JP2007332957A - Control device for vane type variable valve timing adjustment mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the responsiveness of variable valve timing control in a vane type variable valve timing adjustment mechanism (VCT) without posing the problem of overshoot in a control area in which a response characteristic of the VCT to current (OCV current) of a hydraulic control valve is delayed. <P>SOLUTION: An OCV target current is set at a holding current to hold an actual advance quantity at about a target advance quantity during execution of holding control. Minute displacement control (pulse excitation control) is started at points of time t1, t3 and t5 where the deviation between an actual advance quantity and a target advance quantity enters a minute displacement control area over a holding control area (determination threshold KKP) during execution of the holding control, and an oil pressure control valve is pulse-excited to drive the VCT in the direction of the target advance quantity in a pulse-like manner. According to this, when the actual advance quantity is returned to about the target advance quantity, the holding control is restored, and the OCV target current is set at the holding current to hold the actual advance quantity at the target advance quantity. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention controls the hydraulic pressure of the advance chamber and the retard chamber by the hydraulic control valve so as to drive the vane type variable valve timing adjusting mechanism in the direction of the target displacement angle, thereby setting the actual displacement angle to the target displacement angle. The present invention relates to a control device for a vane type variable valve timing adjusting mechanism to be matched.

In recent years, in internal combustion engines (engines) mounted on vehicles, variable valve timing that varies the valve timing (cam shaft displacement angle) of intake valves and exhaust valves for the purpose of improving output, reducing fuel consumption, and reducing exhaust emissions. The number of machines that employ adjustment mechanisms is increasing. For example, the basic configuration of a vane type variable valve timing adjustment mechanism is, as shown in Patent Document 1 (Japanese Patent Laid-Open No. 2001-159330), a housing that rotates in synchronization with an engine crankshaft, an intake valve ( Or a vane rotor connected to a camshaft of an exhaust valve) is coaxially arranged, and a plurality of vane storage chambers formed in the housing are advanced and retarded chambers by vanes (blade portions) on the outer periphery side of the vane rotor. Divide into Then, by controlling the hydraulic pressure in each hydraulic chamber with a hydraulic control valve and rotating the vane rotor relative to the housing, the camshaft displacement angle (camshaft phase) with respect to the crankshaft is changed to change the valve timing. Variable control is performed.
JP 2001-159330 A (pages 4 to 6 etc.)

  In general, the vane type variable valve timing adjustment mechanism (hereinafter referred to as “VCT”) does not have a linear response characteristic of the VCT with respect to the hydraulic control valve current (hereinafter referred to as “OCV current”), and holds the VCT at a fixed position. There is a region where the response is slow in the vicinity of the holding current. In this region, even if the OCV current is feedback-controlled according to the deviation between the target displacement angle and the actual displacement angle, the VCT movement is slow and the VCT cannot be driven in the direction of the target displacement angle with good response.

  As a countermeasure, if the feedback gain is increased too much, an overshoot occurs and the convergence of the actual displacement angle to the target displacement angle deteriorates, causing problems such as deterioration of engine combustion.

  The present invention has been made in view of such circumstances. Therefore, the object of the present invention is to control a vane variable valve timing adjustment mechanism that can drive a VCT more responsively than before without causing an overshoot problem. To provide an apparatus.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a plurality of vane storage chambers formed in a housing of a vane type variable valve timing adjustment mechanism (VCT). A hydraulic control valve that controls the hydraulic pressure of the advance chamber and the retard chamber, and the current of the hydraulic control valve is controlled according to the deviation between the actual displacement angle and the target displacement angle of the VCT In a control device of a vane type variable valve timing adjustment mechanism having a control means for performing pulse energization control for driving the VCT in the direction of a target displacement angle by energizing the hydraulic control valve with pulses. It is.

  As in the present invention, if the hydraulic control valve is energized with a pulse, even if a relatively large pulse current is applied, the energization time is very small, so that the VCT displacement amount (advance amount / retard angle amount) is also minute. . For this reason, if the hydraulic control valve is energized with pulses, the VCT can be driven more responsively than before without causing the problem of overshoot.

  In the present invention, pulse energization control may be performed in the entire operation region. However, as in claim 2, the pulse energization control is performed in a control region in which the response characteristic of the VCT to the hydraulic control valve current is slow. Alternatively, or as in claim 3, it is preferable to perform the pulse energization control in a minute displacement control region in which the actual displacement angle of the VCT is minutely displaced in the vicinity of the target displacement angle. In this way, the pulse energization control can be performed only in the region where the responsiveness is poor in the conventional VCT, and the same control can be performed in the other regions.

  Further, as in claim 4, a region where the deviation between the actual displacement angle of the VCT and the target displacement angle is smaller than a threshold value for determining the deviation in the minute displacement control region (pulse energization control region) is defined as a holding control region. In this holding control region, it is preferable to hold the actual displacement angle of the VCT at the target displacement angle by supplying a holding current to the hydraulic control valve. In this way, during the holding control, when the deviation between the actual displacement angle of the VCT and the target displacement angle exceeds the holding control area and enters the minute displacement control area (pulse conduction control area), the pulse conduction control is immediately performed. It is possible to reduce the deviation between the actual displacement angle of the VCT and the target displacement angle, and to improve the convergence and retention of the actual displacement angle to the target displacement angle. As the holding current, a value learned during holding control may be used.

  Further, as in claim 5, a region where the deviation between the actual displacement angle and the target displacement angle of the VCT is larger than the determination threshold value of the deviation in the minute displacement control region (pulse conduction control region) is defined as a high-speed control region. In this high-speed control region, it is preferable to perform feedback control and / or feedforward control of the current of the hydraulic control valve in accordance with the deviation between the actual displacement angle of the VCT and the target displacement angle. In this way, during transient operation in which the target displacement angle changes suddenly and greatly, a large current is continuously supplied to the hydraulic control valve in accordance with the deviation between the actual displacement angle and the target displacement angle, and the VCT is set to the target displacement angle. It can be driven at high speed in the direction of.

  Further, as in claim 6, the VCT displacement amount (advance amount / retard amount) may be controlled by varying the energization time (pulse width) or the number of times of pulse energization. Alternatively, the amount of VCT displacement (advance amount / retard amount) can be controlled even when the current value (pulse height) of pulse energization is varied.

  In this case, the relationship between the energization time / number of pulse energizations and the amount of VCT displacement may be determined in advance by design data or the like, but considering that there are variations in VCT response characteristics due to variations in VCT manufacturing and changes over time. Thus, as in claim 7, the relationship between the energization time or number of pulse energizations and the amount of VCT displacement driven by the pulse energization is learned, and the energization time or number of pulse energizations is set based on the learned value. You may make it do. In this way, it is possible to eliminate control errors due to VCT manufacturing variations and changes over time.

  Further, in order to consider the characteristic that the lower the hydraulic pressure supplied to the VCT, the lower the response speed of the VCT, and the lower the oil temperature, the larger the viscous resistance of the hydraulic oil and the lower the response speed of the VCT. As in Item 8, a learning value related to the energization time or number of pulse energizations may be learned for each operating condition. Here, as operating conditions, for example, hydraulic pressure or oil temperature (viscosity) may be considered. In general, an oil pump that supplies hydraulic pressure to the VCT is driven by engine power, and therefore, there is a relationship that the hydraulic pressure increases as the engine speed increases. Therefore, the engine rotation speed may be used as hydraulic pressure substitute information. Further, since the oil temperature and the engine temperature have a correlation, the engine temperature (cooling water temperature) may be used as substitute information for the oil temperature. If the learning value regarding the energization time or number of times of pulse energization is learned for each operating condition, the accuracy of pulse energization control can be improved.

  The present invention can be applied to various configurations as long as it is a vane type VCT. For example, as in claim 9, the hydraulic supply oil passage and the retard angle of the advance chamber of at least one vane storage chamber Check valves that prevent backflow of hydraulic fluid from each hydraulic chamber (“hydraulic chamber” means either “advance chamber” or “retard chamber”) are provided in the hydraulic supply passage of the chamber. In addition, a drain oil passage that bypasses the check valve is provided in parallel in the hydraulic supply oil passage of each hydraulic chamber, a drain switching valve that is driven by hydraulic pressure is provided in each drain oil passage, and each drain switching The present invention can also be applied to a VCT having a configuration in which a hydraulic switching valve for switching the hydraulic pressure for driving the valve is provided.

  In this VCT with a check valve / drain switching valve, when the VCT is advanced, the drain switching valve on the advance chamber side into which hydraulic fluid flows is closed and the retard chamber on which the hydraulic oil is discharged is closed. When the hydraulic switching valve is controlled to open the drain switching valve and the VCT is retarded, the retardation switching valve on the retarding chamber side into which the hydraulic oil flows is closed and the hydraulic chamber is discharged. The hydraulic pressure switching valve may be controlled so as to open the drain switching valve on the side. In this way, even in the low rotation region where the hydraulic pressure supplied from the hydraulic pressure supply source is low, the reverse flow of oil from the advance chamber is reversed against the torque fluctuation in the retard direction of the vane rotor during the advance operation. While preventing by a stop valve, hydraulic pressure can be efficiently supplied to the advance chamber to improve the advance angle response. Similarly, during the retard operation, the retard angle against the torque fluctuation in the advance direction of the vane rotor is retarded. While preventing back flow of oil from the chamber by a check valve, the hydraulic pressure can be efficiently supplied to the retard chamber and the retard response can be improved.

  In addition, when holding control is performed, both the hydraulic pressure supply to the drain switching valves in both the advance chamber and the retard chamber are stopped, so that both drain switching valves are closed, and the advance chamber and the retard chamber are both closed. What is necessary is just to make it the state which makes both check valves of a corner chamber function. In this state, even if torque fluctuations acting on the vane rotor in the retarding direction and the advancement direction act on the vane rotor due to torque fluctuations that the camshaft receives from the intake and exhaust valves, the hydraulic oil in both the advancement chamber and the retarding chamber Is prevented by a check valve, the hydraulic pressure for holding the vane from both sides is prevented from being lowered, and the holding stability can be improved.

  In the present invention, the hydraulic pressure switching valve for switching the hydraulic pressure for driving the drain switching valve may be provided separately from the hydraulic pressure control valve, or the hydraulic pressure switching valve may be integrated with the hydraulic pressure control valve.

  Specifically, as in claim 10, the first check valve is provided in the hydraulic supply oil passage of the advance chamber in at least one vane storage chamber and prevents the backflow of hydraulic oil from the advance chamber. A first drain switching valve that is provided in a first drain oil passage that bypasses the first check valve and is driven by hydraulic pressure, and a hydraulic supply oil passage for a retard chamber of at least one vane storage chamber Provided in a second check valve for preventing backflow of hydraulic oil from the retard chamber and a second drain oil passage that bypasses the second check valve, and is driven by hydraulic pressure. A second drain switching valve, a first hydraulic control valve for controlling the hydraulic pressure in the advance chamber and the retarded chamber, the first drain switching valve, and the second drain switching valve; It is good also as a structure provided with the 2nd hydraulic control valve which controls the hydraulic pressure to drive. In this configuration, when the VCT is advanced, the advance angle chamber side drain switching valve into which hydraulic fluid flows is closed, and the retarded chamber side drain switching valve from which hydraulic fluid is discharged is opened. When the hydraulic control valve 2 is controlled to retard the VCT, the drain switching valve on the retarding chamber side into which the hydraulic oil flows is closed, and the drain switching valve on the advanced chamber side from which the hydraulic fluid is discharged The second hydraulic control valve may be controlled so as to open.

  In this case, as in the eleventh aspect, the first hydraulic control valve and the second hydraulic control valve can be controlled independently, and the control means includes the actual displacement angle of the VCT and the target displacement. The first control means for controlling the current of the first hydraulic control valve according to the deviation from the angle and the current of the second hydraulic control valve are controlled to control the hydraulic pressure for driving each drain switching valve. It is good also as a structure containing the 2nd control means to do.

  Alternatively, as in claim 12, the shaft for driving the first hydraulic control valve and the second hydraulic control valve is integrated, and the control means controls the current of the hydraulic control valve. Thus, the hydraulic control valve is controlled according to the deviation between the actual displacement angle and the target displacement angle of the VCT, and the second hydraulic control valve is controlled to control the hydraulic pressure for driving each drain switching valve. You may make it control.

  Further, as in claim 13, the first check valve provided in the hydraulic pressure supply oil passage of the advance chamber in at least one vane storage chamber to prevent the backflow of hydraulic oil from the advance chamber, A first drain oil passage that bypasses the first check valve and a hydraulic supply oil passage in at least one retard chamber of the vane storage chamber are provided to prevent backflow of hydraulic oil from the retard chamber. 2 check valves and a second drain oil passage that bypasses the second check valve, and the hydraulic control valve includes the first drain oil passage and the second drain oil passage. It is good also as a structure which integrated the drain oil path control function which opens / closes. In this configuration, when the hydraulic control valve is controlled to advance the VCT, the drain oil passage on the advance chamber side into which the hydraulic oil flows is closed, and the retard chamber side from which the hydraulic oil is discharged When the VCT is controlled to open at a retarded angle, the drain oil path on the retarded chamber side through which the hydraulic oil flows is closed and the advanced chamber side drain from which the hydraulic oil is discharged is controlled. Control may be made so that the oil passage is opened.

  In this case, as in claim 14, the first drain switching valve provided in the first drain oil passage and driven by hydraulic pressure and the second drain oil passage provided in the second drain oil passage and driven by hydraulic pressure. The first drain oil is configured to include a second drain switching valve, and the first drain switching valve is opened / closed by hydraulic control by a drain oil passage control function of the hydraulic control valve. It is preferable that the second drain oil passage is opened / closed by opening / closing the passage and opening / closing the second drain switching valve.

Hereinafter, an embodiment embodying the best mode for carrying out the present invention will be described.
First, the configuration of the vane variable valve timing adjusting mechanism 11 will be described with reference to FIG. The housing 12 of the variable valve timing adjustment mechanism 11 is fastened and fixed with bolts 13 to a sprocket that is rotatably supported on the outer periphery of an intake-side or exhaust-side camshaft (not shown). Thereby, the rotation of the crankshaft of the engine is transmitted to the sprocket and the housing 12 via the timing chain, and the sprocket and the housing 12 rotate in synchronization with the crankshaft. A vane rotor 14 is accommodated in the housing 12 so as to be relatively rotatable, and the vane rotor 14 is fastened and fixed to one end portion of the camshaft by a bolt 15.

  Inside the housing 12, a plurality of vane storage chambers 16 for storing a plurality of vanes 17 on the outer periphery of the vane rotor 14 so as to be relatively rotatable in the advance angle direction and the retard angle direction are formed. The vane 17 is divided into an advance chamber 18 and a retard chamber 19.

  In a state where the hydraulic pressure of a predetermined pressure or higher is supplied to the advance chamber 18 and the retard chamber 19, the vane 17 is held by the hydraulic pressure of the advance chamber 18 and the retard chamber 19, and the housing 12 is rotated by the rotation of the crankshaft. Is transmitted to the vane rotor 14 via hydraulic pressure, and the camshaft is rotationally driven integrally with the vane rotor 14. During engine operation, the hydraulic pressure in the advance chamber 18 and the retard chamber 19 is controlled by the hydraulic control valve 21 to rotate the vane rotor 14 relative to the housing 12, so that the cam shaft displacement angle (cam The valve timing of the intake valve (or exhaust valve) is varied by controlling the axial phase.

  Further, stopper portions 22 and 23 for restricting the relative rotation range of the vane rotor 14 with respect to the housing 12 are formed on both side portions of any one vane 17, and the cam shaft displacement angle (cam) is defined by the stopper portions 22 and 23. The most retarded angle position and the most advanced angle position (axis phase) are regulated. In addition, any one vane 17 is provided with a lock pin 24 for locking the cam shaft displacement angle at a predetermined lock position when the engine is stopped, and the lock pin 24 is provided on the housing 12. By fitting into a hole (not shown), the displacement angle of the camshaft is locked at a predetermined locking position. This lock position is set to a position suitable for starting (for example, a substantially intermediate position in the adjustable range of the cam shaft displacement angle).

  Oil (operating oil) in the oil pan 26 is supplied to the hydraulic control circuit of the variable valve timing adjustment mechanism 11 by the oil pump 27 via the hydraulic control valve 21. The hydraulic control circuit is discharged from a hydraulic supply oil passage 28 that supplies oil discharged from the advance pressure port of the hydraulic control valve 21 to the plurality of advance chambers 18 and a retard pressure port of the hydraulic control valve 21. A hydraulic supply oil passage 29 for supplying oil to the plurality of retarding chambers 19 is provided.

  The hydraulic supply oil passage 28 of the advance chamber 18 and the hydraulic supply oil passage 29 of the retard chamber 19 are provided with check valves 30 and 31 for preventing backflow of hydraulic oil from the chambers 18 and 19, respectively. ing. In this embodiment, check valves 30 and 31 are provided only for the hydraulic supply oil passages 28 and 29 of the advance chamber 18 and the retard chamber 19 of one vane storage chamber 16. Of course, the check valves 30 and 31 may be provided in the hydraulic supply oil passages 28 and 29 in the advance chamber 18 and the retard chamber 19 of the two or more vane storage chambers 16, respectively.

  Drain oil passages 32 and 33 that bypass the check valves 30 and 31 are provided in parallel in the hydraulic supply oil passages 28 and 29 of the chambers 18 and 19, respectively. The drain oil passages 32 and 33 are respectively provided with drains. Switching valves 34 and 35 are provided. Each drain switching valve 34, 35 is constituted by a spool valve that is driven in the valve closing direction by the hydraulic pressure (pilot pressure) supplied from the hydraulic control valve 21, and is opened by the springs 41, 42 when no hydraulic pressure is applied. Held in position. When the drain switching valves 34 and 35 are opened, the drain oil passages 32 and 33 are opened, and the check valves 30 and 31 do not function. When the drain switching valves 34 and 35 are closed, the drain oil passages 32 and 33 are closed, and the functions of the check valves 30 and 31 are effectively activated, so that backflow of oil from the hydraulic chambers 18 and 19 is prevented. Thus, the hydraulic pressure in the hydraulic chambers 18 and 19 is maintained.

  Since the drain switching valves 34 and 35 do not require electrical wiring, the drain switching valves 34 and 35 are compactly assembled together with the check valves 30 and 31 to the vane rotor 14 inside the variable valve timing adjustment mechanism 11. As a result, the drain switching valves 34 and 35 are arranged near the hydraulic chambers 18 and 19, and the drain oil passages 32 and 33 are opened with good response near the hydraulic chambers 18 and 19 during advance / retard operation. It can be closed.

  On the other hand, the hydraulic control valve 21 is constituted by a spool valve driven by a linear solenoid 36, and an advance / retarding hydraulic control function 37 for controlling the hydraulic pressure supplied to the advance chamber 18 and the retard chamber 19, and each drain. A drain switching control function 38 (hydraulic switching valve) for switching the hydraulic pressure for driving the switching valves 34 and 35 is integrated. A current value (control duty) energized to the linear solenoid 36 of the hydraulic control valve 21 is controlled by an engine control circuit (hereinafter referred to as “ECU”) 43.

  The ECU 43 calculates the actual valve timing (actual displacement angle) of the intake valve (or exhaust valve) based on the output signals of the crank angle sensor 44 and the cam angle sensor 45, and operates the engine such as an intake pressure sensor and a water temperature sensor. The target valve timing (target displacement angle) of the intake valve (or exhaust valve) is calculated based on the outputs of various sensors that detect the state. Then, the ECU 43 controls the control current of the hydraulic control valve 21 of the variable valve timing adjustment mechanism 11 so as to make the actual valve timing coincide with the target valve timing by executing the routines shown in FIGS. . As a result, the oil pressure in the advance chamber 18 and the retard chamber 19 is controlled to rotate the vane rotor 14 relative to the housing 12, thereby changing the cam shaft displacement angle and setting the actual valve timing to the target valve timing. Match.

  By the way, when the intake valve and the exhaust valve are driven to open and close during engine operation, the torque fluctuation received by the camshaft from the intake valve and the exhaust valve is transmitted to the vane rotor 14, thereby causing the retard direction and advance angle with respect to the vane rotor 14. Torque fluctuation in the direction acts. Thus, when the vane rotor 14 receives torque fluctuation in the retarding direction, the hydraulic oil in the advance chamber 18 receives pressure that is pushed out from the advance chamber 18, and when the vane rotor 14 receives torque fluctuation in the advance direction, the retard angle The hydraulic oil in the chamber 19 receives a pressure pushed out from the retard chamber 19. For this reason, in the low rotation region where the discharge hydraulic pressure of the oil pump 27 as the hydraulic pressure supply source is low, if there is no check valve 30, 31, the hydraulic pressure is supplied to the advance chamber 18 to advance the displacement angle of the camshaft. Even when trying to do so, as indicated by the dotted line in FIG. 3, the vane rotor 14 is pushed back in the retarded direction due to the torque fluctuation, and there is a problem that the response time until reaching the target displacement angle becomes long. .

  On the other hand, in this embodiment, a check valve that prevents backflow of oil from the chambers 18 and 19 into the hydraulic supply oil passage 28 of the advance chamber 18 and the hydraulic supply oil passage 29 of the retard chamber 19 respectively. 30 and 31, and drain oil passages 32 and 33 that bypass the check valves 30 and 31 are provided in parallel in the hydraulic supply oil passages 28 and 29 of the chambers 18 and 19, respectively. In addition, drain switching valves 34 and 35 are provided, respectively. As a result, as shown in FIG. 2, the hydraulic pressures in the chambers 18 and 19 are controlled as follows according to the retarding operation, holding operation, and advancement operation.

[Delay operation]
During the retard operation that retards the actual valve timing toward the target valve timing on the retard side, the hydraulic pressure supply to the drain switching valve 34 in the advance chamber 18 is stopped, so that the drain switching valve in the advance chamber 18 is stopped. The valve 34 is opened so that the check valve 30 of the advance chamber 18 does not function, and the hydraulic pressure is applied from the hydraulic switch valve 38 to the drain switch valve 35 of the retard chamber 19, thereby draining the retard chamber 19. The switching valve 35 is closed to make the check valve 31 of the retard chamber 19 function. As a result, even when the hydraulic pressure is low, the hydraulic pressure is efficiently supplied to the retarded angle chamber 19 while preventing the backflow of oil from the retarded angle chamber 19 by the check valve 31 against the torque fluctuation in the advanced angle direction of the vane rotor 14. To improve retardation response.

[Holding operation]
During the holding operation for maintaining the actual valve timing at the target valve timing, both the drain switching can be performed by applying hydraulic pressure from the hydraulic switching valve 38 to the drain switching valves 34 and 35 of both the advance chamber 18 and the retard chamber 19. The valves 34 and 35 are both closed so that the check valves 30 and 31 of both the advance chamber 18 and the retard chamber 19 are made to function. In this state, even if torque fluctuations acting on the vane rotor 14 in the retarding direction and the advancement direction act on the vane rotor 14 due to torque fluctuations received by the camshaft from the intake valve or the exhaust valve, The reverse flow of the oil is prevented by the check valve 31, and the hydraulic pressure for holding the vane 17 from both sides is prevented from being lowered to improve the holding stability.

[Advance operation]
During the advance operation for advancing the actual valve timing toward the target valve timing on the advance side, the hydraulic pressure is applied from the hydraulic switch valve 38 to the drain switch valve 34 of the advance chamber 18, thereby draining the advance chamber 18. The switching valve 34 is closed to make the check valve 30 of the advance chamber 18 function, and the hydraulic pressure supply to the drain switching valve 35 of the retard chamber 19 is stopped, so that the drain of the retard chamber 19 is stopped. The switching valve 35 is opened so that the check valve 31 of the retard chamber 19 does not function. Thus, even when the hydraulic pressure is low, the hydraulic pressure is efficiently supplied to the advance chamber 18 while preventing the backflow of oil from the advance chamber 18 by the check valve 30 against the torque fluctuation in the retard angle direction of the vane rotor 14. To improve the lead angle response.

  Next, response characteristics of the variable valve timing adjustment mechanism 11 (hereinafter referred to as “VCT”) will be described with reference to FIG. FIG. 4 shows an example of a VCT response characteristic obtained by measuring the relationship between the control current value of the hydraulic control valve 21 (hereinafter referred to as “OCV”) and the VCT response speed.

  In this embodiment, since the check valves 30, 31 and the drain switching valves 34, 35 are provided in both the advance chamber 18 and the retard chamber 19, the VCT response speed is linear with respect to the change in the OCV current value. The VCT response speed changes suddenly at two locations by switching the opening / closing of the drain switching valves 34 and 35 without changing. In the VCT response characteristics of FIG. 4, the responsiveness sudden change point on the retarded angle side is a point where the drain switching valve 34 of the advance chamber 18 is switched from closed to open, and the sudden response point on the advanced angle side is delayed. The drain switching valve 35 of the corner chamber 19 is switched from the closed valve to the opened valve. The holding operation is performed in a region where the gradient of the change in the VCT response speed between the responsiveness sudden change point on the retard side and the responsive sudden change point on the advance side is small.

  As shown in FIG. 4, the response characteristic of the VCT with respect to the OCV current is not linear, and the response is slow in the vicinity of the holding current that holds the VCT at a certain position (the point where the response speed suddenly changes from the retarded angle side). There is a region where the gradient of the change in the VCT response speed between the corner side sudden response change point is small. In this region, even if the OCV current is feedback-controlled according to the deviation between the target displacement angle and the actual displacement angle, the VCT movement is slow and the VCT cannot be driven in the direction of the target displacement angle with good response.

  As a countermeasure, if the feedback gain is increased too much, an overshoot occurs and the convergence of the actual displacement angle to the target displacement angle deteriorates, causing problems such as deterioration of engine combustion.

  Therefore, in this embodiment, the region where the response characteristic of the VCT to the OCV current is slow (region where the gradient of the change in the VCT response speed between the retarded sudden response point and the advanced sudden response point is small). Then, when performing minute displacement control in which the actual displacement angle (actual advance angle amount) of the VCT is minutely displaced in the vicinity of the target displacement angle (target advance angle amount), the VCT is targeted by energizing the hydraulic control valve 21 with a pulse. “Pulse energization control” is performed to drive in the direction of the displacement angle. As described above, if the hydraulic control valve 21 is energized with a pulse, even if a relatively large pulse current is applied, the energization time is very small, so that the VCT displacement amount (advance amount / retard angle amount) is also minute. For this reason, if the hydraulic control valve 21 is energized with pulses, the VCT can be driven more responsively than before without causing the problem of overshoot.

  In this case, a region where the deviation between the actual displacement angle and the target displacement angle of the VCT is smaller than the determination threshold value of the deviation in the minute displacement control region (pulse energization control region) is defined as a retention control region. A holding current is supplied to the hydraulic control valve 21 to hold the actual displacement angle of the VCT at the target displacement angle. In this way, during the holding control, when the deviation between the actual displacement angle of the VCT and the target displacement angle exceeds the holding control area and enters the minute displacement control area (pulse conduction control area), the pulse conduction control is immediately performed. It is possible to reduce the deviation between the actual displacement angle of the VCT and the target displacement angle, and to improve the convergence and retention of the actual displacement angle to the target displacement angle. As the holding current, a value learned during holding control may be used.

  In addition, a region where the deviation between the actual displacement angle of VCT and the target displacement angle is larger than the determination threshold value of the deviation in the minute displacement control region (pulse conduction control region) is defined as a high-speed control region. The current of the hydraulic control valve 21 is feedback controlled and / or feedforward controlled in accordance with the deviation between the actual displacement angle and the target displacement angle. In this way, during transient operation in which the target displacement angle changes rapidly and drastically, a large current is continuously supplied to the hydraulic control valve 21 in accordance with the deviation between the actual displacement angle and the target displacement angle, and VCT is set to the target displacement angle. It can be driven at high speed in the direction.

  The VCT control of the present embodiment described above is executed by the ECU 43 according to the routines of FIGS. 5 to 7, and functions as control means in the claims are realized. The processing contents of these routines will be described below.

[VCT control routine]
The VCT control routine of FIG. 5 is executed at a predetermined cycle (for example, 5 ms cycle) during engine operation. When this routine is started, first, in step 101, operating conditions (for example, engine speed, load, cooling water temperature, etc.) are detected, and in the next step 102, VCT control execution conditions are established based on the detected operating conditions. It is determined whether or not. As a result, if it is determined that the VCT control execution condition is not satisfied, this routine is terminated without performing the subsequent processing. When the VCT control is not executed, the target advance amount VVT is maintained at 0 (most retarded position).

  On the other hand, if it is determined in step 102 that the VCT control execution condition is satisfied, the process proceeds to step 103, where the output signal of the crank angle sensor 44 and the cam angle sensor 45 that is generated subsequently are output. The actual advance amount VTA (advance amount from the most retarded position to the current position) is calculated from the phase difference with the output signal, and in the next step 104, the current operating conditions (engine speed, load, etc.) Accordingly, the target advance amount VTT is calculated from a map or the like.

  Thereafter, the routine proceeds to step 105, where a VCT control mode determination routine of FIG. 6 described later is executed, and the current VCT control mode is any of the control modes of holding control, minute displacement control (pulse energization control), and high-speed control. Determine if there is. Thereafter, the routine proceeds to step 106, where an OCV target current calculation routine of FIG. 7 described later is executed to calculate the OCV target current iVVT according to the current VCT control mode. In the next step 107, the control duty for controlling the control current of the hydraulic control valve 21 (OCV) to the OCV target current iVVT is calculated, and this routine is finished.

[VCT control mode determination routine]
The VCT control mode determination routine of FIG. 6 is a subroutine executed in step 105 of the VCT control routine of FIG. When this routine is started, it is first determined in step 201 whether or not the target advance amount VTT is 0 (most retarded position), and if the target advance amount VTT is 0 (most retarded position). For example, it is determined that the VCT control (high speed control, minute displacement control, holding control) is not executed, and the process proceeds to step 202, where all of the high speed control execution flag XFB, the minute displacement control execution flag XPLS, and the holding control execution flag XKP are set to “0”. Cleared to "" to end this routine.

  On the other hand, if it is determined in step 201 that the target advance amount VTT is 0 (most retarded position), the process proceeds to step 203 and the absolute value of the deviation between the actual advance amount VTA and the target advance amount VTT. | VTA−VTT | is compared with the determination threshold value KKP of the holding control region, and if the absolute value | VTA−VTT | of the advance amount deviation is equal to or smaller than the determination threshold value KKP of the holding control region, the current VCT It is determined that the control mode is the holding control mode, and the process proceeds to step 205 where the high speed control execution flag XFB and the minute displacement control execution flag XPLS are cleared to “0” and only the holding control execution flag XKP is set to “1”. Set and end this routine.

  On the other hand, if it is determined in step 203 that the absolute value | VTA−VTT | of the advance amount deviation is larger than the determination threshold value KKP of the holding control region, the current VCT control mode is set to the holding control mode. Therefore, the process proceeds to step 204, where the absolute value | VTA−VTT | of the advance amount deviation is compared with the determination threshold value KPLS of the minute displacement control region, and the absolute value | VTA− of this advance amount deviation is determined. When VTT | is equal to or smaller than the determination threshold value KPLS of the minute displacement control region (that is, when KKP <| VTA−VTT | ≦ KPLS), it is determined that the current VCT control mode is the minute displacement control mode, Proceeding to step 206, the high speed control execution flag XFB and the holding control execution flag XKP are cleared to “0”, and only the minute displacement control execution flag XPLS is set to “1”. To end the emissions.

  If it is determined in step 204 that the absolute value | VTA−VTT | of the advance angle deviation is larger than the determination threshold value KPLS of the minute displacement control region, the current VCT control mode is the high-speed control mode. In step 207, only the high speed control execution flag XFB is set to “1”, the minute displacement control execution flag XPLS and the holding control execution flag XKP are cleared to “0”, and this routine is finished.

[OCV target current calculation routine]
The OCV target current calculation routine of FIG. 7 is a subroutine executed in step 106 of the VCT control routine of FIG. When this routine is started, first, at step 301, it is determined whether any one of the holding control execution flag XKP, the minute displacement control execution flag XPLS, and the high-speed control execution flag XFB is set to “1”. If all the flags are “0”, it is determined that VCT control (holding control, minute displacement control, high speed control) is not executed, and the routine proceeds to step 302 where the OCV target current iVVT is set to 0 (most retarded position). At the same time, the pulse energization time counter CPLS is cleared to “0”, and this routine ends. The OCV target current iVVT at the most retarded angle position may be a current value other than 0 as long as the VCT does not advance.

  On the other hand, if it is determined in step 301 that one of the flags is set to “1”, the process proceeds to step 303 where the holding control execution flag XKP is “1” and the pulse energization time counter is set. It is determined whether CPLS is “0”. If the determination result is “Yes”, the process proceeds to step 304 where the OCV target current iVVT is set to the holding current, the holding control is executed, and the pulse energization time counter CPLS is maintained at “0”. Here, the value learned during the holding control may be used as the holding current.

  This holding current learning is performed when, for example, if the behavior in which the actual advance amount VTA exceeds the holding control region in the advance direction occurs several times during the holding control, the holding current learning value is more advanced than the appropriate value. If it is determined that the holding current learning value is corrected by a predetermined value in the retarding direction, and the actual advance amount VTA exceeds the holding control region in the retarding direction several times, It may be determined that the holding current learning value is deviated from the appropriate value in the retarding direction, and the process of correcting the holding current learning value by a predetermined value in the advance direction may be repeated. This holding current learning value is learned for each operating condition (oil pressure, oil temperature, engine rotation speed, cooling water temperature, etc., which are information correlated with these) or for each region of the target advance amount VTT, and is stored in a backup RAM of the ECU 43 or the like. Update storage may be performed in a rewritable nonvolatile memory.

  On the other hand, if “No” is determined in step 202, it is determined that the holding control is not executed, the process proceeds to step 305, and it is determined whether or not the minute displacement control execution flag XPLS is set to “1”. If the minute displacement control execution flag XPLS is “1”, minute displacement control (pulse energization control) is executed as follows.

  First, in step 306, it is determined whether or not the pulse energization time counter CPLS is “0”. If the pulse energization time counter CPLS is “0”, the process proceeds to step 307 to start minute displacement control. The initial value of the pulse energization time counter CPLS is set according to the current operating conditions (oil pressure, oil temperature or engine speed, coolant temperature, etc., which are information correlated with these). The initial value of the pulse energization time counter CPLS is an initial value for setting the pulse energization time necessary to return the actual advance angle amount VTA to the vicinity of the target advance angle amount VTT according to the current operating conditions. You may make it learn for every condition, and make it update-store in the rewritable non-volatile memory of ECU43.

  If it is determined in the above step 306 that the pulse energization time counter CPLS is not “0”, it is determined that the pulse energization control is being executed, and the process proceeds to step 308 where the pulse energization time counter CPLS is decremented by one and the pulse energization time is determined. Measure.

  After that, the process proceeds to step 309, where the count value of the pulse energization time counter CPLS is compared with the end energization determination value KPSLON of the pulse energization control. If the count value of the pulse energization time counter CPLS is equal to or greater than the end energization determination value KPSLON of the pulse energization control Then, it is determined that it is not the end timing of the pulse energization control, and the process proceeds to step 310, where the VCT drive direction is determined from the magnitude relationship between the actual advance angle amount VTA and the target advance angle amount VTT. At this time, if the actual advance amount VTA is larger than the target advance amount VTT, it is determined that the VCT is driven in the retard direction, and the process proceeds to Step 311 to set the OCV target current iVVT of the pulse energization control to the retard side set value. Set to KIVTRE and drive the VCT in the retard direction. Here, the retard side set value KIVTRE may be set, for example, to the retard side limit current value (0 mA) or a current value close thereto, or may be set based on the holding current learning value. (For example, it may be set to a current value smaller than the holding current learning value by a predetermined value).

  On the other hand, if the actual advance amount VTA is smaller than the target advance amount VTT, it is determined that the VCT is driven in the advance direction, and the process proceeds to step 312 to set the OCV target current iVVT of the pulse energization control to the advance side set value KIVTAD. And the VCT is driven in the advance direction. Here, the advance side set value KIVTAD may be set to, for example, an advance side limit current value (OCV maximum allowable current) or a current value close thereto, or set based on the holding current learning value. (For example, the current value may be set to a predetermined value larger than the holding current learning value).

  Thereafter, when the count value of the pulse energization time counter CPLS falls below the pulse energization control end determination value KPSLON (the time when “No” is first determined in step 309), the end timing of the pulse energization control (holding control) ), The process proceeds to step 313, where the OCV target current iVVT is set to the holding current and the holding control is started.

  If it is determined “No” in both step 303 and step 305, it is determined that the current VCT control mode is the high-speed control mode (high-speed control execution flag XFB = 1), and the process proceeds to step 314. The energization time counter CPLS is cleared to “0”, and in the next step 315, the OCV target current iVVT is set by feedback control such as PD control in accordance with the deviation between the actual displacement angle VTA of VCT and the target displacement angle VTT.

  At this time, the OCV target current iVVT may be set by feedforward control according to the deviation between the actual displacement angle VTA of the VCT and the target displacement angle VTT. Of course, the OCV target current is combined by combining the feedback control and the feedforward control. It goes without saying that iVVT may be set.

  An example of the VCT control of the present embodiment described above will be described with reference to the time chart of FIG. In the control example of FIG. 8, the deviation between the actual advance amount VTA and the target advance amount VTT is determined in the hold control region (determined when the hold control for holding the actual advance amount VTA near the target advance amount VTT is being executed. The control behavior when the threshold value KKP) is exceeded is shown.

  During the holding control, the OCV target current iVVT is set to the holding current, and the actual advance amount VTA is held in the vicinity of the target advance amount VTT. Then, during the execution of the holding control, when the deviation between the actual advance amount VTA and the target advance amount VTT exceeds the hold control region (determination threshold KKP) and enters the minute displacement control region, t1, t3, At t5, the holding control execution flag XKP is reversed from “1” to “0” to end the holding control, and at the same time, the minute displacement control execution flag XPLS is reversed from “0” to “1” to perform minute displacement control (pulse Start energization control).

  In this minute displacement control (pulse energization control), when the actual advance amount VTA is shifted more than the determination threshold value KKP to the retard side than the target advance amount VTT (t3 to t4, t5 to t6), the OCV The target current iVVT is set to the advance side set value KIVTAD, and the VCT is driven in the advance direction. Further, when the actual advance amount VTA is deviated from the target advance amount VTT to the advance side by the determination threshold value KKP or more (t1 to t2), the OCV target current iVVT is set to the retard side set value KIVTRE. Then, the VCT is driven in the retard direction.

  At the start time (t1, t3, t5) of the minute displacement control, the pulse energizing time counter CPLS of the pulse energizing time counter CPLS is determined according to the current operating conditions (oil pressure, oil temperature, engine speed, coolant temperature, etc., which are information correlated with these). An initial value is set, and the count value of the pulse energization time counter CPLS is decremented at a predetermined calculation cycle. When the count value of the pulse energization time counter CPLS falls below the pulse energization control end determination value KPSLON (t2, t4, t6), it is determined that the actual advance amount VTA has returned to the vicinity of the target advance amount VTT. Returning to the holding control, the OCV target current iVVT is set to the holding current, and the actual advance angle amount VTA is held at the target advance angle amount VTT.

  According to the present embodiment described above, when performing minute displacement control in which the actual advance angle amount VTA of the VCT is slightly displaced in the vicinity of the target advance angle amount VTT, the hydraulic control valve 21 is energized with a pulse to cause the VCT to reach the target advance amount. Since the pulse is driven in the direction of the angular amount VTT, the VCT can be driven more responsively in the direction of the target advance amount VTT than before without causing the problem of overshoot.

  In this embodiment, the pulse energization time (pulse width) necessary for returning the actual advance angle amount VTA to the vicinity of the target advance angle amount VTT by the pulse energization control is set according to the operating conditions. The number of energizations may be set according to the operating conditions.

  Further, the present invention is a region where the response characteristic of the VCT to the OCV current is slow (a region where the gradient of the VCT response speed change between the responsiveness sudden change point on the retarded angle side and the rapid response point on the advanced angle side is small). It is determined whether or not it exists based on the OCV target current iVVT, and when it is determined that the response characteristic of the VCT is slow, the deviation between the actual advance amount VTA and the target advance amount VTT is the holding control region (determination Every time the threshold value KKP) is exceeded, minute displacement control (pulse energization control) may be performed.

  Further, according to the present invention, the hydraulic pressure switching valve 38 for switching the hydraulic pressure for driving the drain switching valves 34 and 35 may be provided separately from the hydraulic control valve 21, but in this embodiment, the hydraulic pressure switching valve 38 is provided. Is integrated with the hydraulic control valve 21. Therefore, there is an advantage that requirements for reduction in the number of parts, cost reduction, and compactness can be satisfied.

  The present invention is not limited to the configuration of the variable valve timing adjusting mechanism 11 shown in FIG. 1, and may be applied to, for example, the variable valve timing adjusting mechanisms 71 and 72 of other embodiments shown in FIG. 9 or FIG. it can.

  The variable valve timing adjusting mechanism 71 shown in FIG. 9 is different from the variable valve timing adjusting mechanism 11 shown in FIG. In FIG. 9, the same components as those in FIG.

  First, the hydraulic control valve 21 in FIG. 1 drives the advance / retard hydraulic control function 37 and the drain switching control function 38 by a single linear solenoid 36. In FIG. 9, the advance / retard hydraulic control is performed. Solenoids 36 and 51 are respectively provided in the first hydraulic control valve 37 that realizes the function and the second hydraulic control valve 38 that realizes the drain switching control function, and the solenoids 36 and 51 are respectively connected to different ECUs 43 and 52 (first 1 control means and second control means). One ECU 43 controls the current of the first hydraulic control valve 37 according to the deviation between the VCT actual displacement angle and the target displacement angle, and the other ECU 52 controls the current of the second hydraulic control valve 38. The hydraulic pressure for driving the drain switching valves 34 and 35 is controlled.

  As for the drain switching valves 34 and 35, in FIG. 1, when a hydraulic pressure is not applied, a so-called normally open type (normally open type) switching valve that is held in a valve open position by springs 41 and 42 is used. Yes. On the other hand, in FIG. 9, a so-called normally closed type (normally closed type) switching valve that is held in a closed position by springs 41 and 42 when hydraulic pressure is not applied is used. Accordingly, the drain switching control function 38 is configured to supply hydraulic pressure when the drain switching valves 34 and 35 are closed in FIG. 1, but in FIG. 9, the drain switching valves 34 and 35 are closed. In this case, the hydraulic pressure supply is stopped.

  Further, in FIG. 1, check valves 30 and 31 and drains are provided in the hydraulic pressure supply passages 28 and 29 corresponding to the advance chamber 18 and the retard chamber 19 of one vane storage chamber 16 partitioned by one vane 17. In FIG. 9, the switching valves 34 and 35 are provided. In FIG. 9, the hydraulic supply passage 28 for the advance chamber 18 of one vane storage chamber 16 and the hydraulic supply passage 29 for the retard chamber 19 of another vane storage chamber 16 are provided. Check valves 30 and 31 and drain switching valves 34 and 35 are provided.

  In this configuration, during the holding operation for maintaining the VCT displacement angle at the target displacement angle, the drain switching valves 34 and 35 on both the advance chamber 18 side and the retard chamber 19 side are closed to retard the advance chamber 18 side. The second hydraulic control valve 38 is controlled so that both check valves 30 and 31 on the corner chamber 19 side function effectively to prevent backflow of hydraulic oil from the advance chamber 18 and the retard chamber 19. Then, the control current of the first hydraulic control valve 37 that controls the hydraulic pressure supplied to the variable valve timing adjusting mechanism 71 is controlled to a predetermined holding current.

On the other hand, when the variable valve timing adjusting mechanism 71 is advanced, the drain switching valve on the advance chamber side through which hydraulic oil flows is closed and the drain switching valve on the retard chamber side from which hydraulic oil is discharged is opened. When the second hydraulic control valve 38 is controlled and the variable valve timing adjusting mechanism 71 is retarded, the drain switching valve on the retard chamber side into which the hydraulic oil flows is closed and the hydraulic oil is discharged. The second hydraulic control valve 38 is controlled so as to open the drain switching valve on the corner chamber side. In short, during the advance / retard operation, either one of the advance chamber 18 side or the retard chamber 19 side drain switching valve 34 or 35 is opened according to the displacement direction, and either one of the check valves is opened. By controlling the second hydraulic control valve 38 so that 30 or 31 does not function, and by controlling the control current of the first hydraulic control valve 37 to vary the hydraulic pressure supplied to the variable valve timing adjustment mechanism 71. The VCT displacement angle is displaced toward the target displacement angle.
The present invention can also be applied to the variable valve timing adjusting mechanism 71 of FIG. 9 configured as described above.

  Next, the configuration of the variable valve timing adjusting mechanism 72 in FIG. 10 will be described focusing on the differences from FIG. Also in FIG. 10, the same reference numerals are given to the same components as in FIG.

  First, in FIG. 1, there are two valves, an oil path switching valve for the advance / retard hydraulic control function 37 and an oil path switching valve for the drain switching control function 38. On the other hand, in FIG. 10, a single hydraulic control valve 60 is configured to achieve the advance / retard hydraulic pressure control function and the drain switching control function. For this purpose, the hydraulic pressure supply passages 28 and 29 are branched between the hydraulic pressure control valve 60 and the check valves 30 and 31, and are connected to the drain switching valves 34 and 35, respectively.

  In this configuration, during the holding operation for holding the VCT displacement angle at the target displacement angle, the control current of the hydraulic control valve 60 is controlled to a predetermined holding current, so that both the advance chamber 18 side and the retard chamber 19 side are controlled. The drain switching valves 34 and 35 are closed so that the check valves 30 and 31 on both the advance chamber 18 side and the retard chamber 19 side function effectively so that the hydraulic oil from the advance chamber 18 and the retard chamber 19 is discharged. Control is performed to prevent backflow, and the hydraulic pressure supplied to the variable valve timing adjustment mechanism 72 is controlled.

  On the other hand, during the advance / retard operation that displaces the VCT displacement angle in the advance direction or the retard direction, the control current of the hydraulic control valve 60 is controlled, and the advance chamber 18 side is controlled according to the displacement direction. Control is made so that either one of the check valves 30 or 31 does not function by opening one of the drain switching valves 34 or 35 on the retarding chamber 19 side, and the hydraulic pressure supplied to the variable valve timing adjusting mechanism 72 is variable. By doing so, the VCT displacement angle is displaced toward the target displacement angle.

  The present invention can also be applied to the variable valve timing adjusting mechanism 72 of FIG. 10 configured as described above.

It is a figure which shows roughly the variable valve timing adjustment mechanism and its hydraulic control circuit in one Example of this invention. It is a figure for demonstrating retardation operation | movement, holding | maintenance operation | movement, and advance angle operation | movement of a variable valve timing adjustment mechanism. It is a characteristic view for demonstrating the difference in the VCT response speed at the time of advance operation by the presence or absence of a check valve. It is a characteristic view which shows an example of the response characteristic of a variable valve timing adjustment mechanism with a check valve. It is a flowchart explaining the flow of a process of a VCT control routine. It is a flowchart explaining the flow of a process of VCT control mode determination routine. It is a flowchart explaining the flow of a process of OCV target current calculation routine. It is a time chart explaining an example of VCT control. It is a figure which shows schematically the variable valve timing adjustment mechanism in the other Example (the 1) of this invention, and its hydraulic control circuit. It is a figure which shows schematically the variable valve timing adjustment mechanism in the other Example (the 2) of this invention, and its hydraulic control circuit.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Variable valve timing adjustment mechanism, 12 ... Housing, 14 ... Vane rotor, 16 ... Vane storage chamber, 17 ... Vane, 18 ... Advance chamber, 19 ... Delay chamber, 21 ... Hydraulic control valve, 24 ... Lock pin, 27 ... Oil pump, 28, 29 ... Hydraulic supply oil passage, 30, 31 ... Check valve, 32, 33 ... Drain oil passage, 34, 35 ... Drain switching valve, 37 ... Advance / retard hydraulic control function (first Hydraulic control valve), 38 ... drain switching control function (hydraulic switching valve, second hydraulic control valve), 43 ... ECU (control means, first control means), 44 ... crank angle sensor, 45 ... cam angle sensor 52 ... ECU (second control means), 60 ... hydraulic control valve, 71, 72 ... variable valve timing adjustment mechanism

Claims (14)

A plurality of vane storage chambers formed in a housing of a vane type variable valve timing adjustment mechanism (hereinafter referred to as “VCT”) are divided into an advance chamber and a retard chamber by the vanes, respectively. A vane type control valve comprising: a hydraulic control valve that controls the hydraulic pressure and the hydraulic pressure of the retard chamber; and a control unit that controls the current of the hydraulic control valve in accordance with a deviation between the actual displacement angle and the target displacement angle of the VCT. In the control device of the variable valve timing adjustment mechanism,
The control means controls the vane type variable valve timing adjustment mechanism to perform pulse energization control for driving the VCT in a direction of a target displacement angle by energizing the hydraulic control valve with pulses.   2. The vane variable valve timing adjustment mechanism according to claim 1, wherein the control unit performs the pulse energization control in a control region in which a response characteristic of the VCT with respect to a current of the hydraulic control valve becomes slow. Control device.   The vane variable valve according to claim 1 or 2, wherein the control means performs the pulse energization control in a minute displacement control region in which the actual displacement angle of the VCT is minutely displaced in the vicinity of a target displacement angle. Control device for timing adjustment mechanism.   The control means sets a region in which the deviation between the actual displacement angle of the VCT and the target displacement angle is smaller than a threshold value for determining the deviation in the minute displacement control region as the holding control region. 4. The control device for a vane type variable valve timing adjusting mechanism according to claim 3, wherein a holding current is supplied to the control valve to hold the actual displacement angle of the VCT at a target displacement angle.   The control means sets a region in which a deviation between the actual displacement angle and the target displacement angle of the VCT is larger than a determination threshold value of the deviation in the minute displacement control region as a high-speed control region. 5. The vane type variable valve timing adjustment according to claim 3, wherein the current of the hydraulic control valve is feedback-controlled and / or feedforward-controlled in accordance with a deviation between an actual displacement angle and a target displacement angle. Control device for the mechanism.   6. The control of a vane type variable valve timing adjusting mechanism according to claim 1, wherein the control means controls the amount of VCT displacement by varying the energization time or number of times of the pulse energization. apparatus.   The control means learns the relationship between the energization time or number of times of pulse energization and the amount of VCT displacement driven by the pulse energization, and sets the energization time or number of times of pulse energization based on the learned value. The control device for a vane type variable valve timing adjusting mechanism according to claim 6.   The control device of the vane type variable valve timing adjusting mechanism according to claim 7, wherein the control means learns the learning value for each operating condition. In each of the hydraulic chambers (the “hydraulic chamber” is either the “advance chamber” or the “retard chamber”), the hydraulic supply fluid passage of the advance chamber and the retard chamber of the at least one vane storage chamber are respectively provided. A check valve that prevents backflow of hydraulic oil from the hydraulic oil supply line, and a drain oil path that bypasses the check valve is provided in parallel in each hydraulic chamber oil supply path. In addition to providing a drain switching valve that is driven by hydraulic pressure on the road, a hydraulic switching valve that switches the hydraulic pressure that drives each drain switching valve is provided,
When the VCT is advanced, the control means closes the advance chamber side drain switching valve through which hydraulic oil flows in and opens the retarded chamber side drain switching valve from which hydraulic fluid is discharged. When the hydraulic switching valve is controlled to retard the VCT, the drain switching valve on the retarding chamber side into which the hydraulic oil flows is closed, and the drain switching valve on the advanced chamber side through which the hydraulic fluid is discharged. 9. The control device for a vane type variable valve timing adjustment mechanism according to claim 1, wherein the hydraulic pressure switching valve is controlled to open. A first check valve that is provided in a hydraulic pressure supply oil passage of the advance chamber in at least one vane storage chamber and that prevents backflow of hydraulic oil from the advance chamber, and bypasses the first check valve. A first drain switching valve provided in the first drain oil passage and driven by hydraulic pressure, and provided in a hydraulic supply oil passage in the retard chamber of the at least one vane storage chamber, and hydraulic oil from the retard chamber A second check valve for preventing the backflow of the second check valve, a second drain switching valve provided in a second drain oil passage that bypasses the second check valve, and driven hydraulically,
A first hydraulic control valve that controls the hydraulic pressure of the advance chamber and the hydraulic pressure of the retard chamber;
A second hydraulic control valve that controls a hydraulic pressure that drives the first drain switching valve and the second drain switching valve;
When the VCT is advanced, the control means closes the advance chamber side drain switching valve through which hydraulic oil flows in and opens the retarded chamber side drain switching valve from which hydraulic fluid is discharged. When the second hydraulic control valve is controlled and the VCT is retarded, the retard chamber side drain switching valve for allowing the hydraulic oil to flow in is closed, and the advance chamber side drain from which the hydraulic oil is discharged. The control device for a vane type variable valve timing adjusting mechanism according to any one of claims 1 to 8, wherein the second hydraulic control valve is controlled so as to open a switching valve. The first hydraulic control valve and the second hydraulic control valve are controllable independently,
The control means includes a first control means for controlling a current of the first hydraulic control valve in accordance with a deviation between an actual displacement angle and a target displacement angle of the VCT, and a current of the second hydraulic control valve. 11. The control device for a vane type variable valve timing adjusting mechanism according to claim 10, further comprising second control means for controlling and controlling a hydraulic pressure for driving each drain switching valve. A shaft for driving the first hydraulic control valve and the second hydraulic control valve is integrated,
The control means controls the hydraulic control valve according to a deviation between an actual displacement angle of the VCT and a target displacement angle by controlling a current of the hydraulic control valve, and controls the second hydraulic control valve. 11. The control device for a vane type variable valve timing adjusting mechanism according to claim 10, wherein the control device controls the hydraulic pressure for driving each drain switching valve. A first check valve that is provided in a hydraulic pressure supply oil passage of the advance chamber in at least one vane storage chamber and that prevents backflow of hydraulic oil from the advance chamber, and bypasses the first check valve. A second check valve provided in a first drain oil passage, a hydraulic supply oil passage in a retard chamber of at least one vane storage chamber, and preventing backflow of hydraulic oil from the retard chamber; A second drain oil passage that bypasses the two check valves,
The hydraulic control valve is integrated with a drain oil passage control function for opening / closing the first drain oil passage and the second drain oil passage,
When the control means controls the hydraulic control valve to advance the VCT, the control chamber closes the drain oil passage on the advance chamber side into which the hydraulic oil flows and delays the hydraulic chamber to discharge the hydraulic oil. When the VCT is operated to be retarded by closing the drain oil passage on the side of the advance chamber, the drain oil passage on the side of the retard chamber that allows the hydraulic oil to flow in is closed and the hydraulic oil is discharged. The control device for a vane type variable valve timing adjustment mechanism according to any one of claims 1 to 8, wherein the drain oil passage is controlled to open. A first drain switching valve provided in the first drain oil passage and driven by hydraulic pressure; and a second drain switching valve provided in the second drain oil passage and driven by hydraulic pressure;
The first drain oil passage is opened / closed by opening / closing the first drain switching valve by hydraulic control by the drain oil passage control function of the hydraulic control valve, and the second drain is opened. 14. The control device for a vane type variable valve timing adjusting mechanism according to claim 13, wherein the second drain oil passage is opened / closed by opening / closing a switching valve.

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