JP2001182569A - Control device for internal combustion engine - Google Patents

Abstract

(57) [Problem] To provide a control device for an internal combustion engine in which the engine performance is improved in an idling operation state. SOLUTION: In an idle state, in a region where the oil temperature is equal to or lower than T0 (for example, −10 ° C.) or equal to or higher than T1, that is, a non-operating region and a target variable region, the valve operating characteristic variable mechanism is fixed at the most retarded angle. The engine ignition timing and / or the amount of air supplied to the engine are controlled based on an idle ignition timing table and an idle air amount table, respectively. On the other hand, in the region where the engine temperature is higher than T0 and equal to or lower than T1, that is, in the target constant region, the cam phase has a constant angle (for example, 10 ° to 15 °).
°) The ignition timing is advanced and fixed, and the ignition timing of the engine and the amount of air supplied to the engine, or any one of them, is corrected based on the correction amounts detected in the ignition timing correction table and the air amount correction table, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an internal combustion engine having variable valve operating characteristics of intake and exhaust valves.

[0002]

2. Description of the Related Art An internal combustion engine equipped with a variable valve operating characteristic mechanism (hereinafter referred to as a variable valve operating characteristic mechanism) of a variable cam phase type for continuously controlling the opening and closing timings of intake and exhaust valves. Is disclosed in JP-A-59-93.
No. 964 and Japanese Patent Publication No. 5-43847.

Such a variable valve operating characteristic mechanism is usually
Feedback control is performed so that the actual cam phase matches the target cam phase calculated based on the operating state. However, since the valve operating characteristic variable mechanism is controlled by hydraulic pressure, the temperature of the hydraulic oil is low and the viscosity is high at a low temperature of the internal combustion engine, so that the flow speed of the hydraulic oil is reduced, and the accuracy of the feedback control is reduced. There was a problem of doing. On the other hand, due to the above-mentioned problem,
Fix the cam phase of the lube operation characteristic variable mechanism to the most retarded angle.
In this state, it is considered that
Because the overlap is the smallest,
A problem that the output of the fuel engine
You. To solve this problem, the cam phase must be
Japanese Patent Application Laid-Open No. H11-210424 discloses that a constant angle advance is required.
Information has been proposed.

[0004]

As described above, during idling of the internal combustion engine, the exhaust gas recirculation amount is reduced by setting the cam phase to the most retarded angle and reducing the valve overlap, thereby reducing the rotational speed of the internal combustion engine. Since the stabilization is generally performed, the control amount during idling, i.e., the idle speed, the supply air amount during idling, the ignition timing, etc.
The cooling water temperature of the internal combustion engine is set as a parameter on the assumption that the cam phase is at the most retarded angle.

However, since the temperature of the hydraulic oil and the temperature of the cooling water tend to increase rapidly at the start of the internal combustion engine, the temperature of the hydraulic oil must be low as described above. When the cam phase is advanced by a constant angle, the supply air amount or ignition timing required to maintain a predetermined idle speed is a value set on the assumption that the cam phase is the most retarded. And the rotational speed of the internal combustion engine may be temporarily unstable.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a control device for an internal combustion engine in which the engine performance is improved in an idling operation state. Specifically, the engine temperature is within a predetermined temperature range.
When the cam phase is advanced by a certain angle.
Of the amount of air supplied to the engine or the ignition timing
By correcting at least one control amount, the internal combustion engine
Control device for internal combustion engine that can stabilize engine speed
The purpose is to provide a device.

[0007]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
The invention described in claim 1 is an internal combustion engine (in the embodiment,
Depending on the operating state of the engine E), the intake valve or the exhaust valve
Change at least one valve timing by hydraulic pressure
Valve timing changing means (in the embodiment, the valve operation
A dynamic characteristic variable mechanism V) and a temperature associated with the internal combustion engine.
Temperature detecting means for detecting (oil temperature sensor in the embodiment)
And when the temperature is within a predetermined range (in the embodiment,
Means that the engine temperature is greater than T0 (eg, −10 ° C.) and T
1 (for example, 20 ° C.) or less, that is, a target constant area.
Control) by the valve timing changing means.
Control the valve timing to the specified valve timing
(In the embodiment, a constant angle advance is made with respect to the most retarded timing.
Valve timing, for example, advanced by 10 ° to 15 °
), And an idle speed of the engine.
Speed control means for controlling the engine speed to a predetermined speed
And a control device for an internal combustion engine comprising:
When valve timing is fixed by fixing means
The control amount of the idle speed control means (embodiment
In the state, the amount of air supplied to the internal combustion engine and the ignition of the internal combustion engine
Characteristic value correction means for correcting the timing)
And

[0008] As described above, the temperature of the internal combustion engine is reduced to a predetermined temperature range.
Range, the cam phase must be advanced by a certain angle.
The amount of air supplied to the internal combustion engine or the ignition
By correcting at least one of the control variables
The rotational speed of the fuel engine can be stabilized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, FIG. 1 shows a schematic diagram of the entire configuration of an internal combustion engine according to a position embodiment of the present invention. In the figure, a DOHC type internal combustion engine E has a piston 1 for each cylinder, and the piston 1 is connected to a crankshaft 3 via a connecting rod 2. Further, a driving sprocket 4 provided at the shaft end of the crankshaft 3 and driven sprockets 7 and 8 laid respectively at the shaft ends of the intake camshaft 5 and the exhaust camshaft 6 are connected via a timing chain 9. The intake camshaft 5 and the exhaust camshaft 6 are driven to rotate at a rate of one rotation for every two rotations of the crankshaft 3.

The engine E has a pair of intake valves 10 driven by an intake camshaft 5 for each cylinder.
A variable valve operation characteristic mechanism V is provided at the shaft end of the intake camshaft 5 to continuously advance or retard the opening / closing timing of the intake valve 10.

Next, referring to FIGS. 2 and 3, the structure of the valve operating characteristic variable mechanism V provided at the shaft end of the intake camshaft 5 will be described. In the figure, a support hole 41-1 formed at the center of a substantially cylindrical boss member 41 is coaxially fitted to the shaft end of the intake camshaft 5, and is coupled with a pin 42 and a bolt 43 so as not to rotate relatively. . The driven sprocket 7 around which the timing chain 9 (see FIG. 1) is wound
Is formed in a substantially cup shape having a circular concave portion 7-1, and sprocket teeth 7-2 are formed on the outer periphery thereof.
An annular housing 44 that fits into the recess 7-1 of the driven sprocket 7 and a plate 45 that is superposed axially outside thereof are connected to the driven sprocket 7 by bolts 46 that pass therethrough. Therefore, the boss member 41 integrally connected to the intake camshaft 5 is rotatably housed in a space surrounded by the driven sprocket 7, the housing 44 and the plate 45.

A pin hole 4 penetrating the boss member 41 in the axial direction.
A lock pin 47 is slidably fitted to 1-2 and is engaged with a lock hole 7-3 formed in the driven sprocket 7 by a spring 48 mounted in a compressed state between the lock pin 47 and the plate 45. It is urged in the direction to match.

Inside the housing 44, four fan-shaped recesses 44-1 centered on the axis are formed in the intake camshaft 5 at intervals of 90 °, and four fan-shaped concave portions 44-1 project radially from the outer periphery of the boss member 41. The vane 49 is fitted into the concave portion 44-1 so that the vane 49 can relatively rotate within a central angle range of 30 °. 4
Seal members 5 provided at the tips of the vanes 49
0 slidably abuts the ceiling wall of the concave portion 44-1 so that the advance chamber 52 and the retard chamber 53 are provided on both sides of each vane 49.
Are respectively partitioned.

An advancing oil passage 54 and a retarding oil passage 55 are formed inside the intake camshaft 5, and the advancing oil passage 54 includes four oil passages penetrating through the boss member 41 in the radial direction. Road 5
6, and the retarding oil passage 55 is connected to the four retarding chambers 53 through four oil passages 57 penetrating through the boss member 41 in the radial direction. Communicate with each other. Further, the lock hole 7-3 of the driven sprocket 7 into which the head of the lock pin 47 is fitted communicates with one of the advance chambers 52 via an oil passage (not shown).

When the hydraulic pressure is not supplied to the advance chamber 52, the head of the lock pin 47 is fitted into the lock hole 7-3 of the driven sprocket 7 by the resilience of the spring 48.
As shown in (1), the intake camshaft 5 is locked in the most retarded state (most displacement reference position) in which the intake camshaft 5 is rotated counterclockwise relative to the driven sprocket 7.

When the hydraulic pressure supplied to the advance chamber 52 is increased from this state, the lock pin 47 is pressed against the resilient force of the spring 48 by the hydraulic pressure transmitted from any of the advance chambers 52, and As the vane 49 is released from the lock hole 7-3 and the vane 49 is pushed by the hydraulic pressure difference between the advance chamber 52 and the retard chamber 53, the intake camshaft 5 moves clockwise with respect to the driven sprocket 7 (in FIG. The engine E relatively rotates in the counterclockwise direction opposite to the rotation direction of the crankshaft 3 of the internal combustion engine E), so that both the valve opening timing advances and both the valve opening timing and the valve closing timing of the intake valve 10 change to the advance side. Therefore, by controlling the hydraulic pressures of the advance chamber 52 and the retard chamber 53, the opening / closing timing of the intake valve 10 can be changed steplessly.

Next, a control system of the variable valve operation characteristic mechanism V will be described with reference to FIG. In the figure, the oil pumped up by an oil pump 61 from an oil pan 62 at the bottom of the crankcase via an oil passage L1 is used around the crankshaft 3 of the internal combustion engine E, as lubricating oil for a valve mechanism, and for valve operation. Oil passage L2 as the hydraulic oil
And is supplied to a valve operating characteristic variable mechanism V via a hydraulic control valve 64 composed of a duty solenoid valve for continuously controlling the hydraulic pressure.

On the other hand, the electronic control unit U receives a signal from the camshaft sensor S1 for detecting the phase of the intake camshaft 5 and a TDC sensor S2 for detecting the top dead center of the piston 1 based on the phase of the exhaust camshaft 6. , A signal from a crankshaft sensor S3 for detecting the phase of the crankshaft 3, a signal from an intake negative pressure sensor S4 for detecting an intake negative pressure, a signal from a cooling water temperature sensor S5 for detecting a cooling water temperature, and a throttle opening. , A signal from an engine speed sensor S7 for detecting an engine speed, and a signal from an oil temperature sensor for detecting the temperature of hydraulic oil (not shown).
By controlling the hydraulic control valve 64 based on these, the valve operating characteristic variable mechanism V is controlled.

Next, the hydraulic control valve 6 described above with reference to FIG.
The structure of No. 4 will be described. The hydraulic control valve 64 includes a cylindrical sleeve 65, a spool 66 slidably fitted inside the sleeve 65, a duty solenoid 67 fixed to the sleeve 65 to drive the spool 66, and a duty solenoid And a spring 68 for urging toward 67. Electronic control unit U (FIG. 4)
By controlling the duty of the current of the duty solenoid 67 in accordance with a command from the controller 65, the axial position of the spool 66 slidably fitted to the sleeve 65 can be changed steplessly.

The sleeve 65 is provided with a central input port 69, a retard port 70 and an advance port 71 located on both sides thereof, and a pair of drain ports 72 and 73 located on both sides thereof. You. On the other hand, a spool 66 slidably fitted to the sleeve 65 has a central groove 74 and a pair of lands 75 and 76 located on both sides thereof.
And a pair of grooves 77, 78 located on both sides thereof
Are formed. The input port 69 is connected to the oil pump 61
The retard port 70 is connected to the retard chamber 53 of the variable valve operation characteristic mechanism V, and the advance port 71 is connected to the advance chamber 52 of the variable valve operation mechanism V.

Next, the basic operation of the variable valve operating characteristic mechanism V will be described in detail. First, when the internal combustion engine is stopped, the retard chamber 53 of the variable valve operating characteristic mechanism has a maximum volume and the volume of the advance chamber 52 has become zero as shown in FIG. 47 is held in the most retarded state in which it is fitted into the lock hole 7-3 of the driven sprocket 7. Next, when the internal combustion engine is started, the oil pump 61 (see FIG. 4) is operated, and the advance chamber 52 through the hydraulic control valve 64 is operated.
If the hydraulic pressure transmitted to the lock pin 47 exceeds a predetermined value (for example, 1 kg / cm ² ), the lock pin 47 locks the lock hole 7-3 by the hydraulic pressure.
And the variable valve operating characteristic mechanism V is in an operable state.

In order to continuously change the cam phase of the intake camshaft 5 to the advanced side from this state, the duty ratio of the duty solenoid 67 is increased to 50% or more, and the spool 66 is moved from the neutral position to the left in FIG. Then, the input port 69 connected to the oil pump 61 is connected to the advance port 71 via the groove 74, and the retard port 70 is connected to the drain port 72 via the groove 77. As a result, the hydraulic pressure is actuated in the advance chamber 52 of the valve operating characteristic variable mechanism V, and in FIG.
, The intake camshaft 5 rotates clockwise,
The cam phase of the intake camshaft 5 continuously changes to the advance side.

When the target cam phase is obtained, the duty ratio of the duty solenoid 67 is set to a predetermined value (for example, 50%), and the spool 66 of the hydraulic control valve 64 is stopped at the neutral position shown in FIG. And input port 69
Is closed between the pair of lands 75 and 76, whereby the driven sprocket 7 and the intake camshaft 5 can be integrated to maintain the cam phase.

On the other hand, in order to continuously change the cam phase of the camshaft 5 to the retard side, the duty solenoid 67
And reduce the duty ratio of the spool 6 to 50% or less.
5 is moved to the right from the neutral position in FIG. 5, the input port 69 connected to the oil pump 61 is connected to the retard port 70 via the groove 74, and the advance port 71 is connected to the drain port 73 via the groove 78. You can do it. When the target phase is obtained, the duty ratio of the duty solenoid 67 is set to 50% and the spool 66 is stopped at the neutral position shown in FIG. The port 71 can be closed to maintain the cam phase.

Next, the control of the variable valve operating characteristic mechanism V when the operating state is the idle state will be described with reference to FIG. It should be noted that whether or not the idle state
Signal from throttle opening sensor S6, rotation speed sensor S
7 is determined by the electronic control unit U based on the signal from the control unit 7. That is, when the throttle opening is fully closed and at a predetermined low speed, the electronic control unit U determines that the engine is in an idle state.

FIG. 6 is a diagram showing an operating region of the valve operating characteristic variable mechanism V in an idle state. As shown in this figure, the operating range of the valve operating characteristic variable mechanism V is the engine temperature (for example, the oil temperature detected by an oil temperature sensor, or the oil temperature estimated from the cooling water temperature and the operating time from the start of the internal combustion engine). Thus, there are three regions: a non-operation region, a constant target region, and a target variable region. When the engine temperature is equal to or lower than T0 (for example, −10 ° C.), a non-operating region is set, and the target cam phase is fixed to the most retarded angle. Also,
Engine temperature is greater than T0 and T1 (for example, + 20 ° C.)
The following area is a target constant area, and the target cam phase is advanced by a certain angle (for example, 10 ° to 15 °). Further, when the engine temperature is higher than T1, the target variable region is set, and the cam phase is fixed to the most retarded angle.

On the other hand, at the time of idling, for example, an AIR amount (air amount) supplied to the engine by a bypass valve (not shown) for bypassing the throttle is determined based on an idle AIR table shown in FIG. This figure is
Indicates the basic AIR amount for achieving the target idle speed determined by the water temperature. The higher the cooling water temperature, the lower the target idle speed.
The R amount depends on the water temperature of the engine, and the higher the water temperature, the more the AIR
The amount is set low. Further, as the actual AIR amount to the bypass valve, a correction value corresponding to the deviation from the target idle speed is also supplied. In addition, the above idle AI
Since the R amount is a value when the target cam phase of the variable valve operation characteristic mechanism V is fixed at the most retarded angle, FIG.
It is necessary to correct the AIR amount depending on the operating region of the variable valve operating characteristic mechanism V described in (1).

Referring to FIG. 7, the process of determining the correction of the idle AIR amount in each operating region of the variable valve operating characteristic mechanism V will be described. First, in step S1, it is determined whether the engine temperature is higher than T0. If it is determined that the engine temperature is equal to or lower than T0 (NO in step S1), the variable valve operating characteristic mechanism V is set to non-operation in step S2, that is, the target cam phase is fixed to the most retarded angle, and in subsequent step S5 Idol AIR
It is determined that there is no correction, and the process ends. Accordingly, in this region, the target cam phase of the variable valve operation characteristic mechanism V is set to the most retarded angle, and thus the amount of AIR supplied to the engine is controlled based on the graph shown in FIG.

On the other hand, if it is determined in step S1 that the engine temperature is higher than T0 (YES in step S1), the process proceeds to step S3 to determine whether the engine temperature is higher than T1. If it is determined that the engine temperature is higher than T1 (step S3 is YE
S), the process proceeds to step S4 and the valve operating characteristic variable mechanism V
Is set as a target variable region, that is, the target cam phase is fixed at the most retarded angle, and the idle AI
It is determined that there is no R correction, and the process ends. Also in this region, the target cam phase is fixed to the most retarded angle, similarly to the above-described region, so that the AIR amount is controlled based on the graph shown in FIG.

If it is determined in step S3 that the engine temperature is equal to or lower than T1, that is, if the engine temperature is lower than T1.
If it is determined that the value is greater than 0 and equal to or less than T1, the process proceeds to step S6, where the operation region of the valve operating characteristic variable mechanism V is set to the target constant region, that is, the target cam phase is advanced by a fixed angle and fixed, and step S7 is performed. Move to. Step S7
Then, the correction of the AIR amount is performed based on the idle AIR correction table. FIG. 9 shows an idle AIR correction table. In the figure, the horizontal axis represents the temperature of the cooling water of the engine, and the vertical axis represents the AIR correction amount. Step S
In step 7, an AIR correction amount corresponding to the temperature of the engine cooling water is detected with reference to this table, and the detected AI correction amount is determined.
The AIR amount is corrected based on the R correction amount. As described above, the process ends when the correction of the AIR amount is completed.

FIG. 10 shows the transition of the cam phase with respect to the engine temperature and the transition of the amount of AIR supplied to the engine. In the figure, in the region where the engine temperature is equal to or lower than T0, and in the region where the engine temperature is equal to or higher than T1, that is, in the non-operation region and the target variable region, the cam phase is fixed at the most retarded angle, and the AIR amount supplied to the engine. Is controlled based on the idle AIR table shown in FIG.

On the other hand, if the engine temperature is higher than T0 and T
In a region equal to or less than 1, that is, a constant target region, the cam phase is fixed by being advanced by a constant angle (for example, 10 ° to 15 °), and the amount of AIR supplied to the engine is determined by the AIR in the idle AIR table shown in FIG. The amount is a value corrected based on the AIR correction table shown in FIG. That is, AIR
The amount is a value obtained by adding the AIR correction amount shown in FIG. 9 to the AIR amount shown in FIG.

Next, the engine ignition timing θIG during idling operation will be described. FIG. 12 shows an idle ignition timing θIG table. In the figure, the horizontal axis represents the temperature of the cooling water of the engine, and the vertical axis represents the ignition timing θIG. As described above, the ignition timing θIG at the time of idling is set based on the temperature of the engine coolant similarly to the above-described AIR amount. Similarly, correction according to the deviation from the target idle speed is also added as the actual ignition timing. Hereinafter, with reference to FIG.
The correction determination processing of the engine ignition timing θIG amount in each operation region will be described. First, in step S21, it is determined whether the engine temperature is higher than T0. If it is determined that the engine temperature is equal to or lower than T0 (NO in step S21), the variable valve operation characteristic mechanism V is set to non-operation in step S22, that is, the target cam phase is fixed to the most retarded angle, and in subsequent step S25. It is determined that there is no idle ignition timing correction, and the process ends. Therefore, in this region, the target cam phase of the variable valve operation characteristic mechanism V is set to the most retarded angle, so that the engine ignition timing θI
G is controlled based on the idle ignition timing θIG table shown in FIG.

On the other hand, if it is determined in step S21 that the engine temperature is higher than T0 (step S2).
(1 is YES), the process proceeds to step S23, and it is determined whether the engine temperature is higher than T1. Engine temperature is T
If it is determined that it is greater than 1 (YES in step S23), the process proceeds to step S24, where the operation region of the variable valve operation characteristic mechanism V is set to the target variable region, that is, the target cam phase is fixed to the most retarded angle. Then, in the subsequent step S25, it is determined that the idle ignition timing is not corrected, and the process ends. Also in this region, the target cam phase is fixed to the most retarded angle, similarly to the above-described region, and therefore, the ignition timing is controlled based on the idle ignition timing θIG table shown in FIG.

If it is determined in step S23 that the engine temperature is equal to or lower than T1, that is, if the engine temperature is lower than T1.
If it is determined that the value is greater than 0 and equal to or less than T1, the process proceeds to step S26, in which the operation region of the valve operating characteristic variable mechanism V is set to the target constant region, that is, the target cam phase is advanced by a fixed angle and fixed, and step S27 is performed. Move to. In step S27, the ignition timing is corrected based on the idle ignition timing θIG correction table. FIG. 13 shows an idle ignition timing correction table. In the figure, the horizontal axis represents the temperature of the cooling water of the engine, and the vertical axis represents the ignition timing correction amount. In step S27, an ignition timing correction amount corresponding to the temperature of the engine coolant is detected with reference to this table, and the ignition timing θ is determined based on the detected ignition timing correction amount.
IG is corrected. As described above, when the correction of the ignition timing θIG is completed, the process ends.

FIG. 14 shows the transition of the cam phase with respect to the engine temperature and the transition of the ignition timing θIG. In the figure, in the region where the engine temperature is T0 or lower, and in the region where the engine temperature is T1 or higher, that is, in the non-operation region and the target variable region, the cam phase is fixed at the most retarded angle, and the ignition timing θIG of the engine is The control is performed based on the idle ignition timing table shown in FIG.

On the other hand, if the engine temperature is higher than T0 and T
In the region equal to or less than 1, that is, in the constant target region, the cam phase is fixed by being advanced by a constant angle (for example, 10 ° to 15 °), and the ignition timing θIG of the engine is calculated by the idle ignition timing correction table shown in FIG. Depending on the detected correction amount,
This is a value obtained by correcting the ignition timing in the idle ignition timing table shown in FIG. That is, the ignition timing is a value obtained by adding the ignition timing correction amount shown in FIG. 13 to the value of the ignition timing θIG shown in FIG. In the present embodiment, the correction is performed for both the air amount and the ignition timing. However, a configuration in which only one of them is performed may be used. Further, in the present embodiment, the valve timing changing means for changing the phase of the valve opening is provided on the intake side, but may be provided on the exhaust side, or a means for changing the valve lift may be used together. Is also good.

[0038]

As described above, according to the control apparatus for an internal combustion engine of the present invention, when the temperature of the internal combustion engine is within the predetermined range and the valve timing is fixed at the predetermined valve timing, the idle control is performed. By correcting the control amount by the rotation speed control means, temporary instability of rotation of the internal combustion engine can be avoided, and high-precision engine control can be realized.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 6-6 in FIG. 2;

FIG. 4 is a hydraulic circuit diagram of the valve operating characteristic variable mechanism in the embodiment.

FIG. 5 is a longitudinal sectional view of a hydraulic control valve.

FIG. 6 is a view showing an operation region of a variable valve operation characteristic mechanism.

FIG. 7 is a flowchart showing an idle AIR correction process in the embodiment.

FIG. 8 is a diagram showing an idle AIR table in the embodiment.

FIG. 9 is a diagram showing an idle AIR correction table in the embodiment.

FIG. 10 shows a cam phase and idle A in the embodiment.
It is a figure showing transition of IR amount.

FIG. 11 is a flowchart showing an idle ignition timing correction process in the embodiment.

FIG. 12 is a diagram showing an idle ignition timing table in the embodiment.

FIG. 13 is a diagram showing an idle ignition timing correction table in the embodiment.

FIG. 14 is a diagram showing changes in cam phase and idle ignition timing in the same embodiment.

[Explanation of symbols]

 E internal combustion engine V valve operating characteristic variable mechanism U electronic control unit 5 intake camshaft 6 exhaust camshaft 64 hydraulic control valve S4 intake negative pressure sensor S5 cooling water temperature sensor S6 throttle opening sensor

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Junichi Suzuki 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (Reference) 3G092 AA11 DA01 DA02 DA09 DC04 DG05 DG07 EA03 EA04 EA13 EC08 EC09 FA00 FA06 GA04 HA05Z HA06Z HE01X HE01Z HE03Z HE08Z 3G301 HA01 HA19 JA00 KA07 LA04 LC01 LC08 NC02 ND41 NE11 NE12 NE16 PA07Z PA11Z PE01A PE01Z PE03Z PE08Z

Claims (1)

[Claims] 1. A valve timing changing means for changing a valve timing of at least one of an intake valve and an exhaust valve by oil pressure according to an operation state of an internal combustion engine, and a temperature detecting means for detecting a temperature related to the internal combustion engine. When the temperature is within a predetermined range, fixing means for fixing the valve timing controlled by the valve timing changing means to a predetermined valve timing; and setting the idle speed of the engine to a predetermined speed. A control value for correcting a control amount of the idle speed control means when the valve timing is fixed by the fixing means. A control device for an internal combustion engine, comprising a calculating means.