JP2010127173A - Valve timing control device and valve timing control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve timing control device highly accurately controlling difference in rotational phase of a camshaft with respect to a crankshaft, by highly accurately controlling control current carried to an electromagnetic solenoid. <P>SOLUTION: The valve timing control device includes: a request value calculation means calculating a request value (request current value IAin) of the control current carried to the electromagnetic solenoid based on an operational status of an internal combustion engine; a battery voltage detection means detecting voltage of a battery feeding power to the electromagnetic solenoid; and command value calculation means (B10, B11, B20, B30, B40) correcting the request current value IAin according to a battery voltage detection value (battery voltage VB) to calculate a command value of the control current (the request current IBin after the correction). The command value calculation means variably sets a correction amount with respect to the request current value IAin according to the operational statuses of current consumers (an exhaust-side solenoid and an intake-side solenoid) using the battery as a power feeding source. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  TECHNICAL FIELD The present invention relates to a valve timing adjustment mechanism that adjusts the opening / closing timing of an intake valve or an exhaust valve of an internal combustion engine, and a hydraulic actuator that varies a rotational phase difference of a camshaft with respect to a crankshaft and an oil that controls a flow of hydraulic oil supplied to the hydraulic actuator A configuration that includes a control valve (hereinafter referred to as “OCV”) and an electromagnetic solenoid that controls the operation of the OCV is well known (see, for example, Patent Document 1).

An example of the configuration of the hydraulic actuator will be described. The hydraulic actuator includes a housing connected to one of the crankshaft and the camshaft, and a vane rotor that is connected to the other and accommodated in the housing, and is formed by partitioning the housing by the vane rotor. The hydraulic oil supply amount to the retard chamber and the advance chamber is controlled by OCV. Thereby, the relative rotational position of the vane rotor with respect to the housing can be controlled to the target position, and the rotational phase difference of the camshaft with respect to the crankshaft can be adjusted.
Japanese Patent Application Laid-Open No. 07-229410

  Here, when the hydraulic actuator is driven, the control current actually supplied to the electromagnetic solenoid is slightly deviated from a desired value (required value). The rotational position is greatly deviated. As a result, the rotational phase difference of the camshaft with respect to the crankshaft deviates greatly from the desired position. Therefore, it has been conventionally required to control the control current flowing to the electromagnetic solenoid with high accuracy.

  The present invention has been made to solve the above-mentioned problems, and its purpose is to control the rotational phase difference of the camshaft with respect to the crankshaft with high accuracy by controlling the control current flowing to the electromagnetic solenoid with high accuracy. An object of the present invention is to provide a valve timing control device which can be used.

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

  In the first aspect of the present invention, a required value calculating means for calculating a required value of a control current to be supplied to the electromagnetic solenoid based on an operating state of the internal combustion engine, a battery voltage detecting means for detecting a voltage of a battery to be fed to the electromagnetic solenoid, Command value calculation means for correcting the request value calculated by the request value calculation means in accordance with the battery voltage detection value detected by the battery voltage detection means and calculating the command value of the control current. And the said command value calculation means variably sets the correction amount with respect to the said required value according to the operating state of the electric load which uses a battery as a power supply.

  In response to the above-mentioned requirement that “the control current flowing to the electromagnetic solenoid is controlled with high accuracy”, the present inventor has found that the actual value of the control current deviates from the required value due to the influence of the voltage fluctuation of the battery that supplies power to the electromagnetic solenoid. Considered not to. That is, according to the battery voltage detection value detected by the battery voltage detection means, the request value calculated by the request value calculation means is corrected to calculate the command value of the control current (command value calculation means).

  However, the actual voltage applied to the electromagnetic solenoid deviates from the battery voltage detection value due to a voltage drop or the like generated in the power supply path to the electromagnetic solenoid. In addition, the magnitude of the voltage deviation varies depending on the operating state of the electric load that uses the battery as a power supply. Therefore, it has been found that the control current that actually flows deviates from the required value only by performing the correction described above.

  Therefore, in the present invention, in addition to correcting the required value according to the detected battery voltage value, the correction amount for the required value is variably set according to the operating state of the electric load that uses the battery as the power supply. For this reason, the correction amount can be variably set according to whether or not the above-described voltage deviation occurs, so that it is possible to prevent the control current that actually flows from deviating from the required value. Therefore, the control current flowing to the electromagnetic solenoid can be controlled with high accuracy, and consequently, the rotational phase difference of the camshaft with respect to the crankshaft can be controlled with high accuracy.

  According to a second aspect of the present invention, the command value calculating means calculates a voltage drop amount generated in a power supply path from the battery to the electromagnetic solenoid based on an operating state of the electric load, and the calculated voltage drop. And a means for calculating the correction amount based on the amount and the battery voltage detection value.

  It is assumed that the voltage shift described above is caused by a voltage drop in the power supply path when the electric load is activated. Therefore, according to the present invention, comprising: means for calculating the voltage drop amount based on the operating state of the electric load; and means for calculating the correction amount based on the voltage drop amount and the battery voltage detection value. Thus, it is possible to variably set the correction amount for the command value with a simple control program.

  According to a third aspect of the present invention, when the electric load is supplied by the same system as the power supply path from the battery to the electromagnetic solenoid, a voltage shift due to the voltage drop appears remarkably. Therefore, if the invention according to claim 1 is applied in such a case, the above-described effect of “the control current that actually flows can be prevented from deviating from the required value” is preferably exhibited.

  According to a fourth aspect of the present invention, when the valve timing adjusting mechanism adjusts the opening / closing timing of one of the intake valve and the exhaust valve, the other opening / closing timing of the intake valve and the exhaust valve is adjusted. The command value calculation means performs the variable setting by using an electromagnetic solenoid provided in a valve timing adjustment mechanism that performs the electrical load.

  For example, when the command value is calculated by correcting the required value related to the intake valve timing adjustment mechanism, the correction amount can be varied according to the energization state of the electromagnetic solenoid (electric load) related to the exhaust valve timing adjustment mechanism. Depending on the energization state of the electromagnetic solenoid (electric load) related to the intake valve timing adjustment mechanism, the command value may be calculated by correcting the required value related to the exhaust valve timing adjustment mechanism. The correction amount may be variably set.

  In addition to the invention described in claim 4, specific examples of the electric load include an O2 sensor for detecting an oxygen concentration, a heater mounted on an A / F sensor, and the like. Further, when the command value is calculated by correcting the required value related to the valve timing adjustment mechanism for intake, the correction amount may be variably set with the electromagnetic solenoid as the electric load.

  In the invention according to claim 5 subordinate to claim 4, the variable timing adjustment amount for the correction amount is applied to both the valve timing adjustment mechanism for the intake valve and the valve timing adjustment mechanism for the exhaust valve. In calculating according to the energization amount to the electric load, a hysteresis is provided.

  Here, when the valve timing control device is applied to both the valve timing adjusting mechanism for the intake valve and the valve timing adjusting mechanism for the exhaust valve, the variable set amount with respect to the correction amount is set as the energization amount to the electric load. When trying to calculate accordingly, there are concerns about the following points. That is, the command value for the intake-side electromagnetic solenoid is calculated according to the operating state of the exhaust-side electromagnetic solenoid (electric load), and the command value for the exhaust-side electromagnetic solenoid is calculated from the intake-side electromagnetic solenoid (electric load). Since the calculation is performed according to the operating state, there is a concern that the operations of the electromagnetic solenoids interfere with each other and both command values vibrate.

  In response to this concern, according to the invention described in claim 5, since the hysteresis is provided in calculating the variable set amount with respect to the correction amount according to the energization amount to the electric load, both the command values are set as described above. You can eliminate concerns about vibration.

  The invention described in claim 6 is a valve timing control system comprising the valve timing control device and the valve timing adjusting mechanism. According to this valve timing control system, the above-described various effects can be similarly exhibited.

(First embodiment)
Hereinafter, a first embodiment in which a valve timing control device and a valve timing control system according to the present invention are applied to an in-vehicle gasoline engine (internal combustion engine) will be described with reference to the drawings.

  FIG. 1 shows the overall configuration of the valve timing control system according to the present embodiment.

  As illustrated, the power of the crankshaft 10 is transmitted to the camshaft 14 via the belt 12 and the VCT 20. The VCT 20 includes a first rotating body 21 mechanically connected to the crankshaft 10 and a second rotating body 22 mechanically connected to the camshaft 14. In the present embodiment, the second rotating body 22 includes a plurality of protrusions 22 a, and the second rotating body 22 is accommodated in the first rotating body 21. Then, the retard angle for retarding the relative rotation angle (rotational phase difference) of the camshaft 14 with respect to the crankshaft 10 by the protrusion 22a of the second rotating body 22 and the inner wall of the first rotating body 21. A chamber 23 and an advance chamber 24 for advancing the rotational phase difference are partitioned. The VCT 20 further includes a lock mechanism 25 that fixes the first rotating body 21 and the second rotating body 22 at a rotational phase difference (maximum retard angle position) at which the volume of the retard chamber 23 is maximized. I have.

  The VCT 20 is a hydraulic actuator that is hydraulically driven by hydraulic fluid flowing in and out between the retard chamber 23 and the advance chamber 24. The flow of the hydraulic oil is controlled by an oil control valve (OCV30).

  The OCV 30 supplies hydraulic oil from a hydraulic pump (not shown) to the retard chamber 23 or the advance chamber 24 via the supply path 31 and the retard path 32 or the advance path 33. Further, the OCV 30 causes hydraulic oil to flow out from the retard chamber 23 or the advance chamber 24 to an oil pan (not shown) via the retard path 32 or the advance path 33 and the discharge path 34. The flow path area between the retard path 32 or the advance path 33 and the supply path 31 or the discharge path 34 is adjusted by the spool 35. That is, the spool 35 is pushed to the left side in the drawing by the spring 36 and a force toward the right side in the drawing is applied by the electromagnetic solenoid 37. For this reason, by applying a control signal to the electromagnetic solenoid 37 and adjusting the duty of this control signal, the control current flowing through the electromagnetic solenoid 37 can be adjusted and the displacement amount of the spool 35 can be manipulated. It becomes possible.

  For example, when the force by which the spring 36 pushes the spool in the left direction in the figure is larger than the force by which the magnetic field of the electromagnetic solenoid 37 displaces the spool 35 in the reverse direction, the spool 35 is displaced in the left direction in the figure. When the spool 35 is displaced to the left from the illustrated position, hydraulic oil is supplied from the hydraulic pump to the retard chamber 23 via the supply path 31 and the retard path 32, and from the advance chamber 24 to the advance path. The hydraulic oil is discharged to the oil pan through 33 and the discharge path 34. Thereby, the 2nd rotary body 22 rotates in the clockwise reverse direction in the figure.

  On the other hand, when the force by which the magnetic field of the electromagnetic solenoid 37 displaces the spool 35 in the right direction in the figure is larger than the force by which the spring 36 pushes the spool 35 in the left direction in the figure, the spool 35 is displaced in the right direction in the figure. When the spool 35 is displaced to the right from the illustrated position, the hydraulic oil is supplied from the hydraulic pump to the advance chamber 24 via the supply path 31 and the advance path 33, and from the retard chamber 23 to the retard path. The hydraulic oil is discharged to the oil pan through 32 and the discharge path 34. Thereby, the 2nd rotary body 22 rotates clockwise in the figure.

  However, as shown in the figure, when the spool 35 is in a position closing the retard path 32 and the advance path 33, the flow of hydraulic oil between the retard chamber 23 and the advance chamber 24 is stopped and the rotation is performed. The phase difference is maintained.

  An electronic control unit (ECU 40) that adjusts the duty of a control signal applied to the electromagnetic solenoid 37 is mainly composed of a microcomputer (microcomputer 41). The detection value of the crank angle sensor 42 that detects the rotation angle of the crankshaft 10, the detection value of the cam angle sensor 44 that detects the rotation angle of the camshaft 14, the detection value of the airflow meter 46 that detects the intake air amount, etc. Then, the detected values of various operating states of the internal combustion engine are taken in, various calculations are performed based on the detected values, and the operation of various actuators of the internal combustion engine such as the OCV 30 is controlled based on the calculation results.

  The VCT 20, OCV 30, and electromagnetic solenoid 37 constitute a valve timing adjusting mechanism. As described above, the ECU 40 adjusts the duty of the control signal to be applied to the electromagnetic solenoid 37, whereby the rotational phase difference of the VCT 20 is adjusted. The rotational phase difference of the cam shaft 14 with respect to the shaft 10 is adjusted. As a result, the opening / closing timing of the exhaust valve or the intake valve of the internal combustion engine is adjusted. In this embodiment, the valve timing adjusting mechanism having the above-described configuration is mounted on both the camshaft 14 that drives the intake valve and the camshaft 14 that drives the exhaust valve.

  Next, a power supply path for supplying power from the battery 50 mounted on the vehicle to the electromagnetic solenoid 37 will be described with reference to FIG.

  An input terminal RI of the main relay 51 is connected to the battery 50, and a first wire harness 52 and a second wire harness 53 are connected to the output terminal RO of the main relay 51. The first wire harness 52 and the second wire harness 53 are connected to input terminals of various electric loads R mounted on the vehicle. In particular, the second wire harness 53 is connected to the power supply terminal EI of the ECU 40. Yes. The energization of each electric load R can be controlled by the ECU 40. Hereinafter, the power feeding path formed by the first wire harness 52 is referred to as a first power feeding path L1, and the power feeding path formed by the second wire harness 53 is referred to as a second power feeding path L2.

  Specific examples of the electric load R include an electric heater mounted on a gas sensor such as an A / F sensor, an O2 sensor, and a NOx sensor, an electric motor, and an electromagnetic solenoid. The electromagnetic solenoid 37 of the intake valve VCT 20 as the electric load R and the electromagnetic solenoid 37 of the exhaust valve VCT 20 are connected to the first wire harness 52. That is, both the electromagnetic solenoids 37 on the intake side and the exhaust side are arranged in the same power supply path L1 and are configured to be supplied with power in the same system.

  The ECU 40 includes a battery voltage detection circuit 40a that detects an output voltage (battery voltage VB) of the battery 50. In the present embodiment, the voltage at the input terminal RI of the main relay 51 is detected as the battery voltage VB. The battery voltage detection circuit 40a corresponds to “battery voltage detection means”.

  Hereinafter, when the microcomputer 41 of the ECU 40 calculates the control signal (duty signal) output to the electromagnetic solenoid 37, the calculation method will be described.

  The control signal is calculated so as to feedback control the rotational phase difference of the VCT 20. First, this feedback control will be described in detail. The microcomputer 41 calculates an actual advance amount that is an actual rotation angle difference of the camshaft 14 with respect to the crankshaft 10 based on the detection value of the crank angle sensor 42 and the detection value of the cam angle sensor 44. Further, based on the engine speed calculated based on the detected value of the crank angle sensor 42 and the parameters (intake air amount, etc.) indicating the engine load detected by the air flow meter 46, the target of the rotational phase difference of the VCT 20 is obtained. A value (target advance amount) is calculated. This target advance amount is adapted to an optimum value for improving the combustion state of the internal combustion engine. At the time of starting the internal combustion engine, the rotational phase difference on the intake side is fixed at the most retarded position and the rotational phase difference on the exhaust side is the most advanced until the discharge pressure of the hydraulic pump necessary to start driving the VCT 20 is reached. It is desirable to fix the corner position.

  Then, the operation amount of the VCT 20 is calculated based on the calculated actual advance amount and target advance amount. Specifically, the feedback manipulated variable is calculated by proportional differential control based on the deviation between the actual advance amount and the target advance amount. Then, the feedback operation amount is converted into an energization amount to the electromagnetic solenoid 37, a control current value for driving the OCV 30 is calculated, and the control current value is converted into a duty value.

  By adjusting the duty value, the control current flowing through the electromagnetic solenoid 37 is adjusted. Thereby, the hydraulic pressure of the hydraulic fluid supplied to the retard chamber 23 and the advance chamber 24 is adjusted, and the actual advance amount can be feedback-controlled to the target advance amount.

  The control current value (value before being converted into the duty value) calculated by the above feedback control is referred to as a request current value (corresponding to the request value) in the following description. Further, the ECU 40 that calculates the required current value in this way corresponds to “requested value calculating means”.

  Here, even if the duty signal output to the electromagnetic solenoid 37 is the same, if the battery voltage VB is different, the actual amount of control current flowing to the electromagnetic solenoid 37 will be different. Therefore, in the present embodiment, the required current value is not converted into the duty value as it is, but the required current value is corrected according to the battery voltage VB detected by the battery voltage detection circuit 40a, and the corrected required current value (command value) is corrected. Equivalent to the duty value.

  The functional block diagram shown in FIG. 3 explains a method for calculating a control signal to be output to the electromagnetic solenoid 37 of the intake side VCT. The required current value IAin calculated by the feedback control described above is corrected according to the value of the battery voltage VB detected by the battery voltage detection circuit 40a by the correction ratio calculation unit B30 and the correction unit B40 in the figure.

  More specifically, the correction ratio calculation unit B30 (command value calculation means) calculates the ratio of the battery voltage VB1 with respect to the reference voltage (14 volts in the example of FIG. 3) as the correction ratio. However, the battery voltage VB1 used here is a value after being corrected by voltage drop amounts ΔVin and ΔVex described later. Then, the correction unit B40 (command value calculation means) calculates a value obtained by multiplying the correction ratio calculated by the correction ratio calculation unit B30 and the required current value IAin as a value IBin after correction of the required current value IAin. To do. The conversion unit B50 in the figure converts the corrected required current value IBin into a duty value. This duty value signal is output as a control signal to the electromagnetic solenoid 37 of the intake side VCT.

  In addition, since the amount (correction amount) by which the required current value IAin is corrected is determined by the correction ratio calculated by the correction ratio calculation unit B30, the correction ratio calculation unit B30 calculates the correction amount for the required current value IAin. It can be said that. The calculation method of the control signal output to the electromagnetic solenoid 37 of the exhaust side VCT is the same as the calculation method of the control signal on the intake side shown in FIG.

  However, the actual voltage V1 (see FIG. 2) applied to the electromagnetic solenoid 37 deviates from the battery voltage VB detected by the battery voltage detection circuit 40a. This is due to a voltage drop or the like generated in the first power supply path L1. In addition, the magnitude of the voltage deviation depends on the operating state of the electrical load R fed through the same path as the first power feeding path L1 related to the electromagnetic solenoid 37 of the intake side VCT 20 (hereinafter referred to as the intake side solenoid 37). Change. That is, in the example of FIG. 2, the actual applied voltage V1 to the intake side solenoid 37 changes according to the operating state of the electromagnetic solenoid 37 of the exhaust side VCT 20 (hereinafter referred to as the exhaust side solenoid 37). Also, the actual applied voltage V1 to the intake side solenoid 37 varies depending on the operating state of the intake side solenoid 37 itself.

  Therefore, in the present embodiment, the battery voltage VB is corrected by taking into account the voltage drop amount ΔVex caused by the operation of the exhaust side solenoid 37 and the voltage drop amount ΔVin caused by the operation of the intake side solenoid 37, The required current value IAin to the intake side solenoid 37 is corrected based on the corrected battery voltage VB1.

  More specifically, the voltage drop amount calculation unit B10 (command value calculation means) in FIG. 3 calculates the voltage drop amount ΔVex based on the required current value IAex to the exhaust side solenoid 37. For example, the relationship between the required current value IAex and the voltage drop amount ΔVex is acquired in advance by a test, and the acquired data is stored as a conversion table shown in FIG. Then, the voltage drop amount ΔVex is calculated from the required current value IAex using the conversion table of FIG. The voltage drop amount calculation unit B11 (command value calculation means) calculates the voltage drop amount ΔVin based on the required current value IAin to the intake side solenoid 37. Also in this calculation, the conversion table of FIG. 4 may be used in the same manner as the voltage drop amount calculation unit B10. As shown in FIG. 4, hysteresis is provided so that the voltage drop amounts ΔVex and ΔVin change stepwise with different threshold values when the requested current values IAex and IAin rise and fall.

  Then, the voltage correction unit B20 (command value calculation means) subtracts the voltage drop amounts ΔVex and ΔVin calculated by the respective voltage drop amount calculation units B10 and B11 from the battery voltage VB detected by the battery voltage detection circuit 40a, The value obtained by subtraction is used as a corrected battery voltage VB1 for correcting the required current value IAin in the correction unit B40.

  Since the amount of correction of the battery voltage VB is determined by the voltage drop amounts ΔVex and ΔVin calculated by the voltage drop amount calculation units B10 and B11, the voltage drop amount calculation units B10 and B11 are changed by the correction unit B40. It can be said that the correction amount for correcting the required current value IAin is variably set. It can also be said that the variable set amount is calculated.

  FIG. 5 is a flowchart for explaining a processing procedure for calculating the command value (the corrected required current value IBin) by correcting the required current value IAin as described above, and this processing is repeatedly executed by the CPU of the microcomputer 41. The

  First, in step S10, the battery voltage VB detected by the battery voltage detection circuit 40a, the required current IAin to the intake side VCT20 and the required current IAex to the exhaust side VCT20 calculated by the feedback control described above are acquired.

  In subsequent step S11, voltage drop amounts ΔVex and ΔVin are calculated using the conversion table of FIG. 4 based on the required currents IAin and IAex acquired in step S10. In the following step S12, the battery voltage VB acquired in step S10 is corrected using the voltage drop amounts ΔVex and ΔVin. Specifically, a value obtained by subtracting the voltage drop amounts ΔVex and ΔVin from the battery voltage VB is defined as a control voltage VB1 (corrected battery voltage).

  In subsequent step S13, the required current values IAin and IAex are corrected using the control voltage VB1 calculated in step S12. Specifically, the ratio of the control voltage VB1 to the reference voltage (14 volts in the example of FIG. 3) is calculated as a correction ratio, and a value obtained by multiplying the correction ratio and the required current value IAin is corrected. The subsequent required current value IBin is used. In the above description, the procedure for correcting the required current IAin to the intake side VCT 20 has been described. However, the correction for the required current IAex to the exhaust side VCT 20 is also performed in the same procedure.

  Next, the effect by this embodiment explained in full detail above is demonstrated, referring FIG.

  FIG. 6 is a diagram for explaining the effect of correcting the battery voltage VB based on the voltage drop amounts ΔVex and ΔVin. The left column in the figure is the right side when the voltage drop correction according to the present embodiment is not executed. The column shows changes with time of various values shown in (a) to (e) when the voltage drop correction according to the present embodiment is executed.

  As shown in FIG. 6A, the target advance amount of the exhaust side VCT 20 was increased at the time point t1 and then decreased at the time point t2 under the condition that the target advance amount of the intake side VCT 20 was kept constant. One aspect of the case will be described below. As shown in FIG. 6B, the actual advance amount of the exhaust VCT increases with a predetermined response delay from the time point t1 as the target advance amount is increased. Thereafter, the target advance amount is decreased with a predetermined response delay from time t2.

  On the other hand, when the correction of the voltage drop is not executed, the actual advance angle amount of the intake VCT temporarily decreases at the time point t1 although the target advance angle amount is kept constant, and the t2 It temporarily increases at the time (see the left column in FIG. 6B). That is, an unintended operation is performed such that the actual advance angle amount of the intake VCT temporarily varies. This is because the actual voltage V1 applied to the intake-side solenoid 37 changes as the amount of control current flowing to the exhaust-side solenoid 37 changes, and as a result, the required current value IAin is kept constant. Regardless of this, the actual control current flowing to the intake side solenoid 37 has changed. Since the required current value IAin is calculated by the feedback control described above, the required current value IAin and the corrected required current value IBin gradually increase or decrease from time t1 and t2 (FIG. 6C). (See e) Left column). Therefore, the deviation of the actual advance amount with respect to the target advance amount at the time points t1 and t2 is eliminated as time elapses.

  On the other hand, in the case of the present embodiment in which the voltage drop is corrected, it is possible to avoid the actual advance angle amount of the intake VCT from temporarily changing at the time points t1 and t2 (right side of FIG. 6B). Column). This is because the battery voltage VB is corrected so as to decrease by the amount of voltage drop ΔVex when the amount of control current flowing to the exhaust side solenoid 37 increases (time t1). According to this correction, even though the required current value IAin remains constant (see the right column in FIG. 6C), the corrected required current value IBin is corrected by the amount of voltage drop of the battery voltage VB. Increases stepwise at time t1, and decreases stepwise at time t2. According to this, even if the actual voltage V1 applied to the intake side solenoid 37 changes due to the change in the control current amount flowing to the exhaust side solenoid 37, it is corrected so as to correspond to the change in the voltage V1. The required current value IBin changes, and the duty changes. Therefore, it is possible to avoid a change in the control current that actually flows to the intake-side solenoid 37, and it is possible to control the control current that flows to the electromagnetic solenoid 37 with high accuracy.

  In short, unless the voltage drop correction is executed contrary to the present embodiment, the rotational phase difference of the intake VCT 20 temporarily deviates from the target value at the time of transition in which the rotational phase difference of the exhaust VCT 20 is varied. On the other hand, according to the present embodiment in which the voltage drop correction is performed, the rotational phase difference of the intake VCT 20 temporarily deviates from the target value even during a transient time when the rotational phase difference of the exhaust VCT 20 is varied. In addition, an unintended operation of the intake VCT 20 can be avoided, and the rotational phase difference of the cam shaft 14 with respect to the crank shaft 10 can be controlled with high accuracy.

  In addition, according to the present embodiment, when the voltage drop amounts ΔVex and ΔVin are calculated from the required current values IAex and IAin using the conversion table shown in FIG. 4, the conversion table in FIG. 4 has hysteresis. Therefore, the required current value IAin to the intake side solenoid 37 is corrected based on the required current value IAex to the exhaust side solenoid 37, and the required current value IAex to the exhaust side solenoid 37 is corrected to the required current value IAin to the intake side solenoid 37. When correcting based on the above, it is possible to suppress the vibration of both required current values IAin and IAex.

(Second Embodiment)
In the first embodiment, the intake-side solenoid 37 and the exhaust-side solenoid 37 are arranged to be fed with the same path. Therefore, the required current value IAin to the intake side solenoid 37 is corrected based on the operating state of the exhaust side solenoid 37 as the electric load R, and the required current value IAex to the exhaust side solenoid 37 is corrected to the intake air as the electric load R. Correction is performed based on the operating state of the side solenoid 37.

  On the other hand, in the present embodiment, it is assumed that the intake side solenoid 37 and the electric heater (electric load R) mounted on the gas sensor are arranged to be fed by the same path. Therefore, the required current value IAin to the intake side solenoid 37 is corrected based on the operating state of the heater as the electric load R. Specifically, the voltage drop amount is calculated according to the energization amount to the heater, and the control voltage VB1 (corrected battery voltage) is calculated by subtracting the battery voltage VB by the calculated voltage drop amount. The required current value IAin is corrected based on the calculated control voltage VB1.

  FIG. 7 is a flowchart illustrating a processing procedure for calculating the command value (corrected required current value IBin) by correcting the required current value IAin as described above. This processing is repeatedly executed by the CPU of the microcomputer 41. The

  First, in step S20, the battery voltage VB detected by the battery voltage detection circuit 40a and the applied voltage Vh to the heater are acquired. In subsequent step S21, a voltage drop amount ΔVh is calculated based on the heater applied voltage Vh acquired in step S20. In the subsequent step S22, the battery voltage VB acquired in step S20 is corrected using the voltage drop amount ΔVh. Specifically, a value obtained by subtracting the voltage drop amount ΔVh from the battery voltage VB is set as a control voltage VB1 (corrected battery voltage).

  In the subsequent step S23, the required current value IAin is corrected using the control voltage VB1 calculated in step S22. Specifically, the ratio of the control voltage VB1 to the reference voltage is calculated as a correction ratio, and a value obtained by multiplying the correction ratio and the required current value IAin is set as a corrected required current value IBin.

  In the above description, the procedure for correcting the required current IAin to the intake-side VCT 20 has been described. However, when the exhaust-side solenoid 37 and the electric heater are arranged to be fed by the same path, the exhaust-side VCT 20 is corrected. The correction of the required current IAex is performed in the same procedure.

  If the voltage drop correction according to the present embodiment described in detail above is not executed, the rotational phase difference of the intake VCT 20 temporarily deviates from the target value at the time of transition in which the energization amount to the electric heater is varied. On the other hand, according to the present embodiment in which the voltage drop correction is performed, the rotational phase difference of the intake VCT 20 temporarily deviates from the target value even during a transient time in which the amount of current supplied to the electric heater is varied. Unintentional operation of the intake VCT 20 can be avoided.

(Other embodiments)
The present invention is not limited to the description of the above embodiment, and may be modified as follows. Moreover, you may make it combine the characteristic structure of each embodiment arbitrarily, respectively.

  In the first embodiment, in correcting the required current IAin to the intake side VCT 20, in addition to the exhaust side solenoid 37, its own electromagnetic solenoid (intake side solenoid 37) is also used as the electric load R to correct the battery voltage VB. Both of the required current values IAin and IAex are used. On the other hand, the use of the required current IAin for its own electromagnetic solenoid for the correction of the battery voltage VB may be abolished, and only the required current IAex for the exhaust side solenoid 37 may be used for the correction of the battery voltage VB. .

  When the first and second embodiments are combined, for example, when the intake side solenoid 37, the exhaust side solenoid 37, and the electric heater are arranged to be fed by the same path, both required current values IAin, It is desirable to correct the battery voltage VB based on IAex and the energization amount to the heater.

The figure which shows the whole structure of the valve timing control system concerning 1st Embodiment of this invention. The figure which shows the electric power feeding path | route which supplies electric power from a battery to the electromagnetic solenoid of FIG. The functional block diagram explaining the calculation method of the control signal output to the electromagnetic solenoid of FIG. The figure which shows the conversion table used with the voltage drop amount calculation part of FIG. The flowchart which shows the procedure which correct | amends a battery voltage by the method of FIG. The figure explaining the effect by having corrected the battery voltage by the method of FIG. The flowchart which shows the procedure which correct | amends a battery voltage in 2nd Embodiment of this invention.

Explanation of symbols

20 ... VCT (hydraulic actuator), 30 ... OCV (control valve), 37 ... electromagnetic solenoid, 40 ... ECU (required value calculation means), 40a ... battery voltage detection circuit (battery voltage detection means), B10, B11 ... voltage drop A quantity calculation unit (command value calculation unit), B20... Voltage correction unit (command value calculation unit), B30... Correction ratio calculation unit (command value calculation unit), B40.

Claims (6)

A hydraulic actuator that varies a rotational phase difference of a camshaft with respect to a crankshaft to adjust an opening / closing timing of an intake valve or an exhaust valve of an internal combustion engine, a control valve that controls a flow of hydraulic oil supplied to the hydraulic actuator, Applied to a valve timing adjustment mechanism configured with an electromagnetic solenoid that controls the operation of the control valve,
A required value calculating means for calculating a required value of a control current flowing to the electromagnetic solenoid based on an operating state of the internal combustion engine;
Battery voltage detection means for detecting the voltage of the battery that supplies power to the electromagnetic solenoid;
Command value calculation means for correcting the request value calculated by the request value calculation means and calculating the command value of the control current according to the battery voltage detection value detected by the battery voltage detection means;
With
The valve value control device, wherein the command value calculation means variably sets a correction amount for the required value in accordance with an operating state of an electric load using the battery as a power supply. The command value calculation means includes
Means for calculating a voltage drop amount generated in a power supply path from the battery to the electromagnetic solenoid based on an operating state of the electric load;
Means for calculating the correction amount based on the calculated voltage drop amount and the battery voltage detection value;
The valve timing control device according to claim 1, comprising:   3. The valve timing control device according to claim 1, wherein the electric load is supplied in the same system as a power supply path from the battery to the electromagnetic solenoid. 4. In the case where the valve timing adjustment mechanism is for adjusting the opening / closing timing of one of the intake valve and the exhaust valve,
The command value calculation means performs variable setting of the correction amount, with an electromagnetic solenoid provided in a valve timing adjustment mechanism for adjusting the opening / closing timing of the other of the intake valve and the exhaust valve as the electric load. The valve timing control device according to any one of claims 1 to 3. Applied to both the valve timing adjustment mechanism for the intake valve and the valve timing adjustment mechanism for the exhaust valve;
5. The valve timing control device according to claim 4, wherein a hysteresis is provided in calculating the variable set amount with respect to the correction amount according to the energization amount to the electric load.   A valve timing control system comprising: the valve timing control device according to any one of claims 1 to 5; and the valve timing adjustment mechanism.

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