JP2010138698A - Variable valve timing control apparatus for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the variation of a phase with a camshaft phase suddenly changed during unlocking after starting, in a variable valve timing apparatus with a lock phase set at a generally middle phase within an adjustable range of the camshaft phase. <P>SOLUTION: Oil filling control for filling oil into the advancing chamber and retarding chamber of the variable valve timing apparatus 18 is performed before shifting from a lock mode to a phase feedback control mode after starting. The control duty of a phase controlling hydraulic control valve 25 is changed so that one of advancing chamber oil filling control for filling oil into the advancing chamber and retarding chamber oil filling control for filling oil into the retarding chamber is performed and the other is subsequently performed while maintaining the control duty of the lock controlling hydraulic control valve 26 into a control duty for maintaining the locked state of a lock pin 58 during a period for performing the oil filling control. Until the oil filling control is completed, the unlocking of the lock pin 58 is prohibited to maintain the lock pin 58 into the locked state. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a variable valve timing control device for an internal combustion engine that adjusts valve timing by changing a rotational phase of a cam shaft (hereinafter referred to as “cam shaft phase”) with respect to a crankshaft of the internal combustion engine using hydraulic pressure as a drive source. .

Conventionally, in a hydraulically driven variable valve timing device, as described in Patent Document 1 (Japanese Patent Laid-Open No. 9-324613) and Patent Document 2 (Japanese Patent Laid-Open No. 2001-159330), the engine is stopped. The lock phase is set approximately in the middle of the adjustable range of the cam shaft phase, so that the adjustable range of the valve timing (cam shaft phase) is expanded. In this system, the intermediate lock phase that is locked when the engine is stopped is set to a phase suitable for starting, and the engine is started with this intermediate lock phase. After the start is completed, the lock is released and the camshaft phase is set according to the engine operating state. The target phase is controlled.
JP-A-9-324613 JP 2001-159330 A

  By the way, the variable valve timing device is in a state where oil in the advance chamber (advance side hydraulic chamber) and retard chamber (retard side hydraulic chamber) is released while the engine is stopped, and the hydraulic pressure in each hydraulic chamber is lowered. If the unlocking is performed immediately after the unlocking request is generated after the engine is started, there is a possibility that each hydraulic chamber is not yet sufficiently filled with oil (hydraulic pressure) at that time. If unlocking is performed when each hydraulic chamber is not sufficiently filled with oil (the hydraulic pressure in each hydraulic chamber is insufficient), the camshaft phase can be maintained at the moment the lock is released. As a result, a phase fluctuation occurs in which the camshaft phase changes suddenly toward the hydraulic chamber having a lower hydraulic pressure, which causes problems such as deterioration in combustibility and unstable engine rotation.

  The present invention has been made in consideration of such circumstances. Therefore, the object of the present invention is to provide a camshaft when the internal combustion engine is started with the camshaft phase locked at the intermediate lock phase when the lock is released after the start. An object of the present invention is to provide a variable valve timing control device for an internal combustion engine that can prevent a phase fluctuation in which the phase suddenly changes in an unstable manner.

  In order to achieve the above object, an invention according to claim 1 is a variable valve timing device that adjusts a valve timing by changing a rotational phase of a cam shaft (hereinafter referred to as “cam shaft phase”) with respect to a crankshaft of an internal combustion engine. A lock pin that locks the camshaft phase with an intermediate lock phase positioned substantially in the middle of the adjustable range when the internal combustion engine is stopped, and a hydraulic control that controls the hydraulic pressure that drives the variable valve timing device and the lock pin A variable valve timing control device for an internal combustion engine that switches between a lock mode in which the cam shaft phase is locked at the intermediate lock phase by the lock pin and a phase feedback control mode in which the cam shaft phase is controlled to a target phase. The phase feedback control mode from the lock mode after the internal combustion engine is started. And an oil filling control means for performing oil filling control for filling the advance angle chamber and the retard angle chamber of the variable valve timing device before the operation of the internal combustion engine by the oil filling control means. Until the filling control is completed, unlocking of the lock pin is prohibited and the lock pin is maintained in the locked state.

  In this configuration, unlocking is prohibited until the oil filling control for filling the oil chambers (advancing chamber and retarding chamber) with oil is completed after the internal combustion engine is started. Even if a lock release request is generated when the chamber is not filled with oil, it is possible to prevent the lock from being released, and it is possible to prevent a phase fluctuation in which the camshaft phase changes unstably and suddenly when the lock is released.

  In this case, the oil filling control may be performed until the oil pressure sensor or the like detects that the oil chamber has been filled after the start-up. However, providing the oil pressure sensor or the like increases the cost. The demand for cost reduction, which is an important technical issue, cannot be met.

  Therefore, as in claim 2, oil filling control may be executed until a predetermined time elapses from the start of the internal combustion engine (start of cranking). Since the time required to fill each hydraulic chamber with oil can be measured in advance using design data, test data, etc., the execution time of oil filling control is determined in advance based on design data, test data, etc. If the configuration for controlling the execution time of the oil filling control is achieved, there is an advantage that the configuration can be simplified and the cost reduction can be satisfied.

  In addition, the hydraulic control device has a configuration that individually includes a phase control hydraulic control valve that controls the hydraulic pressure that drives the variable valve timing device, and a lock control hydraulic control valve that controls the hydraulic pressure that drives the lock pin. A hydraulic control valve function for phase control that controls the hydraulic pressure that drives the variable valve timing device and a hydraulic control valve function for lock control that controls the hydraulic pressure that drives the lock pin are integrated. A hydraulic control valve may be used.

  When using a hydraulic control device having a separate hydraulic control valve for phase control and a hydraulic control valve for lock control, control the phase while controlling the hydraulic control valve for lock control in the lock direction. In consideration of the fact that the hydraulic control valve can be controlled in either the advance angle direction or the retard angle direction, the oil pressure for lock control can be controlled during the execution of the oil filling control. While maintaining the control amount of the control valve at a control amount that maintains the lock state of the lock pin, the advance chamber oil filling control for filling the advance chamber oil and the retard chamber oil filling control for filling the retard chamber oil are performed. It is preferable to switch the control amount of the hydraulic control valve for phase control so that either one is performed and the other is performed. In this way, it is possible to reliably fill both the advance chamber and the retard chamber while maintaining the locked state during the execution period of the oil filling control.

  Further, as in claim 4, when it is detected that the camshaft phase has changed during the oil filling control and the lock pin is unlocked, the oil filling control is stopped. The hydraulic control device may be controlled so that the cam shaft phase is controlled to the most retarded angle phase or the most advanced angle phase. If the lock pin is unlocked when the advance chamber and retard chamber are not filled with oil, the camshaft phase becomes unstable and the camshaft phase becomes unstable (fluctuates significantly). If it is determined that the lock pin is unlocked during the execution, the oil filling control is stopped immediately, and if only one of the advance chamber and the retard chamber is filled with oil, the camshaft phase Can be quickly pressed against the limit phase (the most retarded angle phase or the most advanced angle phase) of the adjustable range, so that the camshaft phase can be prevented from violating rapidly.

  Further, as in claim 5, when it is determined that the lock pin is unlocked during the oil filling control, the target idle speed after the start of the internal combustion engine is set to the target idle speed in the locked state. It is better to set higher. In this way, when it is determined that the lock pin is unlocked during the oil filling control, if the target idle rotation speed after starting is increased, the rotation speed of the oil pump (oil discharge flow rate) ) Can be increased to fill the hydraulic chamber with oil earlier, and fluctuations in the actual camshaft phase can be suppressed to suppress combustion deterioration and rotation fluctuations of the internal combustion engine.

  In this case, as described in claim 6, when it is found that the lock pin is unlocked during the oil filling control, the oil filling control is stopped and the time required for the oil filling control is shorter. It is preferable that the camshaft phase is controlled to the most retarded angle phase or the most advanced angle phase until the predetermined time elapses and then the normal control (lock control or phase feedback control) is performed.

  The time required to change the camshaft phase to the most retarded phase or the most advanced angle phase by filling only one of the advanced angle chamber and the retarded angle chamber with oil is the time required for both the advanced angle chamber and the retarded angle chamber. Since it is shorter than the time required to fill the oil, when it is found that the lock pin is unlocked during the oil filling control, the camshaft phase is temporarily set to the most retarded angle phase or the most advanced angle phase. If the control is shifted to normal control and then the normal control is performed, even if the lock pin is unlocked during the oil filling control, the camshaft phase is prevented from becoming unstable and the normal control is performed relatively early. Control can be transferred.

  Further, as in claim 7, the hydraulic control valve function for phase control for controlling the hydraulic pressure for driving the variable valve timing device and the hydraulic control valve function for lock control for controlling the hydraulic pressure for driving the lock pin are integrated. In the case of using the hydraulic control valve, after filling the oil into the chamber that can be filled with oil while maintaining the lock state of the lock pin among the advance chamber and the retard chamber after the internal combustion engine is started, When the first unlock request is generated, the control amount of the hydraulic control valve may be switched so that the other chamber is filled with oil until a predetermined time elapses or until the camshaft phase starts to move. In this way, even when using a hydraulic control valve that integrates a hydraulic control valve function for phase control and a hydraulic control valve function for lock control, the camshaft phase changes suddenly and unstablely when the lock is released after startup. It is possible to prevent phase fluctuations.

  In this case, as described in claim 8, when it is determined that the lock pin is unlocked during the oil filling control, the other of the advance chamber and the retard chamber is filled with oil. Then, it is preferable to shift to normal control (lock control or phase feedback control). In this way, even when the lock pin is unlocked during the execution of the oil filling control, it is possible to shift to the normal control relatively early while preventing the camshaft phase from being disturbed.

  Hereinafter, two embodiments 1 and 2 which are embodied by applying the best mode for carrying out the present invention to a variable valve timing control device for an intake valve will be described.

A first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, in an engine 11 that is an internal combustion engine, power from a crankshaft 12 is transmitted to an intake side camshaft 16 and an exhaust side camshaft 17 via sprockets 14 and 15 by a timing chain 13. It is like that. However, the intake side camshaft 16 is provided with a variable valve timing device 18 that adjusts the advance amount (camshaft phase) of the intake side camshaft 16 with respect to the crankshaft 12.

  A cam angle sensor 19 that outputs a cam angle signal pulse at a specific cam angle for cylinder discrimination is installed on the outer peripheral side of the intake side cam shaft 16, while a predetermined angle is provided on the outer peripheral side of the crank shaft 12. A crank angle sensor 20 that outputs a crank angle signal pulse for each crank angle is provided. The output signals of the cam angle sensor 19 and the crank angle sensor 20 are input to an engine control circuit 21, which calculates the actual valve timing (actual cam shaft phase) of the intake valve and the crank angle sensor. The engine speed is calculated based on the frequency of 20 output pulses (pulse interval). Further, output signals from various sensors (intake pressure sensor 22, water temperature sensor 23, throttle sensor 24, etc.) for detecting the engine operating state are input to the engine control circuit 21.

  The engine control circuit 21 performs fuel injection control and ignition control according to the engine operating state detected by the various sensors, performs variable valve timing control (phase feedback control), and performs actual valve timing (intake side) of the intake valve. The hydraulic pressure for driving the variable valve timing device 18 is feedback-controlled so that the actual cam shaft phase of the cam shaft 16 matches the target valve timing (target phase).

Next, the configuration of the variable valve timing device 18 will be described with reference to FIGS.
A housing 31 of the variable valve timing device 18 is fastened and fixed with bolts 32 to a sprocket 14 that is rotatably supported on the outer periphery of the intake camshaft 16. Thereby, the rotation of the crankshaft 12 is transmitted to the sprocket 14 and the housing 31 via the timing chain 13, and the sprocket 14 and the housing 31 rotate in synchronization with the crankshaft 12.

On the other hand, a rotor 35 is fastened and fixed to one end of the intake side camshaft 16 with a bolt 37. The rotor 35 is housed in the housing 31 so as to be relatively rotatable.
As shown in FIG. 3, a plurality of oil filling chambers 40 are formed inside the housing 31, and each oil filling chamber 40 is advanced by an advance chamber 42 (advance angle) by a vane 41 formed on the outer peripheral portion of the rotor 35. And a retarding chamber 43 (retarding hydraulic chamber). Stoppers 56 that restrict the relative rotation range of the rotor 35 (vane 41) with respect to the housing 31 are formed on both side portions of the at least one vane 41. The stopper 56 allows the camshaft phase to be adjusted in the latest range. The angular phase and the most advanced angle phase are regulated.

  The variable valve timing device 18 is provided with an intermediate lock mechanism 50 that locks the cam shaft phase with an intermediate lock phase located approximately in the middle of the adjustable range. The configuration of the intermediate lock mechanism 50 will be described. Any one or a plurality of vanes 41 is provided with a lock pin accommodation hole 57, and the lock pin accommodation hole 57 has a relative relationship between the housing 31 and the rotor 35 (vane 41). A lock pin 58 for locking the rotation is accommodated so as to protrude, and the lock pin 58 protrudes toward the sprocket 14 and fits into the lock hole 59 of the sprocket 14, so that the cam shaft phase is substantially within the adjustable range. Locked with an intermediate lock phase located in the middle. This intermediate lock phase is set to a phase suitable for starting the engine 11. The lock hole 59 may be provided in the housing 31.

  The lock pin 58 is urged in the lock direction (projection direction) by the spring 62. Further, between the outer peripheral portion of the lock pin 58 and the lock pin accommodation hole 57, an unlocking hydraulic chamber for controlling the hydraulic pressure for driving the lock pin 58 in the unlocking direction is formed. The housing 31 is provided with a torsion coil spring 55 (see FIG. 2) that assists the hydraulic pressure that relatively rotates the rotor 35 in the advance angle direction with the spring force during the advance angle control.

  In the first embodiment, the hydraulic control device that controls the hydraulic pressure that drives the variable valve timing device 18 and the lock pin 58 includes the phase control hydraulic control valve 25 that controls the hydraulic pressure that drives the variable valve timing device 18, The lock control hydraulic control valve 26 for controlling the hydraulic pressure for driving the pin 58 is individually provided. The hydraulic pressure control valve 25 for phase control is constituted by, for example, a 5-port, 3-position type spool valve, and the hydraulic pressure control valve 26 for lock control is constituted by, for example, a 3-port, 2-position type spool valve.

  The oil in the oil pan 27 is pumped up by an oil pump 28 driven by the power of the engine 11 and supplied to the hydraulic control valves 25 and 26, and the variable valve timing device 18 is advanced by the hydraulic control valve 25 for phase control. The hydraulic pressure (oil amount) supplied to the corner chamber 42 and the retard chamber 43 is controlled, and the hydraulic pressure (oil amount) for driving the lock pin 58 in the unlocking direction is controlled by the hydraulic control valve 26 for lock control. A check valve 29 for preventing backflow of oil is provided on the inlet port side of the hydraulic control valve 25 for phase control.

  The engine control circuit 21 calculates a target phase (target valve timing) based on engine operating conditions during phase feedback control (variable valve timing control), and calculates the actual cam shaft phase of the intake side camshaft 16 (the actual value of the intake valve). The control duty (control amount) of the hydraulic control valve 25 for phase control is feedback controlled so that the valve timing) matches the target phase (target valve timing), and the advance chamber 42 and the retard chamber of the variable valve timing device 18 are controlled. The hydraulic pressure supplied to 43 is feedback controlled.

  When a lock request is generated during this phase feedback control, lock control is executed to lock the actual camshaft phase with the intermediate lock phase by fitting the lock pin 58 into the lock hole 59 of the sprocket 14 as follows. . First, the lock control hydraulic control valve 26 is switched to the drain port, the hydraulic pressure in the lock release hydraulic chamber in the lock pin accommodation hole 57 is released, and the lock pin 58 is biased by the spring 62 in the lock direction (protrusion direction). However, variable phase control is performed to control the hydraulic control valve 25 for phase control so that the actual cam shaft phase passes the intermediate lock phase, and the actual cam shaft phase moves near the intermediate lock phase during this phase variable control. When the actual cam shaft phase still does not move when the control duty of the hydraulic control valve 25 for phase control is further changed by a predetermined amount in the direction in which the actual cam shaft phase is moved. Is fitted in the lock hole 59 and the actual camshaft phase is locked at the intermediate lock phase).

  Further, in the first embodiment, in order to perform the lock control of the lock pin 58 and the determination of the lock completion more reliably, when the actual camshaft phase stops moving near the intermediate lock phase during the phase variable control, The control duty of the hydraulic control valve 25 is changed alternately by a predetermined amount in the advance direction and the retard direction, and when the actual cam shaft phase does not move in either direction, it is determined that the lock is completed. .

  When the engine 11 is started, the engine 11 is cranked with a starter (not shown) while the actual camshaft phase is locked at the intermediate lock phase by the lock pin 58, and the phase is started from the lock mode after the start. Before shifting to the feedback control mode, the oil filling control for filling the advance chamber 42 and the retard chamber 43 of the variable valve timing device 18 with oil is executed, and the lock pin 58 is kept until the oil filling control is completed after the start. The lock pin 58 is kept in the locked state by prohibiting the unlocking of the lock.

  In this case, the oil filling control may be executed until the hydraulic chambers 42 and 43 are filled with oil after the start-up until the oil pressure sensor or the like is detected. However, it cannot meet the demand for cost reduction, which is an important technical problem in recent years.

  Therefore, in the first embodiment, the oil filling control is executed until a predetermined time has elapsed from the start of the engine (start of cranking). Since the time required to fill the hydraulic chambers 42 and 43 with oil can be measured in advance using design data, test data, or the like, the execution time of oil filling control is determined in advance based on design data, test data, or the like. If the execution time of the oil filling control is controlled by the timer, there is an advantage that the configuration can be simplified and the cost reduction can be satisfied.

  In the first embodiment, the hydraulic control valve 25 for phase control that controls the hydraulic pressure that drives the variable valve timing device 18 and the hydraulic control valve 26 for lock control that controls the hydraulic pressure that drives the lock pin 58 are individually provided. Therefore, it is possible to control the hydraulic control valve 25 for phase control in either the advance angle direction or the retard angle direction while controlling the hydraulic control valve 26 for lock control in the lock direction. .

  In consideration of this point, in the first embodiment, the control duty of the hydraulic control valve 26 for lock control is kept at the control duty for maintaining the lock state of the lock pin 58 during the oil filling control execution period. Hydraulic control valve for phase control so that one of the advance chamber oil filling control for filling the corner chamber 42 with oil and the retard chamber oil filling control for filling the retard chamber 43 with oil is performed after the other. The control duty of 25 is switched. In this way, during the execution period of oil filling control (advancing chamber oil filling control and retarding chamber oil filling control), oil is supplied to both the advance chamber 42 and the retard chamber 43 while maintaining the locked state. Can be reliably filled.

  In addition, when it is detected that the actual cam shaft phase has changed during the oil filling control, and it is determined that the lock pin 58 is unlocked, the oil filling control is stopped and the actual cam shaft phase is changed. The control duty of the hydraulic control valve 25 for phase control is switched so as to control to the most retarded angle phase (or most advanced angle phase). If the lock pin 58 is unlocked in a state where the advance chamber 42 and the retard chamber 43 are not filled with oil, the actual cam shaft phase becomes unstable and the actual cam shaft phase becomes unstable (fluctuates greatly). In the middle of the execution of the oil filling control, when it is found that the lock pin 58 is unlocked, the oil filling control is immediately stopped, and the oil is supplied to only one of the advance chamber 42 and the retard chamber 43. , The actual camshaft phase can be quickly pressed against the most retarded angle phase (or the most advanced angle phase) within the adjustable range, and the actual camshaft phase can be prevented from being violated quickly.

  Further, in the first embodiment, when it is determined that the lock pin 58 is unlocked during the execution of the oil filling control, the oil filling control is stopped, and the target idle rotational speed of the fast idle after the start is set. The actual camshaft phase is set to the most retarded angle phase or the most advanced angle until a predetermined time set shorter than the time required for the oil filling control has elapsed while being set higher than the target idle rotation speed of the fast idle in the locked state. After controlling to the phase, the control is shifted to normal control (lock control or phase feedback control).

  As described above, when it is determined that the lock pin 58 is unlocked during the oil filling control, if the target idle speed of the fast idle after the start is increased, the rotation of the oil pump 28 that pumps up the oil By increasing the speed (oil discharge flow rate), the advance chamber 42 or the retard chamber 43 can be filled with oil more quickly, and the fluctuation of the actual cam shaft phase can be suppressed to suppress the deterioration of combustion and the rotation fluctuation of the engine 11. Can do.

  Moreover, the time required to fill only one of the advance chamber 42 and the retard chamber 43 with oil and change the camshaft phase to the most retarded phase or the most advanced angle phase is the same as that of the advance chamber 42 and the retarded chamber 43. Since it is shorter than the time required to fill both the corner chambers 43 with oil, when it is determined that the lock pin 58 is unlocked during the oil filling control, the camshaft phase is temporarily set to the latest phase. If the control is shifted to the normal phase after controlling to the angular phase or the most advanced angle phase, even if the lock pin 58 is unlocked during the oil filling control, the camshaft phase is prevented from being ramped. However, it is possible to shift to normal control relatively early.

A control example of the variable valve timing device 18 at the start of the first embodiment described above will be described with reference to FIGS.
FIG. 4 is a control example when the engine 11 is started by cranking with a starter in a state where the actual camshaft phase is locked at the intermediate lock phase by the lock pin 58. In the example of FIG. 4, at the time t1, cranking is started, and at the same time, the control duty of the hydraulic control valve 25 for phase control is an advance side duty for filling the advance chamber 42 with oil. The advance chamber oil filling control for filling the advance chamber 42 with oil is performed by setting the control duty (0%). Thereafter, at the time t2 when the start of the engine 11 is completed, the cranking is finished and the routine shifts to the normal fast idle control, and the engine rotational speed is controlled to the normal fast idle target idle rotational speed.

  Then, at the time t3 when the advance chamber oil filling control is executed for a predetermined time B, the control duty of the hydraulic control valve 25 for phase control is, for example, the retard side duty for filling the retard chamber 43 with oil. The control shifts to the angular phase control duty (100%) and shifts to retarded chamber oil filling control for filling the retarded chamber 43 with oil. From the start of cranking to the completion of the advance chamber oil filling control and the retard chamber oil filling control, unlocking of the lock pin 58 is prohibited and the lock pin 58 is maintained in the locked state.

  Then, at the time t4 when the retarded chamber oil filling control is executed for a predetermined time C, the routine shifts to normal control (lock continuation control or phase feedback control). When performing the lock continuation control, the control duty of the hydraulic control valve 25 for phase control is set to a predetermined amount retarded side from the holding duty for keeping the actual camshaft phase constant in order to prevent the actual camshaft phase from being disturbed. The control duty is shifted to the advanced angle side), and the back of the lock pin 58 in the lock hole 59 is packed on the retarded side (or advanced side), and the lock pin 58 is weakened to the inner periphery of the lock hole 59. Hold in the pressed state.

  Further, when a lock release request is generated during the lock continuation control (lock mode), the lock control hydraulic pressure control valve 26 is switched from the drain port to the hydraulic pressure supply port to release the lock release hydraulic chamber in the lock pin accommodation hole 57. Then, the lock pin 58 is driven in the unlocking direction to release the lock. At this time, the transition to the phase feedback control mode is delayed until a predetermined period elapses after the lock release request is generated, and the actual camshaft phase is brought close to the intermediate lock phase while driving the lock pin 58 in the lock release direction. The control duty of the hydraulic control valve 25 for phase control is controlled so as to control, and the phase feedback control mode is entered after the predetermined period.

  In short, the transition to the phase feedback control mode is prohibited and the actual camshaft phase is in the vicinity of the intermediate lock phase (delayed by a predetermined amount or advanced side from the holding duty) until a predetermined period elapses after the unlock request is generated. If the lock release control is performed while the control pin is being controlled to a control duty shifted to), the lock pin 58 is locked by driving the actual camshaft phase by phase feedback control while the lock pin 58 is being extracted from the lock hole 57. It is possible to shift to the phase feedback control mode after the unlocking is completed by preventing the occurrence of a problem that the lock pin 58 is strongly pressed against the inner peripheral edge of the hole 57 and cannot be removed from the lock hole 57. When an unlock request is issued, the actual camshaft phase is driven to the target phase after the lock is reliably released (phase Readback control) can be initiated.

  On the other hand, FIG. 5 shows a control example when the engine 11 is started by cranking with a starter in a state where the lock pin 58 is unlocked. In this case as well, the control duty of the hydraulic control valve 25 for phase control is set to the control duty (0%) of the most advanced angle phase at the start of cranking t1, and the advance chamber oil filling control is started. During the execution of the filling control (advance chamber oil filling control and retarding chamber oil filling control), it is determined that the lock pin 58 is unlocked at the time t2 when it is detected that the camshaft phase has changed. , Stop the advance chamber oil filling control. Then, the target idle rotation speed of the fast idle after the start is set higher than the target idle rotation speed of the fast idle in the locked state, and the oil filling control (advancing chamber oil filling control and retarding chamber oil filling control) Until the predetermined time set shorter than the time required for the phase control has elapsed, the control duty of the hydraulic control valve 25 for phase control is switched to the control duty (100%) of the most retarded phase, and the most retarded angle control is executed. Press the actual cam shaft phase against the most retarded phase. The control duty of the hydraulic control valve 25 for phase control is switched to the control duty (0%) of the most advanced angle phase to execute the most advanced angle control so that the actual camshaft phase is pressed against the most advanced angle phase. May be.

  Then, after the start of the most retarded angle control (or the most advanced angle control), the most retarded angle control (or most advanced angle control) is performed at a time t3 when a predetermined time set shorter than the time required for the oil filling control has elapsed. After the completion, after a predetermined time has elapsed and the hydraulic pressure has increased, the control shifts to normal control (lock control or phase feedback control).

  In the examples of FIGS. 4 and 5, the advance chamber oil filling control is performed after cranking is started and then switched to the retard chamber oil filling control. Conversely, the retard chamber oil filling control is performed. May be switched to advance chamber oil filling control.

  The variable valve timing control at the start of the first embodiment described above is executed by the engine control circuit 21 according to the start-up variable valve timing control routine of FIG.

  The starting variable valve timing control routine of FIG. 6 is repeatedly executed at a predetermined cycle during the power-on period of the engine control circuit 21 (while the ignition switch is on), and serves as an oil filling control means in the claims. Fulfill. When this routine is started, first, at step 101, it is determined whether or not it is during cranking or within a predetermined time A after starting. If the predetermined time A has elapsed before cranking or after starting, Since it is not necessary to perform variable valve timing control, this routine is terminated without performing the subsequent processing.

  On the other hand, if it is determined in the above step 101 that the cranking is in progress or within the predetermined time A after the start, the process proceeds to step 102 and whether or not the actual camshaft phase has changed (stable near the intermediate lock phase). Whether or not). As a result, if it is determined that the actual camshaft phase has not fluctuated (stable near the intermediate lock phase), it is determined that the lock pin 58 is in the locked state, and the routine proceeds to step 104 where cranking starts. It is determined whether or not the execution time of the advance chamber oil filling control (the control duty of the hydraulic control valve 25 for phase control = 0%) has reached a predetermined time B, and the advance chamber oil filling control is still in progress. If the execution time has not reached the predetermined time B, the routine proceeds to step 105, the control duty of the hydraulic control valve 25 for phase control is maintained at 0%, and the advance chamber oil filling control is continued to advance the advance chamber 42. Fill with oil.

  Thereafter, when the execution time of the advance chamber oil filling control reaches the predetermined time B, the routine proceeds from step 104 to step 106, where the retard chamber oil filling control (control duty of the hydraulic control valve 25 for phase control = 100%). ) Is determined whether or not the execution time of the retarded chamber oil filling control has reached the predetermined time C. If the execution time of the retard chamber oil filling control has not yet reached the predetermined time C, the process proceeds to step 107 to The retarding chamber oil filling control is continued while maintaining the control duty of the hydraulic control valve 25 at 100%, and the retarding chamber 43 is filled with oil.

  If it is determined in step 102 that the actual camshaft phase has changed during execution of oil filling control (advancing chamber oil filling control and retarding chamber oil filling control), the lock pin 58 is unlocked. In step 103, the oil filling control (advancing chamber oil filling control and retarding chamber oil filling control) is stopped, and the control duty of the hydraulic control valve 25 for phase control is set to 100% (or 0). %) To execute the most retarded angle control (or most advanced angle control) and press the actual cam shaft phase against the most retarded angle phase (or most advanced angle phase). This most retarded angle control (or most advanced angle control) is executed until a predetermined time set shorter than the time required for oil filling control (advancing chamber oil filling control and retarding chamber oil filling control) elapses. Then, after the hydraulic pressure rises, the control shifts to normal control (lock control or phase feedback control).

  On the other hand, when the lock pin 58 is maintained in the locked state from the start of cranking and the execution time of the retard chamber oil filling control reaches the predetermined time C, the retard chamber oil filling control is terminated. Thereafter, the routine proceeds to step 108, where it is determined whether or not a lock request has occurred. If a lock request has occurred, the routine proceeds to step 109, where the control duty of the hydraulic control valve 25 for phase control is set to the actual cam. By switching from a holding duty that keeps the shaft phase constant to a control duty shifted by a predetermined amount α retarded side (or advanced angle side), the back of the lock pin 58 in the lock hole 59 is retarded (or advanced angle). And the lock pin 58 is held in a state of being weakly pressed against the inner periphery of the lock hole 59 (lock mode).

  Thereafter, when a lock release request is generated, the process proceeds from step 108 to step 110 to execute lock release control, and the lock control hydraulic pressure control valve 26 is switched from the drain port to the hydraulic pressure supply port. After the hydraulic pressure is supplied to the unlocking hydraulic chamber 57 in 57 and the lock pin 58 is driven in the unlocking direction to release the lock, the process proceeds to step 111 to shift to phase feedback control. In this case, even if a lock release request occurs before completion of oil filling control (advancing chamber oil filling control and retarding chamber oil filling control), unlocking is prohibited until oil filling control is completed. The lock release control is executed after the control is completed.

  In the first embodiment described above, the oil filling control for filling the advance chamber 42 and the retard chamber 43 of the variable valve timing device 18 is performed before shifting from the lock mode to the phase feedback control mode after starting. At the same time, the lock pin 58 is prohibited from being unlocked and the lock pin 58 is kept locked until the oil filling control is completed after starting. Even when a lock release request is generated when oil is not filled in 43, it is possible to prevent the lock release from occurring, and to prevent a phase ramp that causes the camshaft phase to change unstably and suddenly when the lock is released. be able to.

  In the first embodiment, the hydraulic control valve 25 for phase control that controls the hydraulic pressure that drives the variable valve timing device 18 and the hydraulic control valve 26 for lock control that controls the hydraulic pressure that drives the lock pin 58 are individually provided. In the second embodiment of the present invention shown in FIGS. 7 to 11, the hydraulic control valve function for phase control for controlling the hydraulic pressure for driving the variable valve timing device 70 and the hydraulic pressure for driving the lock pin 58 are provided. A hydraulic control valve 71 integrated with a hydraulic control valve function for lock control to be controlled is used.

  Since the configuration of the variable valve timing device 70 of the second embodiment is substantially the same as that of the variable valve timing device 18 of the first embodiment, the same reference numerals as those of the first embodiment are used and description thereof is omitted. .

  On the other hand, a hydraulic control valve 71 in which a hydraulic control valve function for phase control and a hydraulic control valve function for lock control are integrated is constituted by, for example, an 8-port, 4-position type spool valve. As shown in FIG. 8, according to the control duty of the hydraulic control valve 71, the control mode is divided into four control areas: a lock mode (weak advance mode), an advance mode, a holding mode, and a retard mode.

  In the control region of the lock mode (weak advance angle mode), the lock pin control port of the hydraulic control valve 71 is communicated with the drain port, and the hydraulic pressure in the lock release hydraulic chamber in the lock pin accommodation hole 57 is released. While urging the lock pin 58 in the locking direction (protruding direction) and communicating the retard port to the drain port and releasing the hydraulic pressure of the retard chamber 43, the hydraulic pressure is controlled according to the control duty of the hydraulic control valve 71. By gradually changing the throttle of the oil passage at the advance port of the control valve 71, oil is gradually supplied from the advance port to the advance chamber 42 to drive the actual camshaft phase gradually in the advance direction.

  In the control region of the advance angle mode, the retard control port 71 of the hydraulic control valve 71 is connected to the drain port, and the hydraulic pressure of the retard chamber 43 is released, and the hydraulic control valve 71 is controlled according to the control duty of the hydraulic control valve 71. The actual camshaft phase is advanced by changing the hydraulic pressure supplied to the advance chamber 42 from the advance port.

In the control region of the holding mode, the hydraulic pressures of both the advance chamber 42 and the retard chamber 43 are held so that the actual cam shaft phase does not move.
In the control region of the retard angle mode, the hydraulic control valve 71 is communicated according to the control duty of the hydraulic control valve 71 with the advance port of the hydraulic control valve 71 connected to the drain port and the hydraulic pressure of the advance chamber 42 is released. The actual camshaft phase is retarded by changing the hydraulic pressure supplied to the retard chamber 43 from the retard port.

  In control areas other than the lock mode (retarding mode, holding mode, advance angle mode), the unlocking hydraulic chamber in the lock pin receiving hole 57 is filled with oil to increase the hydraulic pressure of the unlocking hydraulic chamber, The lock pin 58 is extracted from the lock hole 59 by hydraulic pressure, and the lock pin 58 is unlocked.

  In the second embodiment, the control mode is switched in the order of the lock mode (weak advance angle mode), advance angle mode, holding mode, and retard angle mode as the control duty of the hydraulic control valve 71 increases. However, for example, as the control duty of the hydraulic control valve 71 increases, the control mode is switched in the order of the retard angle mode, the holding mode, the advance angle mode, and the lock mode (weak advance angle mode), or Alternatively, the order of the retard angle mode and the advance angle mode may be switched so that the control mode is switched in the order of the lock mode (weak advance angle mode), the retard angle mode, the holding mode, and the advance angle mode. In addition, when the control area in the lock mode (weak advance angle mode) and the control area in the retard angle mode are continuous, in the control area in the lock mode (weak advance angle mode), the lock is released in the lock pin accommodation hole 57. The hydraulic pressure in the hydraulic chamber is released and the lock pin 58 is urged in the locking direction (protruding direction) by the spring 62, and the hydraulic pressure in the advanced chamber 42 is released by connecting the advance port to the drain port. In accordance with the control duty of the control valve 71, the oil passage throttle of the retarding port is changed little by little, and oil is gradually supplied from the retarding port to the retarding chamber 43 to gradually retard the actual camshaft phase. Drive in the direction.

  The engine control circuit 21 calculates a target phase (target valve timing) based on engine operating conditions during phase feedback control (variable valve timing control), and calculates the actual cam shaft phase of the intake side camshaft 16 (the actual value of the intake valve). Feedback control of the control duty of the hydraulic control valve 71 so that the valve timing) matches the target phase (target valve timing) and feedback control of the hydraulic pressure supplied to the advance chamber 42 and the retard chamber 43 of the variable valve timing device 70. To do.

  When a lock request is generated during this phase feedback control, the hydraulic control valve is set so that the actual camshaft phase passes the intermediate lock phase in the direction opposite to the drive direction in the lock mode (the retarded direction in this embodiment 2). After the phase variable control (lock delay angle control) for controlling 71 is executed, the mode shifts to the lock mode and the spring pin 62 urges the lock pin 58 in the lock direction while changing the actual camshaft phase to the intermediate lock phase direction ( In the second embodiment, the hydraulic control valve 71 is controlled so as to be gently driven in the advance direction).

  Furthermore, in the second embodiment, the hydraulic control valve 71 is configured to be able to adjust the phase variable torque in the advance angle direction (or the retard angle direction) in accordance with the control duty within the control region of the lock mode, and is in the lock mode. The hydraulic control valve 71 is controlled so that the phase variable torque is gradually increased when the actual camshaft phase is gently driven in the direction of the intermediate lock phase while the lock pin 58 is biased in the lock direction by the spring 62. When the actual camshaft phase stops moving near the intermediate lock phase, it is determined that the lock is complete.

  In this case, even when the hydraulic control valve 71 in which the hydraulic control valve function for phase control and the hydraulic control valve function for lock control are integrated is used for some reason (for example, conditions such as oil temperature). When the actual camshaft phase stops moving at a position slightly deviated from the intermediate lock phase, it is possible to prevent the erroneous determination that the lock is complete, and to lock the actual camshaft phase with the intermediate lock phase. It is possible to determine whether the lock is complete.

  By the way, in the control characteristics of FIG. 8, since there is no lock mode on the retard side, the retard chamber 43 cannot be filled with oil while the lock pin 58 is kept locked.

  Therefore, in the second embodiment, when the oil filling control is performed after the start-up, of the advance chamber 42 and the retard chamber 43, the hydraulic chamber that can be filled with oil while maintaining the locked state of the lock pin 58 (see FIG. In the control characteristic No. 8, after the advance chamber oil filling control for filling the advance chamber 42) with oil is executed, when the first unlock request after the start is generated, until the actual camshaft phase starts to move or for a predetermined time Until the time elapses, the control duty of the hydraulic control valve 71 is switched so as to execute retarded chamber oil filling control for filling the other hydraulic chamber (retarded chamber 43 in the control characteristic of FIG. 8) with oil. .

  In this case, if it is detected that the actual camshaft phase has changed during execution of the advance chamber oil filling control and it is found that the lock pin 58 is unlocked, the advance chamber 42 and the retard angle are retarded. Of the chambers 43, the other hydraulic chamber (the retarding chamber 43 in the control characteristic of FIG. 8) is filled with oil, and then the control is shifted to normal control (lock control or phase feedback control). In this way, even when the lock pin 58 is unlocked during the execution of the oil filling control, it is possible to shift to the normal control relatively early while preventing the actual camshaft phase from being disturbed.

  The oil filling control according to the second embodiment described above is executed by the engine control circuit 21 in accordance with the routines shown in FIGS. The processing contents of these routines will be described below.

[After-starting oil filling control routine]
9 is repeatedly executed at a predetermined cycle during the power-on period of the engine control circuit 21, and serves as oil filling control means in the claims. When this routine is started, first, at step 201, it is determined whether or not it is during cranking or within a predetermined time D after starting. If it is before cranking or after the predetermined time D has elapsed after starting, oil filling is performed. Since it is not necessary to perform control, this routine is terminated without performing the subsequent processing.

  On the other hand, if it is determined in step 201 that the cranking is in progress or within a predetermined time D after starting, the process proceeds to step 202 to determine whether the lock pin 58 is unlocked or not. Judgment is made based on whether or not. As a result, if it is determined that the lock pin 58 is unlocked, the routine proceeds to step 203, where an unlocking oil filling control routine of FIG.

  On the other hand, if it is determined in step 202 that the lock pin 58 is not unlocked (the actual camshaft phase is stable near the intermediate lock phase), the process proceeds to step 204 where the control duty of the hydraulic control valve 71 is controlled. Is set to a control duty E (see FIG. 8) in which the advance angle torque becomes maximum (the oil filling flow rate to the advance angle chamber 42 is maximum) in the control region of the lock mode in which the lock pin 58 can be maintained in the locked state. . Accordingly, the advance chamber oil filling control for filling the advance chamber 42, which is the hydraulic chamber that can be filled with oil while maintaining the locked state of the lock pin 58 among the advance chamber 42 and the retard chamber 43, is performed. Execute.

  Thereafter, the routine proceeds to step 205, where it is determined whether or not the actual cam shaft phase is stable near the intermediate lock phase. If it is determined that the actual cam shaft phase is not stable near the intermediate lock phase, step 206 is performed. Then, it is determined that the lock pin 58 is unlocked, the process proceeds to step 203, and an unlocking oil filling control routine of FIG.

  On the other hand, if it is determined in step 205 that the actual camshaft phase is stable near the intermediate lock phase, the process proceeds to step 207, where the execution time of the lock mode (oil-filling control after start-up) is a predetermined time. It is determined whether or not F has been exceeded. If the execution time of the lock mode has not exceeded the predetermined time F, this routine is terminated as it is.

  Thereafter, when the execution time of the lock mode exceeds the predetermined time F, it is determined that the oil filling into the advance chamber 42 is completed, and the routine proceeds to step 208 where the control duty of the hydraulic control valve 71 is set to the lock pin. 58, the control duty (0%) for stopping the oil filling into the advance chamber 42 is set in the control mode of the lock mode in which the 58 can be maintained in the locked state, and the advance chamber oil filling control is completed. In step 209, the advance chamber oil filling control completion flag is set to "ON" which means completion of the advance chamber oil filling control.

[Oil filling control routine at unlock request]
10 is repeatedly executed at a predetermined cycle during the power-on period of the engine control circuit 21, and serves as oil filling control means in the claims. When this routine is started, first, at step 301, it is determined whether or not the advance chamber oil filling control completion flag is ON (advance chamber oil filling control completion), and the advance chamber oil filling control completion flag is determined. Is OFF (before completion of the advance chamber oil filling control), the subsequent processing is terminated without performing the subsequent processing. Thereby, even if a lock release request is generated before the advance chamber oil filling control is completed, the lock release is prohibited.

  On the other hand, if it is determined in step 301 that the advance chamber oil refill control completion flag is ON (advance chamber oil refill control completion), the process proceeds to step 302 and the first unlock request after the start is made. If the first unlock request after the start has not occurred, this routine is terminated without performing the subsequent processing.

  Thereafter, when the first unlock request after the start occurs, the process proceeds to step 303, and the control duty of the hydraulic control valve 71 is set to fill the retard chamber 43, which is the hydraulic chamber not filled with oil. The retarding chamber oil filling control for filling the retarding chamber 43 with oil is performed with the control duty (100%) at which the flow rate is maximized.

  Thereafter, the process proceeds to step 304 where the retard chamber oil filling time counter is counted up to measure the retard chamber oil filling time (the duration of the control duty of 0%). In the next step 305, the actual camshaft phase is calculated. It is determined whether or not the movement has started. As a result, if it is determined that the actual camshaft phase has not yet started to move, the process proceeds to step 307, and whether or not the count value of the retarded chamber oil filling time counter has exceeded a predetermined value (the retarded chamber oil filling time is predetermined). Whether or not the time has been exceeded) is determined, and if the count value of the retarded chamber oil filling time counter is equal to or smaller than a predetermined value, the present routine is immediately terminated. As a result, after the advance angle chamber oil filling control is executed, the delay angle chamber oil filling control is executed until the actual camshaft phase starts to move or a predetermined time elapses when the first unlock request after starting is generated. Is done.

  If the retard chamber oil filling time exceeds the predetermined time without the actual camshaft phase starting to move, the retard chamber oil filling control is terminated at that point, and the process proceeds to step 308 to execute the lock release control. Then, the lock pin 58 is unlocked. When this lock release control is performed, the target phase of the actual cam shaft phase is set near the intermediate lock phase so that the lock pin 58 is not strongly pressed against the inner periphery of the lock hole 59 (the lock pin 58 is locked). It is preferable to perform the lock release control in the control region of the holding mode by reducing the frictional force when extracting from the hole 59). After executing the lock release control, the process proceeds to step 309, where phase feedback control is executed, and the control duty of the hydraulic control valve 71 is feedback controlled so that the actual camshaft phase matches the target phase. The hydraulic pressure supplied to the corner chamber 42 and the retard chamber 43 is feedback-controlled.

  On the other hand, if the actual camshaft phase starts to move before the retarded chamber oil filling time reaches the predetermined time, it is determined that the lock has already been released at that time, and the routine proceeds to step 306 to execute phase feedback control. To do.

[Oil filling control routine when unlocked]
The unlocked oil filling control routine of FIG. 11 is the determination processing in steps 201 and 202 of the after-starting oil filling control routine of FIG. 9, and the lock pin 58 is unlocked during cranking or within a predetermined time D after starting. This is a subroutine executed in step 203 when it is found out.

  When this routine is started, first, in step 401, the control duty of the hydraulic control valve 71 is set to a control duty (100%) at which the oil filling flow rate into the retard chamber 43 is maximized, and the retard chamber 43 is set. The retard chamber oil filling control is performed to fill the oil into the tank. Thereafter, the process proceeds to step 402, where it is determined whether the engine is idling. If the engine is idling, the process proceeds to step 403, where the target idle speed is increased to increase the engine speed. As a result, the rotational speed of the oil pump 28 that pumps up the oil is increased to increase the oil oil filling flow rate into the retarding chamber 43, and the hydraulic pressure in the retarding chamber 43 is increased more quickly.

If it is determined in step 402 that the vehicle is not idling, the target idle rotation speed raising process in step 403 is not performed.
Thereafter, the routine proceeds to step 404, where it is determined whether or not the retarding chamber oil filling time (the duration of the control duty of 100%) exceeds the predetermined time G, and the retarding chamber oil filling time still exceeds the predetermined time G. If not, this routine is terminated.

  Thereafter, when the retarding chamber oil filling time exceeds the predetermined time G, it is determined that the oil filling into the retarding chamber 43 has been completed, and the routine proceeds to step 405 where normal control (lock control or phase feedback control) is performed. ).

  In the second embodiment described above, the hydraulic control valve function for phase control for controlling the hydraulic pressure for driving the variable valve timing device 70 and the hydraulic control valve function for lock control for controlling the hydraulic pressure for driving the lock pin 58 are provided. In the variable valve timing system using the integrated hydraulic control valve 71, when oil filling control is performed after starting, the oil is supplied while maintaining the locked state of the lock pin 58 in the advance chamber 42 and the retard chamber 43. After the advance chamber oil filling control for filling the hydraulic chamber (the advance angle chamber 42 in the control characteristic of FIG. 8) with which the oil can be filled is executed, the actual camshaft is Until the phase starts to move or until a predetermined time elapses, oil is controlled so as to execute retarded chamber oil filling control for filling the other hydraulic chamber (retarded chamber 43 in the control characteristics of FIG. 8) with oil. Since the control duty of the control valve 71 is switched, even when the hydraulic control valve 71 in which the hydraulic control valve function for phase control and the hydraulic control valve function for lock control are integrated is used, It is possible to prevent a phase fluctuation in which the actual camshaft phase changes abruptly.

  Moreover, in the second embodiment, when it is detected that the actual cam shaft phase has changed during the execution of the oil filling control to the advance chamber 42, and it is determined that the lock pin 58 is unlocked, Since the delay chamber 43 is filled with oil and then the normal control (lock control or phase feedback control) is performed, the lock pin 58 is locked during the oil filling control to the advance chamber 42. Even if the deviation is, the normal control can be shifted to a relatively early stage while preventing the actual camshaft phase from being disturbed.

The present invention is not limited to an intake valve variable valve timing control device, and may be applied to an exhaust valve variable valve timing control device.
In addition, the present invention can be implemented with various modifications within a range not departing from the gist, such as the configuration of the variable valve timing devices 18 and 70 and the configuration of the hydraulic control valves 25, 26, and 71 may be appropriately changed. .

It is a schematic block diagram of the whole control system which shows Example 1 of this invention. It is a vertical side view explaining the structure of the variable valve timing apparatus of Example 1, and a hydraulic control circuit. It is a vertical front view of the variable valve timing device of the first embodiment. It is a time chart which shows the example of control at the time of starting in the state which locked the real cam shaft phase of Example 1 with the intermediate | middle lock phase. It is a time chart which shows the example of control at the time of starting in the state which the lock | rock pin of Example 1 unlocked. 4 is a flowchart showing a flow of processing of a start-up variable valve timing control routine according to the first embodiment. It is a vertical side view explaining the structure of the variable valve timing apparatus of Example 2, and a hydraulic control circuit. (A) is a figure explaining the switching pattern of the advance port, retard port, and lock pin control port of the hydraulic control valve of Embodiment 2, and (b) is the lock mode, advance mode, holding mode, and retard mode. It is a control characteristic figure of a hydraulic control valve explaining the relation between these four control fields and phase change speed. 7 is a flowchart illustrating a processing flow of a post-startup oil filling control routine according to a second embodiment. 12 is a flowchart illustrating a processing flow of an oil filling control routine at the time of unlock request according to the second embodiment. 6 is a flowchart illustrating a processing flow of an unlocking oil filling control routine according to a second embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Engine (internal combustion engine), 12 ... Crankshaft, 13 ... Timing chain, 14, 15 ... Sprocket, 16 ... Intake camshaft, 17 ... Exhaust camshaft, 18 ... Variable valve timing device, 19 ... Cam angle sensor, 20 ... crank angle sensor, 21 ... engine control circuit (oil filling control means), 25 ... hydraulic control valve for phase control (hydraulic control device), 26 ... hydraulic control valve for lock control (hydraulic control device), 28 ... oil Pump, 31 ... Housing, 35 ... Rotor, 40 ... Fluid chamber, 41 ... Vane, 42 ... Advance chamber, 43 ... Delay chamber, 50 ... Intermediate lock mechanism, 58 ... Lock pin, 59 ... Lock hole, 62 ... Spring , 70 ... Variable valve timing device, 71 ... Hydraulic control valve (hydraulic control device)

Claims (8)

A variable valve timing device that adjusts the valve timing by changing the rotational phase of the camshaft relative to the crankshaft of the internal combustion engine (hereinafter referred to as “camshaft phase”), and the camshaft phase can be adjusted when the internal combustion engine is stopped. A lock pin that locks at an intermediate lock phase located approximately in the middle of the range, and a hydraulic control device that controls the hydraulic pressure that drives the variable valve timing device and the lock pin, and the cam shaft phase is adjusted to the intermediate by the lock pin. In a variable valve timing control device for an internal combustion engine that switches between a lock mode for locking with a lock phase and a phase feedback control mode for controlling the camshaft phase to a target phase,
An oil filling control means for performing oil filling control for filling oil into the advance chamber and the retard chamber of the variable valve timing device before shifting from the lock mode to the phase feedback control mode after starting the internal combustion engine;
The variable valve timing of the internal combustion engine, wherein the oil filling control means prohibits the unlocking of the lock pin and maintains the lock pin in a locked state until the oil filling control is completed after the internal combustion engine is started. Control device.   2. The variable valve timing control device for an internal combustion engine according to claim 1, wherein the oil filling control means executes the oil filling control until a predetermined time elapses from the start of the internal combustion engine. The hydraulic control device individually includes a hydraulic control valve for phase control that controls the hydraulic pressure that drives the variable valve timing device, and a hydraulic control valve for lock control that controls the hydraulic pressure that drives the lock pin. ,
The oil filling control means is configured to keep oil in the advance chamber while maintaining a control amount of the lock control hydraulic control valve at a control amount for maintaining a lock state of the lock pin during an execution period of the oil filling control. The control amount of the hydraulic control valve for phase control is set so that one of the advance chamber oil filling control for filling the retard chamber and the retard chamber oil filling control for filling the retard chamber oil is performed and then the other is performed. The variable valve timing control device for an internal combustion engine according to claim 1 or 2, wherein switching is performed.   The oil filling control unit stops the oil filling control when it is detected that the camshaft phase has changed during the oil filling control and the lock pin is unlocked. 4. The variable valve for an internal combustion engine according to claim 1, wherein the control amount of the hydraulic control device is switched so that the camshaft phase is controlled to the most retarded angle phase or the most advanced angle phase. Timing control device.   When the oil filling control means determines that the lock pin is unlocked during the oil filling control, the oil filling control means sets the target idle rotational speed after starting the internal combustion engine to the target idle rotational speed in the locked state. 5. The variable valve timing control device for an internal combustion engine according to claim 4, further comprising means for setting a higher value.   The oil filling control means stops the oil filling control when it is determined that the lock pin is unlocked during the oil filling control, and is shorter than the time required for the oil filling control. 6. The variable internal combustion engine according to claim 4, wherein the camshaft phase is controlled to the most retarded angle phase or the most advanced angle phase until a predetermined time elapses, and then the control is shifted to normal control. Valve timing control device. The hydraulic control device integrates a hydraulic control valve function for phase control that controls the hydraulic pressure that drives the variable valve timing device and a hydraulic control valve function for lock control that controls the hydraulic pressure that drives the lock pin. Using a hydraulic control valve,
The oil filling control means fills the chamber that can be filled with oil while maintaining the locked state of the lock pin among the advance chamber and the retard chamber after starting the internal combustion engine, and then after starting When the first unlock request is generated, the control amount of the hydraulic control valve is switched so that the other chamber is filled with oil until a predetermined time elapses or until the camshaft phase starts to move. The variable valve timing control device for an internal combustion engine according to claim 1.   The oil filling control means supplies oil to the other chamber of the advance chamber and the retard chamber when it is determined that the lock pin is unlocked during the execution of the oil fill control. 8. The variable valve timing control device for an internal combustion engine according to claim 7, wherein the control is shifted to normal control after filling.

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