JPH06330716A - Valve timing control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To obtain responsiveness of a high valve timing at the time of acceleration and deceleration. CONSTITUTION:In a case of deceleration a target advance angle amount is calculated by an ECU 70, on the basis of the map of an intake air amount GN and an engine rotating speed NE. By means of the ECU 70, a VVT(a variable valve timing mechanism) 23 is driven on the basis of a target advance angle value when the target advance angle amount stays on a delay angle side, and a second OSV 54 is turned on while turning off a first OSV(oil switching valve) 53 in order to delay the opening/closing timing of an intake valve 8. By means of the ECU 70, the target advance angle amount is calculated on the basis of the map of a throttle opening degree TA and the engine rotating speed NE in the case of acceleration, the VVT 23 is driven on the basis of the target advance angle value when the target advance angle amount stays at an advance angle side, and the second OSV 54 is turned off while turning on the first OSV 53 in order to advance the opening/closing timing of the intake valve 8.

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 device equipped with a variable valve timing mechanism for continuously changing the opening / closing timing of an intake valve or an exhaust valve according to the operating state of an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, as disclosed in JP-A-59-120707, based on the load and the rotational speed of an internal combustion engine,
The valve timing is properly controlled to improve engine performance. The load includes an intake air amount, a throttle opening, and the like. The intake air amount indicates the actual operating condition of the engine, but is inferior in stability and responsiveness. On the other hand, although the throttle opening is excellent in transient response, it is difficult to say that the throttle opening always matches the actual operating condition of the engine, and it is difficult to perform optimum valve timing control.

For example, in a hydraulically driven variable valve timing mechanism, there is a variable valve timing mechanism of one type in which one side is hydraulically driven and the other side is spring driven. This variable valve timing mechanism advances the angle against the drive torque of the cam. Therefore, the operation in the advance direction is slower than the operation in the retard direction, and the operation in the retard direction is in the advance direction. Compared with, it has the characteristic of being sufficiently fast.

During deceleration, the operation in the retard direction is more frequent than the operation in the advance direction. Therefore, during deceleration, the operation is fast and there is sufficient followability with respect to the target advance value. Further, during acceleration, there are many operations in the advancing direction, so during acceleration, the operation of the variable valve timing mechanism is slow.

In the conventional variable valve timing mechanism, a map of intake air amount GN and engine speed NE (hereinafter referred to as GN-NE map), a map of throttle opening TA and engine speed NE (hereinafter TA-). N
Target advance angle value OCA
M was determined, and control was performed with the smaller target advance value.

The reason for this is as follows. FIG. 11 shows the time change of the throttle opening TA at the time of acceleration, and FIG. 12 shows the time change when the target advance value OCAM is obtained with reference to the GN-NE map and the TA-NE map.
In addition, E represents the target advance value OCAM obtained by referring to the TA-NE map, and F represents the target advance value OCAM obtained by referring to the GN-NE map.

When the variable valve timing mechanism has no operation delay, the target advance value OCAM obtained from the TA-NE map
When controlled by (E in FIG. 12), the intake valve opens faster with respect to the actual air amount, so the internal EGR increases too much and combustion deteriorates.

FIG. 7 shows the time change of the throttle opening TA during deceleration, and FIG. 8 shows the time change when the target advance value OCAM is obtained with reference to the GN-NE map and the TA-NE map. . In addition, B represents the target advance value OCAM obtained by referring to the TA-NE map, and A represents GN-NE.
The target advance value OCAM is represented by referring to the map. Target advance value OCCAM obtained from GN-NE map
In (A of FIG. 8), since the actual intake air amount is smoothed, a slight delay occurs in the fall.

In this case, if there is a delay in the operation of the variable valve timing control mechanism, the intake valve opens much faster than the actual intake air amount, so that the internal EGR is too large and combustion deteriorates.

For the above reasons, in the acceleration / deceleration state, the internal EGR is controlled on the safe side so that the internal EGR is on the decreasing side in order to prevent deterioration of combustion caused by excessive internal EGR. That is, TA-NE map, GN-NE
The smaller target advance angle value obtained from the map is used for control.

[0011]

For the above reason, conventionally, during deceleration, the target advance value (B in FIG. 8) determined by the TA-NE map is the target advance value (determined by the GN-NE map). Since the fall is earlier and the target advance value is smaller than that in A) of FIG. 8, the control is performed with the target advance value obtained from the TA-NE map.

However, the target advance value obtained from the TA-NE map is much smaller than the actual intake air amount, and as described above, it is an excessive retardation angle during deceleration with good followability, and the internal E
There was a problem that GR could not be secured sufficiently. Therefore, H
Exhaust gases such as C and NOx increase.

On the other hand, when accelerating, the TA-N
For the target advance value (E in FIG. 12) obtained from the E map, G
Since the target advance value (F in FIG. 12) obtained by the N-NE map is smaller, the control is performed by the target advance value obtained by the GN-NE map. However, since the target advance value (F in FIG. 12) obtained by the GN-NE map has a slower rise than the target advance value (E in FIG. 12) obtained by the TA-NE map, the variable valve timing mechanism Responsiveness will be further deteriorated.

An object of the present invention is to provide a valve timing control device for an internal combustion engine which can obtain a high valve timing response during acceleration and deceleration.

[0015]

In order to achieve the above object, in the present invention, as shown in FIG. 1, an intake passage M3 which is driven in synchronization with the rotation of an internal combustion engine M1 and communicates with a combustion chamber M2 and An intake valve M5 and an exhaust valve M6 for respectively opening and closing the exhaust passage M4, and an intake valve M5
A variable valve timing mechanism M7 driven to make the opening / closing timing of the engine variable, an operating state detecting means M8 for detecting the operating state of the internal combustion engine M1, and a detection result of the operating state detecting means M8, The variable valve timing mechanism M for controlling the valve overlap amount.
In the valve timing control device for an internal combustion engine, which includes a drive control means M9 for driving and controlling 7, a determination means M10 for determining a specific engine state based on a detection result of the operating state detection means M8 and a determination means M10 for determination. Based on the detection result of the operating state detecting means M8, based on the detection result of the operating state detecting means M8, the target advance value of the valve timing obtained from the intake air amount and the engine speed, and the detection result of the operating state detecting means M8. Selection means M11 for selecting a target advance value of valve timing whose target advance value is on the advance side among the target advance values of valve timing obtained from the throttle opening and the engine speed, and the selection means. The control range of the variable valve timing mechanism M7 in the drive control means M9 is changed by the target advance value of the valve timing selected by M11. Is the gist that a corner amount changing means M12.

According to a second aspect of the present invention, the intake valve and the exhaust valve, which are driven at a predetermined timing in synchronization with the rotation of the internal combustion engine and respectively open and close the intake passage and the exhaust passage leading to the combustion chamber, the intake valve and the exhaust valve, respectively. A variable valve timing mechanism for varying at least one of the exhaust valves to vary the valve overlap amount, an operating state detecting means for detecting an operating state of the internal combustion engine, and a detection result of the operating state detecting means. A valve timing control device for an internal combustion engine, comprising: a drive control means for driving and controlling the variable valve timing mechanism to control the valve overlap amount, during deceleration according to a detection result of a throttle opening degree of the operating state detection means. Deceleration state determining means for determining whether or not the operation is performed when the deceleration state determining means determines that the vehicle is decelerating. First valve timing target advance value selecting means for selecting a target advance value of valve timing obtained from the intake air amount and engine speed based on the detection result of the state detecting means, and the first valve timing target. The gist of the present invention is to provide second advance angle changing means for changing the control range of the variable valve timing mechanism in the drive control means with the target advance value of the valve timing selected by the advance value selecting means. There is.

According to a third aspect of the present invention, an intake valve and an exhaust valve which are driven at a predetermined timing in synchronization with the rotation of the internal combustion engine to open and close an intake passage and an exhaust passage leading to the combustion chamber, the intake valve and the exhaust valve, respectively. A variable valve timing mechanism for varying at least one of the exhaust valves to vary the valve overlap amount, an operating state detecting means for detecting an operating state of the internal combustion engine, and a detection result of the operating state detecting means. A valve timing control device for an internal combustion engine, comprising: a drive control means for driving and controlling the variable valve timing mechanism to control the valve overlap amount, during acceleration based on a detection result of a throttle opening degree of the operating state detection means. Acceleration state determining means for determining whether or not the operation is performed when the acceleration state determining means determines that acceleration is in progress. Second valve timing target advance value selection means for selecting a target advance value of valve timing obtained from the throttle opening and the engine speed based on the detection result of the state detection means; and the second valve timing target. The gist of the present invention is to provide third advance angle changing means for changing the control range of the variable valve timing mechanism in the drive control means with the target advance value of the valve timing selected by the advance value selecting means. There is.

[0018]

According to the above construction, as shown in FIG. 1, the intake valve M5 and the exhaust valve M are operated when the internal combustion engine M1 is in operation.
6 is driven in synchronization with the rotation of the internal combustion engine M1, and the combustion chamber M
The intake passage M3 and the exhaust passage M4 which communicate with 2 are opened and closed to intake and exhaust the combustion chamber M2. Further, the drive control means M10 controls the variable valve timing mechanism M7.
Is controlled to change the opening / closing timing of the intake valve M5. Also, this allows the intake valve M5
The valve overlap between the exhaust valve M6 and the exhaust valve M6 is changed.

Then, the judging means M10 judges the specific engine state based on the detection result of the operating state detecting means M8.
When the selecting means M11 is in the specific engine state determined by the determining means M10, the target advance value of the valve timing obtained from the intake air amount and the engine speed based on the detection result of the operating state detecting means M8, and the operating state A target advance value of valve timing whose target advance value is on the advance side is selected from the target advance values of valve timing obtained from the throttle opening and the engine speed based on the detection result of the detection means M8. To do. The first advance angle changing means M12 has the variable valve timing mechanism M7 in the drive control means M9 at the target advance value of the valve timing selected by the selecting means M11.
Change the control range of.

In the second aspect of the invention, the deceleration state determination means determines whether or not the vehicle is decelerating based on the detection result of the throttle opening of the operating state detection means. The first valve timing target advance value selecting means determines the valve timing obtained from the intake air amount and the engine speed based on the detection result of the operating state detecting means when the deceleration state determining means determines that the vehicle is decelerating. Select the target advance value. The second advance angle changing means changes the control range of the variable valve timing mechanism in the drive control means at the target advance value of the valve timing selected by the first valve timing target advance value selecting means.

According to the third aspect of the present invention, the acceleration state determination means determines whether or not acceleration is in progress based on the detection result of the throttle opening degree of the operating state detection means. The second valve timing target advance value selecting means, when the acceleration state determining means determines that acceleration is being performed, determines the valve timing obtained from the throttle opening and the engine speed based on the detection result of the operating state detecting means. Select the target advance value. The third advance angle changing means changes the control range of the variable valve timing mechanism in the drive control means at the target advance value of the valve timing selected by the second valve timing target advance value selecting means.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the valve timing control device for an internal combustion engine according to the present invention is embodied in a gasoline engine will be described in detail below with reference to FIGS.

FIG. 2 is a schematic configuration diagram showing a valve timing control device for an internal combustion engine in this embodiment. In an engine 1 as an internal combustion engine including a plurality of cylinders, a piston 3 is provided in a cylinder 2 for each cylinder so as to be vertically movable, and an upper side of each piston 3 is a combustion chamber 4. A spark plug 5 is provided in each combustion chamber 4. Further, an intake passage 6 and an exhaust passage 7 are provided in communication with each combustion chamber 4 through an intake port 6a and an exhaust port 7a. The intake port 6a and the exhaust port 7a are provided with an intake valve 8 and an exhaust valve 9 for opening and closing, respectively. These intake valves 8
The exhaust valve 9 is driven by the rotation of the intake camshaft 10 and the exhaust camshaft 11. An intake side timing pulley 12 and an exhaust side timing pulley 13 are provided at one end of each of the camshafts 10 and 11. Furthermore, each timing pulley 12, 13
Are drivingly connected to a crankshaft (not shown) via a timing belt 14.

Therefore, when the engine 1 is in operation, rotational power is transmitted from the crankshaft to the camshafts 10 and 11 via the timing belt 14 and the timing pulleys 12 and 13, and the intake air is generated by the rotation of the camshafts 10 and 11. The valve 8 and the exhaust valve 9 are opened and closed. Further, the opening / closing timings of the intake valve 8 and the exhaust valve 9 are predetermined in synchronization with the rotation of the crankshaft, that is, in synchronization with a series of four strokes of an intake stroke, a compression stroke, an explosion / expansion stroke and an exhaust stroke. It is opened and closed at the timing.

An air cleaner 15 is provided on the inlet side of the intake passage 6.
Is provided. An injector 16 for fuel injection is provided near the intake port 6a for each cylinder. Then, outside air is taken into the intake passage 6 through the air cleaner 15. Further, at the same time when the outside air is taken in, fuel is injected from each injector 16 into the intake port 6a. Then, in the engine 1, the mixture of the outside air and the fuel is introduced into the combustion chamber 4 in synchronization with the opening of the intake valve 8 in the intake stroke. Further, in the engine 1, the air-fuel mixture introduced into the combustion chamber 4 is exploded and burned by the ignition of the spark plug 5 to obtain a driving force. Further, the exhaust gas after combustion is led out from the exhaust port 7a in synchronization with the opening of the exhaust valve 9 in the exhaust stroke, and further, the exhaust passage 7
Is discharged to the outside through.

A throttle valve 17 which is opened and closed in conjunction with the operation of an accelerator pedal (not shown) is provided in the middle of the intake passage 6. By opening / closing the throttle valve 17, the intake air amount, which is the intake amount of the outside air into the intake passage 6, is adjusted. A surge tank 18 for smoothing the pulsation of intake air is provided downstream of the throttle valve 17 in the intake passage 6.
In addition, in the vicinity of the air cleaner 15 in the intake passage 6,
An intake air temperature sensor 61 for detecting the intake air temperature THA is provided. Similarly, in the vicinity of the air cleaner 15,
An air flow meter 62 for detecting the intake air amount is provided. In the vicinity of the throttle valve 17,
A throttle sensor 63 for detecting the throttle opening TA is provided.

On the other hand, in the middle of the exhaust passage 7, a catalytic converter 20 having a three-way catalyst 19 for purifying exhaust gas is provided. In the middle of the exhaust passage 7,
An oxygen sensor 64 is provided for detecting the oxygen concentration in the exhaust gas.

Further, the engine 1 is provided with a water temperature sensor 65 for detecting the temperature (cooling water temperature) THW of the cooling water. The ignition signal distributed by the distributor 21 is applied to each ignition plug 5 for each cylinder. The distributor 21 distributes the high voltage output from the igniter 22 to each spark plug 5 in synchronization with the rotation of the crankshaft, that is, the crank angle. The ignition timing of each spark plug 5 is determined by the high voltage output timing from the igniter 22.

The distributor 21 has a built-in rotor (not shown) which is connected to the exhaust side camshaft 11 and rotates in conjunction with the crankshaft. The distributor 21 is provided with a rotation speed sensor 66 for detecting the rotation speed (engine rotation speed) NE of the engine 1 from the rotation of the rotor. or,
The distributor 21 is also provided with a cylinder discrimination sensor 67 for detecting the crank angle reference position GP of the engine 1 at a predetermined rate in accordance with the rotation of the rotor. In this embodiment, the intake stroke of the engine 1,
Assuming that the crankshaft makes two revolutions for a series of four strokes including the compression stroke, the explosion / expansion stroke, and the exhaust stroke, the rotation speed sensor 66 detects the crank angle at a rate of 30 ° CA per pulse. Further, the cylinder discrimination sensor 67 detects the crank angle at a rate of 360 ° CA per pulse.

In this embodiment, an operating condition detecting means for detecting the operating condition of the engine 1 is constituted by the air flow meter 62, the throttle sensor 63, the rotational speed sensor 66 and the like.

In addition, in this embodiment, the intake side timing pulley 12 is provided with a variable valve timing mechanism (hereinafter simply referred to as "VVT") 23 driven by hydraulic pressure to make the opening / closing timing of the intake valve 8 variable. It is provided.

Here, the structure of the VVT 23 and the like will be described in detail with reference to FIG. The camshaft 10 has a cam journal 10 a whose cylinder head 1 is the engine 1.
It is rotatably supported between a and the bearing cap 1b. A VVT 23, which is provided integrally with the timing pulley 12, is provided at one end of the camshaft 10.

The timing pulley 12 has a plurality of outer teeth 31 on the outer periphery and a housing recess 32 on one side. In addition, the camshaft 1 covers the accommodation recess 32.
A cap 33 is fastened and fixed to the tip of 0 by a bolt 34. Further, between the opening end of the timing pulley 12 and the outer periphery of the cap 33, a well-known cushioning member including an outer plate 35 press-fitted and fixed to the pulley 12, an inner plate 36 formed on the cap 33, and the like. A viscous joint (viscus coupling) 37 is provided.

A ring gear 38 is interposed between the timing pulley 12 and the cam shaft 10, and
10 are connected. That is, the ring gear 38 is housed in the housing recess 32 of the timing pulley 12 which is sealed by the cap 33. The ring gear 38 has helical teeth on both teeth 38a and 38b provided on the inner and outer circumferences thereof, and is rotatable relative to the camshaft 10 by moving in the axial direction. The teeth 38a, 38b on the inner and outer circumferences of the ring gear 38 are the timing pulley 1
The two inner teeth 12 a and the inner teeth 33 a of the cap 33 are in mesh with each other. Further, the timing pulley 12 is drivingly connected to a crankshaft (not shown) via a timing belt 14 that is wound around its outer teeth 31. Therefore, when the driving force is transmitted from the crankshaft to the timing pulley 12 via the timing belt 14, the timing pulley 12 and the cap 33, which are further connected by the ring gear 38, are integrally rotated, and the camshaft 10 is rotationally driven. It At this time, ring gear 3
The cam shaft 10 is twisted with respect to the timing pulley 12 by moving the cam shaft 8 in the axial direction (the lateral direction in FIG. 3). As a result, the relative position of the camshaft 10 and the timing pulley 12 in the rotational direction is changed, and the opening / closing timing of the intake valve 8 is changed.
The rattling caused by the backlash of the ring gear 38 when the camshaft 10 is twisted is buffered by the action of the viscous coupling 37, and the generation of abnormal noise is suppressed.

In order to drive the ring gear 38 hydraulically, in the accommodating recess 32 of the timing pulley 12,
One end side of the ring gear 38 in the axial direction is a pressurizing chamber 39 into which hydraulic pressure of hydraulic oil is introduced. Similarly, in the accommodation recess 32, the other end of the ring gear 38 is a spring chamber 41 for accommodating a balancing spring 40 that opposes the hydraulic pressure. Further, a head oil passage 42 and a shaft oil passage 43, which communicate with each other, are formed in the cylinder head 1a of the engine 1 and the camshaft 10 in order to supply hydraulic pressure to the pressurizing chamber 39.

On the other hand, in order to drain the hydraulic oil from the pressurizing chamber 39, a part of the timing pulley 12 and the camshaft 10 is returned for discharging the hydraulic oil leaking from the pressurizing chamber 39 to the spring chamber 41. An oil passage 44 is formed.
In addition, the timing pulley 1 communicates with the return oil passage 44.
At one end side of 2, the camshaft 10 and the cylinder head 1
An oil recovery chamber 46 surrounded by a, the bearing cap 1b and the rubber seal 45 is provided. Furthermore,
At the lower position of the camshaft 10, the cylinder head 1a
An oil return hole 48 for returning the working oil recovered in the oil recovery chamber 46 to the oil pan 47 of the engine 1 is formed in a part of the above.

The upper side of the cylinder head 1a is covered with a head cover 49. Also, the cylinder head 1
A head oil passage 50 for supplying lubricating oil to the cam journal 10a is formed in a.

In this embodiment, the engine 1 is used as hydraulic oil.
Lubricating oil is used. That is, as shown in FIGS. 2 and 3, by driving the oil pump 51 linked to the operation of the engine 1, the lubricating oil accumulated in the oil pan 47 is sucked up. Then, the lubricating oil flows from the oil filter 52 to the first oil switching valve (OSV).
The hydraulic oil is supplied to the head oil passage 42 of the cylinder head 1 a via 53. The lubricating oil sucked up by the oil pump 51 is guided from the oil filter 52 to another head oil passage 50 and supplied to the cam journal 10a. On the other hand, the lubricating oil returned from the head oil passage 42 is
The oil is drained to the oil pan 47 through the drain second OSV 55.

The supply and release of hydraulic oil to the pressurizing chamber 39 is controlled by switching the first and second OSVs 53 and 54 on and off. That is, when the first OSV 53 is turned on and the second OSV 54 is turned off, hydraulic oil is supplied to the head oil passage 42, and the hydraulic oil is supplied to the head oil passage 4
2 is introduced into the pressurizing chamber 39 through the shaft oil passage 43. The hydraulic pressure causes the ring gear 38 to resist the urging force of the spring 40 in one axial direction (rightward in FIG. 3).
Is pushed to. As a result, the camshaft 10 is twisted and the rotational phase with respect to the timing pulley 12 is changed. That is, as shown in FIG. 5B, the opening / closing timing of the intake valve 8, that is, the opening / closing timing is advanced (advanced), and the intake valve 8 in the intake stroke is advanced.
The valve overlap between the exhaust valve 9 and the exhaust valve 9 is increased.

On the other hand, the first OSV 53 is turned off and the second OSV 53 is turned off.
When the OSV 54 is turned on, the supply of hydraulic oil to the head oil passage 42 is cut off. As a result, the hydraulic pressure is released in the pressurizing chamber 39, and the ring gear 38 is pressed back by the urging force of the spring 40 in the other axial direction (leftward in FIG. 3). As a result, an opposite twist is applied to the camshaft 10 and the rotational phase with respect to the timing pulley 12 is changed. That is, as shown in FIG. 5A, the opening / closing timing of the intake valve 8 is delayed (retarded), and the valve overlap in the intake stroke is reduced. At this time, the hydraulic oil leaking from the pressurizing chamber 39 to the spring chamber 41 is guided to the oil recovery chamber 46 through the return oil passage 44 and drained to the oil pan 47 through the oil return hole 48.

Each injector 16, the igniter 22, and the first and second OSVs 53, 54 are electrically connected to an electronic control unit (hereinafter simply referred to as "ECU") 70, and the EC
The operation of U70 controls their drive timing. The ECU 70 constitutes drive control means, determination means, selection means, deceleration state determination means, first valve timing target advance angle value selection means, and first and second advance angle amount change means. The intake air temperature sensor 61, the air flow meter 62, the throttle sensor 63, the oxygen sensor 64, the water temperature sensor 65, the rotation speed sensor 66, and the cylinder discrimination sensor 67 are connected to the ECU 70, respectively. The ECU 70, based on the output signals from the sensors 61, 63 to 67 and the air flow meter 62, the injectors 16, the igniter 22, the first and second OSVs 5, respectively.
3, 54 are preferably controlled. Next, the electrical configuration of the ECU 70 will be described with reference to the block diagram of FIG. The ECU 70 includes a central processing unit (CPU) 71, a read-only memory (ROM) 72 that stores a predetermined control program and the like in advance, a random access memory (RAM) 73 that temporarily stores the calculation results of the CPU 71, and pre-stored data. A backup RAM 74 for saving is provided. The ECU 70 is configured as a theoretical operation circuit in which the members 71 to 74, the external input circuit 75, the external output circuit 76, etc. are connected by a bus 77.

The external input circuit 75 includes the intake air temperature sensor 61, the air flow meter 62, and the throttle sensor 6 described above.
3, oxygen sensor 64, water temperature sensor 65, rotation speed sensor 6
6 and the cylinder discrimination sensor 67 are connected to each other.

On the other hand, the external output circuit 76 includes each injector 16, igniter 22, first OSV 53 and second injector 16.
OSV 54 of each is connected. And CP
U71 reads the output signals from the sensors 61, 63 to 67, the air flow meter 62, etc., which are input via the external input circuit 75, as input values. Further, the CPU 71 preferably controls the injectors 16, the igniter 22, the first and second OSVs 53, 54, etc. based on the read input values.

Next, the processing operation of the valve timing control executed by the above-mentioned ECU 70 will be described with reference to FIGS.
Follow the instructions below. The flowchart of FIG.
5 shows a "valve timing control routine" that is performed to switch the opening / closing timing of the intake valve 7 among the processes executed by the engine 1 every predetermined time ("10 ms" in this embodiment) during the operation of the engine 1. It is executed by the scheduled interrupt of.

When the processing shifts to this routine, first, at step 101, the intake air amount GN, the throttle opening TA and the engine speed NE are based on the respective output signals from the air flow meter 62, the throttle sensor 63 and the speed sensor 66. Respectively. Then, in step 102, it is determined whether the engine 1 is in the idle operation state. This determination is made based on the throttle opening TA read this time, the engine speed NE, and the like. Here, in the idle operation state,
In step 111, the first OSV 53 is turned off and the second OSV 54 is turned on in order to drive the VVT 23 and retard the opening / closing timing of the intake valve 8. Then, after the processing of step 111 is completed, the subsequent processing is once completed.

On the other hand, if it is determined in step 102 that the engine is not idle, the throttle opening detected in the previous routine in step 103 is used as the predetermined address T of the RAM 73.
Store in AO. Next, at step 104, the current throttle opening TA is stored in a predetermined address TAN of the RAM 73, and the routine proceeds to step 105. At step 105, the previous throttle opening is subtracted from the current throttle opening,
Set ΔTA. At the next step 106, ΔTA
Is smaller than a predetermined value X. If it is equal to or greater than the predetermined value X, it is determined that the vehicle is not decelerating, and the process proceeds to step 108. In step 108, the throttle opening TA
The target advance amount OCAM is calculated based on the map of the engine speed NE and the engine speed NE, and the routine proceeds to step 109. On the other hand, if ΔTA is less than the predetermined value X in step 106, it is determined that the vehicle is decelerating, and the process proceeds to step 107.
In step 107, the target advance amount OCAM is calculated based on the map of the intake air amount GN and the engine speed NE, and the process proceeds to step 109. And step 1
In 09, the target advance value OCAM calculated this time is
Judges whether to advance or retard. Then, step 109
At, the target advance value OCAM of the engine 1 is “advance”
If so, in step 110, the VVT 23
The first OSV 53 is turned on and the second OSV 54 is turned off in order to advance the opening / closing timing of the intake valve 8 by driving. And this step 110
After the processing of (1) is finished, the subsequent processing is once finished.

On the other hand, in step 109, if the target advance value of the engine 1 is not "advance", that is, "retard", the process proceeds to step 110 and the same processing as described above is executed. After that, the subsequent processing is once terminated.

As described above, the valve timing control for changing the opening / closing timing of the intake valve 8 is executed. As described above, in this embodiment, when controlling the opening / closing timing of the intake valve 8, whether the "advance" or the "retard" is determined by a map of the throttle opening TA and the engine speed NE, or the intake air. The determination is made by referring to the map of the amount GN and the engine speed NE. And
According to the result of the determination, the first and second OSVs 53, 54
VVT23 is driven by turning on and off,
The opening / closing timing of the intake valve 8 is changed to the advance side or the retard side. In addition, the valve overlap between the intake valve 8 and the exhaust valve 9 is changed accordingly.

In this embodiment, one end of the ring gear 38 in the axial direction is driven by the hydraulic oil and the other end of the ring gear 38 is driven by the spring 40, so that the operation in the retard angle direction is compared with the operation in the advance angle direction. It has fast characteristics. Further, during deceleration, there are more operations in the retard direction than in the advance direction, but in this embodiment, the target advance value (see A in FIG. 8) is obtained from the GN-NE map during deceleration. , Fig. 8
As shown in, it is possible to obtain a value close to the target advance value obtained from the actual air amount. Therefore, according to this embodiment, FIG.
The VVT advance amount shown by C in FIG. Note that FIG.
The VVT advance amount shown in D is the same as the conventional TA- during deceleration.
It is the VVT advance amount when the target advance value is obtained from the NE map and the target advance value is controlled.

As described above, in this embodiment, at the time of deceleration, T
Since the target advance value (see A in FIG. 8) is obtained on the GN-NE map that is on the advance side of the target advance value obtained from the A-NE map, the target advance value obtained by the actual air amount A value close to can be obtained. Therefore, the responsiveness can be improved without causing an excessive deviation from the actual operating condition.

Also, unlike the conventional case, the internal retardation angle does not become excessively retarded, so that the internal EGR can be sufficiently secured.
Generation of Ox can be suppressed and fuel consumption can be improved.
In this embodiment, in the idle operation state, the opening / closing timing of the intake valve 8 is retarded, so the opening of the intake valve 8 immediately before the transition from the exhaust stroke to the intake stroke is delayed, and the valve overlap is reduced. . Therefore, in this operating region, the intake air is properly introduced into the combustion chamber 4 in accordance with the amount and the momentum of the intake air, and the idle operation can be stabilized.

Next, a second embodiment will be described with reference to FIGS. In this embodiment, in the configuration of the first embodiment, step 200 is replaced by step 200, step 107 is replaced by step 201, and step 1 is executed.
The difference is that the processing of step 202 is performed instead of 08. The ECU 70 constitutes drive control means, determination means, selection means, acceleration state determination means, second valve timing target advance angle value selection means, and third advance angle amount change means.

That is, in step 200, Δ
It is determined whether TA is smaller than a predetermined value Y. If the value is equal to or less than the predetermined value Y, it is determined that it is not during acceleration, and step 20
Move to 2. In step 202, intake air amount GN
The target advance amount OCAM is calculated based on the map of the engine speed NE and the engine speed NE, and the routine proceeds to step 109.

On the other hand, if ΔTA exceeds the predetermined value Y in step 200, it is determined that the vehicle is accelerating, and the process proceeds to step 201. In step 201, the target advance amount OCAM is calculated on the basis of the map of the throttle opening TA and the engine speed NE, and the process proceeds to step 109. Also in this second embodiment, one end side of the ring gear 38 in the axial direction is operated by hydraulic oil. Since it is driven and the other end in the axial direction is driven by the spring 40, it has a characteristic that the operation in the advance direction is slower than the operation in the retard direction.

Further, at the time of acceleration, the operation in the advance direction is more frequent than the operation in the retard angle direction, but in this embodiment, the target advance value (see E in FIG. 12) on the TA-NE map at the time of acceleration. Ask for. Therefore, according to this embodiment, G of FIG.
The VVT advance angle amount as shown in FIG. Note that the VVT advance amount shown in H of FIG. 13 is the same as that of the conventional GN-N during acceleration.
It is the VVT advance amount when the target advance value is obtained from the E map and the target advance value is controlled.

As described above, in this embodiment, GN is set at the time of acceleration.
In order to obtain the target advance value (see E in FIG. 12) on the TA-NE map that is on the advance side of the target advance value obtained from the NE map, the target advance value of the actual air amount It will be too fast than the ones. However, since the operation of the VVT 23 is sufficiently slow with respect to the change in the target advance angle value obtained by the TA-NE map, the VVT 23 approaches the rising when the actual air amount is controlled, and the target advance angle obtained by the GN-NE map is approached. The followability is improved as compared with the case of controlling with a value.

Therefore, since the internal EGR can be sufficiently secured, the generation of HC and NOx can be suppressed and the fuel consumption can be improved. The present invention is not limited to the above-described embodiments, and a part of the configuration may be appropriately modified without departing from the spirit of the present invention, and the present invention may be implemented as follows.

(1) In the above embodiment, two OSV5
Although the hydraulic VVT 23 whose drive is switched by 3, 54 is used, the present invention is not limited to this and one OS is used.
A VVT whose drive is switched using V may be used.

(2) The controls of both the embodiments may be embodied so that they can be processed together. (3) In the second embodiment, one end surface in the axial direction of the ring gear 38 is driven by hydraulic oil, but it is embodied in a hydraulically driven variable valve timing mechanism in which both axial end surfaces are driven by hydraulic oil. May be.

[0060]

As described above in detail, according to the present invention, high valve timing responsiveness can be obtained during acceleration and deceleration. Then, it is possible to improve the responsiveness without causing an excessive deviation from the actual driving condition, to sufficiently secure the internal EGR, and to improve the fuel efficiency.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram illustrating a basic conceptual configuration of the present invention.

FIG. 2 is a schematic configuration diagram showing a valve timing control device for an internal combustion engine in a first embodiment embodying the present invention.

FIG. 3 is a sectional view showing a structure of VVT and the like.

FIG. 4 is a block diagram showing a configuration of an ECU and the like.

5A and 5B also illustrate the relationship between the opening and closing timings of the intake valve and the exhaust valve, FIG. 5A is an explanatory diagram when the opening and closing timings of the intake valves are retarded, and FIG. 5B is an advance timing of the opening and closing timings of the intake valves. It is explanatory drawing at the time of making it.

FIG. 6 is a flowchart illustrating a “valve timing control routine” that is also executed by the ECU.

FIG. 7 is an explanatory diagram showing a throttle opening with respect to time during deceleration.

FIG. 8 is an explanatory diagram showing a case where a target advance value is obtained from a map of intake air amount and engine speed during deceleration and a target advance value is obtained from a map of throttle opening and engine speed. .

FIG. 9 shows a VVT advance amount when controlled based on a map of intake air amount and engine speed during deceleration, and a VVT advance amount when controlled based on a map of throttle opening and engine speed. It is a characteristic diagram.

FIG. 10 is a flowchart illustrating a “valve timing control routine” executed by the ECU of the second embodiment.

FIG. 11 is an explanatory diagram showing a throttle opening degree with respect to time during acceleration.

FIG. 12 is an explanatory diagram showing a case where a target advance value is obtained from a map of intake air amount and engine speed during acceleration, and a case where a target advance value is obtained from a map of throttle opening and engine speed. .

FIG. 13 shows a VVT advance angle amount when controlled based on a map of intake air amount and engine speed during acceleration, and a VVT advance amount when controlled based on a map of throttle opening and engine speed. It is a characteristic diagram.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine as an internal combustion engine, 4 ... Combustion chamber, 6 ... Intake passage, 7 ... Exhaust passage, 8 ... Intake valve, 9 ... Exhaust valve, 23 ... Variable valve timing mechanism (VVT), 62
… Air flow meter, 63… Throttle sensor, 66…
Rotational speed sensor (62, 63, 65, 66 constitutes operating state detecting means), 70 ... ECU (drive control means,
Judgment means, selection means, deceleration state judgment means, acceleration state judgment means, first valve timing target advance value selection means, second valve timing target advance value selection means, and first to third advance amounts Constitutes a means of change).

Claims (3)

[Claims] 1. An intake valve and an exhaust valve which are driven at a predetermined timing in synchronization with the rotation of an internal combustion engine to open and close an intake passage and an exhaust passage communicating with a combustion chamber, and at least one of the intake valve and the exhaust valve. A variable valve timing mechanism for driving the valve to vary the valve overlap amount, an operating state detecting means for detecting an operating state of the internal combustion engine, and the valve overflow based on the detection result of the operating state detecting means. A valve timing control device for an internal combustion engine, comprising: a drive control means for driving and controlling the variable valve timing mechanism to control a lap amount; a determining means for determining a specific engine state based on a detection result of the operating state detecting means; , In the specific engine state judged by the judging means, inhalation is performed based on the detection result of the driving state detecting means. Of the target advance value of valve timing obtained from the air volume and the engine speed, and the target advance value of valve timing obtained from the throttle opening and the engine speed based on the detection result of the operating state detection means. Selecting means for selecting a target advance value of the valve timing whose target advance value is on the advance side; and the variable valve timing mechanism in the drive control means at the target advance value of the valve timing selected by the selecting means. And a first advance angle changing means for changing the control range of the valve timing control apparatus for an internal combustion engine. 2. An intake valve and an exhaust valve, which are driven at a predetermined timing in synchronization with the rotation of an internal combustion engine to open and close an intake passage and an exhaust passage communicating with a combustion chamber, and at least one of the intake valve and the exhaust valve. A variable valve timing mechanism for driving the valve to vary the valve overlap amount, an operating state detecting means for detecting an operating state of the internal combustion engine, and the valve overlap based on the detection result of the operating state detecting means. A valve timing control device for an internal combustion engine, comprising: a drive control means for driving and controlling the variable valve timing mechanism to control an amount of the variable valve timing mechanism; Decelerating state determining means, and when the decelerating state determining means determines that the vehicle is decelerating, it detects the operating state detecting means. First valve timing target advance value selection means for selecting a target advance value of valve timing obtained from the intake air amount and engine speed based on the result; and the first valve timing target advance value selection means. Valve timing of the internal combustion engine, further comprising: second advance angle changing means for changing the control range of the variable valve timing mechanism in the drive control means at the target advance value of the valve timing selected by Control device. 3. An intake valve and an exhaust valve, which are driven at a predetermined timing in synchronization with the rotation of an internal combustion engine to open and close an intake passage and an exhaust passage communicating with a combustion chamber, and at least one of the intake valve and the exhaust valve. A variable valve timing mechanism for driving the valve to vary the valve overlap amount, an operating state detecting means for detecting an operating state of the internal combustion engine, and the valve overlap based on the detection result of the operating state detecting means. In a valve timing control device for an internal combustion engine, comprising: a drive control means for driving and controlling the variable valve timing mechanism to control the amount of the variable valve timing mechanism; The acceleration state determining means, and when the acceleration state determining means determines that the vehicle is accelerating, the operating state detecting means detects the acceleration state. Second valve timing target advance value selecting means for selecting a target advance value of valve timing obtained from throttle opening and engine speed based on the result; and second valve timing target advance value selecting means Valve timing of the internal combustion engine, further comprising: third advance angle changing means for changing the control range of the variable valve timing mechanism in the drive control means at the target advance value of the valve timing selected by Control device.