JPH10220257A - Valve timing controller for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a required acceleration feeling by the suitable control amount according to the operation state of an internal combustion engine. SOLUTION: The feedback correction duty DVFB to be feedback-collected on the basis of the relative rotation angle AC and the target relative rotation angle TAC is calculated (a step S104). The smoothed target relative rotation angle TACSM obtained by smoothing the target relative rotation angle TAC is subtracted from the target relative rotation angle TAC, the target relative rotation angle deviation DELTAC is calculated (a step S106), and the transient correction duty DVTC is calculated (a step S107). The feedback correction duty DVFB in the transient time is suitably corrected (a step S108) by using the transient correction duty DVTC calculated according to the target relative rotation angle TAC. Therefore, control responsiveness of a valve timing control mechanism 50 is improved, and control stability in the steady time can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing control apparatus for an internal combustion engine which can change at least one of an intake valve and an exhaust valve of an internal combustion engine in accordance with an operation state.

[0002]

2. Description of the Related Art Conventionally, as a mechanism for variably controlling the opening / closing timing of an intake valve or an exhaust valve in accordance with the operation state of an internal combustion engine, the rotation phase of a camshaft with respect to a cam pulley rotating in synchronization with a crankshaft is changed. As a prior art document related to the valve timing control device for an internal combustion engine described above, one disclosed in Japanese Patent Application Laid-Open No. 7-247869 is known.

In this technology, a rapid acceleration or a gentle acceleration is detected in accordance with a change in throttle opening due to depression of an accelerator pedal, and a control map is switched to change the valve timing to obtain a feeling of acceleration. It is shown.

[0004]

By the way, in the above-mentioned apparatus, a plurality of control maps need to be stored in advance in order to switch the control map by detecting the rapid acceleration or the slow acceleration. Further, the parameters of the control map that can be switched by detecting the rapid acceleration or the slow acceleration are different, and there is a problem that it is difficult to adjust the control amount for changing the valve timing to the actual operation state of the internal combustion engine.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a valve timing control apparatus for an internal combustion engine capable of obtaining a desired feeling of acceleration by an appropriate control amount according to the operating state of the internal combustion engine. Provision is an issue.

[0006]

According to the first aspect of the present invention, there is provided a valve timing control apparatus for an internal combustion engine. The transient correction rotation angle in the transient state is calculated by the transient correction rotation angle calculating means in accordance with the target relative rotation angle with respect to the rotation angle of the shaft. The control rotation angle calculated by the relative rotation angle control means is corrected by the control rotation angle correction means based on the transient correction rotation angle. As described above, the control rotation angle during the transition is appropriately corrected using the transient correction rotation angle calculated according to the magnitude of the target relative rotation angle, so that the control responsiveness of the valve timing control mechanism can be improved. .

In the valve timing control device for an internal combustion engine according to the present invention, the target relative rotation angle is calculated using the target relative rotation angle calculated according to the operating state of the internal combustion engine and the smoothed target relative rotation angle. The transient correction rotation angle based on the target relative rotation angle deviation is small between the start and the convergence of the transition, and is increased during the transition. For this reason, the control response of the valve timing control mechanism in the transient state is improved, and the control stability in the steady state can be ensured.

According to the third aspect of the present invention, the transient correction rotation angle is calculated based on the amount of change in the target relative rotation angle calculated according to the operation state of the internal combustion engine. Accordingly, appropriate correction is performed depending on whether the degree of the transition is gradual or steep, so that the control responsiveness of the valve timing control mechanism can be improved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples.

FIG. 1 is a schematic configuration diagram showing a double overhead cam type internal combustion engine to which an internal combustion engine valve timing control apparatus according to an embodiment of the present invention is applied, and peripheral devices thereof.

In FIG. 1, reference numeral 10 denotes an internal combustion engine, and a pair of chain sprockets 1 is driven via a chain 12 from a crankshaft 11 as a drive shaft of the internal combustion engine 10.
Driving force is transmitted to 3,14. A pair of camshafts 1 as driven shafts are provided on a pair of chain sprockets 13 and 14 which are rotated in synchronization with the crankshaft 11.
5 and 16 are provided, and these camshafts 15 and 16 are provided.
The intake valve and the exhaust valve (not shown) are driven to open and close.

The crankshaft 11 is provided with a crank position sensor 21, and the camshaft 15 is provided with a cam position sensor 22. The pulse signal θ1 output from the crank position sensor 21 and the pulse signal θ output from the cam position sensor 22
2 is ECU (Electronic Control Unit)
30 is input.

The ECU 30 is configured as a CPU as a well-known central processing unit, a ROM storing a control program, a RAM storing various data, an input / output circuit, and a logical operation circuit including a bus line connecting them. ing.

In addition to these signals, the ECU 30 provides various information such as an engine speed Ne indicating the operating state of the internal combustion engine 10, an intake air amount (intake air amount) GN per unit engine speed, a cooling water temperature, a throttle opening and the like. The signal is input, and a relative rotation angle AC and a target relative rotation angle TAC of the camshaft 15 with respect to the crankshaft 11 described later are calculated. The spool valve 4 is driven by a drive signal from the ECU 30.
The duty ratio of the linear solenoid 41 is controlled, and the oil in the oil tank 45 is supplied to the one camshaft 15 through the supply oil passage 47 by the pump 46 (the hatched line in FIG. 1). Part). By adjusting the amount of oil supplied to the valve timing control mechanism 50, the camshaft 15 is rotatable with a predetermined phase difference with respect to the chain sprocket 13, that is, the crankshaft 11, and the camshaft 15 is rotatable. The shaft 15 can be set to the target relative rotation angle TAC. The oil from the valve timing control mechanism 50 is returned to the oil tank 45 through the drain oil passage 48.

Here, when the crankshaft 11 makes one rotation and the number of pulses from the crank position sensor 21 is generated N, the number of pulses from the cam position sensor 22 is generated by one rotation of the camshaft 15. To If the maximum value of the timing conversion angle of the camshaft 15 is θmax ° CA (crank angle), N <(360
/ Θmax). As a result, when calculating the relative rotation angle AC, the pulse signal θ1 of the crank position sensor 21 and the pulse signal θ2 of the cam position sensor 22 generated following the pulse signal θ1 can be used.

Next, referring to FIGS. 3 and 4 based on a flowchart of FIG. 2 showing a processing procedure of the ECU 30 used in the valve timing control device for an internal combustion engine according to one embodiment of the present invention. I will explain. Note that the flowchart of FIG. 2 is repeatedly executed at predetermined time intervals.
FIG. 3 is a map for obtaining a target relative rotation angle TAC from the engine speed Ne and the intake air amount GN, and FIG. 4 is a map showing a target relative rotation angle TAC and a smoothed value obtained by smoothing the target relative rotation angle TAC. It is a time chart which shows the transition state with smoothing target relative rotation angle TACSM.

In FIG. 2, first, in step S101,
The crank position sensor 2 is used as various sensor signals.
1, the output signal .theta.2 of the cam position sensor 22 and the engine speed N representing the operating state of the internal combustion engine 10.
e and the intake air amount GN are read. Next, step S10
2 and the output of the crank position sensor 21 and the output signal .theta.2 of the cam position sensor 22 read in step S101.
, The relative rotation angle AC (= θ1−θ2) which is the current phase difference of the camshaft 15 is calculated.

Next, the process proceeds to step S103, in which the engine speed Ne and the intake air amount GN read in step S101 are read.
The target relative rotation angle TAC, which is the current target phase difference, is calculated from the map shown in FIG. Next, step S
In step 104, the feedback correction duty DVFB as a control rotation angle that is feedback-corrected based on the relative rotation angle AC calculated in step S102 and the target relative rotation angle TAC calculated in step S103 is expressed by the following equation (1). Is calculated by Here, K1 is a correction gain.

[0019]

DVFB = (TAC−AC) * K1 (1) Next, the process proceeds to step S105, where the target relative rotation angle TA is set.
Current smoothed target relative rotation angle TACSM obtained by smoothing C
i is calculated by the following equation (2). Where TACSM
i-1 is the previous smoothing target relative rotation angle, and K2 is the smoothing gain.

[0020]

TACSMi = TACSMi-1 * (1-K2) + TAC * K2 (2) Next, the process proceeds to step S106, where the target relative rotation angle TAC calculated in step S103 and the target relative rotation angle TAC are calculated in step S105. The target relative rotation angle deviation DELTAC is calculated by the following equation (3) based on the tempered target relative rotation angle TACSMi (see FIG. 4).

[0021]

DELTAC = TAC−TACSMi (3) Next, the process proceeds to step S107, where the transient correction duty DVTC as the transient correction rotation angle is calculated based on the target relative rotation angle deviation DELTAC calculated in step S106. It is calculated by equation (4). Here, K3 is a correction gain.

[0022]

DVTC = DELTAC * K3 (4) Next, the process proceeds to step S108, where the feedback correction duty DVFB calculated in step S104 is the transient correction duty DVT calculated in step S107.
The control Duty (duty ratio) DV corrected based on C and output to the linear solenoid 41 is calculated by the following equation (5), and this routine ends.

[0023]

DV = DVFB + DVTC (5) As described above, the valve timing control device for an internal combustion engine according to the present embodiment serves as a driven shaft that opens and closes an intake valve from a crankshaft 11 serving as a drive shaft of the internal combustion engine 10. A valve timing control mechanism 5 that is provided in a driving force transmission system including a chain 12 and the like that transmits driving force to the camshaft 15 and that can relatively rotate the camshaft 15 within a predetermined angle range.
0, a crank position sensor 21 as a drive shaft rotation angle detecting means for detecting the rotation angle θ1 of the crankshaft 11, and a cam position sensor 22 as a driven shaft rotation angle detecting means for detecting the rotation angle θ2 of the camshaft 15.
And the rotation angle θ1 of the crankshaft 11 detected by the crank position sensor 21 and the cam position sensor 2
A relative rotation angle calculation means achieved by the ECU 30 for calculating a relative rotation angle AC which is a phase difference between the rotation angle θ2 of the camshaft 15 and the crankshaft 11 according to the operating state of the internal combustion engine 10. Target relative rotation angle calculation means achieved by the ECU 30 which calculates a target relative rotation angle TAC which is a target phase difference between the rotation angle θ1 of the camshaft 15 and the rotation angle θ2 of the camshaft 15; A feedback correction duty DVFB to be subjected to feedback correction is calculated in accordance with a deviation between the calculated relative rotation angle AC and the target relative rotation angle TAC calculated by the target relative rotation angle calculation means. Relative rotation angle control means achieved by the ECU 30 which relatively rotates the motor 15 and an eye calculated by the target relative rotation angle calculation means. E for calculating the transient correction duty DVTC during transient corresponding to the relative angle of rotation TAC
The ECU 30 corrects the feedback correction duty DVFB calculated by the relative rotation angle control means based on the transient correction rotation angle calculation means achieved by the CU 30 and the transient correction duty DVTC calculated by the transient correction rotation angle calculation means. Control rotation angle correction means achieved by the above.

Accordingly, the target relative rotation angle between the rotation angle θ1 of the crankshaft 11 and the rotation angle θ2 of the camshaft 15 calculated according to the operating state of the internal combustion engine 10 by the ECU 30 that achieves the target relative rotation angle calculation means. The transient correction duty DVTC at the time of transition is calculated by the ECU 30 that achieves the transient correction rotation angle calculation means corresponding to TAC. Based on the transient correction duty DVTC, the feedback correction duty DVFB calculated by the ECU 30 that achieves the relative rotation angle control means is corrected by the ECU 30 that achieves the control rotation angle correction means. in this way,
Using the transient correction duty DVTC calculated according to the magnitude of the target relative rotation angle TAC, the feedback correction duty DVFB during the transition is appropriately corrected, so that the control responsiveness of the valve timing control mechanism 50 is improved.

In the valve timing control apparatus for an internal combustion engine according to the present embodiment, the transient correction rotation angle calculating means achieved by the ECU 30 smoothes the target relative rotation angle TAC and the target relative rotation angle TAC. The transient correction duty DVTC is calculated according to a target relative rotation angle deviation DELTAC which is a deviation from the rotation angle TACSM. That is, the ECU 30 that achieves the transient correction rotation angle calculation means
The transient corresponding to the magnitude of the target relative rotation angle deviation DELTAC obtained by subtracting the smoothed target relative rotation angle TAC from the target relative rotation angle TAC with a predetermined smoothing gain. The transient correction duty DVTC at the time is calculated. Therefore,
The target relative rotation angle TAC calculated according to the operation state of the internal combustion engine and the smoothed target relative rotation angle TA obtained by smoothing the target relative rotation angle TAC
Target relative rotation angle deviation DEL calculated using CSM
The transient correction duty DVTC based on TAC is small at the start of the transition and at the time of convergence, and is increased during the transition.
Therefore, the valve timing control mechanism 5 at the time of transition is
The control responsiveness of 0 is improved, and the control stability in a steady state can be ensured.

In the above-described embodiment, the ECU 30 that achieves the transient correction rotation angle calculation means uses the target relative rotation angle T
Using the smoothed target relative rotation angle TACSM obtained by smoothing the AC with a predetermined smoothing gain, the transient correction duty DVTC is calculated according to the target relative rotation angle deviation DELTAC which is a deviation from the target relative rotation angle TAC. However, when the present invention is implemented, the present invention is not limited to this. In addition, the amount of change in the target relative rotation angle TAC calculated by the map shown in FIG. May be used to calculate the transient correction duty DVTC.

Further, a correction rotation angle and a target relative rotation angle deviation DELTAC (= target relative rotation angle TAC−smoothing target relative rotation) corresponding to the amount of change of the target relative rotation angle TAC every predetermined cycle (for example, 360 ° CA). The feedback correction duty DVFB may be corrected by the sum of the correction rotation angle and the correction rotation angle according to the angle TACSM.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a double overhead cam type internal combustion engine to which a valve timing control device for an internal combustion engine according to an embodiment of the present invention is applied, and peripheral devices thereof.

FIG. 2 is a flowchart illustrating a processing procedure of an ECU used in a valve timing control device for an internal combustion engine according to an example of the embodiment of the present invention.

FIG. 3 is a map for obtaining a target relative rotation angle in FIG. 2;

FIG. 4 is a time chart showing a transition state between a target relative rotation angle and a smoothed target relative rotation angle in the valve timing control device for an internal combustion engine according to one embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 internal combustion engine 11 crankshaft (drive shaft) 12 chain 13 chain sprocket 15 camshaft (driven shaft) 21 crank position sensor 22 cam position sensor 30 ECU (electronic control device) 40 spool valve 41 linear solenoid 50 valve timing control mechanism

Claims (3)

[Claims] 1. A driving force transmission system for transmitting a driving force from a driving shaft of an internal combustion engine to a driven shaft for opening and closing at least one of an intake valve and an exhaust valve, wherein the driving shaft or the driven shaft is A valve timing control mechanism capable of rotating one side relatively within a predetermined angle range, a drive shaft rotation angle detection unit for detecting a rotation angle of the drive shaft, and a driven shaft rotation angle detection unit for detecting a rotation angle of the driven shaft. A relative rotation for calculating a relative rotation angle which is a phase difference between the rotation angle of the drive shaft detected by the drive shaft rotation angle detection means and the rotation angle of the driven shaft detected by the driven shaft rotation angle detection means; Angle calculation means, and target relative rotation angle calculation means for calculating a target relative rotation angle which is a target phase difference between the rotation angle of the drive shaft and the rotation angle of the driven shaft in accordance with the operation state of the internal combustion engine. The phase A control rotation angle is calculated in accordance with a deviation between the relative rotation angle calculated by the rotation angle calculation means and the target relative rotation angle calculated by the target relative rotation angle calculation means, and the driving is performed by the valve timing control mechanism. Relative rotation angle control means for relatively rotating a shaft or the driven shaft; and a transient correction rotation angle for calculating a transient correction rotation angle at the time of transition corresponding to the target relative rotation angle calculated by the target relative rotation angle calculation means. Computing means, and control rotation angle correction means for correcting the control rotation angle calculated by the relative rotation angle control means based on the transient correction rotation angle calculated by the transient correction rotation angle calculation means. A valve timing control device for an internal combustion engine. 2. The transient correction rotation angle calculating means calculates the transient correction rotation angle according to a deviation between the target relative rotation angle and a smoothed value obtained by smoothing the target relative rotation angle. The valve timing control device for an internal combustion engine according to claim 1, wherein 3. The valve timing control device for an internal combustion engine according to claim 1, wherein the transient correction rotation angle calculation means calculates the transient correction rotation angle based on a change amount of the target relative rotation angle. .