the hydraulic pressure of the hydraulic oil supplied to the hydraulic mechanism is not required. Thereby, the cost reduction of a valve timing control apparatus can be aimed at.

  When the hydraulic pump is driven by an electric motor, it is possible to determine whether or not the supply state of the hydraulic oil is a low pressure state based on the power supplied to the electric motor, the rotation speed of the electric motor, or the like. It is.

  According to the fourth aspect of the present invention, when it is determined that the supply state of the hydraulic oil is in a low pressure state and the ignition switch is turned on, the operation of the hydraulic control valve for removing foreign matter is started.

  According to the fourth aspect of the present invention, the operation of the hydraulic control valve for removing foreign matter is performed immediately before starting the internal combustion engine. As a result, the internal combustion engine can be started after the foreign matter in the hydraulic control valve is reliably removed. That is, foreign matter may be accumulated in the hydraulic control valve during the period from the stop of the internal combustion engine to the start of the internal combustion engine, but the hydraulic control valve for removing foreign matter is operated immediately before the start of the internal combustion engine. Thus, the internal combustion engine can be started after reliably removing the foreign matter accumulated in the hydraulic control valve as described above.

  By the way, when the hydraulic control valve is operated to remove foreign matter in the hydraulic control valve, a sound (operation sound) is generated along with the operation. Therefore, when the internal combustion engine is mounted on a vehicle, it is conceivable that the operation sound of the hydraulic control valve gives the vehicle driver a sense of discomfort.

  On the other hand, when the invention according to claim 4 is applied to an in-vehicle internal combustion engine, the uncomfortable feeling given to the driver by the operation sound of the hydraulic control valve can be reduced. That is, in many vehicles, the operation sound of the hydraulic control valve is less audible inside the vehicle than outside the vehicle. It is also considered that the driver turns on the ignition switch in the vehicle. Therefore, when the ignition switch is turned on as described above, by starting the operation of the hydraulic control valve, it is possible to operate the hydraulic control valve for removing foreign matters in a state where the driver is highly likely to be in the vehicle. As a result, the uncomfortable feeling given to the driver of the vehicle by the operation sound of the hydraulic control valve can be reduced.

  In the invention according to claim 5, the hydraulic pump is driven by an internal combustion engine, and when the supply state of the hydraulic oil is determined to be a low pressure state and the ignition switch is turned off, foreign matter removal is performed. Start the operation of the hydraulic control valve.

  According to the fifth aspect of the present invention, after the ignition switch is turned on, the ignition control is turned off again without turning on the starter switch, thereby removing the foreign matter in the hydraulic control valve. It is possible to actuate the valve.

  That is, when the hydraulic pump uses the internal combustion engine as a power source, the hydraulic pump is also stopped when the internal combustion engine is stopped, and hydraulic fluid is not supplied to the hydraulic mechanism by the hydraulic pump. Therefore, when the internal combustion engine is stopped, the supply state of hydraulic oil supplied to the hydraulic mechanism is considered to be the low pressure state. Therefore, when the ignition switch is turned off in the operation of the above-described ignition switch, the operation of the hydraulic control valve for removing foreign matter is started. Thus, by allowing the operation of forcibly executing the operation of the hydraulic control valve for removing foreign matter to be accepted, foreign matter in the hydraulic control valve can be reliably removed.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.

  As shown in FIG. 1, a gasoline engine 11 is applied to an internal combustion engine mounted on a vehicle and serving as a travel drive source, and the engine 11 is a double overhead cam type. The power from the crankshaft 12 (drive shaft) is transmitted to the intake side camshaft 16 (driven shaft) and the exhaust side camshaft 17 via the sprockets 14 and 15 by the timing chain 13. . However, the intake side camshaft 16 is provided with a valve timing adjusting device 18 that adjusts the advance amount of the intake side camshaft 16 with respect to the crankshaft 12. A cam angle sensor 19 for detecting the cam angle is installed on the outer peripheral side of the intake side cam shaft 16, while a crank angle sensor 20 for detecting the crank angle is installed on the outer peripheral side of the crank shaft 12. Yes.

  Output signals from the crank angle sensor 20 and the cam angle sensor 19 are input to the ECU 21. The ECU 21 calculates the actual valve timing of an intake valve (not shown) and calculates the engine speed from the frequency of the output pulse of the crank angle sensor 20.

  The ECU 21 is connected to various sensors (intake pressure sensor 22, water temperature sensor 23, throttle sensor 24, etc.) for detecting the engine operating state, and switches (ignition SW 25 and starter SW 26). The ECU 21 performs fuel injection control and ignition control based on these various input signals, and also performs variable valve timing control, which will be described later, to target the actual valve timing of the intake valve (actual advance angle of the intake camshaft 16). The valve timing of the valve timing adjusting device 18 is feedback controlled so as to coincide with the valve timing (target advance amount).

  Oil in the oil pan 27 is supplied to the hydraulic circuit of the valve timing adjusting device 18 as hydraulic oil by a hydraulic pump 28. The hydraulic pump 28 uses the engine 11 as a drive source, and power from the crankshaft 12 is transmitted by a timing chain.

  Then, by switching the hydraulic oil supply destination by the hydraulic pump 28 using a hydraulic control valve (OCV) 29, it is controlled whether the valve timing is changed to the advance side or the retard side. Further, the actual advance angle amount (actual valve timing) of the intake camshaft 16 is controlled by controlling the amount of hydraulic oil supplied by the OCV 29.

  The positive terminal side of the battery 73 is connected to the power supply terminal of the ECU 21 via the switch 72 of the main relay 71. When an ON signal is input from the ignition SW 25, the ECU 21 energizes the relay drive coil 74 of the main relay 71 to turn on the switch 72 of the main relay 71 and receives power supply from the battery 73. The power supplied through the main relay 71 is supplied to the entire control system such as the OCV 29 in addition to the ECU 21. The main relay 71 is continuously kept on for a predetermined time after the ignition SW 25 is turned off, and the lock control described later can be executed during that period.

  Next, the configuration of the hydraulic mechanism of the valve timing adjusting device 18 will be described with reference to FIGS.

  A housing 31 (drive-side rotator) of the valve timing adjusting device 18 is fastened and fixed with bolts 32 to a sprocket 14 that is rotatably supported on the outer periphery of the intake-side camshaft 16. Thereby, the rotation of the crankshaft 12 is transmitted to the sprocket 14 and the housing 31 through the timing chain 13, and the sprocket 14 and the housing 31 rotate in synchronization with the crankshaft 12.

  On the other hand, the intake side camshaft 16 is rotatably supported by a cylinder head 33 and a bearing cap 34, and a rotor 35 (driven side rotating body) is attached to one end of the intake side camshaft 16 via a stopper 36 and a bolt 37. It is fixed with tightening. The rotor 35 is accommodated in the housing 31 so as to be relatively rotatable.

  As shown in FIGS. 3 and 4, a plurality of hydraulic chambers 40 are formed inside the housing 31, and each hydraulic chamber 40 is delayed from the advance chamber 42 by a vane 41 formed on the outer peripheral portion of the rotor 35. It is partitioned into a corner chamber 43. Seal members 44 are attached to the outer periphery of the rotor 35 and the outer periphery of the vane 41, and each seal member 44 is urged in the outer peripheral direction by a leaf spring 45 (see FIG. 2). Thus, the gap between the outer peripheral surface of the rotor 35 and the inner peripheral surface of the housing 31 and the gap between the outer peripheral surface of the vane 41 and the inner peripheral surface of the hydraulic chamber 40 are sealed by the seal member 44.

  As shown in FIG. 2, an annular advance groove 46 and a retard groove 47 formed on the outer peripheral portion of the intake camshaft 16 are respectively connected to predetermined ports of the OCV 29, and the hydraulic pump 28 is driven by the power of the engine 11. By being driven, the oil (operating oil) pumped from the oil pan 27 is supplied to the advance groove 46 and the retard groove 47 via the OCV 29. The advance oil passage 48 connected to the advance groove 46 is formed so as to penetrate the inside of the intake side camshaft 16 and communicate with an arcuate advance oil passage 49 (see FIG. 3) formed in the rotor 35. The arcuate advance oil passage 49 communicates with each advance chamber 42. On the other hand, the retard oil passage 50 connected to the retard groove 47 passes through the inside of the intake camshaft 16 and communicates with an arc retard oil passage 51 (see FIG. 4) formed in the rotor 35. The arc-shaped retarded oil passage 51 communicates with each retarded angle chamber 43.

  The OCV 29 is a four-port, three-position switching valve that drives the valve element with a solenoid 53 and a spring 54. The valve element position is set to an advance angle supply position for supplying hydraulic oil to the advance chamber 42 and a retard chamber 43. Switching between a retard supply position for supplying hydraulic oil and a holding position for not supplying hydraulic oil to any of the advance chamber 42 and the retard chamber 43 is performed. When the energization of the solenoid 53 is stopped, the valve element is automatically switched to the position where the hydraulic oil is supplied to the advance chamber 42 by the spring 54, so that the hydraulic pressure acts in the direction in which the camshaft phase is advanced. The OCV 29 shown in FIGS. 1 and 2 indicates an operating state when the solenoid 53 is energized.

  In a state where a hydraulic pressure equal to or higher than a predetermined pressure is supplied to the advance chamber 42 and the retard chamber 43, the vane 41 is fixed by the hydraulic pressure of the advance chamber 42 and the retard chamber 43, and the housing 31 is rotated by the rotation of the crankshaft 12. The rotation is transmitted to the vane 41 via the hydraulic oil. As a result, the crankshaft 12 and the intake camshaft 16 rotate together in a state in which the rotor 35 is not swung (fluttered) with respect to the housing 31 by the above-described fluctuating torque.

  During engine operation, the hydraulic pressure in the advance chamber 42 and the retard chamber 43 is controlled by the OCV 29 to rotate the rotor 35 relative to the housing 31, thereby rotating the rotation phase of the intake camshaft 16 relative to the crankshaft 12 (cam The valve timing of the intake valve is made variable by controlling the shaft phase. Specifically, the OCV 29 is operated to the advance angle supply position or the retard angle supply position described above to rotate the rotor 35 relatively, and when the target relative rotation position is reached, the OCV 29 is operated to the holding position to rotate the rotor 35 relatively. Hold position.

  Here, when the intake side camshaft 16 drives the intake valve, the intake side camshaft 16 receives fluctuating torque that fluctuates positively and negatively from a valve spring that urges the intake valve in the valve closing direction. The fluctuation torque in the positive direction represents torque in a direction in which the rotor 35 is relatively rotated toward the retard side, and the fluctuation torque in the negative direction represents torque in a direction in which the rotor 35 is relatively rotated toward the advance side. The average of the fluctuation torque works in the positive direction, that is, in the retard direction. Therefore, when the rotor 35 is relatively rotated to the advance side, the hydraulic pressure to be relatively rotated in the advance direction in order to avoid deterioration of the response of the relative rotation as compared to the case of relative rotation to the retard side. Is provided with a coil spring 55 (see FIG. 2). The coil spring 55 is accommodated in the sprocket 14.

  As shown in FIGS. 3 and 4, a lock pin 58 (for locking the rotor 35 relative to the housing 31 so as not to rotate relative to the housing 31) is formed in the lock pin accommodation hole 57 formed in any one vane 41. The lock pin 58 is housed in a retractable manner, and the lock pin 58 is fitted into the lock hole 59 (lock mechanism) shown in FIG. Locked at the position (lock position).

  As shown in FIGS. 5 and 6, the lock pin 58 is slidably inserted into the cylindrical member 61 fitted to the inner periphery of the lock pin accommodation hole 57, and is locked in the locking direction (protruding direction) by the spring 62. It is energized. In addition, a gap between the cylindrical member 61 and the lock pin 58 is divided into a lock hydraulic chamber 64 and a release holding hydraulic chamber 65 for unlocking and holding by a valve portion 63 formed at the center outer peripheral portion of the lock pin 58. Yes. In order to supply hydraulic oil from the advance chamber 42 to the lock hydraulic chamber 64 and the release holding hydraulic chamber 65, the vane 41 has a lock oil passage 66 communicating with the advance chamber 42 and an oil passage for unlocking and holding. 67 is formed. The housing 31 is formed with an unlocking oil passage 68 that communicates the lock hole 59 and the retard chamber 43.

  In the locked state shown in FIG. 5, the valve portion 63 of the lock pin 58 closes the lock release holding oil passage 67 and the lock oil passage 66 communicates with the lock hydraulic chamber 64. As a result, hydraulic pressure is supplied from the advance chamber 42 to the lock hydraulic chamber 64, and the lock pin 58 is held in the lock hole 59 by the hydraulic pressure and the spring 62, and the camshaft phase is at the most retarded position. Locked.

  While the engine is stopped, the hydraulic pressure in the lock hydraulic chamber 64 (the hydraulic pressure in the advance chamber 42) decreases, but the lock pin 58 is held in the locked position by the spring 62. Therefore, the engine is started in a state where the lock pin 58 is held at the locked position (most retarded position), and when the hydraulic pressure in the lock hole 59 (hydraulic pressure in the retarded chamber 43) becomes high after the engine is started, the hydraulic pressure is increased. Thus, the lock pin 58 is unlocked (see FIG. 6). That is, after the engine is started, the hydraulic pressure (force in the unlocking direction) supplied from the retard chamber 43 through the unlocking oil passage 68 to the lock hole 59 is the hydraulic pressure of the lock hydraulic chamber 64 (hydraulic pressure of the advance chamber 42) and the spring. When the resultant force is greater than the resultant force of the spring force 62 (force in the locking direction), the lock pin 58 is pushed out of the lock hole 59 by the hydraulic pressure of the lock hole 59 and moves to the unlocked position, whereby the lock pin 58 is locked. Canceled.

  In this unlocked state, as shown in FIG. 6, the valve portion 63 of the lock pin 58 closes the lock oil passage 66, and the lock release holding oil passage 67 communicates with the release holding hydraulic chamber 65. . As a result, the hydraulic pressure is supplied from the advance chamber 42 to the release holding hydraulic chamber 65, and the hydraulic pressure in the release holding hydraulic chamber 65 (hydraulic pressure in the advance chamber 42) and the hydraulic pressure in the lock hole 59 (hydraulic pressure in the retard chamber 43) As a result, the lock pin 58 is held in the unlocked position against the spring 62. During engine operation, the hydraulic pressure of either the advance chamber 42 or the retard chamber 43 is high, so that the lock pin 58 is held at the unlocked position by the hydraulic pressure, and the rotor 35 is relatively rotatable. (State in which valve timing control is possible).

  The ECU 21 also functions as an advance / retard angle position control means for controlling the operation of the OCV 29 by controlling the operation of the solenoid 53, and the actual valve timing of the intake valve based on the output signals of the crank angle sensor 20 and the cam angle sensor 19. While calculating (actual advance angle amount of the intake side camshaft 16), the target valve timing of the intake valve (intake side cam) based on the outputs of various sensors that detect the engine operating state such as the intake pressure sensor 22, the water temperature sensor 23, etc. The target advance angle amount of the shaft 16 is calculated. Then, the OCV 29 of the valve timing adjusting device 18 is feedback-controlled so that the actual valve timing of the intake valve matches the target valve timing.

  In other words, the ECU 21 controls the hydraulic pressure in the advance chamber 42 and the retard chamber 43 to rotate the actual relative rotational position of the rotor 35 with respect to the housing 31 to the target relative rotational position, so that the actual valve of the intake valve can be obtained. The camshaft phase is changed so that the timing matches the target valve timing. Hereinafter, this control is referred to as “valve timing adjustment control”.

  Thereafter, when the engine 11 is stopped, when the engine rotation speed is decreased, the discharge pressure of the hydraulic pump 28 is decreased, so that the hydraulic pressure in the advance chamber 42 and the retard chamber 43 is decreased. As a result, the hydraulic pressure of the release holding hydraulic chamber 65 (hydraulic pressure of the advance chamber 42) and the hydraulic pressure of the lock hole 59 (hydraulic pressure of the retard chamber 43) are reduced, so that the spring force of the spring 62 overcomes these hydraulic pressures. Then, the lock pin 58 protrudes and fits into the lock hole 59 by the spring force of the spring 62. In this case, the discharge pressure of the hydraulic pump 28 when the lock pin 58 is fitted into the lock hole 59 as described above corresponds to the “lock pressure”.

  However, in order for the lock pin 58 to be fitted into the lock hole 59, it is a condition that the positions of the two coincide with each other, that is, the rotor 35 coincides with the most retarded position. In order to satisfy this condition, when detecting an off operation (IG off operation) of the ignition SW 25, the ECU 21 operates the OCV 29 so as to relatively rotate the rotor 35 toward the lock position (most retarded position). Is running. Hereinafter, the process of operating the OCV 29 in this lock control is referred to as “lock process”.

  If the rotor 35 can reach the most retarded angle position by this lock control, the engine 11 can be started next time by turning on the IG in the locked state in which the lock pin 58 is fitted in the lock hole 59.

  Here, since the hydraulic oil is not supplied to the advance chamber 42 and the retard chamber 43 when the engine is started, if the lock pin 58 is not fitted in the lock hole 59 and is in an unlocked state, The rotor 35 swings with respect to the housing 31 due to the fluctuating torque described above (a fluttering state), and the rotor 35 may collide with the housing 31 to generate abnormal noise and damage the valve timing adjusting device 18. However, if the above-described lock control is in the locked state when the engine is started, the rotor 35 is locked so as not to be relatively rotatable, so that the fluttering state can be avoided.

  By the way, in the valve timing adjusting device 18, foreign matters contained in the hydraulic oil, for example, impurities in the hydraulic oil or chips during cutting of the engine 11 may be caught in the sliding portion of the OCV 29. In this case, the operation amount of the OCV 29 cannot be accurately controlled, and consequently the valve timing cannot be accurately controlled. On the other hand, the valve timing adjusting device 18 performs the cleaning process when a predetermined cleaning condition is satisfied. That is, the ECU 21 determines whether or not the cleaning condition is satisfied, and greatly changes the operation amount of the OCV 29 when the condition is satisfied. Thereby, the foreign substance in OCV29 is removed.

  However, this cleaning process may cause inconvenience in the control of the valve timing adjusting device 18.

  For example, if the cleaning process is performed after the IG-off operation and before the lock process is executed, there is a concern that the valve timing adjusting device 18 cannot be locked (lock failure). That is, since the hydraulic pump 28 uses the engine 11 as a drive source, the hydraulic pressure supplied to the advance chamber 42 and the retard chamber 43 decreases after the IG-off operation. Therefore, if the cleaning process is performed before the lock process is executed after the IG-off operation as described above, sufficient hydraulic pressure does not remain at the time of the subsequent lock process, and the rotor 35 is locked. A situation may occur in which the relative rotation to the position is not possible. In this case, a lock failure occurs.

  Further, when the cleaning process is performed during the operation of the engine 11, there is a concern that the valve timing may change (valve timing adjustment failure) as a result of the operation of the OCV 29 by the cleaning process.

  Therefore, in this embodiment, in order to suppress the lock failure and the valve timing adjustment failure, the cleaning oil is supplied when the hydraulic oil is supplied to the OCV 29, the advance chamber 42, and the retard chamber 43 in a predetermined low pressure state. Processing is performed. Here, the low pressure state of the hydraulic oil means a state where the hydraulic pressure of the hydraulic oil supplied to the OCV 29 or the like is lower than the pressure in the operating state of the engine 11. In the present embodiment, in particular, the hydraulic oil is in a low pressure state in which the hydraulic oil pressure supplied to the OCV 29, the advance chamber 42, and the retard chamber 43 is lower than the lock pressure.

  Specifically, when the following condition (1) is satisfied and any of the following conditions (2) to (4) is satisfied, the cleaning flag is set for a predetermined cleaning time (for example, 500 μs). Then, a cleaning process is performed according to the cleaning flag. Here, the cleaning flag is a flag indicating whether or not to perform a cleaning process. In the present embodiment, it is assumed that the cleaning flag is set when the cleaning process is performed, and the cleaning flag is reset when the cleaning process is not performed.

(1) The supply state of hydraulic oil is a low pressure state.
(2) The ignition SW 25 has transitioned from the off state to the on state.
(3) The ignition SW 25 has transitioned from the on state to the off state.
(4) The engine 11 has transitioned from the operating state to the stopped state.

  The condition (1) is determined based on the elapsed time since the engine 11 stopped. That is, since the hydraulic pump 28 uses the engine 11 as a drive source, the hydraulic pressure of the hydraulic oil supplied to the OCV 29 and the like decreases after the engine 11 stops. Then, it is considered that the pressure becomes equal to or lower than the lock pressure after a certain time has elapsed since the engine 11 was stopped. Therefore, when the elapsed time after the engine 11 is stopped is longer than the predetermined determination time, it is possible to determine that the hydraulic oil supply state is the low pressure state.

  The conditions (2) and (3) are determined by detecting the state of the ignition SW 25 each time and comparing the current state of the ignition SW 25 with the previous state.

  The condition (4) is determined based on the engine stop flag. Here, the engine stop flag is a flag that is set when the rotational speed of the engine 11 becomes less than a predetermined speed and is reset when the rotational speed of the engine 11 becomes a predetermined speed or less.

  Hereinafter, the cleaning flag setting process will be described in detail with reference to FIG. FIG. 7 is a flowchart showing the flow of the cleaning flag setting program. This program is executed by the ECU 21 at a predetermined cycle (every predetermined crank angle or a predetermined time cycle).

  In step S10 shown in FIG. 7, the ECU 21 determines whether or not the condition (1) is satisfied, that is, whether or not the hydraulic oil supply state is a low pressure state, based on the count value of the timer 21a.

  If it is determined in step S10 that the hydraulic oil supply state is a low pressure state, the ECU 21 determines in steps S11 to S13 for the above conditions (2) to (4). That is, the ECU 21 determines whether or not the ignition SW 25 is turned on in step S11, determines whether or not the ignition SW 25 is turned off in step S12, and determines whether or not the engine stall flag is set in step S13. When the ECU 21 determines that any of the above conditions (2) to (4) is satisfied, the ECU 21 proceeds to the process of step S14, and any of the above conditions (2) to (4) is satisfied. If it is determined that there is not, the process proceeds to step S15.

  In step S14, the ECU 21 sets a cleaning flag. And ECU21 complete | finishes execution of this program.

  In step S15, the ECU 21 determines whether or not the cleaning flag is set. If the ECU 21 determines that the cleaning flag is set, the ECU 21 proceeds to step S16. If the ECU 21 determines that the cleaning flag is reset, the ECU 21 terminates execution of the current program.

  In step S16, the ECU 21 determines whether or not the elapsed time after setting the cleaning flag is equal to or longer than the cleaning time. If the ECU 21 determines that the elapsed time is equal to or longer than the cleaning time, the process proceeds to step S17. If it is determined that the elapsed time is less than the cleaning time, execution of the current program is terminated.

  If it is determined in step S10 that the hydraulic oil supply state is not a low pressure state, the ECU 21 proceeds to the process of step S17.

  In step S17, the ECU 21 resets the cleaning flag. And ECU21 complete | finishes execution of this program.

  Next, one aspect of the cleaning control will be described with reference to FIG.

  8, (a) is the open / closed state of the vehicle door, (b) is the state of supplying power to the ECU 21, (c) is the state of the ignition SW 25, (d) is the state of the starter SW 26, and (e) is the engine rotation. Speed, (f) indicates engine stop flag, (g) indicates hydraulic oil pressure, and (h) indicates transition of cleaning flag. FIG. 8 assumes the following. In FIG. 8G, P1 indicates the supply state of hydraulic oil when the engine 11 is operating.

  When the vehicle door is opened at the timing t1 shown in FIG. 8, power supply to the ECU 21 is started.

  When the IG-on operation is performed at a timing t2 when a fixed time has elapsed from the stop of the engine 11 and the hydraulic oil supply state is in a low pressure state, the above conditions (1) and (2) are satisfied. Thereby, the cleaning flag is set. Then, at timing t3 when the cleaning time has elapsed from timing t2, the cleaning flag is reset. As a result, the OCV 29 is cleaned at timings t2 to t3.

  When the starter SW is turned on at timing t4, the engine rotation speed increases, and the hydraulic oil pressure supplied to the OCV 29 and the like increases. Then, at the timing t5 when the engine rotation speed reaches the predetermined speed N1, the engine stop flag is reset.

  Thereafter, when an engine stall occurs at timing t6, the engine rotation speed decreases, and as a result, the hydraulic pressure of the hydraulic oil supplied to the OCV 29 or the like decreases.

  Then, at the timing t7, when the engine speed becomes equal to or lower than the predetermined speed N1, the engine stop flag is set. Thereby, the condition (4) is established. However, at this timing, it is determined that a certain period of time has not elapsed since the engine 11 is stopped, and the hydraulic oil supply state is not the low pressure state. In this case, the cleaning flag is not set. That is, although the condition (4) is satisfied, the execution of the cleaning process is prohibited by the condition (1).

  When the starter SW is turned on at timing t8, the engine speed increases again, and the hydraulic pressure of the hydraulic oil supplied to the OCV 29 and the like increases. Then, at the timing t9 when the engine rotation speed reaches the predetermined speed N1, the engine stop flag is reset again.

  When the IG-off operation is performed at timing t10, the condition (3) is satisfied. Further, when the engine rotational speed is reduced along with the IG off operation and the engine rotational speed reaches a predetermined speed N1 at timing t11, the engine stop flag is set again. Thereby, the condition (4) is also satisfied. However, at these timings t10 and t11, the condition (1) is not satisfied and the cleaning flag is not set, similarly to the timing t6. In this case, although the condition (3) or the condition (4) is satisfied, the execution of the cleaning process is prohibited by the condition (1).

  When the IG-on operation is performed at a timing t12 when the hydraulic oil supply state is in a low pressure state after a certain period of time has elapsed since the engine 11 is stopped, the conditions (1) and (2) are similar to those at the timing t2. Since it is established, the cleaning flag is set. The cleaning flag is reset at timing t13 when the cleaning time has elapsed from timing t12.

  Furthermore, when the IG-off operation is performed at timing t14 when a time equal to or longer than the cleaning time has elapsed from timing t12, the condition (3) is satisfied. Moreover, since the starter SW 26 is not turned on after the timing IG 12 when the IG is turned on, and the engine 11 is stopped, the hydraulic oil is supplied at a low pressure at the timing t14. Determined. In this case, since the conditions (1) and (3) are satisfied, the cleaning flag is set again. Then, at timing t15 when the cleaning time has elapsed from timing t14, the cleaning flag is reset again. As a result, the cleaning process is continuously executed twice at timings t12 to t15.

  When the driver of the vehicle repeatedly performs the operation at the timing t12 to t15, that is, when the IG on operation and the IG off operation are repeatedly performed without turning on the starter SW 26, the cleaning process is continuously performed. And is done multiple times.

  Further, at timing t12 to t15, it is assumed that the driver performs the IG on operation and the IG off operation with an interval equal to or longer than the cleaning time. However, the driver performs the IG on operation and the IG off operation at intervals equal to or greater than the cleaning time. When the operation is performed without leaving the time, the setting time of the cleaning flag is extended, and as a result, the execution time of the cleaning control is extended.

  According to the embodiment described in detail above, the following excellent effects can be obtained.

  The valve timing adjusting device 18 operates by receiving supply of hydraulic oil. In this case, the higher the hydraulic oil pressure at the time of execution of the cleaning process, the greater the influence of the cleaning process on the control of the valve timing adjusting device 18. On the other hand, the cleaning process is performed when the hydraulic oil pressure is equal to or lower than the lock pressure. As a result, it is possible to remove foreign matters in the OCV 29 by the cleaning control while suppressing the influence of the cleaning process on the control of the valve timing adjusting device 18.

  In particular, the hydraulic oil is in a low pressure state in which the hydraulic pressure of the hydraulic oil supplied to the OCV 29, the advance chamber 42, and the retard chamber 43 is lower than the lock pressure. As a result, the cleaning process is not executed during the period from when the engine 11 is stopped until the hydraulic pressure of the hydraulic oil becomes equal to or lower than the lock pressure. As a result, the influence of the cleaning process on the lock control can be eliminated, and the lock failure of the valve timing adjusting device 18 can be effectively suppressed. Further, the cleaning process is not executed while the engine 11 is in operation. As a result, the influence of the cleaning process on the valve timing adjustment control can be eliminated, and the valve timing adjustment failure of the valve timing adjustment device 18 can be suppressed.

  The cleaning process was started with the IG ON operation. As a result, the cleaning process is executed immediately before the engine 11 is started. Thereby, the engine 11 can be started after the foreign matter in the OCV 29 is reliably removed. That is, it is conceivable that foreign matter accumulates in the OCV 29 during the period from the stop of the engine 11 to the start of the engine 11. However, by executing the cleaning process immediately before the start of the engine 11, as described above, The engine 11 can be started after removing the foreign matter accumulated on the surface.

  By the way, when the cleaning process is executed, an operation sound is generated in the OCV 29. For this reason, it is conceivable that this operating sound gives the vehicle driver a feeling of strangeness. In this regard, as described above, the cleaning process is started in accordance with the IG-on operation, so that the uncomfortable feeling given to the driver by the operating sound of the OCV 29 can be reduced. That is, in many vehicles, the operating sound of the OCV 29 is less audible inside the vehicle than outside the vehicle. The IG-on operation is performed in the vehicle by the driver. Therefore, when the cleaning process is started along with the IG-on operation, the cleaning process can be executed with a high probability that the driver is in the vehicle and the cleaning process is performed. The uncomfortable feeling given to the driver by the operating sound of the OCV 29 can be reduced.

  Based on the elapsed time after the engine 11 is stopped, it is determined whether or not the supply state of the hydraulic oil is a low pressure state. In this case, a sensor for detecting the hydraulic oil pressure is not required. As a result, the cost of the valve timing adjusting device 18 can be reduced.

  By repeatedly performing the IG on operation and the IG off operation without turning on the starter SW 26, the cleaning process can be continuously executed or the cleaning process can be extended. Thereby, the foreign material in OCV29 can be removed reliably.

(Other embodiments)
The present invention is not limited to the description of the above embodiment, and may be implemented as follows, for example.

  -Based on the information regarding the temperature of the engine 11, you may make it determine whether the supply state of the hydraulic fluid supplied to OCV29 grade | etc. Is a low pressure state. When the engine 11 is stopped, the temperature of the engine 11 is lowered together with the hydraulic pressure of the hydraulic oil supplied to the OCV 29 and the like. Therefore, it can be determined whether or not the supply state of the hydraulic oil is a low pressure state based on the information related to the temperature of the engine 11. Even in this case, a sensor for detecting the hydraulic pressure of the hydraulic oil supplied to the OCV 29 or the like is not required as in the above embodiment, which is preferable from the viewpoint of cost reduction of the valve timing adjusting device. That is, the information regarding the temperature of the engine 11 is used for various controls other than the cleaning control, as is the elapsed time since the engine 11 stopped. Therefore, it is possible to determine whether or not the supply state of the hydraulic oil is a low-pressure state based on a detection value of an existing sensor that detects information related to the temperature of the engine 11, for example, the water temperature sensor 23.

  In addition, a pressure sensor for detecting the hydraulic pressure of the hydraulic oil supplied to the OCV 29 or the like is provided, and it is determined whether or not the hydraulic oil supply state is a low pressure state based on a detection value by the pressure sensor. Is possible. In this case, the supply state of the hydraulic oil is lower than that in the case where the hydraulic pressure is estimated from parameters other than the hydraulic pressure of the hydraulic oil (information on the elapsed time since the engine 11 stopped and the temperature of the engine 11). It is preferable in that it can be accurately determined.

  In the above embodiment, the reset condition of the cleaning flag is that the supply state of the hydraulic oil supplied to the OCV 29 or the like is not a low pressure state, and that the cleaning time has elapsed since the cleaning flag was set. However, the present invention is not limited to this. For example, the start condition of the starter SW 26 may be changed from the off state to the on state as the cleaning flag reset condition. In this case, the cleaning process can be terminated before the hydraulic pressure of the hydraulic oil supplied to the advance chamber 42 and the retard chamber 43 increases as the engine speed increases. Thereby, the influence which the cleaning process has on the control (valve timing adjustment control or the like) of the valve timing adjusting device 18 can be effectively suppressed.

  The present invention can also be applied to a valve timing adjusting device including an electric hydraulic pump that uses an electric motor as a power source. In this case, it can be determined whether or not the supply state of the hydraulic oil supplied to the OCV 29 or the like is a low pressure state based on the supply power to the motor, the rotation speed of the motor, or the like. Further, as long as the supply state of the hydraulic oil is a low pressure state, the cleaning process can be executed at a desired timing. For example, it is possible to execute the cleaning process after a predetermined time has elapsed since the door of the vehicle was closed. In this case, the cleaning process can be executed at a timing when the driver is sufficiently away from the vehicle after driving the vehicle. Thereby, the uncomfortable feeling which the operating sound of OCV29 accompanying a cleaning process gives to a driver | operator can be reduced.

  In the above embodiment, the present invention is applied to the control of the valve timing adjusting device 18 of the intake side camshaft 16. However, the present invention is not limited to this, and the present invention may be applied to control of the valve timing adjusting device when the valve timing adjusting device is provided on the exhaust side camshaft 17.

1 is a schematic configuration diagram illustrating an entire control system according to an embodiment of the present invention. The longitudinal cross-sectional view which shows a valve timing adjustment apparatus. II sectional drawing of FIG. II-II sectional drawing of FIG. Sectional drawing which shows the locked state by the locking mechanism of FIG. Sectional drawing which shows the lock release state by the locking mechanism of FIG. The flowchart which shows the flow of the cleaning flag setting program. The timing chart which shows the one aspect | mode of cleaning control.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Gasoline engine (internal combustion engine), 12 ... Crankshaft (drive shaft), 16 ... Intake side camshaft (driven shaft), 18 ... Valve timing adjusting device, 21 ... ECU (Supply state judging means, cleaning means), 28 DESCRIPTION OF SYMBOLS ... Hydraulic pump, 31 ... Housing (drive side rotating body), 35 ... Rotor (driven side rotating body), 58 ... Lock pin (lock mechanism), 59 ... Lock hole (lock mechanism).

Claims (5)

Applied to an internal combustion engine equipped with a valve timing adjustment device for adjusting the opening / closing timing of at least one of an intake valve and an exhaust valve;
The valve timing adjusting device includes: a driving side rotating body driven by a driving shaft of the internal combustion engine; a driven side rotating body provided on a driven shaft that is driven by the driving shaft to open and close the valve; A hydraulic mechanism that relatively rotates the two rotating bodies, a hydraulic pump that supplies hydraulic oil to the hydraulic mechanism, and a hydraulic control valve that adjusts the hydraulic oil supplied from the hydraulic pump to the hydraulic mechanism. Yes,
Supply state determination means for determining whether or not the supply state of hydraulic oil supplied to the hydraulic mechanism is a predetermined low pressure state;
Cleaning means for operating the hydraulic control valve to remove foreign matter in the hydraulic control valve when the supply state determining means determines that the hydraulic oil supply state is a low pressure state;
A valve timing control device comprising: The valve timing adjusting device is provided on the condition that the rotational phase of both the rotating bodies is at a predetermined locking position and the hydraulic pressure of the hydraulic oil supplied to the hydraulic mechanism is equal to or lower than a predetermined locking pressure. It has a lock mechanism that locks the relative rotation of both rotating bodies in an impossible manner,
The valve timing control device according to claim 1, wherein the low pressure state is a state in which a hydraulic pressure of hydraulic oil supplied to the hydraulic mechanism is equal to or lower than the lock pressure. The hydraulic pump is driven by the internal combustion engine,
The supply state determination means determines the supply state of the hydraulic oil based on at least one of an elapsed time since the internal combustion engine stopped and a temperature of the internal combustion engine. 3. The valve timing control device according to 1 or 2.   The cleaning unit starts the operation of the hydraulic control valve for removing foreign matter when the supply state of the hydraulic oil is determined by the supply state determination unit to be a low pressure state and the ignition switch is turned on. The valve timing control device according to any one of claims 1 to 3. The hydraulic pump is driven by the internal combustion engine,
The cleaning unit starts the operation of the hydraulic control valve for removing the foreign matter when the supply state determination unit determines that the supply state of the hydraulic oil is a low pressure state and the ignition switch is turned off. The valve timing control apparatus as described in any one of Claims 1 thru | or 4.

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